Exercise capacity impairment in COPD patients with comorbidities

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Abbreviations: SEM, standard error of the mean; SD, standard deviation." ] ] ] "autores" => array:1 [ 0 => array:2 [ "autoresLista" => "M. Kosacka, P. Piesiak, I. Porebska, R. Jankowska" "autores" => array:4 [ 0 => array:2 [ "Iniciales" => "M." "apellidos" => "Kosacka" ] 1 => array:2 [ "Iniciales" => "P." "apellidos" => "Piesiak" ] 2 => array:2 [ "Iniciales" => "I." "apellidos" => "Porebska" ] 3 => array:2 [ "Iniciales" => "R." "apellidos" => "Jankowska" ] ] ] ] ] "idiomaDefecto" => "en" "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/X0873215915364922?idApp=UINPBA00004E" "url" => "/08732159/0000002100000005/v0_201604141143/X0873215915364922/v0_201604141143/en/main.assets" ] "itemAnterior" => array:16 [ "pii" => "X0873215915364906" "issn" => "08732159" "doi" => "10.1016/j.rppnen.2015.07.001" "estado" => "S300" "fechaPublicacion" => "2015-09-01" "documento" => "article" "licencia" => "http://www.elsevier.com/open-access/userlicense/1.0/" "subdocumento" => "fla" "cita" => "Rev Port Pneumol. 2015;21:230-2" "abierto" => array:3 [ "ES" => true "ES2" => true "LATM" => true ] "gratuito" => true "lecturas" => array:2 [ "total" => 4033 "formatos" => array:3 [ "EPUB" => 260 "HTML" => 2797 "PDF" => 976 ] ] "en" => array:7 [ "idiomaDefecto" => true "titulo" => "Portugal at the cross road of international chronic respiratory programmes" "tienePdf" => "en" "tieneTextoCompleto" => "en" "paginas" => array:1 [ 0 => array:2 [ "paginaInicial" => "230" "paginaFinal" => "232" ] ] "contieneTextoCompleto" => array:1 [ "en" => true ] "contienePdf" => array:1 [ "en" => true ] ] "idiomaDefecto" => "en" "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/X0873215915364906?idApp=UINPBA00004E" "url" => "/08732159/0000002100000005/v0_201604141143/X0873215915364906/v0_201604141143/en/main.assets" ] "asociados" => array:1 [ 0 => array:19 [ "pii" => "S2173511515001487" "issn" => "21735115" "doi" => "10.1016/j.rppnen.2015.08.001" "estado" => "S300" "fechaPublicacion" => "2015-09-01" "aid" => "1084" "copyright" => "Sociedade Portuguesa de Pneumologia" "documento" => "simple-article" "crossmark" => 1 "licencia" => "http://www.elsevier.com/open-access/userlicense/1.0/" "subdocumento" => "edi" "cita" => "Rev Port Pneumol. 2015;21:227-9" "abierto" => array:3 [ "ES" => true "ES2" => true "LATM" => true ] "gratuito" => true "lecturas" => array:2 [ "total" => 1738 "formatos" => array:3 [ "EPUB" => 244 "HTML" => 977 "PDF" => 517 ] ] "en" => array:10 [ "idiomaDefecto" => true "cabecera" => "Editorial" "titulo" => "Impaired function in the complex patient with COPD: a matter to be considered" "tienePdf" => "en" "tieneTextoCompleto" => "en" "paginas" => array:1 [ 0 => array:2 [ "paginaInicial" => "227" "paginaFinal" => "229" ] ] "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" => 966 "Ancho" => 2296 "Tamanyo" => 67191 ] ] "descripcion" => array:1 [ "en" => "Relationship between number of the (considered) comorbidities and functional impairment as assessed by health status CAT score (from ref#11)." ] ] ] "autores" => array:1 [ 0 => array:2 [ "autoresLista" => "R. Tonelli, E.M. Clini" "autores" => array:2 [ 0 => array:2 [ "nombre" => "R." "apellidos" => "Tonelli" ] 1 => array:2 [ "nombre" => "E.M." "apellidos" => "Clini" ] ] ] ] ] "idiomaDefecto" => "en" "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/S2173511515001487?idApp=UINPBA00004E" "url" => "/21735115/0000002100000005/v3_201605090007/S2173511515001487/v3_201605090007/en/main.assets" ] ] "en" => array:12 [ "idiomaDefecto" => true "titulo" => "Exercise capacity impairment in COPD patients with comorbidities" "tieneTextoCompleto" => true "paginas" => array:1 [ 0 => array:2 [ "paginaInicial" => "233" "paginaFinal" => "238" ] ] "autores" => array:1 [ 0 => array:4 [ "autoresLista" => "G.P.F. Da Silva, M.T.A. Pessoa Morano, A.G. De Matos Cavalcante, N.M. De Andrade, E. De Francesco Daher, E.D.B. Pereira" "autores" => array:6 [ 0 => array:3 [ "nombre" => "G.P.F." "apellidos" => "Da Silva" "referencia" => array:2 [ 0 => array:2 [ "etiqueta" => "a" "identificador" => "affa" ] 1 => array:2 [ "etiqueta" => "b" "identificador" => "affb" ] ] ] 1 => array:3 [ "nombre" => "M.T.A. Pessoa" "apellidos" => "Morano" "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "c" "identificador" => "affc" ] ] ] 2 => array:3 [ "nombre" => "A.G. De Matos" "apellidos" => "Cavalcante" "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "a" "identificador" => "affa" ] ] ] 3 => array:3 [ "Iniciales" => "N.M." "apellidos" => "De Andrade" "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "a" "identificador" => "affa" ] ] ] 4 => array:3 [ "nombre" => "E. De Francesco" "apellidos" => "Daher" "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "a" "identificador" => "affa" ] ] ] 5 => array:4 [ "nombre" => "E.D.B." "apellidos" => "Pereira" "email" => array:1 [ 0 => "eanes@fortalnet.com.br" ] "referencia" => array:2 [ 0 => array:2 [ "etiqueta" => "a" "identificador" => "affa" ] 1 => array:2 [ "etiqueta" => "*" "identificador" => "cor1" ] ] ] ] "afiliaciones" => array:3 [ 0 => array:3 [ "entidad" => "Universidade Federal do Ceará – UFC, Fortaleza, Brazil" "etiqueta" => "a" "identificador" => "affa" ] 1 => array:3 [ "entidad" => "Universidade de Fortaleza – UNIFOR, Fortaleza, Brazil" "etiqueta" => "b" "identificador" => "affb" ] 2 => array:3 [ "entidad" => "Hospital de Messejana Dr. Carlos Alberto Studart Gomes, Fortaleza, Brazil" "etiqueta" => "c" "identificador" => "affc" ] ] "correspondencia" => array:1 [ 0 => array:3 [ "identificador" => "cor1" "etiqueta" => "*" "correspondencia" => "Corresponding author. eanes@fortalnet.com.br" ] ] ] ] "textoCompleto" => "<a name="sec0005" class="elsevierStyleCrossRefs"></a>IntroductionChronic obstructive pulmonary disease (COPD) is an important cause of impaired health-related quality of life, disability and death, with expressive social and economic repercussions.<a href="#bib34" class="elsevierStyleCrossRefs">1</a> It is a complex disease with pulmonary and systemic symptoms, frequently associated with comorbidities<a href="#bib35" class="elsevierStyleCrossRefs">2</a> that contribute to reduced health status and increased healthcare utilization, all-cause hospital admission, and mortality.<a href="#bib36" class="elsevierStyleCrossRefs">3</a>, <a href="#bib37" class="elsevierStyleCrossRefs">4</a> The prevalence of the different types of comorbidity varies somewhat across studies, depending on the patient population, the definition of diseases and methods of patient evaluation.<a href="#bib38" class="elsevierStyleCrossRefs">5</a>Hypertension, coronary disease and diabetes are frequent conditions associated with COPD and an increased risk of death.<a href="#bib39" class="elsevierStyleCrossRefs">6</a>, <a href="#bib40" class="elsevierStyleCrossRefs">7</a> The presence of these comorbidities appears to have a deleterious effect on several outcomes in COPD.<a href="#bib38" class="elsevierStyleCrossRefs">5</a>Endothelial dysfunction and increased arterial stiffness begin early in the course of COPD<a href="#bib41" class="elsevierStyleCrossRefs">8</a>, <a href="#bib42" class="elsevierStyleCrossRefs">9</a>, <a href="#bib43" class="elsevierStyleCrossRefs">10</a> and probably represent the onset of atherosclerotic disease. Data from one study, including 20,269 subjects, identified a 40% prevalence of hypertension among 76 patients with COPD.<a href="#bib40" class="elsevierStyleCrossRefs">7</a> Results from an observational study suggests that poorer health status, as indicated by a high COPD assessment test (CAT) score, may indicate the presence of certain comorbidities.<a href="#bib44" class="elsevierStyleCrossRefs">11</a>There is a growing body of evidence from some studies evaluating the impact of comorbidities on 6-min walking test (6MWT). Most of these studies have included patients with anxiety and depression.<a href="#bib45" class="elsevierStyleCrossRefs">12</a>, <a href="#bib46" class="elsevierStyleCrossRefs">13</a>, <a href="#bib47" class="elsevierStyleCrossRefs">14</a>, <a href="#bib48" class="elsevierStyleCrossRefs">15</a> Only one observational and longitudinal study has included 2164 patients with COPD associated with diabetes and cardiovascular disease.