Characteristics of the study population
| Sex F/M | 141/415 |
| Age yr | 65±8 |
| Height cm | 168±8 |
| Weight kg | 66±13 |
| Body mass index kg·m−2 | 23.2±4.4 |
| FEV1 % | 36±13 |
| IVC % | 73±18 |
| Pa,O2 kPa | 8.9±1.6 |
| Pa,CO2 kPa | 5.4±0.9 |
Data presented as mean±sd
F: Female
M: male
FEV1: forced expiratory volume in one second
IVC: inspiratory vital capacity
Pa,O2: arterial oxygen tension
Pa,CO2: arterial carbon dioxide tension.