Malignant Hypertension: Effect of Therapy on Renin and Aldosterone

Plasma renin activity (PRA) and aldosterone secretion rate (ASR) were measured in 22 patients in balance on a 100 mEq sodium diet during the malignant phase of hypertension and at intervals during long-term follow-up on pharmacological therapy. Three patients had normal PRA and ASR during malignant hypertension. Eighty-six per cent of patients had an increased ASR, but only in 36% was PRA concomitantly increased during malignant hypertension (one patient developed elevated PRA in the postmalignant period). PRA fell to normal in 87% of patients after antihypertensive therapy. ASR fell to normal on drug therapy in six patients, and in all of these there was a period during the postmalignant phase in which ASR was increased while PRA was normal or suppressed. In addition to this group with reversible hyperaldosteronism, all but two of the remaining patients with elevated ASR had periods during which ASR was increased at the same time that PRA was normal or suppressed. These data raise the possibility that either a nonrenin aldosterone-stimulating hormone is secreted in malignant hypertension or that excessive stimulation of the adrenal by angiotensin can lead to persistent hyperfunction of aldosterone-secreting cells with a quantitatively deranged feedback control. One patient had an aldosterone-secreting adenoma and had manifestations of the hyperaldosteronism antedating the development of malignant hypertension.