Subject characteristics and pulmonary function data
| Younger | Older | COPD | |
| Subjects | 12 | 15 | 11 |
| Males/females | 7/5 | 7/8 | 4/7 |
| Age years | 30.3±5.5* | 68.3±5.0 | 67.8±8.1 |
| Weight kg | 71.4±15.2 | 75.8±13.3 | 70.6±16.6 |
| Height, m | 1.78±0.05* | 1.70±0.07 | 1.64±0.07* |
| BMI kg·m−2 | 24.1±2.6 | 26.1±3.5 | 26.3±5.6 |
| Smoking history pack-years | 0 | 13.3±12.9 | 44.2±16.9* |
| Pulmonary function | |||
| FEV1 L (% predicted) | 2.98±0.82 (109±11) | 1.52±0.33* (63±15)* | |
| FEV1/FVC (% predicted) | 0.78±0.51 (104±7) | 0.49±0.10* (65±13)* | |
| FRC L (% predicted) | 3.38±0.65 (107±15) | 4.25±1.04* (143±24)* | |
| RV L (% predicted) | 2.27±0.36 (99 ±15) | 3.38±0.83* (156±36)* | |
| TLC L (% predicted) | 6.18±1.19 (102±7) | 6.35±1.33 (116±17)* | |
| IC/TLC (% predicted) | 0.45±0.06 (95±12) | 0.33±0.05* (73±11)* | |
| DLCO mL·min−1·mmHg−1 (% predicted) | 25.2±7.6 (95±17) | 16.3±6.7* (69±28)* |
Data are presented as n or mean±sd. Younger: younger healthy subjects; Older: older healthy subjects; COPD: chronic obstructive pulmonary disease; BMI: body mass index; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; FRC: functional residual capacity; RV: residual volume; TLC: total lung capacity; IC: inspiratory capacity; DLCO: diffusing capacity of the lung for carbon monoxide. *: p≤0.05 versus Older.