Aims: Ramipril and candesartan have distinct mechanisms of action to improve endothelial function. Therefore, we hypothesized that combination therapy has additive beneficial effects to simultaneously improve endothelial dysfunction and adipocytokine profiles in patients with hypertension.
Methods and results: Thirty-four patients were given ramipril 10 mg and placebo, ramipril 10 mg and candesartan 16 mg, or candesartan 16 mg and placebo daily in a randomized, double-blind, placebo-controlled cross-over trial with three treatment arms and two washout periods (each 2 months). Ramipril, candesartan, or combination therapy reduced blood pressure, improved flow-mediated dilation, and increased plasma adiponectin levels when compared with baseline values. However, combination therapy improved these outcome measures to a greater extent than either ramipril or candesartan alone (P < 0.001 and P = 0.016 for systolic and diastolic blood pressure, P < 0.001 and P = 0.048 for flow-mediated dilation and adiponectin levels by ANOVA). In addition, combination therapy reduced plasma leptin levels to a greater extent than either ramipril or candesartan alone (P = 0.042 by ANOVA). There were correlations between percent changes in adiponectin levels and percent changes in insulin sensitivity (determined by QUICKI) (r = 0.319, P = 0.066) following ramipril therapy, percent changes in QUICKI (r = 0.374, P = 0.029) following combination therapy, and percent changes in QUICKI (r = 0.607, P < 0.001) following candesartan therapy.
Conclusion: Ramipril in combination with candesartan improves blood pressure, endothelial function, and adipocytokine profiles to a greater extent than monotherapy with either drug in hypertensive patients.