Epidemiology, clinical aspects, and biology of IDDM patients under age 40 years. Comparison of data from Antwerp with complete ascertainment with data from Belgium with 40% ascertainment. The Belgian Diabetes Registry

Diabetes Care. 1997 Oct;20(10):1556-61. doi: 10.2337/diacare.20.10.1556.

Abstract

Objective: To compare the incidence rate of IDDM in the age-groups 0-14 and 15-39 years in Antwerp, Belgium, and to compare demographic, clinical, and biological data from Antwerp IDDM patients with 92% ascertainment with those from a larger Belgian patient group with 40% ascertainment.

Research design and methods: Incident cases of IDDM were reported by physicians of the Belgian Diabetes Registry and in Antwerp by several other sources. In Antwerp, completeness of ascertainment was calculated by the capture-recapture method. Demographic and clinical data were collected by questionnaire. Blood was sampled for HLA-DQ genotyping and, in new-inset patients, for autoantibodies.

Results: In Antwerp, the age- and sex-standardized IDDM incidence rates were similar in both age-groups (0-14 years: 11.8/100,000; 15-39 years: 8.9/100,000). The incidence rate decreased in girls above age 15 years (6.9/100,000; P = 0.003) but not in boys (11.0/100,000). Both in Antwerp and Belgium, IDDM was diagnosed more frequently in the 15-39 years age-group (60% of all cases) than under age 15 years, with a lower prevalence of acute symptoms, ketonuria, high-risk HLA-DQ genotype, and autoantibodies against insulin, islet cells, and IA-2, but with a higher prevalence of GAD65 autoantibodies.

Conclusions: In Antwerp, the incidence rate of IDDM under age 15 years is intermediately high compared with the rates in other European regions. It is similar in the 15-39 years age-group, but with a marked male predominance. Demographic, clinical, and biological data show the same age-dependent heterogeneity as the data collected nationwide, with 40% ascertainment indicating the representativeness of the latter.

Publication types

  • Comparative Study
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Autoantibodies / blood*
  • Belgium
  • Child
  • Child, Preschool
  • Demography
  • Diabetes Mellitus, Type 1 / blood*
  • Diabetes Mellitus, Type 1 / epidemiology*
  • Diabetes Mellitus, Type 1 / immunology
  • Female
  • Genotype
  • HLA-DQ Antigens / genetics
  • HLA-DQ alpha-Chains
  • HLA-DQ beta-Chains
  • Humans
  • Incidence
  • Infant
  • Insulin Antibodies / blood
  • Male
  • Registries*
  • Reproducibility of Results
  • Sex Factors
  • Surveys and Questionnaires
  • Urban Population

Substances

  • Autoantibodies
  • HLA-DQ Antigens
  • HLA-DQ alpha-Chains
  • HLA-DQ beta-Chains
  • HLA-DQA1 antigen
  • HLA-DQB1 antigen
  • Insulin Antibodies