Trends in type 1 diabetes incidence among children and adolescents in Bursa (2015-2022): impact of the COVID-19 pandemic and demographic insights

Objective: Type 1 diabetes (T1D) is a common, chronic, systemic disease in children and adolescents, and its incidence globally increases annually. This study aimed to determine the incidence, diagnostic features, and presentation characteristics of T1D in children and adolescents during the pandemic period in Bursa Province, Turkey. Method: This study included children under 18 with newly diagnosed T1D who consulted the Pediatric Endocrinology clinics of 3 tertiary hospitals in the city center of Bursa between January 1, 2015, and December 31, 2022. Nine hundred twenty-one pediatric patients were included in the study. The patients were divided into four groups according to age: Group 1, 0-4.9 years; Group 2, 5-9.9 years; Group 3, 10-14.9 years; and Group 4, 15-18 years. Results: Of the patients, 48.6% were female, and 51.4% were male. The median age at diagnosis was 9.23 years, with a significant age difference between genders. The highest incidence was observed in children aged 10-14.9 years. Moreover, two peaks were detected: 10-14.9 years in males and 5-9.9 years in females. The mean annual incidence was 3.8/100,000, peaking in 2017. During the COVID-19 pandemic, a temporary decline in diagnoses was noted, followed by an increase. Diabetic ketoacidosis (DKA) rates showed a significant rise over time, particularly in severe DKA cases during the pandemic. Conclusion: This study provides the first comprehensive analysis of the rate of newly diagnosed T1D in children and adolescents in Bursa Province. Additionally, the study evaluated age, gender, and seasonal patterns of initial diagnoses, with global trends constantly. The incidence of T1D and the rate and severity of DKA at presentation were affected during the COVID-19 pandemic, causing lockdowns and healthcare avoidance.