Artificial Pancreas 'Superior' in Young Kids With Type 1 Diabetes

Miriam E. Tucker

March 15, 2023

A hybrid closed-loop automated insulin delivery system improved time-in-range for blood glucose compared with standard care for kids with type 1 diabetes in a 13-week trial.

The hybrid closed-loop system, also called automated insulin delivery or artificial pancreas, was comprised of a t:slim X2 insulin pump, a Dexcom G6 continuous glucose monitor (CGM), and Control-IQ technology system algorithm software (Tandem Diabetes Care). The system was approved in the United States in 2018 for adults and children as young as 6 years.

Type 1 diabetes treatment is particularly challenging in children younger than 6 because of their small insulin dosing requirements and unpredictable eating and activity habits, say lead author R. Paul Wadwa, MD, of the Barbara Davis Center for Diabetes, University of Colorado, Aurora, and colleagues, in their article.

Thus far in the United States, only the Medtronic MiniMed 770G and the Omnipod 5 automated insulin delivery systems are approved for children as young as 2 years, they note.

In the current study of 102 children with type 1 diabetes aged at least 2 years but younger than 6 years, time-in-range over 13 weeks was higher for those randomized to the hybrid closed-loop system compared with standard of care; the latter included either an insulin pump or multiple daily injections plus a separate Dexcom G6 CGM.

The hybrid closed-loop system added an average of about 3 hours in ideal blood glucose range over the 13 weeks, compared to no change with standard care.

Moreover, the trial was conducted during the COVID-19 pandemic, necessitating virtual care for most of the study participants. As a result, more than 80% of the training on use of the system and over 90% of all the visits were conducted virtually.

"Successful use of the closed-loop system under these conditions is an important finding that could affect the approach to initiating and monitoring the use of the closed-loop system and expand the use of such systems, particularly in patients living in areas without an endocrinologist but with reliable internet access," the investigators write.

Their findings were published online March 15 in the New England Journal of Medicine.

"These results suggest that in very young children, closed-loop systems are superior to standard care with respect to glucose control," notes Daniela Bruttomesso, MD, PhD, of the University of Padua, Italy, in an accompanying editorial.

"Moreover, they show that the closed-loop system can be started remotely in children in this age range, with results that are similar to those obtained when parents or guardians receive face-to-face education about the use of these systems. The closed-loop system used in this trial appeared to be safe and effective."

Bruttomesso added: "Although the results were solid, the trial period was only 13 weeks, and there were more unscheduled contacts in the closed-loop group than in the standard care group. In addition, the authors compared a closed-loop system with standard care, rather than in-person initiation of a closed-loop system with remote initiation."

More Time-in-Range, No Hypoglycemia With Automated System

The 102 children were enrolled in the trial between April 28, 2021, and January 13, 2022, at three different US study sites; 68 children were randomized to the closed-loop system and 34 children to standard care. All but one participant completed the 13-week study.

Both groups had virtual or in-person trial visits at 2, 6, and 13 weeks after randomization, and telephone contact at 1 and 10 weeks. Training was virtual for 55 of the 68 children in the closed-loop group (81%). A total of 91% of 407 study visits in the closed-loop and 96% of 204 study visits in the standard care group were also virtual.

The mean percentage of time spent in target glucose range (70-180 mg/dL) increased from 56.9% at baseline to 69.3% at 13 weeks for the closed-loop group, compared with virtually no change, from 54.9% to 55.9%, in the standard care group. The mean adjusted difference between the two groups was significant (P < .001).

The closed-loop group also spent significantly less time than the standard care group with glucose levels above 250 mg/dL during the study period (8.4% vs 15.0%; P < .001), had lower mean glucose levels (155 vs 174 mg/dL; P < .001), and lower A1c (7.0% vs 7.5%; P < .001).

However, time spent with glucose levels below 70 mg/dL (3.0% vs 3.0%; P = .57) and below 54 mg/dL (0.6% vs 0.5%) didn't differ between the groups. 

There were two cases of severe hypoglycemia in the closed-loop group and one in the standard care group. One case of diabetic ketoacidosis related to infusion set failure occurred in the closed-loop group versus none in the standard care group.

Bruttomesso commented that a virtual approach has several advantages over in-person visits, including "a more relaxed environment, lower travel costs, and greater ease of contact with clinicians."

At the same time, though, "patient preferences, possible legal issues, and accessibility to technology...are all important considerations in choosing the most appropriate way to communicate with patients at the initiation of a closed-loop system or during routine follow-up." The families of the patients in this trial had above-average incomes, she pointed out.  

Ultimately, she said, "A mix of face-to-face visits and virtual clinic meetings may become routine in the management of diabetes in young children."

The study was supported by the National Institute of Diabetes and Digestive and Kidney Diseases. Wadwa has reported receiving grants/contracts from Beta Bionics, Dexcom, Eli Lilly, and MannKind, travel fees from Eli Lilly, and lecture fees from Tandem Diabetes Care, and serves as a consultant for Dexcom. Bruttomesso has reported no relevant financial relationships.

N Engl J Med. Published online March 15, 2023. Abstract, Editorial

Miriam E. Tucker is a freelance journalist based in the Washington, DC, area. She is a regular contributor to Medscape, with other work appearing in The Washington Post, NPR's Shots blog, and Diabetes Forecast magazine. She is on Twitter: @MiriamETucker.

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