Cambridge closed-loop system benefits very young children over 4 months of use
medwireNews: Closed-loop control with the Cambridge hybrid system improves time in range (TIR) in very young children with type 1 diabetes relative to sensor-augmented pump delivery over 16 weeks of use, researchers report.
Presenting the results of the randomized crossover trial at the virtual 57th EASD Annual Meeting, Julia Fuchs (University of Cambridge, UK) noted that although closed-loop control is known to work in this age group, the longest previous study lasted just 3 weeks.
And she cited data showing exceptionally high variability of insulin needs in these children, making closed-loop control an ideal approach.
The 74 study participants were enrolled in seven centers in five countries, and were aged between 1 and 7 years. The average age was 5.6 years and 36% were aged 2–4 years. The vast majority were already using a continuous glucose monitor.
The children undertook 16 weeks of closed-loop control and 16 weeks of sensor-augmented insulin pump use, in a randomly assigned order after a 2–4-week run-in period, with a 1–4-week washout period between the two study phases.
The closed-loop system comprised the Dexcom G6 glucose monitor, the Dana Diabecare RS insulin pump, and the Cambridge control algorithm. While using this system, participants had an average TIR (sensor glucose 3.9–10.0 mmol/L, 70–180 mg/dL) of 72%, which was significantly greater than the 63% achieved with sensor-augmented pump use.
This equated to an additional 2.1 hours/day within the ideal range, said the presenter.
The improvement was driven by a significant reduction in time in hyperglycemia, at a corresponding 23% with the closed-loop versus 32% with the sensor-augmented pump. There was no significant difference in time in hypoglycemia, at 4.9% and 4.5%, respectively.
Fuchs noted that time below range was relatively high at baseline, and glycated hemoglobin was low, and suggested this, as well as the lack of difference between the two interventions for this outcome, “is reflective of behaviors in this parent group in this population.”
The amount of time spent within the ideal blood glucose range remained consistent over the 4 months of use, reported Fuchs.
She also showed 24-hour insulin delivery profiles, which revealed markedly less insulin was delivered via manual bolus overnight during the closed-loop phase, relative to the sensor-augmented pump phase, with higher amounts instead being administered by the automatic system.
“That suggests that management burden is reduced with closed-loop, and parents are having to intervene less, particularly in the nighttime, to give corrections,” said the presenter.
There was just one incident of severe hypoglycemia during the trial, which occurred during the closed-loop phase and equated to an incidence rate of 4.5 per 100 person–years.
medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2021 Springer Healthcare Ltd, part of the Springer Nature Group