Prospective study of bone mineral density changes in aging men with or at risk for HIV infection

Association of a Polygenic Risk Score With Osteoporosis in People Living With HIV: The Swiss HIV Cohort Study

BACKGROUND

Bone mineral density (BMD) loss may be accelerated in people with HIV (PLWH). It is unknown whether a polygenic risk score (PRS) is associated with low BMD in PLWH.

METHODS

Swiss HIV Cohort Study participants of self-reported European descent underwent ≥2 per-protocol dual x-ray absorptiometry (DXA) measurements ≥2 years apart (2011-2020). Univariable and multivariable odds ratios (ORs) for DXA-defined osteoporosis were based on traditional and HIV-related risk factors and a genome-wide PRS built from 9413 single-nucleotide polymorphisms associated with low BMD in the general population. Controls were free from osteoporosis/osteopenia on all DXA measurements.

RESULTS

We included 438 participants: 149 with osteoporosis and 289 controls (median age, 53 years; 82% male, 95% with suppressed HIV RNA). Participants with unfavorable osteoporosis PRS (top vs bottom quintile) had univariable and multivariable-adjusted osteoporosis ORs of 4.76 (95% CI, 2.34-9.67) and 4.13 (1.86-9.18), respectively. For comparison, hepatitis C seropositivity, 5-year tenofovir disoproxil fumarate exposure, and parent history of hip fracture yielded univariable osteoporosis ORs of 2.26 (1.37-3.74), 1.84 (1.40-2.43), and 1.54 (0.82-2.9).

CONCLUSIONS

In PLWH in Switzerland, osteoporosis was independently associated with a BMD-associated PRS after adjustment for established risk factors, including exposure to tenofovir disoproxil fumarate.

Ageing and older people who use illicit opioids, cocaine or methamphetamine: a scoping review and literature map

AIMS

To provide an overview of research literature on ageing and older people who use illicit opioids and stimulants by documenting the conceptual frameworks used and content areas that have been investigated.

METHODS

We conducted a scoping review of literature relating to ageing and older people who use illicit stimulants and opioids, defining 'older' as 40 years and above. Primary studies, secondary studies and editorials were included. Searches were conducted in PubMed and Embase in July 2020 and March 2021; the Cochrane library was searched in November 2021. Charted data included methodological details, any conceptual frameworks explicitly applied by authors and the content areas that were the focus of the publication. We developed a hierarchy of content areas and mapped this to provide a visual guide to the research area.

RESULTS

Of the 164 publications included in this review, only 16 explicitly applied a conceptual framework. Seven core content areas were identified, with most publications contributing to multiple content areas: acknowledgement of drug use among older people (n = 64), health status (n = 129), health services (n = 109), drug use practices and patterns (n = 84), social environments (n = 74), the criminal legal system (n = 28) and quality of life (n = 15).

CONCLUSIONS

The literature regarding older people who use illicit drugs remains under-theorized. Conceptual frameworks are rarely applied and few have been purposely adapted to this population. Health status and health services access and use are among the most frequently researched topics in this area.

Femoral Neck Fractures in HIV-Positive Patients: Analysis of 10 Years Short-Term Post-operative Complications

Introduction:

Aging and effect of antiretroviral therapy on bone mass could increase the risk of femoral neck fractures (FNF) in HIV patient. The aim of this study was specifically to determine whether intracapsular FNF in HIV-positive patients are more prone to short-term post-operative complications than similar fractures occurring in HIV-negative patients.

Materials and methods:

A group of 25 HIV-positive patients with intracapsular FNF were enrolled and matched to HIV-negative patient with similar fractures according to gender, age, a modified Charlson Comorbidity Index (CCI), fracture classification, surgical treatment and time interval between fracture event and surgery. For each group, length of stay, surgical time, early clinical outcomes and short-term surgical and medical complications were compared to determine the impact on the early outcome.

Results:

At the time of the fracture occurrence, 56% of HIV-positive patients were on antiretroviral therapy and 12% started with therapy in the perioperative period. At three months follow-up, there were no statistically significant differences between the two study groups in length of stay, Harris hip score and total number of early complications. However, a statistically significant increase in urinary tract infections and longer surgical time using hip sliding screw fixation were seen in the HIV-positive group. The poorest post-operative result was seen in a patient who failed to adequately adhere to the HIV therapy protocol.

Conclusions:

This study failed to show any statistically significant increase in short-term complications or worse clinical outcomes for intracapsular FNF in HIV-positive patients compared to HIV-negative patients to recommend their treatment in dedicated centres.

The combined effects of age and HIV on the anatomic distribution of cortical and cancellous bone in the femoral neck among men and women

OBJECTIVE

To investigate HIV-related and age-related differences in hip bone structure in men and women.

DESIGN

Cross sectional study of bone structure and HIV serostatus.

METHODS

We used Quantitative Computed Tomography (QCT) data from the Multicenter AIDS Cohort Study (MACS) and Women's Interagency HIV Study (WIHS) to examine cortical thickness (CT) and cortical (CBMD), trabecular (TBMD), and integral (IBMD) bone mineral density across anatomic quadrants of the femoral neck in older adult MSM and women with (PWH) and without (PWOH) HIV infection. The percentage difference (%diff) in the means for CT and BMD overall and by quadrant between PWH and PWOH were estimated.

RESULTS

Among 322 MSM (median age 60 years) with bone measures, distributions were similar between HIV serostatus groups with %diff in the quadrant means ranging from -7 to -1% for CT and from -1 to 4% for BMD, and overall lower hip cortical thickness than expected. In contrast, in 113 women (median age 51 years), PWH had lower CT, IBMD and TBMD consistently across all quadrants, with differences ranging from -10 to -20% for CT, -6 to -11% for IBMD and -3 to -6% for TBMD. Estimates reached statistical significance in superoanterior quadrant for CT and IBMD and inferoposterior for CT.

CONCLUSION

Among women, PWH appear to have a thinner cortex and less dense integral bone compared with PWOH, particularly in the superior quadrants whereas MSM overall had a thinner than expected hip cortex.

People with HIV infection had lower bone mineral density and increased fracture risk: a meta-analysis

A meta-analysis to investigate the difference in fracture risk between individuals with and without HIV infection was performed. People living with HIV had lower bone mineral density (BMD) and greater risks of overall fractures and fragility fractures. Reducing fragility and maintaining skeletal strength for PLWH are urgently needed for this population.

PURPOSE

The introduction of effective antiretroviral therapy increased the life expectancy of people living with HIV (PLWH). This population now faces problems related to aging such as decreased bone mineral density (BMD) and increased fracture risk. Some antiretroviral therapies may also negatively impact bone health. We performed a meta-analysis to investigate the difference in the fracture risk between individuals with and without HIV infection.

