Objectives: Retinol-binding protein 4 (RBP4) and insulin resistance (IR) are clinical parameters associated with cardiometabolic diseases. The mediating and modifying roles of IR on children's susceptibility to cardiometabolic disorders are undetermined. This study investigated the mediating and modifying effects of the homeostatic model assessment of IR (HOMA-IR) on the relationship between the serum RBP4 level and clustering of pediatric cardiometabolic risk factors.
Methods: We assessed the diet, physical activity, cardiometabolic risk factors, and clinical parameters of 272 randomly selected adolescents from a large-scale cross-sectional study (n = 2727). Two HOMA-IRs (HOMA1-IR and HOMA2-IR) were used to evaluate the designated effects.
Results: Levels of serum RBP4 positively correlated with the levels of the 2 HOMA-based-IRs, and HOMA-IR correlated to all components of pediatric metabolic syndrome (MetS), the number of abnormal components, and a body-weight-weighted principal component score extracted from 12 cardiometabolic risk factors. Increased RBP4 levels had positive effects on waist circumference (WC), triglyceride, and the number of abnormal MetS components (0.310 cm, 1.384 μg/dL, and 0.021 item elevations, respectively), and the HOMA-IRs explained 17.7% to 21.9%, 11.8% to 27.6%, and 23.8% to 25.0% of these effects. The association of WC and the number of abnormal MetS components with the serum RBP4 level was enhanced by higher HOMA-IR (β for interaction, 0.13 and 0.01 for HOMA1-IR, and 0.32 and 0.02 for HOMA2-IR, respectively).
Conclusions: HOMA-IR is associated with the circulating RBP4 level and cardiometabolic risk factors in adolescents. Pediatric HOMA-IR may have mediating and modifying effects on the positive correlations between RBP4 and the clustering of MetS components.
Keywords: cardiometabolic risk factors; homeostatic model assessment; insulin resistance; pediatric metabolic syndrome; retinol-binding protein 4.
© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.