Clinical characteristics of COPD patients with early-onset desaturation in the 6-minute walk test

array:24 ["pii" => "S253104371830076X" "issn" => "25310437" "doi" => "10.1016/j.pulmoe.2018.04.007" "estado" => "S300" "fechaPublicacion" => "2018-09-01" "aid" => "35" "copyright" => "Sociedade Portuguesa de Pneumologia" "copyrightAnyo" => "2018" "documento" => "article" "crossmark" => 1 "licencia" => "http://creativecommons.org/licenses/by-nc-nd/4.0/" "subdocumento" => "fla" "cita" => "Pulmonol. 2018;24:275-9" "abierto" => array:3 [ "ES" => true "ES2" => true "LATM" => true ] "gratuito" => true "lecturas" => array:2 [ "total" => 1296 "formatos" => array:3 [ "EPUB" => 172 "HTML" => 698 "PDF" => 426 ] ] "itemSiguiente" => array:19 [ "pii" => "S2531043718300461" "issn" => "25310437" "doi" => "10.1016/j.pulmoe.2018.02.007" "estado" => "S300" "fechaPublicacion" => "2018-09-01" "aid" => "20" "copyright" => "Sociedade Portuguesa de Pneumologia" "documento" => "article" "crossmark" => 1 "licencia" => "http://creativecommons.org/licenses/by-nc-nd/4.0/" "subdocumento" => "fla" "cita" => "Pulmonol. 2018;24:280-8" "abierto" => array:3 [ "ES" => true "ES2" => true "LATM" => true ] "gratuito" => true "lecturas" => array:2 [ "total" => 1593 "formatos" => array:3 [ "EPUB" => 188 "HTML" => 953 "PDF" => 452 ] ] "en" => array:12 [ "idiomaDefecto" => true "cabecera" => "Original article" "titulo" => "Chronic respiratory failure in patients with chronic obstructive pulmonary disease under home noninvasive ventilation: Real-life study" "tienePdf" => "en" "tieneTextoCompleto" => "en" "tieneResumen" => "en" "paginas" => array:1 [ 0 => array:2 [ "paginaInicial" => "280" "paginaFinal" => "288" ] ] "contieneResumen" => array:1 [ "en" => true ] "contieneTextoCompleto" => array:1 [ "en" => true ] "contienePdf" => array:1 [ "en" => true ] "resumenGrafico" => array:2 [ "original" => 0 "multimedia" => array:7 [ "identificador" => "fig0005" "etiqueta" => "Figure 1" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr1.jpeg" "Alto" => 1104 "Ancho" => 2410 "Tamanyo" => 95703 ] ] "descripcion" => array:1 [ "en" => "Clinical conditions causing CHRF in the 334 patients treated with home NIV at the noninvasive respiratory care unit of Hospital Pulido Valente between August 2011 and July 2014. COPD, chronic obstructive pulmonary disease; OHS, obesity hypoventilation syndrome; NMD, neuromuscular disease." ] ] ] "autores" => array:1 [ 0 => array:2 [ "autoresLista" => "V. Durão, M. Grafino, P. Pamplona" "autores" => array:3 [ 0 => array:2 [ "nombre" => "V." "apellidos" => "Durão" ] 1 => array:2 [ "nombre" => "M." "apellidos" => "Grafino" ] 2 => array:2 [ "nombre" => "P." "apellidos" => "Pamplona" ] ] ] ] ] "idiomaDefecto" => "en" "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/S2531043718300461?idApp=UINPBA00004E" "url" => "/25310437/0000002400000005/v1_201810040621/S2531043718300461/v1_201810040621/en/main.assets" ] "itemAnterior" => array:18 [ "pii" => "S2531043718301302" "issn" => "25310437" "doi" => "10.1016/j.pulmoe.2018.09.002" "estado" => "S300" "fechaPublicacion" => "2018-09-01" "aid" => "1310" "documento" => "simple-article" "crossmark" => 1 "licencia" => "http://creativecommons.org/licenses/by-nc-nd/4.0/" "subdocumento" => "edi" "cita" => "Pulmonol. 2018;24:273-4" "abierto" => array:3 [ "ES" => true "ES2" => true "LATM" => true ] "gratuito" => true "lecturas" => array:2 [ "total" => 1457 "formatos" => array:3 [ "EPUB" => 158 "HTML" => 916 "PDF" => 383 ] ] "en" => array:9 [ "idiomaDefecto" => true "titulo" => "It's been a hard day's night…But it was worth every minute" "tienePdf" => "en" "tieneTextoCompleto" => "en" "paginas" => array:1 [ 0 => array:2 [ "paginaInicial" => "273" "paginaFinal" => "274" ] ] "contieneTextoCompleto" => array:1 [ "en" => true ] "contienePdf" => array:1 [ "en" => true ] "resumenGrafico" => array:2 [ "original" => 0 "multimedia" => array:7 [ "identificador" => "fig0005" "etiqueta" => "Fig. 1" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr1.jpeg" "Alto" => 806 "Ancho" => 1549 "Tamanyo" => 52738 ] ] "descripcion" => array:1 [ "en" => "RPP Impact Factor evolution in the last five years." ] ] ] "autores" => array:1 [ 0 => array:2 [ "autoresLista" => "António Morais" "autores" => array:1 [ 0 => array:2 [ "nombre" => "António" "apellidos" => "Morais" ] ] ] ] ] "idiomaDefecto" => "en" "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/S2531043718301302?idApp=UINPBA00004E" "url" => "/25310437/0000002400000005/v1_201810040621/S2531043718301302/v1_201810040621/en/main.assets" ] "en" => array:18 [ "idiomaDefecto" => true "cabecera" => "Original article" "titulo" => "Clinical characteristics of COPD patients with early-onset desaturation in the 6-minute walk test" "tieneTextoCompleto" => true "paginas" => array:1 [ 0 => array:2 [ "paginaInicial" => "275" "paginaFinal" => "279" ] ] "autores" => array:1 [ 0 => array:4 [ "autoresLista" => "I. García-Talavera, J.M. Figueira-Gonçalves, N. Gurbani, L. Pérez-Méndez, A. Pedrero-García" "autores" => array:5 [ 0 => array:4 [ "nombre" => "I." "apellidos" => "García-Talavera" "email" => array:1 [ 0 => "igarmark@gmail.com" ] "referencia" => array:2 [ 0 => array:2 [ "etiqueta" => "a" "identificador" => "aff0005" ] 1 => array:2 [ "etiqueta" => "*" "identificador" => "cor0005" ] ] ] 1 => array:3 [ "nombre" => "J.M." "apellidos" => "Figueira-Gonçalves" "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "a" "identificador" => "aff0005" ] ] ] 2 => array:3 [ "nombre" => "N." "apellidos" => "Gurbani" "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "a" "identificador" => "aff0005" ] ] ] 3 => array:3 [ "nombre" => "L." "apellidos" => "Pérez-Méndez" "referencia" => array:2 [ 0 => array:2 [ "etiqueta" => "b" "identificador" => "aff0010" ] 1 => array:2 [ "etiqueta" => "c" "identificador" => "aff0015" ] ] ] 4 => array:3 [ "nombre" => "A." "apellidos" => "Pedrero-García" "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "b" "identificador" => "aff0010" ] ] ] ] "afiliaciones" => array:3 [ 0 => array:3 [ "entidad" => "Pneumology Service and Thoracic Surgery, University Hospital Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain" "etiqueta" => "a" "identificador" => "aff0005" ] 1 => array:3 [ "entidad" => "Division of Clinical Epidemiology and Biostatistics, Research Unit, University Hospital Nuestra Señora de Candelaria, and Primary Care Management, Santa Cruz de Tenerife, Spain" "etiqueta" => "b" "identificador" => "aff0010" ] 2 => array:3 [ "entidad" => "Networked Biomedical Research Centre (CIBER) of Respiratory Diseases, Carlos III Health Institute, Madrid, Spain" "etiqueta" => "c" "identificador" => "aff0015" ] ] "correspondencia" => array:1 [ 0 => array:3 [ "identificador" => "cor0005" "etiqueta" => "⁎" "correspondencia" => "Corresponding author." ] ] ] ] "resumenGrafico" => array:2 [ "original" => 0 "multimedia" => array:7 [ "identificador" => "fig0005" "etiqueta" => "Figure 1" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr1.jpeg" "Alto" => 1271 "Ancho" => 1604 "Tamanyo" => 68461 ] ] "descripcion" => array:1 [ "en" => "BMI in early and non early desaturators patients." ] ] ] "textoCompleto" => "IntroductionExercise-induced oxygen desaturation (EID) occurs in up to 20% of the patients with chronic obstructive pulmonary disease (COPD).<a class="elsevierStyleCrossRef" href="#bib0090">1</a> However, despite being a relatively frequent condition, its definition has not yet been agreed upon.<a class="elsevierStyleCrossRefs" href="#bib0095">2–4</a> The most widely accepted criterion in common practice comprises a drop in oxygen saturation (SatO2) of more than 4% with a nadir of at least 88%. Although the pathophysiology of EID is a matter of debate, aspects such as the severity of airflow obstruction, a low CO diffusion capacity (DLCO), a high degree of emphysema, obesity, and a SatO2 at rest ≤93% have been related to it.<a class="elsevierStyleCrossRefs" href="#bib0110">5–8</a>Studies carried out by our group show that the decrease in the SatO2 curve during the 6-minute walk test (6MWT) has prognostic implications. Patients with such an event before the end of the first minute of the test, termed ‘early desaturators’ (EDs), had a high probability of also experiencing them during their daily life activities and of additionally developing hypoxaemic respiratory failure at rest within the subsequent 5 years compared to subjects who desaturated after 3min.<a class="elsevierStyleCrossRefs" href="#bib0130">9,10</a> Given the occurrence of the two desaturation profiles in patients with the same disease, the assessment of possible differential factors associated with this behaviour is imperative.The purpose of this study was to characterise COPD patients with early desaturation versus non-early desaturation as well as determine potential markers that point to events of EID before the end of the first minute.MethodsPatientsFrom a pool of 163 patients with COPD and exercise desaturation on the 6min walking test registered on our laboratory data base, 57 were not selected because they had interstitial disease, severe cardiac disease, domiciliary oxygentherapy. Then we conducted a cross-sectional study in 106 COPD (<a class="elsevierStyleCrossRef" href="#tbl0005">Table 1</a>) patients, normoxaemic at rest but experiencing EID. The inclusion criteria were: aged over 40 years, active or former smoker with a pack-year index (PYI) >10 and a post-bronchodilator ratio of forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) <70%, in addition to a basal SatO2 >90%. Patients with SatO2 at rest ≤90% or who were not able to correctly perform the 6MWT were excluded.<elsevierMultimedia ident="tbl0005"></elsevierMultimedia>MeasurementsThe following data from this descriptive, observational study was collected retrospectively from computerised medical records: age; sex; smoking history (active smokers if they had smoked at least one cigarette in the course of the foregoing 6 months; former smokers if they had maintained continuous abstinence for at least 6 months); smoking intensity by means of the PYI (defined as the number of packs of cigarettes smoked per day multiplied by the number of years as a smoker and divided by 20); body mass index (BMI) following the SEEDO<a class="elsevierStyleCrossRef" href="#bib0140">11</a> criteria; dyspnoea (modified Medical Research Council [mMRC] scale); comorbidity (assessed by means of the Charlson index); BODE index; the associated cardiovascular risk factors arterial hypertension Type 2 diabetes mellitus, dyslipidaemia, and obesity; and finally cardiovascular diseases such as arrhythmia, ischaemic heart disease, and congestive heart failure. In addition, we recorded the results of the following pulmonary function tests: FEV1, FVC, FEV1/FVC, inspiratory capacity (IC), residual volume, total lung capacity, and lung diffusion capacity for CO (DLCO). Patients were stratified according to the four degrees of airflow obstruction collected in the 2009 GOLD (Global Initiative for Chronic Obstructive Lung Disease guidelines.<a class="elsevierStyleCrossRef" href="#bib0145">12</a>The 6MWT was performed in a 30-m long corridor following the ATS/ERS<a class="elsevierStyleCrossRef" href="#bib0150">13</a> protocol. Briefly, all tests were performed without supplemental oxygen and supervised by two observers, who instructed the patients to walk 6min along the corridor to complete as many metres as possible. Patients were allowed to stop if they had dyspnoea and resume walking when the symptoms had disappeared. The following variables were collected: initial and minimum SatO2, metres walked during the 6min of the test, as well as the point in time at which the SatO2 had come to the threshold of 90% (T90). EID was defined as a 4% drop in SatO2 from baseline, reaching a minimum of 88% or lower. Patients who desaturated during exercise within the first minute of the 6MWT were defined EDs and those who did so at a later point in time as non-early desaturators (NEDs).Statistical analysisData were summarised as frequencies for categorical variables, as mean±SD for normally distributed data, and median (25th–75th percentile) for non-normally distributed outcome data. Comparisons between the groups ED and NED were explored using Pearson Chi-squared test, the Mann–Whitney U-test, and Student t-test as appropriate.Differential patient characteristics before performing the 6MWT test were BMI and initial pulse oximetre saturation (SpO2) (<a class="elsevierStyleCrossRef" href="#tbl0005">Table 1</a>). We applied multivariate logistic regression analysis, adjusted by initial SpO2, to determine the association between BMI and ED. Finally, to evaluate the discriminative capacity of the continuous BMI scale as a possible marker of ED, a receiver operator characteristic (ROC) curve was generated and the area underneath the curve (AUC) calculated.The sample size (n=106) was estimated based on a frequency-of-outcomes factor of at least 20% of ED in the population with a confidence interval of 95% and a beta error of 20%. The significance level was established as p<0.05. All analyses were performed with the SPSS/PC statistical programme (version 21.0 for Windows; SPSS, Inc., Chicago, IL, USA). The study was approved by the ethics committee of the University Hospital Nuestra Señora de Candelaria (Tenerife, Spain).ResultsSubject characteristicsA total of 106 patients were included in this study, all of them had COPD diagnosed and were staged as per GOLD guidelines. All patients desaturated either before or after the first minute of the 6MWT. The patients’ characteristics are reflected in <a class="elsevierStyleCrossRef" href="#tbl0005">Table 1</a>. Most of them were men (ratio 4/1) with a median age of 68 years and a predicted FEV1 of 46%. The baseline oxygen saturation was above 90%. 93% of patients had moderate to severe airflow limitation and a high risk measured by BODE scale. Thirty two subjects (30%) were classified as EDs.Differences between ED and NED<a class="elsevierStyleCrossRef" href="#tbl0010">Table 2</a> compares the baseline characteristics of the ED versus the NED group, which resembled each other in age, GOLD stages with most of the subjects suffering from moderate to severe obstruction, as well as BODE and Charlson index. Hypertension and dyslipidaemia were the most frequent comorbidities in general; no differences were observed in mortality. When performing the 6MWT, differential BMI values became evident. The mean BMI was higher in ED than in NED patients with an inverse relation as to the categorical BMI levels <25, 25–29, and ≥30 (p for trends=0.011; <a class="elsevierStyleCrossRef" href="#fig0005">Fig. 1</a>).<elsevierMultimedia ident="tbl0010"></elsevierMultimedia><elsevierMultimedia ident="fig0005"></elsevierMultimedia>Although we observed a significantly lower mean initial SpO2, this was clinically not relevant. Therefore its influence was adjusted in the multivariate analysis using the quartil of initial SpO2. The probability of ED during exercise increased by 1.79 (ORajusted) in overweight and obese patients (95% CI 1.12–2.86; p=0.015).Finally, the area under the curves showed the discriminative capacity of the continuous scale for BMI analysis: AUC=70% (95% CI, 60–81%; p=0.001; <a class="elsevierStyleCrossRef" href="#fig0010">Fig. 2</a>).<elsevierMultimedia ident="fig0010"></elsevierMultimedia><a class="elsevierStyleCrossRef" href="#tbl0010">Table 2</a> also reflects the distribution of clinical, functional parameters and lung function. We did not detect any differences in static functional respiratory parameters except that EDs had a lower FEV1/FVC index than NEDs. ED patients also walked 64m less (mean) in the 6MWT (p=0.011), and they desaturated more deeply (10.7±4.6% versus 8.6±3.5%; p=0.025).DiscussionEID is the result of a mismatch between ventilation and perfusion during physical effort. Airflow limitation and loss of lung elasticity lead to increased air trapping and dynamic hyperinflation, increasing patient inspiratory work and thereby increasing oxygen consumption in COPD patients.<a class="elsevierStyleCrossRefs" href="#bib0100">3,13,14</a> Until a few years ago, this phenomenon observed during the 6MWT, did not provide any further information than that of the change in SatO2. It was considered a mere curiosity, which appeared in a group of COPD patients but did not translate into a change in medical attitude, perception of poor prognosis or treatment modification. Takigawa et al.<a class="elsevierStyleCrossRef" href="#bib0160">15</a> demonstrated that, in addition to the distance walked in the 6MWT, the variation in SatO2 also had prognostic implications. Later, the phenomenon came to be no longer regarded as an unimportant fact, but one to be taken into account together with parameters such as the metres covered in the 6MWT, the FEV1, and the oxygen partial pressure in blood. A few years later, these findings were corroborated by the ECLIPSE<a class="elsevierStyleCrossRef" href="#bib0125">8</a> group, who demonstrated that both desaturation and the frequency of stops during the walk test were prognostic factors. However, the possible different types of desaturation have not yet been well characterised, neither in terms of their definition, which remains ambiguous, nor addressing the different forms as to the distinction between basal and minimal desaturation, its quality and nature. We defined a category, termed ED, to differentiate it from late and intermediate desaturation. This was the result of a study where we compared desaturation in two different settings, the 6MWT and daily life activities. Only the patients who desaturated within the first minute of the test also did so outside the hospital in their daily activities, something that was not true of those who desaturated only after 3.5min.