Impact of Uric Acid Levels on Mortality and Cardiovascular Outcomes in Relation to Kidney Function

<b>Background</b>: Uric acid levels are linked to cardiovascular outcomes and mortality, especially in chronic kidney disease (CKD). However, their impact across varying kidney function remains unclear. <b>Methods</b>: We conducted a retrospective cohort study using the Observational Medical Outcomes Partnership Common Data Model (OMOP-CDM) database from a single center. Adult patients with at least one serum uric acid measurement between 2002 and 2021 were included and categorized by estimated glomerular filtration rate (eGFR): normal kidney function (≥90 mL/min/1.73 m²), mild dysfunction (60-89 mL/min/1.73 m²), moderate dysfunction (30-59 mL/min/1.73 m²), and advanced dysfunction (<30 mL/min/1.73 m²). The primary outcome was all-cause mortality with secondary outcomes being myocardial infarction (MI) and heart failure (HF). <b>Results</b>: A total of 242,793 participants were analyzed. Uric acid levels showed a U-shaped association with all-cause mortality in advanced kidney dysfunction, where both low (<3 mg/dL) and high (>10 mg/dL) levels increased mortality risk. In mild kidney dysfunction, lower uric acid levels were linked to better survival. HF risk increased linearly with higher uric acid, particularly in normal kidney function, while no significant association was found between uric acid and MI in any group. <b>Conclusions</b>: Uric acid levels are associated with mortality in a U-shaped pattern for advanced kidney dysfunction, while lower levels appear protective in mild dysfunction. These findings suggest the need for personalized uric acid management in CKD patients based on their kidney function.