Endocrine Abstracts

Background: Non-type 1 diabetes mellitus (T1DM) and T2DM accounts for up to 4% of cases of paediatric diabetes. The most common form is maturity-onset diabetes of the young, however rarer forms exist.

This case highlights a number of important points to be considered when investigating patients with ketoacidosis that is not typical of T1DM. An understanding of the ketogenic pathway and knowledge of differential diagnoses for ketoacidosis and their appropriate investigations is key.

Case: Our female patient initially presented at 2 years of age with acute gastroenteritis, and a significant metabolic acidosis (pH 7.17), associated with elevated ketones and lactate. Laboratory blood glucose was 10.6 mmol/l. A diagnosis of severe dehydration secondary to gastroenteritis, with a reactive hyperglycaemia was made. Six months later she represented with lactic acidosis and ketosis during another acute illness. She was hyperglycaemic (lab glucose 62.1 mmol/l). However, symptoms resolved after the acute episode and she remained well. A personalised emergency regimen was devised to reduce the risk of decompensation during acute illness.

Over a 2-year period, the patient underwent repeat oral glucose tolerance tests which demonstrated gradual progression from normal, to impaired glucose tolerance to overt diabetes mellitus. Continuous glucose monitoring demonstrated significantly raised blood glucose levels on a daily basis, predominantly post-meals. Insulin was therefore commenced.

A number of investigations have been performed to determine a cause of her diabetes and metabolic abnormalities. Autoantibodies were negative. Despite extensive metabolic investigations no definitive underlying diagnosis has been determined but urinary organic acid results suggest a possible mitochondrial disorder.

Conclusions: Thorough investigation and individualised management plans are key in patients presenting with non-typical forms of diabetes mellitus. Managing metabolic and diabetic causes of ketoacidosis can cause a treatment dilemma. Mitochondrial causes of diabetes should be considered in patients presenting in this way.