Table 1—

Clinical and functional characteristics of the population studied

Never-smokersSmokers with normal lung functionSmokers with COPD
Subjects n262426
Age yrs57±258±261±1
Sex male/female26/024/026/0
Smoking history pack-yrs0±039±4#49±3#
FEV1 % reference106±394±2#48±4#,¶
FEV1/FVC %80±182±352±2#,¶
  • Data are presented as mean±sem, unless otherwise stated. COPD: chronic obstructive pulmonary disease; FEV1: forced expiratory volume in one second; FVC: forced vital capacity. #: p<0.01 versus never-smokers; : p<0.01 versus smokers with normal lung function.