Characteristics of subjects
| Non-smokers(n = 10) | Healthy smokers(n = 12) | Stable COPD(n = 7) | Severe exacerbations of COPD(n = 7) | Very severe exacerbations of COPD(n = 7) | |
|---|---|---|---|---|---|
| Values are shown as mean (SE). | |||||
| FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; Pao2, Paco2, arterial oxygen and carbon dioxide tensions; NA, not applicable; ND, not done. | |||||
| *p<0.05, **p<0.01, ***p<0.001 compared with non-smokers. | |||||
| †p<0.05, ††p<0.01, †††p<0.001 compared with smokers. | |||||
| Age (years) | 53.5 (2.5) | 50.3 (2.1) | 70.3 (5.4)**††† | 57.8 (3.5) | 69.9 (1.6)**††† |
| M/F | 4/6 | 6/6 | 4/3 | 7/0 | 7/0 |
| FEV1 when stable (l) | 3.4 (0.4) | 3.1 (0.2) | 2.47 (0.4)** | 0.89 (0.2)***††† | 0.9 (0.2)***††† |
| FEV1 % predicted when stable | 116.3 (7.7) | 98.5 (3.9) * | 63.7 (7.5)***† | 28.6 (0.14)***†† | 31.4 (6.9)***††† |
| FEV1/FVC ratio (%) | 75.3 (2.6) | 74.4 (1.8) | 58.8 (2.9) | 42.8 (6.5)**† | 46.0 (7.2)**† |
| Smoking (pack years) | NA | 41 (6) | 38 (12) | 52 (5) | 58 (6)† |
| Pao2/Paco2 (kPa) | ND | ND | ND | 8.9 (0.4)/6.0 (0.3) | 6.7 (1.4)/9.1 (1.1) |
| Oral corticosteroids (Y/N) | –/– | –/– | –/7 | –/8 | 3/5 |
| Inhaled corticosteroids (Y/N) | –/7 | 2/5 | 7/1 | ||