Abstract P180: Waist Circumference: A More Sensitive Marker than BMI for Predicting Cardiovascular Disease

Abstract

PURPOSE: To show by Pulse Wave Velocity (PWV) determination that Waist Circumference (WC) is a more sensitive marker than BMI for predicting cardiovascular disease (CVD). METHOD: PWV was determined with the BPULS apparatus using the left external carotid and left dorsalis pedis arteries as “central” and “peripheral” points respectively. Pulses were picked up by infrared sensors and recorded simultaneously with a single lead ECG. The time delay between the two pulses is measured. A shorter time delay or faster PWV indicates decreased arterial wall elasticity. MATERIALS: A total of 957 asymptomatic Filipino subjects were studied. Males - 447; Females - 510. Age Range: 17 - 84 years. Hypertensives - 327. They were classified into subgroups according to BMI and WC. The average PWV times in seconds (adjusted for height of subjects) for each group were noted. The relationship of increased BMI and WC to variations in PWV time was determined. RESULTS: Elevated BMI does not significantly influence PWV time in: 1) All subjects (p<0.1397); 2) Females - (p<0.2372); 3) Normotensives - (p<0.0866); and, 4) Hypertensives - (p<0.1548). However, for every cm. increase in WC, there is a corresponding decline of PWV time by: 1) 0.000743 sec. (p<0.0001) in All subjects; 2) 0.00063 sec. (p<0.0001) in Females; 3) 0.000759 sec. (p<0.0001) in Normotensives; and,4) 0.00035 sec. (p<0.0001) in Hypertensives. DISCUSSION: Abnormal PWV is a high risk factor for the development of CVD. In the four groups above, elevated BMI does not significantly influence PWV time. However, in the very same groups increasing WC significantly affect PWV time. This indicates that if we rely solely on BMI to predict CVD we will miss cases which are high risks as shown by abnormal WC. CONCLUSION: Waist Circumference is a more sensitive marker than BMI for predicting cardiovascular disease.