Obesity associated inflammation in African American adolescents and adults

C-reactive protein (CRP) is related to adiposity and metabolic risk and predicts events in adults. The objective was to determine if relationships between adiposity and CRP have similar magnitudes in adolescents as adults.

Healthy African Americans (484 adults and 282 adolescents) were recruited from similar environments. In both cohorts, measurements included anthropometrics, blood pressure (BP), metabolic risk factors and inflammatory markers. After stratification by high-sensitivity CRP (hsCRP: ≤1, 1-≤3, >3 mg/dL), adults and adolescents were compared with regard to body mass index (BMI; kg/m), waist circumference (WC; cm), BP and other risk factors. hsCRP was regressed on BMI and WC with covariates including cohort, age, sex, BP, insulin resistance, smoking, alcohol and other biomarkers. Interaction terms and a subset of the covariates were subject to a supervised variable selection procedure for a final model. Skewed variables were log transformed and summarized by geometric means (GMs) with 1st and 3rd quartiles (Q1, Q3).

Among adolescents (16.3%) and adults (34.1%) having high hsCRP(>3 mg/dL), BMI was distributed similarly (GM = 36.4 [32.7, 43.1] and GM = 34.7 [28.8, 40.8], respectively) as was WC (GM = 104.2 [93.0, 119.0] and GM = 104.9 [93.0, 117.2], respectively). In an adjusted regression model, for a given BMI, elevated WC was associated with elevated hsCRP (P = 0.02). Although elevated BMI was significantly associated with elevated hsCRP, the relationship was stronger among adolescents (interaction P = 0.04).

These findings demonstrate that, in African Americans, obesity is associated with inflammation and adverse changes in metabolic parameters among both adolescents and young adults.