IMPE Abstracts

Background: The incidence of type 1 diabetes has increased worldwide whereas a long-term trend for pediatric type 1 diabetes has remained elusive in Japan. Because a nationwide registry system for pediatric type 1 diabetes has not been established in Japan, it is difficult to simply extrapolate a national epidemiological study from the MAPChD data in Japan. The local registry systems in each prefecture or small-scale adjacent areas would be better for extracting the epidemiological data of T1D. For instance, in a recent study in Yamanashi Prefecture in Japan, Saito reported that a modest and non-significant increase was observed from 1986 to 2018 with an increasing annual rate of 1.16%; among them, the subpopulation aged 5–9 years had an annual significantly increased rate of 5.38% (CI: 2.34–8.35%).

Objective: This study aimed to investigate the incidence and secular trend of pediatric type 1 diabetes before and during the COVID-19 pandemic from 1999 to 2021 in Oita Prefecture, Japan.

Material and Method: We investigated the increase in the numbers of newly diagnosed patients with type 1 diabetes aged <15 years from1999 to 2021. We surveyed the medical information from hospitals in Oita and Oita Prefecture database in Japan.

Result: The incidence of type 1 diabetes in those aged <15 years increased annually by 5.3% in all children, especially by 8.1% in boys aged 10–14 years during the past 23 years. The average incidence rate of 3.9/100,000/year was almost consistent with the previous report from Asian countries. However, no significant change was found in the increasing incidence trend of type 1 diabetes before and during the COVID-19 pandemic. In this regard, 2 years of survey during COVID-19 pandemic might be too short to conclude the results. Especially, COVID-19 infection in children has been drastically increasing since the beginning of 2022, therefore further study after 2022 will be essential to clarify the direct impact of COVID-19 infection on the development of T1D in Japanese children.

Conclusion: The incidence of pediatric type 1 diabetes in Japan has significantly increased over the past 23 years, which is consistent with a worldwide trend.