Bone Density, Microarchitecture, and Tissue Quality After Long-Term Treatment With Tenofovir/Emtricitabine or Abacavir/Lamivudine

Changes in bone quality after switching from a TDF to a TAF based ART: A pilot randomized study

BACKGROUND

The impact of tenofovir disoproxil fumarate (TDF) antiretroviral (ART) regimens on bone health has been characterized mostly by bone mineral density (BMD), but recently also by bone quality (BQ). The aim of this pilot study is to assess the changes in BMD and BQ after switch from TDF to tenofovir alafenamide (TAF) ART.

METHODS

HIV individuals receiving TDF-based ART were randomized to switch to Bictegravir-TAF-Emtricitabine or to remain in the same regimen. At baseline and 24-weeks after randomization, participants underwent bone mineral density (BMD) by DXA and BQ assessment using bone microindentation, a validated technique that measures bone tissue quality expressed as bone material strength index (BMSi). A panel of plasma bone turnover biomarkers were measured by ELISA at the same time-points. Values are expressed as median [interquartile range] and non-parametric tests were used where appropriate.

RESULTS

A total of 24 HIV individuals were included in the study, 19 of which were men (80%). Median age at baseline was 43 years (IQR 38-54). Half of individuals were allocated in the TDF group while the other half changed to TAF treatment. No differences at baseline between both groups were detected in any parameter. Non-significant changes nor in lumbar or femoral BMD at week 24 was found in any regimen. In contrast, there was an increase in BMSi in the TAF arm at 24 weeks, and thus an improvement in BQ[81.6 (79-83) to 86 (80-88) (+5.1%);p=0.041], whereas the TDF arm remained stable from 82 (76-85) at baseline to 82 (73-83);p=0.812. Hence, at week 24 there were significant differences in BQ between arms (p=0.049). A reduction in bone formation markers was found at week 24 in both regimens: N-terminal propeptide of type-1 collagen decreased a 20% (-35 - -0.6); p=0.031 with TAF and -16% (-25 - -5); p=0.032 with TDF. Also a decrease in bone resorption marker C-telopeptide with TAF was detected [-10% (-19 - -5);p=0.028] but not with TDF (p=0.232), suggesting a less metabolically active bone after switching to TAF.

CONCLUSION

A bone quality improvement was found after switching from a TDF to a TAF based ART independently of BMD, suggesting that the bone health benefits of TAF may extend beyond BMD. Future research should be directed to confirm these findings and to identify the underlying mechanisms of ART related bone toxicity.

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.

An Abnormal Inflammatory Pattern Associated with Long-Term Non-Progression of HIV Infection Impacts Negatively on Bone Quality

Introduction. Long-term non-progressors (LTNPs) are HIV-infected individuals (HIV+) whose viral replication is controlled. However, these individuals experience complications associated with HIV, among them, bone remodeling impairment. This study aims to perform a comprehensive bone health assessment and its association with the inflammatory status of HIV+ LTNPs. A cross-sectional study was conducted comparing bone strength components (bone mineral density and bone tissue quality) between age-, sex-, and comorbidities-matched groups of HIV+ LTNPs, HIV+ progressors, and HIV-negative individuals. A panel of bone turnover and inflammatory biomarkers was measured in fasting plasma using ELISA. Bone tissue quality was assessed by bone microindentation, a technique that directly measures the bone resistance to fracture and yields a dimensionless quantifiable parameter called bone material strength (BMSi). Thirty patients were included: ten LTNPs, ten HIV+ progressors, and ten HIV-negative individuals. LTNPs showed an abnormal pattern of immune activation that was represented by significantly lower levels of anti-inflammatory cytokine IL-10 (p = 0.03), pro-inflammatory cytokine IL-8 (p = 0.01), and TNF-α (p < 0.001) with respect to the other groups. Regarding bone health, LTNPs presented lower BMSi, and thus, worse bone tissue quality than HIV-negative individuals (83 (78−85) vs. 90 (89−93), respectively; p = 0.003), and also lower BMSi than HIV+ progressors (83 (78−85) vs. 86 (85−89), respectively; p = 0.022). A trend was found of lower BMSi in HIV+ progressors with respect to the HIV-negative individuals (86 (85−89) vs. 90 (89−93), respectively; p = 0.083). No differences were detected in bone mineral density between groups. In conclusion, LTNPs showed a different inflammatory profile, along with worse bone tissue quality, when compared to HIV+ progressors and HIV-negative individuals. This may contribute to increasing evidence that HIV infection itself has a deleterious effect on bone tissue, likely through a persistent altered inflammation status.