<a class="elsevierStyleCrossRef" href="#bib0130">9</a> Therefore, early desaturation in the 6MWT is a relevant aspect, because it implies desaturation during everyday activities and under low levels of physical strain. In addition to this aspect, the ED patient group is more likely to develop respiratory insufficiency over time than the NEDs. Hence, the elapsed time to desaturation in the 6MWT is a useful variable, which provides information of clinical interest. Additional potential markers to consider are the depth and persistence of desaturation. Of note, early desaturation also tends to be deep; according to our observations in this study, the nadir is very low. We were interested in defining a profile of patients who desaturate early and analyse clinical and functional characteristics to identify potential differential parameters between EDs and patients who desaturate after the first minute of the 6MWT. Like other authors,<a class="elsevierStyleCrossRefs" href="#bib0095">2,6</a> we found that desaturation is typical of patients with low FEV1 and relatively low baseline DLCO and SatO2 values. But it remained to be determined whether there was a defined profile for ED patients. We did not observe differences in either age or FEV1 values, and although DLCO was somewhat lower in EDs, this was not statistically significant. From a functional point of view, basal SatO2 and the distance walked in the 6MWT were significantly lower in EDs compared to the NED group, and it should be emphasised that the desaturation in the ED group was more profound, which may be considered as another feature of severity. However, BMI was the most outstanding parameter in the ED group. These patients were more obese, although this was not associated with comorbidities such as ischaemic heart disease, cardiac arrhythmia, or AHT. Recently, Andrianopoulos et al.<a class="elsevierStyleCrossRef" href="#bib0125">8</a> analysed patients from the ECLIPSE cohort and described obesity as a factor involved in EID (OR 1.57, 95% CI 1.15–2.14) along with additional parameters, such as a high degree of airflow obstruction and low DLCO values. While obesity has been linked to low baseline SatO2 and EID,<a class="elsevierStyleCrossRefs" href="#bib0125">8,16</a> our study adds that this feature appears to be limited to ED COPD patients.COPD patients may exhibit very diverse characteristics, which depend on the association with other conditions such as bronchial asthma, sleep apnoea, and fibrosis. EID occurs preferentially in severe patients with low DLCO values; although, unexpectedly, it is not observed in lean but in obese patients. Early desaturation, which we think is of great importance because it translates to increased severity, is preferentially observed in subjects with a BMI ≥30. Alterations in respiratory mechanics or higher levels of proinflammatory cytokines such as leptin may possibly explain this phenomenon.<a class="elsevierStyleCrossRef" href="#bib0170">17</a>There are some limitations; the study is retrospective, the number of patients is not very high, the proportion of women is very low, we did not select non-smoker patients and the study only took place in hospital.In summary, we would like to draw special attention to COPD patients with severe to very severe obstruction, low DLCO, and overt obesity, because they may experience early and profound desaturation during exercise and, together with the obesity, suffer from very harmful long-term effects.FundingMenarini SA Corp Foundation.Conflicts of interestThe authors have no conflicts of interest to declare." "textoCompletoSecciones" => array:1 [ "secciones" => array:9 [ 0 => array:3 [ "identificador" => "xres1090337" "titulo" => "Abstract" "secciones" => array:4 [ 0 => array:2 [ "identificador" => "abst0005" "titulo" => "Background" ] 1 => array:2 [ "identificador" => "abst0010" "titulo" => "Methods" ] 2 => array:2 [ "identificador" => "abst0015" "titulo" => "Results" ] 3 => array:2 [ "identificador" => "abst0020" "titulo" => "Conclusion" ] ] ] 1 => array:2 [ "identificador" => "xpalclavsec1033630" "titulo" => "Keywords" ] 2 => array:2 [ "identificador" => "sec0005" "titulo" => "Introduction" ] 3 => array:3 [ "identificador" => "sec0010" "titulo" => "Methods" "secciones" => array:3 [ 0 => array:2 [ "identificador" => "sec0015" "titulo" => "Patients" ] 1 => array:2 [ "identificador" => "sec0020" "titulo" => "Measurements" ] 2 => array:2 [ "identificador" => "sec0025" "titulo" => "Statistical analysis" ] ] ] 4 => array:3 [ "identificador" => "sec0030" "titulo" => "Results" "secciones" => array:2 [ 0 => array:2 [ "identificador" => "sec0035" "titulo" => "Subject characteristics" ] 1 => array:2 [ "identificador" => "sec0040" "titulo" => "Differences between ED and NED" ] ] ] 5 => array:2 [ "identificador" => "sec0045" "titulo" => "Discussion" ] 6 => array:2 [ "identificador" => "sec0050" "titulo" => "Funding" ] 7 => array:2 [ "identificador" => "sec0055" "titulo" => "Conflicts of interest" ] 8 => array:1 [ "titulo" => "References" ] ] ] "pdfFichero" => "main.pdf" "tienePdf" => true "fechaRecibido" => "2017-09-15" "fechaAceptado" => "2018-04-07" "PalabrasClave" => array:1 [ "en" => array:1 [ 0 => array:4 [ "clase" => "keyword" "titulo" => "Keywords" "identificador" => "xpalclavsec1033630" "palabras" => array:3 [ 0 => "COPD" 1 => "Exercise desaturation" 2 => "6 min walking test" ] ] ] ] "tieneResumen" => true "resumen" => array:1 [ "en" => array:3 [ "titulo" => "Abstract" "resumen" => "BackgroundExercise-induced desaturation in chronic obstructive pulmonary disease (COPD) frequently has prognostic implications. Desaturation within the first minute of the walk 6-minute walk test will probably also occur in daily life activities and translate into hypoxaemic respiratory failure at rest in later years. This study aimed at comparing these patients with those who desaturate after the first minute and determine potential markers. MethodsWe conducted a cross-sectional, retrospective study collecting data on respiratory function tests, cardiovascular comorbidity, body mass index, pack-year index, 6-minute walk test outcomes, BODE index, and Charlson comorbidity index. Patients who desaturated during the first minute of the test were referred to as early desaturators compared to the non-early ones. ResultsWe observed a higher mean body mass index in early desaturating patients, and an inverse relation as to the body mass index categories <25, 25–29, and ≥30. Early desaturators had a lower FEV1/FVC index. The mean distance walked in the test was shorter in early than in non-early desaturators, and they desaturated more deeply. ConclusionOverweight and obesity, as determined by body mass index, seem to behave like markers for early desaturation. This simple anthropometric measure might indicate point to potential early desaturation in COPD patients." "secciones" => array:4 [ 0 => array:2 [ "identificador" => "abst0005" "titulo" => "Background" ] 1 => array:2 [ "identificador" => "abst0010" "titulo" => "Methods" ] 2 => array:2 [ "identificador" => "abst0015" "titulo" => "Results" ] 3 => array:2 [ "identificador" => "abst0020" "titulo" => "Conclusion" ] ] ] ] "multimedia" => array:4 [ 0 => array:7 [ "identificador" => "fig0005" "etiqueta" => "Figure 1" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr1.jpeg" "Alto" => 1271 "Ancho" => 1604 "Tamanyo" => 68461 ] ] "descripcion" => array:1 [ "en" => "BMI in early and non early desaturators patients." ] ] 1 => array:7 [ "identificador" => "fig0010" "etiqueta" => "Figure 2" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr2.jpeg" "Alto" => 1660 "Ancho" => 1590 "Tamanyo" => 99591 ] ] "descripcion" => array:1 [ "en" => "ROC curve IMC and early desaturators." ] ] 2 => array:8 [ "identificador" => "tbl0005" "etiqueta" => "Table 1" "tipo" => "MULTIMEDIATABLA" "mostrarFloat" => true "mostrarDisplay" => false "detalles" => array:1 [ 0 => array:3 [ "identificador" => "at1" "detalle" => "Table " "rol" => "short" ] ] "tabla" => array:2 [ "leyenda" => "Data are given as median (25th, 75th percentile) or mean±SD (mean±standard deviation); FEV1: forced expiratory volume in 1s." "tablatextoimagen" => array:1 [ 0 => array:2 [ "tabla" => array:1 [ 0 => """ <table border="0" frame="\n \t\t\t\t\tvoid\n \t\t\t\t" class=""><thead title="thead"><tr title="table-row"><th class="td" title="table-head " align="left" valign="top" scope="col" style="border-bottom: 2px solid black">Variables, units \t\t\t\t\t\t\n \t\t\t\t</th><th class="td" title="table-head " align="" valign="top" scope="col" style="border-bottom: 2px solid black"> \t\t\t\t\t\t\n \t\t\t\t</th></tr></thead><tbody title="tbody"><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Gender male (%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">79% \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Age, in years median (P25–P75) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">68 (61–76) \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Charlson index, median (P25–P75) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">5 (3–7) \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">BODE index, median (P25–P75) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">4 (2–5) \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">FEV1 (% predicted), mean±SD \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">46±18 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Initial SpO2 (%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">94±2 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">6-min walk distance (m), mean±SD \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">415±117 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Nadir SpO2 (%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">85±4 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Time to SpO2 <90%, median (P25–P75) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">1:34 (0:49–2:18) \t\t\t\t\t\t\n \t\t\t\t</td></tr></tbody></table> """ ] "imagenFichero" => array:1 [ 0 => "xTab1864235.png" ] ] ] ] "descripcion" => array:1 [ "en" => "Baseline characteristics of patients with exercise-induced desaturation." ] ] 3 => array:8 [ "identificador" => "tbl0010" "etiqueta" => "Table 2" "tipo" => "MULTIMEDIATABLA" "mostrarFloat" => true "mostrarDisplay" => false "detalles" => array:1 [ 0 => array:3 [ "identificador" => "at2" "detalle" => "Table " "rol" => "short" ] ] "tabla" => array:2 [ "leyenda" => "Data are given as median (25th, 75th percentile) or mean±SD (mean±standard deviation). Pearson Chi-squared, Mann–Whitney U, or Student t-test were applied. BMI: body mass index; FEV1: forced expiratory volume in 1s; FVC forced vital capacity; FEV1/FVC index; IC: inspiratory capacity; RV: residual volume; TLC: total lung capacity; DLCO: carbon monoxide diffusion capacity. mMRC: modified Medical Research Council scale." "tablatextoimagen" => array:1 [ 0 => array:2 [ "tabla" => array:1 [ 0 => """ <table border="0" frame="\n \t\t\t\t\tvoid\n \t\t\t\t" class=""><thead title="thead"><tr title="table-row"><th class="td-with-role" title="table-head ; entry_with_role_rowhead " align="left" valign="top" scope="col">Variables, units \t\t\t\t\t\t\n \t\t\t\t</th><th class="td" title="table-head " align="left" valign="top" scope="col">Early \t\t\t\t\t\t\n \t\t\t\t</th><th class="td" title="table-head " align="left" valign="top" scope="col">Non early \t\t\t\t\t\t\n \t\t\t\t</th><th class="td" title="table-head " align="left" valign="top" scope="col">p-value \t\t\t\t\t\t\n \t\t\t\t</th></tr><tr title="table-row"><th class="td" title="table-head " align="" valign="top" scope="col" style="border-bottom: 2px solid black"> \t\t\t\t\t\t\n \t\t\t\t</th><th class="td" title="table-head " align="left" valign="top" scope="col" style="border-bottom: 2px solid black">(n=32) \t\t\t\t\t\t\n \t\t\t\t</th><th class="td" title="table-head " align="left" valign="top" scope="col" style="border-bottom: 2px solid black">(n=74) \t\t\t\t\t\t\n \t\t\t\t</th><th class="td" title="table-head " align="" valign="top" scope="col" style="border-bottom: 2px solid black"> \t\t\t\t\t\t\n \t\t\t\t</th></tr></thead><tbody title="tbody"><tr title="table-row"><td class="td" title="table-entry " colspan="4" align="left" valign="top">Baseline</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Age, years, median (P25–P75) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">68 (63–76) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">68 (60–75) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.620 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">BMI (kg/m2), mean±SD \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">29±5 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">25±6 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.002 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Haemoglobin g/dl, mean±SD \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">14.2±2.0 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">14.4±1.7 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.667 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Smoking pack-year index, median (P25–P75) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">40 (10–68) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">40 (14–53) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.939 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Dyspnoea, mMRC scale, median (P25–P75) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">2 (1–3) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">2 (1–3) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.997 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">GOLD 2009 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="" valign="top"> \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="" valign="top"> \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.23 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Stage I (%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">6 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">7 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="" valign="top"> \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Stage II (%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">44 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">23 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="" valign="top"> \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Stage III (%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">37 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">51 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="" valign="top"> \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Stage IV (%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">13 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">19 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="" valign="top"> \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">GOLD 2017 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="" valign="top"> \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="" valign="top"> \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.986 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Stage A (%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">22 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">20 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="" valign="top"> \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Stage B (%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">41 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">39 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="" valign="top"> \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Stage C (%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">6 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">7 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="" valign="top"> \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Stage D (%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">31 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">35 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="" valign="top"> \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Charlson index, median (P25–P75) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">5 (4–7) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">5 (3–6) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.129 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">BODE index, median (P25–P75) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">4 (2–5) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">4 (2–5) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.913 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="table-entry " colspan="4" align="left" valign="top">Pulmonary function parameters</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">6-min walk distance (m), mean±SD \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">371±105 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">435±117 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.011 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Time to SpO2 (s) <90%, median (P25–P75) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">40 (35–46) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">110 (90–150) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top"><0.0001 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Initial SpO2 (%), mean±SD \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">93±1 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">94±2 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.002 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Nadir SpO2 (%), mean±SD \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">83±5 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">86±3 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.001 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Initial to nadir SpO2 (%), mean±SD \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">11±5 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">8±4 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.023 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">FEV1/FVC (% predicted), mean±SD \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">47±12 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">41±11 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.007 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">FEV1litres (% predicted), mean±SD \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">1.2±0.577 (48±17) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">1.2±0.654 (45±19) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.421 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">FVC litres (% predicted), mean±SD \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">2.5±0.673 (76±19) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">2.8±0.795 (81±19) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.196 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">IC litres (% predicted), mean±SD \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">2.2±0.703 (88±22) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">2.3±0.695 (87±23) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.913 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">RV/TLC, mean±SD \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">142±35 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">142±32 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.979 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">DLCO (% predicted), mean±SD \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">51±18 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">55±21 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.346 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="table-entry " colspan="4" align="left" valign="top">Comorbidities</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Hypertension (%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">59% \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">49% \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.310 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Dyslipidaemia (%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">59% \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">49% \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.310 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Diabetes mellitus (%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">28% \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">15% \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.109 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Ischaemic heart disease (%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">9% \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">15% \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.443 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Heart failure (%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">16% \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">9% \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.358 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Arrhythmia (%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">16% \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">15% \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">0.920 \t\t\t\t\t\t\n \t\t\t\t</td></tr></tbody></table> """ ] "imagenFichero" => array:1 [ 0 => "xTab1864234.png" ] ] ] ] "descripcion" => array:1 [ "en" => "Characteristic of early and non early desaturators patients." ] ] ] "bibliografia" => array:2 [ "titulo" => "References" "seccion" => array:1 [ 0 => array:2 [ "identificador" => "bibs0015" "bibliografiaReferencia" => array:17 [ 0 => array:3 [ "identificador" => "bib0090" "etiqueta" => "1" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Exertional hypoxemia in stable COPD is common and predicted by circulating proadrenomedullin" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:19 [ 0 => "D. Stolz" 1 => "W. Boersma" 2 => "F. Blasi" 3 => "R. Louis" 4 => "B. Milenkovic" 5 => "K. Kostikas" 6 => "J.G. Aerts" 7 => "G. Rohde" 8 => "A. Lacoma" 9 => "J. Rakic" 10 => "L. Boeck" 11 => "P. Castellotti" 12 => "A. Scherr" 13 => "A. Marin" 14 => "S. Hertel" 15 => "S. Giersdorf" 16 => "A. Torres" 17 => "T. Welte" 18 => "M. Tamm" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1378/chest.13-1967" "Revista" => array:6 [ "tituloSerie" => "Chest" "fecha" => "2014" "volumen" => "146" "paginaInicial" => "328" "paginaFinal" => "338" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/24722847" "web" => "Medline" ] ] ] ] ] ] ] ] 1 => array:3 [ "identificador" => "bib0095" "etiqueta" => "2" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Prevalence and prediction of exercise-induced oxygen desaturation in patients with chronic obstructive pulmonary disease" "autores" => array:1 [ 0 => array:2 [ "etal" => true "autores" => array:6 [ 0 => "A.J. Van Gestel" 1 => "C.F. Clarenbach" 2 => "A.C. Stowhas" 3 => "S. Teschler" 4 => "E.W. Russi" 5 => "H. Teschler" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1159/000332833" "Revista" => array:6 [ "tituloSerie" => "Respiration" "fecha" => "2012" "volumen" => "84" "paginaInicial" => "353" "paginaFinal" => "359" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/22269699" "web" => "Medline" ] ] ] ] ] ] ] ] 2 => array:3 [ "identificador" => "bib0100" "etiqueta" => "3" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Dynamic hyperinflation correlates with exertional oxygen desaturation in patients with chronic obstructive pulmonary disease" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:5 [ 0 => "M.A. Zafar" 1 => "W. Tsuang" 2 => "L. Lach" 3 => "W. Eschenbacher" 4 => "R.J. Panos" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1007/s00408-012-9443-3" "Revista" => array:6 [ "tituloSerie" => "Lung" "fecha" => "2013" "volumen" => "191" "paginaInicial" => "177" "paginaFinal" => "182" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/23283384" "web" => "Medline" ] ] ] ] ] ] ] ] 3 => array:3 [ "identificador" => "bib0105" "etiqueta" => "4" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Resting single-breath diffusing capacity as a screening test for exercise-induced hypoxemia" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "M.A. Kelley" 1 => "R.A. Panettieri Jr." 2 => "A.V. Krupinski" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "Am J Med" "fecha" => "1986" "volumen" => "80" "paginaInicial" => "807" "paginaFinal" => "812" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/3706368" "web" => "Medline" ] ] ] ] ] ] ] ] 4 => array:3 [ "identificador" => "bib0110" "etiqueta" => "5" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "The diffusing capacity as a predictor of arterial oxygen desaturation during exercise in patients with chronic obstructive pulmonary disease" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:4 [ 0 => "G.R. Owens" 1 => "R.M. Rogers" 2 => "B.E. Pennock" 3 => "D. Levin" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1056/NEJM198405103101903" "Revista" => array:6 [ "tituloSerie" => "N Engl J Med" "fecha" => "1984" "volumen" => "310" "paginaInicial" => "1218" "paginaFinal" => "1221" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/6709028" "web" => "Medline" ] ] ] ] ] ] ] ] 5 => array:3 [ "identificador" => "bib0115" "etiqueta" => "6" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Predicting walking-induced oxygen desaturations in COPD patients: a statistical model" "autores" => array:1 [ 0 => array:2 [ "etal" => true "autores" => array:6 [ 0 => "E. Crisafulli" 1 => "A. Iattoni" 2 => "E. Venturelli" 3 => "G. Siscaro" 4 => "C. Beneventi" 5 => "A. Cesario" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.4187/respcare.02321" "Revista" => array:6 [ "tituloSerie" => "Respir Care" "fecha" => "2013" "volumen" => "58" "paginaInicial" => "1495" "paginaFinal" => "1503" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/23362168" "web" => "Medline" ] ] ] ] ] ] ] ] 6 => array:3 [ "identificador" => "bib0120" "etiqueta" => "7" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "CT scores of emphysema and oxygen desaturation during low-grade exercise in patients with emphysema" "autores" => array:1 [ 0 => array:2 [ "etal" => true "autores" => array:6 [ 0 => "O. Taguchi" 1 => "E.C. Gabazza" 2 => "M. Yoshida" 3 => "H. Yasui" 4 => "T. Kobayashi" 5 => "H. Yuda" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "Acta Radiol" "fecha" => "2000" "volumen" => "41" "paginaInicial" => "196" "paginaFinal" => "197" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/10741797" "web" => "Medline" ] ] ] ] ] ] ] ] 7 => array:3 [ "identificador" => "bib0125" "etiqueta" => "8" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Determinants of exercise-induced oxygen desaturation including pulmonary emphysema in COPD: results from the ECLIPSE study" "autores" => array:1 [ 0 => array:2 [ "etal" => true "autores" => array:6 [ 0 => "V. Andrianopoulos" 1 => "B.R. Celli" 2 => "F.M. Franssen" 3 => "V.M. Pinto-Plata" 4 => "P.M. Calverley" 5 => "L.E. Vanfleteren" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1016/j.rmed.2016.08.023" "Revista" => array:6 [ "tituloSerie" => "Respir Med" "fecha" => "2016" "volumen" => "119" "paginaInicial" => "87" "paginaFinal" => "95" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/27692154" "web" => "Medline" ] ] ] ] ] ] ] ] 8 => array:3 [ "identificador" => "bib0130" "etiqueta" => "9" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Time to desaturation in the 6-min walking distance test predicts 24-hour oximetry in COPD with a PO2 between 60 and 70mmHg" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:6 [ 0 => "I. García-Talavera" 1 => "C.H. García" 2 => "C.C. Macario" 3 => "J.P. de Torres" 4 => "B.R. Celli" 5 => "A. Aguirre-Jaime" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1016/j.rmed.2008.02.004" "Revista" => array:6 [ "tituloSerie" => "Respir Med" "fecha" => "2008" "volumen" => "102" "paginaInicial" => "1026" "paginaFinal" => "1032" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/18343649" "web" => "Medline" ] ] ] ] ] ] ] ] 9 => array:3 [ "identificador" => "bib0135" "etiqueta" => "10" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Time to desaturation less than one minute predicts the need for long-term home oxygen therapy" "autores" => array:1 [ 0 => array:2 [ "etal" => true "autores" => array:6 [ 0 => "I. Garcia-Talavera" 1 => "A. Tauroni" 2 => "J.L. Trujillo" 3 => "R. Pitti" 4 => "L. Eiroa" 5 => "A. Aguirre-Jame" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.4187/respcare.01164" "Revista" => array:6 [ "tituloSerie" => "Respir Care" "fecha" => "2011" "volumen" => "56" "paginaInicial" => "1812" "paginaFinal" => "1817" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/21605486" "web" => "Medline" ] ] ] ] ] ] ] ] 10 => array:3 [ "identificador" => "bib0140" "etiqueta" => "11" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Consenso SEEDO 2007 para la evaluación del sobrepeso y la obesidad y el establecimiento de criterios de intervención terapéutica" "autores" => array:1 [ 0 => array:2 [ "etal" => true "autores" => array:6 [ 0 => "M.A. Rubio" 1 => "J. Salas-Salvadó" 2 => "M. Barbany" 3 => "B. Moreno" 4 => "J. Aranceta" 5 => "B. Bellido" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:4 [ "tituloSerie" => "Rev Esp Obes" "fecha" => "2007" "paginaInicial" => "7" "paginaFinal" => "48" ] ] ] ] ] ] 11 => array:3 [ "identificador" => "bib0145" "etiqueta" => "12" "referencia" => array:1 [ 0 => array:3 [ "comentario" => "<a class="elsevierStyleInterRef" target="_blank" id="intr0005" href="http://www.goldcopd.org/">http://www.goldcopd.org</a>" "contribucion" => array:1 [ 0 => array:1 [ "titulo" => "Global strategy for the diagnosis, management and prevention of COPD, global initiative for chronic obstructive lung disease (GOLD)" ] ] "host" => array:1 [ 0 => array:1 [ "Libro" => array:1 [ "fecha" => "2009" ] ] ] ] ] ] 12 => array:3 [ "identificador" => "bib0150" "etiqueta" => "13" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Guidelines for the six-minute walk test" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:1 [ 0 => "A.T.S. Statement:" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1164/ajrccm.166.1.at1102" "Revista" => array:6 [ "tituloSerie" => "Am J Respir Crit Care Med" "fecha" => "2002" "volumen" => "166" "paginaInicial" => "111" "paginaFinal" => "117" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/12091180" "web" => "Medline" ] ] ] ] ] ] ] ] 13 => array:3 [ "identificador" => "bib0155" "etiqueta" => "14" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "The connection between chronic obstructive pulmonary disease symptoms and hyperinflation and its impact on exercise and function" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:1 [ 0 => "C.B. Cooper" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1016/j.amjmed.2006.08.004" "Revista" => array:7 [ "tituloSerie" => "Am J Med" "fecha" => "2006" "volumen" => "119" "numero" => "Suppl 1" "paginaInicial" => "21" "paginaFinal" => "31" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/16996896" "web" => "Medline" ] ] ] ] ] ] ] ] 14 => array:3 [ "identificador" => "bib0160" "etiqueta" => "15" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Pulmonary characteristics in COPD and mechanisms of increased work of breathing" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "S.H. Loring" 1 => "M. Garcia-Jacques" 2 => "A. Malhotra" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1152/japplphysiol.00008.2009" "Revista" => array:6 [ "tituloSerie" => "J Appl Physiol" "fecha" => "1985 2009" "volumen" => "107" "paginaInicial" => "309" "paginaFinal" => "314" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/19359620" "web" => "Medline" ] ] ] ] ] ] ] ] 15 => array:3 [ "identificador" => "bib0165" "etiqueta" => "16" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Distance and oxygen desaturation in 6-min walk test predict prognosis in COPD patients" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:15 [ 0 => "N. Takigawa" 1 => "A. Tada" 2 => "R. Soda" 3 => "H. Date" 4 => "M. Yamashita" 5 => "S. Endo" 6 => "S. Takahashi" 7 => "N. Kawata" 8 => "T. Shibayama" 9 => "N. Hamada" 10 => "M. Sakaguchi" 11 => "A. Hirano" 12 => "G. Kimura" 13 => "C. Okada" 14 => "Takahashi K:" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1016/j.rmed.2006.06.017" "Revista" => array:6 [ "tituloSerie" => "Respir Med" "fecha" => "2007" "volumen" => "101" "paginaInicial" => "561" "paginaFinal" => "567" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/16899358" "web" => "Medline" ] ] ] ] ] ] ] ] 16 => array:3 [ "identificador" => "bib0170" "etiqueta" => "17" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Metabolic and inflammatory profile in obese patients with chronic obstructive pulmonary disease" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:7 [ 0 => "M. Poulain" 1 => "M. Doucet" 2 => "V. Drapeau" 3 => "G. Fournier" 4 => "A. Tremblay" 5 => "P. Poirier" 6 => "F. Maltais" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1177/1479972307087205" "Revista" => array:6 [ "tituloSerie" => "Chron Respir Dis" "fecha" => "2008" "volumen" => "5" "paginaInicial" => "35" "paginaFinal" => "41" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/18303100" "web" => "Medline" ] ] ] ] ] ] ] ] ] ] ] ] ] "idiomaDefecto" => "en" "url" => "/25310437/0000002400000005/v1_201810040621/S253104371830076X/v1_201810040621/en/main.assets" "Apartado" => array:4 [ "identificador" => "72878" "tipo" => "SECCION" "en" => array:2 [ "titulo" => "Original articles" "idiomaDefecto" => true ] "idiomaDefecto" => "en" ] "PDF" => "https://static.elsevier.es/multimedia/25310437/0000002400000005/v1_201810040621/S253104371830076X/v1_201810040621/en/main.pdf?idApp=UINPBA00004E&text.app=https://journalpulmonology.org/" "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/S253104371830076X?idApp=UINPBA00004E"]

