Increasing incidence of type 1 diabetes in children aged 0-14 years in Harbin, China (1990-2000)

Abstract

Aims: (1) To determine the incidence of type 1 diabetes mellitus in children aged<15 years in Harbin, China and (2) to examine the trend in incidence over the period from 1990 to 2000.

Methods: Newly diagnosed cases of type 1 diabetes from 1990 to 2000 were identified among 1,286,154 Chinese children aged 0-14 years in Harbin. The primary source of case ascertainment was from hospital records and the secondary source from the health records of school clinics.

Results: One hundred and three cases were identified during 1990 and 2000. The annual incidence rate was 0.73 per 100,000 (95% CI: 0.59-0.88 per 100,000). No significant difference between males and females in the incidence of type 1 diabetes was observed. The incidence was significantly associated with age. With those aged<5 years as reference, the rate ratios were 2.06 and 4.1 for those aged 5-9 and 10-14 years, respectively. The incidence was higher in urban than in suburban regions, particularly among those aged 10-14 years. No significant seasonality was observed. There was a significant increasing trend in the incidence of type 1 diabetes during the period of 1990 and 2000, with an annual increase of 7.4% (95% CI: 1.6-13.5%).

Conclusions: There is a significantly increasing trend in the incidence of type 1 diabetes among children in Harbin. Increased number of cases has important implications for diabetes care providers. Understanding the etiology of this rise is critical for developing preventive measures to halt the trend.