NEW YORK (Reuters Health) - Combining the angiotensin-converting enzyme (ACE) inhibitor ramipril and the angiotensin II type 1 receptor-blocker (ARB) candesartan lowers blood pressure and improves endothelial function to a greater extent than either drug alone, Korean investigators report.

Thirty-four patients with hypertension were randomized to ramipril 10 mg plus placebo, candesartan 16 mg plus placebo, or ramipril 10 mg and candesartan 16 mg in a three-arm cross-over trial. Each treatment period was two months in length, with a two-month washout period between each treatment.

All three treatment arms resulted in lower blood pressure, but combination therapy had a greater antihypertensive effect than either agent alone, Dr. Kwang Kon Koh and associates at Gachon Medical School in Incheon report in the June 1st issue of the European Heart Journal:

Specifically, ramipril therapy lowered blood pressure from a mean of 155/95 mm Hg at baseline to 142/88 mm Hg after treatment; candesartan lowered blood pressure from 156/95 mm Hg at baseline to 137/85 mm Hg after treatment; and combination therapy lowered blood pressure from a mean of 157/96 mm Hg at baseline to 131/80 mm Hg after treatment.

In addition to lowering both systolic and diastolic blood pressure, the three treatment arms improved flow-mediated dilation and increased plasma adiponectin levels. Again, combination therapy improved these outcome measures to a greater extent than either ramipril or candesartan alone, Dr. Koh and colleagues report.

There were correlations between percent changes in adiponectin levels and percent changes in insulin sensitivity with monotherapy and combination therapy.

Combining the ACE inhibitor and the ARB, "which target different aspects of the renin angiotensin system, may have merit in the treatment of both cardiovascular and metabolic disease, which are characterized by reciprocal relationships between endothelial dysfunction and insulin resistance," the investigators conclude.

Euro Heart J 2007;28:1440-1447.