Epidemiology of coeliac disease in children and adolescents with type 1 diabetes: a 13-year population-based study using secondary data sources

Aims: To study the epidemiology of Coeliac Disease (CD) in the general paediatric population and among children with Type 1 Diabetes (T1D) in a population of Central Italy, and to assess the temporal trends of these two chronic conditions. Methods: A population-based longitudinal study on children aged < 15 was conducted using Healthcare Utilization Databases of the Marche Region, 2011–2023. Prevalent and incident cohorts of T1D and CD were identified using hospital discharges, drug prescriptions, and healthcare exemption databases. Prevalence ratios (PR), incidence rate ratios (IRR), temporal trends, and cumulative CD risk after T1D diagnosis were assessed with 95% confidence intervals (CI). Results: Overall 13-year period prevalences of T1D and CD were 1.65‰ and 5.28‰, respectively. CD prevalence among children with T1D was 97.7‰, 18-fold higher than in the general population (PR 18.6; 95%CI 14.3–24.0). CD incidence was 65 per 100,000 person-years in the general population and 2,410 per 100,000 person-years among children with newly diagnosed T1D (IRR 37.0; 95%CI 24.7–55.4). The six-year cumulative probability of developing CD in the T1D cohort was 10.3% (95%CI: 6.2%-14.3%). Conclusions: Children with T1D have a markedly increased risk of CD, particularly in the first years after diagnosis, supporting systematic CD screening in this high-risk population.