High levels of interleukin-6 and triglycerides and low levels of soluble leptin receptors as risk factors for leptin resistance in obese adolescents

Abstract

Introduction: Obesity is a nutritional disorder that can affect all ages, including teenagers. Obesity can affect gut microbiota and cause increased intestinal permeability. This process leads to interleukin-6 and TNF-α production which can increase leptin levels. The soluble leptin receptor (sLR) is a leptin receptor in the plasma that transports leptin to the hypothalamus. Low sLR numbers are associated with high leptin levels in obesity. Obesity in hyperleptinemia conditions indicates leptin resistance (defects in leptin receptors) which causes hyperphagia and reduces energy expenditure. This study was conducted to prove high TG and IL-6 serum levels and low sLR levels in obese adolescents who have a higher risk of developing leptin resistance than normal adolescents. Methods: This research is a case-control study. The subjects underwent an assessment including food recall, anthropometric status, and lipid profile. The food recall assessment was obtained by means of a questionnaire given to parents. Blood sampling and laboratory examination are carried out by the Prodia® Clinical Laboratory. Data analysis was performed by computer, using the Independent t-test, Mann-Whitney test. Chi-Square test, and analysis of the ROC curve. Results: ROC curve analysis obtained the optimal cut points for TG and IL-6 levels, respectively 101.5 mg/dL (sensitivity 82.1%, specificity 89.7%) and 11.95 pg/mL (sensitivity 84.6%, specificity of 80%), with area under the curve (AUC) values of 0.96 and 0.89, respectively. ROC curve analysis obtained the optimal cut point for sLR levels of 19.3 ng/mL (sensitivity 64.1%, specificity 71.8%) with an AUC value of 0.77. Multivariate analysis using logistic regression found a significant relationship between TG and IL-6 levels on the incidence of hyperleptinemia. Conclusion: This study reinforces the theory of chronic low-grade inflammation and proved that inflammation and high TG levels play a role in hyperleptinemia in obese adolescents.