Hyperuricemia accelerates renal dysfunction due to hypertensive nephrosclerosis: the TAMA MED Project-CKD

BACKGROUND: Nephrosclerosis has become an increasingly common underlying cause of renal replacement therapy worldwide. Hypertension is the primary cause of nephrosclerosis; however, other complex factors are believed to contribute to its onset and progression. In this study, we aimed to investigate whether hyperuricemia is a risk factor for the onset of chronic kidney disease and for progression of renal dysfunction. Additionally, we sought to determine whether the coexistence of hypertension and hyperuricemia exacerbates these risks. METHODS: A follow-up survey was conducted among 11,043 individuals aged 40–74 years in Tama City who underwent specific health checkups in 2016 and continued to receive health checkups for up to 6 years. We investigated the effects of hyperuricemia and hypertension at baseline on the subsequent development of proteinuria and decline in renal function. RESULTS: Elevated uric acid levels in both men and women were not associated with the onset of proteinuria; however, they were identified as risk factors for estimated glomerular filtration rate (eGFR) falling below 60 mL/min/1.73 m² during follow-up, with cutoff values of 5.4 mg/dL for men and 4.6 mg/dL for women. Even in the presence of hypertension, elevated uric acid levels further increased the risk of eGFR falling below 60 mL/min/1.73 m². Additionally, hyperuricemia was an associated factor for a > 1.5-fold increase in serum creatinine levels during follow-up, with cutoff values of 7.1 mg/dL for men and 5.2 mg/dL for women. The coexistence of hyperuricemia and hypertension further amplified the risk of a > 1.5-fold increase in serum creatinine levels. CONCLUSION: The combination of hypertension and hyperuricemia appears to increase the risk of renal function deterioration due to nephrosclerosis. CLINICAL TRIAL NUMBER: Not applicable.