title: Bisphenol A exposure and asthma development in school-age children: a longitudinal study.
abstract: BACKGROUND
  Although the effect of bisphenol A on various health outcomes has been extensively examined, few studies have investigated its effect on asthma.
  
  
  OBJECTIVE
  We hypothesized that exposure to bisphenol A in school-age children was associated with wheezing and asthma.
  
  
  METHODS
  Participants included 127 children aged 7-8 years without a previous asthma diagnosis in an elementary school in Seoul, Korea. Three surveys were conducted, each 2 years apart. Bisphenol A concentration was measured at the baseline survey, and PC20, which is defined as the methacholine concentration that induces a decrease in FEV1 of 20% from baseline, was measured at every survey. Associations between bisphenol A concentration at 7-8 years of age and wheezing, asthma, and PC20 at ages up to 11-12 years were examined using generalized estimating equations, a marginal Cox regression model, and a linear mixed model.
  
  
  RESULTS
  The log-transformed creatinine-adjusted urinary bisphenol A concentration at 7-8 years was positively associated with wheezing (odds ratio, 2.48; 95% confidence interval, 1.15-5.31; P = .02) and asthma (hazard ratio, 2.13; 95% confidence interval, 1.51-3.00; P<.001) at ages up to 11-12 years. Bisphenol A was also negatively associated with PC20 (ß = -2.33; P = .02). When stratified by sex, the association between bisphenol A and asthma remained significant only in girls (hazard ratio, 2.45; 95% confidence interval, 2.18-2.76; P<.001).
  
  
  CONCLUSIONS
  Increased urinary bisphenol A concentrations at 7-8 years old were positively associated with wheezing and asthma and negatively associated with PC20 at ages up to 11-12 years.
authors.affiliation: Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kyoung-Nam
authors.initials: KN
authors.lastname: Kim
authors.affiliation: Institute of Environmental Medicine, Medical Research Center, Seoul, Korea.
authors.forename: Jin Hee
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Preventive Medicine and Public Health, Dankook University College of Medicine, Cheonan, Korea.
authors.forename: Ho-Jang
authors.initials: HJ
authors.lastname: Kwon
authors.affiliation: Department of Pediatrics, Childhood Asthma Atopy Center, Research Center for Standardization of Allergic Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Soo-Jong
authors.initials: SJ
authors.lastname: Hong
authors.affiliation: Department of Pediatrics, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
authors.forename: Byoung-Ju
authors.initials: BJ
authors.lastname: Kim
authors.affiliation: Department of Pediatrics, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea.
authors.forename: So-Yeon
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Korea; Institute of Environmental Medicine, Medical Research Center, Seoul, Korea.
authors.forename: Yun-Chul
authors.initials: YC
authors.lastname: Hong
authors.affiliation: Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Sanghyuk
authors.initials: S
authors.lastname: Bae
mesh_terms: D001249:Asthma / Q000139:chemically induced* / Q000652:urine*; D001559:Benzhydryl Compounds / Q000652:urine*; D002648:Child; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D010636:Phenols / Q000652:urine*; D012135:Respiratory Sounds; D012574:Schools; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D010636:Phenols; C006780:bisphenol A; D000098826:Bisphenol A Compounds