4th International Workshop on Adverse Drug Reactions and Lipodystrophy in HIV 22-25 September 2002, San Diego, CA, USA

QUANTIFYING LIPOATROPHY AND LIPOHYPERTROPHY USING DEXA AND MRI

Antiviral Therapy 2002; 7:L19 (abstract 29)

B Razavi, WG Powderly, P Tebas, S Claxton, M Hoffmann, D Kampwerth and KE Yarasheski
Washington University School of Medicine, St. Louis, Mo., USA

BACKGROUND: Reductions in subcutaneous adipose tissue are common in people living with HIV/AIDS, but quantitative definitions for lipoatrophy are not available.

OBJECTIVE: We utilized whole-body dual-energy x-ray absorptiometry (DXA) and axial proton-magnetic resonance imaging (MRI) of the abdomen and thigh to evaluate differences in peripheral and central adipose tissue content and to derive threshold values for fat content that reflect lipoatrophy or central adipose accumulation.

METHODS: Fifty-six people living with HIV (23-64 years; 19-37 kg/m²; 11-44% body fat; 55 men, one woman) and 18 seronegative controls (21-59 years, 21-32 kg/m²; 6-41% body fat; 16 men, two women) were studied.

RESULTS: DXA measures of right and left leg fat percentage tended to be greater in controls than HIV (26.2 ±11.0% versus 21.2 ±8.9%; P≤0.076). MRI measures of right and left thigh subcutaneous adipose area (% thigh cross-sectional area) were not different between controls and HIV (36.5 ±11.0 versus 33.1 ±11.1%; P>0.26). MRI measures of adipose fat area in the visceral (VAT) region were greater in HIV than controls (177 ±98 versus 109 ±89 cm²; P=0.011). MRI measures of subcutaneous (SAT) and total (TAT) adipose area in the abdominal region were not different between HIV and controls (211 ±128 versus 204 ±99 cm² and 388 ±164 versus 314 ±177 cm²; P≥0.11). On the basis of regression analysis between MRI and DXA adipose measures for leg and trunk regions (±1 SD), we estimate that ≤25% adipose area in the thigh (MRI) or ≤15% leg fat % (DXA) reflects peripheral lipoatrophy. Using ±1 SD criteria, we estimate that ≥198 cm² VAT, or ≥42% VAT:TAT, or ≥34% trunk fat (DXA) reflects central adiposity, while ≤105 cm² SAT or ≤57% SAT:TAT or ≤10% trunk fat (DXA) reflects abdominal lipoatrophy.

CONCLUSION: These quantitative estimates of peripheral and central lipoatrophy and visceral lipohypertrophy may be useful in clinical trials, for example to identify subjects with adipose tissue maldistribution and to evaluate the effects of different treatment regimens.

Sponsored by NIH grants DK54163, DK49393, DK59531, DK56341 and AI25903

Presenting author: WG Powderly

2002-09-22
29

Copyright © 2002 - International Medical Press Ltd.. Reproduction of this abstract (other than one copy for personal reference) must be cleared through the Medical Editor, International Medical Press, 36 St Mary-at-Hill, London EC3R 8DU, United Kingdom.