12444 Steroid Profiling And Circadian Cortisol Secretion In Patients With Mild Autonomous Cortisol Secretion: A Single-Center Cross-Sectional Study

Abstract Disclosure: J. Saini: None. S. Singh: None. A.L. Ebbehøj: None. C.D. Zhang: None. R. Nathani: None. V. Fell: None. E. Atkinson: None. S. Achenbach: None. A. Rivard: None. R.J. Singh: None. S.K. Grebe: None. I. Bancos: None. Abstract Context: Mild autonomous cortisol secretion (MACS) is diagnosed based on post-dexamethasone cortisol>1.8 mcg/dL. Scarce evidence exists on steroid circadian secretion and steroid metabolome in MACS. Objective: To characterize 24-hour urine steroid metabolome in patients with MACS and determine circadian differences in urine steroid profiling and cortisol concentrations in patients with MACS versus referent subjects. Design: Cross-sectional study, 2018-2023. Setting: Referral center Participants: 72 patients with MACS and 72 age-, sex-, BMI-, and menopausal status-matched referent subjects. Measurements: Urine was collected over a 24-hour (h) period in separate day- and night-time collections. High-resolution mass spectrometry assay was used to measure 25 steroids. A subgroup of patients and referent subjects were admitted for every 2-hour serum measurement of free and total cortisol. Outcomes: Steroids, sums, and ratios Results: Patients with MACS had lower mcg/24h median androgens (2084 vs 3283, P