METHODS

We compared BMD, risk of fragility fracture, and risk of all fracture between the two groups. This study included 35 articles with 106,994 PLWH and 228,794,335 controls.

RESULTS

PLWH had lower lumbar spine and hip BMD than controls. PLWH had a higher prevalence of all fracture events (4.08% versus 0.44%) and fragility fractures (2.66% versus 2.19%). The relative risks of all and fragility fractures of PLWH were 1.91 (95% confidence interval (CI), 1.46-2.49; p < 0.001) and 1.68 (95% CI: 1.40-2.01; p < 0.001). PLWH also had more vertebral fractures (1.26% versus 0.37%; RR, 1.97; 95% CI: 1.22-3.2; p < 0.05), hip fractures (1.38% versus 0.81%; RR, 1.88; 95% CI: 0.99-3.57; p = 0.05), and wrist fractures (1.38% versus 1.29%; RR, 1.67; 95% CI: 1.13-2.45; p < 0.05) than healthy controls. The pooled incidence of fractures was 1.72 per 100 person-years in PLWH and 1.29 in healthy controls.

CONCLUSION

PLWH had lower BMD and greater risks of all fractures and fragility fractures. Reducing fragility and maintaining skeletal strength for PLWH are urgently needed for this population.

Alcohol and Bone Turnover Markers among People Living with HIV and Substance Use Disorder

BACKGROUND

Although unhealthy alcohol use and low bone density are prevalent among people living with HIV (PLWH), it is not clear whether alcohol use is associated with bone turnover markers (BTMs), and if so, at what quantity and frequency. The study objective was to examine the association between alcohol and BTMs in PLWH with substance use disorder.

METHODS

We studied a prospective cohort recruited from 2 HIV clinics who met criteria for DSM-IV substance dependence or reported ever injection drug use. Outcomes were BTM of (i) bone formation (serum procollagen type 1 N-terminal propeptide [P1NP]) and (ii) bone resorption (serum C-telopeptide type 1 collagen [CTx]). Alcohol consumption measures included (i) mean number of drinks/d (Timeline Follow-Back [TLFB]) (primary predictor), (ii) any alcohol use on ≥20 of the past 30 days, and phosphatidylethanol (PEth), a biomarker of recent alcohol consumption. Linear regression analysis examined associations between (i) each alcohol measure and each BTM and (ii) change in alcohol and change in BTM over 12 months.

RESULTS

Among 198 participants, baseline characteristics were as follows: The median age was 50 years; 38% were female; 93% were prescribed antiretroviral medications; 13% had ≥20 drinking days/month; mean drinks/day was 1.93 (SD 3.89); change in mean drinks/day was -0.42 (SD 4.18); mean P1NP was 73.1 ng/ml (SD 34.5); and mean CTx was 0.36 ng/ml (SD 0.34). Higher drinks/day was significantly associated with lower P1NP (slope -1.09 ng/ml; 95% confidence interval [CI] -1.94, -0.23, per each additional drink). On average, those who drank on ≥ 20 days/month had lower P1NP (-15.45 ng/ml; 95% CI: -26.23, -4.67) than those who did not. Similarly, PEth level ≥ 8ng/ml was associated with lower P1NP. An increase in drinks/d was associated with a decrease in P1NP nonsignificantly (-1.14; 95% CI: -2.40, +0.12; p = 0.08, per each additional drink). No significant associations were detected between either alcohol measure and CTx.

CONCLUSIONS

In this sample of PLWH with substance use disorder, greater alcohol consumption was associated with lower serum levels of bone formation markers.

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.

Bilateral sequential femoral neck stress fractures in young adult with HIV infection on antiretroviral therapy: A case report

BACKGROUND

Femoral neck stress fractures are rarely encountered among young adults and are often associated with either repetitive excessive loading or underlying bone pathology. Preliminary research has indicated human immunodeficiency virus (HIV)/antiretroviral therapy (ART) as predisposing agents to osteopenia and osteoporosis related complications. We report a case of HIV/ART induced insufficiency fracture in a resource limited setting in Central India. Our aim is to increase awareness and promote screening of HIV/ART related osteopenia and osteoporosis in order to prevent catastrophic orthopaedic complications.

CASE SUMMARY

A 35-year-old HIV positive male presented with a stress fracture of left femoral neck. The patient was on ART and reported no comorbidities. He went on to be successfully managed surgically. However, during work-up osteopenia of the contralateral proximal femur was recognised using Singh’s Index. Six months post-op the patient presented with right-sided femoral - neck stress fracture. At this stage the patient was nonconcordant with ART and denied surgical fixation.

CONCLUSION

In the absence of co-morbidities, several mechanisms of HIV/antiretroviral therapy may have played a role in predisposing our patient towards such a presentation. We recommend routine screening all HIV-infected patients for osteopenia, especially in younger individuals. In low resource settings and district hospitals, pelvis radiograph & Singh’s index can be used for screening.

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.

Zoledronic acid is superior to tenofovir disoproxil fumarate-switching for low bone mineral density in adults with HIV

OBJECTIVE

To compare the effects of switching tenofovir disoproxil fumarate (TDF) or treatment with an intravenous bisphosphonate on bone mineral density (BMD) in HIV-positive adults with low bone mass.

DESIGN

Two-year, randomized, open-label study at 10 sites in Australia and Spain.

PARTICIPANTS

Of 112 adults on TDF-based antiretroviral therapy (ART) screened, 87 with low BMD (T-score < -1.0 at hip or spine by dual-energy X-ray absorptiometry) and undetectable plasma HIV viral load were randomized to either switch TDF to another active antiretroviral drug or to continue TDF-based ART and receive intravenous zoledronic acid (ZOL) 5 mg annually for 2 years.

PRIMARY OUTCOME MEASURE

Change in lumbar spine BMD at 24 months by intention-to-treat analysis. Secondary outcomes included changes in femoral neck and total hip BMD, fractures, safety, and virological failure.

RESULTS

Forty-four participants were randomized to TDF switch and 43 to ZOL, mean age 50 years (SD 11), 96% men, mean TDF duration 5.9 years (SD 3.1), and mean spine and hip T-scores -1.6 and -1.3, respectively. At 24 months, mean spine BMD increased by 7.4% (SD 4.3%) with ZOL vs. 2.9% (SD 4.5%) with TDF-switch (mean difference 4.4%, 95% CI 2.6-6.3; P < 0.001). Mean total hip BMD increased by 4.6 (SD 2.6%) and 2.6% (SD 4%), respectively (mean difference 1.9%, 95% CI 0.5-3.4; P = 0.009). There was one fracture in the ZOL group vs. seven fractures in four TDF-switch participants. Virological failure occurred in one TDF-switch participant. Other safety endpoints were similar.

