Abstract
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.
Acknowledgements
We thank Roberta Anding, RD, LD, CDE for guidance in the conceptualization of the project, Robert Addy, University of Texas School of Public Health, for assisting with statistical design by reviewing the analysis plan and guiding the author through statistical package set-up for complex surveys, and Tuan T. Nguyen, MD, PHD, Baylor College of Medicine, for assisting with ROC analysis. Drs Taylor and Hergenroeder were supported in part by HRSA, Maternal Child Health Bureau Leadership Education in Adolescent Health, training grant no. T71MC00011. Dr Taylor was supported in part by the Society for Adolescent Medicine Career Development Award and NIH Loan Repayment Program for Clinical Researchers from Disadvantaged Backgrounds.
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.