Endocrine Abstracts

Prevention and early treatment of hypoglycaemia in young patients with congenital hyperinsulinism (HI) is essential for reducing the risk of neurological and fatal consequences as well as optimising treatment. Continuous glucose monitoring (CGM) provides more comprehensive glucose measuring and the ability to alert when hypoglycaemia occurs. Some studies suggest that CGM can be a helpful tool in the management of HI alongside capillary blood glucose (CBG). FreeStyle Libre 3 (FSL3) is a recent generation CGM that has improved accuracy and smaller size, which can be particularly beneficial for use in infancy, the age when most patients with hyperinsulinism are diagnosed. In our centre, FSL3 was utilised for two patients with HI in adjunct to 4 hourly CBG measurements during inpatient admissions to hospital.

Patient A: 6 month old female, diagnosed with HI in the neonatal period (genetics for HI negative for known mutations). Non-responsive to Diazoxide and started on increasing doses of Octreotide up to 25.5 mg/kg/d. She received nasogastric feeding with Infantrini Pepisorb and Maxijul (glucose 12.7%) continuously overnight and 3hourly in the day. She was admitted to the hospital for recurrent hypoglycaemia. Over a 4-day admission, she had 6 episodes of hypoglycaemia, 5 of which were identified by FSL3 prompting additional CGB checks.

Patient B: 16 month old female, diagnosed with HI at 12 month (genetics showed paternally inherited ABCC8 pathogenic variant). Non-responsive to Diazoxide and started on increasing doses of Octreotide up to 11.7 mg/kg/day. She was fed via gastrostomy with Nutrini continuously overnight and 2 feed boluses during the day. She was admitted to hospital for 11 days due to vomiting and recurrent hypoglycaemia. She had 5 episodes of hypoglycaemia requiring treatment, 4 of those were identified by FSL3 prompting an early CBG measurement. A total of 9 asymptomatic hypoglycaemic events (glucose <3.5 mmol/l) were additionally identified by the FSL3 low glucose alarm which occurred out with the routine times for CBG. Hypoglycaemia ranged between 2.1- 3.4 mmol/l. Our experience in two infants with HI highlights the potential benefits for early hypoglycaemia recognition by using FreeStyle Libre 3 in conjunction with CBG in young patients with recurrent hypoglycaemia.