[Renin-angiotensin-aldosterone system in essential hypertension. Inappropriately high plasma aldosterone in young patients with severe hypertension and in older hypertensives].

Both in male (n = 353) and in female patients (n = 211) with essential hypertension supine (basal) plasma renin activity showed an age-dependent significant decrease whereas plasma aldosterone remained almost unchanged in women or was even slightly increased with age in men. In younger hypertensives (15-34 years) a significant inverse correlation between plasma renin activity and mean arterial blood pressure could be observed. On the other hand, middle-aged men (35-50 years) showed a positive relationship between renin and blood pressure whereas in females of the same age group no correlation between these two parameters was found. In older patients (greater than 50 years) of both sexes a positive correlation between renin activity and mean arterial blood pressure was obtained. In all age-groups and in both sexes there was either no correlation, or only a weak (positive) one, between plasma aldosterone and mean arterial blood pressure. These findings suggest that in essential hypertension renin secretion is regulated mainly by blood pressure. The observed sex and age-related differences may be due to changes in the renovascular system. The inappropriately high plasma aldosterone concentrations (compared to the relatively low renin levels) in younger hypertensives with severe hypertension, and in the older population, document disturbed aldosterone secretion which probably contributes to the elevated blood pressure in these patients.