Dual inhibition with losartan and aliskiren: a promising therapeutic option for type 2 diabetic nephropathy?

This Practice Point commentary discusses the findings and limitations of a randomized, double-blind study conducted by Parving and colleagues. The study evaluated the renoprotective effects of dual blockade of the renin-angiotensin-aldosterone system by adding aliskiren (an oral, direct renin inhibitor) or placebo to treatment with 100 mg daily losartan in patients who had hypertension and type 2 diabetes with nephropathy. Addition of daily aliskiren for 6 months (150 mg/day for 3 months and 300 mg/day for 3 months) reduced the mean urinary albumin:creatinine ratio by 20% (P <0.001), with a reduction of 50% or more in 24.7% of the patients who received aliskiren versus only 12.5% of those who received placebo (P <0.001). At study end, mean blood pressure levels were only slightly lower in the aliskiren group than in the placebo group (2/1 mmHg lower). The authors concluded that aliskiren might have renoprotective effects that are independent of its blood-pressure-lowering effect in patients who have hypertension, type 2 diabetes and nephropathy and are receiving the recommended renoprotective treatment.