What is the most appropriate next step in management?

An 18-year-old woman was referred by her general practitioner for further investigation of “funny turns” during which she developed palpitations, sweating, tremor, hunger, anxiety and paraesthesiae; all of these symptoms were relieved immediately by a sugary drink.

She was otherwise well and was not taking any regular medication. There was a family history of type 1 diabetes mellitus. A spontaneous hypoglycaemic episode had not been captured and she was admitted to the diabetes/endocrine ward for a 72-hour fast. Her renal function was normal.

After a 12-hour fast she experienced her typical symptoms. Urinalysis showed no urinary ketones.

Investigations after 12-h fast:

fasting plasma glucose 2.0 mmol/L (3.0C6.0)

plasma insulin56 pmol/L (<21 after hypoglycaemia)

serum C-peptide514 pmol/L (180C360)

What is the most appropriate next step in management?
A . coeliac axis angiography
B . MR scan of abdomen and pelvis to localise a mesenchymal tumour producing insulin-like growth factor 2
C . MR scan of pancreas to localise an insulinoma
D . obtain a careful history looking for access to exogenous insulin
E . request a urinary sulphonylurea screen on sample obtained during the fast

View Answer

Answer: E