Increase in bone turnover markers in HIV patients treated with tenofovir disoproxil fumarate combined with raltegravir or efavirenz

HIV and fracture: Risk, assessment and intervention

OBJECTIVES

With management of comorbidity in people living with HIV (PLWH) a key component of clinical care, early loss of bone integrity and clinical fracture are recognized as important issues. This review aims to describe the epidemiology of fracture in PLWH, as well as summarizing the relative balance of factors that contribute to fracture. We also aim to describe fracture risk assessment and interventional strategies to modify the risk of fracture in this population.

RESULTS

Data from recent meta-analyses show that PLWH have significantly more fractures than the general population, with men and injecting drug users at higher risk. Modifiable factors that contribute to fracture risk in this cohort include body mass index (BMI), drug use, concurrent medications, frailty, and hepatitis C virus infection. Relating to antiretroviral therapy, current or ever tenofovir exposure has been identified as predictive of fracture but not cumulative use, and a potentially modest protective effect of efavirenz has been observed. Fracture Risk Assessment Tool scores underestimate fracture risk in PLWH with improved accuracy when HIV is considered a cause of secondary osteoporosis and bone mineral density (BMD) included.

CONCLUSION

Early consideration of risk, prompting evaluation of modifiable risk factors, frailty and falls risk with bone density imaging and prompt intervention may avert fracture in PLWH. Guidance on screening and lifestyle modification is available in international guidelines. Bisphosphonates are safe and effective in PLWH, with limited data for other agents.

Bone turnover change after randomized switch from tenofovir disoproxil to tenofovir alafenamide fumarate in men with HIV

OBJECTIVE

Bone loss in people with HIV (PWH) is poorly understood. Switching tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide (TAF) has yielded bone mineral density (BMD) increases. PETRAM (NCT#:03405012) investigated whether BMD and bone turnover changes correlate.

DESIGN

Open-label, randomized controlled trial.

SETTING

Single-site, outpatient, secondary care.

PARTICIPANTS

Nonosteoporotic, virologically suppressed, cis-male PWH taking TDF/emtricitabine (FTC)/rilpivirine (RPV) for more than 24 weeks.

INTERVENTION

Continuing TDF/FTC/RPV versus switching to TAF/FTC/RPV (1 : 1 randomization).

MAIN OUTCOME MEASURES

:[ 18 F]NaF-PET/CT for bone turnover (standardized uptake values, SUV mean ) and dual-energy x-ray absorptiometry for lumbar spine and total hip BMD.

RESULTS

Thirty-two men, median age 51 years, 76% white, median duration TDF/FTC/RPV 49 months, were randomized between 31 August 2018 and 09 March 2020. Sixteen TAF:11 TDF were analyzed. Baseline-final scan range was 23-103 (median 55) weeks. LS-SUV mean decreased for both groups (TAF -7.9% [95% confidence interval -14.4, -1.5], TDF -5.3% [-12.1,1.5], P  = 0.57). TH-SUV mean showed minimal changes (TAF +0.3% [-12.2,12.8], TDF +2.9% [-11.1,16.9], P  = 0.77). LS-BMD changes were slightly more favorable with TAF but failed to reach significance (TAF +1.7% [0.3,3.1], TDF -0.3 [-1.8,1.2], P  = 0.06). Bone turnover markers decreased more with TAF ([CTX -35.3% [-45.7, -24.9], P1NP -17.6% [-26.2, -8.5]) than TDF (-11.6% [-28.8, +5.6] and -6.9% [-19.2, +5.4] respectively); statistical significance was only observed for CTX ( P  = 0.02, P1NP, P  = 0.17).

CONCLUSION

Contrary to our hypothesis, lumbar spine and total hip regional bone formation (SUV mean ) and BMD did not differ postswitch to TAF. However, improved LS-BMD and CTX echo other TAF-switch studies. The lack of difference in SUV mean may be due to inadequate power.

Bone Quality in Relation to HIV and Antiretroviral Drugs

PURPOSE OF REVIEW

People living with HIV (PLWH) are at an increased risk for osteoporosis, a disease defined by the loss of bone mineral density (BMD) and deterioration of bone quality, both of which independently contribute to an increased risk of skeletal fractures. While there is an emerging body of literature focusing on the factors that contribute to BMD loss in PLWH, the contribution of these factors to bone quality changes are less understood. The current review summarizes and critically reviews the data describing the effects of HIV, HIV disease-related factors, and antiretroviral drugs (ARVs) on bone quality.

RECENT FINDINGS

The increased availability of high-resolution peripheral quantitative computed tomography has confirmed that both HIV infection and ARVs negatively affect bone architecture. There is considerably less data on their effects on bone remodeling or the composition of bone matrix. Whether changes in bone quality independently predict fracture risk, as seen in HIV-uninfected populations, is largely unknown. The available data suggests that bone quality deterioration occurs in PLWH. Future studies are needed to define which factors, viral or ARVs, contribute to loss of bone quality and which bone quality factors are most associated with increased fracture risk.