Incidence of Type 1 diabetes mellitus in children aged 0-14 in Japan. 1986-1990, including an analysis for seasonality of onset and month of birth: JDS study

Aims To detect the incidence of childhood Type 1 diabetes mellitus (DIM) (0-14 years) in Japan and to find out whether there is a seasonal pattern in the onset of disease and month of birth of children with diabetes. Methods Ascertained data for the period 1986-1990 could be collected in 35 out of 47 local government areas representing 69.4% of the childhood population (aged 0-14 years) of japan. Results A total of 1260 children with Type 1 DM were identified (738 girls, 522 boys). With age there was a progressive increase in incidence from 0.7 to 2.1/10(5) in boys and from 0.6 to 3.5/10(5) in girls. With the exception of 1987, when a coxsackie B3 virus epidemic was registered, no seasonal variation in the month of onset was observed, nor was a seasonal pattern of the month of birth registered in this cohort. Conclusions Compared to European countries, the USA and Israel, the Japanese cohort of children with diabetes presents the following differences: the incidence is much lower, there is a preponderance of girls and there is (with one exception) no seasonal pattern.