Aims/hypothesis. A rising incidence of Type I (insulin-dependent) diabetes
mellitus in different countries in Europe during the last decade has been r
ecently reported. However, in the early 1990s, Poland was reported to have
a stable low incidence of this disease. This study aimed to estimate the an
nual incidence of Type I diabetes in a north-eastern region of Poland (Bial
ystok region) and investigate if it is associated with age, sex, urban rura
l differences and the season of disease onset.
Methods. A register of patients with Type I diabetes using two independent
sets of data sources was established in 1994 as part of the EURODIAB TIGER
programme. The primary data sources were paediatric and internal medicine d
ivisions of the hospitals in the Bialystok province and the secondary were
outpatient diabetic clinics in the region. The degree of ascertainment was
98.5 % for the combinated data sources.
Results. We found a significant rising trend in the incidence of Type I dia
betes in children under 15 years of age (in 1998 the incidence was approxim
ately twice as high as in 1994). Increasing incidence rates were observed i
n the rural areas but not in urban populations. Seasonal variation in the i
ncidence was also found, with a peak in winter and nadir in summer.
Conclusions/interpretation. These results show that the north-eastern regio
n of Poland is an area with a moderate rather than a low risk of Type I dia
betes. Our observations confirm the important role of environmental and soc
io-economic factors or both in the pathogenesis of Type I diabetes.