Dilemmas in the Management of Osteoporosis in Younger Adults

Osteoporosis in premenopausal women and men younger than 50 years is challenging to diagnose and treat. There are many barriers to optimal management of osteoporosis in younger adults, further enhanced by a limited research focus on this cohort. Herein we describe dilemmas commonly encountered in diagnosis, investigation, and management of osteoporosis in younger adults. We also provide a suggested framework, based on the limited available evidence and supported by clinical experience, for the diagnosis, assessment, and management of osteoporosis in this cohort. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Higher comorbidity burden predicts worsening neurocognitive trajectories in people with HIV

BACKGROUND

Age-related comorbidities accumulate faster in people with HIV (PWH) than in those without (PWoH). We evaluated whether a validated multimorbidity scale, the Charlson Index, predicted neurocognitive trajectories in PWH.

METHODS

Scaled scores a comprehensive neuropsychological battery were averaged across all visits. Multilevel modeling examined between- and within-person predictors of global neurocognition. At the between-person level, averaged Charlson scores were examined as a predictor of neurocognitive change rate, covarying for HIV disease characteristics. Within-persons, visit-specific Charlson Index was used to predict fluctuations in global neurocognition at the same and next visit, covarying for disease measures.

RESULTS

Participants were 1195 PWH (mean baseline age 43·0; SD 9·7 years) followed for a mean of 7·1 years (range 0·5-20·5). At the between-person level, more rapid neurocognitive worsening correlated with higher (worse) average Charlson scores (standardized β -0·062, SE 0·015; p=0·001) and lower CD4 nadir (standardized β 0·055, SE 0·021; p=0·011), but not viral suppression or average CD4+ lymphocytes (ps > 0·05). At the within-person level, poorer visit-specific neurocognition was related to worse concurrent, but not preceding, Charlson scores (standardized β-0·046, SE 0·015; p = 0·003), detectable HIV viral load (standardized β0·018, SE 0·006; p = 0·001) and higher CD4+ (standardized β0·043, SE 0·009; p < 0·001).

CONCLUSION

The impact of comorbidities on neurocognitive decline exceeded that of HIV disease factors. Although correlative, the temporal relationships suggested that treatment of comorbidities might improve neurocognitive prognosis for PWH.

The benefits of tenofovir discontinuation with or without bisphosphonate therapy in osteoporotic people living with HIV

OBJECTIVES

Treatment with bisphosphonates and discontinuation of tenofovir disoproxil fumarate (TDF) are recommended strategies for managing osteoporosis in people living with HIV (PLHIV). This study aimed to compare the effects on bone mineral density (BMD) of TDF discontinuation with and without bisphosphonate therapy in osteoporotic PLHIV.

METHODS

The present study is a retrospective cohort analysis of dual-energy X-ray absorptiometry scan results of PLHIV attending Chelsea and Westminster Hospital HIV clinic between 2009 and 2020. Osteoporotic (T-score < -2.5) patients with ≥ 6 months' TDF exposure were included. Changes in BMD and T-scores at the lumbar spine (LS) and femoral neck (FN) were assessed.

