Baseline characteristics of study subjects
| COPD | Controls | p-value | |
| Subjects n | 15 | 15 | |
| Age yrs | 60.9±1.4 | 60.7±1.4 | 0.919 |
| Height m | 1.71±0.02 | 1.75±0.03 | 0.254 |
| Weight kg | 78.7±3.1 | 81.1±2.6 | 0.553 |
| BMI kg·m−2 | 27.0±1.1 | 26.5±0.9 | 0.735 |
| FEV1 % pred | 46.4±3.7 | 101.4±2.5 | <0.001 |
| FEV1/VC | 53.5±2.8 | 79.0±1.0 | <0.001 |
| VC % pred | 63.1±4.1 | 95.2±3.0 | <0.001 |
| RV/TLC | 47.3±3.2 | 35.1±2.9 | 0.017 |
| P0.1 kPa | 0.39±0.05 | 0.11±0.03 | <0.001 |
| PI,max kPa | 5.64±0.64 | 8.41±0.95 | 0.026 |
| Arterial pH | 7.38±0.01 | 7.38±0.01 | 0.797 |
| Pa,CO2 mmHg | 42.0±0.91 | 39.1±1.05 | 0.048 |
| Pa,O2 mmHg | 76.5±2.3 | 82.5±2.8 | 0.112 |
| Sa,O2 % | 94.5±0.5 | 95.3±0.5 | 0.284 |
| Systolic blood pressure mmHg | 127.5±8.2 | 135.6±7.6 | 0.476 |
| Diastolic blood pressure mmHg | 62.8±3.5 | 68.7±3.4 | 0.244 |
| fC beats·min−1 | 79.0±3.2 | 69.7±1.7 | 0.016 |
| Respiratory rate breaths·min−1 | 16.2±1.1 | 16.9±0.7 | 0.603 |
| Adrenaline ng·L−1 | 26.6±3.9 | 27.9±4.7 | 0.844 |
| Noradrenaline ng·L−1 | 222.6±16.0 | 218.0±22.9 | 0.869 |
Data are presented as mean±sem, unless otherwise stated. COPD: chronic obstructive pulmonary disease; BMI: body mass index; FEV1: forced expiratory volume in one second; % pred: % predicted; VC: vital capacity; RV: residual volume; TLC: total lung capacity; P0.1: mouth occlusion pressure at 0.1 s; PI,max: maximal inspiratory pressure; Pa,CO2: arterial carbon dioxide tension; Pa,O2: arterial oxygen tension; Sa,O2: arterial oxygen saturation; fC: cardiac frequency. 1 mmHg = 0.133 kPa.