Statistics

Original article

Clinical characteristics of COPD patients with early-onset desaturation in the 6-minute walk test

I. García-Talaveraa,

Corresponding author

igarmark@gmail.com

Corresponding author.

, J.M. Figueira-Gonçalvesa, N. Gurbania, L. Pérez-Méndezb,c, A. Pedrero-Garcíab

a Pneumology Service and Thoracic Surgery, University Hospital Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain

b Division of Clinical Epidemiology and Biostatistics, Research Unit, University Hospital Nuestra Señora de Candelaria, and Primary Care Management, Santa Cruz de Tenerife, Spain

c Networked Biomedical Research Centre (CIBER) of Respiratory Diseases, Carlos III Health Institute, Madrid, Spain

Read

5085

Times
was read the article

2238

Total PDF

2847

Total HTML

Share statistics

 array:24 [
  "pii" => "S253104371830076X"
  "issn" => "25310437"
  "doi" => "10.1016/j.pulmoe.2018.04.007"
  "estado" => "S300"
  "fechaPublicacion" => "2018-09-01"
  "aid" => "35"
  "copyright" => "Sociedade Portuguesa de Pneumologia"
  "copyrightAnyo" => "2018"
  "documento" => "article"
  "crossmark" => 1
  "licencia" => "http://creativecommons.org/licenses/by-nc-nd/4.0/"
  "subdocumento" => "fla"
  "cita" => "Pulmonol. 2018;24:275-9"
  "abierto" => array:3 [
    "ES" => true
    "ES2" => true
    "LATM" => true
  ]
  "gratuito" => true
  "lecturas" => array:2 [
    "total" => 1296
    "formatos" => array:3 [
      "EPUB" => 172
      "HTML" => 698
      "PDF" => 426
    ]
  ]
  "itemSiguiente" => array:19 [
    "pii" => "S2531043718300461"
    "issn" => "25310437"
    "doi" => "10.1016/j.pulmoe.2018.02.007"
    "estado" => "S300"
    "fechaPublicacion" => "2018-09-01"
    "aid" => "20"
    "copyright" => "Sociedade Portuguesa de Pneumologia"
    "documento" => "article"
    "crossmark" => 1
    "licencia" => "http://creativecommons.org/licenses/by-nc-nd/4.0/"
    "subdocumento" => "fla"
    "cita" => "Pulmonol. 2018;24:280-8"
    "abierto" => array:3 [
      "ES" => true
      "ES2" => true
      "LATM" => true
    ]
    "gratuito" => true
    "lecturas" => array:2 [
      "total" => 1593
      "formatos" => array:3 [
        "EPUB" => 188
        "HTML" => 953
        "PDF" => 452
      ]
    ]
    "en" => array:12 [
      "idiomaDefecto" => true
      "cabecera" => "<span class="elsevierStyleTextfn">Original article</span>"
      "titulo" => "Chronic respiratory failure in patients with chronic obstructive pulmonary disease under home noninvasive ventilation&#58; Real-life study"
      "tienePdf" => "en"
      "tieneTextoCompleto" => "en"
      "tieneResumen" => "en"
      "paginas" => array:1 [
        0 => array:2 [
          "paginaInicial" => "280"
          "paginaFinal" => "288"
        ]
      ]
      "contieneResumen" => array:1 [
        "en" => true
      ]
      "contieneTextoCompleto" => array:1 [
        "en" => true
      ]
      "contienePdf" => array:1 [
        "en" => true
      ]
      "resumenGrafico" => array:2 [
        "original" => 0
        "multimedia" => array:7 [
          "identificador" => "fig0005"
          "etiqueta" => "Figure 1"
          "tipo" => "MULTIMEDIAFIGURA"
          "mostrarFloat" => true
          "mostrarDisplay" => false
          "figura" => array:1 [
            0 => array:4 [
              "imagen" => "gr1.jpeg"
              "Alto" => 1104
              "Ancho" => 2410
              "Tamanyo" => 95703
            ]
          ]
          "descripcion" => array:1 [
            "en" => "<p id="spar0005" class="elsevierStyleSimplePara elsevierViewall">Clinical conditions causing CHRF in the 334 patients treated with home NIV at the noninvasive respiratory care unit of Hospital Pulido Valente between August 2011 and July 2014&#46; COPD&#44; chronic obstructive pulmonary disease&#59; OHS&#44; obesity hypoventilation syndrome&#59; NMD&#44; neuromuscular disease&#46;</p>"
          ]
        ]
      ]
      "autores" => array:1 [
        0 => array:2 [
          "autoresLista" => "V&#46; Dur&#227;o, M&#46; Grafino, P&#46; Pamplona"
          "autores" => array:3 [
            0 => array:2 [
              "nombre" => "V&#46;"
              "apellidos" => "Dur&#227;o"
            ]
            1 => array:2 [
              "nombre" => "M&#46;"
              "apellidos" => "Grafino"
            ]
            2 => array:2 [
              "nombre" => "P&#46;"
              "apellidos" => "Pamplona"
            ]
          ]
        ]
      ]
    ]
    "idiomaDefecto" => "en"
    "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/S2531043718300461?idApp=UINPBA00004E"
    "url" => "/25310437/0000002400000005/v1_201810040621/S2531043718300461/v1_201810040621/en/main.assets"
  ]
  "itemAnterior" => array:18 [
    "pii" => "S2531043718301302"
    "issn" => "25310437"
    "doi" => "10.1016/j.pulmoe.2018.09.002"
    "estado" => "S300"
    "fechaPublicacion" => "2018-09-01"
    "aid" => "1310"
    "documento" => "simple-article"
    "crossmark" => 1
    "licencia" => "http://creativecommons.org/licenses/by-nc-nd/4.0/"
    "subdocumento" => "edi"
    "cita" => "Pulmonol. 2018;24:273-4"
    "abierto" => array:3 [
      "ES" => true
      "ES2" => true
      "LATM" => true
    ]
    "gratuito" => true
    "lecturas" => array:2 [
      "total" => 1457
      "formatos" => array:3 [
        "EPUB" => 158
        "HTML" => 916
        "PDF" => 383
      ]
    ]
    "en" => array:9 [
      "idiomaDefecto" => true
      "titulo" => "It&#39;s been a hard day&#39;s night&#8230;But it was worth every minute"
      "tienePdf" => "en"
      "tieneTextoCompleto" => "en"
      "paginas" => array:1 [
        0 => array:2 [
          "paginaInicial" => "273"
          "paginaFinal" => "274"
        ]
      ]
      "contieneTextoCompleto" => array:1 [
        "en" => true
      ]
      "contienePdf" => array:1 [
        "en" => true
      ]
      "resumenGrafico" => array:2 [
        "original" => 0
        "multimedia" => array:7 [
          "identificador" => "fig0005"
          "etiqueta" => "Fig&#46; 1"
          "tipo" => "MULTIMEDIAFIGURA"
          "mostrarFloat" => true
          "mostrarDisplay" => false
          "figura" => array:1 [
            0 => array:4 [
              "imagen" => "gr1.jpeg"
              "Alto" => 806
              "Ancho" => 1549
              "Tamanyo" => 52738
            ]
          ]
          "descripcion" => array:1 [
            "en" => "<p id="spar0005" class="elsevierStyleSimplePara elsevierViewall">RPP Impact Factor evolution in the last five years&#46;</p>"
          ]
        ]
      ]
      "autores" => array:1 [
        0 => array:2 [
          "autoresLista" => "Ant&#243;nio Morais"
          "autores" => array:1 [
            0 => array:2 [
              "nombre" => "Ant&#243;nio"
              "apellidos" => "Morais"
            ]
          ]
        ]
      ]
    ]
    "idiomaDefecto" => "en"
    "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/S2531043718301302?idApp=UINPBA00004E"
    "url" => "/25310437/0000002400000005/v1_201810040621/S2531043718301302/v1_201810040621/en/main.assets"
  ]
  "en" => array:18 [
    "idiomaDefecto" => true
    "cabecera" => "<span class="elsevierStyleTextfn">Original article</span>"
    "titulo" => "Clinical characteristics of COPD patients with early-onset desaturation in the 6-minute walk test"
    "tieneTextoCompleto" => true
    "paginas" => array:1 [
      0 => array:2 [
        "paginaInicial" => "275"
        "paginaFinal" => "279"
      ]
    ]
    "autores" => array:1 [
      0 => array:4 [
        "autoresLista" => "I&#46; Garc&#237;a-Talavera, J&#46;M&#46; Figueira-Gon&#231;alves, N&#46; Gurbani, L&#46; P&#233;rez-M&#233;ndez, A&#46; Pedrero-Garc&#237;a"
        "autores" => array:5 [
          0 => array:4 [
            "nombre" => "I&#46;"
            "apellidos" => "Garc&#237;a-Talavera"
            "email" => array:1 [
              0 => "igarmark&#64;gmail&#46;com"
            ]
            "referencia" => array:2 [
              0 => array:2 [
                "etiqueta" => "<span class="elsevierStyleSup">a</span>"
                "identificador" => "aff0005"
              ]
              1 => array:2 [
                "etiqueta" => "<span class="elsevierStyleSup">&#42;</span>"
                "identificador" => "cor0005"
              ]
            ]
          ]
          1 => array:3 [
            "nombre" => "J&#46;M&#46;"
            "apellidos" => "Figueira-Gon&#231;alves"
            "referencia" => array:1 [
              0 => array:2 [
                "etiqueta" => "<span class="elsevierStyleSup">a</span>"
                "identificador" => "aff0005"
              ]
            ]
          ]
          2 => array:3 [
            "nombre" => "N&#46;"
            "apellidos" => "Gurbani"
            "referencia" => array:1 [
              0 => array:2 [
                "etiqueta" => "<span class="elsevierStyleSup">a</span>"
                "identificador" => "aff0005"
              ]
            ]
          ]
          3 => array:3 [
            "nombre" => "L&#46;"
            "apellidos" => "P&#233;rez-M&#233;ndez"
            "referencia" => array:2 [
              0 => array:2 [
                "etiqueta" => "<span class="elsevierStyleSup">b</span>"
                "identificador" => "aff0010"
              ]
              1 => array:2 [
                "etiqueta" => "<span class="elsevierStyleSup">c</span>"
                "identificador" => "aff0015"
              ]
            ]
          ]
          4 => array:3 [
            "nombre" => "A&#46;"
            "apellidos" => "Pedrero-Garc&#237;a"
            "referencia" => array:1 [
              0 => array:2 [
                "etiqueta" => "<span class="elsevierStyleSup">b</span>"
                "identificador" => "aff0010"
              ]
            ]
          ]
        ]
        "afiliaciones" => array:3 [
          0 => array:3 [
            "entidad" => "Pneumology Service and Thoracic Surgery&#44; University Hospital Nuestra Se&#241;ora de Candelaria&#44; Santa Cruz de Tenerife&#44; Spain"
            "etiqueta" => "a"
            "identificador" => "aff0005"
          ]
          1 => array:3 [
            "entidad" => "Division of Clinical Epidemiology and Biostatistics&#44; Research Unit&#44; University Hospital Nuestra Se&#241;ora de Candelaria&#44; and Primary Care Management&#44; Santa Cruz de Tenerife&#44; Spain"
            "etiqueta" => "b"
            "identificador" => "aff0010"
          ]
          2 => array:3 [
            "entidad" => "Networked Biomedical Research Centre &#40;CIBER&#41; of Respiratory Diseases&#44; Carlos III Health Institute&#44; Madrid&#44; Spain"
            "etiqueta" => "c"
            "identificador" => "aff0015"
          ]
        ]
        "correspondencia" => array:1 [
          0 => array:3 [
            "identificador" => "cor0005"
            "etiqueta" => "&#8270;"
            "correspondencia" => "Corresponding author&#46;"
          ]
        ]
      ]
    ]
    "resumenGrafico" => array:2 [
      "original" => 0
      "multimedia" => array:7 [
        "identificador" => "fig0005"
        "etiqueta" => "Figure 1"
        "tipo" => "MULTIMEDIAFIGURA"
        "mostrarFloat" => true
        "mostrarDisplay" => false
        "figura" => array:1 [
          0 => array:4 [
            "imagen" => "gr1.jpeg"
            "Alto" => 1271
            "Ancho" => 1604
            "Tamanyo" => 68461
          ]
        ]
        "descripcion" => array:1 [
          "en" => "<p id="spar0025" class="elsevierStyleSimplePara elsevierViewall">BMI in early and non early desaturators patients&#46;</p>"
        ]
      ]
    ]
    "textoCompleto" => "<span class="elsevierStyleSections"><span id="sec0005" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0035">Introduction</span><p id="par0005" class="elsevierStylePara elsevierViewall">Exercise-induced oxygen desaturation &#40;EID&#41; occurs in up to 20&#37; of the patients with chronic obstructive pulmonary disease &#40;COPD&#41;&#46;<a class="elsevierStyleCrossRef" href="#bib0090"><span class="elsevierStyleSup">1</span></a> However&#44; despite being a relatively frequent condition&#44; its definition has not yet been agreed upon&#46;<a class="elsevierStyleCrossRefs" href="#bib0095"><span class="elsevierStyleSup">2&#8211;4</span></a> The most widely accepted criterion in common practice comprises a drop in oxygen saturation &#40;SatO2&#41; of more than 4&#37; with a nadir of at least 88&#37;&#46; Although the pathophysiology of EID is a matter of debate&#44; aspects such as the severity of airflow obstruction&#44; a low CO diffusion capacity &#40;DLCO&#41;&#44; a high degree of emphysema&#44; obesity&#44; and a SatO2 at rest &#8804;93&#37; have been related to it&#46;<a class="elsevierStyleCrossRefs" href="#bib0110"><span class="elsevierStyleSup">5&#8211;8</span></a></p><p id="par0010" class="elsevierStylePara elsevierViewall">Studies carried out by our group show that the decrease in the SatO2 curve during the 6-minute walk test &#40;6MWT&#41; has prognostic implications&#46; Patients with such an event before the end of the first minute of the test&#44; termed &#8216;early desaturators&#8217; &#40;EDs&#41;&#44; had a high probability of also experiencing them during their daily life activities and of additionally developing hypoxaemic respiratory failure at rest within the subsequent 5 years compared to subjects who desaturated after 3<span class="elsevierStyleHsp" style=""></span>min&#46;<a class="elsevierStyleCrossRefs" href="#bib0130"><span class="elsevierStyleSup">9&#44;10</span></a> Given the occurrence of the two desaturation profiles in patients with the same disease&#44; the assessment of possible differential factors associated with this behaviour is imperative&#46;</p><p id="par0015" class="elsevierStylePara elsevierViewall">The purpose of this study was to characterise COPD patients with early desaturation versus non-early desaturation as well as determine potential markers that point to events of EID before the end of the first minute&#46;</p></span><span id="sec0010" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0040">Methods</span><span id="sec0015" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0045">Patients</span><p id="par0020" class="elsevierStylePara elsevierViewall">From a pool of 163 patients with COPD and exercise desaturation on the 6<span class="elsevierStyleHsp" style=""></span>min walking test registered on our laboratory data base&#44; 57 were not selected because they had interstitial disease&#44; severe cardiac disease&#44; domiciliary oxygentherapy&#46; Then we conducted a cross-sectional study in 106 COPD &#40;<a class="elsevierStyleCrossRef" href="#tbl0005">Table 1</a>&#41; patients&#44; normoxaemic at rest but experiencing EID&#46; The inclusion criteria were&#58; aged over 40 years&#44; active or former smoker with a pack-year index &#40;PYI&#41; &#62;10 and a post-bronchodilator ratio of forced expiratory volume in one second &#40;FEV<span class="elsevierStyleInf">1</span>&#41;&#47;forced vital capacity &#40;FVC&#41; &#60;70&#37;&#44; in addition to a basal SatO2 &#62;90&#37;&#46; Patients with SatO2 at rest &#8804;90&#37; or who were not able to correctly perform the 6MWT were excluded&#46;</p><elsevierMultimedia ident="tbl0005"></elsevierMultimedia></span><span id="sec0020" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0050">Measurements</span><p id="par0025" class="elsevierStylePara elsevierViewall">The following data from this descriptive&#44; observational study was collected retrospectively from computerised medical records&#58; age&#59; sex&#59; smoking history &#40;active smokers if they had smoked at least one cigarette in the course of the foregoing 6 months&#59; former smokers if they had maintained continuous abstinence for at least 6 months&#41;&#59; smoking intensity by means of the PYI &#40;defined as the number of packs of cigarettes smoked per day multiplied by the number of years as a smoker and divided by 20&#41;&#59; body mass index &#40;BMI&#41; following the SEEDO<a class="elsevierStyleCrossRef" href="#bib0140"><span class="elsevierStyleSup">11</span></a> criteria&#59; dyspnoea &#40;modified Medical Research Council &#91;mMRC&#93; scale&#41;&#59; comorbidity &#40;assessed by means of the Charlson index&#41;&#59; BODE index&#59; the associated cardiovascular risk factors arterial hypertension Type 2 diabetes mellitus&#44; dyslipidaemia&#44; and obesity&#59; and finally cardiovascular diseases such as arrhythmia&#44; ischaemic heart disease&#44; and congestive heart failure&#46; In addition&#44; we recorded the results of the following pulmonary function tests&#58; FEV<span class="elsevierStyleInf">1</span>&#44; FVC&#44; FEV<span class="elsevierStyleInf">1</span>&#47;FVC&#44; inspiratory capacity &#40;IC&#41;&#44; residual volume&#44; total lung capacity&#44; and lung diffusion capacity for CO &#40;DLCO&#41;&#46; Patients were stratified according to the four degrees of airflow obstruction collected in the 2009 GOLD &#40;Global Initiative for Chronic Obstructive Lung Disease guidelines&#46;<a class="elsevierStyleCrossRef" href="#bib0145"><span class="elsevierStyleSup">12</span></a></p><p id="par0030" class="elsevierStylePara elsevierViewall">The 6MWT was performed in a 30-m long corridor following the ATS&#47;ERS<a class="elsevierStyleCrossRef" href="#bib0150"><span class="elsevierStyleSup">13</span></a> protocol&#46; Briefly&#44; all tests were performed without supplemental oxygen and supervised by two observers&#44; who instructed the patients to walk 6<span class="elsevierStyleHsp" style=""></span>min along the corridor to complete as many metres as possible&#46; Patients were allowed to stop if they had dyspnoea and resume walking when the symptoms had disappeared&#46; The following variables were collected&#58; initial and minimum SatO2&#44; metres walked during the 6<span class="elsevierStyleHsp" style=""></span>min of the test&#44; as well as the point in time at which the SatO2 had come to the threshold of 90&#37; &#40;T90&#41;&#46; EID was defined as a 4&#37; drop in SatO2 from baseline&#44; reaching a minimum of 88&#37; or lower&#46; Patients who desaturated during exercise within the first minute of the 6MWT were defined EDs and those who did so at a later point in time as non-early desaturators &#40;NEDs&#41;&#46;</p></span><span id="sec0025" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0055">Statistical analysis</span><p id="par0035" class="elsevierStylePara elsevierViewall">Data were summarised as frequencies for categorical variables&#44; as mean<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>SD for normally distributed data&#44; and median &#40;25th&#8211;75th percentile&#41; for non-normally distributed outcome data&#46; Comparisons between the groups ED and NED were explored using Pearson Chi-squared test&#44; the Mann&#8211;Whitney <span class="elsevierStyleItalic">U</span>-test&#44; and Student <span class="elsevierStyleItalic">t</span>-test as appropriate&#46;</p><p id="par0040" class="elsevierStylePara elsevierViewall">Differential patient characteristics before performing the 6MWT test were BMI and initial pulse oximetre saturation &#40;SpO2&#41; &#40;<a class="elsevierStyleCrossRef" href="#tbl0005">Table 1</a>&#41;&#46; We applied multivariate logistic regression analysis&#44; adjusted by initial SpO2&#44; to determine the association between BMI and ED&#46; Finally&#44; to evaluate the discriminative capacity of the <span class="elsevierStyleItalic">continuous BMI scale</span> as a possible marker of ED&#44; a receiver operator characteristic &#40;ROC&#41; curve was generated and the area underneath the curve &#40;AUC&#41; calculated&#46;</p><p id="par0045" class="elsevierStylePara elsevierViewall">The sample size &#40;<span class="elsevierStyleItalic">n</span><span class="elsevierStyleHsp" style=""></span>&#61;<span class="elsevierStyleHsp" style=""></span>106&#41; was estimated based on a frequency-of-outcomes factor of at least 20&#37; of ED in the population with a confidence interval of 95&#37; and a beta error of 20&#37;&#46; The significance level was established as <span class="elsevierStyleItalic">p</span><span class="elsevierStyleHsp" style=""></span>&#60;<span class="elsevierStyleHsp" style=""></span>0&#46;05&#46; All analyses were performed with the SPSS&#47;PC statistical programme &#40;version 21&#46;0 for Windows&#59; SPSS&#44; Inc&#46;&#44; Chicago&#44; IL&#44; USA&#41;&#46; The study was approved by the ethics committee of the University Hospital Nuestra Se&#241;ora de Candelaria &#40;Tenerife&#44; Spain&#41;&#46;</p></span></span><span id="sec0030" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0060">Results</span><span id="sec0035" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0065">Subject characteristics</span><p id="par0050" class="elsevierStylePara elsevierViewall">A total of 106 patients were included in this study&#44; all of them had COPD diagnosed and were staged as per GOLD guidelines&#46; All patients desaturated either before or after the first minute of the 6MWT&#46; The patients&#8217; characteristics are reflected in <a class="elsevierStyleCrossRef" href="#tbl0005">Table 1</a>&#46; Most of them were men &#40;ratio 4&#47;1&#41; with a median age of 68 years and a predicted FEV<span class="elsevierStyleInf">1</span> of 46&#37;&#46; The baseline oxygen saturation was above 90&#37;&#46; 93&#37; of patients had moderate to severe airflow limitation and a high risk measured by BODE scale&#46; Thirty two subjects &#40;30&#37;&#41; were classified as EDs&#46;</p></span><span id="sec0040" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0070">Differences between ED and NED</span><p id="par0055" class="elsevierStylePara elsevierViewall"><a class="elsevierStyleCrossRef" href="#tbl0010">Table 2</a> compares the baseline characteristics of the ED versus the NED group&#44; which resembled each other in age&#44; GOLD stages with most of the subjects suffering from moderate to severe obstruction&#44; as well as BODE and Charlson index&#46; Hypertension and dyslipidaemia were the most frequent comorbidities in general&#59; no differences were observed in mortality&#46; When performing the 6MWT&#44; differential BMI values became evident&#46; The mean BMI was higher in ED than in NED patients with an inverse relation as to the categorical BMI levels &#60;25&#44; 25&#8211;29&#44; and &#8805;30 &#40;<span class="elsevierStyleItalic">p</span> for trends<span class="elsevierStyleHsp" style=""></span>&#61;<span class="elsevierStyleHsp" style=""></span>0&#46;011&#59; <a class="elsevierStyleCrossRef" href="#fig0005">Fig&#46; 1</a>&#41;&#46;</p><elsevierMultimedia ident="tbl0010"></elsevierMultimedia><elsevierMultimedia ident="fig0005"></elsevierMultimedia><p id="par0060" class="elsevierStylePara elsevierViewall">Although we observed a significantly lower mean initial SpO2&#44; this was clinically not relevant&#46; Therefore its influence was adjusted in the multivariate analysis using the quartil of initial SpO2&#46; The probability of ED during exercise increased by 1&#46;79 &#40;OR<span class="elsevierStyleInf">ajusted</span>&#41; in overweight and obese patients &#40;95&#37; CI 1&#46;12&#8211;2&#46;86&#59; <span class="elsevierStyleItalic">p</span><span class="elsevierStyleHsp" style=""></span>&#61;<span class="elsevierStyleHsp" style=""></span>0&#46;015&#41;&#46;</p><p id="par0065" class="elsevierStylePara elsevierViewall">Finally&#44; the area under the curves showed the discriminative capacity of the continuous scale for BMI analysis&#58; AUC<span class="elsevierStyleHsp" style=""></span>&#61;<span class="elsevierStyleHsp" style=""></span>70&#37; &#40;95&#37; CI&#44; 60&#8211;81&#37;&#59; <span class="elsevierStyleItalic">p</span><span class="elsevierStyleHsp" style=""></span>&#61;<span class="elsevierStyleHsp" style=""></span>0&#46;001&#59; <a class="elsevierStyleCrossRef" href="#fig0010">Fig&#46; 2</a>&#41;&#46;</p><elsevierMultimedia ident="fig0010"></elsevierMultimedia><p id="par0070" class="elsevierStylePara elsevierViewall"><a class="elsevierStyleCrossRef" href="#tbl0010">Table 2</a> also reflects the distribution of clinical&#44; functional parameters and lung function&#46; We did not detect any differences in static functional respiratory parameters except that EDs had a lower FEV<span class="elsevierStyleInf">1</span>&#47;FVC index than NEDs&#46; ED patients also walked 64<span class="elsevierStyleHsp" style=""></span>m less &#40;mean&#41; in the 6MWT &#40;<span class="elsevierStyleItalic">p</span><span class="elsevierStyleHsp" style=""></span>&#61;<span class="elsevierStyleHsp" style=""></span>0&#46;011&#41;&#44; and they desaturated more deeply &#40;10&#46;7<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>4&#46;6&#37; versus 8&#46;6<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>3&#46;5&#37;&#59; <span class="elsevierStyleItalic">p</span><span class="elsevierStyleHsp" style=""></span>&#61;<span class="elsevierStyleHsp" style=""></span>0&#46;025&#41;&#46;</p></span></span><span id="sec0045" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0075">Discussion</span><p id="par0075" class="elsevierStylePara elsevierViewall">EID is the result of a mismatch between ventilation and perfusion during physical effort&#46; Airflow limitation and loss of lung elasticity lead to increased air trapping and dynamic hyperinflation&#44; increasing patient inspiratory work and thereby increasing oxygen consumption in COPD patients&#46;<a class="elsevierStyleCrossRefs" href="#bib0100"><span class="elsevierStyleSup">3&#44;13&#44;14</span></a> Until a few years ago&#44; this phenomenon observed during the 6MWT&#44; did not provide any further information than that of the change in SatO2&#46; It was considered a mere curiosity&#44; which appeared in a group of COPD patients but did not translate into a change in medical attitude&#44; perception of poor prognosis or treatment modification&#46; Takigawa et al&#46;<a class="elsevierStyleCrossRef" href="#bib0160"><span class="elsevierStyleSup">15</span></a> demonstrated that&#44; in addition to the distance walked in the 6MWT&#44; the variation in SatO2 also had prognostic implications&#46; Later&#44; the phenomenon came to be no longer regarded as an unimportant fact&#44; but one to be taken into account together with parameters such as the metres covered in the 6MWT&#44; the FEV<span class="elsevierStyleInf">1</span>&#44; and the oxygen partial pressure in blood&#46; A few years later&#44; these findings were corroborated by the ECLIPSE<a class="elsevierStyleCrossRef" href="#bib0125"><span class="elsevierStyleSup">8</span></a> group&#44; who demonstrated that both desaturation and the frequency of stops during the walk test were prognostic factors&#46; However&#44; the possible different types of desaturation have not yet been well characterised&#44; neither in terms of their definition&#44; which remains ambiguous&#44; nor addressing the different forms as to the distinction between basal and minimal desaturation&#44; its quality and nature&#46; We defined a category&#44; termed ED&#44; to differentiate it from late and intermediate desaturation&#46; This was the result of a study where we compared desaturation in two different settings&#44; the 6MWT and daily life activities&#46; Only the patients who desaturated within the first minute of the test also did so outside the hospital in their daily activities&#44; something that was not true of those who desaturated only after 3&#46;5<span class="elsevierStyleHsp" style=""></span>min&#46;<a class="elsevierStyleCrossRef" href="#bib0130"><span class="elsevierStyleSup">9</span></a> Therefore&#44; early desaturation in the 6MWT is a relevant aspect&#44; because it implies desaturation during everyday activities and under low levels of physical strain&#46; In addition to this aspect&#44; the ED patient group is more likely to develop respiratory insufficiency over time than the NEDs&#46; Hence&#44; the elapsed time to desaturation in the 6MWT is a useful variable&#44; which provides information of clinical interest&#46; Additional potential markers to consider are the depth and persistence of desaturation&#46; Of note&#44; early desaturation also tends to be deep&#59; according to our observations in this study&#44; the nadir is very low&#46; We were interested in defining a profile of patients who desaturate early and analyse clinical and functional characteristics to identify potential differential parameters between EDs and patients who desaturate after the first minute of the 6MWT&#46; Like other authors&#44;<a class="elsevierStyleCrossRefs" href="#bib0095"><span class="elsevierStyleSup">2&#44;6</span></a> we found that desaturation is typical of patients with low FEV<span class="elsevierStyleInf">1</span> and relatively low baseline DLCO and SatO2 values&#46; But it remained to be determined whether there was a defined profile for ED patients&#46; We did not observe differences in either age or FEV<span class="elsevierStyleInf">1</span> values&#44; and although DLCO was somewhat lower in EDs&#44; this was not statistically significant&#46; From a functional point of view&#44; basal SatO2 and the distance walked in the 6MWT were significantly lower in EDs compared to the NED group&#44; and it should be emphasised that the desaturation in the ED group was more profound&#44; which may be considered as another feature of severity&#46; However&#44; BMI was the most outstanding parameter in the ED group&#46; These patients were more obese&#44; although this was not associated with comorbidities such as ischaemic heart disease&#44; cardiac arrhythmia&#44; or AHT&#46; Recently&#44; Andrianopoulos et al&#46;<a class="elsevierStyleCrossRef" href="#bib0125"><span class="elsevierStyleSup">8</span></a> analysed patients from the ECLIPSE cohort and described obesity as a factor involved in EID &#40;OR 1&#46;57&#44; 95&#37; CI 1&#46;15&#8211;2&#46;14&#41; along with additional parameters&#44; such as a high degree of airflow obstruction and low DLCO values&#46; While obesity has been linked to low baseline SatO2 and EID&#44;<a class="elsevierStyleCrossRefs" href="#bib0125"><span class="elsevierStyleSup">8&#44;16</span></a> our study adds that this feature appears to be limited to ED COPD patients&#46;</p><p id="par0080" class="elsevierStylePara elsevierViewall">COPD patients may exhibit very diverse characteristics&#44; which depend on the association with other conditions such as bronchial asthma&#44; sleep apnoea&#44; and fibrosis&#46; EID occurs preferentially in severe patients with low DLCO values&#59; although&#44; unexpectedly&#44; it is not observed in lean but in obese patients&#46; Early desaturation&#44; which we think is of great importance because it translates to increased severity&#44; is preferentially observed in subjects with a BMI &#8805;30&#46; Alterations in respiratory mechanics or higher levels of proinflammatory cytokines such as leptin may possibly explain this phenomenon&#46;<a class="elsevierStyleCrossRef" href="#bib0170"><span class="elsevierStyleSup">17</span></a></p><p id="par0085" class="elsevierStylePara elsevierViewall">There are some limitations&#59; the study is retrospective&#44; the number of patients is not very high&#44; the proportion of women is very low&#44; we did not select non-smoker patients and the study only took place in hospital&#46;</p><p id="par0090" class="elsevierStylePara elsevierViewall">In summary&#44; we would like to draw special attention to COPD patients with severe to very severe obstruction&#44; low DLCO&#44; and overt obesity&#44; because they may experience early and profound desaturation during exercise and&#44; together with the obesity&#44; suffer from very harmful long-term effects&#46;</p></span><span id="sec0050" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0080">Funding</span><p id="par0095" class="elsevierStylePara elsevierViewall"><span class="elsevierStyleGrantSponsor" id="gs1">Menarini SA Corp Foundation</span>&#46;</p></span><span id="sec0055" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0085">Conflicts of interest</span><p id="par0100" class="elsevierStylePara elsevierViewall">The authors have no conflicts of interest to declare&#46;</p></span></span>"
    "textoCompletoSecciones" => array:1 [
      "secciones" => array:9 [
        0 => array:3 [
          "identificador" => "xres1090337"
          "titulo" => "Abstract"
          "secciones" => array:4 [
            0 => array:2 [
              "identificador" => "abst0005"
              "titulo" => "Background"
            ]
            1 => array:2 [
              "identificador" => "abst0010"
              "titulo" => "Methods"
            ]
            2 => array:2 [
              "identificador" => "abst0015"
              "titulo" => "Results"
            ]
            3 => array:2 [
              "identificador" => "abst0020"
              "titulo" => "Conclusion"
            ]
          ]
        ]
        1 => array:2 [
          "identificador" => "xpalclavsec1033630"
          "titulo" => "Keywords"
        ]
        2 => array:2 [
          "identificador" => "sec0005"
          "titulo" => "Introduction"
        ]
        3 => array:3 [
          "identificador" => "sec0010"
          "titulo" => "Methods"
          "secciones" => array:3 [
            0 => array:2 [
              "identificador" => "sec0015"
              "titulo" => "Patients"
            ]
            1 => array:2 [
              "identificador" => "sec0020"
              "titulo" => "Measurements"
            ]
            2 => array:2 [
              "identificador" => "sec0025"
              "titulo" => "Statistical analysis"
            ]
          ]
        ]
        4 => array:3 [
          "identificador" => "sec0030"
          "titulo" => "Results"
          "secciones" => array:2 [
            0 => array:2 [
              "identificador" => "sec0035"
              "titulo" => "Subject characteristics"
            ]
            1 => array:2 [
              "identificador" => "sec0040"
              "titulo" => "Differences between ED and NED"
            ]
          ]
        ]
        5 => array:2 [
          "identificador" => "sec0045"
          "titulo" => "Discussion"
        ]
        6 => array:2 [
          "identificador" => "sec0050"
          "titulo" => "Funding"
        ]
        7 => array:2 [
          "identificador" => "sec0055"
          "titulo" => "Conflicts of interest"
        ]
        8 => array:1 [
          "titulo" => "References"
        ]
      ]
    ]
    "pdfFichero" => "main.pdf"
    "tienePdf" => true
    "fechaRecibido" => "2017-09-15"
    "fechaAceptado" => "2018-04-07"
    "PalabrasClave" => array:1 [
      "en" => array:1 [
        0 => array:4 [
          "clase" => "keyword"
          "titulo" => "Keywords"
          "identificador" => "xpalclavsec1033630"
          "palabras" => array:3 [
            0 => "COPD"
            1 => "Exercise desaturation"
            2 => "6 min walking test"
          ]
        ]
      ]
    ]
    "tieneResumen" => true
    "resumen" => array:1 [
      "en" => array:3 [
        "titulo" => "Abstract"
        "resumen" => "<span id="abst0005" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0010">Background</span><p id="spar0005" class="elsevierStyleSimplePara elsevierViewall">Exercise-induced desaturation in chronic obstructive pulmonary disease &#40;COPD&#41; frequently has prognostic implications&#46; Desaturation within the first minute of the walk 6-minute walk test will probably also occur in daily life activities and translate into hypoxaemic respiratory failure at rest in later years&#46; This study aimed at comparing these patients with those who desaturate after the first minute and determine potential markers&#46;</p></span> <span id="abst0010" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0015">Methods</span><p id="spar0010" class="elsevierStyleSimplePara elsevierViewall">We conducted a cross-sectional&#44; retrospective study collecting data on respiratory function tests&#44; cardiovascular comorbidity&#44; body mass index&#44; pack-year index&#44; 6-minute walk test outcomes&#44; BODE index&#44; and Charlson comorbidity index&#46; Patients who desaturated during the first minute of the test were referred to as early desaturators compared to the non-early ones&#46;</p></span> <span id="abst0015" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0020">Results</span><p id="spar0015" class="elsevierStyleSimplePara elsevierViewall">We observed a higher mean body mass index in early desaturating patients&#44; and an inverse relation as to the body mass index categories &#60;25&#44; 25&#8211;29&#44; and &#8805;30&#46; Early desaturators had a lower FEV<span class="elsevierStyleInf">1</span>&#47;FVC index&#46; The mean distance walked in the test was shorter in early than in non-early desaturators&#44; and they desaturated more deeply&#46;</p></span> <span id="abst0020" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0025">Conclusion</span><p id="spar0020" class="elsevierStyleSimplePara elsevierViewall">Overweight and obesity&#44; as determined by body mass index&#44; seem to behave like markers for early desaturation&#46; This simple anthropometric measure might indicate point to potential early desaturation in COPD patients&#46;</p></span>"
        "secciones" => array:4 [
          0 => array:2 [
            "identificador" => "abst0005"
            "titulo" => "Background"
          ]
          1 => array:2 [
            "identificador" => "abst0010"
            "titulo" => "Methods"
          ]
          2 => array:2 [
            "identificador" => "abst0015"
            "titulo" => "Results"
          ]
          3 => array:2 [
            "identificador" => "abst0020"
            "titulo" => "Conclusion"
          ]
        ]
      ]
    ]
    "multimedia" => array:4 [
      0 => array:7 [
        "identificador" => "fig0005"
        "etiqueta" => "Figure 1"
        "tipo" => "MULTIMEDIAFIGURA"
        "mostrarFloat" => true
        "mostrarDisplay" => false
        "figura" => array:1 [
          0 => array:4 [
            "imagen" => "gr1.jpeg"
            "Alto" => 1271
            "Ancho" => 1604
            "Tamanyo" => 68461
          ]
        ]
        "descripcion" => array:1 [
          "en" => "<p id="spar0025" class="elsevierStyleSimplePara elsevierViewall">BMI in early and non early desaturators patients&#46;</p>"
        ]
      ]
      1 => array:7 [
        "identificador" => "fig0010"
        "etiqueta" => "Figure 2"
        "tipo" => "MULTIMEDIAFIGURA"
        "mostrarFloat" => true
        "mostrarDisplay" => false
        "figura" => array:1 [
          0 => array:4 [
            "imagen" => "gr2.jpeg"
            "Alto" => 1660
            "Ancho" => 1590
            "Tamanyo" => 99591
          ]
        ]
        "descripcion" => array:1 [
          "en" => "<p id="spar0030" class="elsevierStyleSimplePara elsevierViewall">ROC curve IMC and early desaturators&#46;</p>"
        ]
      ]
      2 => array:8 [
        "identificador" => "tbl0005"
        "etiqueta" => "Table 1"
        "tipo" => "MULTIMEDIATABLA"
        "mostrarFloat" => true
        "mostrarDisplay" => false
        "detalles" => array:1 [
          0 => array:3 [
            "identificador" => "at1"
            "detalle" => "Table "
            "rol" => "short"
          ]
        ]
        "tabla" => array:2 [
          "leyenda" => "<p id="spar0040" class="elsevierStyleSimplePara elsevierViewall">Data are given as median &#40;25th&#44; 75th percentile&#41; or mean<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>SD &#40;mean<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>standard deviation&#41;&#59; FEV<span class="elsevierStyleInf">1</span>&#58; forced expiratory volume in 1<span class="elsevierStyleHsp" style=""></span>s&#46;</p>"
          "tablatextoimagen" => array:1 [
            0 => array:2 [
              "tabla" => array:1 [
                0 => """
                  <table border="0" frame="\n
                  \t\t\t\t\tvoid\n
