Accuracy of estimating intra-abdominal fat in obese women

Intra-abdominal fatness (IAF) has been linked to a cluster of risk factors for cardiovascular disease. An accurate assessment of IAF is therefore critical for clinicians when assessing disease risk. The aim of this investigation was to examine the accuracy of a previously developed equation by Treuth, Hunter, and Kekes-Szabo (1) using dual-energy absorptiometry (DXA) combined with anthropometry for predicting IAF in obese women. Thirty-five peri- and postmenopausal obese women (age: 47.0 yr±7.0; BMI: 32.2±6.3 kg/m ²; and percent fat: 43.5±6.7 %) underwent a single-slice computed tomography (CT) scan at the level of L4-L5. In addition, a total body DXA scan and anthropometric measures including waist circumference and supine sagittal diameter measures at the level of the umbilicus, were also made. DXA-IAF was predicted using the equation: -208.2 + 4.62(SD) + 0.75(A) + 1.73(W) + 0.78(DXA). (SD=anthropometric sagittal diameter, cm; A=age, yrs; W=waist circ., cm; DXA=DXA trunk fat, %). DXA-IAF was significantly correlated with CT-IAF (r=0.628, P<0.001, SEE=53.0 cm ²). However, DXA-IAF values (172.2±46.9 cm ²) significantly overestimated CT-IAF (114.0±67.1 cm ²) in this population. The results from the current study indicate that the Treuth et al. equation was not able to adequately estimate IAF in obese women. Although this equation was originally generated on a wide selection of women, a limited number of the original cohort were obese. In summary, this equation may be more generalizable for normal weight women than for obese women.