Population-based survey of the prevalence of type 1 and type 2 diabetes in school children in Philadelphia

Background: Population-based (PB) registries of type 1 diabetes mellitus (T1DM) in children have been essential in determining the geographic, racial, and temporal patterns of the disease. There is a paucity of PB data on the prevalence of type 1 and type 2 diabetes (T2DM) in youth.

Methods: The prevalence of diabetes in children was determined using a PB survey of the 628 schools in Philadelphia. Data obtained included type of diabetes, date of birth, race, gender, date of diagnosis, diabetes treatment, and most recent height and weight.

Results: The survey was completed by nurses at 510 schools (81% of schools) representing 252,896 children (70% of children in Philadelphia). Prevalence (per 1000) was computed. The survey identified 492 cases (355 T1DM, 88 T2DM, 49 type unknown). The overall prevalence of T1DM was 1.58 (0.73 White, 0.56 African American, 0.50 Hispanic); of T2DM was 0.35 (0.03 White, 0.28 African American, 0.05 Hispanic). Mean age at diagnosis was 8.6 and 11.9 years for T1DM and T2DM, respectively. The prevalence of T1DM was higher in boys--T2DM was higher in girls. Of children with T2DM, 25% were treated with insulin. BMI was ≥95th percentile in 20% of children weighed (10% of T1DM, 57% of T2DM).

Conclusions: Although the Philadelphia Pediatric Diabetes Registry is the longest ongoing US registry of its kind, these are the first PB diabetes prevalence data of children in Philadelphia. PB studies in schools are able to capture children with diabetes who are diagnosed and treated in a variety of settings.