Hybrid closed-loop with faster insulin aspart compared with standard insulin aspart in very young children with type 1 diabetes: A double-blind, multicenter, randomized, crossover study.

We evaluated the use of hybrid closed-loop (HCL) insulin delivery with faster insulin aspart (Fiasp) in very young children with type 1 diabetes (T1D). In a double-blind, multicenter, randomized, crossover study, children aged 2-6 years with T1D underwent two 8-week periods of HCL using CamAPS FX with Fiasp and standard insulin aspart (IAsp), in random order. Primary endpoint was between-treatment difference in time in target range 3.9-10.0mmol/L. We randomized 25 participants: mean(±SD) age 5.1±1.3 years, baseline HbA1c 55±9mmol/mol. Time in range was not significantly different between interventions (64±9% vs 65±9% for HCL with Fiasp vs IAsp; mean difference -0.33% [95% CI -2.13, 1.47; p=0.71]). There was no significant difference in time with glucose <3.9mmol/L. No post-randomization severe hypoglycemia or DKA events occurred. Use of Fiasp with CamAPS FX hybrid closed-loop demonstrated no significant difference in glycemic outcomes compared with IAsp in very young children with T1D. Clinical trials registration: NCT04759144.