Validity of anthropometric indices in predicting high blood pressure risk factors in Iranian children and adolescents: CASPIAN-V study.

Anthropometric indices have been used as indicators for predicting hypertension (HTN) in children and adolescents but it is not clear which anthropometric measures are a better index for identifying elevated blood pressure (EBP) risk factors in pediatric population. Body mass index (BMI), waist circumference (WC), weight-height ratio (WHR), a body shape index (ABSI) and blood pressure were measured in 14 008 children and adolescents aged 7-18 years in a national school-aged survey CASPIN V. Hypertension (HTN) was defined according to the 2017 American Academy of Pediatrics guidelines, using the 95th percentile. The predictive power of anthropometric indices for HTN risk factors was examined using receiver operating characteristic (ROC) analyses. Multivariate logistic regression analysis was used to compare areas under ROC curves (AUCs) among the four anthropometric indices. BMI, WC, WHR, and ABSI were significantly higher in adolescents than in children. EBP was more prevalent in boys (7.2%) than girls (5.5%), whereas the prevalence of HTN was higher in girls (11.3%) than boys 10.4%. Prevalence odds ratio was around 2 for BMI, WC, and WHR with AUCs scores of nearly 0.6 to predict EBP in both children and adolescents of both sexes. Thus, the ability of BMI z-score, WC, WHR or ASBI to identify Iranian children and adolescents at higher risk of EBP was week. WC, WHR or ASBI in combination with BMI did not improve predictive power to identify subjects at higher risk of EBP.