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

AimsTo 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. MethodsIn 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. ResultsThe 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%. ConclusionsThe 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.