Determinants of plasma brain natriuretic peptide levels in untreated hypertensive patients

Abstract

Background: Plasma brain natriuretic peptide (BNP) level is elevated in patients with left ventricular (LV) hypertrophy reflecting not only altered LV geometry but LV systolic and/or diastolic dysfunction. However, the values and limitations of BNP measurements are unclear in patients with untreated hypertension. In this study, plasma BNP level was compared with LV geometric and functional characteristics in patients with untreated hypertension.

Methods: Plasma BNP level was measured in 115 patients with untreated hypertension (72 males, 43 females, aged 60 ± 12 years). Routine echo parameters of LV geometry and LV systolic and diastolic performance were also determined.

Results: LV ejection fraction was 67 ± 6% and plasma BNP level was 32 ± 30 pg/ml. Plasma BNP levels correlated with age, LV mass index (LVMI), and mitral E velocity, respectively (r = 0.46, p < 0.05; r = 0.21, p < 0.05; r = 0.29, p < 0.05, respectively), but not with systolic blood pressure or relative wall thickness (r = 0.01; r = -0.02). Plasma BNP level correlated with E/E' ratio (r = 0.27, p < 0.05, n = 77). When a stepwise multivariate analysis was performed, E velocity was selected in addition to age and LVMI as significant correlates of plasma BNP level.

Conclusions: LVMI and E velocity were independent determinants of plasma BNP level in patients with untreated hypertension. Plasma BNP level is substantially useful for the screening of abnormalities of LV geometry and/or function in patients with untreated hypertension. Additional echocardiography is useful to assess the mechanism of the elevation of plasma BNP level in untreated hypertensive patients.

Keywords: BNP; Echocardiography; Hypertension; Hypertrophy; LV diastolic function.