Retinol-binding protein 4 and insulin resistance are related to body fat in primary and secondary schoolchildren: the Ouro Preto study.

摘要

Purpose: Evidence suggests that plasma retinol-binding protein 4 (RBP4) and insulin resistance are related to body fat (BF). We aimed to assess the relationship between RBP4 and insulin resistance with obesity in a mixed (skin color) cohort of the Brazilian population. Methods: A nested case-control study was conducted in 227 schoolchildren aged 7-14 years. Schoolchildren with a high BF percentage (% BF, >=30 for girls and >=25 for boys) were identified as the obese group (n=137), and those with lower values were identified as the non-obese group (n=90). Percentage of body fat (% BF) was determined by tetrapolar bioimpedance (Quantum II, RJL System), RBP4 by enzyme-linked immunosorbent assay (Immunology Consultants Laboratory), plasma fasting insulin by chemiluminescent immunoassay (AccessReg. Immunoassay System) and insulin resistance by the homeostasis model insulin resistance (IR_HOMA) index. Serum lipid profile and arterial blood pressure were evaluated. Results: The significant independent risk factors associated with obesity were as follows: male sex, increased serum LDL-C, RBP4 and IR_HOMA. Among children with higher RBP4, the association with obesity increased significantly (from 3.1 to 8.5) in the presence of insulin resistance, when compared to higher RBP4 and non-insulin resistance. Conclusion: IR_HOMA and RBP4 showed significant associations with obesity and traditional CVD risk factors. They might therefore be used as a marker for CVD risk and have clinical implications in the development of comorbidities associated with obesity.