Increased Leptin/Adiponectin Ratio and Free Leptin Index Are Markers of Insulin Resistance in Obese Girls during Pubertal Development

Abstract

Background: Modifications in body fat in obese patients during puberty determine changes in adipokines that affect insulin sensitivity. Aims: We hypothesized that the leptin/adiponectin (L/A) ratio and free leptin index (FLI) are good markers of insulin resistance (IR) and total body fat (TBF) during pubertal development. Methods: A prospective study of 32 obese girls (OG) and age-matched control girls (CG) was performed. OG were divided into those that maintained a weight loss (WL) of >1 SD of initial body mass index (BMI) (WL group, n = 25) and those without WL (NWL group, n = 7). Oral glucose tolerance tests (OGTT) were performed to evaluate IR. Correlations of adipokines, L/A, and FLI with BMI, waist circumference, percentage of TBF (%TBF) and IR were performed over pubertal development. Results: The L/A ratio and FLI were increased in OG at baseline. Both indexes decreased in the WL group as puberty progressed, with no change in CG or NWL. In the WL group, a correlation between L/A and FLI with OGTT and %TBF, and L/A and homeostasis model assessment (HOMA) was found throughout the study. Conclusion: The L/A ratio and FLI are good markers to follow changes in IR and %TBF after WL during puberty. Insulin more accurately reflects the changes in IR than HOMA.