Reduced intravertebral bone marrow fat in HIV-infected men.

To measure intravertebral bone marrow fat in HIV-infected men. A cross-sectional study of HIV-positive men, subcategorized by lipodystrophy and antiretroviral status, and healthy age- and body mass index (BMI)-matched HIV-negative controls. A tertiary care academic medical institution. Fifteen HIV-infected men and nine age- and BMI-matched healthy control subjects were recruited for bone density, intravertebral bone marrow fat, and body composition measurements. Magnetic resonance spectroscopy was used to measure intravertebral marrow fat. Quantitative computed tomography was used to quantify visceral and subcutaneous fat. Dual energy X-ray absorptiometry was used to determine lumbar spine bone density. Statistical comparisons were performed according to HIV, lipodystrophy, and protease inhibitor (PI) exposure status. Intravertebral marrow fat was reduced in HIV-infected men (N = 15) compared with healthy HIV-negative controls (N = 9) (28.5 +/- 8.0 versus 37.3 +/- 12.5%, P = 0.04). Intravertebral bone marrow fat was most severely reduced in HIV-infected men with lipodystrophy compared with healthy HIV-negative controls (25.6 +/- 8.8% versus 37.3 +/- 12.5%, P = 0.04). Furthermore, nelfinavir (P = 0.02) was associated with decreased intravertebral marrow fat and indinavir (P < 0.05) was associated with increased intravertebral marrow fat in HIV-infected subjects. We demonstrated reduced intravertebral marrow fat in HIV-infected men using magnetic resonance spectroscopy. Notably, reduced marrow fat occurred in the setting of reduced bone density and may be affected by specific PI and lipodystrophy status. Further studies are necessary to determine the relationship between marrow fat and osteopenia and the effect of antiretroviral therapy on marrow fat in this population.