Postural test to differentiate primary aldosteronism from low-renin hypertension: a retrospective single-center study

TL;DR

A postural test helps distinguish primary aldosteronism from low-renin hypertension by analyzing renin levels and other factors.

Contribution

The study introduces the postural stimulation test as a novel method to differentiate primary aldosteronism from low-renin hypertension.

Findings

96% of primary aldosteronism cases were detected when renin levels remained suppressed during the postural test.

Renin response during the postural test and hypokalemia are key parameters for distinguishing primary aldosteronism from low-renin hypertension.

Cluster analysis identified distinct patterns of renin suppression and potassium levels between primary aldosteronism and low-renin hypertension patients.

Abstract

The diagnostic accuracy of screening and confirmatory tests to differentiate primary aldosteronism (PA) among patients with low-renin hypertension (HTN) is suboptimal. We aimed to assess the role of the postural stimulation test (PST) in differentiating PA from low-renin HTN.

Clinical and endocrine data in clinostatic position (CP) and orthostatic position (OP) during PST were evaluated in 190 hypertensive patients: 80 with PA and 110 with low-renin HTN. Multivariate techniques were computed: Principal Component Analysis (PCA), Partial Least Square-Discriminant Analysis (PLS-DA) and k-means clustering.

PST response differentiated our cohort: 96% of PA were detected in the 56/190 patients with always suppressed renin levels during PST, 80% of patients with low-renin HTN were identified among 56/190 subjects with de-suppression of renin from CP to OP and 78/190 with always measurable renin. Normal potassium and measurable renin in OP were predictors of low-renin HTN. Cluster analysis distinguished PA from low-renin HTN: Cluster 2 included 104/110 low-renin HTN; Cluster 1 PA patients showed a higher frequency of suppressed renin levels at baseline and during PST (100% in CP and 95% in OP, respectively). Cluster 1 low- renin HTN patients had lower potassium and a higher frequency of suppressed renin levels at diagnosis and during PST, compared to Cluster 2. PLS-DA and PCA confirmed that renin in OP, renin response to PST, and hypokalemia were the most relevant parameters for distinguishing PA from low-renin HTN.

Renin response during PST can be used to differentiate PA from low-renin HTN.

The online version contains supplementary material available at 10.1007/s40618-025-02752-9.

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