Brain natriuretic peptide as an integrator of cardiovascular stiffening in hypertension

Abstract

Background Left ventricular (LV) diastolic dysfunction and impairment of aortic elastic properties represent common sequelae of hypertension. We investigated the relationships of these cardiovascular adaptations with brain natriuretic peptide (BNP) levels in newly-diagnosed hypertension. Methods 200 consecutive hypertensives without LV hypertrophy (aged 52 years, 134 males, office BP = 151.4/95.5 mmHg) underwent 24 hour ambulatory BP measurement as well as aortic stiffness and LV diastolic function assessment by means of carotid-femoral pulse wave velocity (c-f PWV) measurement and Tissue Doppler Imaging (TDI), respectively. Based on BNP values patients were classified into tertiles. Results Hypertensives in the highest, compared to those in the lowest BNP tertile had significantly higher 24 h pulse pressure (by 6.2 mmHg, p = 0.002), lower 24 h diastolic BP (by 5.7 mmHg, p = 0.014), decreased Em/Am ratio (by 0.09, p = 0.048) and increased c-f PWV (by 0.7 m/s, p = 0.042). Moreover, hypertensives in the highest, compared with those in the lowest and the medium tertile of BNP, exhibited significantly lower Em (by 1.2 cm/s, p = 0.001 and 1 cm/s, p = 0.004, respectively) and higher E/Em ratio (by 1.3, p = 0.018 and 1.3, p = 0.014, respectively). BNP was significantly associated with E/Em ratio, 24 h pulse pressure and c-f PWV independently from age. Conclusion In hypertensives plasma BNP levels are associated not only with LV diastolic dysfunction but also with aortic stiffening. These findings suggest that BNP even within normal range constitutes a surrogate for cardiovascular functional impairment in the setting of essential hypertension without LV hypertrophy.