SAT-438 Current Glucocorticoid Weaning Practice and Rate of Hypothalamic Pituitary Adrenal Axis Recovery in Patients with Treated Unilateral Adrenal Cushing's, Mild Autonomous Cortisol Secretion or Glucocorticoid Induced Adrenal Insufficiency

Abstract Disclosure: S.S. Lui: None. L. Cheong: None. R. Parameswaran: None. R. Chatterjea: None. C. Khoo: None. P. Eng: None. Background: Prolonged glucocorticoid (GC) exposure can suppress the hypothalamic-pituitary-adrenal axis (HPA) axis, leading to GC-induced adrenal insufficiency (GC AI). Limited data exists on GC weaning rates and practices to achieve HPA axis recovery in clinical settings. Aim This study aimed to evaluate GC weaning practices and rates for HPA axis recovery in patients with GC AI and post operative AI. Methods: This retrospective cohort study included patients referred to our endocrine clinic between 01/01/2024 and 01/01/2025, for suspected AI. We included patients who had GC AI due to prior exogenous GC use and patients after adrenalectomy for adrenal Cushing’s (AC) or mild autonomous cortisol secretion (MACS). Patients with secondary AI were excluded. Successful weaning was defined as being GC free 12 months after the initial outpatient review. Results: Thirty patients had GC AI due to prior exogenous GC use and 11 patients had GC AI following surgery for unilateral AC (5 cases) or MACS (6 cases). Among the 30 patients with GC AI, 19 (63.3%) were started on hydrocortisone and 10 (33.3%) were commenced on prednisolone. Of these, 40% (12/30) were successfully weaned off GCs over a mean period of 8.9 months, requiring at least 2-3 clinic appointments. However, 18/30 patients (60%) remained on GC after a year. Causes for GC AI included prior exposure to oral steroids (43.3%), inhaled steroid (13.3%), topical steroid (6.7%) and traditional/herbal medicine use (36.7%). Hydrocortisone was the preferred steroid during weaning, with a mean dose reduction of 2.5 mg per month. Patients underwent an average of two SSTs during the weaning process. In the AC/MACS group, 63.6% (7/11) were successfully weaned over 8.3 months, requiring 4 clinic visits on average. The rate of hydrocortisone reduction was faster in the AC/MACS group (5mg/month vs 2.5 mg/month in the GC-AI group (p=0.04)). The AC/MACS group had lower baseline cortisol levels (AC/MACS: 58.1 ± 64.8 nmol/L vs GC AI: 157.5 ± 51.8nmol/L, p<0.0001) and was started on a higher hydrocortisone dose (AC/MACS: 23.4±9.4 mg vs GC AI: 18.0±8.8mg). They were also younger (Mean age in AC/MACS: 44.5 ± 11.4years vs GC AI: 59.1 ± 15.8years, p=0.008) and had fewer comorbidities. No patients were admitted for adrenal crisis during the GC weaning process. Reported symptoms during weaning were minor, with dizziness reported in 12.6%, fatigue in 10.1% and 2.5% presenting with transient hypotension. Conclusion: Patients with postoperative AI secondary to AC/MACS were weaned faster (5mg hydrocortisone/month) than patients with GC AI (2.5mg of hydrocortisone/month), reflecting different recovery trajectories. Overall, a weaning rate of 2.5-5 mg is safe and effective in these patients, with no reported severe adrenal crisis. Presentation: Saturday, July 12, 2025