Direct measurement of abdominal fat by dual photon absorptiometry

We have assessed photon absorptiometry as a new technique for direct measurement of the abdominal fat percentage (AF%). The accuracy of the method was assessed in vitro with phantoms consisting of ox muscle, lard, and a mixture of both. The results showed good linearity (r = 0.999). The in vitro reproducibility and the in vivo reproducibility were s.d. = 2.0 and s.d. = 2.8 (AF%), respectively. The AF% was measured in 148 healthy post-menopausal women and found to correlate with other measurements of fatness, such as total body fat per cent (r = 0.82, P less than 0.001), body mass index (r = 0.79, P less than 0.001) and the ratio of waist-to-hip circumference (r = 0.59, P less than 0.001). The waist-to-hip ratio, an important predictor of cardiovascular disease, was more tightly correlated with AF% than with body mass index. We conclude that this method may be a useful new research tool for direct measurements of abdominal fat, a possible cardiovascular risk factor.