Trends in Incidence of Type 1 Diabetes Among Non-Hispanic White Youth in the U.S., 2002–2009

The SEARCH for Diabetes in Youth Study prospectively identified youth aged <20 years with physician-diagnosed diabetes. Annual type 1 diabetes (T1D) incidence per 100,000 person-years (95% CI) overall, by age-group, and by sex were calculated for at-risk non-Hispanic white (NHW) youth from 2002 through 2009. Joinpoint and Poisson regression models were used to test for temporal trends. The age- and sex-adjusted incidence of T1D increased from 24.4/100,000 (95% CI 23.9-24.8) in 2002 to 27.4/100,000 (26.9-27.9) in 2009 (P for trend = 0.0008). The relative annual increase in T1D incidence was 2.72% (1.18-4.28) per year; 2.84% (1.12-4.58) per year for males and 2.57% (0.68-4.51) per year for females. After adjustment for sex, significant increases were found for youth aged 5-9 years (P = 0.0023), 10-14 years (P = 0.0008), and 15-19 years (P = 0.004) but not among 0-4-year-olds (P = 0.1862). Mean age at diagnosis did not change. The SEARCH study demonstrated a significant increase in the incidence of T1D among NHW youth from 2002 through 2009 overall and in all but the youngest age-group. Continued surveillance of T1D in U.S. youth to identify future trends in T1D incidence and to plan for health care delivery is warranted.