Pathogenesis of osteopenia/osteoporosis induced by highly active anti-retroviral therapy for AIDS

Drug-induced osteoporosis and mechanisms of bone tissue regeneration through trace elements

Osteoporosis is associated with an imbalance in bone formation, with certain drugs used in disease treatment being implicated in its development. Supplementation with trace elements may contribute to bone regeneration, offering an alternative approach by enhancing bone mineral density (BMD) and thereby thwarting the onset of osteoporosis. This review aims to assess the mechanisms through which trace elements such as copper (Cu), iron (Fe), selenium (Se), manganese (Mn), and zinc (Zn) are linked to increased bone mass, thus mitigating the effects of pharmaceuticals. Our findings underscore that the use of drugs such as aromatase inhibitors (AIs), proton pump inhibitors (PPIs), antiretrovirals, glucocorticoids, opioids, or anticonvulsants can result in decreased BMD, a primary contributor to osteoporosis. Research indicates that essential elements like Cu, Fe, Se, Mn, and Zn, through various mechanisms, can bolster BMD and forestall the onset of the disease, owing to their protective effects. Consequently, our study recommends a minimum daily intake of these essential minerals for patients undergoing treatment with the aforementioned drugs, as the diverse mechanisms governing the effects of trace elements Cu, Fe, Mn, Se, and Zn facilitate bone remodeling.

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.

Unveiling the basis of antiretroviral therapy-induced osteopenia: the effects of Dolutegravir, Darunavir and Atazanavir on osteogenesis

OBJECTIVES

Osteopenia is frequent in HIV-infected patients treated with antiretroviral therapy (ART) and has been linked to increased osteoclastogenesis. Little is known about the effects of ART on osteogenesis.

DESIGN

We investigated the effect on human mesenchymal stem cells (hMSC) and osteoblasts of Darunavir and Dolutegravir, the most highly used as anchor drugs within a three-drug regimen, and Atazanavir, which was widely utilized in the past.

RESULTS

We found that Atazanavir and Dolutegravir delay the osteogenic differentiation of hMSC, impair the activity of osteoblasts and inhibit their conversion into osteocytes, whereas Darunavir exerts no effect.

CONCLUSION

Atazanavir and Dolutegravir impair osteogenesis. It is essential to diagnose impaired osteogenesis early and to devise effective therapeutic interventions to preserve bone health in ART-treated HIV patients, putting it in the context of a correct antiretroviral combination.

Retrospective study of the success of dental implants placed in HIV-positive patients

BACKGROUND

Data related to HIV-positive patients with dental implants is short-termed and limited. Recent data showed that both HIV and antiretroviral therapy (ART) could lead to low bone mineral density (BMD). The aim of this study was to determine the success rate of dental implants in HIV-positive patients.

MATERIALS AND METHODS

Dental files of 67 HIV-positive patients were selected and reviewed retrospectively, and 18 subjects agreed to return for examination. All implants were evaluated using periapical radiographs that were calibrated to measure bone loss. Crestal bone loss, mobility, and lack of infection were the parameters used to determine implant success.

RESULTS

All dental implants evaluated lacked mobility and infection. Bone loss averaged 0.5 mm in 3.6 years. Subjects were consistent with maintenance and oral hygiene.

CONCLUSIONS

Within the limitations of this study, the results suggest that the placement of dental implants on HIV-positive patients is safe and effective.

Antiretroviral Therapy and Bone Health

Objective: To determine the incidence of osteopenia and osteoporosis in Bulgarian human immunodeficiency virus (HIV)-infected patients.

Methods: Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry in 41 Bulgarian HIV-infected patients.

Results: Overall, 27% of patients had reduced BMD (7% osteoporosis and 20% osteopenia). There was a significant correlation between low BMD and increasing age and between low BMD and duration of antiretroviral therapy (ART) but no correlation with gender, therapy regimen or serum calcium or phosphate levels. Seventy-one percent had elevated serum cystatin C levels but there was no correlation between BMD and cystatin C levels. Serum calcium, phosphate, cystatin C and creatinine levels and the T- and Z-scores were tested for dependence on duration of therapy. Dependence was found for T- and Z-scores, (p = 0.048 and p = 0.038) but not for calcium, phosphate, cystatin C or creatinine levels. These variables were subsequently tested by means of cross-tabulation tables for correlations between pairs of parameters; no significant correlation was found between any pairs (R > 0.5 for all comparisons).

