Low baseline CD4+ count is associated with greater bone mineral density loss after antiretroviral therapy initiation

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.

Bone Disease in HIV: Need for Early Diagnosis and Prevention

The transformation of HIV into a manageable chronic condition has unveiled new clinical challenges associated with aging-related pathologies, including bone disease. This review explores the intricate relationship between HIV, antiretroviral therapy (ART), and bone disease, highlighting the necessity of early diagnosis and preventative strategies to mitigate the increased risk of osteopenia, osteoporosis, and fractures in people living with HIV (PLWHIV). It synthesizes the current literature to elucidate the multifactorial etiology of bone pathology in this population, that includes direct viral effects, chronic immune activation, ART-associated risks, and the impact of traditional risk factors for bone loss. Through a critical examination of modern diagnostic methods, lifestyle modifications, evidence-based preventive actions, and pharmacological treatments, the necessity for comprehensive management is highlighted, along with recommendations for integrated healthcare approaches vital for achieving optimal patient outcomes. By advocating for a proactive, patient-centered, and multidisciplinary strategy, this review proposes a plan to integrate bone health into standard HIV care through active risk identification, vigilant screening, effective preventive measures, tailored treatments, and informed decision-making, in an effort to ultimately enhance the quality of life for PLWHIV.

Long-Term Change in Bone Mineral Density in Women Living With HIV: A 10-Year Prospective Controlled Cohort Study

Women living with HIV (WLWH) may be at higher risk for osteoporosis and fragility fractures. However, limited prospective data describe long-term trajectories of bone mineral density (BMD) in WLWH versus women without HIV. Thus, in this prospective study, we aimed to compare 10-year change in areal BMD (aBMD) between WLWH (n = 49; 36.8 ± 8.8 years; 96% pre/perimenopausal) and HIV-negative women (population-based controls; n = 49; 41.9 ± 9.2 years; 80% pre/perimenopausal). In an exploratory analysis, we compared fracture history between WLWH and controls. Outcomes were lumbar spine (L1 to L4), total hip, and femoral neck aBMD at baseline and follow-up, which occurred at 13 and 10 years in WLWH and controls, respectively. We fit multivariable regression models to compare baseline and 10-year change in aBMD between groups, adjusting for osteoporosis risk factors. Within WLWH, we examined associations between aBMD and HIV-related factors, including combination antiretroviral therapy (cART) duration. WLWH were diagnosed 6.5 ± 3.7 years before baseline, 80% were on cART for 241 ± 142 weeks, and 49% had HIV plasma viral load <40 copies/mL. Before and after adjusting for osteoporosis risk factors, baseline and 10-year change in aBMD did not differ between WLWH and controls at any site. At baseline, more WLWH than controls reported a history of low-trauma fracture (30% versus 10%, p < 0.05) and major osteoporotic fracture (17% versus 4%, p < 0.05). During follow-up, the number of WLWH and controls with incident fragility fracture was not significantly different. Lifetime cART duration and tenofovir use were not associated with aBMD 10-year percent change. Higher CD4 count at baseline was positively associated with femoral neck aBMD 10-year percent change. Long-term aBMD change in this small WLWH cohort paralleled normal aging, with no evidence of influence from cART use; however, these results should be interpreted with caution given the small sample size. Larger cohort studies are needed to confirm these findings. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Effect of different antiretroviral therapy on muscle mass, bone mineral density, and trabecular bone score in Chinese HIV-infected males

This is the first study to report both greater BMD loss and muscle loss in Chinese HIV-infected males with lamivudine (3TC)-tenofovir disoproxil fumarate (TDF)-efavirenz (EFV) regimen, which highlights the importance of closely monitoring muscle mass and bone mineral density in patients treated with 3TC-TDF-EFV regimen and provides a foundation for the clinical intervention of sarcopenia and osteoporosis.

PURPOSE

To compare the effect initiating different antiretroviral therapy (ART) regimens have on muscle mass, bone mineral density (BMD), and trabecular bone score (TBS).

METHODS

We designed a retrospective study of ART-naive Chinese males with HIV (MWH) undergoing two different regimens at 1-year follow-up. All subjects underwent dual-energy absorptiometry (DXA) for BMD and muscle mass prior to ART initiation, and again 1 year later. TBS iNsight software was used for TBS. We analyzed differences in muscle mass, BMD, and TBS after different treatment arms and associations between ART regimens and changes in them.

RESULTS

A total of 76 men were included (mean age 31.83 ± 8.75 years). Mean absolute muscle mass decreased significantly from baseline to follow-up after initiation of lamivudine (3TC)-tenofovir disoproxil fumarate (TDF)-efavirenz (EFV), whereas increased significantly after initiation of 3TC-zidovudine(AZT)/Stavudine(d4T)-Nevirapine(NVP). Assignment to 3TC-TDF-EFV resulted in greater percentage loss in BMD at lumbar spine (LS) and total hip (TH) compared to 3TC-AZT/d4T-NVP, but this difference was not statistically significant at the femoral neck BMD and TBS. In the multivariable logistic regression model adjusted for covariates, the 3TC-TDF-EFV regimen was associated with higher odds of decreased appendicular and total muscle mass, LS and TH BMD.

CONCLUSIONS

This is the first study to report not only greater BMD loss but also muscle loss in Chinese MWH with 3TC-TDF-EFV regimen. Our work highlights the importance of closely monitoring muscle mass and BMD in patients treated with 3TC-TDF-EFV regimen and provides a foundation for the clinical intervention of sarcopenia and osteoporosis in them.

Secondary Osteoporosis and Metabolic Bone Diseases

Fragility fracture is a worldwide problem and a main cause of disability and impaired quality of life. It is primarily caused by osteoporosis, characterized by impaired bone quantity and or quality. Proper diagnosis of osteoporosis is essential for prevention of fragility fractures. Osteoporosis can be primary in postmenopausal women because of estrogen deficiency. Secondary forms of osteoporosis are not uncommon in both men and women. Most systemic illnesses and organ dysfunction can lead to osteoporosis. The kidney plays a crucial role in maintaining physiological bone homeostasis by controlling minerals, electrolytes, acid-base, vitamin D and parathyroid function. Chronic kidney disease with its uremic milieu disturbs this balance, leading to renal osteodystrophy. Diabetes mellitus represents the most common secondary cause of osteoporosis. Thyroid and parathyroid disorders can dysregulate the osteoblast/osteoclast functions. Gastrointestinal disorders, malnutrition and malabsorption can result in mineral and vitamin D deficiencies and bone loss. Patients with chronic liver disease have a higher risk of fracture due to hepatic osteodystrophy. Proinflammatory cytokines in infectious, autoimmune, and hematological disorders can stimulate osteoclastogenesis, leading to osteoporosis. Moreover, drug-induced osteoporosis is not uncommon. In this review, we focus on causes, pathogenesis, and management of secondary osteoporosis.

Immune Reconstitution Bone Loss Exacerbates Bone Degeneration Due to Natural Aging in a Mouse Model

BACKGROUND

Immune reconstitution bone loss (IRBL) is a common side-effect of antiretroviral therapy (ART) in people living with HIV (PWH). IRBL acts through CD4 + T-cell/immune reconstitution-induced inflammation and is independent of antiviral regimen. IRBL may contribute to the high rate of bone fracture in PWH, a cause of significant morbidity and mortality. Although IRBL is transient, it remains unclear whether bone recovers, or is permanently denuded and further compounds bone loss associated with natural aging.

METHODS

We utilized a validated IRBL mouse model involving T-cell reconstitution of immunocompromised mice. Mice underwent cross-sectional bone phenotyping of femur and/or vertebrae between 6- and 20-months-of-age by micro-computed tomography (µCT) and quantitative bone histomorphometry. CD4 + T-cells were purified at 20 months to quantify osteoclastogenic/inflammatory cytokine expression.

RESULTS

While cortical IRBL in young animals recovered with time, trabecular bone loss was permanent, and exacerbated skeletal decline associated with natural aging. At 20-months-of-age, reconstituted CD4 + T-cells express enhanced osteoclastogenic cytokines including RANKL, IL-1β, IL-17A and TNFα, consistent with elevated osteoclast numbers.

CONCLUSIONS

IRBL in the trabecular compartment is permanent and further exacerbates bone loss due to natural aging. If validated in humans, interventions to limit IRBL may be important to prevent fractures in aging PWH.

