Effects of nebivolol or irbesartan in combination with hydrochlorothiazide on vascular functions in newly-diagnosed hypertensive patients: The NINFE (Nebivololo, Irbesartan Nella Funzione Endoteliale) study

Background: Arterial hypertension affects endothelial function and arterial stiffness. The angiotensin (AT1) receptor antagonist irbesartan improves endothelial function and arterial stiffness in hypertensive patients. Nebivolol, a beta ₁-selective beta blocker, reduces systemic vascular resistance and stimulates nitric oxide release thus exerting positive effects on vascular function. However, comparative studies on the vascular effects of third generation beta-blockers and AT1 receptor blockers are lacking. Aim of this randomized, double-blind study was to test the hypothesis of non-inferiority of nebivolol to irbesartan, both in association with hydrochlorothiazide, on endothelial function, arterial stiffness and central hemodynamic parameters in patients with arterial hypertension naïve on therapy. Methods: Sixty-five patients were randomized to receive irbesartan/hydrochlorothiazide (150 mg/12.5 mg day) or nebivolol/hydrochlorothiazide (5 mg/12.5 mg day) for 8-weeks. Endothelial function, pulse wave velocity, augmentation index, central and brachial blood pressures were measured at baseline and at the end of the study. Results: Systolic and diastolic central blood pressure, as well as brachial arterial pressure, decreased to a similar extent after both treatments. Similar changes in endothelial function between groups were detected at the end of the study. A significant reduction in pulse wave velocity, central blood pressure, and augmentation index adjusted for heart rate, was found in both the treatment groups at the end of the study, without significant differences between groups. Conclusions: The results of this study confirm the hypothesis of non-inferiority of short-term treatment with nebivolol compared to irbesartan, both in association with hydrochlorothiazide, on endothelial function, arterial stiffness and central hemodynamic parameters in hypertensive patients naïve on therapy.