<a href="#bib49" class="elsevierStyleCrossRefs">16</a>A better understanding of the impact of comorbidities, particularly diabetes, hypertension and cardiovascular disease, among patients with COPD is required. In the current study, we have evaluated the impact of comorbidities, diabetes, hypertension and cardiovascular disease, on functional performance in patients with COPD, after controlling for the effects of potential confounders including age, severity of COPD and health status.<a name="sec0010" class="elsevierStyleCrossRefs"></a>Methods<a name="sec0015" class="elsevierStyleCrossRefs"></a>Patients and study designA cross-sectional study was conducted at two teaching hospitals in Fortaleza, Brazil, from January to December 2012. The research protocol was approved by local Research Ethics Committee (no. 880/12), and a written informed consent was obtained in all 96 cases. Patients were recruited during their initial assessment prior to enrollment in a 97 pulmonary rehabilitation program in the ambulatories of both hospitals. The inclusion criteria were, to be smoker or ex-smoker with a smoking history of at least 10 packs-years, aged 40–80 years, a previous diagnosis of COPD on stages II–IV (post-bronchodilator FEV1/FVC < 0.7 and FEV1 < 80% of predicted). All patients were clinically stable and without exacerbations for at least one month prior to recruitment.Patients with a primary diagnosis of asthma or other chronic respiratory diseases, with severe cognitive deficiency preventing them from understanding the questionnaire and patients with restricted mobility, were excluded.<a name="sec0020" class="elsevierStyleCrossRefs"></a>Assessment of patient's parametersSocio-demographic data were obtained through a structured questionnaire. Functional capacity was assessed by spirometry and 6MWT. The time allowed for patients to rest between the two tests was 1 h.Spirometry was conducted using an electronic spirometer in accordance with the guidelines of the American Thoracic Society/European Respiratory Society (ATS/ERS).<a href="#bib50" class="elsevierStyleCrossRefs">17</a>Functional exercise capacity was assessed by 6MWT. It was performed twice in a 30 m corridor. The patients were instructed to walk from end to end, covering as much ground as they could during the allotted time, as recommended by ATS guidelines.<a href="#bib51" class="elsevierStyleCrossRefs">18</a>Health-related quality of life was assessed by St. George's respiratory questionnaire (SGRQ). The SGRQ consists of 53 items, which can be aggregated into an overall score and three domain scores describing symptoms, activity and impact.<a href="#bib52" class="elsevierStyleCrossRefs">19</a> Current health was assessed by the COPD assessment test (CAT). This questionnaire consists of eight items that describe cough, phlegm, chest tightness, breathlessness going up hills/stairs, activity limitations at home, confidence leaving home, sleep and energy. Each item is scored from 0 to 5, thereby making the range of the total score from 0 to 40. Higher scores represent worse health.<a href="#bib53" class="elsevierStyleCrossRefs">20</a> Both, SGRQ and CAT were previously translated and validated for the Portuguese language.<a href="#bib54" class="elsevierStyleCrossRefs">21</a>, <a href="#bib55" class="elsevierStyleCrossRefs">22</a>, <a href="#bib56" class="elsevierStyleCrossRefs">23</a> The Brazilian version of SGRQ and CAT showed good psychometric properties. CAT showed an excellent inter-rater and intra-rater reliability (intraclass correlation coefficient [ICC] = 0.96; 95% CI: 0.93–0.97; p < 0.001; and ICC = 0.98; 95% CI: 0.96–0.98; p < 0.001, respectively).<a href="#bib56" class="elsevierStyleCrossRefs">23</a> SGRQ showed an intraclass correlation ratio for the total score of α = 0.79.<a href="#bib54" class="elsevierStyleCrossRefs">21</a> Both questionnaires were administered in the mode of face-to-face interview, by the same interviewer and prior to the start of the rehabilitation program.The diagnosis of the three studied comorbidities was based on data from medical records or upon clinical examination of patients. Subjects were classified as having diabetes if they reported a physician diagnosis of diabetes at baseline, or had impaired fasting or post-glucose load glucose levels (≥140 mg dL−1) upon examination.Subjects were classified as having coronary disease if they reported a previous physician diagnosis of myocardial infarction, angina or transient ischemic attacks, or when this information was registered in their medical records.Subjects were classified as having hypertension if they reported a physician diagnosis of hypertension, were taking drugs for hypertension or had evidence of hypertension during a clinical examination (diastolic blood pressure ≥90 mmHg or a systolic blood pressure ≥140 mmHg, on three measurements). Each subject was classified as having none, one, two or three comorbidities.<a name="sec0025" class="elsevierStyleCrossRefs"></a>Statistical analysesFor continuous variables, data are presented as means ± standard deviation (SD) and for categorical variables, as percentage. Normality distribution for continuous variables was assessed by means of the Kolmogorov–Smirnov test. One-way ANOVA with the Bonferroni correction was used to compare the means of the three groups. For comparison of proportions, the χ2 test for linear trends was used. A multiple linear regression was run to predict the impact of comorbidities on 6MWT adjusting for age, severity of COPD and CAT scores. The p values less than 0.05 were considered significant. All statistical analyses were performed with SPSS for Windows version 10.0 (SPSS Inc., Chicago, IL).<a name="sec0030" class="elsevierStyleCrossRefs"></a>ResultsDemographic, clinical, respiratory function and functional exercise capacity of the 79 subjects studied are shown in <a href="#t0005" class="elsevierStyleCrossRefs">Table 1</a>. According the new GOLD classification (GOLD 2014),<a href="#bib57" class="elsevierStyleCrossRefs">24</a> 4 (5%) patients were in grade A, 26 (32.9%) in grade B, 7 (8.8%) in grade C and 42 (53%) in grade D.Table 1. Demographic, clinical and functional characteristics of 79 COPD patients.<a name="t0005" class="elsevierStyleCrossRefs"></a><table><tr align="left"><td>Variable</td><td>COPD patients (79)</td></tr><tr align="left"><td colspan="2">Gender no (%)</td></tr><tr align="left"><td>Male</td><td>44 (56%)</td></tr><tr align="left"><td>Female</td><td>35 (44%)</td></tr><tr align="left"><td>Age, years mean ± SD</td><td>67 ± 8</td></tr><tr align="left"><td colspan="2"> </td></tr><tr align="left"><td colspan="2">COPD classification n (%)</td></tr><tr align="left"><td>Grade A</td><td>4 (5%)</td></tr><tr align="left"><td>Grade B</td><td>26 (32.9%)</td></tr><tr align="left"><td>Grade C</td><td>7 (8.8%)</td></tr><tr align="left"><td>Grade D</td><td>42 (53%)</td></tr><tr align="left"><td>FEV1 (%) mean ± SD</td><td>45.5 ± 13.2</td></tr><tr align="left"><td>FEV1 (l) mean ± SD</td><td>1.06 ± 0.377</td></tr><tr align="left"><td>FVC (%) mean ± SD</td><td>73.1 ± 16.5</td></tr><tr align="left"><td>FVC (l) mean ± SD</td><td>2.17 ± 0.694</td></tr><tr align="left"><td colspan="2"> </td></tr><tr align="left"><td colspan="2">SGRQ mean ± SD</td></tr><tr align="left"><td>Total mean ± SD</td><td>49.4 ± 18</td></tr><tr align="left"><td>Symptoms mean ± SD</td><td>45.5 ± 22.9</td></tr><tr align="left"><td>Activity mean ± SD</td><td>61 ± 23.1</td></tr><tr align="left"><td>Impact mean ± SD</td><td>41.7 ± 19.8</td></tr><tr align="left"><td>6MWT meters, mean ± SD</td><td>355 ± 93.8</td></tr><tr align="left"><td colspan="2"> </td></tr><tr align="left"><td colspan="2">Comorbidities</td></tr><tr align="left"><td>Total</td><td>43 (54%)</td></tr><tr align="left"><td>Hypertension</td><td>39 (49%)</td></tr><tr align="left"><td>Diabetes</td><td>14 (17%)</td></tr><tr align="left"><td>Coronary disease</td><td>19 (24%)</td></tr><tr align="left"><td colspan="2"> </td></tr><tr align="left"><td colspan="2">Numbers of comorbidity</td></tr><tr align="left"><td>zero</td><td>36 (45%)</td></tr><tr align="left"><td>One</td><td>19 (24%)</td></tr><tr align="left"><td>Two or three</td><td>24 (30%)</td></tr></table>The mean age of the patients was 67 ± 8 years and 44 (55%) were male. Fifty four percent of patients had at least one of three studied comorbidities. The sample was stratified as having “none”, “one” and “two or three” comorbidities groups. There was a significant difference between groups as determined by one-way ANOVA (<a href="#t0010" class="elsevierStyleCrossRefs">Table 2</a>). CAT scores increased from the “none” comorbidity group (17.9 ± 7.7) to “one” comorbidity group (22.8 ± 6.8) and “two or three” comorbidities group (24.2 ± 10.2). A Bonferroni post hoc test revealed a significant difference in the “none” comorbidity group compared to the “two or three” comorbidities group (p = 0.01).Table 2. Parameters of the 79 patients according to the number of comorbidity.