title: Dose-related effect of urinary cotinine levels on pulmonary function among Korean women.
abstract: METHODS
  Country-wide general population in South Korea.
  
  
  BACKGROUND
  The dose-response relationship between smoking and pulmonary function in women may have been significantly over-estimated by studies that employed a self-reporting questionnaire.
  
  
  OBJECTIVE
  To evaluate whether this relationship was still observed among Korean women when smoking levels were determined by urinary cotinine measurements.
  
  
  METHODS
  A total of 4584 Korean women from the spirometry data set of the Korean National Health and Nutrition Examination Surveys IV and V (2008-2010) were included. Analysis of covariance was performed to estimate the dose-related effect of urinary cotinine levels on pulmonary function after adjusting for covariates in this country-wide cross-sectional study.
  
  
  RESULTS
  Compared to urinary cotinine levels (cut-off 50 ng/ml), the false-positive rate of self-reported smoking was 53.2%. After the smokers were divided into deciles, the regression coefficients for percentage forced expiratory volume in 1 second (FEV₁%) and percentage forced expiratory volume/forced volume capacity (FEV₁/FVC) ratio (FEV1/FVC%) were -0.2903 and -0.2680 (%/decile), respectively (both P < 0.001).
  
  
  CONCLUSIONS
  It is necessary to use objective methods when determining the smoking status of Korean women. Even after reducing information bias, smoking affected pulmonary function in a dose-dependent manner.
authors.affiliation: Department of Occupational & Environmental Medicine, Korea Medical Institute, Seoul, Republic of Korea.
authors.forename: K Y
authors.initials: KY
authors.lastname: Kim
authors.affiliation: Department of Occupational & Environmental Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: J-P
authors.initials: JP
authors.lastname: Myong
authors.affiliation: Department of Occupational & Environmental Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: H-R
authors.initials: HR
authors.lastname: Kim
authors.affiliation: Department of Occupational & Environmental Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: H E
authors.initials: HE
authors.lastname: Lee
authors.affiliation: Department of Occupational & Environmental Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: T-W
authors.initials: TW
authors.lastname: Jang
authors.affiliation: Department of Occupational & Environmental Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: J-W
authors.initials: JW
authors.lastname: Koo
authors.affiliation: Department of Occupational & Environmental Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: C Y
authors.initials: CY
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000652:urine; D003367:Cotinine / Q000652:urine*; D003430:Cross-Sectional Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D005541:Forced Expiratory Volume; D006306:Health Surveys; D006801:Humans; D008168:Lung / Q000187:drug effects* / Q000503:physiopathology; D008875:Middle Aged; D009538:Nicotine / Q000009:adverse effects* / Q000652:urine*; D018722:Nicotinic Agonists / Q000009:adverse effects* / Q000652:urine*; D056910:Republic of Korea; D012129:Respiratory Function Tests; D012907:Smoking / Q000009:adverse effects*; D011795:Surveys and Questionnaires; D014797:Vital Capacity
chemical_list: D015415:Biomarkers; D018722:Nicotinic Agonists; D009538:Nicotine; D003367:Cotinine