This trial is conducted in Europe. This is a single-centre, retrospective trial aiming at comparing the antibody levels in children and adolescents.

Inclusion Criteria:

• Informed consent obtained before any trial-related activities
• Any subjects at onset of Type 1 Diabetes
• Treatment with either Insulin Aspart and Soluble Human Insulin or Soluble Human Insulin and Isophane Human Insulin / Mixtard® for at least 9 months from the time of diagnosis of diabetes

Exclusion Criteria:

• Treatment with immunosuppressive agents
• For the Insulin Aspart + Isophane Human Insulin: Treatment with insulin analogues other than Insulin Aspart or treatment with fast acting human insulin for a period of 7 days or more during the treatment period
• For the Soluble Human Insulin and Isophane Human Insulin group: Treatment with insulin analogues
• Other diseases influencing immune response
• Unable or unwilling to provide consent