Developing waist-to-height ratio cut-offs to define overweight and obesity in children and adolescents

Abstract

AbstractObjectiveThe waist-to-height ratio (WHtR) assesses abdominal adiposity and has been proposed to be of greater value in predicting obesity-related cardiovascular health risks in children than BMI. The present study aims to develop WHtR cut-offs for overweight and obesity based on the 85th and 95th percentiles for the percentage body fat (%BF) in a cohort of children and adolescents.DesignWaist circumference (WC), height, triceps and subscapular skinfolds were used to calculate WHtR and %BF. Correlations between WHtR and %BF and WHtR/mid-abdominal skinfold were made. Receiver-operating characteristic (ROC) curve analysis was used to select WHtR cut-offs to define overweight and obesity. Subjects were grouped by WHtR cut-offs, and mean values for anthropometry, blood lipids and blood pressure (BP) variables were compared.SettingAustralian primary and secondary schools.SubjectsA total of 2773 male (M) and female (F) subjects of the 1985 Australian Health and Fitness Survey, aged 8–16 years.ResultsCorrelation coefficients between WHtR and %BF were M:r= 0·73, F:r= 0·60,P< 0·01 and WHtR/mid-abdominal skinfold were M:r= 0·78, F:r= 0·65,P< 0·01. WHtR of 0·46(M) and 0·45(F) best identified subjects with ≥85th percentile for %BF and 0·48(M) and 0·47(F) identified subjects with ≥95th percentile for %BF. When comparing the highest WHtR group to the lowest, both sexes had significantly higher means for weight, WC, %BF, TG (male subjects only), systolic BP (female subjects only) and lower means for HDL cholesterol (P< 0·05).ConclusionsWHtR is useful in clinical and population health as it identifies children with higher %BF at greater risk of developing weight-related CVD at an earlier age.