1354-P: Diabetes and Glycemic Outcomes after Pancreatectomy for Diffuse Congenital Hyperinsulinism

Introduction and Objective: Congenital hyperinsulinism (HI) is characterized by dysregulated insulin secretion causing severe, persistent hypoglycemia with risk of neurological damage or death. In medically unresponsive diffuse HI, subtotal pancreatectomy may be pursued but is not curative and can lead to long-term health complications, including diabetes. This study characterized post-pancreatectomy diabetes and glycemic outcomes using patient-reported and continuous glucose monitoring (CGM) data from the HI Global Registry (HIGR). Methods: Individuals in HIGR with diffuse HI and ≥75% pancreatectomy were included. A subset was interviewed regarding surgical experiences and outcomes. Some participants shared Dexcom CGM data (any generation). CGM metrics included mean glucose, coefficient of variation (CV), and time below, in, and above range (TBR/TIR/TAR) for up to the most recent 30 days of data. Outcomes were summarized with descriptive statistics. Results: Of 323 individuals who completed the Surgical Management survey, 34 were included. 15 (44%) reported diabetes, 8 (24%) reported ongoing hypoglycemia treatment without diabetes, and 8 (24%) reported neither diabetes nor hypoglycemia medication. Interview participants noted challenges with rapid-onset hypoglycemia, commonly triggered by exercise, regardless of diabetes status. The mean CV among all individuals was 35% (27-45%). Among eight participants with diabetes who shared CGM data (6-29 yr follow-up), three had TAR >25% (18-32%), six spent >5% time above 250mg/dL, and two achieved TIR >70% (12-73%). Among five individuals without diabetes (2-14 yr follow-up), two had TIR <70% (62%-82%), and 4 did not meet level 2 glycemic targets. Conclusion: Subtotal pancreatectomy for diffuse HI is associated with glycemic dysregulation, including insulin-dependent diabetes and high glucose variability. Ongoing hypoglycemia was presented as a challenge by families, emphasizing the need for improved long-term monitoring and tailored treatment strategies after pancreatectomy. Disclosure K. Rohli: Research Support; Current; Rezolute Inc., Zealand Pharma A/S, Hanmi Pharm. Co., Ltd., Dexcom, Inc., Rhythm Pharmaceuticals, Inc. Other - Conference and event sponsor; Current; Amidebio. J. Raskin: Other - Research, conference, and event sponsor of Congenital Hyperinsulinism International.; Current; Rhythm Pharmaceuticals, Inc., Zealand Pharma A/S, Hanmi Pharm. Co., Ltd., Rezolute, Dexcom, Inc. Other - Conference and event sponsor of Congenital Hyperinsulinism International.; Current; Amidebio. T. Pasquini: Research Support; Current; Dexcom, Inc., Hanmi Pharm. Co., Ltd., Zealand Pharma A/S, Rezolute.