ABSTRACT: Examine body composition changes across the lifespan of HIV-infected compared to uninfected adults. Longitudinal study of antiretroviral therapy (ART)-treated HIV-infected and uninfected participants from the Multicenter AIDS Cohort Study and Women's Interagency HIV Study. Body mass index (BMI), waist (WC), hip circumference (HC), and waist-to-height ratio (WHtR) measured at semiannual visits from 1999 to 2014. The age effect on outcomes over time was investigated using multivariate, piecewise, linear mixed-effect regression models adjusted for demographics, substance use, and comorbidities. Person-visits from 2363 men (1059 HIV-infected/1304 HIV-uninfected) and 2200 women (1455 HIV-infected/745 HIV-uninfected), median ages 45 [IQR 39,51] and 40 [32,46], respectively, were included. BMI gains were slower among HIV-infected participants of 40 years or less (P < 0.001), similar between HIV-infected and uninfected persons 40 to 60 years of age, and plateaued after age 60 in both groups. WC and WHtR increased across the age spectrum (P < 0.001) regardless of HIV serostatus, with significantly greater gains in HIV-infected men more than 60. Black race and Hispanic ethnicity were associated with greater BMI and WC. Lower BMI, WC, hip circumference, and WHtR were associated with hepatitis C infection among women only, and with substance use among all participants, and with lower CD4 cell count and shorter ART duration among HIV-infected participants. Slower BMI gain among younger HIV-infected adults may be partly explained by substance use and hepatitis C infection, and suggests that lower BMI does not represent improved health. Further analysis of muscle and fat abundance and quality will advance understanding of metabolic risk over the lifespan, a key to reducing morbidity in an aging population.
