Liu et al. BMC Public Health 2010, 10:82 http://www.biomedcentral.com/1471-2458/10/82 Page 6 of 9 Figure 2 Receiver-operating characteristic curves for waist circumference with the clustering of cardiovascular risk factors (3 or more of high triglycerides, low high-density lipoprotein cholesterol, high low-density lipoprotein cholesterol, elevated blood pressure, and hyperglycemia) in Chinese boys (n = 982) and girls (n = 863) aged 6-12 years.