A comparison between body mass index and waist circumference for identifying continuous metabolic syndrome risk score components in Iranian school-aged children using a structural equation modeling approach: the CASPIAN-V study

Abstract

Purpose The purpose of this study was to investigate the association of anthropometric indices with continuous metabolic syndrome (cMetS) risk score components in a large population-based sample of children and adolescents. Methods This multi-centric study was performed on 3843 students aged 7-18 years who were selected by multistage, stratified cluster sampling method from 30 provinces of Iran. Demographic, anthropometric and biochemical factors were obtained and standardized residuals (z-scores) were calculated for MetS components. A structural equation modeling approach was applied to evaluate the relationships among the study variables and to implement the subsequent structural modeling. Results The mean age of the participants (52.3 boys) was 12.4 +/- 3.05 years. Standardized scores of body mass index (ZBMI) and waist circumference (ZWC) had a direct effect on standardized scores of mean arterial pressure (ZMAP) (0.23 and 0.24 in boys and 0.22 and 0.23 in girls, respectively) and triglyceride (ZTG) (0.07 and 0.04 in boys and 0.02 and 0.06 in girls, respectively), but the effect of ZWC was stronger than ZBMI on these variables. Age, socioeconomic status and sedentary behaviors showed a positive direct effect on ZWC (0.01, 0.05 and 0.07 in boys and 0.05, 0.08 and 0.002 in girls, respectively). These variables induced indirect effects on cMets risk score components through ZWC. Conclusion The magnitude of association between WC and continuous metabolic syndrome risk score components was higher compared to BMI in school-aged children, emphasizing on paying more attention to central obesity in childhood.