Validity and reliability of dual-energy X-ray absorptiometry for the assessment of abdominal adiposity.
A number of methods exist for the estimation of abdominal obesity, ranging from waist-to-hip ratio to computed tomography (CT). Although dual-energy X-ray absorptiometry (DXA) was originally used to measure bone density and total body composition, recent improvements in software allow it to determine abdominal fat mass. Sixty-five men and women aged 18-72 yr participated in a series of studies to examine the validity and reliability of the DXA to accurately measure abdominal fat. Total body fat and abdominal regional fat were measured by DXA using a Lunar DPX-IQ. Multislice CT scans were performed between L1 and L4 vertebral bodies (region of interest) using a Picker PQ5000 CT scanner, and volumetric analyses were carried out on a Voxel Q workstation. Both abdominal total tissue mass (P = 0.02) and abdominal fat mass (P < 0.0001) in the L1-L4 region of interest were significantly lower as measured by DXA compared with multislice CT. However, Bland-Altman analysis demonstrated good concordance between DXA and CT for abdominal total tissue mass (i.e., limits of agreement = -1.56-2.54 kg) and fat mass (i.e., limits of agreement = -0.40-1.94 kg). DXA also showed excellent reliability among three different operators to determine total, fat, and lean body mass in the L1-L4 region of interest (intraclass correlations, R = 0.94, 0.97, and 0.89, respectively). In conclusion, the DXA L1-L4 region of interest compared with CT proved to be both reliable and accurate method to determine abdominal obesity.
Glickman
Scott G
SG
Department of Internal Medicine, Division of Geriatric Medicine, University of Michigan, USA.
Marn
Charles S
CS
Supiano
Mark A
MA
Dengel
Donald R
DR
D000005:Abdomen; D015502:Absorptiometry, Photon / Q000592:standards*; D000273:Adipose Tissue / Q000000981:diagnostic imaging* / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D001823:Body Composition; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012044:Regression Analysis; D015203:Reproducibility of Results