Endocrine Abstracts

Introduction: Hybrid closed-loop system (HCS) in Type 1 diabetes (T1D) management uses an automated algorithm to adjust basal insulin and administer correction doses to maintain glucose homeostasis. We have more children with HbA1c <58 mmol/mol. We aim to investigate if HCS contributed to this improvement.

Methods: We identified TID children who started on HCS in our hospital from the year 2019–2023. Our HCS are Medtronic continuous glucose monitoring (CGM) with Medtronic 670G and 780G pumps and Dexcom CGM with T-slim and DANA pumps. The start date of HCS was recorded. Mean HbA1c was analysed for the year before and the year after starting HCS. The results were compared to see if our patients’ glycaemic control improved. Statistical significance was determined using paired t-test. Data was obtained using our electronic patient record.

Results: 102 children commenced on HCS within our study period. We excluded 6 children due to insufficient data. Data was collected for 96 children (55% male, 45% female). The median age was 12.4 years. The mean HbA1c pre-HCS was 61 mmol/mol and this significantly improved to a mean HbA1c of 56 mmol/mol after HCS (P<0.0000004). 21 patients with a mean HbA1c of more than 69 mmol/mol had an impressive reduction of an average 15 mmol/mol post HCS (P<0.00005). For the remaining patients, mean HbA1c improved from 57 mmol/mol to 54 mmol/mol post-HCS (P<0.0006). Children on multiple daily injections had higher mean HbA1c (62.8 mmol/mol) pre-HCS when compared to those on insulin pumps (60.8 mmol/mol). Both groups achieved similar mean in HbA1c in the year after HCS (55.8 mmol/mol). The number of children with HbA1c less than 58 mmol/mol increased from 37 to 55 children. 32 patients have HbA1c values at 2 years. More than half of them maintained HbA1c of <58 mmol/mol. Limitations to our study include short follow-up and variable HbA1c measurements due to the Covid pandemic and non-clinic attendances.ConclusionThere is significant improvement in our patients’ glycaemic control since the use of HCS. Although greater progress was seen in those with poorer metabolic control, a longer follow-up is needed in this patient group to see if these outcomes are sustained.