Aim: This study aimed to evaluate whether waist measures, including waist circumference (WC) and waist-to-height ratio (WHtR), can improve the ability of body mass index (BMI) to assess the hypertension risk when used as continuous variables.
Methods: In this cross-sectional study, 82 432 Chinese children aged 9-17 years were included. Elevated BP was defined using age-sex-and-height-specific references. Logistic regression model and area under the receiver operating characteristic curve (AUC) were performed after BMI and waist measures were converted into age-and-sex-based z-scores.
Results: WHtR, but not WC, was associated with elevated BP after adjusting for BMI, with the odds ratios ranging between 1.14 (95% confidence interval: 1.04, 1.25) and 1.30 (1.21, 1.39) for one unit increase in WHtR z-score. Combined use of BMI and WHtR z-scores showed a significantly larger AUC than BMI alone (p < 0.05), while joint use of BMI and WC was not better than BMI alone.
Conclusion: WHtR, rather than WC, provided further information on hypertension risk beyond that provided by BMI alone when used as a continuous variable. This study suggests WHtR, in addition to BMI, should be included for the assessment of childhood adiposity in routine paediatric practice.
Keywords: Adolescent; body mass index; child; hypertension; waist circumference; waist-height ratio.