Hyperuricemia in diabetic nephropathy: pathogenesis, diagnosis, and treatment

Diabetic nephropathy is a severe complication of diabetes mellitus, leading to chronic kidney disease. The prevalence of kidney involvement in patients with diabetes mellitus exceeds 20%. This condition is often associated with various metabolic disorders, among which hyperuricemia is regarded as an independent risk factor for the progression of kidney disease and cardiovascular complications. Despite improvements in glycemic control, blood pressure management, and the widespread use of nephroprotective agents, the trend toward end-stage renal disease persists. In this context, controlling serum uric acid levels may represent one of the approaches to the pathogenetic treatment of diabetic kidney disease. In the domestic standards of specialized diabetes care, only monitoring of uric acid levels is recommended. Russian clinical guidelines for chronic kidney disease recommend treating hyperuricemia at a specific stage of kidney disease. International guidelines for chronic kidney disease base the approach to therapy on the presence of clinical symptoms of hyperuricemia and, in asymptomatic cases, recommend against using urate-lowering drugs to slow nephropathy progression. The interrelationships between hyperuricemia, diabetes mellitus, and kidney disease are examined, considering not only the pathological but also the physiological role of uric acid in vivo. Threshold values of serum uric acid in patients with diabetes mellitus, aspects of hyperuricemia diagnosis, and its association with the risk of developing and/or progressing diabetic kidney disease are discussed. The results of studies on the effects of various classes of drugs with direct and indirect hypouricemic effects on kidney function in diabetes mellitus are reviewed. An attempt is made to clarify which patient group, for what reasons, and under what conditions may benefit most from urate-lowering therapy.