Characteristics of the study population
| Male | Female | |
| Subjects | 596 | 727 |
| Age years | 48.8±13.2 | 48.2±13.0 |
| Height cm | 176.5±6.6 | 163.0±6.1 |
| BMI kg·m−2 | 26.4±3.9 | 25.9±4.9 |
| FEV1 L | 3.9±0.9 | 2.9±0.6 |
| FVC L | 4.9±0.9 | 3.5±0.6 |
| FEV1/FVC | 0.796±0.082 | 0.822±0.063 |
| FEV1 z-score GLI2012 [10] | 0.04±1.07 | 0.11±0.94 |
| FVC z-score GLI2012 [10] | −0.02±0.90 | −0.03±0.84 |
| FEV1/FVC z-score GLI2012 [10] | 0.09±1.07 | 0.19±0.86 |
| Smoking status | ||
| Nonsmoker | 31.4 | 52.8 |
| Ex-smoker | 36.4 | 22.3 |
| Current smoker | 32.2 | 24.9 |
| Physician-diagnosed asthma | 6.4 | 7.0 |
| Physician-diagnosed COPD | 2.9 | 2.8 |
Data are presented as n, mean±sd or %. BMI: body mass index; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; GLI2012: Global Lung Function Initiative reference values; COPD: chronic obstructive pulmonary disease.