Osteonecrosis of the humeral head in a human immunodeficiency virus-infected patient under tenofovir disoproxil fumarate-emtricitabine-lopinavir/ritonavir for 10 years: a case report

Background

Human immunodeficiency virus-infected patients are 100 times more likely to develop aseptic osteonecrosis compared with the general population. While 90% of cases concern the femoral head, the involvement of humeral bone remains rare.

Case presentation

We report a case of aseptic osteonecrosis of the left humeral head complicating antiretroviral therapy in a female, 46-year-old, Bissau-Guinean human immunodeficiency virus-infected patient received in a context of progressive pain in the left shoulder followed by limitation of articular movements. Standard x-ray of the shoulder allowed us to make the diagnosis by showing a typical image of osteonecrosis. The treatment was medical combined with physiotherapy.

Conclusions

Aseptic osteonecrosis should be systematically looked for in human immunodeficiency virus patients on antiretroviral treatment. In addition to femoral head aseptic necrosis, the involvement of the humeral bone should also be considered.

Multiple vertebral compression fractures in a human immunodeficiency virus-positive patient with glucocorticoid-induced Cushing syndrome treated with percutaneous vertebroplasty: a case report

The authors present a rare case of multiple vertebral compression fractures in a young female with iatrogenic glucocorticoid-induced Cushing syndrome and concomitant human immunodeficiency virus (HIV) infection. Both long-term steroid use and HIV infection may lead to osteopenia or even osteoporosis. Multiple vertebral fractures in young patients are very uncommon and should alert the examiner to investigate any underlying cause. Treatment choices include pharmacological agents such as bisphosphonates or parathyroid hormone and even surgical interventions such as percutaneous vertebroplasty.

Antiretroviral Therapy-Induced Bone Loss Is Durably Suppressed by a Single Dose of Zoledronic Acid in Treatment-Naive Persons with Human Immunodeficiency Virus Infection: A Phase IIB Trial

BACKGROUND

Human immunodeficiency virus (HIV) infection and antiretroviral therapy (ART) are associated with bone loss leading to increased fracture rate among persons with HIV (PWH). We previously showed long-acting antiresorptive zoledronic acid (ZOL) prevented ART-induced bone loss through 48 weeks of therapy and here investigate whether protection persisted.

METHODS

We randomized 63 nonosteoporotic, treatment-naive adult PWH initiating ART to ZOL (5 mg) versus placebo in a double-blinded, placebo-controlled, phase IIb trial. Here we analyzed the long-term outcome data (144 weeks). Plasma bone turnover markers and bone mineral density (BMD) were quantified at weeks 0, 12, 24, 48, 96, and 144. Primary outcome was change in bone resorption marker C-terminal telopeptide of collagen (CTx). Repeated-measures analyses using mixed linear models were used to estimate and compare study endpoints.

RESULTS

At 96 weeks, mean CTx was 62% lower with ZOL relative to placebo (n = 46; CTx = 0.123 vs 0.324 ng/mL; P < .001); at 144 weeks a 25% difference between arms was not statistically significant. At 48 weeks, lumbar spine BMD with ZOL was 11% higher than placebo (n = 60; P < .001) and remained 9-11% higher at 96 (n = 46) and 144 (n = 41; P < .001) weeks. 144 weeks after ZOL infusion, BMD did not change at the lumbar spine (P = .22) but declined at the hip (P = .04) and femoral neck (P = .02).

CONCLUSIONS

A single dose of ZOL administered at ART initiation blunts bone resorption and BMD loss at key fracture-prone anatomical sites in treatment-naive PWH for 3 years. A multicenter randomized phase III clinical trial validating these results in a larger population is needed.

CLINICAL TRIALS REGISTRATION

NCT01228318.

Long-term trabecular bone score and bone mineral density changes in Chinese antiretroviral-treated HIV-infected individuals

This is the first 5-year analysis among persons with HIV (PWH) that reports both trabecular bone score (TBS), which is a novel index that estimates bone microarchitecture, and bone mineral density (BMD) over time to evaluate the long-term impact of antiretroviral therapy (ART) on bone health.

PURPOSE

HIV infection and antiretroviral therapy (ART) have been associated with decreased bone mineral density (BMD). This study aims to evaluate long-term changes in trabecular bone score (TBS), a novel index that estimates bone microarchitecture, and BMD among Chinese persons with HIV (PWH) treated with ART.

METHODS

We conducted a retrospective chart review of adult PWH at a large tertiary care hospital in China. Patients who had a DXA scan prior to ART and at least one follow-up DXA after ART initiation were included. Subgroup analyses examined the TBS and BMD changes in patients who switch from a non-TDF-containing regimen to one containing TDF, as compared to those who did not switch.

RESULTS

Four hundred fifty-nine PWH were included. Among 68 patients ≥ 50 years, 13 patients (19.1%) had a normal BMD but partially degraded or degraded TBS. The mean percent decrease in lumbar spine (LS) BMD nadired at 48 weeks after ART initiation and then gradually improved. Percent decrease in femoral neck (FN) and total hip (TH) BMD nadired at 96 weeks and remained stably low thereafter. After switch to a TDF-containing regimen, only percent change in TH BMD was significant (-3.2%, p = 0.006). In the regression analyses, switch to a TDF-containing regimen was not associated with long-term change in TBS or BMD.

CONCLUSION

This is the first study among PWH to evaluate the long-term impact of ART on TBS and BMD. At baseline, approximately 20% of patients had a normal BMD but impaired bone microstructure based upon TBS. For patients with 5 years of exposure to ART, there is a stabilization of TBS and BMD after initial nadir in the first 144 weeks. However, FN BMD, TH BMD, and TBS remained low at 5 years relative to baseline.

Low bone mass in people living with HIV on long-term anti-retroviral therapy: A single center study in Uganda

BACKGROUND

This study set out to determine the prevalence of low bone mass following long-term exposure to antiretroviral therapy in Ugandan people living with HIV.

METHODS

A cross-sectional study was conducted among 199 people living with HIV that had been on anti-retroviral therapy for at least 10 years. All participants had dual X-ray absorptiometry to determine their bone mineral density. The data collected included antiretroviral drug history and behavioral risk data Descriptive statistics were used to summarize the data. Inferential statistics were analyzed using multilevel binomial longitudinal Markov chain Monte Carlo mixed multivariate regression modelling using the rstanarm package.

RESULTS

One hundred ninety nine adults were enrolled with equal representation of males and females. The mean age was 39.5 (SD 8.5) years. Mean durations on anti-retroviral treatment was 12.1 (SD 1.44) years, CD4 cell count was 563.9 cells/mm3. 178 (89.5%) had viral suppression with <50 viral copies/ml. There were 4 (2.0%) and 36 (18%) participants with low bone mass of the hip and lumbar spine respectively. Each unit increase in body mass index was associated with a significant reduction in the odds for low bone mineral density of the hip and lumbar spine. The duration on and exposure to the various antiretroviral medications had no significant effect on the participant's odds for developing low bone mass. All the coefficients of the variables in a multivariable model for either hip or lumbar spine bone mass were not significant.

CONCLUSION

These results provide additional evidence that patients on long term ART achieve bone mass stabilization. Maintaining adequate body weight is important in maintaining good bone health in people on antiretroviral therapy.

Longitudinal change in bone mineral density among Chinese individuals with HIV after initiation of antiretroviral therapy

This is the first study to report changes in BMD and related risk factors among Chinese patients with HIV after initiation of tenofovir disoproxil fumarate (TDF)-containing antiretroviral therapy. Greater bone mineral density (BMD) loss was observed in patients treated with TDF, compared to those on non-TDF-containing regimens. Our findings provide important knowledge regarding the risk factors in the long-term clinical management of patients with HIV in China.

INTRODUCTION

Persons living with HIV (PLWH) are at increased risk for osteoporosis and fracture. Tenofovir disoproxil fumarate (TDF) has been associated with higher rates of bone mineral density (BMD) loss, osteoporosis, and fracture. Few studies have studied the impact among PLWH in Asia.

METHODS

We analyzed retrospectively patients from the outpatient HIV clinic of a large tertiary hospital in Beijing, China, from March 2007 to May 2016. Patients who had dual-energy X-ray absorptiometry testing prior to antiretroviral initiation and at 48 and/or 96 weeks after initiation were included in this analysis.

