Relationship between serum uric acid level and all-cause and cardiovascular mortality in population with obesity.

BACKGROUND: We aimed to investigate the association between serum uric acid (SUA) and all-cause or cardiovascular mortality among participants with obesity. METHOD: All participants were included from the 1999 to 2014 National Health and Nutrition Examination Survey with follow-up mortality assessment through 31 December 2015. Cox proportional hazards models were built to estimate adjusted HRs and 95% CIs for mortality according to baseline uric acid in quartiles. Obesity was defined as body mass index ≥30 (kg/m2). Generalised additive model (GAM) and two-piecewise linear regression models were performed to explore any non-linearity in associations. RESULTS: There were 12 637 adults with obesity eligible for analysis. There were 999 (7.91%) all-cause and 147 (1.16%) cardiovascular mortality occurred during the mean follow-up of 98.11 months. Comparing with the lowest quartile of SUA, the highest SUA group did not have significant association with all-cause (HR 1.08, 95% CI 0.76 to 1.52) and cardiovascular mortality (HR 1.63, 95% CI 0.58 to 4.53) after adjusting for various confounding factors. GAM and two-piecewise linear regression model demonstrated a non-linearly relationship between SUA and all-cause mortality, and the corresponding cut-off point was 6.5 mg/dL. However, there is no significant relationship between uric acid and cardiovascular death on both sides of the cut-off value of 6.1 mg/dL. CONCLUSIONS: SUA showed a J-shaped relationship with all-cause mortality, but no significant with cardiovascular mortality in adults with obesity.