T1D was diagnosed based on the following clinical features: positive for at least one of the following—glutamic acid decarboxylase antibody (GADA), protein tyrosine phosphatase antibody (IA-2A), islet cell antibody (ICA) and insulin autoantibody (IAA), and/or an FCP ≤ 200 pmol/L. Here, INS is linked to type 1 diabetes mellitus.