Estimating intraabdominal adipose tissue in women by dual-energy X-ray absorptiometry

The purposes of this study were 1) to derive a prediction equation for estimating the intraabdominal adipose tissue (IAAT) by using dual-energy X-ray absorptiometry (DXA) with computed tomography (CT) scans as the criterion method, 2) to examine whether a smaller, more specific region was a better estimator of IAAT than the trunk alone by drawing three regions of interest (upper trunk, lower trunk, and pelvis) in the DXA scan, and 3) to cross-validate the newly developed equations and earlier equations by Svendsen. Body composition was measured in 206 pre- and postmenopausal women by anthropometry, DXA, and CT. Subjects were randomly divided into estimation (n = 151) and validation (n = 55) samples. Body-composition variables were analyzed by stepwise multiple regression to determine equations to estimate IAAT. The two equations developed to estimate IAAT both yielded an R2 of 0.81 when using the following variables: 1) sagittal diameter, age, waist circumference, and DXA trunk percent fat, and 2) sagittal diameter, age, waist circumference, and DXA pelvic percent fat. The R2 between the actual IAAT and estimates of IAAT for both equations was 0.81, whereas the R2 values were 0.63 and 0.71 for the Svendsen equations. In conclusion, we developed new equations using DXA and other simple measures that can be used to estimate IAAT in women of varying ages and body compositions.