C-reactive protein and body mass index in children: Findings from the Third National Health and Nutrition Examination Survey, 1988-1994

Objectives: To examine the relationship between C-reactive protein (CRP) concentration and body mass index (BMI) in children, Study design: With the use of data from 5305 children aged 6 to 18 years in the Third National Health and Nutrition Examination Survey (1988 to 1994), a cross-sectional health survey, we examined whether CRP concentrations were elevated among overweight children. Results: Among children whose BMI was below the age- and sex-specific 15th percentile, 6.6% of boys and 10.7% of girls bad an elevated CRP concentration (>2.1 mg/L) compared with 24.2% of boys and 31.9% of girls whose BMI was greater than or equal to 95th percentile. After adjustment was done for age, ses, race or ethnicity, poverty, income ratio, high-density lipoprotein cholesterol concentration, white blood cell count, and history of chronic bronchitis, the adjusted odds of having an elevated CRP concentration were 2.20 (95% CI 1.30, 3.75) for children with a BMI of 85th to <95th percentile and 4.92 (95% CI 3.39, 7.15) for children with a BMI of 95th percentile compared with children who had a BMI of 15th to <85th percentile. The associations did not differ signifcantly by age, sex, or race or ethnicity. Conclusions: In a large representative sample of US children, CRP concentration was significantly elevated among children with a BMI 85th percentile, thus confirming previous findings of this association in children and extending previous research in adults to children, Excess body weight may be associated with a state of chronic low-grade inflammation in children.