<a name="t0010" class="elsevierStyleCrossRefs"></a><table><tr align="left"><td>Variable</td><td>Zero (36)</td><td>One (19)</td><td>Two or three (24)</td><td>p</td></tr><tr align="left"><td>Male no. (%) *</td><td>23 (33)</td><td>10 (52)</td><td>11 (45)</td><td>0.3</td></tr><tr align="left"><td>Age, years mean ± SD c</td><td>65.3 ± 7.5</td><td>68.6 ± 8.6</td><td>68.2 ± 8.2</td><td>0.3</td></tr><tr align="left"><td colspan="5"> </td></tr><tr align="left"><td colspan="5">Severity of airflow limitation no. (%) *</td></tr><tr align="left"><td>Stage II</td><td>18 (50)</td><td>7 (36)</td><td>7 (29)</td><td>0.2</td></tr><tr align="left"><td>Stage III/IV</td><td>18 (50)</td><td>12 (63)</td><td>1 (70)</td><td> </td></tr><tr align="left"><td colspan="5"> </td></tr><tr align="left"><td colspan="5">SGRQ mean ± SD c</td></tr><tr align="left"><td>Total</td><td>49.7 ± 18.1</td><td>49.9 ± 19.6</td><td>48.6 ± 19.7</td><td>0.9</td></tr><tr align="left"><td>Symptoms</td><td>44.7 ± 24.5</td><td>46.7 ± 20.4</td><td>45.9 ± 23.7</td><td>0.8</td></tr><tr align="left"><td>Activity</td><td>62.3 ± 21.9</td><td>61.7 ± 21.2</td><td>51.5 ± 21.4</td><td>0.9</td></tr><tr align="left"><td>Impact</td><td>42 ± 18.5</td><td>41.3 ± 18.6</td><td>41.6 ± 21.1</td><td>0.9</td></tr><tr align="left"><td>mMrc</td><td>2.1</td><td>2.1</td><td>2.8</td><td>0.3</td></tr><tr align="left"><td>6MWT meters, mean ± SD c</td><td>386.1 ± 83.2 a</td><td>350 ± 98</td><td>312.6 ± 91</td><td>0.007</td></tr><tr align="left"><td>CAT scores c</td><td>17.9 ± 7.7 b</td><td>22.8 ± 6.8</td><td>24.2 ± 10.2</td><td>0.019</td></tr></table>SGRQ: St. George's respiratory questionnaire, mMRC: modified medical research council dyspnea scale, 6MWT: 6-min walking test, CAT: COPD assessment test. * χ2 test for linear trends. a Significant difference between groups: no comorbidities vs more than 1 comorbidity. b Significant difference between groups: no comorbidities vs more than 1 comorbidity. c Analysis of variance with Bonferroni correction. The presence of comorbidities was associated with an increased CAT score for the items that assess the functional capacity. The score of activities items increased from 2.56 ± 1.4 for “none” comorbidity group to 3.32 ± 1.2 for “one” comorbidity group and 3.38 ± 1.5 for “two or three” comorbidities group (p = 0.04). For confidence and energy items the scores for groups “none”, “one” and “two or three” comorbidities were respectively 2.03 ± 1.1; 2.63 ± 1.2 and 3.04 ± 1.5 (p = 0.01) and 2.78 ± 1.2; 3.58 ± 1.1 and 3.67 ± 1.4 (p = 0.02).The distance walked by the patients decreased from the “none” comorbidity group (386.1 ± 83.2 m) to the “one” comorbidity group (350 ± 98 m) and “two or three” comorbidities group (312.6 ± 91 m). A Bonferroni post hoc test showed significant difference in the “none” comorbidity group compared to “two or three” comorbidities group (p = 0.007).Each one of the three specific comorbidities had a similar impact on both exercise functional capacity as in CAT score. For cardiovascular disease, hypertension or diabetes the distance walked by the patients was respectively, 315 ± 95.4 m, 330 ± 98.2 m and 313.8 ± 80.7 m (p < 0.05). The CAT scores were respectively, 23.7 ± 10.5; 23.4 ± 9.2 and 22.6 ± 9.7 (p < 0.05). Multiple linear regression analyses was built in order to investigate the influence of comorbidities on the 6MWT adjusting for age, severity of COPD and CAT scores A multiple linear regression model was built in order to investigate the influence of comorbidities in the 6MWT, after adjustment for age, severity of COPD and CAT score. The number of comorbidities was inversely associated with the distance walked during the 6MWT (<a href="#t0015" class="elsevierStyleCrossRefs">Table 3</a>).Table 3. Results of the stepwise multiple regression analyses of 79 patients with 6MWT as dependent variable.<a name="t0015" class="elsevierStyleCrossRefs"></a><table><tr align="left"><td>Outcome/predictor</td><td>Coefficient</td><td>Standard error</td><td>p-value</td><td>95% CI</td></tr><tr align="left"><td colspan="5">6MWT</td></tr><tr align="left"><td>Constant</td><td>520.5</td><td>101.6</td><td>0.000</td><td>318.7 to 722.4</td></tr><tr align="left"><td>No. of comorbidities</td><td>−23.5</td><td>10.9</td><td>0.03</td><td>−45.4 to −1.7</td></tr></table>Adjusted R2 = 0.117. 6MWT: 6-min walking test. <a name="sec0035" class="elsevierStyleCrossRefs"></a>DiscussionIn this cross-sectional study, we found that 54% of patients with COPD, before starting the pulmonary rehabilitation program, had at least one of the three searched comorbidities. In a previous study, Crisafulli et al. reported very similar results (51%).<a href="#bib58" class="elsevierStyleCrossRefs">25</a>The exercise capacity is currently considered an important parameter in the prediction of the risk of death from any cause and from respiratory causes among patients with COPD.<a href="#bib59" class="elsevierStyleCrossRefs">26</a> This study showed that the presence of one or more comorbidities is associated with reduced exercise capacity in COPD patients. Our findings corroborated a recent study showing that heart trouble, hypertension and diabetes are associated with increased breathlessness and reduced 6-min walking distance.<a href="#bib49" class="elsevierStyleCrossRefs">16</a> The assessment of exercise capacity by means of the 6MWT is frequently used in pulmonary and cardiac diseases. This is a simple, low cost and reproducible method to assess exercise capacity and it correlates closely with the daily activities of patients.<a href="#bib60" class="elsevierStyleCrossRefs">27</a>Several comorbidities are associated with COPD. Among the frequently considered as relevant are included cardiovascular diseases, hypertension, lung cancer, diabetes cerebrovascular disease, muscle weakness, osteoporosis, anxiety and depression.<a href="#bib61" class="elsevierStyleCrossRefs">28</a>Results of a large population-based study support the association between COPD and an increased incidence of cardiovascular disease.<a href="#bib62" class="elsevierStyleCrossRefs">29</a>Due to the great number and high complexity of diseases associated with COPD we could not comprehensively address all comorbidities. Instead we focused on diabetes and cardiovascular disease since they are common and are associated with an increased frequency of relevant outcomes, including mortality and hospitalizations, in patients with COPD.<a href="#bib40" class="elsevierStyleCrossRefs">7</a>The association between respiratory and cardiovascular diseases is a subject of research that has received a great deal of attention in recent years.<a href="#bib63" class="elsevierStyleCrossRefs">30</a>, <a href="#bib64" class="elsevierStyleCrossRefs">31</a>, <a href="#bib65" class="elsevierStyleCrossRefs">32</a>, <a href="#bib66" class="elsevierStyleCrossRefs">33</a> Increased systemic inflammation in COPD patients with cardiac comorbidities supports the hypothesis of systemic inflammation as a potential mechanistic link between COPD and these comorbidities.<a href="#bib61" class="elsevierStyleCrossRefs">28</a>The univariate analysis indicated that COPD subjects with one or more comorbidities had a significant higher CAT score than those without comorbidities. This is in agreement with the study of Miyazaki et al.<a href="#bib44" class="elsevierStyleCrossRefs">11</a>Burger et al.<a href="#bib60" class="elsevierStyleCrossRefs">27</a> in a cross-sectional study including 326 COPD patients, observed that anxiety and depression, but not cardiovascular disease and diabetes, are associated with low health-related quality of life assessed by SGRQ. In our study there was a lack of association of comorbidities with the SGRQ. The possible explanation is that Saint George is a specific questionnaire for respiratory diseases and does not directly evaluate “activity”, “confidence” and “energy”, items assessed in CAT and which showed strong correlation with functional exercise capacity.The severity of airflow limitation was not generally associated with comorbidities. This result is in agreement with a longitudinal study including 2164 patients, performed by Miller et al.