Incidence of type 1 diabetes in Gansu Province, Northwest China from 2018 to 2022: a multicenter, hospitalization-based study

Objective: To survey the epidemiology of type 1 diabetes in all age groups living in the Gansu Province, China during 2018-2022.

Methods: Using the data from the Gansu Province Health Commission Information Center and medical records, the crude incidence and 95%CI were calculated by region, age group, and sex assuming a Poisson distribution. The incidence differences were evaluated using the χ2 test. Spearman correlation was used to analyze the relation between latitude and incidence. The seasonality was analyzed using concentration, seasonal index and circular distribution method.

Results: 1393 cases of newly diagnosed type 1 diabetes were ascertained. The crude incidence of type 1 diabetes per 100,000 person-years in all individuals in Gansu Province was 1.09(95% confidence interval 1.03 to 1.15). The estimated incidence per 100,000 person-years by age group was 1.39 (95%CI:1.24-1.54) for 0-14 years, 3.58 (95%CI:3.33-3.83) for 15-29 years, 0.33(95%CI:0.29-0.37) for ≥ 30 years, with a peak in age group 15-19 years. There was a difference between males and females. Incidence of type 1 diabetes in Gansu Province was strongly correlated with latitude among children aged 0-29 years, and all age groups, but such correlation was not observed in adults aged ≥ 30 years. The seasonality of the type 1 diabetes is not obvious.

Conclusion: The incidence of type 1 diabetes was relatively lower from 2018 to 2022 in Gansu Province, with variations across different regions and a positive correlation with latitude observed in all age groups. The incidence peak was noted in the 15-19 years group, and the incidence among males was higher than in females in all age groups. There was no significant seasonal variation in the incidence of type 1 diabetes.