RESULTS

A total of 136 patients were included (mean age 36.0 ± 10.6 years) and over 90% participants were male and Han Chinese ethnicity. We observed greater declines in BMD at the spine from baseline to week 48 (-2.94% vs. -0.74%) and at the hip from baseline to week 96 (-4.37% vs. -2.34%) in the TDF group compared with the non-TDF group. With regard to HIV-specific parameters, longer duration since HIV diagnosis and undetectable viral load over time were associated with lower BMD at the hip [relative risk (RR) 0.97, 95% confidence index (CI) (0.95, 0.99) per 1 year increase and RR 0.96, 95%CI (0.94, 0.99), respectively] and femoral neck [RR 0.97, 95%CI (0.95, 0.99) per 1 year increase and RR 0.97, 95%CI (0.95, 0.998), respectively] over 96 weeks.

CONCLUSIONS

This is the first study to report changes in BMD among PLWH after initiation of TDF-based antiretroviral therapy in China. Our findings provide important knowledge for the long-term clinical management of PLWH from this region.

Prevalence and predictors of low bone mineral density in treatment-naive HIV-infected patients and its correlation with CD4 cell counts

Objective:

HIV virtually affects every organ system of the body. The skeletal system is no exception, and antiretroviral therapy (ART) has been implicated in bone diseases. However, not many studies have been done to evaluate bone disease in treatment (ART) naive HIV-infected patients, and hence, the present study was executed.

Materials and Methods:

One hundred and twenty HIV-infected ART-naive patients and 80 age- and sex-matched healthy controls were recruited for this study. A thorough history and physical examination was done followed by laboratory investigations after an overnight fasting. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry scan at the level of lumbar spine, femur, and forearm.

Results:

Of 120 ART-naive HIV-infected cases, the prevalence of osteoporosis and osteopenia was 13% and 41%, respectively, as compared to 0% and 17.5% in controls (P < 0.001). The mean BMD in cases was 0.842 g/cm² which was approximately 25% lesser than that in controls. Hypovitaminosis-D was seen in 100% of cases as compared to 65% of controls (P < 0.01). A significant association of low BMD was seen with HIV-infection per se (P < 0.001), low CD4 cell counts (P < 0.001), low Vitamin D levels (P < 0.001), long duration of disease (P < 0.04), history of opportunistic infections (P < 0.03), and history of tuberculosis in the past (P < 0.05).

Conclusion:

Bone diseases such as osteoporosis and osteopenia characterized by low BMD are very common in HIV-infected patients. Virus per se, along with low CD4 cell counts and low Vitamin D levels are major predictors of pathological fractures in these individuals.

Immature/transitional B-cell expansion is associated with bone loss in HIV-infected individuals with severe CD4+ T-cell lymphopenia

BACKGROUND

Antiretroviral therapy (ART) has led to a significant decline in HIV-related morbidity and mortality in people living with HIV (PLWH). PLWH however experience non-AIDS ageing-associated comorbidities, including decreased bone mass and osteoporosis, earlier and more severely, than uninfected people. We previously reported that total B-cell production of the key osteoclastogenic cytokine receptor activator of NF-κB ligand (RANKL) was elevated in PLWH, concurrent with a decrease in total B-cell production of RANKL's physiological moderator Osteoprotegerin (OPG). The resulting increased total B-cell RANKL/OPG ratio was significantly associated with bone loss in the appendicular (long bones), but not axial (spine) skeletons of PLWH. A role for immature/transitional B cells (BImm) in HIV-induced bone loss has not been reported.

METHODS

BImm frequency was determined by flow cytometry; plasma IL-7 was quantified by ELISA and bone mineral density (BMD) measured by dual X-ray absorptiometry (DXA) in a cross-sectional study of 62 ART-naive HIV-infected and 58 HIV-negative individuals.

RESULTS

BImm expansion correlated with the total B-cell RANKL/OPG ratio in HIV-infected individuals and inversely with BMD at the total hip, femoral neck and the lumbar spine, and with IL-7.

CONCLUSION

These data suggest that BImm contribute to the increased B-cell RANKL/OPG ratio in PLWH, and reveal a previously unrecognized link between BImm expansion and HIV-induced bone loss in the axial and appendicular skeletons of severely immunocompromised HIV-infected individuals. BImm expansion may be a novel biomarker for screening patients at risk of osteoporosis.

Osteopenia and osteoporosis among treatment-experienced people living with HIV

Introduction

Life expectancy of people living with human immunodeficiency (PLHIV) has increased mainly due to the accessibility and effectiveness of antiretroviral therapy (ART). However, adverse effects from long-term use of antiretrovirals, and the physiological changes associated with aging, may compromise the quality of life of PLHIV, in addition to causing new demands on the healthcare system.

Objectives

Estimate the frequency of osteoporosis and osteopenia in patients on prolonged ART and to verify their associated factors.

Methods

A cross-sectional study was conducted in Belo Horizonte, Minas Gerais, Brazil, from August 2017 to June 2018, in a sample of PLHIV (age ≥ 18 years) who started ART between 2001 and 2005. Data were collected through face-to-face interviews, physical evaluation, laboratory tests, and Dual-Energy X-Ray Absorptiometry Screening (DEXA). The outcome of interest was presence of bone alteration, defined as presence of osteopenia or osteoporosis in DEXA. The association between the explanatory variables and the event was assessed through odds ratio (OR) estimate, with 95% confidence interval (CI). Multiple logistic regression was performed to evaluate factors independently associated with bone alteration.

Results

Among 92 participants, 47.8% presented bone alteration (19.6% osteoporosis and 28.2% osteopenia). The variables that remained in the final logistic regression model were age ≥ 50 years (OR: 12.53; 95% CI: 4.37–35.90) and current alcohol use (OR: 2.63; 95% CI: 0.94–7.37).

Conclusions

This study showed a high frequency of bone changes, especially in PLHIV older than 50 years. This information is useful to stimulate the screening and timely intervention of this comorbidity of PLHIV on prolonged use of ART in order to prevent or minimize complications and new demands on the healthcare system.

Bone mineral density changes among people living with HIV who have started with TDF-containing regimen: A five-year prospective study

There are limited data regarding long-term BMD changes over time among treatment-naïve people living with HIV (PLHIV) after initiating combined antiretroviral therapy (cART) in Asia. We aimed to study bone mineral density (BMD) changes among treatment-naïve PLHIV started treatment with tenofovir disoproxil fumarate (TDF)- or non-TDF-containing regimen and HIV-uninfected controls in an Asian setting. The study was a five-year prospective study. BMD at lumbar spine (LS) (L1 to L4), total hip (TH), and femoral neck (FN) were measured by dual energy X-ray absorptiometry (DEXA) scans at baseline, months 12, 24 and 60. Multivariate logistic regression models were used to explore factors associated with mean BMD ≥5% reduction after 5 years of cART. A total of 106 PLHIV (75 and 31 started TDF- and non-TDF-containing regimen, respectively) and 66 HIV-uninfected individuals were enrolled. The mean percent changes of BMD were significantly different longitudinally between TDF and non-TDF users (p<0.001 for LS, p = 0.006 for TH and p = 0.02 for FN). HIV-positive status and on TDF-containing regimen was independently associated with BMD loss ≥5% at month 60 (adjusted odds ratio [aOR] 7.0, 95% confidence interval [95%CI] 2.3–21.0, P = 0.001 for LS; aOR 4.9, 95%CI 1.7–14.3, P = 0.003 for TH and aOR 4.3, 95%CI 1.6–11.2, P = 0.003 for FN) compared to HIV-uninfected individuals. In a multivariate model for PLHIV only, TDF use (vs. non-TDF, P = 0.005) and pre-treatment CD4+ count <350 cells/mm³ (vs. ≥350 cells/mm³, P = 0.02) were independently associated with ≥5% BMD loss in TH at month 60. Treatment-naïve PLHIV initiating treatment with TDF-containing regimen have higher BMD loss in a Thai cohort. TDF use and low pre-treatment CD4 count were independently associated with BMD loss at month 60 at TH. Earlier treatment initiation and interventions to prevent bone loss could improve skeletal health among PLHIV.

Clinicaltrials.gov: NCT01634607

Efficacy and safety of the regimens containing tenofovir alafenamide versus tenofovir disoproxil fumarate in fixed-dose single-tablet regimens for initial treatment of HIV-1 infection: A meta-analysis of randomized controlled trials

BACKGROUND

Tenofovir disoproxil fumarate (TDF) can cause renal and bone toxicity, which is associated with high plasma tenofovir concentrations in antiretroviral treatment of HIV-1 infected patients. Tenofovir alafenamide (TAF) is a novel tenofovir prodrug with a 90% reduction in plasma tenofovir concentrations. We aimed to assess the non-inferiority of a TAF-containing combination regimen versus a TDF-containing fixed-dose single-tablet regimen in the antiretroviral-treatment-naive, HIV-1-infected patients.

