Endocrine Abstracts

JOINT283

A previously well 22-year-old female with no medical history presented obtunded to the emergency department. Capillary blood glucose returned “LO” with corresponding venous glucose at 2.1mmol/l. Prompt reversal of severe hypoglycaemia led to full resolution of symptoms. She continued to have multiple episodes of hypoglycaemia daily during her inpatient stay. Biochemistry revealed the cause of hypoglycaemia to be endogenous hyperinsulinaemia, accompanied with a clean toxicology screen and negative insulin antibody assessment. Interestingly, she was also hyperthyroid and concomitantly diagnosed with Graves’ Disease at the same encounter. Further history suggested that she may have had the hypoglycaemia disorder since early childhood for which she had been compensating for with lifestyle interventions. Genetic testing for congenital hyperinsulinaemia was inconclusive. Medical therapy with Diazoxide was initiated with good effect, with dose adjustments aided by continuous glucose monitoring. Etiology of hyperinsulinaemia was rigorously assessed, first with anatomical imaging of the pancreas (computed tomography and magnetic resonance imaging), followed by endoscopic ultrasound, all of which returned no positive result. Eventually, functional imaging with Exendin-4 PET/CT suggested a more diffuse process consistent with pancreatic islet cell hyperplasia.