Evaluation of Glycemic Changes During Exercise in Children With Type 1 Diabetes

Intervention and procedures:

a) The patients will first be assigned to standardized moderate-to-vigorous exercise for SG determination; b) similar exercise will then be repeated with preemptive adaptation of insulin dose (tailored on SG evolution during first exercise) for determination of potential influences on SG evolution.

Intervention Plan:

• At first visit (day [>18h] before exercise): setting of a Continuous Glucose Monitoring System
• At second visit: moderate-to-vigorous exercise with treadmill.
• At third visit (2 days after exercise): removal of CGMS
• At fourth visit (day [>18h] before fifth visit): setting of a Continuous Glucose Monitoring System
• At fifth visit: moderate exercise with treadmill, and insulin dose modification (basal rate, bolus, reduction, increase)
• At sixth visit (2 days after exercise): removal of CGMS
• Total number of visits: 6
• The exercises will be performed between 1 and 2 hours after breakfast or after lunch; the second exercise will be performed ≥2 weeks after the first exercise.

Controls:

• Moderate exercise with and without modification of insulin dose in MDI patients (by comparison with CSII patients). MDI patients will be matched to CSII patients according to gender, age, BMI (±0.5 z-score) and HbA1C levels (±1%) to exclude any bias in patient allocation.
• Moderate exercise without modification of insulin dose at first visit (by comparison with modification of insulin dose).

Inclusion criteria

• Diagnosis of T1D (according to the ISPAD 2011 guidelines)
• T1D outside of partial remission phase (defined according to the IDAA1C definition [Diabetes Care 2007], being equal to A1C (%) + [4 x insulin dose (units per kilogram per 24 h)] and at least > 2 years after T1D diagnosis (defined as the first day of insulin therapy)

Exclusion criteria

• Non-type 1 diabetes
• Severe neonatal asphyxia (defined as Apgar score 3 or less after 5 min), children born small for gestational age, chronic systemic disease, active malignancy, hypothyroidism, hypopituitarism, developmental delay, bladder dysfunction, obesity, carnitine deficiency, β-oxidation defect, cardiac malformations, dysrhythmia
• Intake of drugs interfering with insulin sensitivity (e.g. corticosteroids, GH).
• HbA1C >9.5% at the time of enrollment in the study.