The increasing onset of type 1 diabetes in children.

Objective: To identify trends in the recent onset of type 1 diabetes (T1D) in Colorado youth seen at the Barbara Davis Center (BDC) and compare these changes over time.

Study Design: A retrospective chart review was performed of patients ages 0-20 years at diagnosis of T1D and type 2 diabetes who were seen at the BDC, were living within Colorado at diagnosis, and were seen within 1 month of diagnosis between 1996 and 2010. The review included age of onset, sex, month and season of onset, islet autoantibodies, diabetes type, hemoglobin A1c level, and body mass index.

Results: Newly diagnosed youth with diabetes (n = 2841) were seen at the BDC between 1996 and 2010. Of these, 2686 (94.4%) had T1D. The number of newly diagnosed youth increased over the 15 years by 5.71% per year when adjusted for population (P < .0001). When analyzed in 5-year periods, the average number of new onset T1D cases, age-adjusted to the population, increased by 9.46% per year from 1996-2000 to 2001-2005. The increase was only 4.86% per year from 2001-2005 to 2006-2010. Islet autoimmune markers appeared to correlate with changes in T1D new onset cases.

Conclusion: T1D in youth increased significantly from the late 1990s-2005 and has increased at a lesser rate more recently. Data suggests that even though T1D has increased in all age groups, the greatest increase was in the 5-9 year age category.