Patient characteristics
| All | GOLD 0 | COPD (GOLD 1–4) | GOLD 0 versus COPD | |
| Subjects | 36 | 8 | 28 (1 n=6, 2 n=14, 3 n=6, 4 n=2) | |
| Age years | 70.3±5.8 | 70.3±7.1 | 70.3±5.5 | ns |
| mMRC | 0.9±1.0 | 0.4±0.5 | 1.1±1.0 | ns |
| CAT score | 10.1±6.1 | 9.6±4.0 | 10.2±6.7 | ns |
| BMI kg·m−2 | 21.9±3.2 | 21.2±3.7 | 22.1±3.2 | ns |
| Fat mass % | 23.3±5.0 | 24.6±3.4 | 22.9±5.3 | ns |
| FFMI kg·m−2 | 16.7±2.3 | 15.9±2.7 | 16.9±2.2 | ns |
| SMI kg·m−2 | 9.1±1.0 | 8.8±1.2 | 9.2±0.9 | ns |
| Grip strength kg | 33.9±7.0 | 29.6±6.1 | 35.1±6.8 | p<0.05 |
| PEmax % | 72.6±18.7 | 71.8±22.1 | 72.8±18.0 | ns |
| PImax % | 87.6±29.3 | 89.8±15.7 | 87.0±32.3 | ns |
| Vital capacity % | 95.3±16.2 | 98.9±12.0 | 94.2±17.2 | ns |
| FEV1 % pred | 69.4±24.4 | 94.6±10.7 | 62.1±22.3 | p<0.001 |
| FEV1/FVC % | 55.4±17.4 | 78.5±7.8 | 48.8±13.2 | p<0.0001 |
| Residual volume % | 117.1±35.4 | 99.4±17.2 | 122.2±37.7 | ns |
| DLCO/VA % | 74.0±27.4 | 83.1±19.4 | 71.5±29.0 | ns |
| LAA % | 13.9±13.6 | 9.4±8.6 | 15.1±14.6 | ns |
| 6MWD m | 435±95 | 442±23 | 433±107 | ns |
| ΔSpO2 % | 7.3±4.6 | 4.4±2.4 | 8.1±4.7 | p<0.05 |
| ΔHR beats·min−1 | 38.2±15.2 | 31.5±7.2 | 40.1±16.4 | ns |
| Dyspnoea | 2.2±2.2 | 1.1±1.4 | 2.5±2.4 | ns |
| Leg fatigue | 0.7±1.3 | 0.8±1.2 | 0.7±1.3 | ns |
Data are presented as n or mean±sd, unless otherwise stated. GOLD: Global Initiative for Chronic Obstructive Lung Disease; mMRC: modified Medical Research Council dyspnoea scale; CAT: COPD Assessment Test; BMI: body mass index; FFMI: fat-free mass index; SMI: skeletal muscle mass index; PEmax: maximum expiratory pressure; PImax: maximum inspiratory pressure; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; DLCO: diffusing capacity of the lung for carbon monoxide; VA: alveolar volume; LAA: low attenuation area; 6MWD: 6-min walk distance; SpO2: percutaneous oxygen saturation; ΔHR: difference in heart rate; ns: nonsignificant.