Abstract

Children with type 1 diabetes (T1DM) constantly balance carbohydrate intake with insulin dose to achieve normoglycemia. TIDM is challenging especially when it is associated with a metabolic condition which restricts dietary intake or affects blood sugar. We review two cases of T1DM, one associated with Phenylketonuria (PKU) the other with medium-chain acyl-CoA dehydrogenase deficiency (MCADD).

Case 1: A 4-year-old boy with classical PKU on a phenylalanine restricted diet presented with T1DM. He was started on basal bolus regime after intensive carbohydrate counting.

The dietary plans can be conflicting and challenging. Foods low in phenylalanine such as fruit and sugar eaten without restriction previously, must now be eaten in moderation. Complex carbohydrates such as rice need to be both carbohydrate counted and their phenylalanine levels checked adding to meal time complexity. Hypoglycaemic episodes require additional planning, fast acting carbohydrates are taken without restriction, but longer acting carbohydrates containing wheat flour should be avoided due to high phenylalanine levels.

In PKU with TIDM carbohydrate counting is crucial and gives children more flexibility in an otherwise rigid diet. Previous case reports of PKU with TIDM suggest lower phenylalanine post TIDM diagnosis showing good control of both condition is achievable.

Case 2: A 17-year-old female was diagnosed with MCADD at 1 year and T1DM at 6 years. Her MCADD meant she was prone to hypoglycaemia, as a build-up of fatty-acid intermediates inhibited gluconeogenesis. Her insulin dose had to be carefully titrated to avoid this, particularly as she could not produce ketones to use as an alternate energy source. This reduction in ketone production lead to false reassurance when the child presented with high sugars. Our patient was prone to hypoglycaemia during infection and other catabolic states for which she required an emergency regime of glucose polymer drinks balanced with insulin intake.

In managing a metabolic disorder and TIDM patients are trying to achieve multiple outcomes including euglycaemia, preventing catabolism and in one case low phenylalanine levels. These complex multi disease states put a huge strain on families. Patients need comprehensive individual care plans, intensive structured education, multi-disciplinary team approach with specialist dietitian involvement.