Table 1. Subject Demographics.
| COPD | Smokers | Non-smokers | |
| Subjects | 54 | 33 | 19 |
| Sex (F/M) | 21/33 | 18/15 | 13/6 |
| Age (yr) | 66.3 (8.4) | 64.8 (11.7) | 56.9 (12) |
| FEV1 (L) | 1.65 (0.5) | 2.3 (0.7) | 2.4 (0.4) |
| FEV1 % predicted | 65.4 (13.3) | 91.3 (14.9) | 109 (32.05) |
| FVC (L) | 2.96 (0.8) | 3.1 (0.9) | 3 (0.5) |
| FEV1:FVC ratio | 57.9 (9.7) | 79.2 (12.1) | 83.8 (17.1) |
| Smoking history | 53 (22.4) | 37.1 (17.5) | 0 |
| Current/Ex-smoker | 38/16 | 21/12 | na |
| ICS | 16 | 0 | 0 |
Data presented as mean (SD). Forced expiratory volume in 1 second (FEV1), Forced vital capacity (FVC), smoking history is pack years, inhaled corticosteroid (ICS), not applicable (na).