Bone Mineral Density in HIV+ Patients

Utilizing an extremely well-characterized HIV cohort under observation as ART-naïve or since their first exposure to HIV treatment, the investigators will conduct a cross-sectional study with prospectively collected data to determine BMD in 200 subjects. Subjects identified were initially treatment naïve when entering the University of Alabama at Birmingham (UAB) 1917 HIV Clinic between 1999 and 2010; some have been under observation without being treated with ART therapy and others were newly started on ART therapy while under observation. For each subject, the investigators will determine associations between BMD and 1) cumulative viremia, 2) ART duration, and 3) ART type. Hypothesis 1a: BMD will be lowest in HIV+ subjects with the highest levels of cumulative viremia. Hypothesis 1b: BMD will be greatest in HIV+ persons with longest duration of ART therapy, after excluding those subjects treated with tenofovir. Hypotheses 1c: BMD will be lower in subjects treated with tenofovir vs. other ART agents, after controlling for duration of therapy. Additionally, the investigators will conduct a retrospective study in 100 patients HIV+ and were ART-naïve at the time of entry into the 1917 Clinic in whom the investigators will longitudinally evaluate the relationship between HIV viral load, inflammation, and bone turnover (through the measurement of HIV copy-years viremia, interleukin-6 {IL-6}, tumor necrosis factor alpha {TNF-a}, high-sensitivity c-reactive protein {hsCRP}, osteocalcin, and urine C-telopeptide {CTX}). The investigators will compare HIV patients at a similar stage of their disease who remain treatment naïve (either due to concerns for compliance or sufficient CD4 counts without treatment) (ART-) vs. those newly started on ART (ART+). Hypothesis 2: Viral load, markers of inflammation, and markers of bone resorption will all decrease in ART+ vs. ART- persons.