Subjects | Age years | Males/females | Smoking history pack-years | FEV1/FVC % | |
Nonsmoker | 13 | 62±4 | 2/11 | 0 | 80±2 |
Smoker without COPD | 13 | 61±4 | 10/3 | 50±12 | 83±1 |
Smoker with COPD | 10 | 62±4 | 10/0 | 58±8 | 53±3*,** |
Data are presented as n or mean±sem, unless otherwise stated. FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; COPD: chronic obstructive pulmonary disease. *: p<0.05 versus nonsmoker; **: p<0.05 versus smoker without COPD.