Metabolic Risk Factors and Type 2 Diabetes Incidence in American Indian Children.

CONTEXT

Data are lacking on how metabolic risk factors during childhood affect the long-term risk of type 2 diabetes.

OBJECTIVES

Assess four metabolic risk factors as predictors of type 2 diabetes and determine whether the risk differs between younger and older children.

DESIGN

In a prospective cohort study conducted between 1965 and 2007, participants were followed for development of diabetes. Baseline measurements included body mass index (BMI), blood pressure, serum cholesterol, and 2-hour plasma glucose after an oral glucose tolerance test. Additional analyses divided subjects into two groups according to baseline age, 5–11 and 12–19 years.

SETTING

Gila River Indian Community in Arizona.

PARTICIPANTS

A total of 5532 nondiabetic Pima Indian children 5–19 years old.

RESULTS

A total of 1281 children developed diabetes (median follow-up, 12.4 years). Diabetes incidence was higher in overweight children (BMI ≥ 85th percentile) than in nonoverweight children. Nonoverweight children had the lowest risk of diabetes (20-year cumulative incidence, 9.5%), whereas overweight children with impaired glucose tolerance (2-hour glucose ≥ 140 mg/dL) had the highest (79.0%). The relative risk for children with metabolic abnormalities compared with their healthy counterparts was higher in younger children than in older children early in follow-up. BMI and 2-hour glucose were related to incident diabetes in multivariable models (predicted 15-year cumulative incidence for the highest vs lowest quartile was 3.9 and 1.8 times as high for BMI and 2-hour glucose, respectively; P < .001), whereas blood pressure and cholesterol were not.

CONCLUSIONS

BMI and impaired glucose tolerance in children are strong predictors of type 2 diabetes. Other components of the “metabolic syndrome” are not.