Background : The aim of the study was to analyze secular trends for in
crease of annual incidence rates of childhood insulin-dependent diabet
es in France between 1988 and 1995, Methods : The French Registry of i
ncidence of insulin-dependent diabetes in childhood was set up in 1988
in four regions covering more than 2 million subjects aged less than
20 yr. The degree of ascertainment was calculated as 96% between 1988-
1995 using data from the prospective catchment of the cases and medica
l data from the French Social Security. Results : Standardized annual
incidence rates were 7.17 and 9.28 per 100, 000, in 1988 and 1995 resp
ectively, assessing a 29% increase for age range at diagnosis 0-19 yr.
The trend for increase was statistically significant (r' = 0.95; p =
0.01). The incremental trend of incidence rates was calculated as 0.03
9 per year following a linear model for increase which proved to pl ed
ict calculated values nor significantly different from observed values
for annual total numbers of cases. This increase affected equally bot
h genders, and the younger age group at diagnosis (between 0 and 14 yr
.), but not the group 15-19 yr. of age at diagnosis. Conclusion : The
increase in incidence of IDDM was at the same order of magnitude as ob
served in Nordic countries where the overall incidence rate of IDDM in
childhood is at least three times as high as in France. It points tow
ards environmental factors playing a major role in the auto-immune pro
cess leading to beta cell destruction. This observation also strengthe
ns the need for research programs on the prevention of the clinical ph
ase of the disease. Such an observation should also supply Health Care
providers with important information for future management and organi
zation of IDDM care in childhood.