Closed-Loop Insulin System Keeps Glucose Levels in Range Longer Than Standard Care in Children With Type 1 Diabetes

A hybrid closed-loop system was shown to improve and maintain glucose levels in children aged between 2 and 6 years with type 1 diabetes (T1D) better than standard care.

Findings were published in the New England Journal of Medicine.

The t:slim X2 insulin pump with Control-IQ Technology system is a hybrid closed-loop system that automatically monitors and regulates blood glucose through advanced control algorithms. The artificial pancreas enables automated basal adjustments and bolus corrections delivered from an insulin pump every 5 minutes, adjusting the insulin dose as needed.

A total of 102 children aged between 2 and 6 years with T1D were randomized 2:1 to the closed-loop or standard care group. Standard care included either an insulin pump or multiple daily injections of insulin in addition to a continuous glucose monitor.

The researchers measured the percentage of time that glucose level was in the target range of 70 to 180 mg per deciliter. As secondary outcomes, they also measured the percentage of time that the glucose level was above 250 below 70 mg per deciliter, and looked at the mean glucose level, glycated hemoglobin level, and safety outcomes.

After 13 weeks of follow-up, among the patients who used the closed-loop system, their glucose level was in the target range for a significantly longer time by about 3 hours per day, on average.

The mean (SD) percentage of time that the glucose level was within the target range increased from 56.7% (18.0%) at baseline to 69.3% (11.1%) after follow-up in the closed-loop group, marking a 12.6% increase. Meanwhile, this percentage only increased by 1% in the standard care group, going from 54.9% (14.7%) at baseline to 55.9% (12.6%) at week 13 (mean adjusted difference, 12.4%; 95% CI, 9.5-15.3; P < .001).

“The percentage of time that the glucose level was within the target range consistently favored the closed-loop system across a broad range of baseline characteristics, including age, sex, body mass index, household income, parental education level, use of an insulin pump or receipt of multiple daily injections of insulin before the trial, and glycated hemoglobin level,” the authors noted. “A greater increase in the percentage of time that the glucose level was in the target range and a greater decrease in the glycated hemoglobin level were observed with higher baseline glycated hemoglobin levels.”

Similarly, results regarding the percentage of time that the glucose level was above 250 mg per deciliter, the mean glucose level, and the glycated hemoglobin level all favored the closed-loop system.

For glucose levels, 21 (31%) of 68 patients in the closed-loop group and in 2 (6%) of 34 patients in the standard care group achieved having both 70% of time in target range and less than 4% of time with glucose level below 70 mg per deciliter.

Additionally, at baseline, glycated hemoglobin levels ranged from 5.2% to 11.5%. The American Diabetes Association recommends a glycated hemoglobin target level of less than 7%. In this study, 30 (48%) of 62 patients in the closed-loop group and 10 (30%) of 33 patients in the standard care group met this target at 13 weeks.

“We infer that the finding that patients with higher baseline glycated hemoglobin levels had the greatest improvement in the percentage of time that the glucose level was in the target range may be of public health importance for the prevention of long-term complications of type 1 diabetes,” the authors said.

There were no significant differences in the percentage of time that the glucose level was below 70 mg per deciliter between the closed-loop and standard care groups.

Of 102 total participants, 71 adverse events occurred in 41 participants in closed-loop group, and 14 events occurred in 11 participants in the standard care group. Additionally, 4 severe adverse effects occurred in the study sample, with 2 cases of severe hypoglycemia in the closed-loop group and 1 case in the standard care group recorded, as well as 1 case of diabetic ketoacidosis recorded in the closed-loop group.

Reference

Wadwa RP, Reed ZW, Buckingham BA, et al. Trial of hybrid closed-loop control in young children with type 1 diabetes. N Engl J Med. 2023;388(11):991-1001. doi:10.1056/NEJMoa2210834