Blood pressure and metabolic responses to hydrochlorothiazide, captopril, and the combination in black and white mild-to-moderate hypertensive patients.

Mild-to-moderate essential hypertensive patients (255) were assigned to receive hydrochlorothiazide 15 mg three times a day, captopril 25 mg three times a day, or both. A significant decline in blood pressure was seen in 84% of patients taking both agents, while 43% of those taking captopril and 64% of those taking hydrochlorothiazide showed a significant blood pressure response. Among white hypertensives receiving captopril alone, a normalization of blood pressure occurred in 46% and a significant reduction in 8% was observed which was significantly (p less than 0.05) higher than that observed in black subjects where only 31% showed a normalization of their pressure with captopril alone. With hydrochlorothiazide, 53% of blacks and 54% of whites showed normalization of their pressures. With the combination, over 80% of the patients in both racial groups demonstrated a normalization or significant reduction in blood pressure. With hydrochlorothiazide alone, significant (p less than 0.05) decreases in serum potassium, increases in uric acid, blood glucose, and blood cholesterol were seen. With captopril alone, no changes in any of these measurements were observed. When captopril was added to hydrochlorothiazide, a significant attenuation of the diuretic effect on potassium and uric acid was observed, and the significant change in blood sugar and cholesterol seen with the diuretic alone was prevented. These observations suggest that there are heterogeneous responses to hypertensive monotherapy based on race. Furthermore, it suggests that when a single therapeutic agent is not adequate in controlling blood pressure to the desired levels, the addition of either hydrochlorothiazide or captopril should produce a further reduction in blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)