METHODS

We searched PubMed, Embase, Web of Science, and the Cochrane Trial Registry, from January 2001 to July 2019, using relevant keywords. Available data were extracted from eligible randomized trials (RCTs) and pooled as risk ratios (RRs) or standardized mean differences (SMDs) in a meta-analysis model using Stata/SE.

RESULTS

We included seven eligible randomized controlled trials (RCTs) with a total of 6269 participants. Patients who were antiretroviral-naive adults with HIV-1 on both the TAF-containing regimens and the TDF-containing regimens had similar virologic suppression effects (RR, 1.02; 95% CI, 1.00-1.04; p > 0.05) at week 24 (93.99% vs. 94.20%), week 48 (90.71% vs. 89.54%), and week 96 (86.16% vs. 84.80%). Both groups had no significant improvements in CD4 cell count for the naive patients during 48 weeks of therapy (SMD, 0.09; 95% CI, 0.01 to 0.16; p < 0.05). Both treatments were safe and well-tolerated, and most adverse events were similar as mild to moderate in severity. Moreover, compared with the TDF-containing regimens, the TAF-containing regimens in patients had significantly smaller reductions in both hip (RR, 0.33; 95CI, 0.29-0.39; p < 0.05) and spine (RR, 0.58; 95CI, 0.51-0.65; p < 0.05). Additionally, the TAF-containing regimens in patients had significantly fewer increases for renal events than those of the TDF-containing regimens through 48 weeks (0.31; 95% CI, 0.18-0.55; p < 0.05).

CONCLUSIONS

Our meta-analysis indicated that efficacy, safety, and tolerability of TAF-containing regimens were non-inferior in fixed-dose single-tablet regimens for initial treatment of HIV-1 infection. Furthermore, compared with those receiving the TDF-containing regimens, patients on the TAF-containing regimens had significant advantages in renal function, bone parameters, and lipid profile for the naive patients.

Influence of HIV Infection and Antiretroviral Therapy on Bone Homeostasis

The human immunodeficiency virus type 1 (HIV)/AIDS pandemic represents the most significant global health challenge in modern history. This infection leads toward an inflammatory state associated with chronic immune dysregulation activation that tilts the immune-skeletal interface and its deep integration between cell types and cytokines with a strong influence on skeletal renewal and exacerbated bone loss. Hence, reduced bone mineral density is a complication among HIV-infected individuals that may progress to osteoporosis, thus increasing their prevalence of fractures. Highly active antiretroviral therapy (HAART) can effectively control HIV replication but the regimens, that include tenofovir disoproxil fumarate (TDF), may accelerate bone mass density loss. Molecular mechanisms of HIV-associated bone disease include the OPG/RANKL/RANK system dysregulation. Thereby, osteoclastogenesis and osteolytic activity are promoted after the osteoclast precursor infection, accompanied by a deleterious effect on osteoblast and its precursor cells, with exacerbated senescence of mesenchymal stem cells (MSCs). This review summarizes recent basic research data on HIV pathogenesis and its relation to bone quality. It also sheds light on HAART-related detrimental effects on bone metabolism, providing a better understanding of the molecular mechanisms involved in bone dysfunction and damage as well as how the HIV-associated imbalance on the gut microbiome may contribute to bone disease.

CD4 T cell count is inversely associated with lumbar spine bone mass in HIV-infected men under the age of 50 years

HIV-infected men under the age of 50 years had a lower bone mass compared to that of HIV-uninfected men. Lower CD4 T cell counts, independent of whether antiretroviral therapy (ART) was used, were associated with lower BMD. HIV-infected patients with low CD4 T cell counts may need follow-up and intervention regarding bone health, including younger patients.

INTRODUCTION

HIV-infected patients have a low bone mineral density (BMD) owing to multifactorial interaction between common osteoporosis risk factors and HIV-related factors, including chronic inflammation and ART. Although HIV infection and ART might affect bone metabolism, little data is available for patients aged under 50 years. We aimed to investigate the association of HIV infection-induced low CD4 T cell counts and ART with BMD in men aged under 50 years.

METHODS

We performed an age- and body mass index-matched case-control study. BMD values of HIV-infected and HIV-uninfected men (< 50 years) were compared, and HIV-infected men were stratified by CD4 T cell counts and ART use.

RESULTS

After adjusting confounders, HIV-infected men with CD4 T cell counts ≥ 500 cells/μL (n = 28) and < 500 cells/μL (n = 139) had lower BMD at the femoral neck (FN, p < 0.001) and total hip (TH, p < 0.001) than HIV-uninfected men (n = 167). HIV-infected men with CD4 T cell counts < 500/μL had lower BMD at the lumbar spine (LS, p = 0.034) than those with counts of ≥ 500 cells/μL, but not at FN and TH. The CD4 T cell count (γ = 0.169, p = 0.031) was positively correlated with BMD at LS. There was no significant difference in the BMD (p = 0.499-> 0.999) between the ART-naïve (n = 75) and ART-user group (n = 92).

CONCLUSIONS

Despite their relatively younger age, HIV-infected men had a lower BMD than HIV-uninfected men. Lower CD4 T cell counts, irrespective of ART, might result in lower bone mass.

Older HIV-infected adults: complex patients-comorbidity (I)

Life expectancy in people living with HIV has increased in the past decades, since the introduction of highly active antiretroviral treatment. Increased survival comes along with new challenges for the HIV physician, as these patients will present comorbidities inherent to ageing that can appear more frequently and at younger age than the general population. The older HIV patient poses a unique challenge, as management should take into account different factors, some related to global ageing such as geriatric syndromes, traditional risk factors, social vulnerability, and age-related diseases, and others related to HIV infection like ART toxicity, drug-drug interactions, immune dysregulation and chronic inflammation. All the above can amount to great polypharmacy and multimorbidity that physician have to be aware of. Little is known about the best screening, management and treatment strategies to improve long-term health outcomes in this ageing population. The following article briefly reviews the main comorbidities that can affect the ageing HIV patient.

Prevalence of Bone Loss and the Short-Term Effect of Anti-retroviral Therapy on Bone Mineral Density in Treatment-Naïve Male Japanese Patients with HIV

Background:

There have been few studies have shown the relationship between HIV and low Bone Mineral Density (BMD) in Asian countries. In particular, research on the early impact of anti-HIV drugs on BMD is scarce.

Objective:

We studied the prevalence of bone loss and changes of BMD after the start of Anti-Retroviral Therapy (ART) in Japanese naïve patients with HIV.

Methods:

Male patients with HIV who visited our hospital between 2010 and 2016 were enrolled. Patients underwent BMD analyses before and one year after ART. Changes in BMD after ART initiation were evaluated by paired t-tests. To identify clinical factors affecting BMD after ART initiation based on the BMD change ratio, multiple regression analysis was performed.

Results:

Thirty-one patients were followed up. By employing the T-scores in the lumbar spines and femoral necks, the prevalence of osteopenia and osteoporosis was found to be 38.7-45.2% and 6.2% respectively. There were significant BMD decreases after ART initiation. Use of Tenofovir Disoproxil Fumarate (TDF) / emtricitabine (FTC), use of Protease Inhibitors (PIs), and low CD4 cell counts were independent risk factors for lumbar spine BMD decrease. Urinary N-terminal telopeptide / creatinine was the independent risk factor for femoral neck BMD decrease.

Conclusions:

Low BMD was prevalent in our study cases. Low CD4 cell counts at the onset of ART initiation, TDF/FTC use, and PI use increased the risk of lumbar spine BMD decrease significantly more, while ART affected femoral neck BMD of patients with higher bone metabolic activity significantly more.

