Table 1. Characteristics of the participants.
| Controls (n = 25) | COPD(n = 25) | pvalue | |
| Age (yr) | 52±11 | 56±9 | p = NS |
| Gender (M/F) | 14/11 | 14/11 | p = NS |
| Height (m) | 1.71±0.09 | 1.71±0.25 | p = NS |
| Weight (Kg) | 69±15 | 67±15 | p = NS |
| Body mass Index | 23±3 | 23±3 | p = NS |
| FEV1/FVC (% predicted) | 79±5 | 44±14 | p<0.001 |
| FEV1 (% predicted) | 106±11 | 52±22 | p<0.001 |
| RV (%predicted) | 103±17 | 182±56 | p<0.001 |
| TLC (%predicted) | 110±13 | 122±22 | p<0.001 |
| PaO2 (kPa) | 12.3±1 | 10±1.4 | p<0.001 |
| PaCO2 (kPa) | 5.3±0.4 | 5±0.5 | p = NS |
| Dyspnea at rest (Borg scale) | 0 | 3.5±1 | p<0.001 |
Values are mean ± SD. Pulmonary function estimate: FEV1/FVC forced expiratory volume in one sec/forced vital capacity; FEV1: forced expiratory volume in one sec; RV: residual volume; TLC: total lung capacity.