ECE2020 Audio ePoster Presentations Adrenal and Cardiovascular Endocrinology (121 abstracts)
Objective: The saline infusion test (SIT) is a standard confirmatory test for primary aldosteronism (PA) and based on impaired aldosterone suppression in PA compared to essential hypertension (EH). In the past, aldosterone was quantified using immunoassays (IA). Due to the more widespread use of liquid chromatography tandem mass spectrometry (LC-MS/MS) in clinical routine, we aimed at a method-specific aldosterone threshold for the diagnosis of PA during SIT and explored the diagnostic utility of other mineralocorticoids and glucocorticoids.
Design: Cohort study of 187 paired SIT samples at a single tertiary endocrine center 2009–2018. Diagnosis of PA (n = 103) and EH (n = 84) was established based on clinical routine workup without taking LC-MS/MS values into account.
Methods: LC-MS/MS using a commercial steroid panel with a lower limit of quantification for aldosterone of 10 ng/l. Receiver operator characteristics analysis was used to determine method-specific cut-offs.
Results: Aldosterone measured by IA was on average 31 ng/l higher than with LC-MS/MS. Cut-offs were comparable with 64 ng/l for IA (sensitivity: 93%, specificity: 90%, area under the curve (AUC) 0.955) and 69 ng/l for LC-MS/MS (80%, 89%, 0.902). Other steroids did not provide additional diagnostic value.
Conclusions: Quantification of aldosterone with LC-MS/MS and IA yields in comparable SIT-cut-offs for PA. Lower AUC for LC-MS/MS is likely due to the large spectrum of disease in PA and previous decision making based on IA results. Until data of a prospective trial with clinical endpoints are available, the suggested cut-off can be used in clinical routine.
05 Sep 2020 - 09 Sep 2020