Association Between Serum Uric Acid and Non-alcoholic Fatty Liver Disease in Non-obese Young Population: A Prospective Cohort Study

Objective: The prevalence of non-alcoholic fatty liver disease (NAFLD) is gradually increasing among non-obese people and shows a trend of younger age. The objective of this study was to investigate the potential association between serum uric acid (SUA) and NAFLD in a non-obese young population.

Patients and methods: The study recruited 10,938 participants without NAFLD (18 ≤ age < 45,18.5 ≤ BMI < 25) in 2006. After a median follow-up of 9.95 years, 4835 (44.20%) participants were diagnosed with NAFLD. According to the baseline SUA level, the research subjects were divided into 4 groups by the quartile method. The association between SUA and NAFLD was predicted using the Kaplan -Meier survival curve and Cox hazard regression model.

Results: After adjusting for all the confounders, the HRs and 95%CI for NAFLD in the quartile 2, quartile 3 and quartile 4 were 1.095(1.004 ~ 1.193), 1.195(1.095 ~ 1.304) and 1.409(1.289 ~ 1.541). The restrictive cubic spline (RCS) functions confirmed the existence of a non-linear association between the initial SUA and NAFLD (non-linearity association P < 0.05). Kaplan-Meier Survival Curve shows that the risk of NAFLD increased with increasing levels of SUA. The cumulative incidences of the four groups were 46.19, 51.99, 56.52 and 65.87%, respectively (log-rank test P < 0.001).

Conclusion: It has been confirmed through a prospective cohort study that in non-obese young population, SUA can serve as an independent predictor of NAFLD. An increase in SUA within the physiological range, even if it doesn't reach the level of hyperuricemia, can impose a significant burden on the occurrence of NAFLD.

Trial registration: Trial registration number: ChiCTR-TNC-11001489, registration site: http://www.chictr.org.cn/index.aspx .