Racial differences in pressure, volume and renin interrelationships in essential hypertension.

Abstract

SUMMARYThe interrelationships of arterial pressure, plasma volume (PV), and plasma renin activity were studied in 152 consecutive male patients with uncomplicated essential hypertension. Of these, 22 (17 white and 5 black) subjects had normal plasma volumes and because of tbe small number were not included in the analysis of results. Tbe remaining 130 (35 black and 95 white) patients were classified as having either expanded or contracted plasma volume. A higher percentage of black (43%) than white (21%) subjects were volume expanded (PV > 19 ml/cm) and a lower percentage of blacks (57%) than whites (79%) were volume contracted (PV < 17 ml/cm). There was no significant difference in mean arterial pressure and plasma renin activity between tbe volume expanded and contracted black patients. In contrast, the white patients with contracted plasma volume had significantly higher arterial pressures (p < 0.05) and plasma renin activity (p < 0.001) than those with expanded plasma volume. More blacks than whites had low plasma reoin activity and did not manifest the inverse relationship of plasma renin activity to plasma volume as did the whites. These data conflnn and extend previous observations that the relationship between plasma volume and plasma renin activity (PRA) in the male patient with essential hypertension seems to differ between the black and white race. Efforts to explain tbe low PRA in black patients might be best directed toward those patients with suppressed PRA and with contracted intravascular volume. (Hypertension 1: 136-141, 1979) KEY WORDS • racial differences • essential hypertension • plasma volume plasma renin activity T HE incidence of essential hypertension is higher in the black than the white race, 1 and more blacks than whites have low renin hypertension. 85 The cause(s) for these racial differences are not clearly understood. Explanations offered for these differences include: the high-salt intake by blacks," 17 the higher incidence of plasma volume expansion in black subjects" and the attenuated response of renin release to various stimuli in blacks."' '•" Besides race, other investigators have

Current status of angiotensin receptor blockers for the treatment of cardiovascular diseases: focus on telmisartan

“…If a two-drug combination does not work, other drugs from a different class should be added until blood pressure reaches the expected goal. With respect to treatment of black hypertensive patients, who are, usually, resistant to monotherapy with ARBs or ACEIs because they are low renin hypertensives, 87 the addition of a diuretic to an ARB or ACEI, eliminates this difference and black patients respond to these regimens similarly to whites. 88 Hypertensive patients with type II diabetes mellitus and diabetic nephropathy should preferably be treated with ARBs according to the recommendations of the American Diabetes Association.…”

Hemodynamic differences between black patients and white patients with essential hypertension. State of the art lecture.

“…For the purposes of that study, 14 plasma volume exceeding 19.0 ml/cm was considered arbitrarily to be "expanded" plasma volume, and any level of plasma volume less than 17.0 ml/cm was considered arbitrarily to be "contracted" plasma volume. There were 22 patients (17 white and 5 black) whose plasma volume was found to be normal (i.e., 18.0±0.9 ml/cm), and because of the small number in this group, they were excluded from the analysis.…”

“…Hence, there is a segment of black patients with essential hypertension in whom arterial pressure, intravascular volume, and plasma renin activity do not demonstrate the normal interrelations among these three variables that were found in white patients, and these black patients seemed to be more volume dependent for any level of arterial pressure (Table 2). 14 …”

Blood Pressure Effects of High-Dose Amlodipine-Benazepril Combination in Black and White Hypertensive Patients Not Controlled on Monotherapy

“…[21] However, certain populations, like AfricanAmericans, are resistant to drugs that block the renin-angiotensin-aldosterone system [RAAS], like ACE inhibitors and ARBs given as monotherapy, [22,23] because these drugs exert their major antihypertensive effects through the blockade of RAAS, and Black patients are usually low-renin and volume-dependent hypertensive subjects. [24] Several clinical trials have shown that the combination of ACE inhibitors with CCBs increases their hypotensive potency [11][12][13][14][15][16][17]25] because of a synergistic effect of inhibition of RAAS and a direct arterial dilatory effect, which is independent of RAAS inhibition. Most of the previous publications have used lower-dose ACE inhibitor-CCB combinations and did not specifically focus on the antihypertensive effects of these drug combinations on Black hypertensive patients compared with their White counterparts.…”