title: Diabetes mellitus and the risk of gallbladder disease: A systematic review and meta-analysis of prospective studies.
abstract: BACKGROUND
  Diabetes has been hypothesized to increase the risk of gallbladder disease based on the observation that obesity and insulin resistance are associated with gallbladder disease. Although several studies have investigated the association between a diabetes diagnosis and risk of gallbladder disease, the results have not been entirely consistent. For this reason we conducted a systematic review and meta-analysis of the available cohort studies.
  
  
  METHODS
  We searched the PubMed and Embase databases for studies of diabetes and gallbladder disease (defined as gallstones, cholecystectomy, or cholecystitis) up to January 9th 2015. Prospective studies were included if they reported relative risk estimates and 95% confidence intervals of gallbladder disease associated with a diabetes diagnosis. Summary relative risks were estimated by use of a random effects model.
  
  
  RESULTS
  We identified 10 prospective studies that could be included in the meta-analysis which included 223,651 cases among 7,365,198 participants. The summary RR for diabetes patients was 1.56 (95% CI: 1.26-1.93, I(2)=99.4%, pheterogeneity<0.0001). The results persisted when stratified by gender, and in most subgroup analyses and there was no heterogeneity among studies with more than 10 years duration of follow-up. There was no evidence of publication bias.
  
  
  CONCLUSIONS
  Our analysis provides further support for an increased risk of gallbladder disease among diabetes patients.
authors.affiliation: Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway; Department of Epidemiology and Biostatistics, School of Public Health, Imperial College, London, United Kingdom. Electronic address: d.aune@imperial.ac.uk.
authors.forename: Dagfinn
authors.initials: D
authors.lastname: Aune
authors.affiliation: Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Lars J
authors.initials: LJ
authors.lastname: Vatten
mesh_terms: D048909:Diabetes Complications / Q000453:epidemiology; D003920:Diabetes Mellitus / Q000453:epidemiology*; D005705:Gallbladder Diseases / Q000150:complications / Q000453:epidemiology*; D006801:Humans; D007333:Insulin Resistance; D009765:Obesity / Q000150:complications / Q000453:epidemiology; D011446:Prospective Studies; D012307:Risk Factors
keywords: Diabetes mellitus; Gallbladder disease; Gallstones; Meta-analysis; Systematic review