CONCLUSION

ZOL is more effective than switching TDF at increasing BMD in HIV-positive adults with low bone mass.

Alcohol Consumption and Bone Mineral Density in People with HIV and Substance Use Disorder: A Prospective Cohort Study

BACKGROUND

People living with HIV (PLWH) commonly have low bone mineral density (BMD) (low bone mass and osteoporosis) and are at high risk for fractures. Fractures and low BMD are significant causes of morbidity and mortality, increasingly relevant as PLWH age. Alcohol use is common among PLWH and known to affect bone health. The association between alcohol use and changes in BMD among PLWH is not well understood.

METHODS

We conducted a 3.5-year prospective cohort study of 250 PLWH with substance use disorder or ever injection drug use. Annual alcohol consumption was measured as a mean of grams per day of alcohol, mean number of heavy drinking days per month, mean number of days abstinent per month, and any heavy drinking, using the 30-day Timeline Followback method twice each year. The primary outcome was annual change in BMD measured each year by dual energy X-ray absorptiometry in grams per square centimeter (g/cm2 ) at the femoral neck. Additional dependent variables included annual change in total hip and lumbar spine BMD, >6% annual decrease in BMD at any site, and incident fractures in the past year. Regression models adjusted for relevant covariates.

RESULTS

The median age of participants was 50 years. The median duration of HIV infection was 16.5 years and the mean time since antiretroviral therapy initiation was 12.3 years. At study entry, 67% of participants met criteria for low BMD (46% low bone mass, 21% osteoporosis). Median follow-up was 24 months. We found no significant associations between any measure of alcohol consumption and changes in BMD (g/cm2 ) at the femoral neck (adjusted β for g/d of alcohol = -0.0032, p = 0.7487), total hip, or lumbar spine. There was no significant association between any measure of alcohol consumption and >6% annual decrease in BMD at any site, or incident fractures.

CONCLUSIONS

In this sample of PLWH and substance use disorders or ever injection drug use, we detected no association between any of the alcohol measures used in the study and changes in BMD or incident fractures.

Prevalence and risk factors for low bone mineral density in antiretroviral therapy-naive HIV-infected young men

OBJECTIVE

We aimed to investigate the prevalence of low bone mineral density (BMD) and associated factors in antiretroviral therapy (ART)-naive HIV-infected young men.

METHODS

In this cross-sectional study, dual-energy X-ray absorptiometry (DXA) was used to measure BMD. BMD at the lumbar spine, total hip and femoral neck sites was expressed as a Z-score (number of standard deviations away from the mean in an age, race and sex-matched reference population). Low BMD was defined as Z-scores≤-2 at any of the three sites. The prevalence of low BMD was evaluated at the lumbar spine, total hip and femoral neck sites, as were risk factors associated with Z-scores.

RESULTS

The study cohort comprised 49 men, of whom 87.8% were white. Mean age was 31.6 (±7.7) years and mean BMI was 22.7 (±4.0)kg/m². Half of patients (51.0%) were current smokers. The prevalence of low BMD was 24.5% [95% CI, 13.3-38.9]. Low estradiol levels and low BMI were associated with low Z-scores at each skeletal site, whereas current smoking and high IGF1 levels were associated with low Z-scores at the lumbar spine site. Among the HIV-related factors, low CD4+ cell count was associated with low Z-scores at the lumbar spine site.

CONCLUSIONS

We observed a high prevalence of low BMD in our ART-naive cohort of young men. Risk factors associated with low Z-scores were those usually observed in HIV-infected individuals (low BMI, current smoking and CD4+ cell count) or linked to endocrine hormone levels (estradiol, IGF-1).

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.

Homeostatic Expansion of CD4+ T Cells Promotes Cortical and Trabecular Bone Loss, Whereas CD8+ T Cells Induce Trabecular Bone Loss Only

Background

Bone loss occurs in human immunodeficiency virus (HIV) infection but paradoxically is intensified by HIV-associated antiretroviral therapy (ART), resulting in an increased fracture incidence that is largely independent of ART regimen. Inflammation in the bone microenvironment associated with T-cell repopulation following ART initiation may explain ART-induced bone loss. Indeed, we have reported that reconstitution of CD3+ T cells in immunodeficient mice mimics ART-induced bone loss observed in humans. In this study, we quantified the relative effects of CD4+ and CD8+ T-cell subsets on bone.

Methods

T-cell subsets in T-cell receptor β knockout mice were reconstituted by adoptive transfer with CD4+ or CD8+ T-cells subsets were reconstituted in T-cell receptor β knockout mice by adoptive transfer, and bone turnover, bone mineral density, and indices of bone structure and turnover were quantified.

Results

Repopulating CD4+ but not CD8+ T cells significantly diminished bone mineral density. However, micro-computed tomography revealed robust deterioration of trabecular bone volume by both subsets, while CD4+ T cells additionally induced cortical bone loss.

Conclusions

CD4+ T-cell reconstitution, a key function of ART, causes significant cortical and trabecular bone loss. CD8+ T cells may further contribute to trabecular bone loss in some patients with advanced AIDS, in whom CD8+ T cells may also be depleted. Our data suggest that bone densitometry used for assessment of the condition of bone in humans may significantly underestimate trabecular bone damage sustained by ART.

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.

Lifetime and recent alcohol use and bone mineral density in adults with HIV infection and substance dependence

Low bone mineral density (BMD) is common in people living with HIV infection (PLWH), increasing fracture risk. Alcohol use is also common in PLWH and is a modifiable risk factor for both HIV disease progression and low BMD. In PLWH, alcohol's effect on BMD is not well understood.We studied adult PLWH with substance dependence. We measured lifetime alcohol use (kg) and recent (i.e., past 30-day) alcohol use (categorized as: abstinent, low risk, or high risk). In adjusted multivariable regression analyses, we tested associations between lifetime and recent alcohol use and (i) mean BMD (g/cm) at the femoral neck, total hip, and lumbar spine and (ii) low BMD diagnosis (i.e., osteopenia or osteoporosis). We also examined associations between 2 measures of past alcohol use (i.e., total consumption [kg] and drinking intensity [kg/year]) and BMD outcome measures during 3 periods of the HIV care continuum: (i) period before first positive HIV test, (ii) period from first positive HIV test to antiretroviral therapy (ART) initiation, and (iii) period following ART initiation.We found no significant associations between lifetime alcohol use and mean femoral neck (β -0.000, P = .62), total hip (β -0.000, P = .83) or lumbar spine (β 0.001, P = .65) BMD (g/cm), or low BMD diagnosis (adjusted odds ratio [aOR] = 0.98, 95% Confidence Interval [CI]: 0.95-1.01). There was no significant correlation between past 30-day alcohol use and mean BMD (g/cm). Past 30-day alcohol use was associated with low BMD diagnosis (P = .04); compared to abstainers, the aOR for high risk alcohol use was 1.94 (95% CI: 0.91-4.12), the aOR for low risk alcohol use was 4.32 (95% CI: 1.30-14.33). Drinking intensity (kg/year) between first positive HIV test and ART initiation was associated with lower mean BMD (g/cm) at the femoral neck (β -0.006, P = .04) and total hip (β -0.007, P = .02) and increased odds of low BMD (aOR = 1.18, 95% CI = 1.03-1.36).In this sample of PLWH, we detected no association between lifetime alcohol use and BMD. However, recent drinking was associated with low BMD diagnosis, as was drinking intensity between first positive HIV test and ART initiation. Longitudinal studies should confirm these associations.

