Although tobacco smoking is a major risk factor for chronic obstructive pulmonary disease (COPD), more than one-fourth of COPD patients are non-smokers. In this cross-sectional study, the differences in COPD phenotypes between non-smokers and smokers in male subjects were investigated and were focused on structural lung changes using a quantitative assessment of computed tomography (CT) images.They divided male participants with COPD, from a Korean cohort near a cement plant, into non-smokers and smokers by a cutoff of a 5 pack-year smoking history. Clinical characteristics, including age, body mass index (BMI), spirometry results, history of biomass smoke exposure, and CT measurements, were compared between the two groups. Emphysema index (EI) and mean wall area percentage (MWA

作者：Wonjun, Ji；Myoung Nam, Lim；So Hyeon, Bak；Seok-Ho, Hong；Seon-Sook, Han；Seung-Joon, Lee；Woo Jin, Kim；Yoonki, Hong

来源：The clinical respiratory journal 2016 年