Characterization of a group of essential hypertensives with impaired regulation of aldosterone.

The pattern of aldosterone excretion during high sodium intake in 100 patients with essential hypertension allowed the differentiation of two groups: in the majority of patients (group A, n = 64) aldosterone excretion was suppressed below 6 μg/day similar to the normotensive control group. In a second group (group B, n = 36), aldosterone remained above the control range despite forced sodium loading. In group B, serum potassium was significantly lower than in patients of group A (3.81 ± 0.44 meq/1 vs. 4.26 ± 0.57 meq/1, p< 0.001). The blood pressure lowering effect of spironolactone (200 mg/d) was more pronounced among patients in group B. Plasma renin values tended to be lower in group B compared to patients with suppressed aldosterone. Infusion of Angiotensin II (0.1 - 2 μg/kg/min) led to a similar relative rise of plasma aldosterone levels in both groups despite higher baseline values in group B. The exact mechanism of the impaired regulation of aldosterone in a subgroup of patients with essential hype...