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.

Physiological and pathophysiological bone turnover - role of the immune system

Osteoporosis develops when the rate of osteoclastic bone breakdown (resorption) exceeds that of osteoblastic bone formation, which leads to loss of BMD and deterioration of bone structure and strength. Osteoporosis increases the risk of fragility fractures, a cause of substantial morbidity and mortality, especially in elderly patients. This imbalance between bone formation and bone resorption is brought about by natural ageing processes, but is frequently exacerbated by a number of pathological conditions. Of importance to the aetiology of osteoporosis are findings over the past two decades attesting to a deep integration of the skeletal system with the immune system (the immuno-skeletal interface (ISI)). Although protective of the skeleton under physiological conditions, the ISI might contribute to bone destruction in a growing number of pathophysiological states. Although numerous research groups have investigated how the immune system affects basal and pathological osteoclastic bone resorption, recent findings suggest that the reach of the adaptive immune response extends to the regulation of osteoblastic bone formation. This Review examines the evolution of the field of osteoimmunology and how advances in our understanding of the ISI might lead to novel approaches to prevent and treat bone loss, and avert fractures.

Hepatitis C virus coinfection as a risk factor for osteoporosis and fracture

PURPOSE OF REVIEW

With increased survival of HIV-infected patients, osteoporotic fractures have developed as a major cause of morbidity in these patients, and chronic hepatitis C virus (HCV) coinfection has emerged as a significant contributor to this increased fracture risk. The present article reviews the epidemiologic and clinical evidence for osteoporosis and increased fracture risk among HIV/HCV coinfected patients, and potential mechanisms for these outcomes with HCV coinfection.

RECENT FINDINGS

Epidemiologic studies suggest that HIV/HCV coinfected patients exhibit a three-fold increased fracture incidence compared with uninfected controls, and 1.2-2.4-fold increased fracture risk compared with HIV monoinfected patients. Recent reports suggest that chronic HCV coinfection is independently associated with reduced bone mineral density in HIV, but that it is not associated with significantly increased bone turnover. The deleterious impact of chronic HCV on BMD and fracture risk occurs even in the absence of advanced liver fibrosis or cirrhosis. New tools to assess bone quality, including the trabecular bone score, high-resolution peripheral quantitative computed tomography, and in-vivo microindentation, may help improve understanding of the mechanisms of HCV-associated skeletal fragility. The impact of approved antiosteoporosis medications and direct-acting antivirals for the treatment of chronic HCV infection on patients' bone health remain to be studied.

SUMMARY

Chronic HCV infection is an independent risk factor for osteoporosis and fractures among HIV-infected patients, even before the development of cirrhosis. The underlying mechanisms are being unraveled, but major questions persist regarding the optimal evaluation and management of bone health in HIV/HCV coinfected patients.

Antiretroviral therapy induces a rapid increase in bone resorption that is positively associated with the magnitude of immune reconstitution in HIV infection

OBJECTIVE

Antiretroviral therapy (ART) paradoxically intensifies bone loss in the setting of HIV infection. Although the extent of bone loss varies, it occurs with virtually all ART types, suggesting a common pathway that may be aligned with HIV disease reversal. Using an animal model of immunodeficiency we recently demonstrated that immune activation associated with CD4 T-cell reconstitution induces increased production of the osteoclastogenic cytokines RANKL and TNFα by immune cells, driving enhanced bone resorption and loss in bone mineral density.

DESIGN

To confirm these findings in humans, we investigated the early kinetics of CD4 T-cell recovery in relation to biomarkers of bone turnover and osteoclastogenic regulators in a prospective 24-week cohort study.

METHODS

Clinical data and blood sampling for HIV-RNA PCR, CD4 T-cell counts, bone turnover biomarkers, and osteoclastogenic regulators were obtained from ART-naïve HIV-infected study participants initiating standard doses of lopinavir/ritonavir plus tenofovir disoproxil fumarate/emtricitabine at baseline and at weeks 2, 8, 12, and 24 post ART.

RESULTS

C-terminal telopeptide of collagen (CTx) a sensitive biomarker of bone resorption rose by 200% above baseline at week 12, remaining elevated through week 24 (α<0.01), and was associated with significant increases in plasma levels of osteoclastogenic regulators [receptor activator of NF-kB ligand (RANKL), tumor necrosis factor alpha, (TNFα)]. Importantly, the magnitude of CD4 T-cell recovery correlated significantly with CTx (rs = 0.387, α=0.01).

CONCLUSION

Our data suggest that ART-induced bone loss occurs early, is aligned with early events of immune reconstitution, and these immune changes provide a unifying mechanism to explain in part the skeletal decline common to all ART.

Role of T-cell reconstitution in HIV-1 antiretroviral therapy-induced bone loss

HIV infection causes bone loss. We previously reported that immunosuppression-mediated B-cell production of receptor activator of NF-κB ligand (RANKL) coupled with decline in osteoprotegerin correlate with decreased bone mineral density (BMD) in untreated HIV infection. Paradoxically, antiretroviral therapy (ART) worsens bone loss although existing data suggest that such loss is largely independent of specific antiretroviral regimen. This led us to hypothesize that skeletal deterioration following HIV disease reversal with ART may be related to T-cell repopulation and/or immune reconstitution. Here we transplant T cells into immunocompromised mice to mimic ART-induced T-cell expansion. T-cell reconstitution elicits RANKL and TNFα production by B cells and/or T cells, accompanied by enhanced bone resorption and BMD loss. Reconstitution of TNFα- or RANKL-null T-cells and pharmacological TNFα antagonist all protect cortical, but not trabecular bone, revealing complex effects of T-cell reconstitution on bone turnover. These findings suggest T-cell repopulation and/or immune reconstitution as putative mechanisms for bone loss following ART initiation.

