Interleukin-6, Tumor Necrosis Factor alpha and Metabolic Disorders in Youth

Abstract

Background : To compare Interleukin-6 (IL-6) and Tumor Necrosis Factor a (TNF alpha ) levels in obese and overweight youth to their normal weight counterparts. Furthermore, we compared IL-6 and TNF alpha levels in obese and overweight individuals with and without additional metabolic disorders such as Metabolic Syndrome (MS), Non Alcoholic Fatty Liver Disease (NAFLD) and prediabetes. Methods: All 54 consecutive obese children and adolescents with Body Mass Index (BMI) >= 95th centile and 50 overweight children and adolescents with 85th £ BMI < 95th were screened for MS, prediabetes and NAFLD. Serum IL-6 and TNF alpha were measured in all the participants and in 40 normal weight age-matched individuals (controls). Results: IL-6 levels were increased in obese children and adolescents compared to the controls (2.4 ± 1.9 vs 1.0 ± 0.5 pg/mL, P < 0.001) and to the overweight participants (1.5 ± 1.2 pg/mL, P < 0.014). IL-6 was also elevated in overweight compared to normal weight youth (P = 0.027) and in youth with MS compared to their counterparts without MS (2.9 ± 1.9 vs 1.7 ± 1.5 pg/mL, P = 0.013). TNF alpha levels were comparable between obese and normal weight (2.1 ± 1.2 vs 2.0 ± 0.6 pg/mL respectively, P = 0.805), overweight and normal weight (2.0 ± 1.0 pg/mL, P = 0.834), obese and overweight participants (P = 0.997). Obese and overweight individuals with NAFLD had elevated levels of TNF alpha compared to their counterparts with normal liver (2.7 ± 1.1 vs 1.0 ± 1.0 pg/mL, P = 0.005). Conclusions: Youth with excessive weight have elevated IL-6 levels, especially in the presence of MS. TNF alpha levels, although comparable between normal weight and excessive weight youth, are raised in overweight and obese individuals with NAFLD. J Endocrinol Metab. 2012;2(3):120-127 doi: https://doi.org/10.4021/jem111w