[Waist circumference reference values for screening cardiovascular risk factors in Chinese children and adolescents...

To explore the optimal threshold values of waist circumference (WC) in detecting the risk on cardiovascular (CV) among the Chinese children and adolescents.

Association of WC and CV risk factors were studied among 65 898 children and adolescents aged 7 - 18 years whose data were pooled from nine studies carried out in China. Receive-operating characteristic analysis (ROC) and logistic regression were employed to derive optimal age- and sex-specific waist circumference references for predicting the CV risk factors.

A slight increasing trend of CV risk factors was observed starting from the 75th percentile of waist circumference in the study population, while a remarkable increasing trend occurred from the 90th percentile. The optimal waist circumference thresholds for predicting high blood pressures were at the 75th percentile for both boys and girls, and at the 90th percentiles it could detect at least two of the above three CV risk factors. In comparison with children whose waist circumference was below the 75th percentile, the odds ratio of two CV risk factors doubled among children with waist circumference between 75th and 90th percentile, and increased by 6 times among children with waist circumference above the 90th percentile. The trend of high blood pressure increasing remained significant with waist circumference after having been stratified by BMI category.

The 75th and the 90th percentile of WC appeared to be the optimal cut-off points for predicting an increased and a substantially increased risk of CV factors in Chinese children and adolescents.