Aldosterone excess and resistance to 24-h blood pressure control

Aldosterone excess has been reported to be a common cause of resistant hypertension. To what degree this represents true treatment resistance is unknown.

Objective: The present study aimed to compare the 24-h ambulatory blood pressure monitoring (ABPM) levels in resistant hypertensive patients with or without hyperaldosteronism.

Two hundred and fifty-one patients with resistant hypertension were prospectively evaluated with an early-morning plasma renin activity (PRA), 24-h urinary aldosterone and sodium, and 24-h ABPM. Daytime, night-time, and 24-h blood pressure (BP) and nocturnal BP decline were determined. Hyperaldosteronism (H-Aldo) was defined as suppressed PRA (<1.0 ng/ml per h or <1.0 [mu]g/l per h) and elevated 24-h urinary aldosterone excretion (>= 12 [mu]g/24-h or >= 33.2 nmol/day) during ingestion of the patient's routine diet.

Results: In all patients, the mean office BP was 160.0 +/- 25.2/89.4 +/- 15.3 mmHg on an average of 4.2 medications. There was no difference in mean office BP between H-Aldo and normal aldosterone status (N-Aldo) patients. Daytime, night-time, and 24-h systolic and diastolic BP were significantly higher in H-Aldo compared to N-Aldo males. Daytime, night-time, and 24-h systolic BP were significantly higher in H-Aldo compared to N-Aldo females. Multivariate analysis indicated a significant interaction between age and aldosterone status such that the effects of aldosterone on ambulatory BP levels were more pronounced with increasing age.

Conclusions: In spite of similar office BP, ABPM levels were higher in resistant hypertensive patients with H-Aldo. These results suggest that high aldosterone levels impart increased cardiovascular risk not reflected by office BP measurements.

Journal of Hypertension. 25(10):2131-2137, October 2007.
Pimenta, Eduardo; Gaddam, Krishna K; Pratt-Ubunama, Monique N; Nishizaka, Mari K; Cofield, Stacey S; Oparil, Suzanne; Calhoun, David A