Abstract
Aims: To assess the safety and efficacy of hybrid closed-loop (HCL) insulin delivery 24/7 vs. only evening and night (E/N), and on extended 24/7 use, in free-living children with T1D.Materials and methods: Pre-pubertal children (n = 122; 49F/73M, age: 8.6 ± 1.6, diabetes duration: 5.2 ± 2.3 years, insulin pump use: 4.6 ± 2.5 years, HbA1c: 7.7 ± 0.7%/61 ± 5 mmol/mol) from 4 centers were randomized for 24/7 vs. E/N activation of the Tandem Control-IQ system for 18 weeks. Afterwards, all children used the activated system 24/7 for 18 more weeks. Primary outcome was %time spent in 70-180 mg/dL glucose range (TIR).Results: HCL was active 94.1% and 51.1% of time on 24/7 and E/N modes, respectively. TIR from baseline increased more on 24/7 vs. E/N: 52.9 ± 9.5 to 67.3 ± 5.6 (+14.4%, 95CI: 12.4-16.7%) vs. 55.1 ± 10.8 to 64.7 ± 7.0 (+9.6%, 95CI: 7.4-11.6%), p = 0.001. Mean %time below range was similarly reduced from 4.2 and 4.6 to 2.7, and mean %time above range more on 24/7 mode: 41.9 to 30.0 (-11.9%, 95CI: 9.7-14.6%) vs. 39.8 to 32.6 (-7.2%, 95CI: 5.0-9.9%), p = 0.007. TIR increased through the whole range of baseline levels and always more with 24/7 use. The results were maintained during extension phase in those initially on 24/7 use and improved in those with initial E/N use up to those with 24/7 use. Neither ketoacidosis nor severe hypoglycemia occurred.Conclusions: Our study demonstrates the safety and efficacy of Tandem Control-IQ system in free-living children with T1D for both E/N and 24/7 use. 24/7 use shows better outcomes, sustained for up to 36 weeks with no safety issue. This article is protected by copyright. All rights reserved.