<a href="#bib49" class="elsevierStyleCrossRefs">16</a>, that failed to show association between comorbidities and severity of airflow limitation.Some limitations of this study should be mentioned. This is a cross-sectional study with a convenience sample of patients with moderate to severe COPD. Subjects were recruited from two teaching hospitals and this may differ from COPD patients treated elsewhere. Due to the small sample size, a comparison of sub-groups GOLD stages II, III and IV, was not possible. The participants of this study were treated as considered best by their clinicians, so it was not possible to evaluate the influence of comorbidity treatment on the 6MWT.Some strengths deserve be mentioned. This study used an objective and reproducible method for the assessment of functional exercise capacity (walked distance in the 6MWT) and well-defined criteria for comorbidities. In addition, our patients were homogenously distributed as to the severity of airflow limitation.In summary, the presence of comorbidities contributed to impair functional exercise capacity in the patients studied. This finding reinforces the recommendation for a rigorous search for comorbidities in patients with COPD and functional exercise capacity impairment.<a name="sec0040" class="elsevierStyleCrossRefs"></a>Ethical disclosures<a name="sec0045" class="elsevierStyleCrossRefs"></a>Protection of human and animal subjectsThe authors declare that the procedures followed were in accordance with the regulations of the relevant clinical research ethics committee and with those of the Code of Ethics of the World Medical Association (Declaration of Helsinki).<a name="sec0050" class="elsevierStyleCrossRefs"></a>Confidentiality of dataThe authors declare that they have followed the protocols of their work center on the publication of patient data.<a name="sec0055" class="elsevierStyleCrossRefs"></a>Right to privacy and informed consentThe authors have obtained the written informed consent of the patients or subjects mentioned in the article. The corresponding author is in possession of this document.<a name="sec0060" class="elsevierStyleCrossRefs"></a>Conflicts of interestThe authors have no conflicts of interest to declare.Received 10 November 2014 Accepted 1 April 2015 Corresponding author. eanes@fortalnet.com.br" "pdfFichero" => "320v21n05a90436491pdf001.pdf" "tienePdf" => true "PalabrasClave" => array:1 [ "en" => array:1 [ 0 => array:4 [ "clase" => "keyword" "titulo" => "Keywords" "identificador" => "xpalclavsec640969" "palabras" => array:4 [ 0 => "Exercise capacity" 1 => "Health status" 2 => "COPD" 3 => "Comorbidity" ] ] ] ] "tieneResumen" => true "resumen" => array:1 [ "en" => array:1 [ "resumen" => "Background Comorbidities are common in COPD and have been associated with reduced health status, increased health care utilization, all-cause hospitalization, and mortality. There is a scarcity of data on the relationship between comorbidities and functional capacity.Objective to evaluate the impact of comorbidities on functional capacity of COPD patients.Methods a cross-sectional study was conducted at two teaching hospitals in Fortaleza, Brazil. The functional capacity was assessed by spirometry and the 6-min walking test (6MWT). The health status was assessed by the St. George's respiratory questionnaire (SGRQ) and the COPD assessment test (CAT). The sample was stratified as having “none”, “one” and “two or three” comorbidities groups. One-way ANOVA was used to compare means of the three groups and a multiple linear regression was run to predict the impact of comorbidities on 6MWT.Results Comorbidities (hypertension, coronary disease and diabetes) were found in 54% of the studied patients. The mean age of the 79 patients was 67 ± 8 years and 55% were male. CAT scores increased from “no comorbidity” (17.9 ± 7.7) to “one comorbidity” (22.8 ± 6.8) and “two or three comorbidities” groups (24.2 ± 10.2). A post hoc test showed a significant difference in the “no comorbidity” compared to the “two or three comorbidities” groups (p = 0.01). The distance walked by the patients decreased from “no comorbidity” (386.1 ± 83.2 m) to “one comorbidity” (350 ± 98 m) and “two or three comorbidities” groups (312.6 ± 91 m). A post hoc test showed significant difference in the “no comorbidity” compared to “two or three comorbidities” groups (p = 0.007). Numbers of comorbidities were independently associated with the 6MWT adjusting for age, severity of COPD and CAT scores.Conclusion in the studied sample, the presence of comorbidities contributed to impair exercise capacity in patients with COPD." ] ] "bibliografia" => array:2 [ "titulo" => "Bibliography" "seccion" => array:1 [ 0 => array:1 [ "bibliografiaReferencia" => array:33 [ 0 => array:3 [ "identificador" => "bib34" "etiqueta" => "1" "referencia" => array:1 [ 0 => array:3 [ "referenciaCompleta" => "Optimizing economic outcomes in the management of COPD. Int J Chron Obstr Pulm Dis. 2008; 3:1-10." "contribucion" => array:1 [ 0 => array:3 [ "titulo" => "Optimizing economic outcomes in the management of COPD." "idioma" => "en" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:1 [ 0 => "Dal Negro R." ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "Int J Chron Obstr Pulm Dis. 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G.P.F. Da Silvaa,b, M.T.A. Pessoa Moranoc, A.G. De Matos Cavalcantea, N.M.. De Andradea, E. De Francesco Dahera, E.D.B. Pereiraa,

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eanes@fortalnet.com.br

Corresponding author. eanes@fortalnet.com.br

a Universidade Federal do Ceará – UFC, Fortaleza, Brazil

b Universidade de Fortaleza – UNIFOR, Fortaleza, Brazil

c Hospital de Messejana Dr. Carlos Alberto Studart Gomes, Fortaleza, Brazil

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    "textoCompleto" => "<a name="sec0005" class="elsevierStyleCrossRefs"></a><span class="elsevierStyleSectionTitle">Introduction</span><p class="elsevierStylePara">Chronic obstructive pulmonary disease &#40;COPD&#41; is an important cause of impaired health-related quality of life&#44; disability and death&#44; with expressive social and economic repercussions&#46;<a href="&#35;bib34" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">1</span></a> It is a complex disease with pulmonary and systemic symptoms&#44; frequently associated with comorbidities<a href="&#35;bib35" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">2</span></a> that contribute to reduced health status and increased healthcare utilization&#44; all-cause hospital admission&#44; and mortality&#46;<a href="&#35;bib36" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">3</span></a><span class="elsevierStyleSup">&#44; </span><a href="&#35;bib37" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">4</span></a> The prevalence of the different types of comorbidity varies somewhat across studies&#44; depending on the patient population&#44; the definition of diseases and methods of patient evaluation&#46;<a href="&#35;bib38" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">5</span></a></p><p class="elsevierStylePara">Hypertension&#44; coronary disease and diabetes are frequent conditions associated with COPD and an increased risk of death&#46;<a href="&#35;bib39" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">6</span></a><span class="elsevierStyleSup">&#44; </span><a href="&#35;bib40" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">7</span></a> The presence of these comorbidities appears to have a deleterious effect on several outcomes in COPD&#46;<a href="&#35;bib38" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">5</span></a></p><p class="elsevierStylePara">Endothelial dysfunction and increased arterial stiffness begin early in the course of COPD<a href="&#35;bib41" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">8</span></a><span class="elsevierStyleSup">&#44; </span><a href="&#35;bib42" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">9</span></a><span class="elsevierStyleSup">&#44; </span><a href="&#35;bib43" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">10</span></a> and probably represent the onset of atherosclerotic disease&#46; Data from one study&#44; including 20&#44;269 subjects&#44; identified a 40&#37; prevalence of hypertension among 76 patients with COPD&#46;<a href="&#35;bib40" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">7</span></a> Results from an observational study suggests that poorer health status&#44; as indicated by a high COPD assessment test &#40;CAT&#41; score&#44; may indicate the presence of certain comorbidities&#46;<a href="&#35;bib44" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">11</span></a></p><p class="elsevierStylePara">There