title: Body mass index, alcohol, tobacco and symptomatic gallstone disease: a Swedish twin study.
abstract: OBJECTIVE
  Both genetic and environmental factors are involved in the pathogenesis of gallstone disease (GD). We aimed to examine the association between symptomatic GD and overweight (body mass index, BMI, 25-30 kg m(-2)), obesity (BMI > 30 kg m(-2)), alcohol, smoking and smoke-free tobacco by analysing a large twin population.
  
  
  METHODS
  The Swedish Twin Registry (STR) was linked to the Swedish Hospital Discharge and Causes of Death Registries for GD and GD-surgery related diagnoses. Weight, height, use of alcohol, smoking and smoke-free tobacco were provided by STR and analysed for possible associations by conditional logistic regression.
  
  
  RESULTS
  Overweight and obesity were associated with a significantly higher risk for symptomatic GD in the whole study population (OR 1.86 and OR 3.38; CI: 1.52-2.28 and 2.28-5.02 respectively). High alcohol consumption was associated with a lower risk for GD in the whole population (OR 0.62; CI: 0.51-0.74) with no difference between discordant monozygotic and dizygotic twins (OR 1.08 and OR 0.96; CI: 0.82-1.42 and 0.79-1.16). Smoking or smoke-free tobacco was not correlated with GD.
  
  
  CONCLUSIONS
  Consistent with epidemiological studies, we found positive associations between BMI and the development of symptomatic GD. High alcohol consumption was associated with a decreased risk against GD. Tobacco use has no impact on GD.
authors: Department of Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden. despina.katsika@ki.se
authors: D
authors: D
authors: Katsika
authors: C
authors: C
authors: Tuvblad
authors: C
authors: C
authors: Einarsson
authors: P
authors: P
authors: Lichtenstein
authors: H-U
authors: HU
authors: Marschall
mesh_terms: D000428:Alcohol Drinking / Q000453:epidemiology*; D015992:Body Mass Index; D015331:Cohort Studies; D004200:Diseases in Twins / Q000453:epidemiology*; D005260:Female; D042882:Gallstones / Q000453:epidemiology*; D006801:Humans; D008297:Male; D009765:Obesity / Q000453:epidemiology*; D050177:Overweight / Q000453:epidemiology*; D015995:Prevalence; D018570:Risk Assessment / Q000379:methods; D012907:Smoking / Q000453:epidemiology*; D013548:Sweden / Q000453:epidemiology; D014030:Tobacco, Smokeless / Q000009:adverse effects; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic