High serum uric acid and risk of nonalcoholic fatty liver disease: A systematic review and meta-analysis

Objectives: Emerging evidence connects serum uric acid (SUA) levels to nonalcoholic fatty liver disease (NAFLD). The objective of this study was to systematically evaluate the association between SUA levels and risk of NAFLD by conducting a meta-analysis of available observational studies. Design and methods: We searched for relevant studies in PubMed, Embase, China National Knowledge Infrastructure, and Wanfang databases until October 2014. All observational studies that evaluated SUA levels and NAFLD risks were included. Pooled adjusted odds ratio (OR) and corresponding 95% confidence intervals (Cl) were calculated comparing the highest to lowest SUA category. Results: Four cross-sectional studies, two prospective studies, and three retrospective studies involving 55,573 participants were identified. In overall risk estimates, the pooled OR of NAFLD occurrence was 1.92 (95% Cl: 1.59-2.31) comparing the highest to lowest SUA levels in a random effect model. Subgroup analysis showed that high SUA levels increased the risk of NAFLD in cross-sectional studies (OR: 2.18; 95% Cl: 1.58-3.03), retrospective studies (OR 1.82; 95% Cl: 1A3-2.33), and prospective studies (OR 1.43; 95% Cl: 1.20-1.71). The risk of NAFLD seemed more pronounced among women (OR 1.85; 95% CI: 1.43-2.38) than among men (OR 1.56; 95% CI: 1.30-1.86). Conclusion: This meta-analysis suggests that increased SUA level is associated with an exacerbated risk of NAFLD. This increased risk is probably independent of conventional NAFLD risk factors. (C) 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.