Patient demographics
| NC | NLFS | COPD-CS | COPD-ES | |
| Subjects | 10 | 11 | 9 | 10 |
| Age years | 50 (19–73) | 69 (52–79)** | 65 (59–78)** | 68 (56–85)** |
| Smoking history pack-years | NS | 27 (0.3–40) | 30 (2–48) | 30 (2–58) |
| FEV1/FVC %# | N/A | 76 (70–90) | 66 (59.9–70) | 64 (55–69) |
| FEF25–75%# | N/A | 79 (47–116) | 37 (28–47) | 41 (20–55) |
Data are presented as n or median (range). NC: normal control; NLFS: normal lung function smoker; COPD-CS: COPD current smoker; COPD-ES: COPD ex-smoker; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; FEF25–75%: forced expiratory flow at 25–75% of FVC; NS: nonsmokers; N/A: not available. #: post-bronchodilator values after 400 µg salbutamol. **: p<0.01 over NC (ordinary one-way ANOVA followed by Dunnett's multiple comparison test).