RESULTS

A total of 84 participants were included, of whom 43 discontinued TDF only (TS) and 41 switched from TDF and received bisphosphonates (TS+): 86.9% were male; 77.4% were white; median (interquartile range, IQR) age was 54.8 (51.0-58.5) years; and median (IQR) TDF exposure was 6.5 (3.5-10.4) years. At a median follow-up of 2 years after TDF-discontinuation, mean spine BMD increased significantly in both groups, but bisphosphonate recipients had greater improvements (4.83% vs. 7.79%; P < 0.019); LS T-scores improved significantly but changes were comparable between groups (TS, 0.5 vs. TS+, 0.6; P = 0.270). At the FN, no significant increases in BMD were observed (TS, 3.05% vs. TS+, 2.71%; P = 0.205); T-scores significantly improved in bisphosphonate recipients only (+0.2; P = 0.003). A greater proportion recovered from osteoporosis in the TS+ group (34.9% vs. 43.9%), although differences between groups were not significant (P = 0.503).

CONCLUSIONS

Our real-world data indicate that although TDF discontinuation significantly improved bone health in osteoporotic PLHIV, combining bisphosphonates with TDF discontinuation resulted in greater improvements in BMD.

Bone density, microarchitecture and tissue quality after 1 year of treatment with dolutegravir/abacavir/lamivudine

BACKGROUND

Bone mineral density (BMD) decreases with ART initiation with a tenofovir disoproxil fumarate-containing regimen, although bone tissue quality increases. The impact of dolutegravir (DTG)/abacavir (ABC)/lamivudine (3TC)-based ART initiation on bone health parameters is not clear.

OBJECTIVES

To study the impact of DTG/ABC/3TC-based therapy on bone health parameters in ART-naive individuals with HIV after 48 weeks of treatment.

METHODS

An observational, prospective and analytical study of treatment-naive patients with HIV undergoing a DTG/ABC/3TC-based regimen at 48 week follow-up. Changes in bone strength parameters (BMD, bone microarchitecture and bone tissue quality) were assessed with non-parametric methods.

RESULTS

Sixteen HIV-infected ART-naive patients starting DTG/ABC/3TC were included. BMD in the lumbar spine showed a significant decrease of -2.25% (P = 0.007) and -4.1% in the femoral neck (P = 0.007). Bone microarchitecture, as measured by trabecular bone score, also decreased significantly by -2.5% (P = 0.03). In contrast, bone quality [bone material strength index (BMi)], as measured by microindentation, significantly increased with respect to baseline after 48 weeks of treatment, showing better bone properties of +6.53% (P < 0.001). No significant changes were found in bone turnover markers. In addition, a positive significant correlation between the CD4/CD8 cell count ratio at baseline and changes in BMSi after 48 weeks of treatment was observed (Spearman's rho = 0.4974; P = 0.04).

CONCLUSIONS

After a 48 week treatment with DTG/ABC/3TC-based ART, BMD and trabecular bone score decreased while bone tissue quality, as measured by microindentation, improved significantly. The state of the immune system at ART initiation is related to bone quality recovery. An overarching approach to assess bone toxicity in ART-treated patients is needed.

The Prevalence and Burden of Non-AIDS Comorbidities Among Women Living With or at Risk for Human Immunodeficiency Virus Infection in the United States

BACKGROUND

The prevalence and burden of age-related non-AIDS comorbidities (NACMs) are poorly characterized among women living with HIV (WLWH).

METHODS

Virologically suppressed WLWH and HIV-seronegative participants followed in the Women's Interagency HIV Study (WIHS) through at least 2009 (when >80% of WLWH used antiretroviral therapy) were included, with outcomes measured through 31 March 2018. Covariates, NACM number, and prevalence were summarized at most recent WIHS visit. We used linear regression models to determine NACM burden by HIV serostatus and age.

RESULTS

Among 3232 women (2309 WLWH, 923 HIV-seronegative) with median observation of 15.3 years, median age and body mass index (BMI) were 50 years and 30 kg/m2, respectively; 65% were black; 70% ever used cigarettes. WLWH had a higher mean NACM number than HIV-seronegative women (3.6 vs 3.0, P < .0001) and higher prevalence of psychiatric illness, dyslipidemia, non-AIDS cancer, kidney, liver, and bone disease (all P < .01). Prevalent hypertension, diabetes, and cardiovascular and lung disease did not differ by HIV serostatus. Estimated NACM burden was higher among WLWH versus HIV-seronegative women in those aged 40-49 (P < .0001) and ≥60 years (P = .0009) (HIV × age interaction, P = .0978). In adjusted analyses, NACM burden was associated with HIV, age, race, income, BMI, alcohol abstinence, cigarette, and crack/cocaine use; in WLWH, additional HIV-specific indices were not associated, aside from recent abacavir use.

