Metformin Therapy for Overweight Adolescents With Type 1 Diabetes

Inclusion Criteria

• •1. Clinical diagnosis of presumed autoimmune type 1 diabetes (T1D) as indicated by age of diagnosis \<10 years or documented positive diabetes-related autoantibodies.
• •a. Note: For randomization, presence of at least one of the diabetes-related autoantibodies \[Insulin autoantibodies (IAA) at diagnosis prior to initiation of insulin, Islet cell antibodies (ICA), Anti-GAD (GAD65), Anti-IA2 (IA2), Zinc Transporter 8 (ZnT8)\] must be documented either from medical records or new laboratory measurement (IAA and ICA not measured by central lab) sent to central lab for participants who were ≥10 years old at diagnosis.
• •2. Age: 12 to \<20 years.
• •3. Duration of type 1 diabetes: ≥1 years.
• •4. Current insulin regimen involves either use of an insulin pump or multiple daily injections of insulin (at least 3 shots per day) for the last three months, with no plans to switch the modality of insulin administration during the next 6 months (e.g., injection user switching to a pump, pump user switching to injections).
• •5. Hemoglobin A1c: 7.5% - \<10.0% from point of care measurement or local lab on day of screening visit or within 1 month prior.
• •6. BMI: ≥85th percentile adjusted for age and sex .
• •7. Total daily dose of insulin: ≥0.8 units per kg per day.
• •8. Average of ≥3 Self-Monitoring Blood Glucose (SMBG) tests per day prior to initiating study and from download of study-provided blood glucose meter following screening visit.
• •9. Available for at least 6 months of follow-up, has home phone (or access to phone), and willing to be contacted by clinical site staff.
• •10. Expected to comply with protocol in investigator's judgment.