is a growing body of evidence from some studies evaluating the impact of comorbidities on 6-min walking test &#40;6MWT&#41;&#46; Most of these studies have included patients with anxiety and depression&#46;<a href="&#35;bib45" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">12</span></a><span class="elsevierStyleSup">&#44; </span><a href="&#35;bib46" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">13</span></a><span class="elsevierStyleSup">&#44; </span><a href="&#35;bib47" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">14</span></a><span class="elsevierStyleSup">&#44; </span><a href="&#35;bib48" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">15</span></a> Only one observational and longitudinal study has included 2164 patients with COPD associated with diabetes and cardiovascular disease&#46;<a href="&#35;bib49" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">16</span></a></p><p class="elsevierStylePara">A better understanding of the impact of comorbidities&#44; particularly diabetes&#44; hypertension and cardiovascular disease&#44; among patients with COPD is required&#46; In the current study&#44; we have evaluated the impact of comorbidities&#44; diabetes&#44; hypertension and cardiovascular disease&#44; on functional performance in patients with COPD&#44; after controlling for the effects of potential confounders including age&#44; severity of COPD and health status&#46;</p><a name="sec0010" class="elsevierStyleCrossRefs"></a><span class="elsevierStyleSectionTitle">Methods</span><a name="sec0015" class="elsevierStyleCrossRefs"></a><span class="elsevierStyleSectionTitle">Patients and study design</span><p class="elsevierStylePara">A cross-sectional study was conducted at two teaching hospitals in Fortaleza&#44; Brazil&#44; from January to December 2012&#46; The research protocol was approved by local Research Ethics Committee &#40;no&#46; 880&#47;12&#41;&#44; and a written informed consent was obtained in all 96 cases&#46; Patients were recruited during their initial assessment prior to enrollment in a 97 pulmonary rehabilitation program in the ambulatories of both hospitals&#46; The inclusion criteria were&#44; to be smoker or ex-smoker with a smoking history of at least 10 packs-years&#44; aged 40&#8211;80 years&#44; a previous diagnosis of COPD on stages II&#8211;IV &#40;post-bronchodilator FEV1&#47;FVC&#160;&#60;&#160;0&#46;7 and FEV1&#160;&#60;&#160;80&#37; of predicted&#41;&#46; All patients were clinically stable and without exacerbations for at least one month prior to recruitment&#46;</p><p class="elsevierStylePara">Patients with a primary diagnosis of asthma or other chronic respiratory diseases&#44; with severe cognitive deficiency preventing them from understanding the questionnaire and patients with restricted mobility&#44; were excluded&#46;</p><a name="sec0020" class="elsevierStyleCrossRefs"></a><span class="elsevierStyleSectionTitle">Assessment of patient&#39;s parameters</span><p class="elsevierStylePara">Socio-demographic data were obtained through a structured questionnaire&#46; Functional capacity was assessed by spirometry and 6MWT&#46; The time allowed for patients to rest between the two tests was 1&#160;h&#46;</p><p class="elsevierStylePara">Spirometry was conducted using an electronic spirometer in accordance with the guidelines of the American Thoracic Society&#47;European Respiratory Society &#40;ATS&#47;ERS&#41;&#46;<a href="&#35;bib50" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">17</span></a></p><p class="elsevierStylePara">Functional exercise capacity was assessed by 6MWT&#46; It was performed twice in a 30&#160;m corridor&#46; The patients were instructed to walk from end to end&#44; covering as much ground as they could during the allotted time&#44; as recommended by ATS guidelines&#46;<a href="&#35;bib51" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">18</span></a></p><p class="elsevierStylePara">Health-related quality of life was assessed by St&#46; George&#39;s respiratory questionnaire &#40;SGRQ&#41;&#46; The SGRQ consists of 53 items&#44; which can be aggregated into an overall score and three domain scores describing symptoms&#44; activity and impact&#46;<a href="&#35;bib52" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">19</span></a> Current health was assessed by the COPD assessment test &#40;CAT&#41;&#46; This questionnaire consists of eight items that describe cough&#44; phlegm&#44; chest tightness&#44; breathlessness going up hills&#47;stairs&#44; activity limitations at home&#44; confidence leaving home&#44; sleep and energy&#46; Each item is scored from 0 to 5&#44; thereby making the range of the total score from 0 to 40&#46; Higher scores represent worse health&#46;<a href="&#35;bib53" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">20</span></a> Both&#44; SGRQ and CAT were previously translated and validated for the Portuguese language&#46;<a href="&#35;bib54" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">21</span></a><span class="elsevierStyleSup">&#44; </span><a href="&#35;bib55" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">22</span></a><span class="elsevierStyleSup">&#44; </span><a href="&#35;bib56" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">23</span></a> The Brazilian version of SGRQ and CAT showed good psychometric properties&#46; CAT showed an excellent inter-rater and intra-rater reliability &#40;intraclass correlation coefficient &#91;ICC&#93;&#160;&#61;&#160;0&#46;96&#59; 95&#37; CI&#58; 0&#46;93&#8211;0&#46;97&#59; <span class="elsevierStyleItalic">p</span>&#160;&#60;&#160;0&#46;001&#59; and ICC&#160;&#61;&#160;0&#46;98&#59; 95&#37; CI&#58; 0&#46;96&#8211;0&#46;98&#59; <span class="elsevierStyleItalic">p</span>&#160;&#60;&#160;0&#46;001&#44; respectively&#41;&#46;<a href="&#35;bib56" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">23</span></a> SGRQ showed an intraclass correlation ratio for the total score of <span class="elsevierStyleItalic">&#945;</span>&#160;&#61;&#160;0&#46;79&#46;<a href="&#35;bib54" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">21</span></a> Both questionnaires were administered in the mode of face-to-face interview&#44; by the same interviewer and prior to the start of the rehabilitation program&#46;</p><p class="elsevierStylePara">The diagnosis of the three studied comorbidities was based on data from medical records or upon clinical examination of patients&#46; Subjects were classified as having diabetes if they reported a physician diagnosis of diabetes at baseline&#44; or had impaired fasting or post-glucose load glucose levels &#40;&#8805;140&#160;mg&#160;dL<span class="elsevierStyleSup">&#8722;1</span>&#41; upon examination&#46;</p><p class="elsevierStylePara">Subjects were classified as having coronary disease if they reported a previous physician diagnosis of myocardial infarction&#44; angina or transient ischemic attacks&#44; or when this information was registered in their medical records&#46;</p><p class="elsevierStylePara">Subjects were classified as having hypertension if they reported a physician diagnosis of hypertension&#44; were taking drugs for hypertension or had evidence of hypertension during a clinical examination &#40;diastolic blood pressure &#8805;90&#160;mmHg or a systolic blood pressure &#8805;140&#160;mmHg&#44; on three measurements&#41;&#46; Each subject was classified as having none&#44; one&#44; two or three comorbidities&#46;</p><a name="sec0025" class="elsevierStyleCrossRefs"></a><span class="elsevierStyleSectionTitle">Statistical analyses</span><p class="elsevierStylePara">For continuous variables&#44; data are presented as means&#160;&#177;&#160;standard deviation &#40;SD&#41; and for categorical variables&#44; as percentage&#46; Normality distribution for continuous variables was assessed by means of the Kolmogorov&#8211;Smirnov test&#46; One-way ANOVA with the Bonferroni correction was used to compare the means of the three groups&#46; For comparison of proportions&#44; the &#967;<span class="elsevierStyleSup">2</span> test for linear trends was used&#46; A multiple linear regression was run to predict the impact of comorbidities on 6MWT adjusting for age&#44; severity of COPD and CAT scores&#46; The <span class="elsevierStyleItalic">p</span> values less than 0&#46;05 were considered significant&#46; All statistical analyses were performed with SPSS for Windows version 10&#46;0 &#40;SPSS Inc&#46;&#44; Chicago&#44; IL&#41;&#46;</p><a name="sec0030" class="elsevierStyleCrossRefs"></a><span