Body shape indices and cardiometabolic risk in adolescents

BACKGROUND: "A Body Shape Index" (ABSI) is a recently proposed index that standardizes waist circumference for body mass index (BMI) and height using the scaling exponents 2/3 and 1/2, respectively, estimated from adults. Incidentally, waist-to-height ratio has been suggested as an indicator of cardiometabolic risk in adolescents. AIMS: This study aims to estimate the scaling exponents for standardizing waist circumference for BMI and height in Chinese adolescents and to estimate and compare the ability of various body shape indices in predicting cardiometabolic risk in adolescents. SUBJECTS AND METHODS: Participants aged 10-17 years in the 2009 China Health and Nutrition Survey were analysed. RESULTS: The appropriate scaling exponents for standardizing waist circumference for BMI and height in this adolescent sample were 0.45 and 0.55, respectively. A new ABSI-adolescents was defined accordingly. Ignoring the age dependence in the scaling exponents would lead to confounded associations. The ABSI-adolescents and the waist-to-height ratio were more associated with glycated haemoglobin and pre-diabetes, but not blood pressure, than the BMI was. CONCLUSION: The scaling exponent for standardizing waist circumference for BMI is age-dependent. Indices based on waist circumference adjusted for BMI are more associated with glycated haemoglobin than BMI in adolescents.