Chemerin serum levels are associated with parameters of obesity and vascular inflammation in children

Objective: The new adipokine chemerin has been shown to play a role in adipocyte differentiation and is associated with parameters of obesity and metabolic syndrome in adults. In this study, we aimed to analyze chemerin serum levels and their association to measures of obesity and early-onset metabolic and vascular sequelae in children.

Methods and results: Serum levels of chemerin were quantified by ELISA in 69 lean and 105 obese children of the Leipzig Atherobesity childhood cohort. Associations of chemerin with detailed metabolic and cardiovascular parameters were assessed. We identified highly significant associations of chemerin serum concentrations with obesity-related parameters, such as BMI SDS (r=0.57, p<0.001), leptin (r=0.39, p<0.001), and skinfold thickness (r=0.54, p<0.001). Mean serum chemerin concentrations were significantly higher in obese compared to lean children (117.82±26.35ng/mL vs. 89.75±16.08ng/mL; p<0.001). Moreover, chemerin levels were associated with parameters of glucose and insulin metabolism, as fasting plasma insulin levels (r=-0.38, p<0.001) and Matsuda ISI (r=-0.40, p<0.001). Children with impaired insulin sensitivity had higher serum chemerin levels compared to children with normal insulin sensitivity (118.21±23.41ng/mL and 99.73±23.99ng/mL, p<0.001). However, after adjustment for BMI SDS and age in partial correlation analyses, all significant correlations of chemerin with metabolic parameters were lost indicating an underlying association with obesity and fat mass. Furthermore, we identified significant BMI-independent correlations of chemerin serum levels with general measures of inflammation, as hsCRP (r=0.50, p<0.001) and white blood cell count (r=0.30, p<0.001), as well as the parameters of endothelial activation, ICAM-1 (r=0.33, p<0.001) and E-selectin (r=0.30, p<0.001). Multiple regression analyses revealed that chemerin is the strongest predictor of ICAM-1 and E-selectin serum concentrations independent of BMI SDS, age, sex, pubertal stage, and hsCRP levels of the subject.

Conclusions: Similarly to adults, chemerin serum levels are associated with obesity and metabolic syndrome in children. Moreover, in children chemerin is strongly associated with parameters of inflammation and endothelial activation suggesting a potential role of chemerin in obesity-related vascular inflammation as an early stage of atherogenesis.