Fat distribution and longitudinal anthropometric changes in HIV-infected men with and without clinical evidence of lipodystrophy and HIV-uninfected controls: a substudy of the Multicenter AIDS Cohort Study.

BACKGROUND

Fat abnormalities are common among HIV-infected persons, but few studies have compared regional body fat distribution, including visceral fat, in HIV-infected and HIV-uninfected persons and their subsequent trajectories in body composition over time.

METHODS

Between 1999 and 2002, 33 men with clinical evidence of lipodystrophy (LIPO+), 23 HIV-infected men without clinical evidence of lipodytrophy (LIPO-), and 33 HIV-uninfected men were recruited from the four sites of the Multicenter AIDS Cohort Study (MACS). Participants underwent dual-energy x-ray absorptiometry, quantitative computerized tomography of the abdomen and thigh, and circumference measurements of the waist, hip and thigh. Circumference measurements at each semi-annual MACS visit between recruitment and 2008 were used to compare average annual anthropometric changes in the 3 groups.

RESULTS

Body mass index (BMI) was lower in LIPO+ men than in the LIPO- men and the HIV- uninfected controls (BMI: 23.6 +/- 0.4 vs 26.8 +/- 1.5 vs 28.7 +/- 0.9 kg/m(2), respectively, p < 0.001). The average amount of visceral adipose tissue (VAT) was similar in all three groups (p = 0.26), but after adjustment for BMI, VAT was higher in the LIPO+ group (169 +/- 10 cm(2)) compared to the LIPO- men (129 +/- 12 cm(2), p = 0.03) and the HIV-uninfected group (133 +/- 11 cm(2), p = 0.07). Subcutaneous adipose tissue (thigh, abdomen) and total extremity fat were less in the HIV-infected men (LIPO+ and LIPO-) than in the HIV-uninfected men. Over an average of 6 years of follow-up, waist circumference increased at a faster rate in LIPO+ group, compared to the LIPO- men (0.51 cm/year vs 0.08 cm/year, p = 0.02) and HIV-uninfected control men (0.21 cm/year, p = 0.06). The annual changes in hip and thigh circumferences were similar in all three groups

CONCLUSION

Subcutaneous lipoatrophy was observed in HIV-infected patients, even those without clinical evidence of lipodystrophy, compared to age-matched HIV-uninfected men. Despite markedly lower BMI, HIV-infected men with lipodystrophy had a similar amount of VAT as HIV-uninfected men and tended to have more rapid increases in waist circumference over 6 years of follow-up. These longitudinal increases in waist circumference may contribute to the development of cardiovascular risk in HIV-infected patients with lipodystrophy.