General characteristics and lung function measurements
| Smokers | COPD | |
| Age yrs | 58±10 | 65±7 |
| Tobacco consumption pack-yrs# | 41±25 | 42±14 |
| FEV1 % pred | 86±6 | 66±10* |
| FVC % pred | 88±5 | 79±12 |
| RV % pred | 107±11 | 145±18* |
| TLC % pred | 91±4 | 102±10 |
| Pa,O2 mmHg | 94±9 | 85±9 |
| DL,CO % pred | 84±13 | 86±18 |
Data are presented as mean±SD
COPD: chronic obstructive pulmonary disease
FEV1: forced expiratory volume in one second
% pred: % predicted
FVC: forced vital capacity
RV: residual volume
TLC: total lung capacity
Pa,O2: oxygen tension in arterial blood
DL,CO: carbon monoxide diffusing lung capacity corrected for hemoglobin concentration and alveolar volume
*: p<0.05
#: 1 pack-yr is equivalent to 1 yr smoking 20 cigarettes·day−1