1915-P: Continuous Glucose Monitoring Reveals Glycemic Profile Characteristics in Patients with Adrenal Insufficiency on Glucocorticoid Replacement Therapy

Introduction and Objective: Hypoglycemia is one of the clinical features of adrenal insufficiency (AI). Patients with AI require lifelong glucocorticoid replacement. However, whether glucocorticoid replacement therapy can restore physiological glycemic fluctuations in patients with AI remains unclear. We aimed to investigate the glucose fluctuation pattern in the patients with AI by Continuous glucose monitoring (CGM) and explore the association between CGM features and glucocorticoid administration. Methods: A total of 27 patients with a stable dose of glucocorticoids were enrolled. Fifty-four normal controls (NC) without known glucometabolic disorders were matched by age, sex, and BMI from a database of healthy volunteers. CGM was conducted in AI and NC with a blinded method for 14 days. The glucocorticoid regimen and adverse events during CGM were recorded. Results: The mean age of the AI group was 59.53±8.51 years, including 15 male. Compared with NC, the patients with AI had increased time below range (TBR, glucose <3.9 and <3.0 mmol/L), and decreased time in range (TIR, glucose within 3.9-7.8 mmol/L) during 24h, diurnal, and nocturnal periods. Time above range (TAR, glucose ≥7.8 mmol/L) during the lunch and dinner period were increased. The indicators representing glucose fluctuation were also increased. The patients taking glucocorticoid once per day had higher TAR during the lunch period than those with medication twice daily. Patients receiving hydrocortisone had a higher TAR during the breakfast and lunch periods than those taking prednisone. Patients with immune checkpoint inhibitors induced AI had higher glucose levels and fluctuation during the breakfast and dinner periods than those of the other etiology. Conclusion: Patients with AI undergoing glucocorticoid replacement therapy exhibited more asymptomatic hypoglycemia and larger glucose fluctuation. CGM may provide valuable information in determination of proper glucocorticoid administration of AI. Disclosure R. Zhang: None. C. Ning: None. Q. Ren: None. L. Ji: None. Funding National Natural Science Foundation of China (82470859), the Beijing Natural Science Foundation (7242157), Noncommunicable Chronic Diseases-National Science and Technology Major Project?2025ZD0549400?2025ZD0549401?and the 2024 National Clinical Key Specialty Construction Program of China (Department of Endocrinology, Peking University People's Hospital) with support from the central government budget.