title: Dual-energy X-ray absorptiometry and anthropometric estimates of visceral fat in Black and White South African Women.
abstract: Visceral adipose tissue (VAT) is associated with increased risk for cardiovascular disease, and therefore, accurate methods to estimate VAT have been investigated. Computerized tomography (CT) is the gold standard measure of VAT, but its use is limited. We therefore compared waist measures and two dual-energy X-ray absorptiometry (DXA) methods (Ley and Lunar) that quantify abdominal regions of interest (ROIs) to CT-derived VAT in 166 black and 143 white South African women. Anthropometry, DXA ROI, and VAT (CT at L4-L5) were measured. Black women were younger (P < 0.001), shorter (P < 0.001), and had higher body fat (P < 0.05) than white women. There were no ethnic differences in waist (89.7 +/- 18.2 cm vs. 90.1 +/- 15.6 cm), waist:height ratio (WHtR, 0.56 +/- 0.12 vs. 0.54 +/- 0.09), or DXA ROI (Ley: 2.2 +/- 1.5 vs. 2.1 +/- 1.4; Lunar: 2.3 +/- 1.4 vs. 2.3 +/- 1.5), but black women had less VAT, after adjusting for age, height, weight, and fat mass (76 +/- 34 cm(2) vs. 98 +/- 35 cm(2); P < 0.001). Ley ROI and Lunar ROI were correlated in black (r = 0.983) and white (r = 0.988) women. VAT correlated with DXA ROI (Ley: r = 0.729 and r = 0.838, P < 0.01; Lunar: r = 0.739 and r = 0.847, P < 0.01) in black and white women, but with increasing ROI android fatness, black women had less VAT. Similarly, VAT was associated with waist (r = 0.732 and r = 0.836, P < 0.01) and WHtR (r = 0.721 and r = 0.824, P < 0.01) in black and white women. In conclusion, although DXA-derived ROIs correlate well with VAT as measured by CT, they are no better than waist or WHtR. Neither DXA nor anthropometric measures are able to accurately distinguish between high and low levels of VAT between population groups.
authors.affiliation: UCT/MRC Research Unit for Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa.
authors.forename: Lisa K
authors.initials: LK
authors.lastname: Micklesfield
authors.forename: Juliet
authors.initials: J
authors.lastname: Evans
authors.forename: Shane A
authors.initials: SA
authors.lastname: Norris
authors.forename: Estelle V
authors.initials: EV
authors.lastname: Lambert
authors.forename: Courtney
authors.initials: C
authors.lastname: Jennings
authors.forename: Yael
authors.initials: Y
authors.lastname: Joffe
authors.forename: Naomi S
authors.initials: NS
authors.lastname: Levitt
authors.forename: Julia H
authors.initials: JH
authors.lastname: Goedecke
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods*; D000273:Adipose Tissue / Q000000981:diagnostic imaging; D050154:Adiposity / Q000208:ethnology; D000293:Adolescent; D000328:Adult; D000886:Anthropometry; D044383:Black People; D049628:Body Size; D005260:Female; D006801:Humans; D050152:Intra-Abdominal Fat / Q000000981:diagnostic imaging*; D008875:Middle Aged; D056128:Obesity, Abdominal / Q000000981:diagnostic imaging* / Q000208:ethnology; D013019:South Africa / Q000453:epidemiology; D055105:Waist Circumference; D044465:White People; D055815:Young Adult