Comparison of long-term hemodynamic effects at rest and during exercise of lisinopril plus sodium restriction versus hydrochlorothiazide in essential hypertension.

To investigate whether sodium restriction might replace thiazides in promoting blood pressure (BP) reduction by angiotensin-converting enzyme inhibitors, the long-term hemodynamic effect of lisinopril plus sodium restriction versus lisinopril plus hydrochlorothiazide was compared at rest and during dynamic exercise in 2 groups of essential hypertensive patients. Mean pretreatment intraarterial BP at rest sitting was 177/107 mm Hg. The patients were randomly allocated to lisinopril combined with either low salt diet (low salt group, n = 13) or hydrochlorothiazide (diuretic group, n = 12). After 1 year of treatment the mean dose of lisinopril was 25 mg in both groups. In the low salt group sodium excretion was reduced from 188 to 129 mmol/24 hours (p less than 0.01). In the diuretic group sodium excretion was unchanged with a mean dose of hydrochlorothiazide of 19 mg. BP was reduced (p less than 0.001) in both groups: at rest 16 and 21% and during exercise 10 and 13% in the low salt and the diuretic groups, respectively. Total peripheral resistance was reduced (p less than 0.05) in both groups: at rest 14 and 7% and during exercise 8 and 5% in the low salt and the diuretic groups, respectively. Overall cardiac output was reduced (p less than 0.05) in the diuretic group but remained unchanged in the low salt group. Thus, lisinopril--either in combination with a diuretic or sodium restriction--induces marked reduction in BP due to decreases in peripheral vascular resistance both at rest and during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)