The Incidence of Type 1 Diabetes in the Age Group 0–39 Years Has Not Increased in Antwerp (Belgium) Between 1989 and 2000

• Published in: Diabetes care Vol. 25; no. 5; pp. 840 - 846
• Main Authors: Weets, Ilse, De Leeuw, Ivo H., Du Caju, Marc V.L., Rooman, Raoul, Keymeulen, Bart, Mathieu, Chantal, Rottiers, Raoul, Daubresse, Jean-Claude, Rocour-Brumioul, Danielle, Pipeleers, Daniel G., Gorus, Frans K.
• Format: Journal Article
• Language: English
• Published: American Diabetes Association 01-05-2002
• ISSN: 0149-5992; 1935-5548
• DOI: 10.2337/diacare.25.5.840

The Incidence of Type 1 Diabetes in the Age Group 0–39 Years Has Not Increased in Antwerp (Belgium) Between 1989 and 2000
Evidence for earlier disease manifestation
Ilse Weets , MD 1 ,
Ivo H. De Leeuw , MD, PHD 2 ,
Marc V.L. Du Caju , MD, PHD 2 ,
Raoul Rooman , MD 2 ,
Bart Keymeulen , MD, PHD 1 ,
Chantal Mathieu , MD, PHD 3 ,
Raoul Rottiers , MD 4 ,
Jean-Claude Daubresse , MD 5 ,
Danielle Rocour-Brumioul , MD 6 ,
Daniel G. Pipeleers , MD, PHD 1 ,
Frans K. Gorus , MD, PHD 1 and
The Belgian Diabetes Registry 7
1 Diabetes Research Center, Free University, Brussels, Belgium
2 Departments of Endocrinology and Pediatrics, University of Antwerp, Antwerp, Belgium
3 Department of Endocrinology, Catholic University, Leuven, Belgium
4 Department of Endocrinology, University of Ghent, Ghent, Belgium
5 Department of Endocrinology, Civil Hospital of Charleroi, Charleroi, Belgium
6 Department of Pediatric Endocrinology, CHR la Citadelle, Liège, Belgium
7 Belgian Diabetes Registry, Brussels, Belgium
Abstract
OBJECTIVE —A worldwide increase in the incidence of childhood type 1 diabetes has been observed. Because in various countries the majority
of new type 1 diabetic patients are diagnosed in adulthood, we investigated whether the rising incidence of this disorder
in children reflects a global increase in the incidence of diabetes or a shift toward earlier clinical presentation.
RESEARCH DESIGN AND METHODS —The incidence of type 1 diabetes presenting before age 40 years was prospectively measured in the Antwerp district over a
12-year period (1989–2000). The completeness of ascertainment was evaluated by the capture-recapture method. Trends in incidence
during the study period were analyzed by Poisson regression.
RESULTS —The incidence of type 1 diabetes diagnosed before age 40 years remained constant over the 12-year period, averaging 9.9 cases
per 100,000 individuals per year. The incidence was similar in both sexes under age 15 years, but a marked male excess was
noted for adult-onset disease, in particular after age 20 years, resulting in a male-to-female ratio of 0.9 under age 15 years
vs. 1.6 thereafter ( P = 0.001). During the 12-year observation period, there was a significant tendency toward increasing incidence under age 15
years at the expense of a decreasing incidence between ages 15 and 40 years ( P = 0.025). The annual increase in incidence averaged 1.8% under age 15 years and 5.0% under age 5 years ( P = 0.06).
CONCLUSIONS —Our results indicate that in Belgium, the increasing incidence of childhood type 1 diabetes—especially for children under
age 5 years—is not attributable to a global increase in disease incidence, but rather to earlier clinical manifestation. The
results suggest that an environmental factor may preferentially accelerate the subclinical disease process in young diabetes-prone
subjects.
BDR, Belgian Diabetes Registry
DIAMOND, DIAbetes MONDiale study
EURODIAB, EUROpe and DIABetes study
IAA, insulin autoantibody
IDA, Insulin-dependent Diabetes in young Adults study
GADA, glutamate decarboxylase antibody
RR, risk ratio
Footnotes
Address correspondence and reprint requests to Frans K. Gorus, MD, PhD, Diabetes Research Center, Vrije Universiteit Brussel,
Laarbeeklaan 103, B-1090 Brussels, Belgium. E-mail: frans.gorus{at}az.vub.ac.be .
Received for publication 31 October 2001 and accepted in revised form 29 January 2002.
A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.