Endocrine Abstracts

Objective: We examined our cohort of adults with type 1 diabetes who are using hybrid closed-loop (HCL) insulin delivery systems, to describe what proportion are meeting international targets of HbA1c, time-in-range, and time spent below range. We assessed longitudinal changes in HbA1c associated with switching from an open-loop to a HCL insulin pump.

Methods: We undertook a single-centre observational study of patients using Medtronic™ 780G insulin pump. Outcomes include sensor glucometrics and change in HbA1c.

Results: 184 participants with type 1 diabetes were included (median age 42 [IQR 31-53] years, 50% [n = 92] female, median duration of diabetes 26 [IQR 15-35] years). Mean duration of HCL pump therapy use was 18 (IQR 11-26) months. The majority (92.4%, n = 170) of participants had been previously treated with open-loop pump systems; 14 participants (7.6%) were treated with multiple daily injections and so were not included in the analysis of HbA1c change. Mean baseline HbA1c was 61.5 mmol/mol (±12.6 mmol/mol), and reduced to 56.8 mmol/mol (±10.6 mmol/mol) following transition to HCL pump (at 4-12 month clinical follow up) (-4.7 mmol/mol reduction, P < 0.001). The proportion of individuals with HbA1c of ≤53 mmol/mol rose from 26.6% to 38.7% (P = 0.001). Subgroup analysis was performed on 104 participants for whom CareLink™ data was available. The mean time spent in closed-loop mode (‘SmartGuard™’) was 90.6% (±12.2). Mean time-in-range was 70.4% (±10.9), and 52% of patients achieved a target of ≥70% glucose time-in-range. Mean time spent below range was 1.7% (±1.7) and 88% of participants spent <4% time below range.

Conclusion: In this real-world analysis of adults with type 1 diabetes, switching to HCL therapy was associated with improved glycaemic control evidenced by significant reduction in HbA1c levels, with a greater proportion of subjects achieving the internationally recommended glycaemic target of HbA1c ≤53 mmol/mol.