Examining the efficacy of a closed loop system for treating type 1 diabetes

August 28, 2020
Miranda Hester

Ms. Hester is Content Specialist with Contemporary OB/GYN and Contemporary Pediatrics.

Type 1 diabetes treatment has improved dramatically over the years. A new study examines the efficacy of a closed loop system.

The treatment for type 1 diabetes has changed tremendously in recent decades and led to increasingly better outcomes for children. A study in the New England Journal of Medicine looked at whether a closed-loop system of insulin delivery called an artificial pancreas could improve the glycemic outcomes for children who had type 1 diabetes.1

The researchers conducted a multicenter, randomized, open-label, parallel-group trial that ran for 16 weeks. The participants were assigned in a 3:1 ration to be given treatment either with a closed-loop system of insulin delivery or a sensor-augmented insulin pump, the control group. The researchers’ primary outcome was the percentage of time that a participant’s glucose level was within the target range of 70 mg to 180 mg per deciliter, found through continuous glucose monitoring. The participants were aged 6 to 13 years of age.

The study recruited 101 children who were randomized: 78 were put into the closed-loop group and 23 were put into the control group. The average percentage of time where the glucose level was in the target range increased from 53±17% at the study’s baseline to 67±10% in the closed-loop group. In the control group, there was an increase from 51±16% at the study’s baseline to 55±13%. Across both of the groups, the median percentage of the time that the glucose level was below the lower end of the target range was low (1.6% in the closed-loop group and 1.8% in the control group). Among the participants in the closed-loop group, the median time that the system spent in the closed-loop mode was 93% (interquartile range, 91 to 95). Neither group had an episode of diabetic ketoacidosis or severe hypoglycemia during the study period.

The researchers concluded that the participants who used the closed-loop system had a glucose level that fell in the target range for a greater amount of time than the sensor-augmented insulin pump. The results give hope that the closed-loop system could help type 1 diabetes patients obtain even better outcomes.


1. Breton M, Kanapka L, Beck R et al. A randomized trial of closed-loop control in children with type 1 diabetes. NEJM. 2020:383(9):836-845. doi:10.1056/nejmoa2004736