Diagnosis under Random Conditions of All Disorders of the Renin-Angiotensin-Aldosterone Axis, Including Primary Hyperaldosteronism

Abstract

Theoretically, the relationship between plasma aldosterone (PA) and PRA in normal subjects under random conditions should differ from that in patients with primary hyperaldosteronism or primary adrenal failure, but should be similar to that in patients with secondary hyperaldosteronism or hyporeninemic hypoaldosteronism. PA, expressed as a function of PRA, the PA/PRA ratio, provides an index of adrenal sensitivity in normal subjects under routine conditions. The random PA/PRA ratios in patients with primary adrenal disorders did not overlap with those in normal subjects, patients with secondary adrenal disorders, hypertensive subjects, or other patients. A single elevated PA/PRA ratio, i.e. more than 920, associated with elevated PA in 4 patients or normal PA in 6 patients indicated primary hyperaldosteronism in 10 patients. However, 5 of 17 patients with chronic renal failure had elevated PA/PRA ratios, but did not have primary hyperaldosteronism. All 14 patients with secondary hyperaldosteronism had elevated PA associated with normal PA/PRA ratios. A single PA/PRA ratio of less than 28 associated with low PA in 18 patients and a normal PA in 1 patient indicated primary adrenal insufficiency, while a low PA associated with a normal PA/PRA ratio indicated hyporeninemic hypoaldosteronism in 7 patients. Fifty-nine patients with nonadrenal disorders other than renal failure had normal PA and PA/PRA ratios. Therefore, with the exception of patients with advanced renal failure, only a single blood sample is required to establish all diagnoses of disorders of the renin-angiotensin-aldosterone axis under random conditions.

Confirmatory testing in normokalaemic primary aldosteronism: the value of the saline infusion test and urinary aldosterone metabolites

“…The aldosterone/renin ratio is currently the most recommended screening test for primary aldosteronism (3,(6)(7)(8)(9)(10). Application of the ratio even under antihypertensive medication is increasingly advocated (8,11,12).…”

Comparison of active renin concentration and plasma renin activity for the diagnosis of primary hyperaldosteronism in patients with an adrenal mass

“…In contrast to single measurement of either PAC or PRA, the PAC to PRA ratio seems to be independent of diurnal and day-to-day variations, salt intake and diuretics. It was demonstrated as a reliable and convenient screening tool for ambulatory conditions, independent of body posture (6). However, a recent study revealed a low reproducibility of the ratio in patients with an aldosterone-producing adrenal adenoma under random conditions (7).…”

Aldosterone to renin ratio as a determinant of exercise blood pressure response in hypertensive patients

“…More recently, the aldosterone to renin ratio (ARR) has emerged as an index of 'inappropriate aldosterone activity' for which blood sampling could be easily done in the out-patient department, but has inherently better reproducibility in dissecting out the various aetiological contributions to hypertension. 2 This index relates to plasma sodium (directly) and potassium (inversely) in essential hypertension, 3 the two consistent and basic electrolyte features of this disease. 4 This inappropriate aldosterone activity in hypertension may also have a genetic basis, relating to aldosterone synthase (CYP11B2) genetic polymorphism.…”