Serum tumor necrosis factor-alpha levels and components of the metabolic syndrome in obese adolescents

Tumor necrosis factor-alpha (TNF-alpha) seems to be increased in obese subjects, suggesting its role as a proinflammatory cytokine to insulin resistance and metabolic abnormalities in obesity. The aim of this study was to evaluate the relationship between serum TNF-alpha, soluble TNF-alpha receptor 1 (sTNF-R1), TNF-alpha receptor 2 (sTNF-R2), and metabolic syndrome (MS) components and anthropometric indices in obese and non-obese adolescents. A cross-sectional study was performed on obese and non-obese adolescents. We studied 71 adolescents (age, 15 to 16 years old); 39 were obese (obese group; 14 males and 25 females) and 32 were non-obese adolescents (non-obese lean group; 12 males and 20 females). The body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were determined in each subject. The serum TNF-alpha, sTNF-R1, sTNF-R2, fasting plasma glucose (FPG), and lipid profile were also measured. The mean serum TNF-alpha, sTNF-R1, and sTNF-R2 were significantly higher in the obese than the non-obese group (TNF-alpha, 18.15 v 5.88 pg/mL, P < .001; sTNF-R1, 2.01 v 1.40 ng/mL, P < .001; sTNF-R2, 6.06 v 3.70 pg/mL, P < .001). The serum TNF-alpha concentrations were positively correlated with the BMI (TNF-alpha, r = 0.346, P < .05; sTNF-R1, r = 0.624, P < .001; sTNF-R2, r = 0.482, P < .001, respectively) and WC (TNF-alpha, r = 0.525, P < .05; sTNF-R1, r = 0.700, P < .001; sTNF-R2, r = 0.669, P < .001, respectively). The serum TNF-alpha was positively correlated with triglyceride (TG) and DBP, and negatively with high-density lipoprotein-cholesterol (HDLC). The sTNF-R1 and sTNF-R2 were correlated with TG and DBP, and TG, respectively. Obese compared with non-obese adolescents exhibited higher concentrations of TNF-alpha and its soluble receptors, and the higher TNF-alpha concentrations were associated with several components of MS in obese adolescents.