CONCLUSIONS

Overall, NACM burden was high in the cohort, but higher in WLWH and in certain age groups. Non-HIV traditional risk factors were significantly associated with NACM burden in WLWH and should be prioritized in clinical guidelines for screening and intervention to mitigate comorbidity burden in this high-risk population.

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.

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.

Treatments of osteoporosis increase bone material strength index in patients with low bone mass

Effects on bone material properties of two-year antiosteoporotic treatment were assessed using in vivo impact microindentation (IMI) in patients with low bone mineral density (BMD) values. Antiresorptive treatment, in contrast to vitamin D ± calcium treatment alone, induced BMD-independent increases in bone material strength index, measured by IMI, the magnitude of which depended on pretreatment values.

INTRODUCTION

Bone material strength index (BMSi), measured by IMI in vivo, is reduced in patients with fragility fractures, but there is no information about changes in values during long-term therapy. In the present study, we assessed changes in BMSi in patients receiving antiosteoporotic treatments for periods longer than 12 months.

METHODS

We included treatment-naive patients with low bone mass who had a BMSi measurement with OsteoProbe® at presentation and consented to a repeat measurement after treatment.

RESULTS

We studied 54 patients (34 women), median age 58 years, of whom 30 were treated with bisphosphonates or denosumab (treatment group) and 24 with vitamin D ± calcium alone (control group). There were no differences in clinical characteristics between the two groups with the exception of a higher number of previous fragility fractures in the treatment group. Baseline hip BMD and BMSi values were lower in the treatment group. After 23.1 ± 6.6 months, BMSi increased significantly in the treatment group (82.4 ± 4.3 vs 79.3 ± 4.1; p < 0.001), but did not change in the control group (81.5 ± 5.2 vs 82.2 ± 4.1; p = 0.35). Changes in BMSi with antiresorptives were inversely related with baseline values (r = - 0.43; p = 0.02) but not with changes in BMD. Two patients in the control group with large decreases in BMSi values sustained incident fractures.

CONCLUSION

In patients at increased fracture risk, antiresorptive treatments induced BMD-independent increases in BMSi values, the magnitude of which depended on pretreatment values.

Normative Data for Impact Microindentation for Australian Men: Cross-Sectional Data From the Geelong Osteoporosis Study

Impact microindentation (IMI) is a novel technique for assessing the bone material strength index (BMSi) in vivo. However, no studies have presented normative data for BMSi. The aim of this study was to develop such normative data using a population-based sample of men, randomly selected from electoral rolls for the Barwon Statistical Division in southeastern Australia to participate in the Geelong Osteoporosis Study. BMSi was measured on the tibial plateau using an OsteoProbe in 405 men (ages 33 to 96 years) during the period 2016 to 2019. Associations between BMSi, age, and anthropometry were examined using linear regression models. BMSi values ranged from 49.0 to 100.5. BMSi was negatively correlated with age (r = -0.152, p = 0.002), weight (r = -0.103, p = 0.039), and BMI (r = -0.187, p < 0.001), and positively correlated with height (r = +0.107, p = 0.032). Mean ± SD BMSi was 82.6 ± 7.0 for the whole group, and ranged from 85.6 ± 6.0 for ages 30 to 39 years to 79.8 ± 6.6 for ages 80+ years. This study provides normative data that can be used to calculate T- and Z-scores for BMSi. These data will be useful for identifying men with low BMSi. Further research is warranted to derive optimal cut points for BMSi that discriminate fracture risk. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Management of Osteoporosis in Patients Living With HIV-A Systematic Review and Meta-analysis

OBJECTIVE

Osteoporosis is reported as a common comorbidity in patients living with HIV (PLHIV). The aim of this systematic review and meta-analysis is to assess the evidence on fracture risk in PLHIV, bone mineral density (BMD) in PLHIV compared with controls, longitudinal changes in BMD in PLHIV, and effect of antiosteoporosis treatment in PLHIV.

