The association between insulin resistance and cytokines in adolescents with excess of adiposity

Background and aims: Increased adiposity has been directly associated with insulin resistance (IR), and cytokines released by adipose tissue seem to link adiposity to IR in youth. We used an antibody-based array to investigate the differential levels of serum cytokines according to insulin status in a cohort of overweight/obese and inactive adolescents and evaluated their potential associations with clinical and metabolic characteristics. Methods and results: We performed a cross-sectional data analysis from 122 adolescents (11-17 years of age). We assessed body composition, cardiometabolic risk factors, biochemical variables, and physical fitness. The concentration of 55 cytokines was quantified in blood samples. The homeostasis model assessment insulin resistance (HOMA-IR) and AST/ALT and TG/HDL ratios were calculated. IR adolescents as defined as HOMA-IR >2.5. The number of adolescents with IR in the study was 91 (66 % girls). In the IS group, after controlling for confounders, higher IL-15 levels were significantly associated with higher alanine aminotransferase levels and lower AST/ ALT ratio, respectively (Ps<0.05). In the same line, there were significantly higher alanine aminotransferase levels and lower AST/ALT ratio, respectively, with FGF-9 (Ps<0.05). Likewise, higher alanine aminotransferase levels were significantly associated positively with HGF (p=0.045). Additionally, leptin levels are associated with six adiposity indexes (i.e., fat mass/ height index, body fat, body mass index, android fat mass and gynoid fat mass) in overweight/ obese adolescents with IR (Ps<0.05). Conclusions: These data may provide novel insights into the pathogenic mechanisms underlying IR in youth, offering new targets for prevention.