Association between plasma leptin/adiponectin ratio and insulin resistance indexes in prepubertal children

Objective: To assess the association between leptin/adiponectin ratio (LAR) and insulin resistance surrogates in prepubertal children. Subjects and methods: Study based on data from the Growth and Obesity Chilean Cohort Study (GOCS) involving 968 Chilean prepubertal children. Plasma insulin, leptin, and adiponectin were determined by immunoassays. Several common insulin resistance surrogates were calculated, including the homeostasis model assessment of insulin resistance (HOMA-IR), triglyceride/HDL cholesterol index, triglyceride-glucose (TyG) index, and the TyG index corrected for body mass index (BMI; TyG-BMI) and waist circumference (WC; TyG-WC). Associations among variables were assessed using multiple linear and logistic regression analysis. Results: There was a significant direct association between plasma leptin and LAR with BMI z-score but no association between plasma adiponectin and adiposity. After adjustments for sex and age, LAR was significantly associated with all insulin resistance surrogates (which were categorized using the 75th percentile as the cutoff point), with the TyG-WC index emerging as the surrogate with the highest magnitude of association (odds ratio [OR] 2.44, 95% confidence interval [CI] 2.05-2.9). After additional adjustment for BMI z-score, only the association between LAR and TyG-WC remained significant (OR 1.64, 95% CI 1.27-2.12). Conclusion: Plasma leptin and LAR were strongly associated with several common insulin resistance surrogates in prepubertal children, most notably with the TyG-WC index. Associations between LAR and insulin resistance indexes were mainly driven by the effect of plasma leptin, which is also directly associated with increased adiposity.