THE EFFECT OF AGE, BMI, AND SEX ON ALDOSTERONE, RENIN AND THE ALDOSTERONE-TO-RENIN RATIO IN ESSENTIAL HYPERTENSIVES

Abstract

Abstract Objective: The aldosterone-to-renin ratio (ARR) is widely used as a screening test for primary aldosteronism (PA) in patients with hypertension. The purpose of the present investigation is to identify the impact of age, body mass index (BMI) and sex on renin, aldosterone, and the ARR, when measured under strictly standardised conditions. Design and method: We measured plasma aldosterone, plasma renin concentration and the ARR in 190 essential hypertensive patients (120 males, 70 females). All measurements were taken in the supine position at 9am. A low sodium diet (55mmol/day) was in place for no less than two weeks prior to screening. In those who were receiving antihypertensive medications, all medications were discontinued at least 2 week before testing. Results: Renin and aldosterone were significantly higher in men, and remained so when controlling for BMI and age. However, the ARR was not significantly affected by sex. Aldosterone was not significantly influenced by age but renin correlated inversely with age, with and without controlling for BMI (r = -0.285, p < 0.001). The ARR was positively correlated with age (r = 0.236, p < 0.001), with and without controlling for BMI. Subgroup analysis demonstrated a significant effect on the ARR in males only, with and without controlling for BMI (p < 0.001 and p0.004, respectively). Although renin and aldosterone individually were not significantly influenced by BMI, the ARR showed a positive correlation (p = 0.022). However, this effect was not seen when age was controlled for nor was it seen in the subgroup analysis of males and females (p = 0.125, p = 0.515, p = 0.207, respectively) Conclusions: Under strictly standardized conditions, advanced age is associated with an increased ARR in male essential hypertensives. BMI when controlling for age does not influence the ARR. The impact of sex on the ARR appears negligible.