METHODS

A systematic literature search was conducted using the databases Medline at PubMed and EMBASE using the search terms: "HIV" and "fracture" or "bone turnover," or "bone mineral density." Eligibility criteria followed the aim of the study and include randomized controlled trials and observational studies. Two reviewers extracted the data independently. Meta-analysis was performed using random-effects model assessing fracture risk, BMD compared with controls, and changes in BMD.

RESULTS

One hundred forty-two of 2397 papers identified were included in the systematic review, and subsequently, 84 were included in the meta-analysis. The risks of a fragility fracture [1.51, 95% confidence interval (CI): 1.41 to 1.63] and hip fracture (4.05, 95% CI: 2.99 to 5.49) were increased. PLHIV have lower BMD at the hip (z-score -0.31, 95% CI: -0.46 to -0.27) and lumbar spine (z-score -0.36, 95% CI: -0.39 to -0.15) compared with controls. The reduced BMD did not fully explain the increased fracture risk in PLHIV.

CONCLUSIONS

Current management of osteoporosis in PLHIV follows general osteoporosis guidelines; however, the increased fracture risk is not fully explained by lower BMD, and thus, antiosteoporosis intervention may be beneficial at a higher BMD in PLHIV.

Added Value of Impact Microindentation in the Evaluation of Bone Fragility: A Systematic Review of the Literature

The current gold standard for the diagnosis of osteoporosis and the prediction of fracture risk is the measurement of bone mineral density (BMD) using dual energy x-ray absorptiometry (DXA). A low BMD is clearly associated with increased fracture risk, but BMD is not the only determinant of bone strength, particularly in secondary osteoporosis and metabolic bone disorders in which components other than BMD are affected and DXA often underestimates true fracture risk. Material properties of bone which significantly contribute to bone strength have become evaluable in vivo with the impact microindentation (IMI) technique using the OsteoProbe® device. The question arises whether this new tool is of added value in the evaluation of bone fragility. To this effect, we conducted a systematic review of all clinical studies using IMI in vivo in humans also addressing practical aspects of the technique and differences in study design, which may impact outcome. Search data generated 38 studies showing that IMI can identify patients with primary osteoporosis and fractures, patients with secondary osteoporosis due to various underlying systemic disorders, and scarce longitudinal data also show that this tool can detect changes in bone material strength index (BMSi), following bone-modifying therapy including use of corticosteroids. However, this main outcome parameter was not always concordant between studies. This systematic review also identified a number of factors that impact on BMSi outcome. These include subject- and disease-related factors such as the relationship between BMSi and age, geographical region and the presence of fractures, and technique- and operator-related factors. Taken together, findings from this systematic review confirm the added value of IMI for the evaluation and follow-up of elements of bone fragility, particularly in secondary osteoporosis. Notwithstanding, the high variability of BMSi outcome between studies calls for age-dependent reference values, and for the harmonization of study protocols. Prospective multicenter trials using standard operating procedures are required to establish the value of IMI in the prediction of future fracture risk, before this technique is introduced in routine clinical practice.

Diagnosis, prevention, and treatment of bone fragility in people living with HIV: a position statement from the Swiss Association against Osteoporosis

