Increasing trend of type 1 diabetes incidence in the pediatric population of the Calabria region in 2019-2021

Background Although type 1 diabetes (T1D) represents one of the most common chronic diseases in pediatric age, few studies on the epidemiology of T1D exist globally and the exact prevalence and incidence rates of the disease are unknown. In many countries, including Italy, national registries are missing. Methods This study aims to assess T1D incidence in the pediatric population of the Calabria region (southern Italy) in the period 2019-2021. The secondary objective was to describe the main demographical, clinical and immunological features of incident cases. Case ascertainment and all clinical data were assessed by retrospectively reviewing the electronic medical records of children and adolescents diagnosed with diabetes at any Pediatric Diabetes Center belonging to the Rete Diabetologica Calabrese (Calabria Region Diabetes Network), from January 2019 to December 2021. The incidence of T1D was estimated for the entire region and was stratified according to age group (0-4 years, 5-9 years, and 10-14 years) and gender. Standardized incidence ratios for each province in the region were also calculated. Results The crude incidence of T1D was 20.6/100,000 person/years. Incidence rates were higher among females and children aged 5-9 years. The crude incidence of T1D was higher in the province of Reggio Calabria (26.5/100,000 person-years). The provinces of Crotone, Catanzaro, and Vibo Valentia showed significantly lower standardized incidence ratios. The annual incidence in the region progressively increased by 43% during the study period. Conclusions Our study revealed a relatively high incidence in the Calabria region. The marked increasing incidence trend over the past two years could be related to the global impact of the COVID-19 pandemic, but further long-scale population-based studies are needed to confirm these findings.