title: Bisphenol-A and Sleep Adequacy among Adults in the National Health and Nutrition Examination Surveys.
abstract: OBJECTIVE
  To evaluate bisphenol-A (BPA) level and its relationship to sleep adequacy in a nationally representative sample of U.S. adults.
  
  
  METHODS
  A population-based cross-sectional study was conducted using 2005-2010 National Health and Nutrition Examination Survey whereby data were collected using in-person interviews, physical examination and laboratory testing. BPA level was measured in urine samples and analyzed as loge-transformed variable and in quartiles (< 0.9 ng/mL; 0.9 to < 1.9 ng/mL; 1.9 to < 3.7 ng/mL; 3.7+ ng/mL). Sleep adequacy was operationalized with three questions: "How much sleep do you usually get at night on weekdays or workdays?", "Have you ever told a doctor or other health professionals that you have trouble sleeping?" and "Have you ever been told by a doctor or other health professional that you have a sleep disorder?" Sleep duration was further categorized as (< 6 h, ≥ 6 h); (< 7 h, 7-8 h, > 8 h); (< 5 h, 5-6 h, 7-8 h, ≥ 9 h). Linear, binary, and ordinal logistic regression models were constructed.
  
  
  RESULTS
  Loge-transformed BPA level was inversely related to sleep duration defined, in hours, as a continuous variable, a dichotomous variable (≥ 6, < 6), or an ordinal variable (≥ 9, 7-8, 5-6, < 5), after adjustment for confounders. Help-seeking behavior for sleep problems and diagnosis with sleep disorders were not significantly associated with loge-transformed BPA level in fully adjusted models.
  
  
  CONCLUSIONS
  Loge-transformed BPA level may be associated with fewer hours of sleep among U.S. adults, with implications for prevention. Further research involving diverse populations are needed to confirm these study findings.
authors.affiliation: Graduate Program in Public Health, Eastern Virginia Medical School, Norfolk, VA.
authors.forename: Hind A
authors.initials: HA
authors.lastname: Beydoun
authors.affiliation: Laboratory of Epidemiology and Population Sciences, National Institute on Aging Intramural Research Program, Baltimore, MD.
authors.forename: May A
authors.initials: MA
authors.lastname: Beydoun
authors.affiliation: Department of Community & Environmental Health, Old Dominion University, Norfolk, VA.
authors.forename: Hueiwang Anna
authors.initials: HA
authors.lastname: Jeng
authors.affiliation: Laboratory of Epidemiology and Population Sciences, National Institute on Aging Intramural Research Program, Baltimore, MD.
authors.forename: Alan B
authors.initials: AB
authors.lastname: Zonderman
authors.affiliation: Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Shaker M
authors.initials: SM
authors.lastname: Eid
mesh_terms: D000328:Adult; D000368:Aged; D001559:Benzhydryl Compounds / Q000009:adverse effects / Q000652:urine*; D003430:Cross-Sectional Studies; D005260:Female; D006306:Health Surveys; D000066505:Help-Seeking Behavior; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D010636:Phenols / Q000009:adverse effects / Q000652:urine*; D012890:Sleep / Q000502:physiology*; D012893:Sleep Wake Disorders / Q000139:chemically induced / Q000175:diagnosis / Q000517:prevention & control; D013997:Time Factors; D014481:United States; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D010636:Phenols; C006780:bisphenol A; D000098826:Bisphenol A Compounds
keywords: bisphenol-A; endocrine disruptor; sleep disorder; sleep duration; survey