Effect of Testosterone Use on Bone Mineral Density in HIV-Infected Men

HIV-infected men have increased rates of osteoporosis and fracture compared to HIV-uninfected men. Testosterone use among HIV-infected men is common. In HIV-uninfected men, testosterone increases bone mineral density (BMD), but its effects have not been evaluated in HIV-infected men. In a substudy of Multicenter AIDS Cohort Study (MACS), the Bone Strength Substudy (BOSS) enrolled 202 HIV-infected and 201 HIV-uninfected men aged between 50 and 69 years. Study participants underwent dual-energy X-ray absorptiometry (DXA) at the lumbar spine (LS), total hip (TH), and femoral neck (FN) and detailed assessment of osteoporosis risk factors. We used multivariable linear regression to determine associations and 95% confidence intervals (CIs) between self-reported testosterone use and T-scores at the LS, TH, and FN after adjustment for demographics, behavioral covariates, comorbidities, and other traditional osteoporosis risk factors. HIV-infected men reported more frequent testosterone use (22% vs. 4%; p < .001) and had lower median BMD T-score at TH than HIV-uninfected men (0.0 vs. 0.3; p = .045) but similar T-scores at LS and FN. In the overall study population, testosterone use was associated with significantly greater BMD T-score at LS (0.68; 95% CI: 0.22-1.13). In HIV-infected men with virologic suppression, testosterone was significantly associated with higher BMD T-score at LS (0.95; 95% CI: 0.36-1.54) and TH (0.45; 95% CI: 0.04-0.86). Current testosterone use is common in HIV-infected men and was associated with higher BMD, compared to those not taking testosterone. Testosterone's role in reducing fracture risk in HIV-infected men should be investigated.

Occurrence & predictors of osteoporosis & impact of body composition alterations on bone mineral health in asymptomatic pre-menopausal women with HIV infection

Background & objectives:

Data on bone mineral density (BMD) and sarcopenia are scant from young females with HIV. This study was conducted to determine occurrence, predictors and impact of body composition alterations on osteoporosis in pre-menopausal women with HIV.

Methods:

A total of 214 females with serologically documented HIV infection were screened, of whom 103 pre-menopausal women, 25-45 yr age, clinically stable, having at least one year follow up data, underwent hormonal and dual-energy X-ray absorptiometry analysis for BMD and body composition. Seventy five matched controls were also evaluated.

Results:

Females with HIV had significantly lower BMD and Z-score at lumbar spine (LS), total femur, neck of femur (NOF), and radius ultra-distal (UD) compared to controls. Osteoporosis at least at one site was observed in 34.95 per cent patients, compared to eight per cent in controls (P <0.001). Most common site of osteoporosis in females with HIV was radius UD (24.27%), followed by radius 33 per cent (17.48%), radius total (15.53%) and greater trochanter, NOF and LS (6.80% each). HIV patients had significantly lower bone mineral content, lean mass (LM), fat per cent, android (A) fat, gynoid (G) fat, and A/G ratio. LM and fat mass (FM) were −15.65 and −11.54 per cent lower in HIV patients, respectively. Osteoporosis patients had significantly higher use of antiretroviral therapy and lower LM, FM and fat per cent. On logistic regression, LM followed by A/G ratio and BMI were the best predictors of osteoporosis. Sarcopenia was observed in 17.5 per cent patients.

Interpretation & conclusions:

Our results showed that osteoporosis and sarcopenia were significant problems in young women with HIV. HIV was associated with greater LM loss, which was critical for bone health. Sarcopenia may predict low BMD in HIV.

Reduced bone mineral density among HIV-infected, virologically controlled young men: prevalence and associated factors

OBJECTIVE

Reduced bone mineral density (BMD) is a frequent comorbidity observed in people living with HIV (PLHIV). We aimed to determine the prevalence of reduced BMD and its associated factors among young PLHIV men, virologically controlled by combination antiretroviral therapy (cART).

DESIGN

A bicentric cross-sectional study.

METHODS

We selected men, aged less than 50 years, treated by cART, with HIV-RNA less than 50 copies/ml. BMDs of lumbar spine and hip were measured by dual-energy X-ray absorptiometry (DXA). A Z-score at either site between -1.0 and -2.0 or -2 or less defined osteopenia or osteoporosis, respectively. Linear and polytomous logistic regression analyses were performed.

RESULTS

Among 230 men with a median age of 43 [interquartile range (IQR), 36-47] years, BMI of 23.5 (21.3-25.3) kg/m(2) and median duration of cART of 4.2 (1.7-8.5) years, reduced BMD was diagnosed in 48.3%. In multivariate analyses, BMI decrease was associated with a risk of osteopenia [odds ratio (OR) = 1.17, P < 0.01] and osteoporosis (OR = 1.24, P < 0.01). Oestradiol levels decrease were associated with osteoporosis (OR = 1.32, P < 0.05) and lower lean mass with osteopenia (OR = 2.98, P < 0.01). There was a protective effect of the duration of cART (OR = 0.87, P < 0.01), which was even greater when the duration was more than 3 years (OR = 0.44, P = 0.02).

CONCLUSION

There is a high prevalence of reduced BMD among young men, despite persistent virological control of HIV-infection. This observation raises the question of extending current recommendations for BMD assessment to PLHIV aged < 50 years for whom BMD has stabilized after cART initiation, i.e. treated for more than three years.

Women have enhanced bone loss associated with phosphaturia and CD4+ cell restoration during initial antiretroviral therapy

OBJECTIVE

We compared bone mineral density (BMD) changes and their correlates, between men and women participating in two randomized trials of initial [antiretroviral therapy (ART)] regimens, with or without tenofovir disoproxil fumarate (TDF).

METHODS

Covariates in linear regression models of 48-week hip and spine %BMD changes, by dual energy X-ray absorptiometry, included baseline and 48-week changes in plasma viral load, CD4 cells, plasma C-terminal telopeptide, procollagen 1 N-terminal propeptide and glomerular filtration rates, and the 48-week area under the curve of fractional excretion of phosphate.

RESULTS

Despite overall hip and spine BMD declines of 2.8 and 2.9%, respectively, plasma viral load suppression to less than 50 vs. at least 50 copies/ml was associated 1.0% (P = 0.02) and 0.8% (P = 0.01) less BMD decline. Women had lower baseline spine (P = 0.04; n = 59 women, 418 men) and hip BMD (P = 0.01) in adjusted models, with 1.7% more hip decline on ART than men (P = 0.001). Serum phosphate was positively associated with baseline spine BMD in women (P = 0.03) but not men, and area under the curve of fractional excretion of phosphate was negatively associated with spine BMD changes, particularly in women randomized to TDF regimens (P = 0.03 and 0.054 for interactions by sex, and randomization to TDF vs. non-TDF regimens, respectively; n = 44 women, 326 men). Women also had 0.6% (P = 0.004) more hip BMD decline than men associated with each 100 CD4 cells/μl increase on ART (P = 0.02; n = 49 women, 379 men).

CONCLUSION

Women randomized to TDF-containing ART had accentuated spine loss associated with phosphaturia, and accentuated hip loss associated with CD4 restoration, regardless of TDF exposure. Viral load suppression reduced bone loss.

Management of Reduced Bone Mineral Density in HIV: Pharmacological Challenges and the Role of Exercise

Low bone mineral density is becoming more common among people living with HIV following the use of current antiretroviral therapy drugs such as tenofovir. Although pharmacological therapies used to treat low bone mineral density are associated with adverse effects and may increase the pill burden in people living with HIV who are already burdened by antiretroviral therapy drugs, non-pharmacological strategies to prevent and treat reduced bone mineral density resulting from antiretroviral therapy drugs in people living with HIV have not been fully explored. Despite evidence that exercise is effective in increasing bone mineral density, effects of exercise on low bone mineral density resulting from antiretroviral therapy drugs in HIV infected individuals are still unknown. This review highlights gaps in the strategies used to manage reduced bone mineral density resulting from antiretroviral therapy drugs and focuses on exercise as an alternative or adjunctive strategy.

Fractures and the gut microbiome

PURPOSE OF REVIEW

The role of the gut microbiome in the pathogenesis of several inflammatory, non-AIDS comorbidities, such as cardiovascular disease, cognitive impairment and liver disease has become a focus of recent research. Low bone mineral density (BMD) and increased fracture incidence in people living with HIV (PLWH) is also widely reported, however, the relationship between alterations in the gut microbiome and bone disease in PLWH has not been previously reviewed.

RECENT FINDINGS

Murine models that manipulate the gut microbiome, either through breeding of 'germ-free' mice or antibiotic-depleted gut microbiome, show differences in bone mineral density and bone mass in those with altered gut microbiome. This effect is reported to be driven via changes in the gut-immune-skeletal axis, with changes favouring bone resorption. Several inflammatory conditions wherever bone loss is a prominent feature, such as rheumatoid arthritis and inflammatory bowel disease, have also reported alterations in the gut microbiome, which are associated with bone loss, again through changes in the gut-immune-skeletal axis.

SUMMARY

The interplay between the gut microbiome and the immune-skeletal axis in HIV represents a complex relationship. Alterations in the gut microbiome, which induce an activated immune phenotype and inflammatory milieu are associated with non-AIDS comorbidities in PLWH and bone loss in several other conditions characterized by chronic immune activation and inflammation. It is, therefore, likely that there are comparable effects between altered gut microbiome and bone loss in HIV, however, further research is required to better define this relationship in populations of PLWH.