                  \t\t\t\t" class=""><thead title="thead"><tr title="table-row"><th class="td" title="table-head  " align="left" valign="top" scope="col" style="border-bottom: 2px solid black">Variables&#44; units&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th><th class="td" title="table-head  " align="" valign="top" scope="col" style="border-bottom: 2px solid black">&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th></tr></thead><tbody title="tbody"><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Gender male &#40;&#37;&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">79&#37;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Age&#44; in years median &#40;P<span class="elsevierStyleInf">25</span>&#8211;P<span class="elsevierStyleInf">75</span>&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">68 &#40;61&#8211;76&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Charlson index&#44; median &#40;P<span class="elsevierStyleInf">25</span>&#8211;P<span class="elsevierStyleInf">75</span>&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">5 &#40;3&#8211;7&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">BODE index&#44; median &#40;P<span class="elsevierStyleInf">25</span>&#8211;P<span class="elsevierStyleInf">75</span>&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">4 &#40;2&#8211;5&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">FEV<span class="elsevierStyleInf">1</span> &#40;&#37; predicted&#41;&#44; mean<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>SD&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">46<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>18&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Initial SpO2 &#40;&#37;&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">94<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>2&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">6-min walk distance &#40;m&#41;&#44; mean<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>SD&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">415<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>117&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Nadir SpO2 &#40;&#37;&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">85<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>4&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Time to SpO2 &#60;90&#37;&#44; median &#40;P<span class="elsevierStyleInf">25</span>&#8211;P<span class="elsevierStyleInf">75</span>&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">1&#58;34 &#40;0&#58;49&#8211;2&#58;18&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr></tbody></table>
                  """
              ]
              "imagenFichero" => array:1 [
                0 => "xTab1864235.png"
              ]
            ]
          ]
        ]
        "descripcion" => array:1 [
          "en" => "<p id="spar0035" class="elsevierStyleSimplePara elsevierViewall">Baseline characteristics of patients with exercise-induced desaturation&#46;</p>"
        ]
      ]
      3 => array:8 [
        "identificador" => "tbl0010"
        "etiqueta" => "Table 2"
        "tipo" => "MULTIMEDIATABLA"
        "mostrarFloat" => true
        "mostrarDisplay" => false
        "detalles" => array:1 [
          0 => array:3 [
            "identificador" => "at2"
            "detalle" => "Table "
            "rol" => "short"
          ]
        ]
        "tabla" => array:2 [
          "leyenda" => "<p id="spar0050" class="elsevierStyleSimplePara elsevierViewall">Data are given as median &#40;25th&#44; 75th percentile&#41; or mean<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>SD &#40;mean<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>standard deviation&#41;&#46; Pearson Chi-squared&#44; Mann&#8211;Whitney <span class="elsevierStyleItalic">U</span>&#44; or Student <span class="elsevierStyleItalic">t</span>-test were applied&#46; BMI&#58; body mass index&#59; FEV<span class="elsevierStyleInf">1</span>&#58; forced expiratory volume in 1<span class="elsevierStyleHsp" style=""></span>s&#59; FVC forced vital capacity&#59; FEV<span class="elsevierStyleInf">1</span>&#47;FVC index&#59; IC&#58; inspiratory capacity&#59; RV&#58; residual volume&#59; TLC&#58; total lung capacity&#59; DLCO&#58; carbon monoxide diffusion capacity&#46; mMRC&#58; modified Medical Research Council scale&#46;</p>"
          "tablatextoimagen" => array:1 [
            0 => array:2 [
              "tabla" => array:1 [
                0 => """
                  <table border="0" frame="\n
                  \t\t\t\t\tvoid\n
                  \t\t\t\t" class=""><thead title="thead"><tr title="table-row"><th class="td-with-role" title="table-head ; entry_with_role_rowhead " align="left" valign="top" scope="col">Variables&#44; units&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th><th class="td" title="table-head  " align="left" valign="top" scope="col">Early&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th><th class="td" title="table-head  " align="left" valign="top" scope="col">Non early&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th><th class="td" title="table-head  " align="left" valign="top" scope="col"><span class="elsevierStyleItalic">p</span>-value&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th></tr><tr title="table-row"><th class="td" title="table-head  " align="" valign="top" scope="col" style="border-bottom: 2px solid black">&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th><th class="td" title="table-head  " align="left" valign="top" scope="col" style="border-bottom: 2px solid black">&#40;<span class="elsevierStyleItalic">n</span><span class="elsevierStyleHsp" style=""></span>&#61;<span class="elsevierStyleHsp" style=""></span>32&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th><th class="td" title="table-head  " align="left" valign="top" scope="col" style="border-bottom: 2px solid black">&#40;<span class="elsevierStyleItalic">n</span><span class="elsevierStyleHsp" style=""></span>&#61;<span class="elsevierStyleHsp" style=""></span>74&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th><th class="td" title="table-head  " align="" valign="top" scope="col" style="border-bottom: 2px solid black">&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th></tr></thead><tbody title="tbody"><tr title="table-row"><td class="td" title="table-entry  " colspan="4" align="left" valign="top"><span class="elsevierStyleBold">Baseline</span></td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">Age&#44; years&#44; median &#40;P</span><span class="elsevierStyleInf"><span class="elsevierStyleItalic">25</span></span><span class="elsevierStyleItalic">&#8211;P</span><span class="elsevierStyleInf"><span class="elsevierStyleItalic">75</span></span><span class="elsevierStyleItalic">&#41;</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">68 &#40;63&#8211;76&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">68 &#40;60&#8211;75&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;620&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">BMI &#40;kg&#47;m</span><span class="elsevierStyleSup"><span class="elsevierStyleItalic">2</span></span><span class="elsevierStyleItalic">&#41;&#44; mean</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">&#177;</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">SD</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">29<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>5&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">25<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>6&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;002&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">Haemoglobin g&#47;dl&#44; mean</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">&#177;</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">SD</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">14&#46;2<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>2&#46;0&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">14&#46;4<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>1&#46;7&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;667&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">Smoking pack-year index&#44; median &#40;P</span><span class="elsevierStyleInf"><span class="elsevierStyleItalic">25</span></span><span class="elsevierStyleItalic">&#8211;P</span><span class="elsevierStyleInf"><span class="elsevierStyleItalic">75</span></span><span class="elsevierStyleItalic">&#41;</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">40 &#40;10&#8211;68&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">40 &#40;14&#8211;53&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;939&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">Dyspnoea&#44; mMRC scale&#44; median &#40;P</span><span class="elsevierStyleInf"><span class="elsevierStyleItalic">25</span></span><span class="elsevierStyleItalic">&#8211;P</span><span class="elsevierStyleInf"><span class="elsevierStyleItalic">75</span></span><span class="elsevierStyleItalic">&#41;</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">2 &#40;1&#8211;3&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">2 &#40;1&#8211;3&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;997&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">GOLD 2009</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="" valign="top">&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="" valign="top">&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;23&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleHsp" style=""></span>Stage I &#40;&#37;&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">6&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">7&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="" valign="top">&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleHsp" style=""></span>Stage II &#40;&#37;&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">44&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">23&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="" valign="top">&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleHsp" style=""></span>Stage III &#40;&#37;&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">37&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">51&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="" valign="top">&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleHsp" style=""></span>Stage IV &#40;&#37;&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">13&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">19&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="" valign="top">&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">GOLD 2017</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="" valign="top">&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="" valign="top">&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;986&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleHsp" style=""></span>Stage A &#40;&#37;&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">22&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">20&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="" valign="top">&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleHsp" style=""></span>Stage B &#40;&#37;&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">41&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">39&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="" valign="top">&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleHsp" style=""></span>Stage C &#40;&#37;&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">6&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">7&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="" valign="top">&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleHsp" style=""></span>Stage D &#40;&#37;&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">31&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">35&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="" valign="top">&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">Charlson index&#44; median &#40;P</span><span class="elsevierStyleInf"><span class="elsevierStyleItalic">25</span></span><span class="elsevierStyleItalic">&#8211;P</span><span class="elsevierStyleInf"><span class="elsevierStyleItalic">75</span></span><span class="elsevierStyleItalic">&#41;</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">5 &#40;4&#8211;7&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">5 &#40;3&#8211;6&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;129&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">BODE index&#44; median &#40;P</span><span class="elsevierStyleInf"><span class="elsevierStyleItalic">25</span></span><span class="elsevierStyleItalic">&#8211;P</span><span class="elsevierStyleInf"><span class="elsevierStyleItalic">75</span></span><span class="elsevierStyleItalic">&#41;</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">4 &#40;2&#8211;5&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">4 &#40;2&#8211;5&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;913&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="table-entry  " colspan="4" align="left" valign="top"><span class="elsevierStyleBold">Pulmonary function parameters</span></td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">6-min walk distance &#40;m&#41;&#44; mean</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">&#177;</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">SD</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">371<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>105&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">435<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>117&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;011&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">Time to SpO2 &#40;s&#41; &#60;90&#37;&#44; median &#40;P</span><span class="elsevierStyleInf"><span class="elsevierStyleItalic">25</span></span><span class="elsevierStyleItalic">&#8211;P</span><span class="elsevierStyleInf"><span class="elsevierStyleItalic">75</span></span><span class="elsevierStyleItalic">&#41;</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">40 &#40;35&#8211;46&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">110 &#40;90&#8211;150&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">&#60;0&#46;0001&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">Initial SpO2 &#40;&#37;&#41;&#44; mean</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">&#177;</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">SD</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">93<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>1&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">94<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>2&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;002&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">Nadir SpO2 &#40;&#37;&#41;&#44; mean</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">&#177;</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">SD</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">83<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>5&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">86<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>3&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;001&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">Initial to nadir SpO2 &#40;&#37;&#41;&#44; mean</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">&#177;</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">SD</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">11<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>5&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">8<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>4&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;023&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">FEV</span><span class="elsevierStyleInf"><span class="elsevierStyleItalic">1</span></span><span class="elsevierStyleItalic">&#47;FVC &#40;&#37; predicted&#41;&#44; mean</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">&#177;</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">SD</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">47<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>12&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">41<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>11&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;007&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">FEV</span><span class="elsevierStyleInf"><span class="elsevierStyleItalic">1</span></span><span class="elsevierStyleItalic">litres &#40;&#37; predicted&#41;&#44; mean</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">&#177;</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">SD</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">1&#46;2<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>0&#46;577 &#40;48<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>17&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">1&#46;2<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>0&#46;654 &#40;45<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>19&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;421&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">FVC litres &#40;&#37; predicted&#41;&#44; mean</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">&#177;</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">SD</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">2&#46;5<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>0&#46;673 &#40;76<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>19&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">2&#46;8<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>0&#46;795 &#40;81<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>19&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;196&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">IC litres &#40;&#37; predicted&#41;&#44; mean</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">&#177;</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">SD</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">2&#46;2<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>0&#46;703 &#40;88<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>22&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">2&#46;3<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>0&#46;695 &#40;87<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>23&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;913&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">RV&#47;TLC&#44; mean</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">&#177;</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">SD</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">142<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>35&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">142<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>32&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;979&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">DLCO &#40;&#37; predicted&#41;&#44; mean</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">&#177;</span><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">SD</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">51<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>18&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">55<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>21&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;346&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="table-entry  " colspan="4" align="left" valign="top"><span class="elsevierStyleBold">Comorbidities</span></td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">Hypertension &#40;&#37;&#41;</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">59&#37;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">49&#37;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;310&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">Dyslipidaemia &#40;&#37;&#41;</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">59&#37;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">49&#37;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;310&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">Diabetes mellitus &#40;&#37;&#41;</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">28&#37;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">15&#37;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;109&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">Ischaemic heart disease &#40;&#37;&#41;</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">9&#37;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">15&#37;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;443&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">Heart failure &#40;&#37;&#41;</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">16&#37;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">9&#37;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;358&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top"><span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">Arrhythmia &#40;&#37;&#41;</span>&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">16&#37;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">15&#37;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">0&#46;920&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr></tbody></table>
