Background: Soluble CD163 (sCD163) is shed from the cell surface into the circulation as a specific marker of macrophage activation. Macrophages are involved in low-grade inflammatory states such as obesity.
Objective and hypotheses: To investigate the relationships between circulating sCD163 and metabolic parameters in asymptomatic prepubertal children.
Method: A population of 236 school-aged Caucasian children (111 girls and 125 boys) aged 8±1 year (81 normal weight (BMI-SDS<1); 74 overweight (1≤IMC-SDS<2) and 81 obese (BMI-SDS≧2)) were enrolled in a cross-sectional study of obesity in primary care. Body mass index (BMI), waist circumference, fat mass (bioelectric impedance) and visceral fat mass (high-resolution ultrasonography) were measured. Fasting serum sCD163, glucose, insulin (and HOMA insulin resistance index), highly sensitive C-reactive protein (hs-CRP), gamma glutamyl transpeptidase (GGT) and lipids (triglycerides (TG) and HDL-cholesterol) were quantified.
Results: Circulating sCD163 concentrations were higher in overweight and obese children (P<0.0001). Increased circulating sCD163 was associated with a less favourable metabolic profile as judged by higher waist circumference, fat mass percentage, visceral fat, HOMA-IR, serum GGT and TG, and by lower HDL-cholesterol (all P<0.005 to P<0.0001). As expected, sCD163 associated also with hs-CRP (β=0.230, P=0.002). In multiple regression, circulating sCD163 levels were an independent predictor, together with age and visceral fat, of HOMA-IR (β=0.159, P=0.015; R2 model=0.171) and HDL-cholesterol/TG ratio (β=−0.151, P=0.035; R2 model=0.143).
Conclusion: We report for the first time on the association between circulating sCD163 and markers of a poorer metabolic profile, including insulin resistance and a proatherogenic lipid profile, in children. Childhood obesity may increase the risk of developing metabolic diseases later in life through chronic macrophage activation having deleterious effects on metabolism.
Funding: This study was supported by a grant from the Ministerio de Ciencia e Innovación, Instituto de Salud Carlos III (ISCIII), Madrid, Spain (PI13/01257), project co-financed by FEDER (Fondo Europeo de Desarrollo Regional).
01 - 03 Oct 2015
European Society for Paediatric Endocrinology