class="elsevierStyleSectionTitle">Results</span><p class="elsevierStylePara">Demographic&#44; clinical&#44; respiratory function and functional exercise capacity of the 79 subjects studied are shown in <a href="&#35;t0005" class="elsevierStyleCrossRefs">Table 1</a>&#46; According the new GOLD classification &#40;GOLD 2014&#41;&#44;<a href="&#35;bib57" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">24</span></a> 4 &#40;5&#37;&#41; patients were in grade A&#44; 26 &#40;32&#46;9&#37;&#41; in grade B&#44; 7 &#40;8&#46;8&#37;&#41; in grade C and 42 &#40;53&#37;&#41; in grade D&#46;</p><p class="elsevierStylePara">Table 1&#46; Demographic&#44; clinical and functional characteristics of 79 COPD patients&#46;</p><a name="t0005" class="elsevierStyleCrossRefs"></a><p class="elsevierStylePara"></p><table><tr align="left"><td>Variable</td><td>COPD patients &#40;79&#41;</td></tr><tr align="left"><td colspan="2">Gender no &#40;&#37;&#41;</td></tr><tr align="left"><td>Male</td><td>44 &#40;56&#37;&#41;</td></tr><tr align="left"><td>Female</td><td>35 &#40;44&#37;&#41;</td></tr><tr align="left"><td>Age&#44; years mean&#160;&#177;&#160;SD</td><td>67&#160;&#177;&#160;8</td></tr><tr align="left"><td colspan="2">&#160;</td></tr><tr align="left"><td colspan="2">COPD classification <span class="elsevierStyleItalic">n</span> &#40;&#37;&#41;</td></tr><tr align="left"><td>Grade A</td><td>4 &#40;5&#37;&#41;</td></tr><tr align="left"><td>Grade B</td><td>26 &#40;32&#46;9&#37;&#41;</td></tr><tr align="left"><td>Grade C</td><td>7 &#40;8&#46;8&#37;&#41;</td></tr><tr align="left"><td>Grade D</td><td>42 &#40;53&#37;&#41;</td></tr><tr align="left"><td>FEV1 &#40;&#37;&#41; mean&#160;&#177;&#160;SD</td><td>45&#46;5&#160;&#177;&#160;13&#46;2</td></tr><tr align="left"><td>FEV1 &#40;l&#41; mean&#160;&#177;&#160;SD</td><td>1&#46;06&#160;&#177;&#160;0&#46;377</td></tr><tr align="left"><td>FVC &#40;&#37;&#41; mean&#160;&#177;&#160;SD</td><td>73&#46;1&#160;&#177;&#160;16&#46;5</td></tr><tr align="left"><td>FVC &#40;l&#41; mean&#160;&#177;&#160;SD</td><td>2&#46;17&#160;&#177;&#160;0&#46;694</td></tr><tr align="left"><td colspan="2">&#160;</td></tr><tr align="left"><td colspan="2">SGRQ mean&#160;&#177;&#160;SD</td></tr><tr align="left"><td>Total mean&#160;&#177;&#160;SD</td><td>49&#46;4&#160;&#177;&#160;18</td></tr><tr align="left"><td>Symptoms mean&#160;&#177;&#160;SD</td><td>45&#46;5&#160;&#177;&#160;22&#46;9</td></tr><tr align="left"><td>Activity mean&#160;&#177;&#160;SD</td><td>61&#160;&#177;&#160;23&#46;1</td></tr><tr align="left"><td>Impact mean&#160;&#177;&#160;SD</td><td>41&#46;7&#160;&#177;&#160;19&#46;8</td></tr><tr align="left"><td>6MWT meters&#44; mean&#160;&#177;&#160;SD</td><td>355&#160;&#177;&#160;93&#46;8</td></tr><tr align="left"><td colspan="2">&#160;</td></tr><tr align="left"><td colspan="2">Comorbidities</td></tr><tr align="left"><td>Total</td><td>43 &#40;54&#37;&#41;</td></tr><tr align="left"><td>Hypertension</td><td>39 &#40;49&#37;&#41;</td></tr><tr align="left"><td>Diabetes</td><td>14 &#40;17&#37;&#41;</td></tr><tr align="left"><td>Coronary disease</td><td>19 &#40;24&#37;&#41;</td></tr><tr align="left"><td colspan="2">&#160;</td></tr><tr align="left"><td colspan="2">Numbers of comorbidity</td></tr><tr align="left"><td>zero</td><td>36 &#40;45&#37;&#41;</td></tr><tr align="left"><td>One</td><td>19 &#40;24&#37;&#41;</td></tr><tr align="left"><td>Two or three</td><td>24 &#40;30&#37;&#41;</td></tr></table><p class="elsevierStylePara">The mean age of the patients was 67&#160;&#177;&#160;8 years and 44 &#40;55&#37;&#41; were male&#46; Fifty four percent of patients had at least one of three studied comorbidities&#46; The sample was stratified as having &#8220;none&#8221;&#44; &#8220;one&#8221; and &#8220;two or three&#8221; comorbidities groups&#46; There was a significant difference between groups as determined by one-way ANOVA &#40;<a href="&#35;t0010" class="elsevierStyleCrossRefs">Table 2</a>&#41;&#46; CAT scores increased from the &#8220;none&#8221; comorbidity group &#40;17&#46;9&#160;&#177;&#160;7&#46;7&#41; to &#8220;one&#8221; comorbidity group &#40;22&#46;8&#160;&#177;&#160;6&#46;8&#41; and &#8220;two or three&#8221; comorbidities group &#40;24&#46;2&#160;&#177;&#160;10&#46;2&#41;&#46; A Bonferroni post hoc test revealed a significant difference in the &#8220;none&#8221; comorbidity group compared to the &#8220;two or three&#8221; comorbidities group &#40;<span class="elsevierStyleItalic">p</span>&#160;&#61;&#160;0&#46;01&#41;&#46;</p><p class="elsevierStylePara">Table 2&#46; Parameters of the 79 patients according to the number of comorbidity&#46;</p><a name="t0010" class="elsevierStyleCrossRefs"></a><p class="elsevierStylePara"></p><table><tr align="left"><td>Variable</td><td>Zero &#40;36&#41;</td><td>One &#40;19&#41;</td><td>Two or three &#40;24&#41;</td><td><span class="elsevierStyleItalic">p</span></td></tr><tr align="left"><td>Male no&#46; &#40;&#37;&#41;  <span class="elsevierStyleSup">&#42;</span></td><td>23 &#40;33&#41;</td><td>10 &#40;52&#41;</td><td>11 &#40;45&#41;</td><td>0&#46;3</td></tr><tr align="left"><td>Age&#44; years mean&#160;&#177;&#160;SD  <span class="elsevierStyleSup">c</span></td><td>65&#46;3&#160;&#177;&#160;7&#46;5</td><td>68&#46;6&#160;&#177;&#160;8&#46;6</td><td>68&#46;2&#160;&#177;&#160;8&#46;2</td><td>0&#46;3</td></tr><tr align="left"><td colspan="5">&#160;</td></tr><tr align="left"><td colspan="5">Severity of airflow limitation no&#46; &#40;&#37;&#41;  <span class="elsevierStyleSup">&#42;</span></td></tr><tr align="left"><td>Stage II</td><td>18 &#40;50&#41;</td><td>7 &#40;36&#41;</td><td>7 &#40;29&#41;</td><td>0&#46;2</td></tr><tr align="left"><td>Stage III&#47;IV</td><td>18 &#40;50&#41;</td><td>12 &#40;63&#41;</td><td>1 &#40;70&#41;</td><td>&#160;</td></tr><tr align="left"><td colspan="5">&#160;</td></tr><tr align="left"><td colspan="5">SGRQ mean&#160;&#177;&#160;SD  <span class="elsevierStyleSup">c</span></td></tr><tr align="left"><td>Total</td><td>49&#46;7&#160;&#177;&#160;18&#46;1</td><td>49&#46;9&#160;&#177;&#160;19&#46;6</td><td>48&#46;6&#160;&#177;&#160;19&#46;7</td><td>0&#46;9</td></tr><tr align="left"><td>Symptoms</td><td>44&#46;7&#160;&#177;&#160;24&#46;5</td><td>46&#46;7&#160;&#177;&#160;20&#46;4</td><td>45&#46;9&#160;&#177;&#160;23&#46;7</td><td>0&#46;8</td></tr><tr align="left"><td>Activity</td><td>62&#46;3&#160;&#177;&#160;21&#46;9</td><td>61&#46;7&#160;&#177;&#160;21&#46;2</td><td>51&#46;5&#160;&#177;&#160;21&#46;4</td><td>0&#46;9</td></tr><tr align="left"><td>Impact</td><td>42&#160;&#177;&#160;18&#46;5</td><td>41&#46;3&#160;&#177;&#160;18&#46;6</td><td>41&#46;6&#160;&#177;&#160;21&#46;1</td><td>0&#46;9</td></tr><tr align="left"><td>mMrc</td><td>2&#46;1</td><td>2&#46;1</td><td>2&#46;8</td><td>0&#46;3</td></tr><tr align="left"><td>6MWT meters&#44; mean&#160;&#177;&#160;SD  <span class="elsevierStyleSup">c</span></td><td>386&#46;1&#160;&#177;&#160;83&#46;2  <span class="elsevierStyleSup">a</span></td><td>350&#160;&#177;&#160;98</td><td>312&#46;6&#160;&#177;&#160;91</td><td>0&#46;007</td></tr><tr align="left"><td>CAT scores  <span class="elsevierStyleSup">c</span></td><td>17&#46;9&#160;&#177;&#160;7&#46;7  <span class="elsevierStyleSup">b</span></td><td>22&#46;8&#160;&#177;&#160;6&#46;8</td><td>24&#46;2&#160;&#177;&#160;10&#46;2</td><td>0&#46;019</td></tr></table><p class="elsevierStylePara">SGRQ&#58; St&#46; George&#39;s respiratory questionnaire&#44; mMRC&#58; modified medical research council dyspnea scale&#44; 6MWT&#58; 6-min walking test&#44; CAT&#58; COPD assessment test&#46;<br></br></p><p class="elsevierStylePara">&#42; <span class="elsevierStyleItalic">&#967;</span><span class="elsevierStyleSup">2</span> test for linear trends&#46;<br></br>a Significant difference between groups&#58; no comorbidities vs more than 1 comorbidity&#46;<br></br>b Significant difference between groups&#58; no comorbidities vs more than 1 comorbidity&#46;<br></br>c Analysis of variance with Bonferroni correction&#46;<br></br></p><p class="elsevierStylePara">The presence of comorbidities was associated with an increased CAT score for the items that assess the functional capacity&#46; The score of activities items increased from 2&#46;56&#160;&#177;&#160;1&#46;4 for &#8220;none&#8221; comorbidity group to 3&#46;32&#160;&#177;&#160;1&#46;2 for &#8220;one&#8221; comorbidity group and 3&#46;38&#160;&#177;&#160;1&#46;5 for &#8220;two or three&#8221; comorbidities group &#40;<span class="elsevierStyleItalic">p</span>&#160;&#61;&#160;0&#46;04&#41;&#46; For confidence and energy items the scores for groups &#8220;none&#8221;&#44; &#8220;one&#8221; and &#8220;two or three&#8221; comorbidities were respectively 2&#46;03&#160;&#177;&#160;1&#46;1&#59; 2&#46;63&#160;&#177;&#160;1&#46;2 and 3&#46;04&#160;&#177;&#160;1&#46;5 &#40;<span class="elsevierStyleItalic">p</span>&#160;&#61;&#160;0&#46;01&#41; and 2&#46;78&#160;&#177;&#160;1&#46;2&#59; 3&#46;58&#160;&#177;&#160;1&#46;1 and 3&#46;67&#160;&#177;&#160;1&#46;4 &#40;<span class="elsevierStyleItalic">p</span>&#160;&#61;&#160;0&#46;02&#41;&#46;</p><p class="elsevierStylePara">The distance walked by the patients decreased from the &#8220;none&#8221; comorbidity group &#40;386&#46;1&#160;&#177;&#160;83&#46;2&#160;m&#41; to the &#8220;one&#8221; comorbidity group &#40;350&#160;&#177;&#160;98&#160;m&#41; and &#8220;two or three&#8221; comorbidities group &#40;312&#46;6&#160;&#177;&#160;91&#160;m&#41;&#46; A Bonferroni post hoc test showed significant difference in the &#8220;none&#8221; comorbidity group compared to &#8220;two or three&#8221; comorbidities group &#40;<span class="elsevierStyleItalic">p</span>&#160;&#61;&#160;0&#46;007&#41;&#46;</p><p class="elsevierStylePara">Each one of the three specific comorbidities had a similar impact on both exercise functional capacity as in CAT score&#46; For cardiovascular disease&#44; hypertension or diabetes the distance walked by the patients was respectively&#44; 315&#160;&#177;&#160;95&#46;4&#160;m&#44; 330&#160;&#177;&#160;98&#46;2&#160;m and 313&#46;8&#160;&#177;&#160;80&#46;7&#160;m &#40;<span class="elsevierStyleItalic">p</span>&#160;&#60;&#160;0&#46;05&#41;&#46; The CAT scores were respectively&#44; 23&#46;7&#160;&#177;&#160;10&#46;5&#59; 23&#46;4&#160;&#177;&#160;9&#46;2 and 22&#46;6&#160;&#177;&#160;9&#46;7 &#40;<span class="elsevierStyleItalic">p</span>&#160;&#60;&#160;0&#46;05&#41;&#46; Multiple linear regression analyses was built in order to investigate the influence of comorbidities on the 6MWT adjusting for age&#44; severity of COPD and CAT scores A multiple linear regression model was built in order to investigate the influence of comorbidities in the 6MWT&#44; after adjustment for age&#44; severity of COPD and CAT score&#46; The number of comorbidities was inversely associated with the distance walked during the 6MWT &#40;<a href="&#35;t0015" class="elsevierStyleCrossRefs">Table 3</a>&#41;&#46;</p><p class="elsevierStylePara">Table 3&#46; Results of the stepwise multiple regression analyses of 79 patients with 6MWT as dependent variable&#46;</p><a name="t0015" class="elsevierStyleCrossRefs"></a><p class="elsevierStylePara"></p><table><tr align="left"><td>Outcome&#47;predictor</td><td>Coefficient</td><td>Standard error</td><td><span class="elsevierStyleItalic">p</span>-value</td><td>95&#37; CI</td></tr><tr align="left"><td colspan="5">6MWT</td></tr><tr align="left"><td>Constant</td><td>520&#46;5</td><td>101&#46;6</td><td>0&#46;000</td><td>318&#46;7 to 722&#46;4</td></tr><tr align="left"><td>No&#46; of comorbidities</td><td>&#8722;23&#46;5</td><td>10&#46;9</td><td>0&#46;03</td><td>&#8722;45&#46;4 to &#8722;1&#46;7</td></tr></table><p class="elsevierStylePara">Adjusted <span class="elsevierStyleItalic">R</span><span class="elsevierStyleSup">2</span>&#160;&#61;&#160;0&#46;117&#46;<br></br>6MWT&#58; 6-min walking test&#46;<br></br></p><a name="sec0035" class="elsevierStyleCrossRefs"></a><span class="elsevierStyleSectionTitle">Discussion</span><p class="elsevierStylePara">In this cross-sectional study&#44; we found that 54&#37; of patients with COPD&#44; before starting the pulmonary rehabilitation program&#44; had at least one of the three searched comorbidities&#46; In a previous study&#44; Crisafulli et al&#46; reported very similar results &#40;51&#37;&#41;&#46;<a href="&#35;bib58" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">25</span></a></p><p class="elsevierStylePara">The exercise capacity is currently considered an important parameter in the prediction of the risk of death from any cause and from respiratory causes among patients with COPD&#46;<a href="&#35;bib59" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">26</span></a> This study showed that the presence of one or more comorbidities is associated with reduced exercise capacity in COPD patients&#46; Our findings corroborated a recent study showing that heart trouble&#44; hypertension and diabetes are associated with increased breathlessness and reduced 6-min walking distance&#46;<a href="&#35;bib49" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">16</span></a> The assessment of exercise capacity by means of the 6MWT is frequently used in pulmonary and cardiac diseases&#46; This is a simple&#44; low cost and reproducible method to assess exercise capacity and it correlates closely with the daily activities of patients&#46;<a href="&#35;bib60" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">27</span></a></p><p class="elsevierStylePara">Several comorbidities are associated with COPD&#46; Among the frequently considered as relevant are included cardiovascular diseases&#44; hypertension&#44; lung cancer&#44; diabetes cerebrovascular disease&#44; muscle weakness&#44; osteoporosis&#44; anxiety and depression&#46;<a href="&#35;bib61" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">28</span></a></p><p class="elsevierStylePara">Results of a large population-based study support the association between COPD and an increased incidence of cardiovascular disease&#46;<a href="&#35;bib62" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">29</span></a></p><p class="elsevierStylePara">Due to the great number and high complexity of diseases associated with COPD we could not comprehensively address all comorbidities&#46; Instead we focused on diabetes and cardiovascular disease since they are common and are associated with an increased frequency of relevant outcomes&#44; including mortality and hospitalizations&#44; in patients with COPD&#46;<a href="&#35;bib40" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">7</span></a></p><p class="elsevierStylePara">The association between respiratory and cardiovascular diseases is a subject of research that has received a great deal of attention in recent years&#46;<a href="&#35;bib63" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">30</span></a><span class="elsevierStyleSup">&#44; </span><a href="&#35;bib64" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">31</span></a><span class="elsevierStyleSup">&#44; </span><a href="&#35;bib65" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">32</span></a><span class="elsevierStyleSup">&#44; </span><a href="&#35;bib66" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">33</span></a> Increased systemic inflammation in COPD patients with cardiac comorbidities supports the hypothesis of systemic inflammation as a potential mechanistic link between COPD and these comorbidities&#46;<a href="&#35;bib61" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">28</span></a></p><p class="elsevierStylePara">The univariate analysis indicated that COPD subjects with one or more comorbidities had a significant higher CAT score than those without comorbidities&#46; This is in agreement with the study of Miyazaki et al&#46;<a href="&#35;bib44" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">11</span></a></p><p class="elsevierStylePara">Burger et al&#46;<a href="&#35;bib60" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">27</span></a> in a cross-sectional study including 326 COPD patients&#44; observed that anxiety and depression&#44; but not cardiovascular disease and diabetes&#44; are associated with low health-related quality of life assessed by SGRQ&#46; In our study there was a lack of association of comorbidities with the SGRQ&#46; The possible explanation is that Saint George is a specific questionnaire for respiratory diseases and does not directly evaluate &#8220;activity&#8221;&#44; &#8220;confidence&#8221; and &#8220;energy&#8221;&#44; items assessed in CAT and which showed strong correlation with functional exercise capacity&#46;</p><p class="elsevierStylePara">The severity of airflow limitation was not generally associated with comorbidities&#46; This result is in agreement with a longitudinal study including 2164 patients&#44; performed by Miller et al&#46;<a href="&#35;bib49" class="elsevierStyleCrossRefs"><span class="elsevierStyleSup">16</span></a>&#44; that failed to show association between comorbidities and severity of airflow limitation&#46;</p><p class="elsevierStylePara">Some limitations of this study should be mentioned&#46; This is a cross-sectional study with a convenience