Relationships between blood pressure and plasma renin, aldosterone and dopamine-beta--hydroxylase in the elderly. Studies in patients over 70 years of age.

Plasma renin activity (PRA), aldosterone (PA) and dopamine-beta-hydroxylase activity (DBH) were measured in 49 subjects over 70 years of age, selected for normal or high blood pressure level. By comparison with younger controls, elderly subjects exhibited lower supine or upright PRA, but similar PA and DBH. No relationship could be found between individual blood pressure, and PRA, PA or DBH. The data favor the view that the renin-angiotensin-aldosterone system does not play an important causative role in elderly hypertension. They also point to the necessity of age-matched controls when this system is being studied in elderly patients.