GFR-Adjusted Uric Acid Is Superior in Prediction of All-Cause Mortality Compared with Uric Acid or Uric Acid/Serum Creatinine

Background: Elevated uric acid (UA) levels and serum UA to serum creatinine ratio (sUA/sCr) are associated with increased cardiovascular risk. We investigated GFR, age and sex-adjusted UA levels (eUA) to further increase precision in cardiovascular risk prediction. Methods: The eUA formula was validated in the LURIC cohort. Due to GFR restrictions, a subpopulation of 2654 patients was evaluated. Outcome variables (mortality, cardiovascular events, heart failure NYHA > II) were analyzed in a risk group (eUA < UA) compared to the control group (eUA > UA). Uni- and multivariate regression analysis was performed for known risk factors as well as UA, eUA and sUA/sCr. Results: eUA levels were calculated on the basis of the presented eUA formula. Mortality (OR 1.35; 95 % CI 1.09 -1.67; p = 0.006) and heart failure NYHA > II (OR 1.91; 95 % CI 1.53 – 2.39; p < 0.001) were significantly increased in patients within the risk group (eUA < UA). Multivariate analysis revealed a better prediction of mortality with eUA (OR 7.41; 95 % CI 3.15 -17.47; p<0.001) compared to sUA/sCr (OR 1.12; 95 % CI 1.05 – 1.19; p < 0.001) or UA (OR 1.09; 95 % CI 1.02 – 1.16; p = 0.006) after adjustment for known cardiovascular risk factors. Cardiac events or heart failure NYHA > II was statistically not associated with eUA levels. Conclusion: Assessment of the newly calculated eUA identifies patients with a particularly increased cardiovascular risk. eUA is superior in predicting mortality compared to established markers such as UA or sUA/sCr.