Plasma renin activity, aldosterone and cortisol levels during physical exercise in essential hypertension.

Plasma renin activity, aldosterone and cortisol levels, as well as renal blood flow were studied in borderline and established hypertensive patients and in healthy control subjects at rest and following graded dynamic upright exercise. Resting plasma renin activity was elevated in established hypertension, renal blood flow at rest was decreased in patients with borderline hypertension but its per cent decrease during exercise was similar in all groups. Following exercise, plasma renin activity increased in all groups but a step-wise increase with graded exercise occurred only in borderline hypertension. Resting plasma aldosterone and cortisol levels were similar in all groups. In the hypertension patients physical exercise was associated with disproportional changes of plasma renin activity and aldosterone levels. Plasma cortisol displayed patterns which were roughly similar to those or aldosterone in the control group an in established hypertension, but not in the borderline group, where the most pronounced increased of aldosterone level was associated with the lowest level of cortisol. It is concluded that the physiological response of the renin-angiotensin-aldosterone system to physical exercise is altered in essential hypertension.