Conclusions: Significant correlations were observed between low BMD and increasing age and longer duration of ART but no relationship was observed with gender or therapy regimen.

Clinical outcome of kidney transplantation in HIV-infected recipients: a retrospective study

Kidney transplantation is a safe and effective option for HIV-positive (HIV⁺) patients. We conducted a retrospective study on HIV⁺ kidney transplant recipients who underwent transplantation from March 2008 to September 2016. Inclusion criteria for transplantation were CD4+ T-cell count ≥200 per mm³ and undetectable HIV load. The current study reports the outcome of 19 HIV⁺ recipients, mostly of Caucasian origin (79%) with a median age of 50 years (interquartile range [IQR], 42-52), who were followed up for a median period of 2.4 years (IQR, 1.2-4.6) after transplantation. Compared with HIV-negative (HIV^-) controls, HIV⁺ recipients had similar one- and three-year graft and patient survival, but significantly lower five-year patient survival (P = 0.03). The differences in graft outcome became less evident with the analysis of death-censored graft survival rates. Cumulative incidence of allograft rejection at one year was 32.9%. Rates of infections were not particularly elevated and HIV replication remained well controlled in all but one patient. A high prevalence of metabolic and endocrine complications (68%) was reported after transplantation. Further studies are needed to evaluate long-term outcomes of HIV⁺ recipients who underwent kidney transplantation.

Effect of Antiretroviral Therapy on Bone and Renal Health in Young Adults Infected With HIV in Early Life

Context

HIV antiretroviral (ARV) therapy is associated with renal and bone toxicity, but little is known about the potential cumulative effects in adults exposed to ARVs from birth.

Objective

To prospectively evaluate renal and bone health in young adults with lifelong HIV and extensive ARV exposure.

Design

Cross-sectional comparison of bone mineral density (BMD) by dual-energy X-ray absorptiometry, bone turnover, and renal function in young adults infected with HIV in early life (n = 65) to matched healthy controls (n = 23) and longitudinal evaluation (mean follow-up = 4.4 years) within a subset of the HIV cohort (n = 33).

Setting

Government outpatient research clinic.

Results

Albumin/creatinine ratio, protein/creatinine ratio, anion gap, N-terminal telopeptides, and osteocalcin were significantly increased in persons with HIV compared with controls, whereas whole-body BMD and BMD z scores were lower. Within the HIV group, duration of tenofovir disoproxil fumarate (TDF) correlated with higher anion gap but did not correlate with bone parameters. Longer duration of didanosine and stavudine use correlated with lower BMD and BMD z scores. Longitudinal analyses revealed that BMD and bone metabolism significantly improved over time. No subject had an estimated glomerular filtration rate (eGFR) <60, but decline in eGFR correlated with increasing years of TDF exposure.

Conclusions

Subclinical markers of renal dysfunction were increased in HIV-infected young adults and associated with TDF exposure, whereas lower bone density was associated with didanosine and stavudine exposure. The tendency for improvement in markers of bone health over time and the availability of less toxic ARV alternatives may herald improvements in renal and bone health for perinatally infected patients in adulthood.

Management of endocrine disease: Secondary osteoporosis: pathophysiology and management

Osteoporosis is a skeletal disorder characterized by decreased mass and compromised bone strength predisposing to an increased risk of fractures. Although idiopathic osteoporosis is the most common form of osteoporosis, secondary factors may contribute to the bone loss and increased fracture risk in patients presenting with fragility fractures or osteoporosis. Several medical conditions and medications significantly increase the risk for bone loss and skeletal fragility. This review focuses on some of the common causes of osteoporosis, addressing the underlying mechanisms, diagnostic approach and treatment of low bone mass in the presence of these conditions.

