Baseline serum uric acid level as a predictor of cardiovascular disease related mortality and all-cause mortality: a meta-analysis of prospective studies.

ABSTRACT

OBJECTIVE: Serum uric acid (SUA) levels have been used to predict cardiovascular and all-cause mortality event, but the data have yielded conflicting results. We investigated whether SUA was an independent predictor for cardiovascular or all-cause mortality with prospective studies by meta-analysis. METHODS: Pubmed and Embase were searched without language restrictions for publications available till April 2013. Only prospective studies on cardiovascular or all-cause mortality related to SUA levels were included. Pooled adjust relative risk (RR) and corresponding 95% confidence intervals (CI) were calculated separately for the highest vs. lowest category or the lowest vs. middle category. RESULTS: For the highest SUA, eleven studies with 172,123 participants were identified and analyzed. Elevated SUA increased risk of all-cause mortality (RR 1.24; 95% CI 1.09-1.42) and cardiovascular mortality (RR 1.37; 95% CI 1.19-1.57). Subgroup analyses showed that elevated SUA significantly increase the risk of all-cause mortality among men (RR 1.23; 95% CI 1.08-1.42), but not in women (RR 1.05; 95% CI 0.79-1.39). Risk of cardiovascular mortality appeared to be more pronounced among women (RR 1.35; 95% CI 1.06-1.72). The association between extremely low SUA and mortality was reported in three studies; we did not perform a pooled analysis because of high degree of heterogeneity in these studies. CONCLUSIONS: Baseline SUA level is an independent predictor for future cardiovascular mortality. Elevated SUA appears to significantly increase the risk of all-cause mortality in men, but not in women. Whether low SUA levels are predictors of mortality is still inconclusive.