Abstract P106: Effects of Aldosterone Excess and Sodium on Dipping Patterns in Resistant Hypertensive Patients

Abstract

Background: High dietary sodium intake and aldosterone excess have been independently linked to increased cardiovascular morbidity and mortality. In addition, a large body of literature indicates that aldosterone excess contributes importantly to antihypertensive treatment resistance and is associated with higher 24- hour ambulatory blood pressure (BP) levels. Objective: This study was designed to determine if high dietary sodium intake, and hyperaldosteronism combine to mediate the development of abnormal diurnal BP patterns including nocturnal hypertension and dipping BP patterns. Methods: A single-center cohort of 326 African American (AA) and Caucasian resistant hypertensive patients were prospectively evaluated by assessing 24-hr urinary aldosterone (UAldo), plasma renin activity (PRA), sodium (UNa + ) levels, and 24-hr ambulatory blood pressure monitoring (ABPM). Daytime, night-time, and 24-hr BP and dipping patterns were determined. High sodium excretion was defined as UNa + = 200 mEq/24hr and hyperaldosteronism was defined as UAldo = 12 μg/24hr and PRA ≤ 1 ng/ml/hr. Results: There was no difference in ABPM and dipping patterns when comparing the normal versus high sodium group. However, patients without high sodium excretion had better nocturnal (p=0.024) and 24- hour BP control (p=0.036). Furthermore, there was no difference in ABPM patterns when comparing patients with high versus normal sodium excretion with hyper versus non- hyperaldosteronism. Interestingly, in the group with hyperaldosteronism, patients with normal sodium excretion had improved dipping patterns, but only in the dipper group (p=0.016). Conclusions: High dietary sodium intake contributes to increased nocturnal hypertension and poor 24-h BP control, but there does not seem to be a significant relationship between hyperaldosteronism and high dietary sodium intake. This data suggests that improvements in dietary sodium intake will lead to better control of nighttime BP and 24-h BP control and therefore reduces the risk of cardiovascular disease. Further studies are underway comparing these relationships in males versus females, and AAs versus Caucasians.