In addition to uric acid crystalline deposits that aggravate renal damage due to small renal arteries and chronic interstitial inflammation, many epidemiological and animal studies have shown that uric acid causes microangiopathy in the small glomerular access arteries and causes chronic kidney disease. Two large prospective studies in Japan confirmed that uric acid is associated with the development of renal lesions. The risk of renal failure was 8-fold higher in those with blood uric acid >476 μmol/L (8.5 mg/dl) than in those with blood uric acid between 298 and 381 μmol/L (5.0-6.4 mg/dl). The risk of end-stage renal disease was 4-fold and 9-fold higher in men with blood uric acid ≥420 μmol/L (7.0 mg/dl) and women with blood uric acid ≥357 μmol/L (6.0 mg/dl), respectively. However, according to the present findings, the association between blood uric acid and renal failure occurred only in those with normal baseline renal function, and in those with impaired baseline renal function, blood uric acid was not associated with progression to renal failure. Therefore, as with other cardiovascular risk factors, early intervention may be more effective in reducing complications.