Serum uric acid and chronic kidney disease: the Severance cohort study.

BACKGROUND Both serum uric acid (SUA) and chronic kidney disease (CKD) are associated with the risk of cardiovascular disease; however, it is unclear whether SUA independently increases the risk of CKD based on longitudinal data. METHODS To investigate the relationship between SUA levels and CKD development, we initiated a 10.2-year prospective cohort study. Data from 14 939 Koreans, 20-84 years of age, who completed a questionnaire and medical examination at the Severance Health Promotion Center were evaluated. The outcome of interest, CKD, was defined as an estimated glomerular filtration rate (GFR) of <60 mL/min/1.73m(2) via the simplified Modification of Diet in Renal Disease equation. RESULTS A multivariate Cox proportional hazard model, controlling for age, life style and other cardiovascular risk factors, showed an increased risk of developing CKD for men [hazard ratio (HR) 2.1; 95% confidence interval (CI) 1.6-2.9] and women (HR = 1.3; 95% CI = 1.0-1.8) in the highest quartiles of SUA compared to their counterparts in the lowest quartiles. The relationship between SUA and CKD was linear and stepwise in men. The HRs for renal function Grade 2 (75-89.9 mL/min/1.73m(2)), Grade 3 (60-74.9 mL/min/1.73m(2)) and Grade 4 (<60 mL/min/1.73m(2)) increased with an increase in SUA quartiles as compared to the baseline GFR group (Grade 1, ≥90 mL/min/1.73m(2)). CONCLUSIONS Higher SUA levels increased the risk of CKD, suggesting that at least part of the reported association between SUA and cardiovascular disease may be connected to CKD.