For patients with both type 2 diabetes and hypertension, should you choose an ACE inhibitor or an angiotensin-receptor blocker (ARB) for BP control? Two new studies weigh in with different answers.
One was a double-blind, randomized, prospective trial of 1,204 diabetic hypertensive patients in Italy. At the end of the 3.6-year study, those receiving the ACE inhibitor trandolapril (Mavik) 2 mg/day showed a significantly lower risk for developing microalbuminuria — the first sign of diabetic kidney disease — than those taking a calcium channel blocker (verapamil SR, 24 mg/day). And they did so even when their BP remained high.
The verapamil patients had no reduced risk, regardless of how well their BP was controlled. Patients taking both drugs, however, achieved lower BP than those taking either one as monotherapy (J Am Soc Nephrol. 2006: published online ahead of print).
The Italian researchers also found that lowering systolic pressure was more effective in preventing microalbuminuria than lowering diastolic pressure, mean arterial pressure, or pulse pressure.
Meanwhile, in a multicenter, double-blind U.S. trial presented at the recent American Heart Association Scientific Sessions in Chicago, clinicians found that using the ARB valsartan (Diovan) at high dosages also reduces microalbuminuria in patients with type 2 diabetes and hypertension. After 30 weeks, 51% of those taking valsartan 320 mg/day achieved significant reductions in proteinuria vs. 26% of those taking 160 mg/day. Normal protein excretion levels were achieved by 24% of those taking valsartan 640 mg/day vs. 12% of those using 160 mg/day. Currently, the highest approved daily dosage is 320 mg/day. In addition, normal BP (<130/80 mm Hg) was achieved in 75% of those taking valsartan 640 mg plus either amlodipine or hydrochlorothiazide or all three agents. The most common side effects were headache and dizziness.
The latest BP guidelines state that two or more drugs are usually needed to achieve the target goal of 130/80 in diabetic hypertension, and they note that both ACE inhibitors and ARBs “favorably affect the progression of diabetic nephropathy and reduce albuminuria.”