Table 1– Subject characteristics
SubjectsAge yearsMales/femalesSmoking history pack-yearsFEV1/FVC %
Nonsmoker1362±42/11080±2
Smoker without COPD1361±410/350±1283±1
Smoker with COPD1062±410/058±853±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.