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08-26-2020 | Artificial pancreas systems | News

​​​​​​​Closed-loop system improves glycemic control in children with type 1 diabetes

Author: Claire Barnard


medwireNews: Children with type 1 diabetes who use the Tandem Control-IQ hybrid closed-loop insulin delivery system spend more time with their blood glucose levels in the target range than those using a sensor-augmented insulin pump, show findings from the iDCL trial.

As reported in The New England Journal of Medicine, the average proportion of time spent with glucose levels between 70 and 180 mg/dL (3.9–10.0 mmol/L), as measured by continuous glucose monitoring, increased from 53% at baseline to 67% during 16 weeks of treatment among the 78 children aged 6–13 years who were randomly assigned to receive closed-loop insulin delivery.

By comparison, average time in range increased from 51% to 55% among the 23 children in the control group, giving a significant mean adjusted difference of 11 percentage points between the two groups, which the researchers say was equivalent to 2.6 hours less time spent in hyperglycemia each day.

The Tandem Control-IQ system comprises a t:slim X2 insulin pump, the Control-IQ Technology software algorithm, and the Dexcom G6 continuous glucose monitor, while participants in the control arm used Dexcom G6 sensors plus either their personal insulin pump (for those who used one previously) or a t:slim X2 pump (for those who previously used injections).

R Paul Wadwa, from the Barbara Davis Center for Diabetes in Aurora, Colorado, USA, and fellow investigators say that the magnitude of treatment effect was “virtually identical” to that observed in an earlier iDCL trial involving adults and adolescents using the same hybrid closed-loop system, as reported previously by medwireNews.

The team notes that in the current study, “[t]he treatment effect was evident in the first month and appeared to be consistent” over the 16-week study period, and a greater benefit was seen for overnight compared with daytime glycemic control. Specifically, between midnight and 06:00, the average proportion of time in range was 80% in the closed-loop arm compared with 54% in the control group, whereas between 06:00 and midnight the corresponding values were 63% and 56%.

In subgroup analyses, Wadwa et al found that the percentage of time spent in range “consistently favored” closed-loop control compared with the sensor-augmented insulin pump “across a broad range of baseline characteristics,” including sex, age, BMI, previous insulin pump or injection use, and household income.

Overall, there were 16 adverse events (AEs) in the closed-loop arm and three in the control arm. One participant using the closed-loop system experienced a serious AE, namely hospitalization for gastroenteritis leading to ketosis that was not considered related to the device. There were no cases of severe hypoglycemia or diabetic ketoacidosis in either group, and the median number of hypoglycemic events was comparable in the closed-loop and control arms, at 0.5 and 0.6, respectively.

medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2020 Springer Healthcare Ltd, part of the Springer Nature Group

N Engl J Med 2020; 383: 836–845


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Novel clinical evidence in continuous glucose monitoring

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Jean-Pierre Riveline uses data from real-life continuous glucose monitoring studies to illustrate how these can uncover critical information about clinical outcomes that are hard to assess in randomized controlled trials.

This video has been developed through unrestricted educational funding from Abbott Diabetes Care.

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