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

Abstract

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.