Rapidly rising incidence of Type 1 diabetes in children and adolescents aged 0-19 years in Zhejiang, China, 2007 to 2013

Aims To investigate the incidence rates and trends in Type 1 diabetes in children and adolescents aged 0–19 years in the registered Zhejiang population over the period 2007–2013 by age, sex and calendar year. Methods In total, 611 individuals with newly diagnosed Type 1 diabetes were identified from 30 districts in Zhejiang province over the study period. Annual incidence and 95% confidence intervals (CI) by age group and sex were calculated per 100 000 person‐years. Trends in diabetes incidence and the associations of age and sex with Type 1 diabetes were assessed using Poisson regression models. Results The mean annual age‐standardized incidence of diabetes was 2.02/100 000 person‐years (95% CI: 1.92–2.12), with an average annual increase of 12.0% (95% CI: 7.6–16.6%) over the study period. The risk for Type 1 diabetes in girls was estimated to be 1.25 (95% CI: 1.07–1.47) times higher than that in boys. Compared with those aged 0–4 years, the 5–9, 10–14 and 15–19 years age groups were at significantly greater risk, with adjusting incidence rate ratios of 3.54, 6.58 and 5.39, respectively. The mean age at diagnosis decreased significantly from 12.85 years in 2007 to 11.21 years in 2013. A steep rise in diabetes incidence was observed in the under 5 years age group, which showed the greatest increase at 33.61%. Conclusions The incidence of diabetes in Zhejiang was relatively low, although rapidly rising trends have been found in recent years, particularly in younger children. Further monitoring and research are urgently required to better understand possible environmental risk factors and formulate preventive strategies. What's new? The incidence of Type 1 diabetes in children and adolescents aged 0–19 years was relatively low between 2007 and 2013 in Zhejiang, China, with a mean annual age‐standardized incidence rate of 2.02/100 000 person‐years. However, a rapidly increasing trend was observed over the same period, with an average annual increase of 12.0% per year. The risk for Type 1 diabetes was estimated to be 1.25 times higher in girls than in boys. The age at diagnosis of Type 1 diabetes in children and adolescents has become younger, and a steep rise in diabetes incidence in the under 5 years age group was observed.