Poster 08: Metabolic effects of a Very Low Carbohydrate Ketogenic Diet (VLCKD) in a patient with HNF1A Maturity Onset of Diabetes of the Young (MODY)

Sheikh A; Nasir S; Flanagan C; Sibal L

Cambridge University Hospital
 

Very low carbohydrate ketogenic diets (VLCKDs) lead to an improvement in glycaemic control in the shorter term.  However, their safety and impact on cardiovascular risk in the longer term is not well understood. 

We report a 33-year-old gentleman who presented with osmotic symptoms and thrush. He had hyperglycaemia [fasting glucose 12 mmol/l, HbA1c 73 mmol/mol] without ketosis.  His father was diagnosed to have Type 2 diabetes in his early 30s and was treated with Metformin and Gliclazide. His mother had hypertension and was overweight. BMI was 24.8 kg/m2.  He was advised dietary modification for ‘Type 2’ diabetes.

He was referred to the secondary care due to diagnostic uncertainty. Examination was unremarkable with no acanthosis nigricans or lipodystrophy.

In the clinic, a random glucose was 6.6mmol/l, ketones 2.5mmol/l. His HbA1c had decreased from 78 to 48mmol/mol in 4 months on a VLCKD consisting of 5% carbohydrates, 85% fats, and 10% proteins per day, that was commenced since diagnosis

GAD-65, islet cell antibodies were negative. Genetic testing was undertaken. He persisted with the VLCKD (<5 gm carbohydrates daily).

Genetic testing subsequently confirmed a pathogenic variant in the HNF1A gene encoding the transcription factor hepatocyte nuclear factor 1 a. Although the glycaemic control improved on VLCKD, there was an overall deterioration in his lipid profile and cardiovascular risk scores, which improved on changing from a VLCKD to a low carbohydrate diet. 

This case highlights the effects of variations in dietary carbohydrate and fat intake on carbohydrate and lipid metabolism in patients with MODY.