Does waist circumference add to the predictive power of the body mass index for coronary risk?

Objectives: To examine the power of the combined measurements of body mass index (BMI) and waist circumference (WC) for the prediction of abnormality in coronary heart disease risk factors and to determine whether the additio nal measurement of WC is predictive in older men and women. Research Methods and Procedures. 1190 men and 751 women of the Baltimore Lo ngitudinal Study of Aging were dichotomized into younger (< 65 years) and o lder (65+ years) age groups. Coronary risk factors in the realms of glucose /insulin metabolism, blood pressure, and plasma lipids were assessed. The r elationship of BMI and WC, singly and combined, to 10 risk factors for coro nary heart disease was examined. Results: In younger and older men and women, BMI and WC are highly correlat ed (0.84 to 0.88). BMI and WC are also significantly correlated to all 10 c oronary risk factors in younger men and women and to 8 of the 10 in the old er men and women. Both partial correlation and logistic regression analyses revealed a modest but significant improvement in the prediction of coronar y risk in younger men and women by WC after controlling for the level of BM I. There was no improvement in the older subjects. Discussion: WC adds only modestly to the prediction of coronary risk in you nger subjects once BMI is known, and adds nothing to the production of risk in older subjects.