Endocrine Abstracts

Background: Increased endogenous post-prandial GLP-1 release is a key mediator of improved glycaemic control following Roux-en-Y gastric bypass (RYGB) surgery. GLP-1 receptor agonists (GLP-1 RA) augment glucose-stimulated-insulin-release and suppress glucagon release, and do not usually cause hypoglycaemia. The use of GLP-1 RA have been shown to be safe for patients requiring additional glycaemic control following RYGB. We present a case of severe recurrent fasting nocturnal hypoglycaemia with semaglutide use following RYGB in a patient with autonomic dysfunction and hepatic fibrosis.

Case: A 54 year old Caucasian woman with obesity (BMI 44.9 kg/m²), T2DM (7 year duration), peripheral neuropathy and autonomic dysfunction, non-alcoholic steatohepatitis with F2 fibrosis, hypertension, bile salt malabsorption, GORD, and sleep apnoea underwent RYGB surgery. Pre-operatively she was treated with metformin, empagliflozin, liraglutide and pre-mixed insulin. 18 months post-operatively, her weight plateaued at 16 kg (13.6%) weight loss. Metformin and empagliflozin provided suboptimal glycaemic control with HbA1c 55 mmol/mol. She commenced semaglutide 0.5 mg subcutaneously once weekly. This augmented her weight loss (further 10 kg loss in subsequent 18 months) but she began reporting symptoms of hypoglycaemia that were unrelated to eating.

Results: Continuous glucose monitoring captured a pattern of recurrent severe nocturnal hypoglycaemia. This abated upon stopping all diabetic medication, and re-appeared on re-introduction of semaglutide 0.5 mg SC OW alone.

Discussion: We postulate that the presence of autonomic dysfunction in this case may inhibit counter-regulatory hormones protecting against hypoglycaemia. Clinicians using GLP-1 RA following RYGB should be alert to the possibility of impaired protection against hypoglycaemia.