<p><b>OBJECTIVES</b>To explore the optimal threshold values of
waist circumference (WC) for detecting cardiovascular (CV)
risk factors among
Chinese children and
adolescents.</p><p><b>
METHODS</b>
Association of WC with CV
risk factors was studied among 65,898
children aged 7-18 years whose data were pooled from nine previous studies in
China. CV
risk factors in this study included
hypertension (
blood pressure above 95 percentile levels),
dyslipidemia (with one or more of the following three indexes TG > or = 1.7 mmol/L, TC > or = 5.18 mmol/L, and HDL-C < or = 1.04 mmol/L) and elevated
glucose level (
fasting plasma glucose > or = 5.6 mmol/L). Receive-operating characteristic
analysis (ROC) and
logistic regression were employed to derive optimal age- and
sex-specific
waist circumference references for predicting CV
risk factors.</p><p><b>RESULTS</b>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, which was at the 90th percentiles for detecting at least two of the above three CV
risk factors. In comparison with
children with
waist circumference below the 75th percentile, the
odds ratio of two CV
risk factors doubled among
children with
waist circumference between the 75th and the 90th percentile, and increased by 6 times among
children with
waist circumference above the 90th percentile. The trend of
high blood pressure increasing with
waist circumference remained significant after having been stratified by BMI category.</p><p><b>CONCLUSION</b>The 75th and the 90th percentiles of WC are the optimal cut-off points for predicting an increased and a substantially increased
risk of CV factors in
Chinese children and
adolescents, respectively.</p>