Age- and sex-related differences in plasma aldosterone in essential hypertension. Relationship to plasma renin activity.

In essential hypertension mean basal (supine) and stimulated plasma renin activity (2 h upright posture + 40 mg furosemide intraveneously) decreased progressively with age. No significant differences were observed in renin levels between male and female patients. With increasing age mean basal (supine) plasma aldosterone remained almost unchanged in females, whereas in males a slight increase was found. However, in the comparable age-groups no significant sex-related differences were obtained. In female patients changes in mean stimulated plasma aldosterone with increasing age paralleled those of plasma renin activity, whereas in males this relationship was less obvious: only a slight age-related decline in stimulated aldosterone levels was observed and significantly lower plasma aldosterone concentrations in male than in female hypertensives of the younger age-groups (less than 40 years) were found. The results indicate that in essential hypertension with increasing age dissociation between plasma aldosterone and plasma renin activity occurred. Furthermore, the described alterations in adrenal aldosterone release are more pronounced in male than in female patients.