Life expectancy of people living with HIV (PLWH) is reaching similar length as in the general population. Accordingly, age-related comorbidities, including osteoporosis, are increasing. Fracture risk is higher and increases approximately 10 years earlier in PLWH. Classical risk factors of bone fragility are highly prevalent in PLWH but factors specific for HIV infection itself and the type of antiretroviral therapy (ART) (triple combination antiretroviral therapy) regimen (especially tenofovir and protease inhibitors) also contribute to bone loss. The majority of bone loss occurs during virus activity and at initiation of ART (immune reconstitution) and is associated with an increase of bone resorption (upregulation RANKL). Recent data indicate that calcium and vitamin D supplements as ART initiation lower BMD loss. The reduction of tenofovir plasma concentrations with tenofovir alafenamide attenuates BMD loss but it remains unknown whether it will contribute to reduce fracture risk. Hence, special considerations for the management of bone fragility in PLWH are warranted. Based on the current state of epidemiology and pathophysiology of osteoporosis in PLWH, we provide the consensus of the Swiss Association against Osteoporosis on best practice for diagnosis, prevention, and management of osteoporosis in this population. Periodic assessment of fracture risk is indicated in all HIV patients and general preventive measures should be implemented. All postmenopausal women, men above 50 years of age, and patients with other clinical risk for fragility fractures qualify for BMD measurement. An algorithm clarifies when treatment with bisphosphonates and review of ART regimen in favour of more bone-friendly options are indicated.

Assessment of trabecular bone score, an index of bone microarchitecture, in HIV positive and HIV negative persons within the HIV UPBEAT cohort

Introduction

Increased prevalence of low bone mineral density (BMD) and increased fracture incidence are observed in persons living with HIV (PLWH). The trabecular bone score (TBS) is a novel index of bone microarchitecture which improves fracture prediction independent of BMD.

Methods

The HIV UPBEAT study is a single centre, prospective cohort study that enrolled subjects with and without HIV from similar sociodemographic backgrounds for annual assessments of bone health. TBS was derived from lumbar spine (LS) dual-energy X-ray absorptiometry images. Univariate and multivariable linear regression was used to assess relationships between baseline TBS, BMD, sociodemographic and clinical factors.

Results

463 subjects (201 HIV positive) were included; PLWH were younger and more likely male, of non-African ethnicity and current smokers. HIV was associated with a mean reduction of 0.037 [-0.060, -0.013] (p = 0.002) in TBS. Lower TBS was also associated with male gender, non-African ethnicity, current smoking status and lower LS BMD. HIV remained associated with lower TBS after adjustment for LS BMD, age, gender and ethnicity. However, adjustment for current smoking significantly attenuated the association between HIV and TBS, with further adjustment for higher bone turnover markers largely explaining any residual association. Among the sub-group of PLWH, exposure to protease inhibitors and lower nadir CD4+ T-cell counts were both predictors of lower TBS.

Conclusions

PLWH have lower TBS independent of LS BMD. However, this is largely explained by higher current smoking rates and higher bone turnover in those with HIV. Exposure to PI, but not tenofovir disproxil fumarate, also contributed to lower TBS in those with HIV.

Bone Mineral Density Declines Twice as Quickly Among HIV-Infected Women Compared With Men

BACKGROUND

Initial declines in bone mineral density (BMD) after antiretroviral therapy initiation in HIV are well described, but data on long-term changes and risk factors for decline, particularly among women, are limited.

METHODS

HIV-infected men and women in the Modena Metabolic Clinic underwent dual-energy X-ray absorptiometry (DXA) scans every 6-12 months for up to 10 years (median 4.6 years). Mixed effect regression models in combined and sex-stratified models determined annual rates of decline and clinical factors associated with BMD. Models included demographics, HIV-specific factors, and bone-specific factors; a final model added a sex × time interaction term.

RESULTS

A total of 839 women and 1759 men contributed ≥2 DXA scans. The majority (82%) were 50 years and younger; 76% had HIV-1 RNA <50 copies per milliliter at baseline; 15% of women were postmenopausal and 7% of men had hypogonadism; and 30% and 27%, respectively, had hepatitis C virus (HCV) coinfection. The adjusted slopes in BMD among women and men were significantly different at both the femoral neck (women -0.00897 versus men -0.00422 g/cm per year; P < 0.001) and L-spine (women -0.0127 versus men -0.00763 g/cm per year; P < 0.001). Modifiable risks associated with BMD decline included antiretroviral therapy exposure (greater decline with tenofovir disoproxil fumarate and less decline with integrase strand transfer inhibitor therapy), HCV, physical activity, and vitamin D insufficiency.

