Endocrine Abstracts

A 45-year-old female presented with recurrent episodes of neuroglycopaenic symptoms 6 years after Roux-en-Y gastric bypass surgery. Her symptoms occurred during both the fasting and postprandial state. She had a history of Rheumatoid Arthritis. Her symptoms did not response to a complex carbohydrate diet or Acarbose use.

Whipple’s triad was demonstrated during a 72 h fast; symptomatic hypoglycaemia (1.8 mmol/l) occurred which resolved with glucose administration. Simultaneous C-peptide, IGF1, IGF2 and insulin samples were requested during the hypoglycaemic episode.

The Insulin level was 10 pmol/l, IGF1 level was 11.6 nmol/l, the IGF2 level was 36.3 nmol/l, IGF2/I ratio was 3.1 (<10), C-peptide level was <94 pmol/l, GH was 7.5 μg/l and Sulphonlylurea screen was negative.

Ketones was ‘Zero’ confirming an insulin independent mechanism for hypoglycaemia. Hydroxcholoroquine for Rheumatoid Arthritis was discontinued which led to complete resolution of her symptoms.

This is the first case of severe hypoglycaemia in a patient who did not have diabetes, who underwent bariatric surgery and developed hypoglycaemia due to hydroxycholoroquine therapy with complete resolution of symptoms on discontinuing hydroxychloroquine.

This case demonstrates the need for a structured approach to the evaluation of hypoglycaemia. Roux-en-Y gastric bypass surgery is associated with subsequent development of hypoglycaemia which can respond to a complex carbohydrate diet or acarbose therapy. The lack of response however should prompt a thorough evaluation. The demonstration of an insulin independent mechanism for hypoglycaemia excluded post gastric bypass hypoglycaemia as a cause and prompted a review of the medication list. Hydroxcholoroquine is associated with the development of hypoglycaemia and cessation resulted in complete resolution of symptoms which were occurring at a frequency of 3–4 times per week resulting in termination of employment and driving.