by Amy Sanghavi Shah, MD, MS

The Medtronic advanced hybrid closed loop (AHCL) system uses automated basal (background) insulin delivery but adds two new features, automatic correction boluses and the ability to set different glucose targets. Data on the safety of the Medtronic AHCL automated insulin delivery system was presented at the 2020 ADA Scientific Sessions. This study is highly relevant since using hybrid closed loop therapy is increasing in popularity.

The trial studied safety of the AHCL in 157 adolescents and adults with T1D who were on pump therapy with or without continuous glucose monitoring. The authors reported that AHCL therapy improved the mean HbA1c from 7.5% to 7.0%. Furthermore, almost twice as many patients achieved an HbA1c ≤7.0% with AHCL therapy vs. baseline, and more participants achieved a TIR of 70-180 ≥70%, which further increased for all groups when the basal target set point was lowered to 100 mg/dL. Importantly, there were no serious or unanticipated adverse device effects.

Dosing insulin at mealtime can be a real challenge for people with T1D, as they try to make sure they are giving the right amount of insulin, at the right time, for each meal. The ability to combine automated basal and correction boluses using the AHCL system is designed to help accommodate for inexact carbohydrate counting or occasionally missed meal doses. The technology helps prevent lows and highs and improves time in range.

There is much interest in the future of advanced technology to treat T1D and the AHCL system is a significant step forward to automate insulin delivery. In T1D, the aim is to improve long-term outcomes and prevent diabetes-related complications, which are mostly related high and low blood glucose levels and long-term glycemic control. These results help demonstrate the safety and efficacy in maintaining better time-in-range and glycemic control without the risk of hypoglycemia. Closed loop systems are continually improving and are a substantial improvement over past management tools.