Performance of Tandem Control IQ during outdoor physical activity in children and adolescents with type 1 diabetes

Background: Few data are available in children with type 1 diabetes (T1D) using automated insulin delivery systems during physical activity (PA). We evaluated the time in range (TIR) during 2-hours of outdoor PA in children using t:slim X2 with Control-IQ® technology. Materials and methods: Caucasian children and adolescents, aged 9-18 years using t:slim X2 with Control-IQ® technology were recruited during a local sporting event. Participants were divided into two groups: Group A practiced endurance activities for 60 mins (1000-meter run, a jump circuit) then power activities for 60 mins (80-meter run, long jump); Group B practiced power activities for 60 mins then followed by endurance activities for 60 mins. Ninety minutes before the physical activity, participants had lunch and self administered a low dose insulin, reduced by 50% compared to their regularly calculated meal dose per pump calculator. DexcomG6® data was downloaded. Results: 26 children were recruited, 2 refused physical activity. Participants were divided as follows: 13 in group A [7 males, median age 14.6 years] and 11 in group B [8 males, median age 13.5 year)]. The mean glucose level when PA started was similar between groups (p=0.06). Subjects in group B showed a higher TIR than those in group A (50.4% 95%CI 33.8-75) vs 39.6% (95%CI 26.9-58.3), respectively (p=0.39). A significantly better TIR in Group B (53.8%, 95%CI 30.2-96.1) compared to Group A (17.4%, 95%CI 7.3-41.7, p=0.02) was recorded during the first session. During the second session, TIR increased in both groups. There were no episodes of serious or severe hypoglycemia. Conclusions No serious or severe hypoglycemic episodes were recorded during physical activity performed 90 mins after lunch. Future studies using t:slim X2 with Control IQ® technology are necessary.