Seasonality of birth in children (0-14 years) with diabetes mellitus type 1 in Baden-Wuerttemberg, Germany

The aim of the study was to find out whether children with diabetes type 1 in Baden-Wuerttemberg present a pattern of seasonality in their month of bi rth. A cohort of 1,184 children and adolescents (0-14 years) diagnosed as h aving diabetes between January 1(st), 1987 and June 30(th), 1997 were inclu ded in the study. Monthly and seasonal patterns of birth of patients with d iabetes were compared with the pattern of normal live births (n = 2,724,746 ) during the years 1972-1997 and the seasonality of onset of disease. Stati stical analysis was made using Student's t-test to compare the means betwee n four yearly seasons and single cosinor analysis for a period of 12 months . The children and adolescents with diabetes had a significantly different seasonality in month of birth pattern from that registered in the general p opulation, demonstrating fewer births during the months April-June and July -September. This seasonality pattern also differs from those registered in Israel, Sardinia and Slovenia, in which the population with diabetes type 1 had most births during these months.