Relationships Between Physical Activity and Bone Density in People Living with HIV: Results from the SATURN-HIV Study

We conducted a cross-sectional secondary analysis of baseline data from the SATURN-HIV study (N = 147; 78% male, 68% Black, median body mass index [BMI] 26.72 kg/m2, 13% with osteopenia, HIV-1 RNA < 1,000 copies/mL, stable antiretroviral therapy [ART]) to explore the relationship between physical activity (PA) and bone mineral density (BMD). We measured self-reported minutes of PA and BMD in the overall sample and subgroups based on national recommendations (≥150 minutes/week). Forty-one (28%) participants met recommended PA levels. Higher intensity PA was associated with higher BMD at the total hip (r = 0.27, p = .09; n = 41; 28%) and lumbar spine (r = 0.32, p < .05), and predicted higher BMD at the hip (p < .01; controlling for age, BMI, ART). Lumbar spine BMD did not retain significance in the regression model. Moderate-to-high intensity PA could prevent or mitigate excessive bone loss in people living with HIV.

T-cell receptor activator of nuclear factor-κB ligand/osteoprotegerin imbalance is associated with HIV-induced bone loss in patients with higher CD4+ T-cell counts

OBJECTIVE

Higher incidence of osteopenia and osteoporosis underlie increased rates of fragility fracture in HIV infection. B cells are a major source of osteoprotegerin (OPG), an inhibitor of the key osteoclastogenic cytokine receptor activator of nuclear factor-κB ligand (RANKL). We previously showed that higher B-cell RANKL/OPG ratio contributes to HIV-induced bone loss. T-cell OPG production in humans, however, remains undefined and the contribution of T-cell OPG and RANKL to HIV-induced bone loss has not been explored.

DESIGN

We investigated T-cell OPG and RANKL production in ART-naive HIV-infected and uninfected individuals in relation to indices of bone loss in a cross-sectional study.

METHODS

T-cell RANKL and OPG production was determined by intracellular staining and flow cytometry, and plasma levels of bone resorption markers were determined by ELISA.

RESULTS

We demonstrate for the first time in-vivo human T-cell OPG production, which was significantly lower in HIV-infected individuals and was coupled with moderately higher T-cell RANKL production, resulting in a significantly higher T-cell RANKL/OPG ratio. T-cell RANKL/OPG ratio correlated significantly with BMD-derived z-scores at the hip, lumbar spine and femur neck in HIV-infected individuals with CD4 T-cell counts at least 200 cells/μl but not in those with lower counts.

CONCLUSION

Our data suggest that T cells may be a physiologically relevant source of OPG and T-cell RANKL/OPG imbalance is associated with HIV-induced bone loss in CD4 T-cell-sufficient patients. Both B and T lymphocytes may thus contribute to HIV-induced bone loss.

Reduced bone mineral density in human immunodeficiency virus-infected individuals: a meta-analysis of its prevalence and risk factors

A meta-analysis was conducted to evaluate the prevalence of osteopenia/osteoporosis in human immunodeficiency virus (HIV)-infected individuals. The prevalence of osteopenia/osteoporosis in HIV-infected and antiretroviral therapy (ART)-treated individuals was significantly higher than respective controls. Evidence regarding bone loss within first year of HIV infection or ART initiation was preliminary.

PURPOSE

The aim of the study is to systematically review published literature on the prevalence of osteopenia/osteoporosis and its associated risk factors in HIV-infected individuals.

METHODS

A literature search was conducted from 1989 to 2015 in six databases. Full text, English articles on HIV-infected individuals ≥ 18 years, which used dual X-ray absorptiometry to measure BMD, were included. Studies were excluded if the prevalence of osteopenia/osteoporosis was without a comparison group, and the BMD/T-score were not reported.

RESULTS

Twenty-one cross sectional and eight longitudinal studies were included. The prevalence of osteopenia/osteoporosis was significantly higher in both HIV-infected [odds ratio (OR) = 2.4 (95%Cl: 2.0, 2.8) at lumbar spine, 2.6 (95%Cl: 2.2, 3.0) at hip] and ART-treated individuals [OR = 2.8 (95%Cl: 2.0, 3.8) at lumbar spine, 3.4 (95%Cl: 2.5, 4.7) at hip] when compared to controls. PI-treated individuals had an OR of 1.3 (95%Cl: 1.0, 1.7) of developing osteopenia/osteoporosis compared to controls. A higher proportion of tenofovir-treated individuals (52.6%) had lower BMD compared to controls (42.7%), but did not reach statistical significance (p = 0.248). No significant difference was found in the percent change of BMD at the lumbar spine, femoral neck, or total hip from baseline to follow-up between HIV-infected, PI-treated, tenofovir-treated, and controls. Older age, history of bone fracture, low BMI, low body weight, being Hispanic or Caucasian, low testosterone level, smoking, low CD4 cell count, lipodystrophy, low fat mass, and low lean body mass were associated with low BMD.

CONCLUSIONS

The prevalence of osteopenia/osteoporosis in HIV-infected and antiretroviral therapy (ART)-treated individuals was two times more compared to controls. However, evidence concerning bone loss within the first year of HIV infection and ART initiation was preliminary.

Changes in bone turnover markers with HIV seroconversion and ART initiation

Background

Osteoporosis is common among HIV-infected persons and contributes to risk of fragility fracture. While ART initiation is associated with decreases in bone mineral density and increases in bone turnover, the impact of HIV on bone metabolism is unclear.

Methods

We identified men at the Chicago site of the Multicenter AIDS Cohort Study who HIV seroconverted while under observation. Concentrations of 25-OH vitamin D, bone turnover markers [procollagen type 1 N terminal propeptide (P1NP), osteocalcin (OC), C-telopeptide (CTX)] and sclerostin were measured from stored serum obtained at pre-HIV infection, pre-ART and post-ART initiation timepoints. Mixed models, with each biomarker as an outcome, were fitted. Timepoint, age, CD4 count (cells/mm 3 ), HIV-viral suppression, season and an age by timepoint interaction term were considered as fixed effects.

Results

Data from 52 participants revealed that median duration between HIV seroconversion and ART initiation was 8.7 years (IQR 3.7-11.6). Median CD4 and plasma HIV-RNA concentrations were 445 (IQR 298.5-689) and 20 184 copies/mL (IQR 6237-64 340), respectively, at the pre-ART timepoint. Multivariate analyses demonstrated pre-HIV infection levels of OC that were higher than pre-ART levels (6.8 versus 5.7 ng/mL, P  =   0.04); and pre-ART levels of sclerostin that were higher than post-ART levels (0.033 versus 0.02 ng/mL, P  <0.001). No changes in P1NP, CTX and 25-OH vitamin D levels were detected.

Conclusions

HIV seroconversion was associated with decreased OC levels while ART initiation was associated with decreases in sclerostin, a negative regulator of bone formation. Our results suggest that both HIV infection and ART have an impact on bone metabolism in white men.

The HIV co-receptor CCR5 regulates osteoclast function

C–C chemokine receptor 5 (CCR5) is a co-receptor of HIV. Epidemiological findings suggest that the functional loss of CCR5 is correlated with a lower incidence of bone-destructive diseases as well as of HIV transmission. However, it is not clear whether CCR5 is involved in regulation of the function of bone cells, in addition to that of immune cells. Here we show that blockade of CCR5 using specific antibodies impairs human osteoclast function in vitro. Ccr5-deficient (Ccr5^−/−) mice presented with dysfunctional osteoclasts and were resistant to osteoporosis induced by receptor activator of nuclear factor kappa-B ligand (RANKL), which triggers osteoporosis independently of inflammatory and immunomodulatory pathways. Furthermore, Ccr5 deficiency impairs the cellular locomotion and bone-resorption activity of osteoclasts, which is associated with the disarrangement of podosomes and adhesion complex molecules including Pyk2. Overall, the data provides evidence that CCR5 has an essential role in bone-destructive conditions through the functional regulation of osteoclasts.

CCR5 is a co-receptor for HIV, and loss of function is associated with lower incidence of HIV but also with bone-destructive diseases. Here the authors show that ablation of CCR5 impairs osteoclast function and improves resistance to osteoporosis in mouse models.

