title: Sex differences of COPD phenotypes in nonsmoking patients.
abstract: BACKGROUND
  There is growing evidence about sex-related phenotypes of COPD. However, the sex differences in COPD mainly result from smokers. This study evaluated the sex differences in nonsmoking patients with COPD, focusing on structural changes in the lungs in airway diseases and emphysema.
  
  
  METHODS
  Ninety-seven nonsmoking patients, defined as having <1 pack-year of lifetime cigarette smoking, diagnosed with COPD were selected from a Korean COPD cohort. Emphysema extent and mean wall area percentage (WA%) on computed tomography were compared between the male and female groups.
  
  
  RESULTS
  The 97 patients with COPD included 62 females and 35 males. Emphysema index was significantly lower (3.5±4.2 vs 6.2±5.7, P<0.01) and mean WA% on computed tomography was significantly higher (71.8%±5% vs 69.4%±5%, P<0.01) in females than in males, after adjusting for age, body mass index, history of biomass exposure, and postbronchodilator forced expiratory volume in 1 second (% of predicted).
  
  
  CONCLUSIONS
  WA% was higher and emphysema extent was lower in nonsmoking females with COPD than in nonsmoking males with COPD. These findings suggest that males may be predisposed to an emphysema phenotype and females may be predisposed to an airway phenotype of COPD.
authors.affiliation: Department of Internal Medicine, Environmental Health Center, Kangwon National University Hospital, Chuncheon, South Korea.
authors.forename: Yoonki
authors.initials: Y
authors.lastname: Hong
authors.affiliation: Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Wonjun
authors.initials: W
authors.lastname: Ji
authors.affiliation: Department of Statistics, Kangwon National University, Chuncheon, South Korea.
authors.forename: Soojeong
authors.initials: S
authors.lastname: An
authors.affiliation: Department of Internal Medicine, Environmental Health Center, Kangwon National University Hospital, Chuncheon, South Korea.
authors.forename: Seon-Sook
authors.initials: SS
authors.lastname: Han
authors.affiliation: Department of Internal Medicine, Environmental Health Center, Kangwon National University Hospital, Chuncheon, South Korea.
authors.forename: Seung-Joon
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Environmental Health Center, Kangwon National University Hospital, Chuncheon, South Korea.
authors.forename: Woo Jin
authors.initials: WJ
authors.lastname: Kim
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D056151:Airway Remodeling; D054893:Cone-Beam Computed Tomography; D003430:Cross-Sectional Studies; D005260:Female; D005541:Forced Expiratory Volume; D054624:Health Status Disparities; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging* / Q000503:physiopathology; D056910:Republic of Korea; D012720:Severity of Illness Index; D012737:Sex Factors; D014797:Vital Capacity
keywords: COPD; airway; emphysema; nonsmoker; sex