Background: Few data are available in children with type 1 diabetes using automated insulin delivery systems during physical activity (PA). We evaluated the time in range (TIR) during 2-h 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 min (1000-meter run, a jump circuit) and then power activities for 60 min (80-meter run, long jump); Group B practiced power activities for 60 min and then followed by endurance activities for 60 min. Ninety minutes before the PA, 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 were downloaded. Results: Twenty-six children were recruited, 2 refused PA. 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% confidence interval, 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 PA performed 90 min after lunch. Future studies using t:slim X2 with Control-IQ technology are necessary.
Keywords: Automated insulin system; Children; Hypoglycemia; Tandem Control IQ; Time in range; Type 1 diabetes.