Bone and the Immune System

Osteoporosis increases fracture risk, a cause of crippling morbidity and mortality. The immunoskeletal interface (ISI) is a centralization of cell and cytokine effectors shared between skeletal and immune systems. Consequently, the immune system mediates powerful effects on bone turnover. Physiologically, B cells secrete osteoprotegerin (OPG), a potent anti-osteoclastogenic factor that preserves bone mass. However, activated T cells and B cells secrete pro-osteoclastogenic factors including receptor activator of Nuclear factor-kappaB (NF-kB) ligand (RANKL), Interleukin (IL)-17A, and tumor necrosis factor (TNF)-α promoting bone loss in inflammatory states such as rheumatoid arthritis. Recently, ISI disruption has been linked to osteoporosis in human immunodeficiency virus (HIV) infection/acquired immunodeficiency syndrome (AIDS), where elevated B cell RANKL and diminished OPG drive bone resorption. HIV-antiretroviral therapy paradoxically intensifies bone loss during disease reversal, as immune reconstitution produces osteoclastogenic cytokines. Interestingly, in estrogen deficiency, activated T cells secrete RANKL, TNF, and IL-17A that amplify bone resorption and contribute to postmenopausal osteoporosis. T cell-produced TNF and IL-17A further contribute to bone loss in hyperparathyroidism, while T cell production of the anabolic Wingless integration site (Wnt) ligand, Wnt10b, promotes bone formation in response to anabolic parathyroid hormone and the immunomodulatory costimulation inhibitor cytotoxic T lymphocyte-associated protein-4-IgG (abatacept). These findings provide a window into the workings of the ISI and suggest novel targets for future therapeutic interventions to reduce fracture risk.

Immediate Initiation of Antiretroviral Therapy for HIV Infection Accelerates Bone Loss Relative to Deferring Therapy: Findings from the START Bone Mineral Density Substudy, a Randomized Trial

Both HIV infection and antiretroviral therapy (ART) are associated with lower bone mineral density (BMD) and increased fracture risk. Because the relative contributions of ART and untreated HIV to BMD loss are unclear, it is important to quantify the effect of ART on bone. We compared the effect of early ART initiation (CD4 >500 cells/μL) with deferred ART on change in BMD in the START Bone Mineral Density substudy, a randomized trial evaluating the effect of immediate ART initiation versus deferring ART (to CD4 <350 cells/μL). BMD was measured annually at the lumbar spine and hip by dual-energy X-ray absorptiometry (DXA). Percent change in BMD by treatment assignment (intent-to-treat analysis) was estimated using longitudinal mixed models and linear regression. Baseline and follow-up DXA scans were available for 399 (195 immediate, 204 deferred) participants (median age 32 years, 80% non-white, 26% women, median CD4 count 642 cells/μL). ART (most commonly including tenofovir and efavirenz) was used for 95% and 18% of follow-up in the immediate and deferred ART groups, respectively. Through 2.2 years mean follow-up, immediate ART resulted in greater BMD declines than deferred ART at the hip (-2.5% versus -1.0%; difference -1.5%, 95% confidence interval [CI] -2.2 to -0.8, p < 0.001) and spine (-1.9% versus -0.4%; difference -1.6%, 95% CI -2.2 to -1.0, p < 0.001). BMD declines were greatest in the first year of ART. In the immediate ART group, spine BMD stabilized after year 1, whereas hip BMD declined progressively over 2 years. After year 1, BMD changes were similar in the immediate and deferred groups. No clinical, HIV-related, or ART characteristic predicted greater BMD loss in either group. All HIV treatment guidelines now recommend ART initiation at HIV diagnosis because of the reduced risk of serious clinical outcomes. Better understanding of the longer-term consequences of the observed reductions in BMD is needed.

CLINICAL TRIALS REGISTRATION

NCT00867048. © 2017 American Society for Bone and Mineral Research.

Bone mineral density in people living with HIV: a narrative review of the literature

Bone health status is largely absent in South Africa, the main reasons being the absence and cost-effectiveness of specific screening equipment for assessing bone mineral density (BMD). Various risk factors seem to play a role, some of which can be modified to change bone health status. Urbanisation is also a public health concern. Changing nutritional, as well as social behaviour, play integral roles in the prevalence and incidence of decreased BMD. Furthermore, human immunodeficiency virus (HIV) specifically, has a negative impact on BMD and although highly active antiretroviral therapy increases the prognosis for HIV-infected individuals, BMD still seem to decrease further. Dual energy X-ray absorptiometry is considered the gold standard for BMD assessment; however, recent developments have provided more cost-effective screening methods, among which heel quantitative ultrasound appears to be the most widely used in resource limited countries such as South Africa.

Frailty in HIV infected people: a new risk factor for bone mineral density loss

OBJECTIVE

The study aims to assess the association between bone mineral density (BMD) and frailty in a cohort of HIV-infected patients.

DESIGN

A cross-sectional study in an HIV outpatient unit where nearly 1000 patients are monitored.

METHODS

Study participants undergoing bone densitometry were proposed an evaluation of frailty using criteria of the Cardiovascular Health Study (CHS) and the Study of Osteoporotic Fractures (SOF). Frailty markers were weight-loss, self-reported exhaustion, physical activity, grip strength, chair stands, and slow gait. Patients' characteristics were collected from an electronic medical record. Associations of frailty with BMD and osteoporosis were tested using multivariate linear and logit regression models, respectively.

RESULTS

In total, 175 HIV-infected patients, 121 (69.14%) men, were analyzed. Prevalence of frailty markers, osteopenia, and osteoporosis were comparable among sexes. Despite a younger age, spinal and femoral neck BMD were lower in women (P < 0.05). Linear regression model adjusting by age, duration of HIV follow-up, BMI, smoking status, osteoarthritis, osteoporosis treatment, and the age at menopause showed a negative association of spinal and femoral BMD with frailty according to SOF criteria in women (P < 0.05). In men, SOF-defined frailty was associated with osteoporosis (odds ratio 28.79; 95% confidence interval 2.15-386.4) in a model adjusting for age, duration of HIV follow-up, CD4 nadir, CD4 T-cell count, tobacco consumption, exposure to tenofovir (TDF) and protease inhibitors. No significant associations were found between BMD and CHS-defined frailty.

CONCLUSION

Our study shows that frailty according to SOF criteria is associated with low spinal BMD values in female and osteoporosis in male HIV-infected patients.

Geriatric syndromes: new frontiers in HIV and sarcopenia

: HIV infection, in many circumstances, can now be managed as a chronic disease due to the marked increase in life expectancy since the introduction of combination antiretroviral therapy (ART). As the patients who first had access to combination ART age into their 50s and 60s, the effects of chronic HIV infection on health have become an important research focus in HIV infection. People living with HIV appear to exhibit an earlier occurrence of some aging-related conditions compared to people without HIV, in part due to higher rates of comorbidities, high-risk behaviors (e.g. smoking, substance use), chronic immune activation, inflammation, and ART-specific factors. Some studies have even suggested an earlier-than-expected appearance of the 'geriatric syndromes,' which are complex medical syndromes of older adults that are associated with morbidity and mortality. The geriatric syndromes include a wide variety of disease processes ranging from incontinence and dementia to impairments in physical function. This review will focus on one geriatric syndrome, sarcopenia, in older HIV-infected populations, and its relation to other aging syndromes, including frailty and falls. The contribution of HIV itself, ART exposure, and specific comorbidities, and the importance of early recognition and prevention of these aging syndromes will be highlighted.

Immunologic Effects of Maraviroc in HIV-Infected Patients with Severe CD4 Lymphopenia Starting Antiretroviral Therapy: A Sub-Study of the CADIRIS Trial

Background:

We aimed to describe the mechanisms of immunological recovery and the effects of blocking CCR5 in patients starting ART with advanced HIV-infection.

Methods:

This was a sub-study of a 48 week double-blind, clinical trial where patients starting ART with CD4+ cell counts <100 cells/uL were randomized to receive maraviroc or a placebo. CD4+ and CD8+ cell maturation phenotypes, expression of PD-1 and CCR5, and activation indices were measured at weeks 0, 4, 12, 24, and 48. The reactivity of CD4+ and CD8+cells with peptides of CMV and MTb, and with Staphylococcal enterotoxin B (SEB) was assessed by intra-cellular expression of IFNγ, TNFα, and CD40 ligand at weeks 0, 4, and 12 of ART.

Results:

Forty patients were included in the study (Maraviroc = 22; placebo = 18). Sustained increases in CD8+ cells and in proportions of CCR5+ CD4+ and CD8+ cells were observed in the maraviroc arm. Early increases in the proportions of activated (CD38+, HLA-DR+), PD-1+ CD4+, and CD8+ cells and more matured CD8+ cells, were observed in the maraviroc arm. T cell responses to CMV, MTb, and SEB did not differ by treatment arms.

