Introduction: collection of family history of diabetes mellitus (DM) is commonly performed when this illness is diagnosed in children. However the significance of gleaned information may differ depending on the affected family members.
Aim of the study: this study was performed in order to describe detailed familial history of DM in patients and to evaluate the impact of it on the natural course of childhood DM.
Material and methods: After exclusion of patients with confirmed monogenic basis of the disease or type 2 diabetes, the study group numbered 989 diabetic children. The data on detailed family history of DM among the first- and second- degree relatives, age at the onset of DM, recent percentage of glycated hemoglobin (HbA1c), presence of diabetes-related antibodies and the highest observed fasting c-peptide level were collected.
Results: Having siblings with DM was linked to early onset of diabetes in the study group (mean difference -2.83 95% confidence interval [cI] -4.24 to -1.42). Dominant mode of inheritance, particularly from the maternal side was significantly associated with diabetes onset at an older age. Children of diabetic mothers developed diabetes at a mean age of 10.83 in comparison to those without family history of DM - 8.75 years (p=0.0228). However, children whose mothers had any type of DM, had a significantly higher level of glycated hemoglobin than the others (8.34 vs 7.56%, p=0.0315). Additionally, a rising number of units of the family tree affected by any type of diabetes was associated with later onset of diabetes in children (p for trend = 0.0452).
Conclusion: Familial factors influence the natural course of childhood diabetes, but their contribution is not equal, showing more pronounced effects of maternal factors.