CONCLUSIONS

Among HIV-infected individuals, bone density at the femoral neck, a significant predictor of fracture risk, declined twice as quickly among women compared with men. Female sex was independently associated with both lower femoral neck and lumbar BMD over time in adjusted models.

Osteoporosis-Related Fractures in HIV-Infected Patients Receiving Long-Term Tenofovir Disoproxil Fumarate: An Observational Cohort Study

Introduction

Patients with HIV infection may have a higher prevalence of osteoporosis and osteopenia, as well as an increased risk of bone fracture compared with non-HIV-infected individuals. Antiretroviral therapy is thought to be one of factors associated to osteoporosis-related bone fractures.

Objective

The aim of this study was to assess the effects of long-term exposure to tenofovir disoproxil fumarate (TDF) on the cumulative risk of osteoporosis-related bone fractures in Japanese patients with HIV infection.

Design

This observational cohort study comprised a joint HIV-related drug survey of patients treated with TDF between April 2004 and March 2013.

Methods

Thirty-five healthcare facilities in Japan participated in the survey. The incidence of osteoporosis-related fractures was extracted from all adverse events (AEs) using standardized Medical Dictionary for Regulatory Activities queries, and used to calculate the fracture rate per 10,000 patient-years (PY). Kaplan–Meier analysis was used to estimate the cumulative probability of fracture during the study period.

Results

A total of 3251 patients who received TDF or TDF/emtricitabine between April 2004 and March 2013 were analyzed in this study; 93.5% of patients were male. The fracture rate was 13.5 per 10,000 PY in males and 42.2 per 10,000 PY in females. The mean age for male patients with osteoporosis-related fracture was 43.2 years, whereas it was 65.7 years in female patients. The cumulative probability of osteoporosis-related fracture increased after ≥ 5 years of TDF exposure. The rate of hip fracture (95% confidence interval) was 7.2 (3.1–14.2) per 10,000 PY.

Conclusions

Among HIV-infected patients in Japan, treatment with TDF for ≥ 5 years increases the risk of bone fractures in younger men, in addition to that seen in older post-menopausal women.

HIV Infection Is Associated With Abnormal Bone Microarchitecture: Measurement of Trabecular Bone Score in the Women's Interagency HIV Study

OBJECTIVES

We compared skeletal microarchitecture using trabecular bone score (TBS) and evaluated relationships between change in TBS and lumbar spine (LS) bone mineral density (BMD) in women with and without HIV.

METHODS

Dual-energy X-ray absorptiometry was performed on 319 women with HIV and 118 without HIV in the Women's Interagency HIV Study at baseline and 2 and 5 years, to measure regional BMD and lean and fat mass. TBS was extracted from LS dual-energy X-ray absorptiometry images and examined continuously and categorically [normal (≥1.35), intermediate (1.20-1.35), or degraded (≤1.20) microarchitecture]. Pearson correlation and linear regression examined associations of TBS with regional BMD at baseline and over time.

RESULTS

Women with HIV were older (43 vs. 37 years), more likely to be postmenopausal (27% vs. 4%), have lower baseline total fat mass, trunk fat, and leg fat than uninfected women, degraded microarchitecture (27% vs. 9%, P = 0.001), and lower baseline mean TBS (1.3 ± 0.1 vs. 1.4 ± 0.1, P < 0.001). After adjusting for age, race, menopause status, and body mass index, TBS remained lower in women with HIV (P < 0.0001). Annual change in TBS correlated with LS BMD change among women with HIV (r = 0.36, P < 0.0001) and without HIV (r = 0.26, P = 0.02); however, mean % annual TBS change did not differ by HIV status (-1.0%/yr ± 2.9% for HIV+ vs. -0.8%/yr ± 1.7% for HIV-, P = 0.42).

CONCLUSIONS

Women with HIV have worse bone microarchitecture than uninfected women, but annual percent change in LS BMD or TBS was similar. Use of TBS as an adjunct to BMD to improve prediction of fragility fractures in women with HIV merits further study.