Hemin activation of innate cellular response blocks human immunodeficiency virus type-1-induced osteoclastogenesis

The normal skeletal developmental and homeostatic process termed osteoclastogenesis is exacerbated in numerous pathological conditions and causes excess bone loss. In cancer and HIV-1-infected patients, this disruption of homeostasis results in osteopenia and eventual osteoporesis. Counteracting the factors responsible for these metabolic disorders remains a challenge for preventing or minimizing this co-morbidity associated with these diseases. In this report, we demonstrate that a hemin-induced host protection mechanism not only suppresses HIV-1 associated osteoclastogenesis, but it also exhibits anti-osteoclastogenic activity for non-infected cells. Since the mode of action of hemin is both physiological and pharmacological through induction of heme oxygenase-1 (HO-1), an endogenous host protective response to an FDA-licensed therapeutic used to treat another disease, our study suggests an approach to developing novel, safe and effective therapeutic strategies for treating bone disorders, because hemin administration in humans has previously met required FDA safety standards.

Effects of Emtricitabine/Tenofovir on Bone Mineral Density in HIV-Negative Persons in a Randomized, Double-Blind, Placebo-Controlled Trial

BACKGROUND

Daily preexposure prophylaxis (PrEP) with oral emtricitabine and tenofovir disoproxil fumarate (FTC/TDF) decreases the risk of human immunodeficiency virus (HIV) acquisition. Initiation of TDF decreases bone mineral density (BMD) in HIV-infected people. We report the effect of FTC/TDF on BMD in HIV-seronegative men who have sex with men and in transgender women.

METHODS

Dual-energy X-ray absorptiometry was performed at baseline and 24-week intervals in a substudy of iPrEx, a randomized, double-blind, placebo-controlled trial of FTC/TDF PrEP. Plasma and intracellular tenofovir concentrations were measured in participants randomized to FTC/TDF.

RESULTS

In 498 participants (247 FTC/TDF, 251 placebo), BMD in those randomized to FTC/TDF decreased modestly but statistically significantly by 24 weeks in the spine (net difference, -0.91% [95% confidence interval {CI}, -1.44% to -.38%]; P = .001) and hip (-0.61% [95% CI, -.96% to -.27%], P = .001). Changes within each subsequent 24-week interval were not statistically significant. Changes in BMD by week 24 correlated inversely with intracellular tenofovir diphosphate (TFV-DP), which was detected in 53% of those randomized to FTC/TDF. Net BMD loss by week 24 in participants with TFV-DP levels indicative of consistent dosing averaged -1.42% ± 29% and -0.85% ± 19% in the spine and hip, respectively (P < .001 vs placebo). Spine BMD tended to rebound following discontinuation of FTC/TDF. There were no differences in fractures (P = .62) or incidence of low BMD.

CONCLUSIONS

In HIV-uninfected persons, FTC/TDF PrEP was associated with small but statistically significant decreases in BMD by week 24 that inversely correlated with TFV-DP, with more stable BMD thereafter.

CLINICAL TRIALS REGISTRATION

NCT00458393.

Soluble CD163 is associated with shortened telomere length in HIV-infected patients

Telomere length (TL) and immune activation markers were measured in a cohort of HIV-infected (n = 102) and age-matched non-HIV-infected (n = 41) men. TL was significantly shorter in HIV-infected compared with non-HIV-infected subjects (P = 0.04). Univariate analysis revealed a strong inverse relationship of TL to sCD163, and thus, monocyte/macrophage activation, among the HIV group (ρ = -0.30, P = 0.003). In multivariate modeling among the whole group, HIV-positive serostatus (P = 0.06) and sCD163 (P = 0.05) remained predictors of TL controlling for age and smoking status. Our data demonstrate that increased immune activation relates to shorter TL in HIV.

Skeletal health in adults with HIV infection

Concern has been raised that HIV infection, its treatment, or both adversely affect skeletal health. Cross-sectional studies show that bone mineral density (BMD) is 3-5% lower in patients infected with HIV than in uninfected controls, but patients with HIV infection are, on average, 5 kg lighter than uninfected people. After this weight difference is accounted for, BMD differences are smaller and not clinically relevant. Longitudinal studies show short-term BMD loss of 2-4% over 1-2 years when antiretroviral therapy is started, followed by longer periods of BMD increase or stability. Losses are greatest with treatment regimens that contain tenofovir. Patients infected with HIV have slightly higher fracture rates than controls, but the increased risk of fracture is substantially attenuated by adjustment for traditional risk factors for fracture. These reassuring findings suggest that management of skeletal health in HIV should follow guidelines for the general population. In general, effective antiretroviral treatment and avoidance of undernutrition are the two most important factors for maintenance of skeletal health in patients infected with HIV.

Effect of risedronate in osteoporotic HIV males, according to gonadal status: a pilot study

The aim of the study was to evaluate the effect of risedronate on bone mineral density (BMD) and bone turnover markers in HIV-infected osteoporotic males, according to their gonadal status. HIV patients were followed up for 24 months and divided into two groups: patients with osteoporosis or osteopenia with fractures (group A, n = 20) and those without (group B, n = 21). Group A and B were further divided according to the presence of reduced androgenizations. Both groups were treated with cholecalciferol 800 I.U. and calcium (Ca) 1,000 mg orally every day for the first 12 months. Risedronate 75 mg for two consecutive days a month orally was then added in group A, for another 12 months. Group B continued treatment with Ca and vitamin D. Every 6 months each patient underwent biochemical evaluation, and BMD measurement. A significant increase in lumbar BMD was observed in HIV males with adequate androgenization after 12 months of risedronate treatment in group A together with a reduction of bone turnover markers. BMD remained stable with a concomitant significant slight reduction of bone turnover markers in group B. Risedronate increased BMD and reduced bone turnover markers to a greater extent in patients with adequate androgenization compared to osteoporotic HIV males with symptomatic hypoandrogenization.

Osteoporosis and fractures in HIV/hepatitis C virus coinfection: a systematic review and meta-analysis

OBJECTIVE

There is growing evidence that fracture risk is increased in individuals with HIV and/or hepatitis C virus (HCV) infection. We systematically reviewed the literature to determine whether prevalence of osteoporosis and incidence of fracture is increased in HIV/HCV-coinfected individuals.

DESIGN

A systematic review and meta-analysis.

METHODS

A search was performed of Medline, Scopus and the Cochrane Library databases, as well as of abstracts from annual retroviral, liver and bone meetings (up to 2013) for studies with bone mineral density (BMD) or bone fracture data for HIV/ HCV-coinfected individuals. Osteoporosis odds ratios (ORs) and fracture incidence rate ratios (IRRs) were estimated from studies with data on HIV-monoinfected or HIV/HCV uninfected comparison groups.

