Performance of obesity indices for screening elevated blood pressure in pediatric population

BACKGROUND Hypertension is closely related with obesity in pediatric population. Obesity indices were used for screening elevated blood pressure (BP) in children and adolescents. The present study was to perform a meta-analysis to assess the performance of obesity indices, body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR), for identifying elevated BP in children and adolescents. METHODS Data sources were PubMed, EMBASE, Web of Science, Cochrane, and SCOPUS up to May 2016. Studies providing measures of diagnostic performance of obesity indices and using age-, sex-, and height-specific BP 95% as reference standard (the definition of United State Fourth Report) were included. We extracted available data on true-positive, false-positive, true-negative, and false-negative to construct a 2 × 2 contingency table and computed the pooled summary statistics for the sensitivities and specificities to estimate the diagnostic performance. RESULTS Nine eligible studies that evaluated 25,424 children and adolescents aged 6 to 18 years were included in the meta-analysis. The pooled sensitivities were 42% (BMI), 42% (WC), and 43% (WHtR). The pooled specificities were 80% (BMI), 75% (WC), and 77% (WHtR). The areas under the curve (AUCs) of obesity indices were 0.7780 (BMI), 0.7181 (WC), and 0.6697 (WHtR), respectively. In this meta-analysis, the BP measurements were based on 3 visits in only 1 study. The prevalence of hypertension may be overestimated in these studies. CONCLUSIONS The present meta-analysis showed that the performance of obesity indices for identifying elevated BP was poor. Our findings do not support the performance of WC and WHtR is superior to BMI to help identify children with elevated BP.