The association between serum uric acid and renal damage in a community-based population: The Takahata study

Background: Hyperuricemia is a risk factor for end-stage renal disease. This study examined the association between serum uric acid and renal damage in a community-based population. Methods: In this study 3126 subjects without renal insufficiency were recruited at baseline and were followed for one year. The urinary albumin-creatinine ratio (UACR) and β₂-microglobulin- creatinine ratio (UBCR) in morning spot urine samples were used as indices of either glomerular (UACR) or tubular (UBCR) damage. Results: The mean value of serum uric acid (mg/dL) was 5.8 ± 1.3 (SD) in men and 4.5 ± 1.1 in women. In cross-sectional analysis the increased serum uric acid levels were accompanied by higher UACR values in both men and women (P < 0.01). In contrast, UBCR values were reduced when uric acid levels increased in both men and women (P < 0.01). Multivariate analysis revealed that albuminuria (UACR ≥ 30 mg/g) was significantly associated with increased uric acid (≥7 mg/dL for men, ≥6 mg/dL for women). High UBCR (≥300 μg/g) was negatively associated with uric acid in men, but not in women, after adjustment for possible confounders. In longitudinal analysis in 1388 subjects multiple linear regression analysis showed that uric acid at baseline was an independent factor for one-year increase of UACR [coefficient 4.80 (95 % confidence interval 0.40-9.33) (mg/g) per 1 mg/dL increase in uric acid, P = 0.033]. Conclusion: This study showed that serum uric acid concentration was positively associated with UACR, suggesting that uric acid may be related to glomerular damage in a community-based population.