False-Negative Rate High for Seated Saline Suppression Test for Primary Aldosteronism

THURSDAY, May 8, 2025 (HealthDay News) — The four-hour seated saline suppression test (SSST) is associated with a high false-negative rate for diagnosing primary aldosteronism (PA), according to a study published online May 6 in the Annals of Internal Medicine.

Alexander A. Leung, M.D., M.P.H., from the University of Calgary in Alberta, Canada, and colleagues conducted a diagnostic test accuracy study involving 156 adults with a positive screening result for PA to perform a blinded assessment of the SSST. The SSST was performed by administering 2 L of 0.9 percent sodium chloride intravenously over four hours while the patient was seated. The reference standard for determining disease status was treatment response.

The researchers found that treatment responders and nonresponders had an overlap in post-SSST aldosterone concentrations measured using immunoassay (median, 329 pmol/L [interquartile range, 227 to 525 pmol/L] versus median, 255 pmol/L [interquartile range, 162 to 346 pmol/L]). The SSST did not discriminate between response statuses (area under the curve, 62.1 percent). For aldosterone cutoffs ranging from 140 to 300 pmol/L, the positive and negative likelihood ratios were equivocal. After differences in treatment, occurrence of hypokalemia, and laboratory assay used were accounted for, these findings remained consistent.

“The results of our study suggest that removal of routine confirmatory testing from the diagnostic care pathway for PA may help to improve diagnostic accuracy and reduce the time needed for diagnosis and treatment for most patients,” the authors write.

Several authors disclosed ties to relevant organizations.

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