Higher serum uric acid levels and risk of all-cause mortality in general population: a systematic review and meta-analysis.

BACKGROUND

Population-based studies have reported a relationship between high serum uric acid (SUA) levels and all-cause mortality; however, findings are inconsistent. To address this issue, we conducted a meta-analysis of general population-based studies.

METHODS

A systematic search was conducted in PubMed, Ovid Medline, EMBASE, and Web of science to identify relevant peer-reviewed articles using pre-specified search terms. Population-based cohort studies investigating the association between SUA levels and all-cause mortality were included. Risk ratios (RR) for all-cause mortality were calculated for higher and lower SUA levels based on data reporting on exposure and outcome. A meta-analysis based on a log-transformed random effect maximum likelihood model was used to obtain summary risk estimates. Heterogeneity was assessed through subgroup analysis and meta-regression of the study-level covariates.

RESULTS

Thirty-four studies with more than 2.5 million participants were identified and analysed. Higher SUA levels were associated with an increased risk of all-cause mortality (RR: 1.32; 95 % confidence intervals (CIs):1.26-1.39, p < 0.001). The risk of mortality was higher in women (RR:1.91; 95 %CI:1.40-2.61, p < 0.001) compared to men (RR:1.16; 95 %CI:1.08 1.24, p < 0.001). Subgroup analyses suggested that middle-aged adults (RR: 1.52, 95 %CI: 1.35-1.68), individuals living in OECD countries (RR:1.39, 95 %CI:1.28-1.49) and those of Caucasian ethnicity (RR:1.43, 95 %CI:1.35-1.51) reported a greater impact of elevated SUA levels on all-cause mortality.

CONCLUSIONS

Higher SUA levels were associated with a significant increase in the risk of all-cause mortality, with women appearing to be at greater risk than men. These findings highlight the need for research into mechanisms underlying the association between SUA and mortality and the reason for the sex difference identified.