Diagnosis of primary aldosteronism (PA) is made by screening, confirmation testing and subtype diagnosis (CT scan and adrenal vein sampling, AVS). However, some tests are costly and unavailable in most hospitals. We evaluated the role of serum 18-hydroxycorticosterone (s18OHB) and urinary and serum 18-hydroxycortisol (u and s18OHF) and 18-oxocortisol (u and s18oxoF) in the diagnosis of PA and its subtypes, aldosterone-producing adenoma (APA) and bilateral adrenal hyperplasia (BAH). We studied 62 patients with low-renin essential hypertension (EH), 81 PA (20 APA, 61 BAH), 24 patients with glucocorticoid-remediable aldosteronism, 16 patients with adrenal incidentaloma and 30 normotensives. We measured s18OHB, s18OHF and s18oxoF before and after saline load (SLT) and 24hour u18OHF and u18oxoF. PA patients displayed significantly higher levels of s18OHB, u18OHF and u18oxoF compared to EH and normals; APA patients displayed s18OHB, u18OHF and u18oxoF levels significantly higher than BAH patients. Similar results were obtained for s18OHF and s18oxoF. SLT significantly reduced s18OHB, s18OHF and s18oxoF in all groups but steroid reduction was much less for APA patients compared to BAH and EH. The s18OHB/aldosterone ratio after SLT more than doubled in EH, but remained unchanged in APA patients. In conclusions: u18OHF, u18oxoF and s18OHB measurements in patients with a positive ARR correlate with confirmatory tests and AVS in PA patients. If verified, these steroid assays would refine the diagnostic work-up for PA.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.