RELATIONSHIP BETWEEN LEPTIN-ADIPONECTIN RATIO AND INSULIN RESISTANCE IN OBESE SUBJECTS

Objective: Leptin and adiponectin are important hormones secreted from adipocytes that are involved in the regulation of energy homeostasis and might contribute to the link between obesity and insulin resistance. The aim of this study was to determine the relationships among various adipokine measures (leptin, adiponectin, and the ratio of leptin to adiponectin (L/A)), insulin resistance, and obesity. Material and Method: The study included 110 obese and 90 non-obese subjects. Fasting glucose, insulin, HDL cholesterol (HDL-C), triglycerides (TG), total cholesterol (TC), LDL cholesterol (LDL-C), leptin, adiponectin and anthropometric parameters were measured. Each subject's homeostasis model assessment of insulin resistance (HOMA-IR) index and leptin to adiponectin ratio (L/A) were calculated. Results: The L/A ratio was significantly correlated with HOMA-IR in both obese (r=0.25, p<0.01) and non-obese (r=0.68, p<0.01) subjects. In obese subjects, leptin and the L/A ratio were significantly correlated with body mass index (BMI) (p<0.01) and waist (p<0.01) and hip (p<0.01) circumferences and adiponectin was significantly correlated with HOMA-IR (r=-0.68, p<0.01). Best cut off value of L/A for BMI was found to be 0.78, sensitivity was 93.6% and specificity was 81.1% according to receiver operating characteristic (ROC) analysis. Conclusion: The results suggest that the L/A ratio might be a more sensitive and reliable indicator of insulin resistance in obese subjects than adiponectin or leptin concentrations.