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.