Incidence of type 1 diabetes among Polish children ages 0-14 years from 1989-2012

The incidence of pediatric type 1 diabetes mellitus (T1DM) in Poland is intermediate relative to the rest of the world. T1DM prevalence in the region of Silesia approximates national estimates for all of Poland. This epidemiologic study aimed to analyze the changes in incidence rates of T1DM among children ages 0-14 years from 1989 to 2012 in this region. Data collection methods for the registry followed EURODIAB criteria. To estimate overall population size, data from the Central and regional Statistical Office in Katowice were used. T1DM incidence rates/100,000 children ages 0-14 years/annum and their 95 % CI were calculated for all children and in age subgroups (0-4, 5-9, 10-14 years). For comparative analysis incidence rates were age and sex standardized to the population of Poland in 2005. For statistical analyses open source R Bioconductor software was used. During this 24-year period, 2,215 new cases (1,146 boys) were diagnosed. The standardized incidence rate rose about 7 % annually. The mean standardized incidence rates estimated in four 6-year time periods (1989-1994, 1995-2000, 2001-2006, 2007-2012) separately showed significant increases from 5.80/100,000/year (1989-1994) through 10.44/100,000/year (1995-2000) and 15.05/100,000/year (2001-2006) to 18.94/100,000/year (2007-2012). From 1989 to 2012, the greatest relative rise in annual incidence (/100,000/year) was among the very young: 2.58-14.00 (0-4 years); 4.96-19.43 (5-9 years); 8.84-22.15 (10-14 years). The highest average annual increment of the incidence rate was in the middle age subgroup (5-9 years). No significant sex difference was observed. The overall incidence rate increased 3.8 times, suggesting an epidemic of pediatric T1DM in Silesia, Poland. These temporal changes confirm that Poland currently has one of the highest incidence rates of pediatric T1DM in Europe.