Changes in bone mineral density after 96 weeks of treatment with atazanavir/ritonavir or lopinavir/ritonavir plus tenofovir DF/emtricitabine in treatment-naive patients with HIV-1 infection: the CASTLE body composition substudy

: Antiretroviral therapy initiation is associated with declines in bone mineral density (BMD), which seem greatest with tenofovir disoproxil fumarate (DF)-containing regimens. Data comparing protease inhibitors are limited. This CASTLE substudy compared paired baseline with week 96 BMD in patients initiating tenofovir DF/emtricitabine plus atazanavir/ritonavir (n = 106) vs lopinavir/ritonavir (n = 70). In both groups, week 96 BMD declined significantly in arm, leg, trunk, and total body regions. Atazanavir/ritonavir was associated with smaller 96-week trunk and total body BMD declines compared with lopinavir/ritonavir [multivariate-adjusted least squares mean difference +2.00% (95% confidence interval: 0.52 to 3.45; P = 0.008) and +1.24% (95% confidence interval: 0.13 to 2.35; P = 0.029), respectively]. In addition, low baseline CD4 cell count (<50 cells per microliter) and increasing age were associated with larger declines in BMD.

HIV infection and osteoporosis

In the past two decades, the life expectancy of people living with HIV infection has increased significantly, and osteoporosis has emerged as a significant comorbidity. In addition to traditional risk factors for fracture, specific factors related to HIV infection are also likely to contribute, including antiretroviral therapy. The heterogeneity of the HIV-infected population in terms of age and ethnicity presents many challenges to the prevention and management of bone disease, and further studies are required to establish optimal approaches to risk assessment and treatment.

Complications related to fracture treatment in HIV patients: a case report

We present the case report of a 40-year-old woman who was HIV-positive in Highly Active Anti-Retroviral Therapy (HAART) and affected by femural pertrochanteric fracture, which was treated by endomedullary nailing. Two years after the surgical operation, the woman developed an aseptic symptomatic osteolysis around the implant. Hardware removal was resolutive. Aseptic and septic hardware mobilization, hardware removal, and implant decision in HIV patients with pertrochanteric fractures is discussed. The authors suggest close follow-up and prompt hardware removal, as soon as X-rays demonstrate healing signs, in HIV patients with fracture fixation, if general condition allows.

Early loss of bone mineral density is correlated with a gain of fat mass in patients starting a protease inhibitor containing regimen: the prospective Lipotrip study

BACKGROUND

HIV-infected patients starting antiretroviral treatment (ART) experience deep and early disorders in fat and bone metabolism, leading to concomitant changes in fat mass and bone mineral density.

METHODS

We conducted a prospective study in treatment-naive HIV-infected patients randomized to receive two nucleoside reverse transcriptase inhibitors in combination with either a protease inhibitor (PI) or a non-nucleosidic reverse transcriptase inhibitor (NNRTI), to evaluate early changes in body composition, bone mineral density and metabolic markers as differentially induced by antiretroviral therapies. We measured changes in markers of carbohydrate, of fat and bone metabolism, and, using dual-emission X-ray absorptiometry (DXA), body composition and bone mineral density (BMD). Complete data on changes between baseline and after 21 months treatment were available for 35 patients (16 in the PI group and 19 in the NNRTI group).

RESULTS

A significant gain in BMI and in total and lower limb fat mass was recorded only in patients receiving PI. A loss of lumbar BMD was observed in both groups, being higher with PI. Plasma markers of bone metabolism (alkaline phosphatase, osteocalcin, collagen crosslaps) and levels of parathormone and of 1,25diOH-vitamin D3 significantly increased in both groups, concomitant with a decline in 25OH-vitamin D3. Lipids and glucose levels increased in both groups but rise in triglyceride was more pronounced with PI. A correlation between loss of BMD and gain of fat mass is observed in patients starting PI.

CONCLUSIONS

We evidenced an early effect of ART on lipid and bone metabolisms. PI lead to a significant gain in fat mass correlated with a sharp drop in BMD but active bone remodelling is evident with all antiretroviral treatments, associated with low vitamin D levels and hyperparathyroidism. In parallel, signs of metabolic restoration are evident. However, early increases in lean and fat mass, triglycerides, waist circumference and leptin are much more pronounced with PI.

