Prevalence and risk factors for bone mineral density changes in antiretroviral therapy-naive human immunodeficiency virus-infected adults: a Chinese cohort study

The anti-HIV drug abacavir stimulates β-catenin activity in osteoblast lineage cells

Bone mineral density (BMD) loss in people living with HIV occurs with the initiation of combined antiretroviral therapy (cART), particularly with tenofovir disoproxil fumarate (TDF) containing cART. Switching from TDF to abacavir (ABC) or dolutegravir (DTG) leads to increased BMD. Whether BMD gains are due to cessation of TDF or anabolic effects of ABC or DTG is unclear. We investigated the effects of ABC and DTG on osteoblast lineage cells in vitro and in vivo. Primary human osteoblasts and male C57BL/6 mice were treated with individual antiretrovirals (ARVs) or a combination of ABC/DTG/lamivudine (3TC). Nearly all ARVs and cART inhibited osteogenic activity in vitro. Due to the importance of Wnt/β-catenin in bone formation, we further investigated ARV effects on the Wnt/β-catenin pathway. ABC, alone and as part of ABC/DTG/3TC, increased osteoblastic β-catenin activity as indicated by increased TOPFlash activity, hypo-phosphorylated (active) β-catenin staining, and β-catenin targeted gene expression. Mice treated with TDF had decreased lumbar spine BMD and trabecular connectivity density in the vertebrae, while those treated with ABC/DTG/3TC reduced cortical area and thickness in the femur. Mice treated with ABC alone had no bone structural changes, increased circulating levels of the bone formation marker, P1NP, and elevated expression of the Wnt/β-catenin target gene, Lef1, in osteocyte enriched samples. Further, bones from ARV-treated mice were isolated to evaluate ARV distribution. All ARVs were detected in the bone tissue, which was inclusive of bone marrow, but when bone marrow was removed, only TDF, ABC, and DTG were detected at ~0.1% of the circulating levels. Overall, our findings demonstrate that ABC activates Wnt/β-catenin signaling, but whether this leads to increased bone formation requires further study. Assessing the impact of ARVs on bone is critical to informing ARV selection and/or discovery of regimens that do not negatively impact the skeleton.

Reasons, safety and efficacy analysis for conversion of HAART to TAF/FTC/BIC among HIV-infected patients

BACKGROUND

This study aimed to determine the reasons for conversion and elucidate the safety and efficacy of transition to tenofovir alafenamide/emtricitabine/bictegravir sodium (TAF/FTC/BIC) in highly active antiretroviral therapy (HAART)-experienced HIV-infected patients in real-world settings.

METHODS

We conducted a retrospective cohort study. The treatment conversion rationales, safety, and effectiveness in 1684 HIV-infected patients with previous HAART experience who switched to TAF/FTC/BIC were evaluated at Beijing Ditan Hospital from September 2021 to Auguest 2022.

RESULTS

Regimen simplification (990/1684, 58.79%) was the most common reason for switching, followed by osteoporosis or osteopenia (375/1684, 22.27%), liver dysfunction (231/1684, 13.72%), decline in tenofovir alafenamide/emtricitabine/elvitegravir/cobicistat (TAF/FTC/EVG/c) with food restriction (215/1684, 12.77%), virological failure (116/1684, 6.89%), and renal dysfunction (90/1684, 5.34%). In patients receiving non-nucleotide reverse transcriptase inhibitors (NNRTI)-containing regimens, lipid panel changes 1 year after switching indicated a difference of 3.27 ± 1.10 mmol/L vs . 3.40 ± 1.59 mmol/L in triglyceride ( P  = 0.014), 4.82 ± 0.74 mmol/L vs . 4.88 ± 0.72 mmol/L in total cholesterol ( P  = 0.038), 3.09 ± 0.70 mmol/L vs . 3.18 ± 0.66 mmol/L in low-density lipoprotein ( P  <0.001), and 0.99 ± 0.11 mmol/L vs . 0.95 ± 0.10 mmol/L in high-density lipoprotein ( P  <0.001). Conversely, among patients receiving booster-containing regimens, including TAF/FTC/EVG/c and lopinavir/ritonavir (LPV/r), lipid panel changes presented decreased trends. We also observed an improved trend in viral load suppression, and alanine transaminase (ALT), aspartate transaminase (AST), estimated glomerular filtration rate (eGFR), and serum creatinine levels after the transition ( P  <0.001).

CONCLUSION

The transition to TAF/FTC/BIC demonstrated good treatment potency. Furthermore, this study elucidates the motivations behind the adoption of TAF/FTC/BIC in real-world scenarios, providing clinical evidence supporting the stable conversion to TAF/FTC/BIC for HAART-experienced patients.

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.

Vitamin D and Calcium Supplementation Reverses Tenofovir-Caused Bone Mineral Density Loss in People Taking ART or PrEP: A Systematic Review and Meta-Analysis

Background

The decrease of bone mineral density (BMD) after the intake of Tenofovir disoproxil fumarate (TDF)-based drugs in people living with HIV/AIDS (PLWHA) and HIV-negative key populations under pre-exposure prophylaxis (PrEP) regimen raised concerns. Previous findings on the effects of vitamin D (VD) and calcium supplements and the recovery of BMD loss were inconclusive. The optimal doses of VD and calcium and its supplementary duration remained unknown. Therefore, we conducted a systematic review and meta-analysis to synthesize current evidence on VD and calcium supplements to inform clinical practice.

Methods

We searched PubMed, Web of Science, Cochrane library, and EMBASE databases for all placebo-controlled trials and prospective cohort studies published before March 5, 2021 that investigated VD and calcium supplements in participants taking TDF-based drugs. The keywords calcium, vitamin D, Tenofovir, and BMD were used for the searches. The primary outcome was changes of spine and hip BMD. A subgroup analysis was performed to determine the factors that were related to the effects of VD supplements on BMD. Locally weighted regression (loess) was used to determine the relationships of VD supplements, supplementary duration, and changes of BMD. This study was registered at PROSPERO (No. 42021231000).

Findings

Seven eligible studies including 703 participants were included in the analyses. The meta-analysis found that VD and calcium supplementation was related to a significant increase of BMD in the spine and hip [standardized mean difference (SMD) 0.43; 95% CI, 0.25 to 0.61, p = 0.009]. Moreover, positive dose-response relationships were demonstrated between doses of VD and calcium supplements, supplementary duration, and BMD recovery. Patients who took VD with the dose level of 4,000 IU/D obtained the highest BMD improvement (SMD 0.59, 95% CI, 0.43 to 0.74). No side effects were reported on VD and calcium supplementation.

Interpretation

We found the VD and calcium supplementation was associated with increases of BMD in participants taking TDF-based drugs. An optimal supplementary dose of 4,000 IU/D for VD was suggested for clinicians. The findings could be used in clinical practice to improve the BMD outcomes in people who were taking TDF-based drugs.Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/.