Ann Intern Med

Seated saline suppression test in primary aldosteronism doesn’t stand up to scrutiny

May 7, 2025

Study details: This diagnostic test accuracy study, conducted at the regional Endocrine Hypertension Clinic in Calgary, assessed the seated saline suppression test (SSST) for primary aldosteronism (PA). The study involved 156 adults with positive screening results for PA. Participants received 2 liters of 0.9% sodium chloride intravenously over 4 hours while seated. The reference standard for determining disease status was based on treatment response, including BP reduction, decreased antihypertensive medication, and normalization of biochemical markers.

Results: Post-SSST aldosterone concentrations measured via immunoassay showed significant overlap between treatment responders and nonresponders (329 pmol/L vs. 255 pmol/L). The SSST failed to distinguish between response statuses, with an area under the curve of 62.1% (95% confidence interval [CI], 45.1% - 79.1%). Positive and negative likelihood ratios were inconclusive for aldosterone cutoffs ranging from 140 to 300 pmol/L. These results persisted despite accounting for treatment differences, hypokalemia, and laboratory assay variations.

Clinical impact: The SSST's high false-negative rate suggests that reliance on this test may result in missed opportunities for intervention in patients with PA. Use caution when interpreting SSST results for diagnosis and consider alternative methods to ensure accurate detection and appropriate treatment of PA.

Source:

Leung AA, et al. (2025, May 6). Ann Intern Med. Confirmatory Testing for Primary Aldosteronism : A Study of Diagnostic Test Accuracy. https://pubmed.ncbi.nlm.nih.gov/40324193/