Endocrine Abstracts

Hypoglycemia is not uncommonly encountered in healthy type 1 diabetics. It has diverse etiologies but food-insulin mismatch, exercise, drugs, co-existing adrenal, thyroid and coeliac disease, neuro-endocrine tumours & factitious hypoglycemia are the most common causes.

We describe the case of a 23-year old Caucasian male with type 1diabetes of 3-years duration with recurrent episodes of unexplained hypoglycemia. He was otherwise well and denied any systemic symptoms apart from weight loss in the last 18 months. He was a non-smoker and non-alcoholic. He had diabetic neuropathy but no nephropathy or retinopathy. He was injecting insulin Lispro (three times daily) and insulin Glargine at bed time but had poor glycemic control (HbA1c 9.1%).

He was admitted for further investigations to get to the bottom of his recurrent hypoglycaemic spells. Routine blood tests and biochemistry was normal. He was not acidotic and urinanalysis showed presence of ++ glucose and trace ketones. Short synacthen test and coeliac screen was normal. Pituitary hormone profile and IGF 2 & 3 were also normal. Toxicology and sulphonylurea screen were negative. US and CT abdomen was unremarkable.

He underwent a supervised prolonged fast in the hospital but had two episodes of hypoglycemia (BM’s 1.2 mmol and 1.6 mmol) within the first 8 hours needing treatment. Insulin levels were found 4 times in excess of normal with negligible levels of C peptide confirming factitious hypoglycaemia from surreptitious insulin use.

On direct confrontation, he admitted self-injecting insulin and also his ongoing social and family problems. He was out of work and his partners’ son was seriously ill. He subsequently saw a psychiatrist and was appropriately counselled. Bulk supply of his insulin was withdrawn and his treatment regimen modified. He was discharged with close community follow up. His GP was informed to give weekly supply of insulin and regular diabetes specialist nurse input was made as well.

Investigating recurrent hypoglycaemia can be a challenge. Whilst the obvious focus is to rule out an underlying endocrine aetiology, a thorough history and recognition of factitious cause is important and worth bearing in mind. This can be difficult to diagnose and often, can only be ruled out by extensive investigations and exclusion of other causes.