Nephropathy of type 2 diabetes is the leading cause of end stage renal disease (ESRD) world-wide and is associated with a dramatic excess cardiovascular morbidity and mortality. Two randomized trials found that angiotensin II receptor blockers (ARBs) reduce the incidence of ESRD by about 30%, but have no appreciable effects on cardiovascular mortality. Available data suggest that ACE inhibitors might be similarly renoprotective and even more cardioprotective, but large scale trials on ACE inhibitors, alone or combined with ARBs, in overt nephropathy of type 2 diabetes are missing.

This study will compare the effects, at comparable blood pressure control (systolic/diastolic <130/80 mmHg), of dual renin-angiotensin-system (RAS) blockade by half dose of benazepril and valsartan combination therapy as compared to single RAS blockade by benazepril or valsartan alone at full dose, 20 mg and 160 mg respectively, on ESRD and cardiovascular events in high-risk patients with type 2 diabetes and overt nephropathy, defined as serum creatinine >1.8 mg/dl and < 3.2 mg/dl and urine spot A/C > 2000 mg/g. The relationships between renal and cardiovascular outcomes will also be evaluated.

120 patients will be treated for at least 3 years. At comparable blood pressure control, the study is expected to show a more effective reduction in ESRD and cardiovascular events with combined than with single drug ACE inhibitor or ARB therapy. As compared to ARB, ACE inibitor therapy is expected to have a similar effect on ESRD, but a superior cardioprotective effect. Applied to clinical practice, the findings should help reducing renal and cardiovascular complications, and related treatment costs, of type 2 diabetes.