                  """
              ]
              "imagenFichero" => array:1 [
                0 => "xTab1864234.png"
              ]
            ]
          ]
        ]
        "descripcion" => array:1 [
          "en" => "<p id="spar0045" class="elsevierStyleSimplePara elsevierViewall">Characteristic of early and non early desaturators patients&#46;</p>"
        ]
      ]
    ]
    "bibliografia" => array:2 [
      "titulo" => "References"
      "seccion" => array:1 [
        0 => array:2 [
          "identificador" => "bibs0015"
          "bibliografiaReferencia" => array:17 [
            0 => array:3 [
              "identificador" => "bib0090"
              "etiqueta" => "1"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Exertional hypoxemia in stable COPD is common and predicted by circulating proadrenomedullin"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:19 [
                            0 => "D&#46; Stolz"
                            1 => "W&#46; Boersma"
                            2 => "F&#46; Blasi"
                            3 => "R&#46; Louis"
                            4 => "B&#46; Milenkovic"
                            5 => "K&#46; Kostikas"
                            6 => "J&#46;G&#46; Aerts"
                            7 => "G&#46; Rohde"
                            8 => "A&#46; Lacoma"
                            9 => "J&#46; Rakic"
                            10 => "L&#46; Boeck"
                            11 => "P&#46; Castellotti"
                            12 => "A&#46; Scherr"
                            13 => "A&#46; Marin"
                            14 => "S&#46; Hertel"
                            15 => "S&#46; Giersdorf"
                            16 => "A&#46; Torres"
                            17 => "T&#46; Welte"
                            18 => "M&#46; Tamm"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1378/chest.13-1967"
                      "Revista" => array:6 [
                        "tituloSerie" => "Chest"
                        "fecha" => "2014"
                        "volumen" => "146"
                        "paginaInicial" => "328"
                        "paginaFinal" => "338"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/24722847"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            1 => array:3 [
              "identificador" => "bib0095"
              "etiqueta" => "2"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Prevalence and prediction of exercise-induced oxygen desaturation in patients with chronic obstructive pulmonary disease"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => true
                          "autores" => array:6 [
                            0 => "A&#46;J&#46; Van Gestel"
                            1 => "C&#46;F&#46; Clarenbach"
                            2 => "A&#46;C&#46; Stowhas"
                            3 => "S&#46; Teschler"
                            4 => "E&#46;W&#46; Russi"
                            5 => "H&#46; Teschler"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1159/000332833"
                      "Revista" => array:6 [
                        "tituloSerie" => "Respiration"
                        "fecha" => "2012"
                        "volumen" => "84"
                        "paginaInicial" => "353"
                        "paginaFinal" => "359"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/22269699"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            2 => array:3 [
              "identificador" => "bib0100"
              "etiqueta" => "3"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Dynamic hyperinflation correlates with exertional oxygen desaturation in patients with chronic obstructive pulmonary disease"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:5 [
                            0 => "M&#46;A&#46; Zafar"
                            1 => "W&#46; Tsuang"
                            2 => "L&#46; Lach"
                            3 => "W&#46; Eschenbacher"
                            4 => "R&#46;J&#46; Panos"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1007/s00408-012-9443-3"
                      "Revista" => array:6 [
                        "tituloSerie" => "Lung"
                        "fecha" => "2013"
                        "volumen" => "191"
                        "paginaInicial" => "177"
                        "paginaFinal" => "182"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/23283384"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            3 => array:3 [
              "identificador" => "bib0105"
              "etiqueta" => "4"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Resting single-breath diffusing capacity as a screening test for exercise-induced hypoxemia"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "M&#46;A&#46; Kelley"
                            1 => "R&#46;A&#46; Panettieri Jr&#46;"
                            2 => "A&#46;V&#46; Krupinski"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "Am J Med"
                        "fecha" => "1986"
                        "volumen" => "80"
                        "paginaInicial" => "807"
                        "paginaFinal" => "812"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/3706368"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            4 => array:3 [
              "identificador" => "bib0110"
              "etiqueta" => "5"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "The diffusing capacity as a predictor of arterial oxygen desaturation during exercise in patients with chronic obstructive pulmonary disease"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:4 [
                            0 => "G&#46;R&#46; Owens"
                            1 => "R&#46;M&#46; Rogers"
                            2 => "B&#46;E&#46; Pennock"
                            3 => "D&#46; Levin"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1056/NEJM198405103101903"
                      "Revista" => array:6 [
                        "tituloSerie" => "N Engl J Med"
                        "fecha" => "1984"
                        "volumen" => "310"
                        "paginaInicial" => "1218"
                        "paginaFinal" => "1221"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/6709028"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            5 => array:3 [
              "identificador" => "bib0115"
              "etiqueta" => "6"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Predicting walking-induced oxygen desaturations in COPD patients&#58; a statistical model"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => true
                          "autores" => array:6 [
                            0 => "E&#46; Crisafulli"
                            1 => "A&#46; Iattoni"
                            2 => "E&#46; Venturelli"
                            3 => "G&#46; Siscaro"
                            4 => "C&#46; Beneventi"
                            5 => "A&#46; Cesario"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.4187/respcare.02321"
                      "Revista" => array:6 [
                        "tituloSerie" => "Respir Care"
                        "fecha" => "2013"
                        "volumen" => "58"
                        "paginaInicial" => "1495"
                        "paginaFinal" => "1503"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/23362168"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            6 => array:3 [
              "identificador" => "bib0120"
              "etiqueta" => "7"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "CT scores of emphysema and oxygen desaturation during low-grade exercise in patients with emphysema"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => true
                          "autores" => array:6 [
                            0 => "O&#46; Taguchi"
                            1 => "E&#46;C&#46; Gabazza"
                            2 => "M&#46; Yoshida"
                            3 => "H&#46; Yasui"
                            4 => "T&#46; Kobayashi"
                            5 => "H&#46; Yuda"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "Acta Radiol"
                        "fecha" => "2000"
                        "volumen" => "41"
                        "paginaInicial" => "196"
                        "paginaFinal" => "197"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/10741797"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            7 => array:3 [
              "identificador" => "bib0125"
              "etiqueta" => "8"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Determinants of exercise-induced oxygen desaturation including pulmonary emphysema in COPD&#58; results from the ECLIPSE study"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => true
                          "autores" => array:6 [
                            0 => "V&#46; Andrianopoulos"
                            1 => "B&#46;R&#46; Celli"
                            2 => "F&#46;M&#46; Franssen"
                            3 => "V&#46;M&#46; Pinto-Plata"
                            4 => "P&#46;M&#46; Calverley"
                            5 => "L&#46;E&#46; Vanfleteren"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1016/j.rmed.2016.08.023"
                      "Revista" => array:6 [
                        "tituloSerie" => "Respir Med"
                        "fecha" => "2016"
                        "volumen" => "119"
                        "paginaInicial" => "87"
                        "paginaFinal" => "95"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/27692154"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            8 => array:3 [
              "identificador" => "bib0130"
              "etiqueta" => "9"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Time to desaturation in the 6-min walking distance test predicts 24-hour oximetry in COPD with a PO2 between 60 and 70<span class="elsevierStyleHsp" style=""></span>mmHg"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:6 [
                            0 => "I&#46; Garc&#237;a-Talavera"
                            1 => "C&#46;H&#46; Garc&#237;a"
                            2 => "C&#46;C&#46; Macario"
                            3 => "J&#46;P&#46; de Torres"
                            4 => "B&#46;R&#46; Celli"
                            5 => "A&#46; Aguirre-Jaime"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1016/j.rmed.2008.02.004"
                      "Revista" => array:6 [
                        "tituloSerie" => "Respir Med"
                        "fecha" => "2008"
                        "volumen" => "102"
                        "paginaInicial" => "1026"
                        "paginaFinal" => "1032"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/18343649"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            9 => array:3 [
              "identificador" => "bib0135"
              "etiqueta" => "10"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Time to desaturation less than one minute predicts the need for long-term home oxygen therapy"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => true
                          "autores" => array:6 [
                            0 => "I&#46; Garcia-Talavera"
                            1 => "A&#46; Tauroni"
                            2 => "J&#46;L&#46; Trujillo"
                            3 => "R&#46; Pitti"
                            4 => "L&#46; Eiroa"
                            5 => "A&#46; Aguirre-Jame"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.4187/respcare.01164"
                      "Revista" => array:6 [
                        "tituloSerie" => "Respir Care"
                        "fecha" => "2011"
                        "volumen" => "56"
                        "paginaInicial" => "1812"
                        "paginaFinal" => "1817"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/21605486"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            10 => array:3 [
              "identificador" => "bib0140"
              "etiqueta" => "11"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Consenso SEEDO 2007 para la evaluaci&#243;n del sobrepeso y la obesidad y el establecimiento de criterios de intervenci&#243;n terap&#233;utica"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => true
                          "autores" => array:6 [
                            0 => "M&#46;A&#46; Rubio"
                            1 => "J&#46; Salas-Salvad&#243;"
                            2 => "M&#46; Barbany"
                            3 => "B&#46; Moreno"
                            4 => "J&#46; Aranceta"
                            5 => "B&#46; Bellido"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:4 [
                        "tituloSerie" => "Rev Esp Obes"
                        "fecha" => "2007"
                        "paginaInicial" => "7"
                        "paginaFinal" => "48"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            11 => array:3 [
              "identificador" => "bib0145"
              "etiqueta" => "12"
              "referencia" => array:1 [
                0 => array:3 [
                  "comentario" => "<a class="elsevierStyleInterRef" target="_blank" id="intr0005" href="http://www.goldcopd.org/">http&#58;&#47;&#47;www&#46;goldcopd&#46;org</a>"
                  "contribucion" => array:1 [
                    0 => array:1 [
                      "titulo" => "Global strategy for the diagnosis&#44; management and prevention of COPD&#44; global initiative for chronic obstructive lung disease &#40;GOLD&#41;"
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Libro" => array:1 [
                        "fecha" => "2009"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            12 => array:3 [
              "identificador" => "bib0150"
              "etiqueta" => "13"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Guidelines for the six-minute walk test"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:1 [
                            0 => "A&#46;T&#46;S&#46; Statement&#58;"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1164/ajrccm.166.1.at1102"
                      "Revista" => array:6 [
                        "tituloSerie" => "Am J Respir Crit Care Med"
                        "fecha" => "2002"
                        "volumen" => "166"
                        "paginaInicial" => "111"
                        "paginaFinal" => "117"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/12091180"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            13 => array:3 [
              "identificador" => "bib0155"
              "etiqueta" => "14"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "The connection between chronic obstructive pulmonary disease symptoms and hyperinflation and its impact on exercise and function"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:1 [
                            0 => "C&#46;B&#46; Cooper"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1016/j.amjmed.2006.08.004"
                      "Revista" => array:7 [
                        "tituloSerie" => "Am J Med"
                        "fecha" => "2006"
                        "volumen" => "119"
                        "numero" => "Suppl 1"
                        "paginaInicial" => "21"
                        "paginaFinal" => "31"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/16996896"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            14 => array:3 [
              "identificador" => "bib0160"
              "etiqueta" => "15"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Pulmonary characteristics in COPD and mechanisms of increased work of breathing"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "S&#46;H&#46; Loring"
                            1 => "M&#46; Garcia-Jacques"
                            2 => "A&#46; Malhotra"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1152/japplphysiol.00008.2009"
                      "Revista" => array:6 [
                        "tituloSerie" => "J Appl Physiol"
                        "fecha" => "1985 2009"
                        "volumen" => "107"
                        "paginaInicial" => "309"
                        "paginaFinal" => "314"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/19359620"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            15 => array:3 [
              "identificador" => "bib0165"
              "etiqueta" => "16"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Distance and oxygen desaturation in 6-min walk test predict prognosis in COPD patients"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:15 [
                            0 => "N&#46; Takigawa"
                            1 => "A&#46; Tada"
                            2 => "R&#46; Soda"
                            3 => "H&#46; Date"
                            4 => "M&#46; Yamashita"
                            5 => "S&#46; Endo"
                            6 => "S&#46; Takahashi"
                            7 => "N&#46; Kawata"
                            8 => "T&#46; Shibayama"
                            9 => "N&#46; Hamada"
                            10 => "M&#46; Sakaguchi"
                            11 => "A&#46; Hirano"
                            12 => "G&#46; Kimura"
                            13 => "C&#46; Okada"
                            14 => "Takahashi K&#58;"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1016/j.rmed.2006.06.017"
                      "Revista" => array:6 [
                        "tituloSerie" => "Respir Med"
                        "fecha" => "2007"
                        "volumen" => "101"
                        "paginaInicial" => "561"
                        "paginaFinal" => "567"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/16899358"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            16 => array:3 [
              "identificador" => "bib0170"
              "etiqueta" => "17"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Metabolic and inflammatory profile in obese patients with chronic obstructive pulmonary disease"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:7 [
                            0 => "M&#46; Poulain"
                            1 => "M&#46; Doucet"
                            2 => "V&#46; Drapeau"
                            3 => "G&#46; Fournier"
                            4 => "A&#46; Tremblay"
                            5 => "P&#46; Poirier"
                            6 => "F&#46; Maltais"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1177/1479972307087205"
                      "Revista" => array:6 [
                        "tituloSerie" => "Chron Respir Dis"
                        "fecha" => "2008"
                        "volumen" => "5"
                        "paginaInicial" => "35"
                        "paginaFinal" => "41"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/18303100"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
          ]
        ]
      ]
    ]
  ]
  "idiomaDefecto" => "en"
  "url" => "/25310437/0000002400000005/v1_201810040621/S253104371830076X/v1_201810040621/en/main.assets"
  "Apartado" => array:4 [
    "identificador" => "72878"
    "tipo" => "SECCION"
    "en" => array:2 [
      "titulo" => "Original articles"
      "idiomaDefecto" => true
    ]
    "idiomaDefecto" => "en"
  ]
  "PDF" => "https://static.elsevier.es/multimedia/25310437/0000002400000005/v1_201810040621/S253104371830076X/v1_201810040621/en/main.pdf?idApp=UINPBA00004E&text.app=https://journalpulmonology.org/"
  "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/S253104371830076X?idApp=UINPBA00004E"
]

