Predictors of inflammation in U.S. children aged 3-16 years.

BACKGROUND: Little is known about the correlates of low-grade inflammation in U.S. children.
PURPOSE: This study describes the factors associated with increased levels of C-reactive protein (CRP) in U.S. children and tests whether differences in CRP emerge in childhood because of socioeconomic factors.
METHODS: Data were analyzed in 2009 from 6004 children aged 3-16 years from the National Health and Nutrition Examination Survey, 1999-2004, a representative sample of the U.S. non-institutionalized population. Tobit regression models are used to evaluate associations between predictors, including BMI-for-age, skinfold body fat measures, chronic infections, environmental tobacco exposure, low birth weight, and sociodemographics and continuous high-sensitivity CRP in milligrams per liter.
RESULTS: CRP levels were higher in U.S. children with lower family income, and these differences were largely accounted for by differences in adiposity and recent illness. Mexican-American children had higher levels of CRP compared to both whites and blacks, but these differences were not explained by measured physical risk factors.
CONCLUSIONS: Increased adiposity is associated with higher CRP concentrations in U.S children aged 3-16 years, and both socioeconomic and racial/ethnic differences exist in systemic inflammation in U.S. children. Increased childhood obesity and low-grade inflammation may contribute to later life chronic disease risk.