Baseline demographic and clinical characteristics
| Subjects n | 236 |
| Disease status at recruitment | |
| Stable | 221 (94) |
| Exacerbated | 15 (6) |
| Age years | 67.4±8.4 |
| Male | 160 (68) |
| Primary ethnicity: white | 231 (98) |
| Living alone | 117 (50) |
| Low socioeconomic status (NS-SEC IV–V) | 39 (16) |
| Working status: employed | 28 (12) |
| Current smoker | 43 (18) |
| Smoking pack-years | 57.2±40.4 |
| BMI kg·m−2 | 27.0±5.5 |
| FFMI kg·m−2# | 18.1±3.0 |
| FEV1 % pred | 57.0±20.5 |
| FVC % pred | 95.6±19.6 |
| FEV1/FVC % | 46.9±13.2 |
| IC/TLC %# | 34.3±9.9 |
| RV/TLC %# | 50.9±11.4 |
| TLCO % pred# | 59.8±22.7 |
| ATS/ERS stages# | |
| I: mild (FEV1 ≥80%) | 34 (15) |
| II: moderate (FEV1 <80% and ≥50%) | 108 (46) |
| III: severe (FEV1 <50% and ≥30%) | 71 (30) |
| IV: very severe (FEV1 <30%) | 22 (9) |
| 6MWD m# | 427.7±129.3 |
| Quadriceps strength kg# | 31.8±11.8 |
| Any admissions for COPD exacerbation ever | 95 (40) |
| Comorbidities | |
| Coronary heart disease | 28 (12) |
| Any cardiovascular disease or disorder¶ | 127 (54) |
| Diabetes | 21 (9) |
| Musculoskeletal disorders | 27 (11) |
| Dyspnoea (mMRC 0–4) | 1.7 (1.1) |
| CRQ dyspnoea# | 4.8 (1.5) |
| CRQ fatigue# | 4.3 (1.3) |
| CRQ emotional# | 4.9 (1.3) |
| CRQ mastery# | 5.3 (1.3) |
| CCQ total# | 1.9 (1.1) |
| CAT# | 15.1 (8.2) |
| HADS anxiety# | 5.6 (4.2) |
| HADS depression# | 5.0 (3.4) |
Data are presented as n, n (%) or mean±sd. NS-SEC: National Statistics Socio-economic Classification; BMI: body mass index; FFMI: fat-free mass index; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; IC: inspiratory capacity; TLC: total lung capacity; RV: residual volume: TLCO: transfer factor of the lung for carbon monoxide; ATS: American Thoracic Society; ERS: European Respiratory Society; 6MWD: 6-min walking distance; COPD: chronic obstructive pulmonary disease; mMRC: modified Medical Research Council dyspnoea scale; CRQ: chronic respiratory questionnaire; CCQ: clinical COPD questionnaire; CAT: COPD assessment test; HADS: hospital anxiety and depression scale. #: some values are missing for certain variables (FFMI n=9, IC/TLC n=15, RV/TLC n=14, TLCO n=8, 6MWD n=3, quadriceps strength n=3, CRQ dyspnoea n=88, CRQ fatigue n=3, CRQ emotional n=3, CRQ mastery n=3, CCQ n=1, CAT n=2, HADS anxiety n=1, HADS depression n=1); ¶: including coronary heart disease.