Glycemic control in children and adolescent with type 1 diabetes remains inadequate, exposing them to the risk of vascular complications in adulthood.

One of the limiting factors is the daily number of self measurements of blood glucose required to optimize intensive insulin therapy.

Real Time Continuous Glucose Monitoring augmented by alarms (RT CGM) is a recent innovation. A randomized clinical study has shown its efficacy at short term (3 months). However, optimal clinical use of these devices requires rigorous assessment of their effectiveness on glycemic control, tolerance and acceptability in medium and long term.

Primary objective: To assess the long-term effectiveness of two strategies of use of RT CGM (continuous or discontinuous) on glycemic control compared to conventional blood glucose self-monitoring (SMBG).

Population: Children and adolescents with type 1 diabetes with inadequate glycemic control despite intensive insulin therapy.

Despite the development of intensive insulin therapy, glycemic control defined by glycated haemoglobin (HbA1c) < 7,5% remains inadequate in pediatric patients with type 1 diabetes.

Improvement of the metabolic control is limited by the daily number of self measurements of blood glucose required to adjust closely insulin therapy

Improving glycemic control is particularly important in type 1 children and adolescent, whose risk of vascular complications in adulthood is high, due to the duration of the disease and whose adherence to current strategies of blood glucose self-monitoring is limited.

Real Time Continuous Glucose Monitoring augmented by alarms (RT CGM) is a recent innovation. A randomized clinical study has shown improvement of HbA1c (≈ 1%) without increasing frequency of hypoglycaemia after continuous use for 3 months. Optimal clinical use of these new devices requires rigorous assessment of their effectiveness on glycemic control, tolerance and acceptability at medium and long term.

Primary objective: To assess the long-term effectiveness of two strategies of use of RT CGM on glycemic control compared to conventional blood glucose self-monitoring.

Secondary objectives: overall comparison of 2 strategies of continuous use of RT CGM vs conventional SMBG on HbA1c ; to evaluate their effectiveness on others parameters of glycemic control (hypoglycaemias, ketoacidosis, glycemic variability); to evaluate impact on glycemic control of different factors including percentage of effective time of wearing the sensor; to evaluate : skin tolerance, acceptability of the device; quality of life and satisfaction to the use of the device; and medico-economic impact of the use of the device.

Population: Type 1 diabetes children and adolescent with inadequate metabolic control despite intensive insulin therapy, randomized in 3 groups. After a period of 3 months of continuous measurement for all of them, the two strategies will be an intensive glucose monitoring by continuous measurement for 9 months (a total of 12 months) and an intermediate consisting of discontinuous measurement (40% of the time for 9 months), compared to conventional blood glucose self-monitoring.

The reduction in HbA1c of at least 0,6% requires 50 patients per group, and a total of 150 children.

Primary endpoint: change in the rate of HbA1c.

Secondary endpoints: frequency of acute metabolic events, non-severe or symptomatic hypoglycaemia; measure of glycemic variability; skin tolerance; number of sensor used and percentage of effective time of use of the device; satisfaction of the patients; quality of life and diabetes-related quality of life; choice of the patient (continuing or not to use the device) at the end of the study; medico-economic evaluation.

Benefits expected with this clinical trial: improvement of glycemic control and quality of life in children and adolescents with type 1 diabetes. Furthermore, study results would permit to defined optimal strategy of using RT CGM in paediatric population.

Inclusion Criteria:

• Age between 2 years and 17 years 11 months.
• Onset of type 1 diabetes ≥ 1 year.
• Centralized HPLC HbA1c ≥ 7.5% and < 11%.
• Intensive insulin therapy either by multiple daily injections ≥ 3 / day (rapid insulin analogue before 3 meal and 1 to 2 injections of basal insulin) or by continuous subcutaneous insulin infusion (pump).
• Followed in the centre for ≥ 3 months.
• Blood glucose self-monitoring ≥ 2/day.
• No significant change of regimen insulin therapy for at least 3 months.
• Patient receiving medical health insurance.
• Patient who has given his consent

Exclusion Criteria:

• Non type 1 diabetes(type 2 diabetes or diabetes whose evolution suggest other origin).
• Association with another pathology which, in the discretion of the investigator, could affect the monitoring or be disturbed by the participation in the study.
• Association with chronic treatment (steroids, growth hormone…) or chronic disease, including hypothyroidism and celiac disease, non stabilized for 3 months.
• Association with severe skin disease.
• Deafness, hearing or visual defect.