Diagnostic accuracy of anthropometric indicators: Waist circumference, waistheight index and waist-hip ratio to identify overweight and childhood obesity

Abstract

INTRODUCTION: The identification of obesity in childhood is complicated because the height continues to increase and body composition is constantly changing, the diagnosis is currently done through growth patterns proposed by the WHO, however diverse anthropometric indicators have been proposed for equivalent detection. OBJECTIVE: To determinate the diagnostic accuracy of waist circumference (WC), waist-to-height ratio (WHtR) and waist-hip ratio (WHR) for identification of childhood overweight and obesity. MATERIAL AND METHODS: A cross-sectional and analytical study with a sample of 1001 schoolchildren (aged 9 to 11-years). Anthropometric measurements of weight, height, WC and hip circumference were obtained. BMI, WHtR and WHR were calculated. The correlation of anthropometric indexes vs BMI was assessed and a ROC curve analysis was performed taking as a study variable: WC, WHtR and WHR and as baseline the BMI percentiles (WHO, 2007). Sensitivity (Se), specificity (Sp), areas under the curve (AUC), positive and negative predictive values (PPV, NPV) of anthropometric indicators and cutoffs points that identify overweight and obesity were obtained. RESULT: The WC and WHtR showed strong positive correlation (r=0.75, 0.69, respectively; p < 0.001), but the correlation was weak for the WHR (r=0.23; p < 0.0001). WC and WHtR showed high ABC, Se, Sp, PPV and NPV for the identification of childhood-obesity. CONCLUSION: WC and WHtR has a high predictive power to identify childhood-obesity but not for overweight. The suggested cut-off points for the diagnosis of childhood-obesity between 9 and 11 years are 70cm for WC and 0.5 for ICT for both genders.