Endocrine Abstracts

Introduction: Hybrid closed loop (HCL) therapy has been shown to improve the glycaemic control in children and adolescents with Type 1 Diabetes. There is however limited data comparing the HCL therapy with conventional insulin pump therapy. We aimed to retrospectively compare the outcomes of hybrid closed loop (Tandem T slim) and conventional insulin pumps.

Methodology: Electronic patient records for all the patients using insulin pump therapy at Sheffield Children’s Hospital were reviewed (98 patients). Data for 62 patients (between November 2016 to November 2021) were analysed. 8 patients on HCL who had previously been on a conventional pump were excluded. Mean or median HBA1c prior to starting the pump were compared with values at six weeks, six months and Twelve months between the groups using paired-T test. We also compared TIR, Hypoglycaemia, variability over the duration of one year.

Results: Results from 22 patients with HCL (mean age-9.25years, mean duration of diabetes -23 months) and 34 patients with conventional pump (mean age-7.5years, duration of diabetes -12 months) were compared. Median HBA1C in the HCL group decreased from 54.5±8.4 mmol/mol at baseline to 49.4±7.5 mmol/mol at 6 months (P=0.242) and 51.0±6.3 at one year (P-0.1723) after pump initiation. HBA1C in the conventional pump therapy improved from 53.7±7.39 to 52.9±8.8 at 6 months with no change at 12 months. The Average TIR (3.9-10 mmol/l) measured by Dexcom CGM in the first year was 49% with HCL compared to 44.9% with the conventional pump. No DKA was recorded in these groups. The variability did not change between the groups over one year (37% and 37.5%). HCL group had lesser hypoglycaemia (3.1%) compared to 4.1% in conventional group.

Conclusion: Patients with Hybrid closed loop had a better Time in range and lesser incidence of hypoglycaemia. There was an improvement of HBA1C with the Hybrid closed loop noted at 6 months and one year. HCL appears to have a better performance with only a modest improvement in HBA1C, likely due to the smaller sample size and/or good diabetes control prior to pump initiation.