923-P: Fasting Experience, Glycemic Control, and Fear of Hypoglycemia in People with Type 1 Diabetes Using Open-Source vs. Commercial Automated Insulin Delivery during Ramadan—A Multicenter Study from Saudi Arabia

Introduction and Objective: Open-source automated insulin delivery (OS-AID) has been shown to improve glycemic control in people with type 1 diabetes (PWT1D). We compare the effectiveness, safety, and fear of hypoglycemia (FOH) between OS-AID and commercial (C-AID) systems during Ramadan fasting. Methods: We recruited 114 PWT1D fasting during Ramadan 2024 using an AID system [OS-AID (n=7) or C-AID (n=107)] who agreed to share their CGM data from the month of Ramadan and the month before Ramadan. Comparative analyses focused on glycemic metrics and safety. Results: All OS-AID users had ≥bachelor degree and diabetes duration >10 years, compared to C-AID users (63.11% and 50.49%, respectively). Pre-Ramadan, there were no significant differences in the CGM metrics between the OS-AID and C-AID groups except for TBR<70 (3.9% vs 1.8%, respectively, p=0.01). During Ramadan, OS-AID users had significantly lower average glucose (139 vs 154 mg/dL, p=0.04), lower glucose management indicator (GMI) (6.5% vs 7%, p<0.1), lower time above range (TAR >180 mg/dL) (16.6% vs 25.84%, p=0.04), higher time below range (TBR <70 mg/dL) (3.29% vs 1.21%, p<0.01). Severe hypoglycemia events were low in both groups but higher in the OS-AID group (1.14 vs 0.07, p<0.01). There were no significant differences in the number of days during which fasting was broken because of diabetes nor in the levels of FOH post-Ramadan between groups. Conclusion: OS-AID system was as effective as C-AID systems in enabling PWT1D to fast most days of Ramadan and maintain glucose levels within target. In this small cohort, TBR and hypoglycemic events were slightly higher in the OS-AID group, both pre- and during Ramadan. These differences need to be confirmed with larger studies. They are likely driven by multiple factors, including limited healthcare provider support, understanding, and optimization of OS-AID systems during Ramadan. Disclosure S. Alharthi: None. M. Alsuhaibani: None. M. Almehthel: Advisory Panel; Novo Nordisk. Speaker's Bureau; Novo Nordisk. Research Support; Novo Nordisk. Advisory Panel; Sanofi. Speaker's Bureau; Sanofi. Research Support; Sanofi. Speaker's Bureau; Lilly Diabetes. Advisory Panel; Abbott. Speaker's Bureau; Abbott. Advisory Panel; Dexcom, Inc. Speaker's Bureau; Bayer Pharmaceuticals, Inc. T.H. Almigbal: None. A.M. Alhashem: None. R. Alamoudi: None. H.A. Zarif: Other Relationship; Abbott, Medtronic. A.M. Almurashi: None. N. Alzaman: None. S. Hussain: Advisory Panel; Tandem Diabetes Care, Inc, Dexcom, Inc., Medtronic, Sanofi, Vertex Pharmaceuticals Incorporated. Speaker's Bureau; Abbott, Insulet Corporation, Dexcom, Inc., Roche Diabetes Care. M. Al-Sofiani: Advisory Panel; Medtronic. Speaker's Bureau; Insulet Corporation, Abbott, Lilly Diabetes. Advisory Panel; Dexcom, Inc., Roche Diabetes Care. Speaker's Bureau; Sanofi. Research Support; Medtronic. Speaker's Bureau; Vitalaire.