Closed-Loop Tech Improves Daytime Blood Sugar Control for Type 1 Diabetes

Richard Bergenstal, MD

A closed-loop system may lead to improved daytime blood sugar control in adolescents and young adults with type 1 diabetes.

The findings, presented as part of the American Diabetes Association's (ADA's) 80th Virtual Scientific Sessions, suggested Medtronic’s Advanced Hybrid Closed-Loop system would not increase hypoglycemia in such patients.

“There is much interest in the future of advanced technology to treat type 1 diabetes and the (Advanced Hybrid Closed-Loop) system is a significant step forward for adolescents or young adults who have a hard time managing their glucose levels,” Richard Bergenstal, MD, said in a statement.

Bergenstal, the executive director of the International Diabetes Center at Park Nicollet in Minnesota, and a team of investigators compared the efficacy and safety of a next-generation automatic insulin delivery system (Medtronic’s Advanced Hybrid Closed-Loop) to 1 of 2 currently approved systems in the US (Medtronic’s 670G Hybrid Closed-Loop). The team enrolled 113 patients with type 1 diabetes at 7 international diabetes centers. Participants were adolescents and young adults aged 14-29 years old.

The participants used each automated insulin delivery system for 3 months during the randomized crossover trial. Each participant and their care team received standardized pump training, including how to account for meals and exercise.

The investigative team compared how effective each system was at preventing high blood glucose levels during the day, which was the biggest challenge for automated insulin systems prior to the study. They also evaluated how participants adjusted to the daily use of the system.

The team found the percentage of time in range over 24 hours, or the blood sugar levels from 70-180 mg/dL, was superior with the Advanced Hybrid Closed-Loop system. The time in range went from 57% at baseline to 67% for the Advanced Hybrid Closed-Loop system and 63% for the Hybrid Closed-Loop system.

More patients achieved international time in range consensus target of >70%. The number of individuals who achieved the feat went up nearly three-fold from baseline when using the Advanced Hybrid Closed-Loop system compared to increasing almost two-fold when using the Hybrid Closed-Loop system.

A1C levels decreased more for patients using the Advanced Hybrid Closed-Loop system. The baseline average levels were 7.9% and decreased to 7.4% with the Advanced Hybrid Closed-Loop system versus 7.6% with the Hybrid Closed-Loop system.

Both of the systems were found safe when evaluating events of level 3 hypoglycemia or diabetic ketoacidosis. Users, however, responding to a survey saying they preferred the Advanced Hybrid Closed-Loop system over the Hybrid Closed-Loop system.

Typically, the age group studied have a difficult time achieving optimal blood sugar control, which is important to reduce complications associated with type 1 diabetes. While patients can have multiple daily injections or pumps and continuous glucose monitoring, there is still a need to improve glycemic control without adding to the pre-existing burden of the condition.

“This age group has traditionally been the most difficult group in which to optimize glucose management and the FLAIR study shows that individuals using any type of therapy, even insulin injections without a pump or continuous glucose monitoring system, can benefit from the next generation (Advanced Hybrid Closed-Loop automated insulin delivery) therapy,” Bergenstal said.

The study, “FLAIR—An NIDDK-Sponsored International, Multi-site Randomized Crossover Trial of AHCL vs. 670G,” was presented at ADA 2020.