Renin-angiotensin-aldosterone system in arterial hypertension

Plasma renin activity (PRA), plasma aldosterone concentration (PAC), and urinary aldosterone (UA) were compared in 311 hospitalized patients with arterial hypertension and in 54 healthy subjects. Patients with fixed benign essential hypertension (EH) had PRA, both recumbent and upright, the same as the controls; in advanced EH, increased PRA was accompanied by higher blood pressure (BP) as well. Nevertheless no direct correlation was found between the individual values of mean BP and PRA. The group of EH with suppressed PRA (35.9%) had a higher men age and included a higher percentage of women. Suppressed PRA was proved also in 20.9% of patients with renal hypertension and in 34.4% of patients with hypertension in chronic renal insufficiency. The PAC was moderately higher in benign EH than in the controls, and so was the urinary excretion of 18-aldosterone glucuronide (UA). Markedly elevated PAC was found in groups with high PRA. In primary aldosteronism, high UA and PAC together with suppressed PRA represent an important diagnostic guideline for differentiation from other types of low-renin hypertensions. The study points out a great variance of PRA, PAC, and UA values in different types of hypertension, and analyses the significance of their changes for the pathogenesis, course, and diagnosis of arterial hypertensions.