title: Incidence and prevalence of childhood-onset Type 1 diabetes in Japan: the T1D study.
abstract: A majority of children with Type 1 diabetes in Japan are registered with the government-subsidized Specified Pediatric Chronic Disease Treatment Research Projects (SPCDTRP). In this study, the incidence and prevalence of childhood-onset (< 15 years) Type 1 diabetes in Japan were estimated by drawing on SPCDTRP data.
  
  
  
  Data available for 2005-2012 from the SPCDTRP and Statistics Bureau, Ministry of Internal Affairs and Communications were used to estimate the incidence of Type 1 diabetes for 2005-2010, adjusted to cover those registered within 3 years of disease onset and stratified by sex, age at onset and period of onset.
  
  
  
  The incidence of Type 1 diabetes for 2005-2010 was 2.25/100,000 persons [95% confidence intervals (95% CI), 2.14-2.36] (boys: 1.91, 95% CI, 1.83-1.98; girls: 2.52, 95% CI, 2.34-2.69), with that for the age brackets 0-4, 5-9 and 10-14 years being 1.48 (95% CI, 1.29-1.66), 2.27 (95% CI, 2.08-2.47) and 3.00 (95% CI, 2.74-3.25), respectively. The onset of disease was shown to peak at age 13 among boys (3.28, 95% CI, 3.02-3.55) and at age 10 among girls (3.28, 95% CI, 3.02-3.55). The peak periods of disease onset were April/May and December. The number of children aged < 15 years with Type 1 diabetes for 2005-2012 was estimated to be 2326 (95% CI, 2202-2450) with the prevalence estimated as 13.53/100,000 persons (95% CI, 12.63-14.43).
  
  
  
  Study findings demonstrated no increase in the incidence of Type 1 diabetes, although suggesting, in agreement with earlier reports, that the onset of disease peaks in adolescence with a female predominance. In addition, the incidence of childhood-onset diabetes exhibited an annual bimodal pattern in this study.
authors.affiliation: Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine.
authors.forename: Y
authors.initials: Y
authors.lastname: Onda
authors.affiliation: Department of Pediatrics, Tokyo Women's Medical University Medical Center East, Tokyo.
authors.forename: S
authors.initials: S
authors.lastname: Sugihara
authors.affiliation: Department of Pediatrics, Hamamatsu University School of Medicine, Hamamatsu.
authors.forename: T
authors.initials: T
authors.lastname: Ogata
authors.affiliation: Department of Medical Subspecialties, National Center for Child Health and Development, Tokyo.
authors.forename: S
authors.initials: S
authors.lastname: Yokoya
authors.affiliation: Systematic Review Section, Department of Technology Assessment and Biostatistics, National Institute of Public Health, Saitama.
authors.forename: T
authors.initials: T
authors.lastname: Yokoyama
authors.affiliation: Jikei University School of Medicine, Tokyo, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Tajima
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology* / Q000208:ethnology; D005260:Female; D019456:Health Transition; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D012042:Registries; D012621:Seasons; D012737:Sex Factors; D013222:State Medicine