Incidence and Severity of Type 1 Diabetes in Children Through the COVID-19 Pandemic in Chile

BACKGROUND AND OBJECTIVE: An increase in type 1 diabetes (T1D) incidence and severity was reported worldwide during the COVID-19 pandemic. The objective is to analyze whether this also occurred in the Chilean population aged less than 20 years. METHODS: A population-based analysis was performed with people aged less than 20 years with T1D from a nationwide registry (2007-2023). Annual and quarterly incidence rates were calculated. Incidence rate ratios were used to compare averages by sex, age groups, and season. A seasonal autoregressive integrated moving average (SARIMA) model was used to predict incidence rates from 2020, comparing them with actual rates. An individual pre-post analysis was also performed with patients aged less than 18 years with T1D from 3 tertiary centers (2016-2023). Diabetic ketoacidosis (DKA) proportions were compared with Fisher's exact test between 2016-2019 and 2020-2023. RESULTS: This study included 9583 individuals. T1D incidence increased from 7.4 cases in 2007 to 13.9 cases in a population of 100 000 aged less than 20 years in 2023. Average incidence rates were significantly higher in the 10- to 14-year age group and in winter. Actual quarterly rates were significantly higher than those SARIMA predicted from 2020 to 2021 and not significantly different from 2022 to 2023. Of 334 patients, 71% had DKA. A significant increase in DKA from 64.3% to 75.9% was found in 2020-2023 (P = .03). CONCLUSIONS: This study includes relevant data after 2021 and regarding severity. A significant increase in T1D incidence was found during the COVID-19 pandemic, paired with a higher severity at onset, returning to the prepandemic trend afterward. A causal relationship may be argued.