Waist-to-height Ratio Index or the Prediction of Overweight in Children

OBJECTIVE To identify a low-cost abdominal adiposity index that has a higher accuracy in predicting excess weight in children aged four to seven years old. METHODS A cross-sectional study with a sample of 257 children aged 4 to 7 years old. Indicators of abdominal adiposity assessed were: waist circumference (WC), waist-to-height ratio (WHR) and central fat percentage (measured by dual energy X-ray absorptiometry - DEXA). Overweight children were classified using body mass index by age (BMI/age). In the analysis, the prevalence ratio (PR) using Poisson regression with a robust variance was estimated, and a receiver operating characteristic (ROC) curve was built, with a statistical significance of p<0.05. RESULTS The prevalence of overweight children was 24.9% and a higher median of all abdominal adiposity indicators was observed in the overweight group. Children with increased values of WC (PR=4.1; 95%CI 2.86-5.86), WHR (PR=5.76; 95%CI 4.14-8.02) and a central fat percentage (PR=2.48; 95%CI 1.65-3.73) had a higher prevalence of being overweight. Using the ROC curve analysis, the WHR index showed a higher area under the curve, when compared to the WC and to the central fat percentage estimated by DEXA for predicting the classification of being overweight. CONCLUSIONS Given the results, WHR is suggested for the screening of overweight children.