To analyze with the aid of CGM the blood sugar profiles of children receiving dual-wave versus standard bolus for dinner.

Primary objective To analyze with the aid of CGM the blood sugar profiles of children receiving dual-wave versus standard bolus for dinner.

Primary endpoint To compare time in range (TIR) during 2 weeks receiving dual-wave bolus versus standard bolus for dinner.

Trial design This is a 28-day long prospective randomized open-label single-center crossover clinical study with a 14-day long run-in phase.

Trial population A total of 30 subjects with type 1 diabetes.

Inclusion Criteria:

1. Children aged 7-18 years treated at the Children's Clinic of Tartu University Hospital for type1 diabetes.
2. Insulin pump and CGM initiated at least 3 months prior to the recruitment.
3. Estimated HbA1c based on the 14-days CGM report above 8.5%.
4. Daily insulin dose of more than 0.5 international units per kilogram.

Exclusion Criteria:

1. Subjects with known diabetes complications.
2. Elevated tissue transglutaminase IgA antibodies in the last two years.
3. Children who developed an acute viral infections during the week preceding the recruitment.

Exclusion criteria after the Run-in period

1. Basal insulin proportion > 55% of daily insulin dose.
2. Children with any symptoms of an infectious disease or acutely sick during the last two weeks.
3. Estimated HbA1c > 8.5% based on the 14-days CGM report.