Introduction: The epidemiology of childhood type 1 diabetes (DM1) allows to understand the genetics and enviromental factors involve in one of the most prevalent chronic disease in children. The unification of methodological recommendations has allowed to detect new research lines.
Method: We present an observational study of population under 13 years old and DM1 in Extremadura (19962011). The aim was to examine secular trends in the incidence of DM1 in children, by annual percentage change (APC).
Results: A total of 577 cases were diagnosed (case ascertainment: 98.9%). Age-and sex-adjusted incidence was 22.7cases/100 000 (95% CI 13.531.9) and the peak of incidence was in 2005 (30.7). The incidence by periods (4 years) was not significantly different. The APC was analyzed by Jointpoin Regression highlighting one significant change in the term trend: the incidence increased annually by 6.6% until 2004, followed by a plateau until the end of 2011 (P<0.01). The same pattern was presented in the male group (P 0.012) but not in women group, in which there was not change in the annual growing trend. Analysis by age: the group of 1014 years old presented an acceleration of 7% annually until 2005, and a deceleration period until 2011 (P 0.025). There were no changes in the trends in other groups of age.
Conclusions: i) The analysis of annual percentage change should be included in the recommendations of the international epidemiological DM1 studies in order to avoid mistakes in the interpretation of the results. ii) We report the first evidence of the reversed trend in the incidence of DM1 in Southern Europe. Two other studies published similar findings, in Finland and Sweden, in 2005. iii) Even more, according these results, the environmental factors related could specifically affect the group of men aged 1014 years.
20 - 22 Sep 2014
European Society for Paediatric Endocrinology