Introduction: Several studies have shown that statins suppress the progression of diabetic nephropathy. However, few reports have directly compared the renoprotective effects between potent and conventional statins.
Materials and methods: Patients with diabetic nephropathy, selected as those with a serum creatinine level of 0.9-1.5 mg/dL and simultaneously having either microalbuminuria or positive proteinuria, were randomly assigned to one of three groups: a conventional diet therapy group, a group given 10 mg of pravastatin and a group given 10 mg of atorvastatin. Renal function was evaluated before and after a 12-month period of therapy.
Results: The atorvastatin group had a significant decrease in low-density lipoprotein cholesterol at 3 months and thereafter compared with the other groups. The urinary albumin-to-creatinine ratio significantly decreased in the atorvastatin group; the degree of this decrease was significantly greater than that in the diet therapy group. The kidney function estimated with cystatin C (CysC) and the estimated glomerular filtration rate calculated from CysC were significantly preserved in the atorvastatin group compared with the pravastatin group. In a multivariate regression analysis, the use of atorvastatin was the only explanatory variable for the changes in CysC; this was independent of changes in low-density lipoprotein cholesterol.
Conclusions: Atorvastatin is more effective than pravastatin for the prevention of increase in CysC, and this renoprotective effect was considered to a result of the pleiotropic effect of atorvastatin independent of its lipid-lowering effect. This study was registered with UMIN (no. UMIN 000001774).
Keywords: Early diabetic nephropathy; Renoprotective effects; Statins.