ABSTRACT
INTRODUCTION: The incidence of type 1 diabetes shows wide geographical variability and heterogeneity. The aim of this study was to determine the incidence and prevalence of type 1 diabetes in children and adolescents ages less than 15 years in the different provinces of Castilla-León. MATERIAL AND METHODS: To determine incidence, all new cases of type 1 diabetes with onset under 15 years of age in 2003-2004 were obtained. Incidence was expressed as the crude value with the corresponding confidence interval and as standardized incidence. The capture-recapture method was used to calculate the completeness of ascertainment. To determine prevalence, all cases of type 1 diabetes in persons ages less than 15 years at 31 December 2004 were obtained. RESULTS: Incidence showed wide variability among the different provinces of Castilla-León. The highest values were found in Segovia (38.77/100,000/year), Valladolid (32.07/100,000/ year) and Avila (23.21/100,000/year) and the lowest in Zamora (8.14/100,000/year). Incidences were highest in the 5-9 years age group in all provinces except Burgos. Prevalence was highest in Segovia (1.54/1,000), Valladolid (1.41/1,000), Avila (1.38/1,000) and Zamora (1.32/1,000) and lowest in Burgos (0.91/1,000). CONCLUSIONS: Castilla-León seems to have one of the highest incidences of type 1 diabetes in Spain; several of its provinces have values similar to those in Northern Europe.