RESULTS

Of 15 included studies, nine reported BMD data and six reported fracture data. For HIV/HCV-coinfected, the estimated osteoporosis prevalence was 22% [95% confidence interval (95% CI) 12–31] and the crude OR for osteoporosis compared with HIV-monoinfected was 1.63 (95% CI 1.27-2.11). The pooled IRR of overall fracture risk for HIV/HCV-coinfected individuals was 1.77 (95% CI 1.44-2.18) compared with HIV-monoinfected and 2.95 (95% CI 2.17-4.01) compared with uninfected individuals. In addition to HIV/HCV-coinfection, older age, lower BMI, smoking, alcohol and substance use were significant predictors of osteoporosis and fractures across studies.

CONCLUSION

HIV/HCV coinfection is associated with a greater risk of osteoporosis and fracture than HIV monoinfection; fracture risk is even greater than uninfected controls. These data suggest that HIV/HCV-coinfected individuals should be targeted for fracture prevention through risk factor modification at all ages and DXA screening at age 50.

Relative contribution of HIV infection, demographics and body mass index to bone mineral density

INTRODUCTION

Low bone mineral density (BMD) is common in HIV-positive patients, although the role played by HIV infection versus sociodemographic and metabolic factors remains unclear.

METHODS

Understanding the Pathology of Bone Disease in HIV-infected individuals (HIV UPBEAT) is a prospective cohort study, enrolled HIV-positive and HIV-negative participants from similar demographic backgrounds. Dual X-ray absorptiometry at femoral neck, total hip and lumbar spine and blood tests were performed. Associations between BMD and factors of interest were assessed using multivariable linear regression.

RESULTS

A total of 474 participants were recruited. Two hundred and ten were HIV-positive, of whom, 59% were male, 40% African and median (interquartile range) age was 39 (33, 46) years. HIV acquisition risks were heterosexual sex (46.9%), homosexual sex (25.4%) and intravenous drug use (18.7%). Of the HIV-negative participants, 44% were male, 25% were African and median (interquartile range) age was 42 (34-49) years. HIV infection was independently associated with a 0.062 (P < 0.0001), 0.078 (P < 0.0001) and 0.060 g/cm (P =  0.0002) lower BMD at femoral neck, total hip and lumbar spine, respectively, after adjustment for demographic/ lifestyle factors and BMI. After further adjustment for bone biomarkers, HIV remained independently associated with reduced BMD at each site, although effect sizes were reduced. The HIV-positive group had significantly higher bone turnover (all between-group P < 0.0001). Treatment variables and cumulative exposure to antiretroviral therapy were not associated with lower BMD at femoral neck or total hip, but acquisition of HIV infection via intravenous drug use and longer time since HIV diagnosis were independently associated with lower lumbar spine BMD.

DISCUSSION

HIV is independently associated with lower BMD, and its effect is likely mediated, in part, by alterations in bone metabolism.

Is bone loss linked to chronic inflammation in antiretroviral-naive HIV-infected adults? A 48-week matched cohort study

OBJECTIVE

Antiretroviral therapy (ART) has been implicated in bone loss in HIV. The role of inflammation and vitamin D is unclear and better investigated in ART-naive individuals.

DESIGN AND METHODS

This is a 48-week, prospective cohort study to compare baseline and change in hip and spine bone mineral density (BMD) measured by dual-energy X-ray absorptiometry in HIV-infected, ART-naive adults and healthy controls matched by age, sex, and race. We also studied associations between bone loss and inflammation markers and plasma 25-hydroxyvitamin D [25(OH)D] using logistic regression.

RESULTS

Forty-seven HIV-infected adults and 41 controls were included. Baseline 25(OH)D, BMD at total hip, trochanter, and spine, and prevalence of osteopenia and osteoporosis were similar between groups. In the HIV-infected group, total hip and trochanter, but not spine, BMD decreased over 48 weeks [hip -0.005 (-0.026-0.008) g/cm², P = 0.02 within group; trochanter -0.013 (-0.03-0.003), P < 0.01]. BMD did not change at any site within controls. The HIV-infected group was more likely to have bone loss at the trochanter (P = 0.03). This risk persisted after adjustment for age, sex, race, BMI, smoking, and hepatitis C (odds ratio 4, 95% confidence interval 1.2-15.8). In the HIV-infected group, higher interleukin-6 concentrations (P = 0.04) and Caucasian race (P < 0.01) were independently associated with progression to osteopenia or osteoporosis, but not 25(OH)D levels.

CONCLUSION

BMD at the total hip and trochanter sites decreased in the HIV-infected, ART-naive adults, but not controls, over this 48-week study. Higher serum interleukin-6 concentrations were associated with progression to osteopenia or osteoporosis status in the HIV-infected group.

Surgery of the femur in HIV positive patients: a retrospective review from 2005 to 2011

BACKGROUND

There are an estimated 6,900 people with HIV living in Ireland. There is a significant prevalence of femoral osteonecrosis and risk factors for osteoporotic fractures. With this potential, increasing surgical workload, it is important to assess surgical demand and audit outcomes.

METHODS

The hospital's electronic records were examined. Between January 2005 and August 2011, 17 femoral surgeries were identified in seven patients. Patient records were retrospectively reviewed.

RESULTS

Elective operations undertaken were eight hip replacements and one nail dynamisation. Eight emergency operations were undertaken: two DHS, one plating, one nailing, one revision nailing, two incision and drainages and one biopsy. All procedures were carried out using appropriate safety guidelines. Indications for surgery included femoral head osteonecrosis (n = 7), osteomyelitis (n = 3), proximal femoral fracture (n = 2), femoral shaft non-union (n = 1), dynamisation of a nail (n = 1), osteoarthritis (n = 1), fractured femur (n = 1), and revision nailing (n = 1). For two procedures the patient was not on highly active anti-retroviral treatment. All elective patients had CD4 counts greater than 200 pre-operatively. Six patients had undetectable viral loads. Of the eight emergency procedures, four procedures had no preoperative immune status recorded. Complications recorded were three non-unions, one nail fracture, one lesser trochanter fracture and recurrence of osteomyelitis. No surgical site infections were recorded.

CONCLUSIONS

Complications were not related to immune status. The rate of surgical site infection in both elective and emergency procedures was low. The elective surgery patients can safely receive orthopaedic treatment in their regional orthopaedic unit. Due to the high non-infectious complication rates recorded in the emergency group, transfer to a tertiary facility with infectious disease expertise is advised.

