Subject characteristics
| COPD | Control | p-value | |
| Subjects n | 90 | 93 | |
| Males | 49 (54.4) | 51 (54.8) | 0.96 |
| Age years | 66.2±8.7 | 63.7±8.7 | 0.051 |
| Smoking status | |||
| Current | 17 (18.9) | 7 (7.5) | <0.001 |
| Former | 68 (75.6) | 47 (50.5) | |
| Never | 5 (5.6) | 39 (41.9) | |
| Pack-years# | 28.6±20.9 | 6.6±10.8 | <0.001 |
| BMI kg·m2 | 27.0±5.4 | 27.3±4.7 | 0.7 |
| Allergic rhinitis | 5 (5.6) | 14 (15.1) | 0.035 |
| Nasal corticosteroids | 4 (4.4) | 4 (4.3) | 1.0 |
| Pulmonary function¶ | |||
| FEV1 L | 1.6±0.7 | 3.0±0.9 | <0.001 |
| FEV1 % pred | 53.1±18.7 | 94.6±12.2 | <0.001 |
| FVC L | 3.0±1.0 | 3.7±1.0 | <0.001 |
| FVC % pred | 75.8±18.0 | 93.8±13.0 | <0.001 |
| FEV1/FVC | 0.53±0.12 | 0.78±0.05 | <0.001 |
Data presented as n (%) or mean±sd, unless otherwise stated. The p-values refer to data comparison between COPD and controls. COPD: chronic obstructive pulmonary disease; BMI: body mass index; FEV1: forced expiratory volume in 1 s; % pred: % predicted; FVC: forced vital capacity. #: Missing data in four controls and three COPD; ¶: pre-bronchodilator values in two controls and one COPD. Otherwise, pulmonary function parameters are based on post-bronchodilator measurements.