Physiological characteristics of study subjects
| COPD patients | Normal subjects | |
| Subjects n | 14 | 8 |
| Age yrs | 74.6±5.7 | 60.4±13.5 |
| FEV1 L | 1.20±0.36 | 2.66±1.27 |
| FEV1 % pred | 51.1±15.8 | 89.6±17.7 |
| FVC L | 2.70±0.75 | 3.72±1.66 |
| FEV1/FVC | 47.4±13.4 | 78.4±7.5 |
| Pa,O2 kPa | 8.80±1.82 | 9.96±0.72 |
| Pa,CO2 kPa | 5.20±0.57 | 5.32±0.66 |
| Pack-yrs of smoking | 51.5±24.0 | 49.0±44.0 |
| MRC dyspnoea score | 3.20±1.33 | 1.00±0.00 |
| Current smokers | 8 | 6 |
Data are presented as mean±sd unless otherwise stated
COPD: chronic obstructive pulmonary disease
FEV1: forced expiratory volume in one second
% pred: % predicted
FVC: forced vital capacity
Pa,O2: arterial oxygen tension
Pa,CO2: arterial carbon dioxide tension
MRC: Medical Research Council