Waist circumference is related to low-grade inflammation in youth

Abstract

Objectives. To examine markers of infl ammation in 9- and 15-year-olds with high waist circumference and compare these with controls, and to examine the relationships between infl ammatory markers and cardiovascular disease (CVD) risk factors. Methods. Cross-sectional analysis of data from 2 299 Norwegian 9- and 15-year-olds participating in the “Physical activity among Norwegian Children Study”. In each sex and age group, the 10 participants with the highest waist circumference (HW) were selected (n 40) for analyses, and a random sample of 40 participants within the same groups were included as controls. Infl ammatory markers included C-reactive protein (CRP), leptin, adiponectin, plasminogen activator inhibitor-1 (PAI-1), tumor necrosis factor-α (TNF-α), hepatocyte growth factor (HGF), resistin and interleukin-6 (IL-6). The CVD risk factors included blood pressure, glucose, insulin, triglycerides and high density lipoprotein cholesterol. Results. HW participants had elevated levels of CRP (mean difference 1.50 mg/l; 95% confi dence interval [CI] 0.33 to 2.66), PAI-1 (mean difference 13.3 ng/ml; 95% CI 4.1 to 22.5) and HGF (mean difference 0.29 ng/ml; 95% CI 0.07 to 0.51) compared with controls. All CVD risk factors differed between the HW group and controls. The CVD risk factors were not associated with TNFα or IL-6, but CRP, HGF and PAI-1 were related to the metabolic risk score. Conclusions. Low grade systemic infl ammation is already present in youth with high waist circumference. CRP, HGF and PAI-1 may be related to the adverse overall metabolic risk profi le observed in these children and adolescents.