Comparison of visceral fat measurement by dual-energy X-ray absorptiometry to computed tomography in HIV and non-HIV

Abstract

Background/Objectives Individuals with HIV are susceptible to visceral fat accumulation, which confers an increased risk of cardiometabolic disease. Advanced software to ascertain visceral fat content from dual-energy X-ray absorptiometry (DXA) has not been validated among this population. We sought to compare DXA with computed tomography (CT) in the measurement of visceral fat cross-sectional area (VAT) in HIV and non-HIV using Bland–Altman analyses. Subjects/Methods Data were combined from five previously conducted studies of individuals with HIV ( n = 313) and controls without HIV ( n = 144) in which paired DXA and CT scans were available. In cross-sectional analyses, DXA-VAT was compared with CT-VAT among participants with and without HIV. In longitudinal analyses, changes in VAT over time were compared between DXA and CT among participants with and without HIV receiving no intervention over 12 months and among individuals with HIV receiving tesamorelin—a medication known to reduce VAT—over 6 months. Results In HIV, DXA underestimated VAT compared with CT among individuals with increased visceral adiposity. The measurement bias was −9 ± 47 cm 2 overall, but became progressively larger with greater VAT ( P < 0.0001), e.g., −61 ± 58 cm 2 among those with VAT ≥ 200 cm 2 . Sex-stratified analyses revealed that the relationship between VAT and measurement bias was especially pronounced in men ( P < 0.0001). Longitudinally, DXA underestimated changes in VAT, particularly among those at the extremes of VAT gain or loss ( P < 0.0001). In contrast to the cross-sectional findings, the tendency for DXA to underestimate longitudinal changes in VAT was evident in both men and women. Analogous findings were seen among controls in cross-sectional and longitudinal analyses. Conclusions DXA underestimated VAT relative to CT in men with and without HIV, who had increased visceral adiposity. DXA also underestimated changes in VAT over time in men and women, irrespective of HIV status. DXA-VAT should be used with caution among both HIV and non-HIV-infected populations.

Subcutaneous and visceral fat assessment by DXA and MRI in older adults and children

“…However, the agreement between methods varied considerably, with DXA estimating lower or higher VAT values than MRI or CT without a clear pattern, possibly because GE systems estimate total VAT, whereas Hologic assesses the area in the L4/L5 intervertebral space. Although four reports showed overestimation by DXA (8,(33)(34)(35), in four studies, DXA underestimated CT/MRI values (6,9,24,36), as in the current investigation. A report in which DXA underestimated MRI by 30% (6) agrees with lower DXA VAT than MRI VAT values in APS (141 vs. 167 cm 2 ).…”

“…Among nine previous reports in adults, five studies compared VAT by DXA with CT measures (24,(33)(34)(35)(36) and four with MRI measures (6)(7)(8)(9). Of these, four used Hologic (7,24,34,36) and five GE (6,8,9,33,35) systems for DXA assessment. All correlations were strong and highly significant (r > 0.90).…”

Phenotyping of the Visceral Adipose Tissue Using Dual Energy X-ray Absorptiometry (DXA) and Magnetic Resonance Imaging (MRI) in Pigs

“…Further studies of quantifying the SAT in the android region may help to confirm or exclude this source of error. Fourman et al found an overestimation of SAT combined with an underestimation of VAT compared to a single image CT in humans by using a Hologic Horizon A DXA scanner [29].…”

Validity of dual‐energy x‐ray absorptiometry for estimation of visceral adipose tissue and visceral adipose tissue change after surgery‐induced weight loss in women with severe obesity

“…InnerCore also has overestimated VAT cross sectionally in children (13). In longitudinal studies, InnerCore has underestimated changes in VAT compared with CT (11) and lacked validity for estimating changes in VAT in children (13).…”