Effects of smoking on non-AIDS-related morbidity in HIV-infected patients

Tobacco smoking has many adverse health consequences. Patients with human immunodeficiency virus (HIV) infection smoke at very high rates, and many of the comorbidities associated with smoking in the general population are more prevalent in this population. It is likely that a combination of higher smoking rates along with an altered response to cigarette smoke throughout the body in persons with HIV infection leads to increased rates of the known conditions related to smoking. Several AIDS-defining conditions associated with smoking have been reviewed elsewhere. This review aims to summarize the data on non-AIDS-related health consequences of smoking in the HIV-infected population and explore evidence for the potential compounding effects on chronic systemic inflammation due to HIV infection and smoking.

Time of progression to osteopenia/osteoporosis in chronically HIV-infected patients: screening DXA scan

BACKGROUND

Algorithms for bone mineral density (BMD) management in HIV-infected patients are lacking. Our objective was to assess how often a dual-energy x-ray absorptiometry (DXA) scan should be performed by assessing time of progression to osteopenia/osteoporosis.

METHODS

All DXA scans performed between 2000 and 2009 from HIV-infected patients with at least two DXA were included. Time to an event (osteopenia and osteoporosis) was assessed using the Kaplan-Meier method. Strata (tertiles) were defined using baseline minimum T scores. Differences between strata in time to an event were compared with the log-rank test.

RESULTS

Of 391 patients (1,639 DXAs), 49.6% had osteopenia and 21.7% osteoporosis at their first DXA scan. Of the 112 (28.6%) with normal BMD, 35.7% progressed to osteopenia; median progression time was 6.7 years. These patients were stratified: "low-risk" (baseline minimum T score >-0.2 SD), "middle-risk" (between -0.2 and -0.6 SD), and "high-risk" (from -0.6 to -1 SD); median progression time to osteopenia was 8.7, >7.2, and 1.7 years, respectively (p<0.0001). Of patients with osteopenia, 23.7% progressed to osteoporosis; median progression time was >8.5 years. Progression time was >8.2 years in "low-risk" tertile (T score between -1.1 and -1.6 SD), >8.5 years in "middle-risk" (between -1.6 and -2), and 3.2 years in "high-risk" (from -2 to -2.4) (p<0.0001).

CONCLUSIONS

Our results may help to define the BMD testing interval. The lowest T score tertiles would suggest recommending a subsequent DXA in 1-2 years; in the highest tertiles, ≥6 years. Early intervention in patients with bone demineralization could reduce fracture-related morbidity/mortality.

Dairy calcium intake and lifestyle risk factors for bone loss in hiv-infected and uninfected Mediterranean subjects

BACKGROUND

Despite the reported high prevalence of osteoporosis in the human immunodeficiency virus (HIV)-population, there have been no previous studies examining dairy calcium intake and bone mineral density (BMD) in HIV-subjects. We assessed the prevalence of low BMD in HIV-infected and uninfected subjects and analyzed the effects of calcium intake, lifestyle and HIV-related risk factors on BMD.

METHODS

One hundred and twelve HIV-infected subjects were consecutively enrolled. Seventy- six HIV-uninfected subjects matched for age and sex were enrolled as the control group. The HIV-subjects were interviewed about lifestyle habits and completed a weekly food-frequency questionnaire to estimate calcium intake. HIV-RNA, CD4+ T-cell count and data on antiretroviral therapy were also recorded. Both biochemical bone turnover markers and BMD, assessed by dual-energy radiographic absorptiometry (DXA) were recorded in the HIV-cases and controls. We also calculated the 10-year fracture risks using the WHO FRAX equation.

RESULTS

Osteoporosis prevalence was significantly higher in the HIV-cases than controls (p < 0.05). BMI values were positively correlated with BMD (p < 0.05). Vitamin D levels were lower in the HIV-subjects (p < 0.02). No correlation was found with daily calcium intake. BMI values were significantly correlated with dairy intake quartiles (p < 0.003). In HIV-subjects, the mean of FRAX score was 1.2 % for hip and 4.7 % for major osteoporotic fractures. On multivariate analysis of the lumbar spine DXA T-score, age (p < 0.005) and HIV/hepatitis C virus co-infection (p < 0.0001) were negatively correlated with BMD, while yogurt intake was a protective predictor of BMD (p < 0.05). In the femur DXA T-score, age (p < 0.01), nadir CD4 + T-cell count < 200 cells/μL (p < 0.05) and drug addiction ( p < 0.0001) were negatively correlated with BMD.

CONCLUSIONS

Among the foods rich in calcium, yogurt was a protective predictor of BMD in HIV-subjects. HIV/HCV co-infection, nadir CD4 + T-cell count < 200 cells/μL and drug addiction were independent predictors of severe BMD. Promoting behavioral changes in food intake and lifestyle, aimed at the primary prevention of bone disease in the chronically-infected subjects seems to be essential for implementing medical intervention in these cases.

Low bone mass in behaviorally HIV-infected young men on antiretroviral therapy: Adolescent Trials Network Study 021B

BACKGROUND

Peak bone mass is achieved in adolescence/early adulthood and is the key determinant of bone mass in adulthood. We evaluated the association of bone mass with human immunodeficiency virus (HIV) infection and antiretroviral therapy (ART) during this critical period among behaviorally HIV-infected young men and seronegative controls.

METHODS

HIV-positive men (N = 199) and HIV-negative controls (N = 53), ages 14-25 years, were studied at 15 Adolescent Trials Network for HIV/AIDS Interventions sites. HIV-positive participants were recruited on the basis of ART status: ART-naive (N = 105) or on a regimen containing a nonnucleoside reverse transcriptase inhibitor (NNRTI; N = 52) or protease inhibitor (PI; N = 42). Bone mineral density (BMD) and content (BMC) and body composition were measured by dual-energy X-ray absorptiometry (DXA). Results were compared across groups by linear modeling. Bone results were adjusted for race, body mass index (BMI), and type of DXA (Hologic/Lunar).

RESULTS

The HIV-positive and HIV-negative groups had comparable median age (21 years) and racial/ethnic distribution. Median times since HIV diagnosis were 1.3, 1.9, and 2.2 years in the ART-naive, NNRTI, and PI groups, respectively (P = .01). Total and regional fat were significantly lower in the ART-naive group compared with seronegative controls. Mean BMD and Z scores were generally lower among HIV-positive participants on ART, particularly in the PI group. Average Z scores for the spine were below zero in all 4 groups, including controls.

CONCLUSIONS

Young men on ART with a relatively recent diagnosis of HIV infection have lower bone mass than controls. Longitudinal studies are required to determine the impact of impaired accrual or actual loss of bone during adolescence on subsequent fracture risk.

