Alteration of normal level of serum urate may contribute to decrease in estimated glomerular filtration rate decline in healthy Japanese men

Serum uric acid (SUA) levels have a linear relationship with the estimated glomerular filtration rate (eGFR). It is unclear whether further changes, subsequent to normal level of SUA can attenuate eGFR decline in a healthy population, so we aimed to determine the normal level of SUA that can contribute to preventing kidney dysfunction. In this retrospective cohort study from Japan, annual health checkup data from 2009 to 2014 was collected. After propensity score matching (1:1), data from 2,634 individuals with basal SUA ≤7.0 mg/dL (normal; mean age, 39 y; mean eGFR, 80.8 mL/min/1.73 m2) and 1,642 individuals with basal SUA >7.0 mg/dL (elevated; mean age, 42 y; mean eGFR, 75.0 mL/min/1.73 m2) were collected to determine the relationship between followed-up SUA level and the rate of change in eGFR. In individuals with normal level SUA at baseline, the elevation of SUA (>7.0 mg/dL) accelerated eGFR decline compared to those with normal SUA levels at 5-year follow-up (−4.1 ± 9.6% vs −9.9 ± 9.0%, p < .0001). Digression of SUA level (≤7.0 mg/dL) reduced eGFR decline compared with persistent SUA level over 7.0 mg/dL (−1.5 ± 11.5% vs −7.0 ± 10.1, p < .0001). In multiple linear regression analysis, there was strong association between the rate of change in SUA and eGFR in individuals with basal SUA ≤7.0 and >7.0 mg/dL (standardized coefficient; −0.3348, p < .001 and −.2523, p < .001, respectively). Subsequent to normal level of SUA (under 7.0 mg/dL) may contribute to a decrease in eGFR decline in apparently healthy men.