Table 1. Demographics and clinical characteristics of all participants.
| Variables | HC | HS | COPD |
|---|---|---|---|
| Subjects (No.) | 27 | 24 | 29 |
| Age (year) | 56.5 ± 1.6 | 59.1 ± 0.9 | 58.9 ± 1.3 |
| Gender (Male/female) | 24/3 | 22/2 | 25/4 |
| Tobacco (pack-year) | — | 38 (10–68) | 41 (12–80) |
| FEV1 (% predicted) | 94.4 ± 0.6 | 94.3 ± 0.6 | 51.4 ± 1.7*# |
| FEV1/ FVC (%) | 84.29 ± 1.40 | 80.88 ± 1.25 | 43.37 ± 2.04*# |
| WBC (× 109/L) | 6.66 ± 0.26 | 5.87 ± 0.23 | 6.03 ± 0.27 |
The data are represented as the mean ± SEM or median (range). FEV1: forced expiratory volume in one second; FVC: forced vital capacity; WBC: white blood cell. *P < 0.01 vs. the HC group; #P < 0.01 vs. the HS group.