Endocrine Abstracts

Aim: To evaluate the impact of Hybrid closed loop (HCL) insulin pump therapy on children and young people with type 1 diabetes who had high HbA1c levels of ≥69 mmol/mol, prior to initiation of HCL therapy and to identify factors associated with suboptimal response to HCL therapy.

Methods: Our analysis focused on children with type 1 diabetes who had an HbA1c level of ≥69 mmol/mol at the time of initiation on Hybrid Closed Loop (HCL) insulin pump therapy. Outcomes assessed included changes in HbA1c, TIR, time above range (TAR), and the occurrence of significant hypoglycaemia or diabetic ketoacidosis (DKA). For patients who did not show improvement, potential contributing factors were explored.

Results: A total of 32 patients with baseline HbA1c >69 mmol/mol were included. The mean HbA1c decreased from 71.4 mmol/mol at initiation of HCL to 56.2 mmol/mol at 3 months and stabilised around 60 mmol/mol at both 6 and 9 months. By 9 months, only 7.2% of patients had a HbA1c above 68 mmol/mol. Common factors associated with lack of sustained improvement included missed meal boluses and failure to return to Auto Mode after switching to Manual Mode. The mean TIR improved from 34.9% at baseline to 58.3%, with this improvement of TIR >50% maintained over 12 months. Time above range decreased from a mean of 65% to 37.8%, with a notable reduction in the time spent in the very high range (from 37.6% to 11.3%). No significant hypoglycaemic events were reported during the study period. Two patients were admitted with mild DKA due to pump failure.

Conclusion: HCL insulin pump therapy significantly improved glycaemic control in children and young people with initially high HbA1c levels, in our cohort of patients. Improvements in HbA1c, TIR, and TAR were sustained over time, with no major safety concerns observed. Identifying and addressing behavioural patterns such as missed boluses and not reverting back to automode, may further enhance outcomes.