OBJECTIVES: Other than weight-related conditions, risk factors for non-alcoholic fatty liver disease (NAFLD) are not well defined. We investigated the association of gallstones and cholecystectomy with NAFLD in a large, national, population-based study. METHODS: Among adult participants in the third US National Health and Nutrition Examination Survey, 1988-1994, ultrasonography for gallstone disease was performed, and videotapes were subsequently evaluated for NAFLD. Odds ratios (ORs) for the association of gallstone disease with NAFLD were calculated using logistic regression analysis to adjust for common associated factors. RESULTS: Among 12,232 participants without viral hepatitis or significant alcohol intake, the prevalence of gallstones was 7.4%, cholecystectomy 5.6%, and NAFLD 20.0%. Participants with cholecystectomy had higher age-sex-adjusted prevalence of NAFLD (48.4%) than those with gallstones (34.4%) or without gallstone disease (17.9%) (P<0.01 for all comparisons). Controlling for numerous factors associated with both NAFLD and gallstone disease, multivariate-adjusted analysis confirmed the association of NAFLD with cholecystectomy (OR=2.4; 95% confidence interval (CI): 1.8-3.3), but not with gallstones (OR=1.1; 95% CI: 0.84-1.4). CONCLUSIONS: The association of NAFLD with cholecystectomy, but not with gallstones, indicates that cholecystectomy may itself be a risk factor for NAFLD.
OBJECTIVES: Other than weight-related conditions, risk factors for non-alcoholic fatty liver disease (NAFLD) are not well defined. We investigated the association of gallstones and cholecystectomy with NAFLD in a large, national, population-based study. METHODS: Among adult participants in the third US National Health and Nutrition Examination Survey, 1988-1994, ultrasonography for gallstone disease was performed, and videotapes were subsequently evaluated for NAFLD. Odds ratios (ORs) for the association of gallstone disease with NAFLD were calculated using logistic regression analysis to adjust for common associated factors. RESULTS: Among 12,232 participants without viral hepatitis or significant alcohol intake, the prevalence of gallstones was 7.4%, cholecystectomy 5.6%, and NAFLD 20.0%. Participants with cholecystectomy had higher age-sex-adjusted prevalence of NAFLD (48.4%) than those with gallstones (34.4%) or without gallstone disease (17.9%) (P<0.01 for all comparisons). Controlling for numerous factors associated with both NAFLD and gallstone disease, multivariate-adjusted analysis confirmed the association of NAFLD with cholecystectomy (OR=2.4; 95% confidence interval (CI): 1.8-3.3), but not with gallstones (OR=1.1; 95% CI: 0.84-1.4). CONCLUSIONS: The association of NAFLD with cholecystectomy, but not with gallstones, indicates that cholecystectomy may itself be a risk factor for NAFLD.