Seasonality of birth in children (0-14 years) with type 1 diabetes mellitus in Slovenia

The aim of this study was to find out whether there is seasonality of month of birth of children with diabetes in Slovenia and if so whether it differ s from that of the general population. A cohort of 849 children and adolesc ents (0-14 years) with type 1 diabetes mellitus born between 1956 and 1998 were included in the study. Monthly and seasonal patterns of birth of the p atients with diabetes were compared with the pattern of normal live births (n = 1,345,921) and the pattern of disease onset. Statistical analysis was made using Student's t-test to compare the means between the four seasons o f the year, and single cosinor analysis for a period of 12 months, The chil dren and adolescents with diabetes had a statistically significant differen t seasonality of month of birth compared to that of the general population, and an opposite pattern from the seasonality of month of onset of disease. The observations made are in accordance with observations made recently in other countries and support the hypothesis that a virus infection transmit ted by the mother to the fetus during the annual viral epidemic induces the autoimmune process in the pancreatic beta -cells in genetically susceptibl e individuals who will subsequently develop clinical diabetes during childh ood.