Receiver-operating characteristic analyses of body mass index, waist circumference and waist-to-hip ratio for obesity: Screening in young adults in central south of China

Background & aims Recent data suggest that current obesity diagnostic criterion based on body mass index (BMI) above 30 in Caucasians may not be appropriate for Asian populations. Our aim was to identify the usefulness of BMI, waist circumference (WC) and waist-to-hip ratio (WHR) in screening for obesity in an Asian population. Methods A cross-sectional sample of 1109 males and 879 females aged 20–45-yr were recruited. Height, weight, WC, hip circumference and percentage body fat (PBF) were measured in all subjects. Then receiver-operating characteristic analyses were used to evaluate the performances of the three anthropometric indices. Results BMI, WC and WHR showed strong positive correlation with PBF (r=0.47–0.75) in both males and females within both age groups. True-positive rates ranged from 82.4% to 94.1% and 68.8% to 86.3% in males and females, respectively. True-negative rates ranged from 64.1% to 84.7% and from 56.9% to 79.0%, respectively. The areas under the curves (AUCs) for WC and BMI were high (0.76–0.92) in both sexes and divided age groups (20–30-yr and 31–45-yr), and those for WHR were a little lower (0.74–0.88). Conclusions BMI and WC are two important predictors for obesity in Chinese, and WHR is an alternative.