Seasonality of Month of Birth of Children (0-14 Years Old) with Type 1 Diabetes Mellitus in the District of Catania (Sicily)

Recent publications revealed that the seasonality in month of birth of children with type 1 diabetes mellitus (DM) was found to be different from that of the general population. This was also found in Sardinia, an island close to Sicily, as well as in other populations (The Netherlands, United Kingdom, Israel, Baden-Wuerttemberg and Slovakia)". We studied children with type 1 DM in the District of Catania (Sicily) with a yearly incidence of type 1 DM of 12.3/100,000 up to the age of 15. Between 1 January, 1989 and 31 December, 1998, 273 newly diagnosed patients below the age of 15 years were reported. Two independent sources of information were used: a) contact with all medical (n=29), pediatric (n=14) and endocrinological (n=2) services in the district; b) periodic review of personal identification cards issued by the National Health System to all patients with type 1 DM to allow free medical care and self-monitoring. The estimated completeness of ascertainment was 99.2% calculated by the capture-recapture method. In all patients the month of birth and month of onset of diabetes could be verified. The pattern of live births between 1979 and 1998 (n=280,871) was obtained from ISTAT (National Institute of Statistics). The pooled 20-year data for live births and the 10-year data of children with type 1 DM were divided into four seasons of the year and compared using Student's t-test. The results are