Objective: The aims of the study were to establish waist circumference (WC) cut-off points that identify clustering of obesity-related conditions and determine if the cut-off points identified an increased risk of disease when used within BMI categories.
Methods: This is a secondary analysis of the Centers for Disease Control NHANES III complex, multistage probability weighted data set collected between 1988 and 1994 from multiple locations in the United States. There were 2003 adolescents ages 12-19 years. Main outcome measures were low (<2 risk factors) or high (≥2 risk factors) risk for cardiometabolic disease based on the number of abnormal serum measurements for fasting glucose, high-density lipoprotein (HDL), triglycerides, and blood pressure. Receiver-operating characteristic curve analysis created the WC cut-off points and logistic regression determined if cut-off points predicted of within BMI categories.
Results: Analysis identified cut-off points of ≥80.5 cm for males and ≥81 cm for females. Cut-off points predicted abnormal values for all outcome variables except fasting serum glucose in females, p < 0.05. Males with a normal BMI and elevated waist circumference were more likely to be high risk (OR = 5.23, CI = 1.79, 15.24, p < 0.013) and have increased odds of abnormal serum triglycerides, HDL and blood pressure. Overweight females (BMI ≥ 85-94%) with elevated waist circumference were more likely to have elevated blood pressure (OR = 9.05, 95% CI: 1.44, 56.83).
Conclusion: WC within BMI categories may identify those who have cardiometabolic disease risk factors despite having normal or overweight BMI.