Waist-to-Height Ratio as an Index for Cardiometabolic Risk in Adolescents: Results from the 1998-2008 KNHANES

Purpose: To describe the relationship between the waist-to-height ratio (WHtR) and cardiometabolic risk factors (CMRFs) and to evaluate the validity of WHtR in identifying adolescents with metabolic syndrome. Materials and Methods: We analyzed data from a pooled population of 4068 adolescents aged 10-19 years from the Korean National Health and Nutrition Examination Surveys conducted between 1998 and 2008. Overweight individuals were defined by body mass index (BMI) >= 85th percentile. Those with at least 2 CMRFs among hypertension, hyperglycemia, hypertriglyceridemia, and decreased high-density lipoprotein cholesterol (HDL-C) were classified as having multiple CMRFs. Results: WHtR was significantly related to systolic blood pressure, HDL-C, and triglycerides in both non-overweight and overweight adolescents (all p<0.01). Among overweight adolescents, the area under the curve (AUC) for WHtR in identifying multiple CMRFs was significantly greater than that for BMI (p=0.014). Metabolic syndrome was more common in overweight adolescents with a WHtR of >= 0.5 than in those with a WHtR of <0.5 (p<0.001). In non-overweight adolescents, the prevalences of multiple CMRFs (p=0.001) and metabolic syndrome (p<0.001) were higher in those with a WHtR of >= 0.5 than in those with a WHtR of <0.5. Among those without central obesity, the prevalence of multiple CMRFs was higher in those with a WHtR of >= 0.5 than in those with a WHtR of <0.5 (p=0.021). Conclusion: WHtR is a simple and valid index for identifying adolescents with increased cardiometabolic risk and is related to CMRFs even in non-overweight adolescents. In adolescents already screened via BMI and waist circumference (WC), WHtR seems to be of additional help in discriminating those at higher cardiometabolic risk.