Renin Dependency of Blood Pressure in Isolated Systolic Hypertension

Abstract

The role of the renin system in the maintenance of the elevated systolic blood pressure in isolated systolic hypertension was investigated in 31 patients who received long-term treatment with propranolol (120 mg daily) and in another group of 22 patients with isolated systolic hypertension who received a test dose of captopril (25 or 50 mg). The greatest systolic blood pressure decrease (35 +/- 5 mm Hg) by propranolol occurred in the high-renin group (n = 9), and the smallest decrease (3 +/- 2 mm Hg) in the low-renin group (n = 9), whereas in the normal-renin group (n = 13), systolic blood pressure was decreased by propranolol by 22 +/- 5 mm Hg. For all the propranolol-treated patients, the decrement in the systolic blood pressure by propranolol was related to the control plasma renin activity (r = 0.63, p less than 0.01) and to the concurrent change in plasma renin activity (r = 0.70, p less than 0.001). Captopril decreased the systolic blood pressure by 55 +/- 10 mm Hg in the high-renin group (n = 11) and by 17 +/- 5 mm Hg in the normal-renin group (n = 6), whereas the smallest decrease (12 +/- 5 mm Hg) in systolic blood pressure occurred in the low-renin group (n = 5). In all the captopril-tested patients (n = 22), the decrease in systolic blood pressure by captopril was related to the control plasma renin activity (r = 0.75, p less than 0.001). These results indicate that the plasma renin activity value indicates the participation of the renin-angiotensin system in the maintenance of the elevated systolic blood pressure in patients with isolated systolic hypertension.