Endocrine Abstracts

Case History: 39-year- old female presented to Endocrine services in 2002 with recurrent symptomatic fasting and post-prandial hypoglycaemia. No other medical history of significance noted.

Investigations: Short synacthen test, oral glucose tolerance test (OGTT), several supervised 72- hour fasts. Imaging (anatomic and function) included CT A-P, EBUS, Octreotide scan and MRI Pancreas.

Results: Short Synacthen test: Basal Cortisol 258 nmol/l, 30 min cortisol 673 nmol/l OGTT: Fasting plasma glucose 4.0 mmol/l, post glucose load 3.8 mmol/l. Initial 72-Hour fast: plasma glucose 2.8 mmol/l, insulin 19.7 mU/l (0-16) and C-Peptide 851 pmol/l (140-1390). Repeat 72-hour fast several months later: plasma glucose 2.0 mmol/l with concomitant insulin level of 10.3 mU/l and C-Peptide >4000 pmol/l. Hydroxybutyric acid 0.80 mmol/l. All imaging studies were negative and failed to identify an underlying lesion and she was eventually diagnosed with NIPHS.

Treatment: Patient commenced on diazoxide with dietary advice regarding frequent low glycaemic index carbohydrate meals. She had progressive weight gain and later also developed renal impairment which led to discontinuation of diazoxide. A trial of Octreotide and later acarbose were prescribed but discontinued due to side effects. She was reluctant to try calcium channel blockers and continued to suffer from frequent daily post-prandial hypoglycaemic episodes which led to further weight gain. Our patient, subsequently sought advice from a weight loss specialist privately and was commenced on liraglutide 1.8mg OD which not only was beneficial with weight loss but importantly terminated her hypoglycaemia. She remains hypoglycaemia free on a maintenance dose of liraglutide 0.6mg OD which she continues to self-fund.

Conclusion: Noninsulinoma pancreatogenous hypoglycemia syndrome (NIPHS) is extremely rare in adults and typically causes post prandial hypoglycaemia. It results from an increase in the size and number of pancreatic beta cells islets with focal or diffuse hypertrophy and hyperfunction, also known as nesidioblastosis. Treatment can be challenging and includes pancreatectomy, calcium channel antagonists and diazoxide. Treatment with GLP-1 analogues in this cohort of patients has not been described. However, there are a few case reports in literature, describing use of GLP-1 analogues in the management of postprandial hypoglycaemia after Roux-en-Y gastric bypass. It is postulated that GLP-1 analogues not only slow the gut motility but in low glucose conditions, they induce a downregulation of insulin secretion and upregulation of the glucagon level with consequent glucose stabilizing effect.