Bone Health in Aging HIV Infected Women

A Randomized controlled clinical trial (RCT) of immediate vs delayed switch from TDF/FTC to TAF/FTC to define the impact of switching ARV on BMD in different stages of the aging trajectory in HIV infected women. Included is a geriatric assessment based on the conceptualization of health transition across menopause. Study Hypothesis: The primary hypothesis is that switching from TDF/FTC will improve BMD to a degree that correlates with a lower fracture risk in aging HIV+ women. We will further explore our theory that the impact is greater in those in the early stages of menopause and in those who also receive a protease inhibitor (PI) as the third antiretroviral agent (ARV). Primary objectives: To determine if: 1. Switching HIV+ women on TDF/FTC to TAF/FTC increases BMD at the spine at 48 weeks relative to those who continue TDF/FTC 2. To determine if any observed improvements continue or stabilize in the year after switch. Hypothesis generating objectives: To determine if the effect of switching from TDF/FTC to TAF/FTC on BMD varies by stage of menopause and by third ARV. Study design: This study is double blind placebo controlled randomised, 1:1, multicentre strategic trial. Patients will be randomised to immediate vs delayed switch, with randomization allocation arranged to minimize differences between treatment group with respect to stage of menopause (peri- menopause vs early post menopause) and site. Study population: HIV positive women who are in the peri-menopausal period or those within 10 years post menopause to capture those with greatest risk of BMD loss. As menopause typically occurs earlier in HIV + women we include those aged 45-55 years. They must be on a cART regimen containing TDF/FTC with HIV RNA \<50 c/ml for at least 6 months. Intervention: 1. Immediate switch of TDF/FTC to TAF/FTC while maintaining the third ARV agent. 2. Delayed switch of TDF/FTC to TAF/FTC at 48 weeks while maintaining the third ARV agent. Randomization: A computer-generated randomization list will be prepared prior to study onset by a statistician unassociated with the study. Randomization will be stratified by study centre. Primary endpoint: Comparison of the immediate vs delayed group in the % change from baseline in BMD at the lumbar spine at week 48 and 96. Secondary endpoints: Will compare changes between the immediate and delayed group from data collected at screening or baseline and weeks 48 and 96. * change from baseline in BMD at hip Changes in Bone architecture as determined by Trabecular bone scan (TBS) and HRpQCT (high resolution peripheral quantitative computerized tomography) (Toronto site) Changes in 10 year fracture risk determined by country specific FRAX® (fracture risk assessment) calculator * with HIV-1 RNA \<50 c/ml Change from baseline in geriatric functional measures: frailty, performance and balance Change from baseline in muscle quality: Sarcopenia - grip strength measured by a Dynamometer Change from baseline in lipid values and Framingham cardiovascular risk scores Changes in renal tubular and glomerular function: GFR (glomerular filtration rate), Creatinine, urine albumin /creatinine and protein/creatinine, glucosuria Safety (clinical and laboratory adverse events) Changes in biomarkers of inflammation, coagulation and bone metabolism Tolerability (EuroQoL questionnaire)