Conclusions:

During antiretroviral therapy in advanced HIV infection, maraviroc retains mature, activated CCR5+ cells in circulation without impact on CD4+ T cell recovery or T cell reactivity to antigen or superantigen.

Complete manuscript Title: Changes in RANKL during the first two years after cART initiation in HIV-infected cART naïve adults

Background

By assessing the changes in concentration of soluble receptor activator of nuclear factor κ B ligand (RANKL) and osteoprotegrin (OPG) after initiation of combination antiretroviral therapy (cART) in treatment-naïve HIV-infected patients we aimed to evaluate whether the initial accelerated bone loss could be mediated by increased soluble RANKL (sRANKL) levels associated with CD4+ T cell recovery.

Methods

We used multiplex immunoassays to determine sRANKL and OPG concentrations in plasma from 48 HIV patients at baseline and 12, 24, 48 and 96 weeks after cART initiation.

Results

Soluble RANKL changed significantly over time (overall p = 0.02) with 25% decrease (95% CI: -42 to −5) at week 24 compared to baseline and stabilized at a lower level thereafter. We found no correlation between CD4+ T cell count increment and changes in sRANKL or between percentage change in BMD and changes in sRANKL.

Conclusion

In this study there was no indication that the accelerated bone loss after cART initiation was mediated by early changes in sRANKL due to CD4+ T cell recovery. Future studies should focus on the initial weeks after initiation of cART.

Trial registration

Clinical-Trial.gov. id NCT00135460, August 25, 2005. The study was approved by the Danish Data Protection Agency, Danish Medicines Agency and Regional Ethics Committee.

Predictors of longitudinal change in bone mineral density in a cohort of HIV-positive and negative patients

OBJECTIVE

Although low bone mineral density (BMD) is prevalent in HIV, changes in BMD over time remain unclear. We aimed to compare rates of, and factors associated with, BMD change between HIV-positive and HIV-negative patients.

METHODS

In a prospective, 3-year cohort, HIV-positive and HIV-negative patients provided annual demographic and clinical data, fasting bloods, and dual x-ray absorptiometry. Using longitudinal mixed models we compared and determined predictors of rate of change in BMD.

RESULTS

Of 384 study participants (45.8% HIV positive), 120 contributed two and 264 contributed three BMD measurements. Those with HIV were younger [median interquartile range 39 (34-46) vs. 43 (35-50) years; P = 0.04], more often men (61 vs. 46%; P = 0.003), and less likely Caucasian (61 vs. 82%; P < 0.001). Although BMD was lower in those with HIV, BMD declined in both groups, with nonsignificant between-group difference in rate of BMD change over time. Within the HIV group, starting antiretroviral therapy (ART) within 3 months of enrolment was associated with greater BMD decline at all anatomical sites (all P < 0.001). Age more than 30 years, Caucasian ethnicity, and not being on ART during follow-up were associated with greater decline and higher parathyroid hormone associated with a smaller decline in BMD at the femoral neck. We found no association between BMD change and exposure to tenofovir disoproxil fumarate or protease inhibitors.

CONCLUSION

We observed no difference in rate of BMD decline regardless of HIV status and in HIV-positive patient, having started ART within the previous 3 months was the only factor associated with greater BMD decline at all three sites.

Bone Loss in HIV Infection

Human immunodeficiency virus (HIV) infection is an established risk factor for low bone mineral density (BMD) and subsequent fracture, and treatment with combination antiretroviral therapy (cART) leads to additional BMD loss, particularly in the first 1-2 years of therapy. The prevalence of low BMD and fragility fracture is expected to increase as the HIV-infected population ages with successful treatment with cART. Mechanisms of bone loss in the setting of HIV infection are likely multifactorial, and include viral, host, and immune effects, as well as direct and indirect effects of cART, particularly tenofovir disoproxil fumarate (TDF) and the protease inhibitors (PIs). Emerging data indicate that BMD loss following cART initiation can be mitigated by prophylaxis with either long-acting bisphosphonates or vitamin D and calcium supplementation. In addition, newer antiretrovirals, particularly the integrase strand transfer inhibitors and tenofovir alafenamide (TAF), are associated with less intense bone loss than PIs and TDF. However, further studies are needed to establish optimal bone sparing cART regimens, appropriate screening intervals, and preventive measures to address the rising prevalence of fragility bone disease in the HIV population.

Tenofovir and bone health

PURPOSE OF REVIEW

With continued improvements to the antiviral efficacy and tolerability of antiretroviral therapy, long-term safety of antiretroviral therapy has become paramount. Low bone mineral density and fragility fractures are more common in HIV-infected individuals than in the general population. The aims of this review are to describe potential mechanisms underlying the adverse effects of tenofovir on bone, clinical studies of tenofovir disoproxil fumarate (TDF) and bone, and more recent bone data on tenofovir alafenamide.

RECENT FINDING

Several studies have demonstrated an approximately 1-3% greater bone mineral density loss with TDF compared with other agents. Recent studies with tenofovir alafenamide have shown improved bone (and renal) safety with similar virologic efficacy when compared to TDF.

SUMMARY

Given these findings, TDF-containing regimens may be gradually replaced with non-TDF containing regimens for the treatment of HIV infection, especially in those at higher risk for fragility fracture.

Vitamin D and bone loss in HIV

PURPOSE OF REVIEW

Bone health has become an increasingly important aspect of the care of HIV-infected patients as bone loss with antiretroviral therapy (ART) initiation is significant and osteopenia and osteoporosis are highly prevalent. Vitamin D is tightly linked to calcium balance and bone health, and vitamin D deficiency is common in HIV. This review outlines the epidemiology of vitamin D deficiency in HIV, summarizes our current understanding of the relationship between vitamin D and bone loss in HIV and the impact of vitamin D supplementation in this patient group.

RECENT FINDINGS

Although data are conflicting as to whether vitamin D deficiency is more prevalent among HIV-infected individuals than in the general population, there are several reasons for why this patient group may be at heightened risk. Studies linking vitamin D deficiency to bone loss in HIV are limited; however, data from randomized clinical trials suggest a benefit of vitamin D supplementation for the prevention of bone loss with ART initiation and for the treatment of bone loss with bisphosphonate therapy.

SUMMARY

There are too limited data to recommend universal screening of vitamin D status or supplementation to all HIV-infected individuals. However, testing 25-hydroxyvitamin D levels in those at risk for deficiency and treating patients found to be deficient or initiating ART or bisphosphonate therapy should be considered. Further study on vitamin D supplementation is needed regarding the potential benefit on immune activation and restoration in this patient group.

Does systemic inflammation and immune activation contribute to fracture risk in HIV?

PURPOSE OF REVIEW

There is increasing evidence pointing toward an important role of heightened immune activation and inflammation in people living with HIV contributing to the development of non-AIDS comorbidities. This review aims to explore low bone mineral density (BMD) in HIV with a focus on the underlying mechanisms and relationships between the immune and skeletal systems.

RECENT FINDINGS

Baseline immune activation and inflammation negatively impact BMD at antiretroviral therapy (ART) initiation. B- and T-cell alterations in HIV lead to an imbalance in the osteoblastic osteoprotegerin (OPG) and osteoclastic receptor activator of NF-κB ligand (RANKL) cytokines which favours osteoclastogenesis and bone resorption. These findings suggest an important role for immune-mediated mechanisms in the pathogenesis of low BMD in HIV.

SUMMARY

Bone homeostasis is in part regulated by cells of the immune system through complex interactions with the RANK/RANKL/OPG axis. Disturbances in the normal functioning of T, B cells, and monocytes in HIV and the resulting proinflammatory state may contribute to dysregulation of this finely controlled balance leading to increased bone loss. Pre-ART levels of immune activation and inflammation have a consistently negative effect on BMD and further suggest the immunocentric basis of bone loss in HIV alongside supporting the benefits of earlier ART initiation. Further longitudinal studies will help determine the effect this will have on fracture risk in people living with HIV.

HIV and Bone Complications: Understudied Populations and New Management Strategies

The higher risk of osteoporosis and fracture associated with HIV infection and certain antiretrovirals has been well established and the need for risk stratification among older adults increasingly recognized. This review focuses upon emerging data on bone complications with HIV/HCV coinfection, in children and adolescents, and with pre-exposure prophylaxis (PrEP), as well as new management strategies to minimize the negative effects of ART on bone.