[Clinical heterogeneity of childhood diabetes in Baranya county]

Abstract

Introduction: Immune mediated type 1 diabetes is the most frequent form of childhood diabetes while type 2 and other forms are more rare in childhood in the Caucasian population. Differentiation of various diabetes subtypes has importance in the choice of treatment and prognosis.

Aims: The aim of the study was to describe clinical heterogeneity of childhood diabetes and to evaluate possibilities of phenotypical classification.

Methods: Two hundred twenty eight children (128 girls and 100 boys) with diabetes diagnosed at the Department of Pediatrics, University of Pécs, in the period of 1978-2000 were examined. Glycated hemoglobin levels, insulin requirement, body weight at diagnosis and association of type 1 diabetes with other disorders were analysed.

Results: Thirty one patients (13.6%) had permanently low (< 8%) glycated hemoglobin levels. Low glycated hemoglobin level associated with low insulin requirement (< 0.5 U/kg/day) was observed in three patients (1.4%) with 4 years of disease duration and in 2 patients (0.9%) during the whole disease course. These patients can be classified as non-classical type 1 diabetes cases. Obesity associated with less than 0.5 U/kg/day insulin requirement observed at least for two years from diagnosis was found in 2 cases (0.9%). These cases may be diagnosed as having childhood type 2 diabetes. The authors identified two diabetes patients with Down syndrome while MODY and transient neonatal diabetes were observed in one cases each. Diabetes associated conditions diagnosed in single cases each were as follows: thymus tumor, Duchenne muscular dystrophy, autoimmune polyglandular syndrome type 2, and T-cell lymphoma.

Conclusions: Childhood diabetes cases can be classified into several subgroups on clinical grounds, insulin requirement, and glycemic control. The data suggest that the prevalence of type 2 and non-classical type 1 diabetes is probably only a few percent among children with diabetes in Hungary. Due to phenotypic overlap between different forms of diabetes, measurement of beta-cell specific autoantibodies and C peptide levels can be recommended for etiologic classification.