title: Current and past smoking significantly increase risk for Barrett's esophagus.
abstract: OBJECTIVE
  Barrett's esophagus (BE) is the precursor to esophageal adenocarcinoma; the incidence of this cancer is rapidly increasing in Western populations. However, few population-based studies of BE have been conducted, so little is known about potentially modifiable causes of this disease.
  
  
  METHODS
  The study included patients with newly diagnosed BE, confirmed by histology and categorized as simple BE (without dysplasia, n = 285) or dysplastic BE (with dysplasia, n = 108). We recruited 2 separate control groups: endoscopy patients with acute inflammatory changes (inflammation controls, n = 313) and population controls sampled from a population register (n = 644). Data were collected through standardized questionnaires and telephone interviews. We fit logistic regression models to calculate odds ratios (ORs) for BE associated with salient exposures by using each set of controls.
  
  
  RESULTS
  Relative to never smokers, risks of simple BE were significantly higher among former smokers (OR, 2.39; 95% confidence interval, 1.59-3.60) and current smokers (OR, 2.41; 95% confidence interval, 1.39-4.17), compared with population controls. Smoking conferred more than a 4-fold increase in risk for dysplastic BE; this increase in risk remained long after individuals quit smoking. We found no conclusive association between BE and passive smoking and no evidence of independent associations between body mass index (BMI) and simple BE or dysplastic BE, after adjusting for reflux and other factors. Analyses with inflammation controls produced qualitatively similar risk estimates for smoking and BMI to those obtained for population controls, but they were markedly attenuated for reflux, as expected.
  
  
  CONCLUSIONS
  Current and past smoking significantly increases risk for BE, but BMI does not, after adjustment for the effect of reflux.
authors.affiliation: Division of Population Studies and Human Genetics, Queensland Institute of Medical Research, Brisbane, Australia. kylie.smith@qimr.edu.au
authors.forename: Kylie J
authors.initials: KJ
authors.lastname: Smith
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: O'Brien
authors.forename: Adèle C
authors.initials: AC
authors.lastname: Green
authors.forename: Penelope M
authors.initials: PM
authors.lastname: Webb
authors.forename: David C
authors.initials: DC
authors.lastname: Whiteman
mesh_terms: D000328:Adult; D000368:Aged; D001471:Barrett Esophagus / Q000453:epidemiology* / Q000473:pathology; D015992:Body Mass Index; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D011795:Surveys and Questionnaires