BODY-MASS INDEX, WAIST GIRTH, AND WAIST-TO-HIP RATIO AS INDEXES OF TOTAL AND REGIONAL ADIPOSITY IN WOMEN - EVALUATION USING RECEIVER OPERATING CHARACTERISTIC CURVES

Receiver operating characteristic (ROC) curves were constructed to ass ess the value of body mass index (BMI) as a screening measure for tota l adiposity and to examine waist-to-hip ratio (WHR) and waist circumfe rence as measures of central fat distribution. Body fat reference meas urements were determined by dual-energy X-ray absorptiometry (DXA). Th e study population comprised 96 healthy white women aged 16-80 y. A po sitive reference test was defined as a result at or above the 75th per centile for our study population for all DXA measurements. Sensitivity and specificity were calculated at several percentile cutoffs for BMI , WHR, and waist girth. The areas under the ROC curves were calculated to compare the relative ability of each anthropometric technique to c orrectly classify subjects according to the reference measurement for that technique. BMI (our 75th percentile = 27.3) performed well as a s creening measure of total adiposity, correctly identifying 83% of subj ects with a high body fat mass while misclassifying only eight subject s [four false-negatives (subjects with high fat mass who were in the l ow BMI category) and four false-positives (subjects with a low fat mas s who were in the high BMI category)]. The screening performance of WH R (our 75th percentile = 0.81) was lower, accurately categorizing 58% of subjects while misclassifying 28 subjects. By contrast, waist circu mference (our 75th percentile = 86.9 cm) was significantly better than WHR at screening for regional fat distribution, accurately classifyin g 83% of subjects and misclassifying eight subjects (P < 0.05). We con clude that BMI and waist circumference provide simple yet sensitive me thods for the estimation of total and central adiposity in groups of a dult women.