Table 1. Characteristics of subjects in the present study.
| Non-smokers | Smokers | Smokers with COPD | |
|---|---|---|---|
| Number | 11 | 17 | 21 |
| Age (years) | 63.8 ± 5.2 | 65.2 ± 6.3 | 66.8 ± 7.1 |
| Male | 11(100%) | 17(100%) | 21(100%) |
| Smoking history (pack-years) | 0 | 40.3 ± 4.7** | 50.5 ± 5.2**# |
| BMI (kg/m2) | 25.8 ± 3.2 | 29.1 ± 5.3 | 27.2 ± 6.3 |
| FEV1 (L) | 3.25 ± 0.12 | 2.98 ± 0.18 | 2.11 ± 0.15*# |
| FVC (L) | 4.06 ± 0.23 | 3.61 ± 0.25 | 3.52 ± 0.18 |
| FEV1/FVC% | 80.05 ± 1.6 | 82.55 ± 1.8 | 64.92 ± 2.1**## |
| FEV1(% predicted) | 105.4 ± 5.3 | 98.6 ± 4.6 | 68.3 ± 3.9**## |
| Occupational dust exposure, n | |||
| Yes | 2 | 1 | 2 |
| No | 9 | 16 | 19 |
| Occupational hazard gas exposure, n | |||
| Yes | 1 | 2 | 2 |
| No | 10 | 15 | 19 |
Abbreviations: COPD: Chronic Obstructive Pulmonary Disease; BMI: body mass index; FVC: forced vital capacity; FEV1 : forced expiratory volume in one second. *P <0.05, ** P <0.01, different from non-smoker. # P <0.05, ## P <0.01 different from smokers.