Effects of Statin Use on the Development and Progression of Nonalcoholic Fatty Liver Disease: A Nationwide Nested Case-Control Study

INTRODUCTION: The use of statins in nonalcoholic fatty liver disease (NAFLD) may reduce cardiovascular morbidity, although their effect on NAFLD itself is not well known. We aimed to investigate the role of statins on the development of de novo NAFLD and progression of significant liver fibrosis. METHODS: This study included 11,593,409 subjects from the National Health Information Database of the Republic of Korea entered in 2010 and followed up until 2016. NAFLD was diagnosed by calculating fatty liver index (FLI), and significant liver fibrosis was evaluated using the BARD score. Controls were randomly selected at a ratio of 1:5 from individuals who were at risk of becoming the case subjects at the time of selection. RESULTS: Among 5,339,901 subjects that had a FLI < 30 and included in the non-NAFLD cohort, 164,856 subjects eventually had NAFLD developed. The use of statin was associated with a reduced risk of NAFLD development (adjusted odds ratio [AOR] 0.66; 95% confidence interval [CI] 0.65–0.67) and was independent of associated diabetes mellitus (DM) (with DM: AOR 0.44; 95% CI 0.41–0.46, without DM: AOR 0.71; 95% CI 0.69–0.72). From 712,262 subjects with a FLI > 60 and selected in the NAFLD cohort, 111,257 subjects showed a BARD score ≥ 2 and were defined as liver fibrosis cases. The use of statins reduced the risk of significant liver fibrosis (AOR 0.43; 95% CI 0.42–0.44), independent of DM (with DM: AOR 0.31; 95% CI 0.31–0.32, without DM: AOR 0.52; 95% CI 0.51–0.52). DISCUSSION: In this large population-based study, statin use decreased the risk of NAFLD occurrence and the risk of liver fibrosis once NAFLD developed.