Ontology highlight
ABSTRACT: Context
Clinicians frequently rely on aldosterone thresholds derived from older immunoassays to diagnose primary aldosteronism. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is increasingly widespread and reported to yield lower aldosterone concentrations.Objective
Given the health impact of incorrect interpretations of aldosterone levels, we compared measurements using LC-MS/MS and immunoassay across the full range of aldosterone physiology by evaluating distinct regulation by angiotensin II and adrenocorticotropin (ACTH).Methods
Normotensive volunteers underwent prospective characterization of aldosterone production by immunoassay and LC-MS/MS during 4 conditions (n = 188): oral sodium suppression and restriction (to assess angiotensin II-mediated aldosterone production) and dexamethasone suppression and cosyntropin stimulation (to assess ACTH-mediated aldosterone production).Results
Serum aldosterone concentrations by LC-MS/MS and immunoassay had a correlation of 0.69 (P < .001), with good agreement (intraclass correlation 0.76; 95% CI 0.52-0.87). Aldosterone was lower by LC-MS/MS than immunoassay (median 10.5 [3.8, 21.9] vs 19.6 [9.5, 28.0] ng/dL; P < .001), with an average difference of 37.2%. The most notable discrepancy was in the clinically discriminatory range <20 ng/dL: 9.9 (7.1, 13.8) ng/dL using immunoassay corresponded to 5.5 (1.4, 8.9) ng/dL by LC-MS/MS (P < .001). Following oral sodium suppression, the aldosterone-to-renin ratio was 4-fold higher using immunoassay (27.2 [19.7, 62.4] vs 6.4 [3.5, 19.1] ng/dL per ng/mL/hour; P < .001).Conclusion
Aldosterone measurements are substantially lower by LC-MS/MS than immunoassay across the full physiologic range, especially when aldosterone levels were less than 20 ng/dL. These findings highlight the need to recalibrate diagnostic interpretations when measuring aldosterone via LC-MS/MS and provide insights into potential biologic causes of assay differences.
SUBMITTER: Brown JM
PROVIDER: S-EPMC9032635 | biostudies-literature | 2022 Jun
REPOSITORIES: biostudies-literature
Journal of the Endocrine Society 20220323 6
<h4>Context</h4>Clinicians frequently rely on aldosterone thresholds derived from older immunoassays to diagnose primary aldosteronism. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is increasingly widespread and reported to yield lower aldosterone concentrations.<h4>Objective</h4>Given the health impact of incorrect interpretations of aldosterone levels, we compared measurements using LC-MS/MS and immunoassay across the full range of aldosterone physiology by evaluating distinct reg ...[more]