Objective: Adult hypertension is independently associated with elevated C-reactive protein levels, after controlling for obesity and other cardiovascular risk factors. The objective of this study was to determine, with a nationally representative sample of children, whether the relationship between elevated blood pressure and C-reactive protein levels may be evident before adulthood.
Methods: Cross-sectional data for children 8 to 17 years of age who participated in the National Health and Nutrition Examination Survey between 1999 and 2004 were analyzed. Bivariate analyses compared children with C-reactive protein levels of >3 mg/L versus <or=3 mg/L with respect to blood pressure and other cardiovascular risk factors. Multivariate linear regression was used to evaluate the relationship between elevated blood pressure and C-reactive protein levels.
Results: Among 6112 children, 3% had systolic blood pressure of >or=95th percentile and 1.3% had diastolic blood pressure of >or=95th percentile. Children with C-reactive protein levels of >3 mg/L had higher systolic blood pressure, compared with children with C-reactive protein levels of <or=3 mg/L (109 vs 105 mm Hg). Obesity, high-density lipoprotein cholesterol levels of <40 mg/dL, and Hispanic ethnicity were independent predictors of elevated C-reactive protein levels. Diastolic blood pressure did not differ between groups. Linear regression analyses showed that systolic blood pressure of >or=95th percentile was independently associated with C-reactive protein levels in boys but not girls. Subset analyses according to race/ethnicity demonstrated that the independent association of elevated systolic blood pressure with C-reactive protein levels was largely limited to black boys.
Conclusions: These data indicate that there is interplay between race/ethnicity, elevated systolic blood pressure, obesity, and inflammation in children, a finding that has potential implications for disparities in cardiovascular disease later in life.