title: Association of Statin Therapy and Risks of Cholelithiasis, Biliary Tract Diseases, and Gallbladder Procedures: Retrospective Cohort Analysis of a US Population.
abstract: BACKGROUND
  Gallstone disease is a leading cause of morbidity in Western countries and carries a high economic burden. Statin medications decrease hepatic cholesterol biosynthesis and may, therefore, lower the risk of cholesterol cholelithiasis by reducing the cholesterol concentration in the bile. Population-based evidence, however, is sparse.
  
  
  OBJECTIVE
  To assess the risk of gallbladder diseases among statin users compared with nonusers in an American patient cohort.
  
  
  METHODS
  We performed a retrospective cohort study of patients enrolled in the San Antonio Tricare health system using data between October 2003 and March 2012. We defined 2 groups: statin users (use for 90 days or greater) and nonusers (no prior statin). A propensity score based on 82 variables was generated to match statin users and nonusers 1:1. Outcomes included incidence of cholelithiasis, biliary tract diseases, and gallbladder procedures.
  
  
  RESULTS
  A total of 43 438 patients were identified; 13 626 (31.4%) were statin users, and 29 812 (68.6%) were nonusers. We matched 6342 pairs of statin users and nonusers based on propensity score. The odds ratios (ORs) in statin users in comparison to nonusers were similar for cholelithiasis (OR = 0.86; 95% CI = 0.73, 1.02), biliary tract disease (OR = 0.85; 95% CI = 0.67-1.08), and gall bladder procedures (OR = 0.85; 95% CI = 0.69, 1.04).
  
  
  CONCLUSIONS
  Statin use was not significantly associated with either an increased or decreased risk of cholelithiasis or gallbladder disease.
authors.affiliation: University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Donald
authors.initials: D
authors.lastname: Martin
authors.affiliation: University of Texas Southwestern Medical Center, Dallas, TX, USA VA North Texas Health Care System, Dallas, TX, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Schmidt
authors.affiliation: University of Texas Southwestern Medical Center, Dallas, TX, USA VA North Texas Health Care System, Dallas, TX, USA.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Mortensen
authors.affiliation: University of Texas Southwestern Medical Center, Dallas, TX, USA VA North Texas Health Care System, Dallas, TX, USA Ishak.Mansi@va.gov.
authors.forename: Ishak
authors.initials: I
authors.lastname: Mansi
mesh_terms: D000328:Adult; D000368:Aged; D001660:Biliary Tract Diseases / Q000139:chemically induced* / Q000453:epidemiology; D002769:Cholelithiasis / Q000139:chemically induced / Q000453:epidemiology; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000009:adverse effects*; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D057216:Propensity Score; D012189:Retrospective Studies; D012306:Risk
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors
keywords: cholelithiasis; cholesterol; statins