MON-884 - Congenital Hyperinsulinism Beyond Childhood: Clinical Characteristics and Unmet Needs in Adults

Objective: Congenital hyperinsulinism (HI) is a rare condition where increased insulin secretion causes severe, recurrent hypoglycemia and is often perceived as a pediatric condition. While hypoglycemia resolves over time for some individuals, HI persists into adulthood for many, presenting long-term management challenges. In recent qualitative studies, adults with HI emphasized significant difficulties transitioning from pediatric to adult care, often encountering clinicians unfamiliar with the condition. Here, we characterized the adult population enrolled in the HI Global Registry (HIGR) to demonstrate ongoing clinical burden and the need for improved preparedness among adult endocrinologists.

Methods: Adults (>18 years) who completed at least one of the following surveys in HIGR were included: Diagnosis, Medication Management, Surgical Management, Glucose Monitoring, Diet and Feeding, or Other Medical Conditions. Descriptive statistics were used to summarize findings. Qualitative interviews from previous studies were analyzed for themes relating to clinical management in adulthood and transitioning care from pediatric to adult practitioners.

Results: Of 144 adults with HI enrolled in HIGR, 85 were included (age range: 18-80 years). Diffuse HI was reported by 45 (53%) participants. Genetic testing was reported by 58 (68%), of which 42 reported a variant in at least one HI-related gene, most commonly ABCC8 and GLUD1. At the time of survey, 31 (36%) reported currently taking an HI medication, including diazoxide (25, 29%), and less commonly, lanreotide (3, 4%), octreotide (1, 1%), sirolimus (1, 1%), steroids (1, 1%), and routine glucagon (1,1%). 17 (20%) participants had a pancreatectomy, and among these, 11 reported being diagnosed with diabetes. Ongoing glycemic instability was common. Of 59 participants who reported their frequency of hypoglycemia ( < 70 mg/dL), 32 (38%) reported lows at least once a week. Similarly, of 58 individuals who reported their frequency of hyperglycemia (>180 mg/dL), 17 (20%) reported at least weekly highs. Feeding issues persisted into adulthood, with 28 (33%) reporting a history of feeding challenges, and of those, 50% reported resolution. Across interviews conducted in two independent studies, young adults consistently described challenges of transitioning to adult care. They recounted difficulties in finding adult doctors with HI knowledge and experience, causing decreased satisfaction in their clinical management.

Conclusions: HI is often mischaracterized as a childhood disease, yet many individuals experience lifelong challenges. Adults with HI represent a clinically complex and underserved population within adult endocrinology. Improved education and awareness about congenital hyperinsulinism persisting into adulthood is urgently needed to support care of all individuals with HI.

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