Background: The relative contributions of the different classes of antiretroviral therapy (ART), HIV infection per se, and aging to body shape changes in HIV-infected patients have not been clearly defined in longitudinal studies.
Methods: Since September 1999, men enrolled in the Multicenter AIDS Cohort Study have undergone measurements of body mass index (BMI) and body circumferences at each semi-annual visit. The effect of HIV-serostatus and cumulative exposure to the three major ART classes on changes in anthropomorphic measurements occurring between 1999 and 2004 among HIV-infected and HIV-uninfected men were determined using linear mixed effects regression models.
Results: At baseline, average BMI and circumference measurements were greater in HIV-uninfected men (n = 392) than HIV-infected men (n = 661) (BMI, 27.3 versus 25.3 kg/m2; waist, 96.4 versus 90.2 cm; hip 101.3 versus 95 cm, thigh 54.1 versus 50.8 cm; arm 33.3 versus 31.7 cm, P < 0.001 for each comparison). Cumulative nucleoside reverse transcriptase inhibitor (NRTI) exposure, but not protease inhibitor or non-nucleoside reverse transcriptase inhibitor exposure, was associated with statistically significant changes in BMI (-0.11 ± 0.04 kg/m2 per year) and in circumferences of waist (-0.27 ± 0.07 cm/year), hip (-0.24 ± 0.05 cm/year), and thigh (-0.16 ± 0.03 cm/year) over the 5 years of follow-up. Independent of ART exposure, HIV-infected men had a more rapid increase in waist circumference over the study interval than did the HIV-uninfected men (difference 0.33 ± 0.15 cm/year, P = 0.02).
Conclusion: Cumulative NRTI therapy was associated with longitudinal decreases in body circumference measurements, whereas HIV-serostatus was associated with increases in waist circumference independent of ART.