282-OR: Impact of a Hybrid Closed-Loop Insulin Delivery System on Hypoglycemia Awareness in Individuals with Type 1 Diabetes

Background: Individuals with impaired awareness of hypoglycemia (IAH) are at risk of severe hypoglycemia. Although it is known that elimination of hypoglycemia can restore hypoglycemia awareness in this high-risk group, this has been challenging in real life. Technological advancements like closed loop system provide an opportunity to minimize hypoglycemia. Hence, the aim of this study was to evaluate whether a hybrid closed loop insulin delivery system can improve hypoglycemia awareness in individuals with IAH. Methods: Participants with type 1 diabetes and IAH (Gold Score ≥4) were randomized to either a hybrid closed loop system (Medtronic 670G) (intervention) or standard insulin pump therapy (control) for 8 weeks. Gold scores and hyperinsulinemic hypoglycemic clamp studies were undertaken at baseline and at the end of the study with evaluation of the hormonal and symptomatic responses to hypoglycemia. Results: A total of 17 participants completed the study (mean (SD) age 35.8 years (11.2), diabetes duration 24.2 years (11.3), HbA1c 7.8% (1.2)). 8 participants were randomized to control and 9 participants to intervention. The baseline (Median, IQR) Gold score was 6.0 (5.0; 6.0) in the overall cohort and did not differ between groups. At the study end, Gold score improved in the intervention group: control vs. intervention 6.0 (4.5; 6.0) vs. 3.5 (3.0; 4.5); p = 0.027. Symptom scores (adrenergic and neuroglycopenic) during the clamp were not different between the control and intervention groups. Conclusions: The use of a hybrid closed loop system over 8 weeks improved self-reported hypoglycemia awareness, however there was no evidence for improvement in the symptomatic responses to experimentally induced hypoglycemia. Disclosure M. Burckhardt: None. J. Dart: None. G.J. Smith: None. M.B. Abraham: None. N. Paramalingam: None. J.M. O'Dea: None. M. de Bock: None. E.A. Davis: None. T. Jones: Research Support; Self; Dexcom, Inc., Medtronic MiniMed, Inc. Speaker's Bureau; Self; Eli Lilly and Company, Roche Diabetes Care.