GS-US-104-0423

To characterize the profile of low bone mineral density (BMD) in ≥ 50 year old male subjects and post-menopausal female subjects on any tenofovir disoproxil fumarate (TDF)-based regimen relative to

those on any non-TDF-based regimen for HIV infection.

• HIV-1 infected subjects regardless of race or ethnicity
• Use of  a stable, continuous,NRTI-containing ARV regimen for ≥ 3 years are allowed change of agents other than TDF within 3 years of study entry
• Of note, subjects in the non-TDF groups must have never taken a regimen that includes TDF (including previous exposure to TDF for pre-exposure prophylaxis (PrEP))
• Subjects included in the TDF groups must have always taken a regimen that includes TDF.
  
  Non-PI/r agents include non-nucleoside reverse transcriptase inhibitors (NNRTIs), integrase inhibitors, triple nucleoside inhibitors and nonboosted
  
  protease inhibitors.
• Male subjects must be ≥ 50 years of age
• Female subjects must be postmenopausal.

• Subject has a contraindication to DEXA scans
• Subject has a history of osteoporosis before initiating Highly Active Antiretroviral Treatment (HAART)

Dexa-Scan