Table 1.
Subject characteristics
| Group | NS | FS-NAO | CS-NAO | FS-COPD | CS-COPD | p value |
|---|---|---|---|---|---|---|
| Subjects, n | 21 | 29 | 30 | 37 | 22 | |
| Sex ratio, M/F | 8/13 | 13/16 | 16/14 | 24/13 | 12/10 | 0.32 |
| Age, years (SD) | 52 (8) | 63 (8) | 51 (6) | 65 (7) | 60 (7) | <0.0001 |
| Smoking, pack-years (SD) | 0 (0) | 39 (16) | 35 (12) | 51 (24) | 53 (20) | 0.0007 * |
| FEV1, % pred. (SD) | 100 (0) | 102 (12) | 97 (13) | 79 (19) | 78 (17) | <0.0001 |
| FEV1/FVC (SD) | 0.82 (0.06) | 0.76 (0.06) | 0.76 (0.05) | 0.58 (0.09) | 0.58 (0.10) | <0.0001 |
| ICS 3 use (yes/no) | 1/20 | 1/28 | 3/26 ** | 15/22 | 6/16 | 0.0002 |
1
Data are presented as mean (SD) except for sex ratios and ICS use; M, male; F, female;
2
former smoker defined as having quit for more than six months;
3
ICS, inhaled corticosteroids. NS, never-smokers; FS-NAO, former smokers, no airflow obstruction; CS-NAO, current smokers, no airflow obstruction; FS-COPD, former smokers with COPD; CS-COPD, current smokers with COPD. One-way ANOVA with Holm-Sidak post-hoc testing was used to determine significant differences between groups.
*
NS group omitted, no single group statistically different by post-hoc testing.
**
data missing from one subject.