Cardio-metabolic risk screening among adolescents: understanding the utility of body mass index, waist circumference and waist to height ratio.

Background Few studies have assessed how well body mass index ( BMI), waist circumference ( WC), or waist to height ratio ( WtHR) perform in identifying cardio-metabolic risk among youth. Objective The objective of this study was to evaluate the utility of BMI and WC percentiles and WtHR to distinguish adolescents with and without cardio-metabolic risk. Methods A cross-sectional analysis of data from 6097 adolescents aged 10-13 years who participated in the HEALTHY study was conducted. Receiver operating characteristic curves determined the discriminatory ability of BMI and WC percentiles and WtHR. Results The discriminatory ability of BMI percentile was good (area under the curve [ AUC] ≥ 0.80) for elevated insulin and clustering of ≥3 risk factors, with optimal cut-points of 96 and 95, respectively. BMI percentile performed poor to fair ( AUC = 0.57-0.75) in identifying youth with the majority of individual risk factors examined (elevated glucose, total cholesterol, low-density lipoprotein, blood pressure, triglycerides and high-density lipoprotein). WC percentile and WtHR performed similarly to BMI percentile. Conclusions The current definition of obesity among US children performs well at identifying adolescents with elevated insulin and a clustering of ≥3 cardio-metabolic risk factors. Evidence does not support WC percentile or WtHR as superior screening tools compared with BMI percentile for identifying cardio-metabolic risk. [ABSTRACT FROM AUTHOR]