Endocrine Abstracts

A 72 year old, non-diabetic, woman was referred with recurrent severe hypoglycaemia. Twenty-one years ago she was investigated for hypoglycaemia when inappropriate hyperinsulinaemia had been confirmed. Although a CT of her abdomen could not demonstrate an insulinoma she underwent a distal pancreatectomy and subsequent histology showed islet cell hyperplasia. She was managed with dietary intervention and diazoxide. At the time of the current referral she was suffering daily severe hypoglycaemic episodes requiring prolonged hospital admissions. A repeat 48 hr fast confirmed spontaneous hypoglycaemia and inappropriate hyperinsulinaemia (glucose 1.8 mmol/l, insulin 88 pmol/l, C-peptide 734 pmol/l). A sulphonylurea screen was negative. An abdominal CT showed no pancreatic lesion. Subcutaneous Lanreotide LA was administered with no improvement in symptoms. Further investigations showed evidence of malabsorption: folate 2.1 ug/l (RR 2.5–15.0), ferritin 7 ug/l (RR 12–250), Adjusted calcium 2.20 mmol/l (RR 2.20–2.60), PTH 21 pmol/l (RR 1.5–7.6) and Vitamin D 11.3 ug/l (RR 10–45) although she had no gastrointestinal symptoms. Endomysial antibodies were negative and an OGD was normal but the D2 biopsy showed sub-total villous atrophy consistent with coeliac disease. Within days of starting a gluten free diet her symptoms dramatically improved. She continues on diazoxide and reports only occasional, mild hypoglycaemic episodes.

This woman has a rare cause of spontaneous hypoglycaemia that had been well controlled for 20 years with dietary intervention and diazoxide. Her recent deterioration in symptoms was a result of malabsorption of carbohydrates and diazoxide secondary to coeliac Disease. With commencement of a gluten free diet she significantly improved and we were able to avoid long-term use of somatostatin analogues or further abdominal surgery.