Blood Pressure in Relation to the Renin—Angiotensin—Aldosterone System

Abstract

ABSTRACT. The relationship between blood pressure (BP) and the renin—angiotensin—aldosterone system was studied in a stratified random sample (n = 120) of 49‐year‐old men selected from a BP screening and covering a wide range of BPs. Only subjects not on antihypertensive treatment were included. None had malignant or secondary hypertension. Plasma renin activity, plasma concentrations of angiotensin II, aldosterone, sodium, potassium and noradrenaline and the 24‐hour urinary excretions of sodium, cortisol and noradrenaline were determined. Of these variables, only p‐aldosterone was significantly correlated with BP, both in the whole study group (R=0.22, p<0.02, n = 119) and in the subjects with the highest BP range (R =0.36, p<0.02, n=30). Of the clinical groups compared, the hypertensive subjects had significantly higher mean p‐aldosterone than the borderline and normo‐tensive subjects. Multiple regression analysis showed that the 24‐hour urinary excretion of noradrenaline was the factor most strongly correlated to p‐aldosterone, suggesting that the sympathetic nervous system might stimulate aldosterone secretion. Our findings indicate that aldosterone may be of importance for the development and maintenance of essential hypertension.

Aldosterone-to-renin ratio and home blood pressure in subjects with higher and lower sodium intake: the Ohasama Study

“…Many studies [1][2][3][4][5] have indicated a positive association between aldosterone and hypertension; others [6][7][8] have shown that hypertensive patients had normal 6,8 or low 7 aldosterone levels compared with values in normotensive subjects. One of the reasons for these inconsistent results could be the confounding effect of antihypertensive medications, differences in time of blood sampling, body position and dietary sodium intake, which significantly affect aldosterone levels.…”

“…9,10 In most studies, longterm dietary sodium intake has not been considered. Most studies 1,[3][4][5][6][7][8] use spot urine samples, 1,7,8 24-h urine collection 4,6 and short-term dietary sodium restriction; 5,6 only one study 3 measured long-term habitual sodium intake using a dietary record. To evaluate the longterm effect of dietary sodium intake, we surveyed habitual dietary sodium intake.…”

“…All the above-mentioned studies [1][2][3][4][5][6][7][8] were based solely on conventional blood pressure (CBP) measurements. No studies have investigated the association between ARR and hypertension using home blood pressure (HBP) measurements, which are reportedly more reliable than CBP and avoid both observer and regression dilution biases.…”

Inhibition of the renin–angiotensin–aldosterone system

“…Notably, aldosterone is also implicated in arterial and tissue remodelling and injury, especially under conditions of high salt intake, in addition to its classic effects on renal sodium reabsorption and potassium excretion [10]. Elevation in BP levels, as well as cardiovascular and renal damage, can occur as consequences of the integrated multiple functions of this highly regulated and complex system [11]. In fact, by acting with blockers of the RAAS, at appropriate doses and with various combinations, BP can be controlled from the very high values encountered in some circumstances, such as primary or secondary malignant hypertension up to the induction of orthostatic hypotension, severe dehydration and functional renal insufficiency.…”