Indicators of mineralocorticoid excess in the evaluation of primary aldosteronism

Abstract

It is suggested to use the aldosterone-to-renin ratio (ARR) as a first test in the screening for primary aldosteronism (PA). However, many groups rather rely on the determination of urinary tetrahydroaldosterone secretion; others calculate a ratio of urinary aldosterone to plasma renin activity. The aim of the present study was to evaluate the usefulness of different parameters of aldosterone excess in the case finding of PA. The study included 28 patients with PA and 33 subjects with essential hypertension. Clinical data, which included the hormonal parameters, serum aldosterone, plasma renin concentration, urinary free aldosterone and metabolites and serum and urinary electrolyte levels were analyzed. These indices of aldosterone excess, the ARR, serum sodium to urinary sodium to (serum potassium) 2 to urinary potassium (SUSPPUP) ratio and combinations of these parameters were compared between the groups. Receiver-operating curve analysis revealed that the ARR multiplied by the SUSPPUP ratio (ARRÂSUSPPUP) is the most reliable screening test, with a sensitivity of 92.3% and a specificity of 93.9% (cutoff point 199.2 (mmol l À1 ) À1 ). The combination of ARRÂSUSPPUP ratio with urinary free aldosterone divided by the plasma renin concentration rendered a specificity of 100%. Less useful was the correction of urinary free aldosterone and its metabolites for sodium excretion. Although the ARR and urinary free aldosterone divided by renin are good tests in the screening for PA, the combination of ARR with SUSPPUP ratio is a better indicator of an aldosterone excess and aldosterone action in patients with ongoing antihypertensive medication. Antihypertensive drugs only marginally interfere with the SUSPPUP ratio, but they may influence the ARR, whereby the effects in PA patients seem to be negligible.

Aldosterone- and cortisol-co-secreting adrenal tumors: the lost subtype of primary aldosteronism

“…More than two-thirds of reported patients were female subjects, although preference of female sex in patients with PA is not a consistent observation (59)(60)(61).…”

Construction of a predictive scoring system as a guide to screening and confirmation of the diagnosis of primary aldosteronism

“…Serum sodium has previously been utilized as an indicator for mineralocorticoid excess by incorporating it into 'the serum sodium to urinary sodium to (serum potassium) 2 to urinary potassium (SUSPPUP) ratio'. 28,29 Thus, the higher serum the sodium and the lower the serum potassium, the higher the SUSPPUP ratio and the probability of PA. However, SUSPPUP ratio required urinary collection which was relatively inconvenient in clinical practice; our scoring system, therefore, provides a more pragmatic approach.…”

Assessment of serum sodium to urinary sodium divided by (serum potassium)² to urinary potassium as a screening tool for primary aldosteronism

“…The SUSPPUP performed worse in our population than in the original study where the area under the ROC curve was 0·90 [11], or than in the subsequent study where the area under the ROC curve was 0·87 [12]. Several differences in protocol and in population between the original study and ours must be outlined.…”

“…However, the fact that Balas et al. [12], who also used 24‐h urine, found a diagnostic value close to the original study argues against this hypothesis.…”

“…The original study found an area under the receiving operator characteristic (ROC) curve of 0·90 to detect PA; the sensitivity was 89% and specificity 86% for a SUSPPUP ratio over 5·3 L mmol −1 [11]. These results were supported by a second small study, where the area under the ROC curve was 0·87, the sensitivity was 85% and the specificity 82% for a SUSPPUP ratio over 5·95 L mmol −1 [12]. We undertook a retrospective study to validate this ratio in a large sample of patients with PA or essential hypertension (EH).…”