Table 1.
Demographics of the Study Groups
| Parameter | Healthy Nonsmokers | Healthy Smokers | P Value* |
|---|---|---|---|
| Number of subjects | 11 | 7 | |
| Sex, M/F | 6/5 | 5/2 | 0.82 |
| Age, yr | 31.4 ± 11.3† | 42.1 ± 10.4 | 0.06 |
| Race (black/white/other) | 2/4/5 | 5/1/1 | 0.28 |
| Smoking history, pack-year | 0 | 30.2 ± 24.0 | |
| Urine nicotine, ng/ml | Negative | 2,482 ± 2,480 | |
| Urine cotinine, ng/ml | Negative | 2,106 ± 755 | |
| Pulmonary function parameters‡ | |||
| FVC | 100.7 ± 10.7 | 109.7 ± 16.2 | 0.23 |
| FEV1 | 98.5 ± 10.4 | 105.4 ± 18.1 | 0.38 |
| FEV1/FVC | 83.2 ± 7.1 | 77.9 ± 4.2 | 0.06 |
| TLC | 106.3 ± 16.2 | 100.9 ± 11.3 | 0.42 |
| DlCO | 92.5 ± 6.1 | 89.9 ± 9.0 | 0.52 |
Definition of abbreviations: DlCO, diffusing capacity of the lung for carbon monoxide; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; TLC, total lung capacity.
*
Two-tailed t test between samples assuming unequal variance or Chi-square test.
†
Data are presented as mean ± SD.
‡
Pulmonary function testing parameters are given as % predicted value with the exception of FEV1/FVC, which is reported as % observed. FVC, FEV1, and FEV1/FVC are prebronchodilator values.