Table 1. General characteristics of the study groups.
| COPD(n = 43) | Non-COPD, current smokers(n = 11) | Non-COPD, former smokers(n = 13) | Non-COPD, never smokers(n = 8) | P value* | |
|---|---|---|---|---|---|
| Males, n (%) | 40 (93.0) | 8 (72.7) | 13 (100) | 6 (75.0) | 0.070 |
| Age, years | 65.8 (7.7) | 63.9 (11.3) | 63.0 (12.4) | 69.6 (7.0) | 0.594 |
| Tobacco history, pack-year) | 61.7 (37.4) | 55.9 (33.65) | 49.9 (35.2) | 0 (0) | < 0.001 |
| FEV1, % | 69.8 (16.7) | 85.8 (18.1) | 93.0 (12.1) | 85.8 (18.1) | < 0.001 |
| FEV1/FVC, % | 58.5 (9.8) | 75.7 (4.3) | 74.3 (3.2) | 73.1 (8.0) | < 0.001 |
| LABA, n (%) | 13 (31.0) | 1 (9.1) | 2 (15.4) | 0 (0) | 0.128 |
| Inhaled steroids, n (%) | 8 (19.0) | 1 (9.1) | 2 (15.4) | 0 (0) | 0.518 |
| LAMA, n (%) | 15 (35.7) | 1 (9.1) | 2 (15.4) | 0 (0) | 0.058 |
| Oral steroids (n) | 0 (0) | 0 (0) | 3 (23.1) | 0 (0) | 0.002 |
Data expressed as means (standard deviations) or absolute (relative) frequencies, as appropriate. FEV1: forced expiratory volume in one second; FVC: forced vital capacity; LABA: long-acting β2-agonists; LAMA: long-acting muscarinic antagonists.
*P values were calculated with the Kruskal–Wallis test for continuous variables and the χ2 test for categorical variables.