Uric acid and chronic kidney disease: new understanding of an old problem.

Although an elevation of serum uric acid level is often associated with chronic kidney disease (CKD), it remains controversial whether hyperuricemia per se is a true risk factor for the development or aggravation of CKD. Recent epidemiologic studies in healthy populations or in subjects with established kidney disease have reported the independent role of uric acid in lowering glomerular filtration rate and increasing the risk for new-onset kidney disease. Furthermore, lowering uric acid in patients with established renal disease has been reported to stabilize renal function independent of other confounders, suggesting a causative role of elevated uric acid in progression of CKD, rather than as an incidental finding related to CKD severity. In this manuscript we will discuss the potential role of uric acid in the development and aggravation of CKD based on epidemiologic, clinical and experimental studies. Given the worldwide epidemic of CKD, the importance of identifying modifiable risk factors of CKD, and the clinical implication of hyperuricemia in CKD, we propose large randomized clinical trials to investigate whether uric acid-lowering therapy can slow the progression of CKD.