title: A nine-year prospective study on the incidence of childhood type 1 diabetes mellitus in China.
abstract: To investigate the epidemiological characteristics of childhood type 1 diabetes mellitus in China, newly diagnosed cases of type 1 diabetes with an onset age under 15 years were retrospectively registered by 23 local centers in China following a standardized protocol on the basis of the nationwide registry established by the WHO DiaMond Project China Participating Center, Chinese Academy of Preventive Medicine (CAPM). A population of about 24 million children were covered in the defined areas. A two-sample capture-recapture method was used to estimate case ascertainment. Between 1988 and 1996, 903 diabetic cases were registered in 9 ethnic groups. The overall ascertainment corrected incidence rate (IR) was 0.59 per 100,000 person-year. The IR was 0.52/100,000 (95% CI: 0.50-0.54) for males and 0.66/100,000 (95% CI: 0.64-0.68) for females. The standardized ascertainment corrected IR by the national age-specific population in 1990 was 0.57 per 100,000 person-year. The incidence among various ethnic groups ranged from 0.25/100,000 to 3. 06/100,000. The IRs increased with northern latitude, and the IR of Han population was significantly higher in North China compared with South China (0.67 versus 0.53 per 100,000 respectively, P < 0.01). A correlation model of incidence and calendar time showed that the IR increased significantly between 1988 and 1996 (r = 0.86, P = 0.0027). The relative risk (RR) of type 1 diabetes mellitus for different age-groups estimated by a Poisson regression model showed that taking RR as 1.00 for age-group from 0 to 4 years, the RR for age-group from 5 to 9 year and from 10 to 14 year was 2.30 and 3.60 respectively. The standardized ascertainment corrected IR of childhood type 1 diabetes mellitus in China in much lower than in other countries. The geographic and ethnic variability of the incidence suggests that both genetic and environmental factors play a role in the development of childhood diabetes in China.
authors.affiliation: WHO DiaMond Project Chinese Participating Center, Chinese Academy of Preventive Medicine, Beijing, China.
authors.forename: X H
authors.initials: XH
authors.lastname: Li
authors.forename: T L
authors.initials: TL
authors.lastname: Li
authors.forename: Z
authors.initials: Z
authors.lastname: Yang
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Liu
authors.forename: Y D
authors.initials: YD
authors.lastname: Wei
authors.forename: S X
authors.initials: SX
authors.lastname: Jin
authors.forename: C
authors.initials: C
authors.lastname: Hong
authors.forename: R L
authors.initials: RL
authors.lastname: Qin
authors.forename: Y Q
authors.initials: YQ
authors.lastname: Li
authors.forename: J S
authors.initials: JS
authors.lastname: Dorman
authors.forename: R E
authors.initials: RE
authors.lastname: Laporte
authors.forename: K A
authors.initials: KA
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D011446:Prospective Studies; D012042:Registries; D012737:Sex Factors; D013997:Time Factors