Serum Uric Acid and Mortality Risk in Chronic Kidney Disease: A Dose-Response Analysis.

Background/Objectives: Hyperuricemia is highly prevalent in chronic kidney disease (CKD). It has been linked to increased cardiovascular and mortality risk. However, its independent prognostic significance and dose-response relationship with adverse outcomes remain incompletely understood. Methods: This retrospective cohort study included 794 patients with CKD. Hyperuricemia was defined using sex-specific thresholds. The association between hyperuricemia, cardiac events and mortality was tested using a multivariable logistic regression test. Serum uric acid was analyzed as both a categorical and a continuous variable to assess dose-response relationships. Results: Hyperuricemia was present in 44.8% of patients. In multivariable analysis, hyperuricemia was associated with increased odds of cardiac events, although this did not reach statistical significance (OR 1.49, 95% CI 0.98-2.27, p = 0.061). However, hyperuricemia independently predicted mortality (OR 1.98, 95% CI 1.04-3.78, p = 0.039), and importantly, a dose-response relationship was observed between serum uric acid and adverse outcomes. Each 100 μmol/L increase in serum uric acid was associated with a 22% increase in cardiac event risk (OR 1.22, p = 0.011) and a 29% increase in mortality risk (OR 1.29, p = 0.004). Quartile analysis revealed that patients in the highest uric acid quartile had more than three-fold higher mortality compared with the lowest quartile (OR 3.13, 95% CI 1.26-7.79, p = 0.014). Conclusions: Hyperuricemia independently predicts mortality and also demonstrates a significant dose-response relationship with adverse outcomes in CKD. The results support serum uric acid as a clinically meaningful biomarker for mortality risk grading in CKD populations.