Article information

ISSN: 25310437
Original language: English

DOI:10.1016/j.pulmoe.2018.04.007

The statistics are updated each day

Year/Month	Html	Pdf	Total

2024 November	10	7	17
2024 October	58	33	91
2024 September	69	36	105
2024 August	81	29	110
2024 July	51	32	83
2024 June	47	30	77
2024 May	57	32	89
2024 April	51	33	84
2024 March	41	27	68
2024 February	32	23	55
2024 January	45	25	70
2023 December	27	20	47
2023 November	44	43	87
2023 October	35	30	65
2023 September	26	33	59
2023 August	26	20	46
2023 July	31	33	64
2023 June	24	18	42
2023 May	47	33	80
2023 April	32	26	58
2023 March	64	26	90
2023 February	52	26	78
2023 January	24	19	43
2022 December	58	33	91
2022 November	39	36	75
2022 October	77	38	115
2022 September	29	50	79
2022 August	39	45	84
2022 July	26	34	60
2022 June	23	27	50
2022 May	37	34	71
2022 April	25	33	58
2022 March	29	50	79
2022 February	27	36	63
2022 January	32	47	79
2021 December	25	45	70
2021 November	29	42	71
2021 October	36	48	84
2021 September	20	43	63
2021 August	18	26	44
2021 July	25	21	46
2021 June	23	25	48
2021 May	39	40	79
2021 April	69	98	167
2021 March	44	35	79
2021 February	18	21	39
2021 January	31	27	58
2020 December	21	13	34
2020 November	23	17	40
2020 October	27	29	56
2020 September	33	33	66
2020 August	43	35	78
2020 July	43	25	68
2020 June	29	22	51
2020 May	44	30	74
2020 April	47	5	52
2020 March	31	24	55
2020 February	41	18	59
2020 January	39	30	69
2019 December	46	23	69
2019 November	42	21	63
2019 October	46	29	75
2019 September	46	25	71
2019 August	47	23	70
2019 July	41	32	73
2019 June	41	22	63
2019 May	60	30	90
2019 April	79	46	125
2019 March	45	28	73
2019 February	42	35	77
2019 January	55	49	104
2018 December	20	24	44
2018 November	20	0	20
2018 October	4	2	6

Show all

Indexed in:

Follow us:

Statistics

Indexed in:

Follow us:

Statistics

Subscribe to our newsletter