sample of patients with moderate to severe COPD&#46; Subjects were recruited from two teaching hospitals and this may differ from COPD patients treated elsewhere&#46; Due to the small sample size&#44; a comparison of sub-groups GOLD stages II&#44; III and IV&#44; was not possible&#46; The participants of this study were treated as considered best by their clinicians&#44; so it was not possible to evaluate the influence of comorbidity treatment on the 6MWT&#46;</p><p class="elsevierStylePara">Some strengths deserve be mentioned&#46; This study used an objective and reproducible method for the assessment of functional exercise capacity &#40;walked distance in the 6MWT&#41; and well-defined criteria for comorbidities&#46; In addition&#44; our patients were homogenously distributed as to the severity of airflow limitation&#46;</p><p class="elsevierStylePara">In summary&#44; the presence of comorbidities contributed to impair functional exercise capacity in the patients studied&#46; This finding reinforces the recommendation for a rigorous search for comorbidities in patients with COPD and functional exercise capacity impairment&#46;</p><a name="sec0040" class="elsevierStyleCrossRefs"></a><span class="elsevierStyleSectionTitle">Ethical disclosures</span><a name="sec0045" class="elsevierStyleCrossRefs"></a><span class="elsevierStyleSectionTitle">Protection of human and animal subjects</span><p class="elsevierStylePara">The authors declare that the procedures followed were in accordance with the regulations of the relevant clinical research ethics committee and with those of the Code of Ethics of the World Medical Association &#40;Declaration of Helsinki&#41;&#46;</p><a name="sec0050" class="elsevierStyleCrossRefs"></a><span class="elsevierStyleSectionTitle">Confidentiality of data</span><p class="elsevierStylePara">The authors declare that they have followed the protocols of their work center on the publication of patient data&#46;</p><a name="sec0055" class="elsevierStyleCrossRefs"></a><span class="elsevierStyleSectionTitle">Right to privacy and informed consent</span><p class="elsevierStylePara">The authors have obtained the written informed consent of the patients or subjects mentioned in the article&#46; The corresponding author is in possession of this document&#46;</p><a name="sec0060" class="elsevierStyleCrossRefs"></a><span class="elsevierStyleSectionTitle">Conflicts of interest</span><p class="elsevierStylePara">The authors have no conflicts of interest to declare&#46;</p><p class="elsevierStylePara">Received 10 November 2014 <br></br>Accepted 1 April 2015 </p><p class="elsevierStylePara">Corresponding author&#46; eanes&#64;fortalnet&#46;com&#46;br</p>"
    "pdfFichero" => "320v21n05a90436491pdf001.pdf"
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        0 => array:4 [
          "clase" => "keyword"
          "titulo" => "Keywords"
          "identificador" => "xpalclavsec640969"
          "palabras" => array:4 [
            0 => "Exercise capacity"
            1 => "Health status"
            2 => "COPD"
            3 => "Comorbidity"
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        "resumen" => "<span class="elsevierStyleSectionTitle">Background</span><br/><p class="elsevierStylePara">Comorbidities are common in COPD and have been associated with reduced health status&#44; increased health care utilization&#44; all-cause hospitalization&#44; and mortality&#46; There is a scarcity of data on the relationship between comorbidities and functional capacity&#46;</p><span class="elsevierStyleSectionTitle">Objective</span><br/><p class="elsevierStylePara">to evaluate the impact of comorbidities on functional capacity of COPD patients&#46;</p><span class="elsevierStyleSectionTitle">Methods</span><br/><p class="elsevierStylePara">a cross-sectional study was conducted at two teaching hospitals in Fortaleza&#44; Brazil&#46; The functional capacity was assessed by spirometry and the 6-min walking test &#40;6MWT&#41;&#46; The health status was assessed by the St&#46; George&#39;s respiratory questionnaire &#40;SGRQ&#41; and the COPD assessment test &#40;CAT&#41;&#46; The sample was stratified as having &#8220;none&#8221;&#44; &#8220;one&#8221; and &#8220;two or three&#8221; comorbidities groups&#46; One-way ANOVA was used to compare means of the three groups and a multiple linear regression was run to predict the impact of comorbidities on 6MWT&#46;</p><span class="elsevierStyleSectionTitle">Results</span><br/><p class="elsevierStylePara">Comorbidities &#40;hypertension&#44; coronary disease and diabetes&#41; were found in 54&#37; of the studied patients&#46; The mean age of the 79 patients was 67&#160;&#177;&#160;8 years and 55&#37; were male&#46; CAT scores increased from &#8220;no comorbidity&#8221; &#40;17&#46;9&#160;&#177;&#160;7&#46;7&#41; to &#8220;one comorbidity&#8221; &#40;22&#46;8&#160;&#177;&#160;6&#46;8&#41; and &#8220;two or three comorbidities&#8221; groups &#40;24&#46;2&#160;&#177;&#160;10&#46;2&#41;&#46; A post hoc test showed a significant difference in the &#8220;no comorbidity&#8221; compared to the &#8220;two or three comorbidities&#8221; groups &#40;<span class="elsevierStyleItalic">p</span>&#160;&#61;&#160;0&#46;01&#41;&#46; The distance walked by the patients decreased from &#8220;no comorbidity&#8221; &#40;386&#46;1&#160;&#177;&#160;83&#46;2&#160;m&#41; to &#8220;one comorbidity&#8221; &#40;350&#160;&#177;&#160;98&#160;m&#41; and &#8220;two or three comorbidities&#8221; groups &#40;312&#46;6&#160;&#177;&#160;91&#160;m&#41;&#46; A post hoc test showed significant difference in the &#8220;no comorbidity&#8221; compared to &#8220;two or three comorbidities&#8221; groups &#40;<span class="elsevierStyleItalic">p</span>&#160;&#61;&#160;0&#46;007&#41;&#46; Numbers of comorbidities were independently associated with the 6MWT adjusting for age&#44; severity of COPD and CAT scores&#46;</p><span class="elsevierStyleSectionTitle">Conclusion</span><br/><p class="elsevierStylePara">in the studied sample&#44; the presence of comorbidities contributed to impair exercise capacity in patients with COPD&#46;</p>"
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Article information

ISSN: 08732159
Original language: English

DOI:10.1016/j.rppnen.2015.04.003

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Year/Month	Html	Pdf	Total

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2023 September	43	35	78
2023 August	46	16	62
2023 July	48	29	77
2023 June	45	12	57
2023 May	77	31	108
2023 April	59	25	84
2023 March	130	21	151
2023 February	87	33	120
2023 January	46	21	67
2022 December	72	17	89
2022 November	118	46	164
2022 October	99	34	133
2022 September	67	29	96
2022 August	70	36	106
2022 July	65	48	113
2022 June	51	34	85
2022 May	65	45	110
2022 April	55	36	91
2022 March	82	56	138
2022 February	88	37	125
2022 January	76	34	110
2021 December	50	42	92
2021 November	51	37	88
2021 October	67	58	125
2021 September	45	22	67
2021 August	55	27	82
2021 July	65	24	89
2021 June	78	29	107
2021 May	95	48	143
2021 April	233	126	359
2021 March	160	26	186
2021 February	128	35	163
2021 January	97	21	118
2020 December	70	15	85
2020 November	102	27	129
2020 October	92	21	113
2020 September	95	28	123
2020 August	111	30	141
2020 July	130	31	161
2020 June	100	28	128
2020 May	118	24	142
2020 April	89	12	101
2020 March	87	13	100
2020 February	87	19	106
2020 January	88	20	108
2019 December	95	22	117
2019 November	59	18	77
2019 October	74	14	88
2019 September	73	16	89
2019 August	206	25	231
2019 July	252	16	268
2019 June	241	18	259
2019 May	235	17	252
2019 April	250	20	270
2019 March	304	14	318
2019 February	272	8	280
2019 January	309	27	336
2018 December	70	11	81
2018 November	88	2	90
2018 October	104	14	118
2018 September	28	8	36
2018 August	40	31	71
2018 July	42	19	61
2018 June	50	16	66
2018 May	56	16	72
2018 April	100	35	135
2018 March	45	16	61
2018 February	8	9	17
2018 January	13	13	26
2017 December	19	23	42
2017 November	16	19	35
2017 October	21	14	35
2017 September	14	22	36
2017 August	19	17	36
2017 July	15	14	29
2017 June	16	14	30
2017 May	17	21	38
2017 April	9	3	12
2017 March	6	11	17
2017 February	7	9	16
2017 January	13	10	23
2016 December	12	9	21
2016 November	10	7	17
2016 October	7	15	22
2016 September	5	6	11
2016 August	11	11	22
2016 July	9	10	19
2016 June	0	30	30
2016 May	1	8	9
2016 April	21	18	39
2016 March	37	18	55
2016 February	45	24	69
2016 January	36	18	54
2015 December	93	51	144
2015 November	92	54	146
2015 October	133	83	216
2015 September	190	134	324

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