Insulin resistance and endothelial function in children and adolescents

Aims: Insulin resistance (IR) impairs cellular response to insulin due to a dysfunction in glucose metabolism, associated with an increased cardiovascular risk. The aim of our study was to investigate the relationship among homeostasis model assessment index (HOMA index), endothelial function and vascular morphology in order to better stratify cardiovascular risk in children and adolescents.

Methods: A total of 150 children and adolescents (55 pre-pubertal, mean age 10.4 ± 3.1 years) were enrolled. Anthropometric [body mass index (BMI), waist circumference (WC)], laboratory [blood lipids, inflammatory markers, insulinemia, glycemia], HOMA index and ultrasound parameters [flow-mediated dilatation (FMD), common carotid intima-media thickness (cIMT) and antero-posterior diameter of infra-renal abdominal aorta (APAO)] were assessed.

Results: cIMT was positively related to age (r=0.274, p<0.01), BMI (r=0.318, p<0.01), WC (r=0.315, p<0.01) and triglycerides (r=0.230, p<0.01). APAO measurements showed a linear positive correlation with age (r=0.435, p<0.01), BMI (r=0.505, p<0.01), WC (r=0.487, p<0.01), triglycerides (r=0.280, p<0.01), C-reactive protein (r=0.209, p<0.05), fasting insulin (r=0.378, p<0.01) and HOMA index (r=0.345, p<0.01). FMD was inversely related to age (r=-0.251, p<0.01), rough BMI (r=-0.318, p<0.01), WC (r=-0.340, p<0.01), fasting insulin (r=-0.281, p<0.01) and HOMA index (r=-0.282, p<0.01). Multiple regression analysis found no influence of HOMA index on APAO and cIMT. HOMA index was an independent predictor for brachial artery FMD worsening after the statistical adjustment.

Conclusion: HOMA index increase induced a worsening in endothelial function since childhood.