Childhood type 1 diabetes is defined by autoimmunity and insulinopenia. Etiopathogenic definition based on biochemical characteristics has recently replaced the clinical definition based on insulin requirement for treatment. The aim of this study was to describe biochemical and clinical characteristics of children with clinically diagnosed type 1 diabetes, hospitalized at the "Cristian Serban" Center in Buziaş.
Patients and methods: Fasting C peptide, HbA1c, islet cell autoantibodies (ICA) and antibodies against glutamic acid decarboxylase (GADA) were measured in 278 subjects aged (mean +/- SD; range) 15.1 +/- 4.8 (4-28) years, with a disease duration of 2.1 +/- 0.7 (1.1-3.1) years. GADA and ICA positivity was defined by values higher than the 95th percentile in 99 age-matched non-diabetic controls (0.4 units for ICA and 1.4 for GADA).
Results: As many as 66.2% of all patients had positive GADA and 10.1% had positive ICA. While 68.7% had at least one positive antibody, only 7.6% had both antibodies positive. As expected, most of the children (79.9%) had fasting C peptide values in the low range (<0.5 ng/ml), but 3 patients (1.1%) had biochemical signs of insulin resistance (C peptide concentrations >3 ng/ml). Two of the three insulin resistant children had positive GADA and one of them had positive ICA, therefore showing "mixed" features of both type 1 (autoimmunity) and type 2 diabetes (insulin resistance).
Conclusions: Childhood diabetes is now acknowledged to be a complex disorder with heterogeneity in its pathogenesis, clinical course and outcomes. While type 1 diabetes is the most frequent form of diabetes among Caucasian children, measurement of diabetes autoantibodies and C peptide is necessary to better define the types of diabetes in youth.