Unsupervised Closed Loop Insulin Delivery Feasible for Teens

BOSTON — Unsupervised, at-home, day-and-night closed loop insulin delivery appears to be safe and feasible in young patients with suboptimally controlled type 1 diabetes, a researcher reported at the American Diabetes Association (ADA) 75th Scientific Sessions.

At this year’s meeting, significance advances in the testing of closed loop technology were reported and one study in particular out of England involved testing that has now gone from the hospital setting to the home setting. The study is also notable because it involved adolescents and there has been a concern about potential hypoglycemia in children and teens with closed loop technology.

“Over the past few years, we have demonstrated that home use of closed loop overnight delivery is feasible, safe and effective,” Martin Tauschmann, MD, of the University of Cambridge in England, said during a presentation. He added that results from the first 24/7 monitoring studies in adults in the home setting demonstrated improved outcomes with closed loop delivery.

In studies, home use of overnight closed loop technology appeared to improve glucose control in adolescents with type 1 diabetes, but its use during the day has not been studied as it has in adults.

“Adolescents represent a more challenging population,” Tauschmann added. “Whether closed loop delivery is feasible and effective has yet to be investigated.”

To learn more, Tauschmann and colleagues conducted a free-living, open-label, crossover study in 12 children and adolescents with type 1 diabetes (mean age, 15 years; mean HbA1c, 8.3%; mean duration of diabetes, 8.2 years). All patients underwent two 7-day periods of closed loop insulin delivery or sensor-augmented insulin pump therapy with a 4-week washout period.

Patients underwent 2 to 3 hours of training on the closed loop system and were provided a 24/7 support line, but there was no at-home supervision. Other than recommendations to not use the system during strenuous exercise, the researchers imposed no restrictions.

A model predictive algorithm that automatically directed insulin delivery between meals and overnight during closed loop delivery was used in the all the patients during closed loop delivery. Prandial boluses were administered by patients themselves using a bolus calculator.

For this investigation, the primary endpoint was percentage of time spent when sensor glucose was in target range (70 mg/dL to 180 mg/dL).

They researchers found that glucose levels were in the target range 72% of the time with closed loop delivery vs. 53% of the time with sensor-augmented insulin pump therapy (P<.001). Further, glucose levels were greater than 180 mg/dL for 26% of the time with closed loop delivery vs. 43% with insulin pump therapy (P=.005).

Mean time spent with glucose levels below 70 mg/dL was 2.9% with closed loop delivery vs. 1.7% with insulin pump therapy (P=.87). Two episodes of hypoglycemia occurred, one with closed loop delivery and one with insulin pump therapy.

Results also indicated no differences in insulin outcomes, such as total daily insulin dose or insulin infusion rates.

“We concluded that 24/7 closed loop delivery for 7 days at home without supervision in teens with type 1 diabetes is feasible and safe. Closed loop delivery increased time in the target glucose range without increasing the risk for hypoglycemia,” Tauschmann said.

Reference

1. Tauschmann M et al. Abstract 221-OR: Day and Night Closed Loop Insulin Delivery in Young People with Type 1 Diabetes: A Free-Living, Randomised Clinical Trial. Presented at: American Diabetes Association (ADA) 75th Scientific Sessions; June 5-9, 2015; Boston.