This prospective observational study evaluates a simplified biochemical screening strategy to differentiate Glucocorticoid-Remediable Aldosteronism (GRA) from Aldosterone-Producing Adenoma (APA). The approach combines a 1-mg overnight dexamethasone suppression test (ODST) with LC-MS/MS steroid profiling. We aim to establish diagnostic cut-off points for aldosterone and hybrid steroid (18-oxoF, 18-OHF) suppression rates as an efficient screening tool prior to genetic testing.

Background:

GRA is a rare form of primary aldosteronism where aldosterone secretion is regulated by ACTH. This study evaluates if a 1-mg ODST can effectively suppress aldosterone and hybrid steroids in GRA patients compared to the autonomous secretion observed in APA.Methods:

• Participants: Patients with genetically confirmed GRA or clinically/pathologically confirmed APA are enrolled.
• Procedure: Patients undergo a 1-mg ODST (1 mg dexamethasone at midnight). Blood samples are collected at 08:00 AM at baseline and post-suppression.
• Analysis: 11 steroids, including ALD, 18-oxoF, and 18-OHF, are measured via LC-MS/MS.
• Evaluation: Diagnostic performance is assessed using ROC curves and negative predictive value (NPV) based on a 1% GRA prevalence.Perspective:

This initial phase establishes the diagnostic parameters, which will be further validated in a larger cohort to optimize the screening workflow for primary aldosteronism.

Inclusion Criteria:

• Patients diagnosed with Primary Aldosteronism (PA) according to clinical biochemical screening standards.

GRA Group: Genetically confirmed presence of the $CYP11B1/CYP11B2$ chimeric gene.

APA group：The patient was diagnosed with PA and the adrenal imaging showed a typical adrenal adenoma on one side. The AVS or Ga68-Pentixafor PET/CT indicated that the adrenal gland on the adenoma side had a dominant secretion of aldosterone. And any of the following conditions was met: (1) The postoperative pathology clearly confirmed an adrenal cortical adenoma, with immunohistochemistry showing aldosterone synthase CYP11B2 (+). (2) After unilateral adrenal resection, the biochemical results of the patient were completely relieved, meeting the surgical outcome criteria for PA.

Exclusion Criteria:

• Exclude patients with secondary hypertension caused by other reasons (such as Cushing's syndrome, pheochromocytoma), severe cardiac and renal insufficiency (eGFR < 30 mL/min/1.73m²), or those who are unable to cooperate to complete the trial process for various reasons.

The study population consists of 31 patients diagnosed with Primary Aldosteronism (PA), including 8 cases of genetically confirmed Glucocorticoid-Remediable Aldosteronism (GRA) and 23 cases of Aldosterone-Producing Adenoma (APA).