Table 1—

Basic characteristic of study groups

CharacteristicsCOPDControls
Total309305
Male243 (79%)222 (73%)
Female61 (21%)84 (27%)
Age (mean±sem) yrs61.5±12.756.1±8.6
FEV1 % pred39.8±6.2ND
Smokers168 (55%)152 (50%)
Nonsmokers138 (45%)153 (50%)
Smoking index pack-yrs35.9±5.327.6±3.7
  • COPD: chronic obstructive pulmonary disease; FEV1: forced expiratory volume in one second; ND: not determined.