Aim
To describe the use of dilute insulin to treat Type 1 diabetes (T1D) in infancy using a Hybrid Closed Loop (HCL) system.
Methods
Case report.
Results
An 8 month old boy presented with vomiting, lethargy and polyuria on a background of static weight gain (8.8kg) for 3 months. Investigations demonstrated moderate diabetic ketoacidosis (DKA) and insulin infusion was commenced.
Diabetes antibodies: negative GAD, IA2 and ZnT8 and positive insulin antibodies, 9.9U/mL (<0.4). Neonatal diabetes genetic panel was negative. Consistent with early onset T1D.
Subcutaneous insulin was commenced. A total daily dose of 4units was required. Given small insulin requirements, Medtronic 640G pump and Dexcom G6 sensor were commenced on day 4 using diluted insulin 1:5 (50units Novorapid (0.5mL) + 2mL Normal Saline - 20units/mL).
Review six weeks post pump start highlighted extreme parental anxiety and fatigue. Issues included frequent breast feeding with difficulty quantifying carbohydrate intake, problematic transition to solids and reliance on the diabetes team for frequent insulin dose adjustment. He was admitted for transition to a HCL system and education, using the Medtronic 780G insulin pump and SmartGuard™, acknowledging the algorithm was not licensed for use at this age.
Table 1 shows that transition to HCL, improved glucose management indicator (GMI) and time in range (TIR) with greatest improvement in time spent with glucose >13.9mmol/l. Increased TIR reduces the risk of developing microvascular and macrovascular complications (1). Hypoglycaemia was similar using standard pump and HCL.
Reduction in boluses per day using HCL indicated significant reduction in parental workload. This reduced reliance on regular adjustments. There has been a significant improvement in parent reported quality of life including improved sleep.
Discussion/Conclusion
This case highlights HCL with diluted insulin is safe, effective and can improve glycaemic control, parental quality of life and reduce reliance on the diabetes team.