The Hidden Burden of Fractures in People Living With HIV

The survival of people living with human immunodeficiency virus (HIV) has increased markedly since the advent of antiretroviral therapy (ART). However, other morbidities have emerged, including osteoporosis. The estimated incidence of fractures at any site in people living with HIV ranges from 0.1 per 1000 person‐years to 8.4 per 1000 person‐years: at least twice that of people without HIV. This increased risk seems to be related to HIV itself and its treatment. Risk factors for bone disease in HIV‐positive (HIV⁺) subjects include both classical risk factors for osteoporosis and fracture and factors linked to HIV itself, such as inflammation, reconstitution syndrome, low CD4, ART, and co‐infection with hepatitis B and C viruses. The risk of fractures in these individuals can be at least partially assessed by measurement of BMD and the Fracture Risk Assessment Tool (FRAX™). Only alendronate and zoledronic acid have been studied in HIV⁺ individuals; both show beneficial effects on BMD, although data on fracture reduction are not available. © 2018 The Authors. JBMR Plus Published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Bone density, microarchitecture, and tissue quality after 1 year of treatment with tenofovir disoproxil fumarate

OBJECIVE

Bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) is used to assess bone health in HIV patients. DXA measures the amount of mineral, but not other key aspects of bone strength such as bone microarchitecture or bone quality. Trabecular bone score (TBS) and in-vivo microindentation directly measure trabecular microarchitecture and bone tissue quality, respectively. The aim of this study is to measure bone strength properties using these techniques.

RESULTS

Forty naive HIV patients who were going to start antiretroviral therapy (ART), a single pill treatment with elvitegravir/cobicistat, tenofovir disoproxil fumarate (TDF), emtricitavine (FTC) were included. A significant reduction in BMD at spine (-3.25%, P < 0.001) and in femoral neck (-3.82%, P = 0.016) between baseline and 48 weeks of treatment were found. Bone microarchitecture score at the spine, as measured by TBS, also significantly decreased from 1.357 (0.09) to 1.322 (0.09) (-2.5%, P = 0.011) between baseline to 48 weeks of treatment. Microindentation (BMSi) values were significantly higher than at baseline [89.04 (4.2) versus 86.07 (6.1); 3.49%, P < 0.001] after 48 weeks of TDF-based ART treatment, indicating improved bone material properties CONCLUSION:: A significant decrease in BMD and TBS were observed after 1 year of TDF therapy. However, tissue quality significantly improved after 1 year of treatment, suggesting a recovery of bone material properties following the control of the infection despite the significant reduction of BMD. These techniques provide additional and necessary information to DXA about bone health in treated HIV patients, and because of its convenience and feasibility they could be routinely apply to assess bone in clinical practice.

Usefulness of the Trabecular Bone Score for assessing the risk of osteoporotic fracture

INTRODUCTION AND OBJECTIVES

The trabecular bone score (TBS) is an imaging technique that assesses the condition of the trabecular microarchitecture. Preliminary results suggest that TBS, along with the bone mineral density assessment, could improve the calculation of the osteoporotic fracture risk. The aim of this study was to analyse TBS values and their relationship with the clinical characteristics, bone mineral density and history of fractures of a cohort of posmenopausal women.

MATERIAL AND METHODS

We analysed 2,257 posmenopausal women from the FRODOS cohort, which was created to determine the risk factors for osteoporotic fracture through a clinical survey and bone densitometry with vertebral morphometry. TBS was applied to the densitometry images. TBS values ≤1230 were considered indicative of degraded microarchitecture. We performed a simple and multiple linear regression to determine the factors associated with this index.

RESULTS

The mean TBS value in L1-L4 was 1.203±0.121. Some 55.3% of the women showed values indicating degraded microarchitecture. In the multiple linear regression analysis, the factors associated with low TBS values were age, weight, height, spinal T-score, glucocorticoid treatment, presence of type 2 diabetes and a history of fractures due to frailty.

CONCLUSIONS

TBS showed microarchitecture degradation values in the participants of the FRODOS cohort and was associated with anthropometric factors, low bone mineral density values, the presence of fractures, a history of type 2 diabetes mellitus and the use of glucocorticoids.