HIV infection and older Americans: the public health perspective

HIV disease is often perceived as a condition affecting young adults. However, approximately 11% of new infections occur in adults aged 50 years or older. Among persons living with HIV disease, it is estimated that more than half will be aged 50 years or older in the near future. In this review, we highlight issues related to HIV prevention and treatment for HIV-uninfected and HIV-infected older Americans, and outline unique considerations and emerging challenges for public health and patient management in these 2 populations.

HIV: inflammation and bone

HIV infection and antiretroviral therapy (ART) are now established independent risk factors for osteoporosis. With a spate of recent studies reporting significant elevations in fracture prevalence in HIV patients, and a rapidly aging demographic, defining the mechanisms underlying HIV/ART-induced skeletal decline has become imperative. The recent emergence of the field of "osteoimmunology" has provided a conceptual framework to explain how the immune and skeletal systems interact. Furthermore, it is becoming clear that inflammatory states leading to perturbations in the immuno-skeletal interface, a convergence of common cells and cytokine mediators that regulate both immune and skeletal systems, conspire to imbalance bone turnover and induce osteoporosis. In this review we examine the role of inflammation in the bone loss associated with diverse inflammatory conditions and new concepts into how the underlying mechanisms by which inflammation and immune dysregulation impact bone turnover may be pertinent to the mechanisms involved in HIV/ART-induced bone loss.

Accelerated aging and human immunodeficiency virus infection: emerging challenges of growing older in the era of successful antiretroviral therapy

HIV-infected patients are living longer as a result of potent antiretroviral therapy. Immuno-inflammatory phenomena implicated in the normal aging process, including immune senescence, depreciation of the adaptive immune system, and heightened systemic inflammation are also pathophysiologic sequelae of HIV infection, suggesting HIV infection can potentiate the biological mechanisms of aging. Aging HIV-infected patients manifest many comorbidities at earlier ages, and sometimes with more aggressive phenotypes compared to seronegative counterparts. In this review, we describe relevant biologic changes shared by normal aging and HIV infection and explore the growing spectrum of clinical manifestations associated with the accelerated aging phenotype in HIV-infected individuals.

Osteopenia and osteoporosis in people living with HIV: multiprofessional approach

Increasing bone mineralization abnormalities observed among people living with HIV (PLWHIV) result from various factors relating to the host, the virus, and the antiretrovirals used. Today, HIV infection is considered to be a risk factor for bone mineralization disorders. The test most recommended for diagnosing osteoporosis is measurement of bone mineral density by means of dual energy X-ray absorptiometry at two sites. Osteoporosis treatment has the aims of bone mass improvement and fracture control. A combination of calcium and vitamin D supplementation may reduce the risk of fractures. Antiresorptive drugs act by blocking osteoclastic activity and reducing bone remodeling. On the other hand, bone-forming drugs stimulate osteoblastogenesis, thereby stimulating the formation of bone matrix. Mixed-action medications are those that are capable of both stimulating bone formation and inhibiting reabsorption. Antiresorptive drugs form the group of medications with the greatest quantity of scientific evidence confirming their efficacy in osteoporosis treatment. Physical activity is a health promotion strategy for the general population, but only preliminary data on its real value and benefit among PLWHIV are available, especially in relation to osteoporosis.

Bone mineral density in HIV-negative men participating in a tenofovir pre-exposure prophylaxis randomized clinical trial in San Francisco

BACKGROUND

Pre-exposure prophylaxis (PrEP) trials are evaluating regimens containing tenofovir-disoproxil fumarate (TDF) for HIV prevention. We determined the baseline prevalence of low bone mineral density (BMD) and the effect of TDF on BMD in men who have sex with men (MSM) in a PrEP trial in San Francisco.

METHODS/FINDINGS

We evaluated 1) the prevalence of low BMD using Dual Energy X-ray Absorptiometry (DEXA) in a baseline cohort of 210 HIV-uninfected MSM who screened for a randomized clinical trial of daily TDF vs. placebo, and 2) the effects of TDF on BMD in a longitudinal cohort of 184 enrolled men. Half began study drug after a 9-month delay to evaluate changes in risk behavior associated with pill-use. At baseline, 20 participants (10%) had low BMD (Z score≤-2.0 at the L2-L4 spine, total hip, or femoral neck). Low BMD was associated with amphetamine (OR = 5.86, 95% CI 1.70-20.20) and inhalant (OR = 4.57, 95% CI 1.32-15.81) use; men taking multivitamins, calcium, or vitamin D were less likely to have low BMD at baseline (OR = 0.26, 95% CI 0.10-0.71). In the longitudinal analysis, there was a 1.1% net decrease in mean BMD in the TDF vs. the pre-treatment/placebo group at the femoral neck (95% CI 0.4-1.9%), 0.8% net decline at the total hip (95% CI 0.3-1.3%), and 0.7% at the L2-L4 spine (95% CI -0.1-1.5%). At 24 months, 13% vs. 6% of participants experienced >5% BMD loss at the femoral neck in the TDF vs. placebo groups (p = 0.13).

CONCLUSIONS

Ten percent of HIV-negative MSM had low BMD at baseline. TDF use resulted in a small but statistically significant decline in BMD at the total hip and femoral neck. Larger studies with longer follow-up are needed to determine the trajectory of BMD changes and any association with clinical fractures.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00131677.

HIV and bone metabolism

The skeleton is an organ whose integrity is maintained by constant lifelong renewal involving coordinated removal of worn bone by osteoclasts and resynthesis of new bone by osteoblasts. In young adult humans and animals this process is homeostatic with no net gain or loss of bone mass. With natural aging and exacerbated by numerous pathological conditions, bone removal exceeds bone formation, disrupting homeostasis and resulting in bone loss. Over time, skeletal decline reaches clinical significance with development of osteopenia and eventually osteoporosis, conditions that dramatically increase bone fragility and the risk of fracture. Bone fractures can be devastating with significant morbidity and mortality. Over the last decade, it has become clear that skeletal renewal is strongly influenced by the immune system, a consequence of deep integration and centralization of common cell types and cytokine mediators, which we have termed the "immuno-skeletal interface." Consequently, dysregulated skeletal renewal and bone loss is a common feature of inflammatory conditions associated with immune activation. Interestingly, bone loss is also associated with conditions of immunodeficiency, including infection by the human immunodeficiency virus (HIV) that leads to acquired immunodeficiency syndrome (AIDS). Disruptions to the immuno-skeletal interface drive skeletal deterioration contributing to a high rate of bone fracture in HIV infection. This review examines current knowledge concerning the prevalence and etiology of skeletal complications in HIV infection, the effect of antiretroviral therapies (ART) on the skeleton, and how disruption of the immuno-skeletal interface may underlie bone loss in HIV infection and ART.