Prevention and Treatment of Diabetic Nephropathy

Aggressive treatment of hypertension is effective in reducing both microvascular and macrovascular complications in type 2 diabetes, with target BP < 130/80 mmHg being recommended. Angiotensin-converting enzyme inhibitors were found to be more effective than the other traditional agents in reducing the onset of clinical proteinuria in individuals with both type 1 and type 2 diabetes and incipient nephropathy. However, small trials on patients with type 2 diabetes and overt nephropathy failed to demonstrate a specific renoprotective role for this class of drugs. The aim of the Program for Irbesartan Mortality and Morbidity Evaluation was to ascertain whether angiotensin II receptor blockers are effective in both preventing the development of clinical proteinuria and delaying the progression of nephropathy in type 2 diabetes. The Irbesartan in Patients with Type 2 Diabetes and Microalbuminuria (IRMA) Study showed that, as compared with conventional therapy, irbesartan is better at preventing the development of clinical proteinuria and at restoring normoalbuminuria for comparable BP control in patients with incipient nephropathy. The Irbesartan Diabetic Nephropathy Trial showed that irbesartan is more effective than traditional antihypertensive therapies in reducing the progression toward ESRD in patients with type 2 diabetes and overt nephropathy regardless of changes in BP. Moreover, secondary analysis of the Irbesartan Diabetic Nephropathy Trial showed that the achieved systolic pressure as well as baseline and current proteinuria significantly predict renal outcomes. In conclusion, the results of the Program for Irbesartan Mortality and Morbidity Evaluation demonstrate that irbesartan significantly prevents the development of clinical proteinuria in individuals with microalbuminuria and delays the progression of nephropathy in individuals with proteinuria. Moreover, the renoprotective effects of irbesartan go beyond its effect on BP.