Association between serum uric acid levels and long-term mortality of metabolic dysfunction-associated fatty liver disease: a nationwide cohort study

Abstract

Background: The association between hyperuricemia and metabolic dysfunction-associated fatty liver disease (MAFLD) remains undetermined. This study aimed to examine the association of serum uric acid (SUA) levels with prevalence and long-term mortality of MAFLD in a nationally representative sample of US adults. Methods: This analysis included 11,177 participants from the Third National Health and Nutrition Examination Survey (NHANES III, 1988–1994) with matched mortality data until 2019. We used logistic regression models to estimate the adjusted odd ratios (ORs) for factors associated with risk of MAFLD, and applied restricted cubic spline (RCS) regression to assess the non-linear associations of SUA levels with all-cause and cause-specific mortality of MAFLD. We also used Cox proportional hazards regression analysis to estimate hazard ratios (HRs) for the mortality. Results: A higher SUA level contributed to a significant increased risk of MAFLD. every 1 mg/dL increment of SUA level was related to 17% (95% CI 9–24%) increased risk of MAFLD. Furthermore, a U-shaped association for males and a J-shaped association for females was discovered between SUA levels and all-cause mortality in participants with MAFLD. Specifically, among males, when SUA > 6.7 mg/dL, the higher SUA showed increased risk of cardio-cerebrovascular disease (CVD) mortality [HR (95% CI): 1.29 (1.05–1.58)]. As for females, only when SUA > 5.5 mg/dL, it showed a significantly positive association with risk of CVD and cancer mortality [HR (95% CI) 1.62 (1.24–2.13) and 1.95 (1.41–2.68)]. Conclusions: Elevated SUA level is significantly associated with an increased risk of MAFLD. Besides, SUA level is also a predictor of long-term mortality of MAFLD.