The effect of age, sex and BMI on the aldosterone-to-renin ratio in essential hypertensive individuals

Abstract

The aldosterone-to-renin ratio (ARR) is widely used as a screening test for primary aldosteronism, but its determinants in patients with essential hypertension are not fully known. The purpose of the present investigation is to identify the impact of age, sex and BMI on renin, aldosterone and the ARR when measured under strict, standardized conditions in hypertensive patients without primary aldosteronism.Methods: We analysed the data of 423 consecutive hypertensive patients with no concomitant cardiac or renal disorders from two different hospitals (Rotterdam and Maastricht) who had been referred for evaluation of their hypertension. Those who were diagnosed with secondary causes of hypertension, including primary aldosteronism, were excluded from analysis. Patients who used oral contraceptives or had hormonal replacement therapy were excluded as well. Plasma aldosterone concentration (PAC), active plasma renin concentration (APRC) and the ARR were measured under standardized conditions. All measurements were taken in the supine position at 10.00 h in the morning, with one subgroup of patients adhering to a sodium-restricted diet (55 mmol/day) for no less than 3 weeks, and the other subgroup maintaining an ad libitum diet. In those who were receiving antihypertensive treatment, all medications were discontinued at least 3 weeks before testing.Results: In neither group did aldosterone correlate with age. Renin, however, was inversely related to age both during low-salt diet (P < 0.001) and during ad lib salt intake (P ¼ 0.05). This resulted in a significant positive correlation between age and the ARR in both groups. Although on both dietary regimens, PAC and APRC were significantly higher in men when compared with women, the ARR was not significantly different between the two sexes. The age-relationships of renin and the ARR were comparable in men and women on both diets, albeit with greater variability in women. There was an upward trend between BMI and the ARR, which reached statistical significance only in men on low-salt diet. In multivariable regression analysis, age remained the only independent determinant of the ARR. Conclusion:In our essential hypertensive population, the ARR increased significantly with age but was not affected by sex or BMI.

Prevalence and Characteristics of Low-renin Hypertension in a Primary Care Population

“…Patients with low-renin hypertension were on average 5 years older than those with normal renin hypertension. An inverse relationship between age and renin has been previously reported in many studies [ 39 , 40 ]. Yin et al measured plasma renin activity in 274 patients with essential hypertension; the median plasma renin activity for 20 to 29-year-olds was 5.6 ng/mL/hour compared to 2.3 ng/mL/hour in those aged 60 years or older [ 39 ].…”

Reply to ‘Could we be missing something when calculating the aldosterone-to-renin ratio?’

“…We thank Dr Karadeniz and colleagues for their comments [1], regarding our article on the effect of age, sex, and BMI on the aldosterone-to-renin ratio in hypertensive individuals [2]. We entirely agree that loop diuretics and spironolactone may have a long-lasting effect on the renin–angiotensin–aldosterone system.…”

Could we be missing something when calculating the aldosterone-to-renin ratio?

“…We read with great interest the article published in the Journal of Hypertension , entitled ‘The effect of age, sex and BMI on the aldosterone-to-renin ratio in essential hypertensive individuals’ by Alnazer et al [1]. We would like to provide some comments on the issue.…”