Endocrine Abstracts

Background: Hypoglycaemia is a common presentation in paediatrics, linked to rare endocrine pathologies. This case highlights potential pitfalls when assessing and managing a child with hypoglycaemia.

Presenting problem: A 15-year-old, previously well female, presented with significant hypoglycaemia (2.2 mmol/l). A hypoglycaemia screen was performed which revealed an inappropriately low cortisol (111nmol/l), she was therefore treated for adrenal insufficiency. Despite this, the hypoglycaemia persisted. She had recurrent episodes (1.3-2.8 mmol/l) on maintenance hydrocortisone, stress dosing, in the absence of intercurrent illness or stress and in spite of an intravenous dextrose infusion. There was a family history of maternal diabetes, reported to be taking metformin. The patient was not on regular medication, over the counter medicine or herbal remedies and her psychosocial screening was unremarkable.

Clinical management: Further investigations included early morning cortisol (96nmol/l) and baseline cortisol on synacthen test <50nmol/l. Adrenal antibodies and ACTH were pending at this time. There was a one-month delay in receiving the initial hypoglycaemia screen insulin levels (due to delays associated with referal laboratory send away); insulin 308pmol/l and c-peptide 1540pmol/l. The endogenous insulin production raised concerns of an insulinoma. The patient was commenced on diazoxide at 7 mg/kg/day and underwent pancreatic imaging (ultrasound and MRI) which were unremarkable. Further imaging modalities were being considered, including octreotide scintigrophy, when her urine toxicology results were reported, revealing gliclazide (sulphonylurea) abuse. This was cross referenced with her mother’s GP records, with her mother’s consent. The patient successfully discontinued hydrocortisone and diazoxide. She was discharged with psychological support.

Discussion: This case highlights the role of counter-regulation and habituation in the context of hypoglycaemia, which need to be taken into account when interpreting results. It demonstrates value in considering urine toxicology early in teenagers presenting with hypoglycaemia. Ketones were not performed on the first hypoglycaemia screen and this simple bedside test holds great value in narrowing differentials. Of note diazoxide can be used as an effective treatment for sulphonylrea overdose. Whilst in this case there was some evidence of rare endocrine pathology, intentional overdose is far more common, as is medication non-compliance; clinicians should keep an open mind.