Hypertension and age: clinical and biochemical correlates.

Plasma renin activity, aldosterone and norepinephrine levels were determined in 247 ambulatory hypertensive patients divided into young, middle aged, and old groups. PRA and the increase of PRA after furosemide were higher in the younger; NE was higher in the old group. Some relationships may be inherent in aging and not necessarily confined to hypertensives. This may explain discrepancies between reports by investigators who studied homogenous groups classified in different ways.