Relationships between the antihypertensive effects of bisoprolol and levels of plasma atrial natriuretic peptide in hypertensive patients

Previous studies have demonstrated that beta-blockade increases the levels of plasma atrial natriuretic peptide (ANP), but relationships between this effect and the antihypertensive action of beta-blockade remain unknown. In this study we investigated the amplitude and determinants of bisoprolol-induced ANP increase and the relationships between this increase and the antihypertensive effect of bisoprolol. Nineteen patients with mild to moderate hypertension were included in the study. In the first phase of the study (cross-over, placebo controlled, randomized phase), the effects of 10 mg bisoprolol on plasma ANP at rest and during exercise were compared to placebo. The antihypertensive action of bisoprolol was then evaluated after a 2-week period of treatment (10 mg/day) using ambulatory blood pressure monitoring. Bisoprolol significantly increased plasma ANP level at rest (from 30.6 ± 20.5 to 42.8 ± 35.6; P < 0.05) and also during exercise (from 54.7 ± 44.3 to 119.1 ± 159.9; pg/mL ± SD; P < 0.05). Plasma ANP at rest was not significantly correlated with left ventricular mass. After the 15 days of treatment, the bisoprolol-induced daytime diastolic blood pressure reduction was significantly correlated to the initial bisoprolol-induced plasma ANP increase (r=0.49, P=0.035). These results suggest that the antihypertensive effect of beta-blocking agents could be partly mediated by an increase of ANP release.