title: Long-term trends in the incidence of type 1 diabetes in Denmark: the seasonal variation changes over time.
abstract: There is a worldwide increase of type 1 diabetes mellitus (T1DM). In 1996, the Danish population-based registry was initiated including all newly diagnosed children aged 0-15 yr. This is the report of incidence and seasonal variation for the first 10 yr of the registry. The data was analyzed using Poisson's regression analysis. A total of 2166 children with diabetes were diagnosed before the age of 15 yr between 1996 and 2005. In this period, the annual increase in childhood T1DM was 3.43% (95% confidence interval: 1.91-4.97), which was unaffected by age and gender. Seasonal variation in incidence rates varied by year but not by age and gender. In conclusion, there is a steep increase in incidence of childhood T1DM in Denmark; the increase is comparable with the increase seen in other European countries. There is a significant seasonal variation that changes on a year-to-year basis. The observed variations in cadence rates may be associated with viral epidemics, sunshine exposure, or vitamin D levels and suggest further exploration of these relations.
authors.affiliation: Paediatric Department, Glostrup University Hospital, Glostrup, Denmark. js@dsbd.dk
authors.forename: Jannet
authors.initials: J
authors.lastname: Svensson
authors.forename: Annette
authors.initials: A
authors.lastname: Lyngaae-Jørgensen
authors.forename: Bendix
authors.initials: B
authors.lastname: Carstensen
authors.forename: Lars Bjarke
authors.initials: LB
authors.lastname: Simonsen
authors.forename: Henrik B
authors.initials: HB
authors.lastname: Mortensen
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003718:Denmark / Q000453:epidemiology; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology*; D005260:Female; D005544:Forecasting; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012042:Registries; D012621:Seasons; D013997:Time Factors