Participant characteristics
| Variable | COPD, n=50 |
| Age, years | 66 (59, 70) |
| Gender, female/male, n | 23/27 |
| BMI, kg/m2 | 23.9 (21.3, 27.0) |
| Waist–hip ratio | |
| Females | 0.89 (0.83, 0.94) |
| Males | 1.0 (0.94, 1.04) |
| Pulmonary function | |
| FEV1, L | 0.78 (0.59, 1.0) |
| FEV1, % predicted | 28.8 (24.8, 35.1) |
| FVC, L | 1.69 (1.19, 2.28) |
| FVC, % predicted | 50.1 (41.6, 63.7) |
| FEV1/FVC, % | 45.8 (40.8, 53.7) |
| TLC, L | 7.7 (7.0, 9.1) |
| TLC, % predicted | 137.0 (121.8, 154.8) |
| FRCpleth, L | 6.8 (5.9, 7.6) |
| FRCpleth, % predicted | 213.6 (182.0, 251.8) |
| RV, L | 5.9 (5.0, 7.0) |
| RV, % predicted | 269.9 (218.1, 335.6) |
| RV/TLC, % | 77.1 (68.6, 82.7) |
| RV/TLC, % predicted | 188.5 (172.1, 206.9) |
| Raw, kPa s L-1 | 0.87 (0.63, 1.10) |
| Raw, % predicted | 289.6 (209.6, 367.3) |
| sRaw, kPa s | 6.0 (4.4, 8.9) |
| sRaw, % predicted | 575.8 (397.4, 844.0) |
| GOLD grade | |
| III, n | 23 (46) |
| IV, n | 27 (54) |
| Blood gases, room air—rest | |
| pH | 7.41 (7.39, 7.42) |
| PO2, mm Hg | 54.7 (51.0, 57.7) |
| PCO2, mm Hg | 44.2 (38.2, 47.8) |
| Exercise capacity | |
| 6-minute walk distance, m | 303.5 (245.0, 371.5) |
| 6-minute walk distance, % predicted | 48.4 (38.5, 59.5) |
| Incremental shuttle walk test, m | 205.0 (130.0, 325.0) |
| Long-term oxygen therapy | |
| Period of application, months | 47 (18, 79) |
| O2-flow rates, L | |
| Rest | 1.75 (1.0, 2.9) |
| Night | 2.0 (1.0, 2.9) |
Data presented as median (interquartile range (IQR)) or number.
%, per cent; BMI, body mass index; FEV1, forced expiratory volume in 1 s; FRC, functional residual capacity; FVC, forced vital capacity; kg, kilograms; kg/m2, kilograms per metre squared; L, litre; m, metres; mm Hg, millimetres of mercury; n, number; PCO2, partial pressure of carbon dioxide; pH, potential of hydrogen; PO2, partial pressure of oxygen; Raw, airway resistance; RV, residual volume; sRaw, specific airway resistance; TLC, total lung capacity.