title: The effect of alcohol, tobacco and caffeine consumption and vegetarian diet on gallstone prevalence.
abstract: OBJECTIVE
  To investigate the effects of alcohol, tobacco and caffeine consumption and of vegetarian diet on gallstone prevalence in an urban population sample.
  
  
  METHODS
  A total of 2417 individuals underwent ultrasound examination and completed a standardized questionnaire as part of the EMIL study. Statistical analysis of the data considered the known risk factors of age, female sex, BMI, positive family history and potential confounders, such as alcohol, caffeine and tobacco consumption and vegetarian diet using multiple logistic regression with variable selection.
  
  
  RESULTS
  The prevalence of gallstones in the population sample was 8% (171 out of 2147). Findings of the study confirmed the classic risk factors of age, female sex, obesity and positive family history. After the variable selection of potential risk factors in a logistic regression that was adjusted for age, female sex, BMI and positive family history, the factors like tobacco [odds ratio (OR) 1.09, 95% confidence interval (CI): 0.76-1.56, P=0.64] and caffeine consumption (OR: 0.77, 95% CI: 0.42-1.42, P=0.40) as well as vegetarian diet (OR: 1.14, 95% CI: 0.39-3.35, P=0.81) had no effect on gallstone prevalence. A protective effect against development of gallstones was shown for alcohol consumption (OR: 0.67, 95% CI: 0.46-0.99, P=0.04).
  
  
  CONCLUSIONS
  The factors like tobacco and caffeine consumption as well as vegetarian diet exerted no measurable effect on the prevalence of gallstones. A protective effect was found for alcohol consumption.
authors.affiliation: Department of Internal Medicine II, University Hospital Ulm, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Walcher
authors.forename: Mark Martin
authors.initials: MM
authors.lastname: Haenle
authors.forename: Richard Andrew
authors.initials: RA
authors.lastname: Mason
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Koenig
authors.forename: Armin
authors.initials: A
authors.lastname: Imhof
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Kratzer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000009:adverse effects / Q000453:epidemiology*; D001628:Beverages; D002110:Caffeine / Q000008:administration & dosage* / Q000009:adverse effects; D014676:Diet, Vegetarian / Q000009:adverse effects; D005260:Female; D042882:Gallstones / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D005858:Germany / Q000453:epidemiology; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D014505:Urban Population; D055815:Young Adult
chemical_list: D002110:Caffeine