title: Determinants of exercise capacity in obese and non-obese COPD patients.
abstract: BACKGROUND
  The effects of obesity in combination with chronic obstructive pulmonary disease (COPD) on exercise capacity are receiving increased attention. But, a comprehensive analysis of factors associated with aerobic capacity in obese COPD patients has not been performed.
  
  
  METHODS
  Six-min walking test (6MWT) was performed in 251 COPD patients, and 159 of those also carried out an incremental cardiopulmonary exercise test (CPET) to evaluate exercise capacity. In all patients, anthropometrics, dyspnea and anxiety-depression scores, lung function, daily physical activity, co-morbidities and circulating inflammatory biomarkers were also assessed. Six-min walking distance (6MWD) and peak oxygen uptake (VO2 peak) during CPET were two primary outcome variables.
  
  
  RESULTS
  57% of the patients showed body mass index (BMI) < 30 kg/m2 (COPDN) and the remaining 43% were obese with a BMI ≥ 30 kg/m2 (COPDO). In patients with COPDN, 6MWD showed independent negative associations with age, dyspnea score, sedentarism, depression scores and a positive relationship with arterial oxygenation; whereas in COPDO, 6MWD showed an inverse relationship with BMI. In COPDN, VO2 peak showed a negative association with age and positive relationships with both FEV1 and DLCO. However, in COPDO the dyspnea score was the strongest determinant of VO2 peak.
  
  
  CONCLUSIONS
  Obese and non-obese COPD patients show different determinants of aerobic capacity, including pulmonary and non-pulmonary factors that are also dependent on the type of exercise protocol. These results could be considered in the evaluation of obese patients with COPD.
authors.affiliation: Servei de Pneumologia (ICT), Hospital Clinic, IDIBAPS, Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Universitat de Barcelona, Villaroel 170, 08036 Barcelona, Catalonia, Spain; Muscle and Respiratory System Research Unit and Respiratory Medicine Department, IMIM-Hospital del Mar, Barcelona, Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Health and Experimental Sciences Department (CEXS), Universitat Pompeu Fabra (UPF), Passeig Maritim 25, 08003 Barcelona, Catalonia, Spain. Electronic address: darodriguez@parcdesalutmar.cat.
authors.forename: Diego A
authors.initials: DA
authors.lastname: Rodríguez
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Department of Experimental and Health Sciences, Universitat Pompeu Fabra, CIBER EpidemiologÍa y Salud Pública (CIBERESP), Doctor Aiguader 88, 08003 Barcelona, Catalonia, Spain.
authors.forename: Judith
authors.initials: J
authors.lastname: Garcia-Aymerich
authors.affiliation: Hospital Son Espases, Carretera de Valldemossa 79, 07120 Palma de Mallorca, Spain.
authors.forename: Jose L
authors.initials: JL
authors.lastname: Valera
authors.affiliation: Hospital Son Espases, Carretera de Valldemossa 79, 07120 Palma de Mallorca, Spain.
authors.forename: Jaume
authors.initials: J
authors.lastname: Sauleda
authors.affiliation: Hospital Son Espases, Carretera de Valldemossa 79, 07120 Palma de Mallorca, Spain.
authors.forename: Bernat
authors.initials: B
authors.lastname: Togores
authors.affiliation: Hospital Cruces, Universidad del País Vasco, Plaza de Cruces 12, 48903 San Vicente de Barakaldo, Vizcaya, Spain.
authors.forename: Juan B
authors.initials: JB
authors.lastname: Galdiz
authors.affiliation: Muscle and Respiratory System Research Unit and Respiratory Medicine Department, IMIM-Hospital del Mar, Barcelona, Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Health and Experimental Sciences Department (CEXS), Universitat Pompeu Fabra (UPF), Passeig Maritim 25, 08003 Barcelona, Catalonia, Spain.
authors.forename: Joaquim
authors.initials: J
authors.lastname: Gea
authors.affiliation: Muscle and Respiratory System Research Unit and Respiratory Medicine Department, IMIM-Hospital del Mar, Barcelona, Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Health and Experimental Sciences Department (CEXS), Universitat Pompeu Fabra (UPF), Passeig Maritim 25, 08003 Barcelona, Catalonia, Spain; Respiratory Department, Fundación Cardiovascular de Colombia, Calle 155A No. 23-58, Urbanización El Bosque Floridablanca, Santander Floridablanca, Santander, Colombia.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Orozco-Levi
authors.affiliation: Muscle and Respiratory System Research Unit and Respiratory Medicine Department, IMIM-Hospital del Mar, Barcelona, Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Health and Experimental Sciences Department (CEXS), Universitat Pompeu Fabra (UPF), Passeig Maritim 25, 08003 Barcelona, Catalonia, Spain.
authors.forename: Antoni
authors.initials: A
authors.lastname: Ferrer
authors.affiliation: Servei de Pneumologia (ICT), Hospital Clinic, IDIBAPS, Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Universitat de Barcelona, Villaroel 170, 08036 Barcelona, Catalonia, Spain.
authors.forename: Federico P
authors.initials: FP
authors.lastname: Gomez
authors.affiliation: Servei de Pneumologia (ICT), Hospital Clinic, IDIBAPS, Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Universitat de Barcelona, Villaroel 170, 08036 Barcelona, Catalonia, Spain.
authors.forename: Joan Albert
authors.initials: JA
authors.lastname: Barberà
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), CIBER EpidemiologÍa y Salud Pública (CIBERESP), Doctor Aiguader 88, 08003 Barcelona, Catalonia, Spain.
authors.forename: Ignasi
authors.initials: I
authors.lastname: Serra
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Municipal Institute of Medical Research (IMIM-Hospital del Mar), Department of Experimental and Health Sciences, Universitat Pompeu Fabra, CIBER EpidemiologÍa y Salud Pública (CIBERESP), Doctor Aiguader 88, 08003 Barcelona, Catalonia, Spain.
authors.forename: Josep M
authors.initials: JM
authors.lastname: Antó
authors.affiliation: Servei de Pneumologia (ICT), Hospital Clinic, IDIBAPS, Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Universitat de Barcelona, Villaroel 170, 08036 Barcelona, Catalonia, Spain.
authors.forename: Josep
authors.initials: J
authors.lastname: Roca
mesh_terms: D000368:Aged; D001823:Body Composition / Q000502:physiology; D005080:Exercise Test / Q000379:methods; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D007249:Inflammation / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D009765:Obesity / Q000150:complications / Q000503:physiopathology*; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption / Q000502:physiology; D010313:Partial Pressure; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000503:physiopathology*
chemical_list: D010100:Oxygen
keywords: COPD; Comorbidity; Exercise; Obesity