CD4+ cell count, viral load, and highly active antiretroviral therapy use are independent predictors of body composition alterations in HIV-infected adults: a longitudinal study.

BACKGROUND: To understand the concurrent effects of human immunodeficiency virus (HIV) infection, the immune system, and antiretroviral therapy on body composition alterations, we examined annualized composition changes in HIV-infected adults who were receiving stable antiretroviral therapy.
METHODS: With use of data from the Nutrition For Healthy Living Study, we performed multivariate analyses using longitudinal models to evaluate the relationship of CD4+ cell count, viral load, and highly active antiretroviral therapy (HAART) or antiretroviral therapy (ART) with changes in trunk and extremity composition for 110 men and 42 women who provided data relating to 194 study intervals (i.e., intervals of time between 2 assessment visits). Of these intervals, 165 involved HAART use (89.7% involved protease inhibitor-based regimens), and 29 did not involve HAART use. Patients receiving HAART or ART (who had continuous use during the interval) were compared with HAART- or ART-naive subjects.
RESULTS: The median length of intervals between visits was 12.9 months (interquartile range, 12.1-17.6 months). In models adjusted for HAART or ART use, baseline CD4+ cell count was positively associated with increased trunk fat (mean increase per year, 2.3% per 100 cells/mm3; 95% confidence interval [CI], 0.7%-3.9%]) and, in men, with increased extremity fat (mean increase per year, 1.8% per 100 cells/mm3; 95% CI, 0.6%-3.0%). Increase in CD4+ cell count predicted increased extremity lean mass (mean increase per year, 0.6% per 100 cells/mm3; 95% CI, 0.05%-1.1%). Higher baseline viral load predicted fat loss (trunk fat loss per year, -5.0% per log10 copies/mL; 95% CI, -9.4% to -0.7%; extremity fat loss per year, -3.4% per log10 copies/mL; 95% CI, -6.1% to -0.6%), as did zidovudine use (trunk fat loss per year, -10.8%; 95% CI, -20.4% to -1.4%; extremity fat loss per year, -4.9%; 95% CI, -9.8% to -0.01%). HAART use independently predicted decreased bone mineral content (extremity bone mineral content loss per year, -1.6%; 95% CI, -3.1% to -0.08%) but did not predict changes in fat or lean mass. Receipt of protease inhibitor-based HAART predicted a -1.9% decrease in extremity bone mineral content per year (95% CI, -3.6% to -0.2%), and zidovudine use predicted a -2.6% decrease in trunk bone mineral content per year (95% CI, -4.4% to -0.8%).
CONCLUSIONS: Baseline viral load, CD4+ cell count, and change in CD4+ cell count predicted alterations in trunk fat, extremity fat, and lean mass. HAART use and zidovudine use were associated with bone loss, and zidovudine use was associated with fat loss, but HAART use was not associated with fat mass changes.