Real-World Implications of Hybrid Close Loop (Hcl) Insulin Delivery System

Abstract

Objective: Clinical trial data demonstrates improved glycemic control with hybrid close loop (HCL) insulin delivery systems, yet limited real-world data exists. Data from the inaugural cohort of patients initiating a HCL system (Medtronic MiniMed™ 670G, Medtronic Canada, Brampton, ON) at a university medical center was used to examine real-world utilization and glycemic control following a standardized implementation process. Methods: Data from 34 adult patients with type 1 diabetes were obtained from pump downloads at 4 time points: (1) previous insulin pump, (2) HCL in manual-mode, (3) 2 weeks after HCL auto-mode transition, and (4) 6 to 12 weeks after initiation of HCL. In-person training by certified diabetes educators was performed across 3 sessions with phone and electronic messaging following auto-mode start. Results: Mean self-monitored blood glucose (SMBG) per day increased from 5.15 baseline to 6.49 at 6 to 12 weeks (P<.05) with 3.26 sensor calibrations per day. Time-in-auto-mode was 79.3% at 2 weeks and 72.3% at final follow-up, with 82% of patients spending >50% of time in auto-mode. There were 8.2 auto-mode exits over the final 14-day download. Time-in-target was 67.3% in manual-mode, 73.4% at 2 weeks (P = .09), and 71.7% by 6 to 12 weeks (P = .06). Hemoglobin A1c (HbA1c) decreased by 0.51% (P = .02), while total daily dose and % basal did not change. Patients with HbA1c <7.0% (53 mmol/mol) at baseline spent more time-in-target than those with HbA1c ≥7.0% (53 mmol/mol; 78.0% versus 67.5%) despite spending less time-in-auto-mode (66.5% versus 74.8%). Conclusion: These data illustrate real-world implementation of HCL technology using a structured education program within a major medical center. Overall benefit may vary based on baseline characteristics such as HbA1c. Abbreviations: CDE = certified diabetes educator; HbA1c = hemoglobin A1c; HCL = hybrid closed loop; SMBG = self-monitored blood glucose.