HIV and Bone Disease: A Perspective of the Role of microRNAs in Bone Biology upon HIV Infection

Increased life expectancy and the need for long-term antiretroviral therapy have brought new challenges to the clinical management of HIV-infected individuals. The prevalence of osteoporosis and fractures is increased in HIV-infected patients; thus optimal strategies for risk management and treatment in this group of patients need to be defined. Prevention of bone loss is an important component of HIV care as the HIV population grows older. Understanding the mechanisms by which HIV infection affects bone biology leading to osteoporosis is crucial to delineate potential adjuvant treatments. This review focuses on HIV-induced osteoporosis within the context of microRNAs (miRNAs) by reviewing first basic concepts of bone biology as well as current knowledge of the role of miRNAs in bone development. Evidence that HIV-associated osteoporosis is in part independent of therapies employed to treat HIV (HAART) is supported by cross-sectional and longitudinal studies and is the focus of this review.

Osteoporosis and Vitamin D Deficiency in HIV-Positive Patients

Objective:

To review the epidemiology and pathophysiology of osteoporosis in patients with HIV infection and discuss vitamin D deficiency and the treatment of HIV-positive patients with osteoporosis.

Data Sources:

A search of PubMed (1980–June 2011) was conducted using the terms osteoporosis, HIV, vitamin D deficiency, and treatment.

Study Selection and Data Extraction:

Epidemiologic studies, clinical trials, and meta-analyses published in English were included. A manual review of the bibliographies of available literature was conducted and relevant articles were reviewed for inclusion.

Data Synthesis:

Patients with HIV infection are living longer with the use of potent antiretroviral therapy (ART) and are at increased risk for osteoporosis. Several studies have shown that HIV infection can affect bone health and increase the risk for osteoporosis. In addition, ART, and tenofovir in particular, may affect bone turnover. Studies and meta-analyses have shown an increased prevalence of osteopenia and osteoporosis in HIV-positive patients compared to noninfected controls. Recent reports also show increased prevalence of fractures and low vitamin D concentrations in HIV-positive patients. Osteoporosis treatments used in patients with HIV infection are similar to treatments for noninfected patients. HIV-positive patients should be monitored and treated to prevent the progression and complications of osteoporosis.

Conclusions:

HIV-positive patients are at increased risk for osteoporosis and vitamin D deficiency due to disease and treatment influences on bone health. These patients should be identified and treated to prevent the morbidity and mortality associated with osteoporosis.

Bone mineral density in HIV-infected women taking antiretroviral therapy: a systematic review

There is a high prevalence of osteoporosis in HIV-infected patients. Initially described in HIV-positive men, studies have also demonstrated a high prevalence of osteoporosis in HIV-infected women. It would appear that antiretroviral therapy (ART) plays an important role in the pathogenesis of osteoporosis in HIV-infected patients, although little is known about its importance in relation to osteoporosis and fractures in HIV-positive women. The aim of this systematic review was to evaluate the frequency of bone loss, bone mineral density (BMD) and fractures in HIV-positive women taking ART or protease inhibitors (PI). After screening 597 citations from the databases of PubMed, EMBASE and Lilacs, five studies were selected for the review. A difference was demonstrated of over 3% in the BMD at the femoral neck of HIV-positive women taking PI/ART. No difference was registered in the BMD at the lumbar spine between users and non-users of PI/ART. The lack of studies has made it impossible to reach any conclusion regarding the occurrence of fractures.

Prospective one-year bone loss in treatment-naïve HIV+ men and women on single or multiple drug HIV therapies

Antiretroviral therapy has decreased the rate of HIV-related mortality and extended the life span of HIV patients. Current guidelines recommend the use of a 3-drug regimen, such as two nucleoside reverse transcriptase inhibitors and a protease inhibitor, boosted by ritonavir. Osteoporosis can be associated with the HIV disease itself or with antiretroviral therapy. Many trials have been conducted employing a single drug regimen to simplify antiretroviral therapy but few studies assessed the effect of the single drug regimen on bone mineral density (BMD). The objectives of the study were to assess and compare the relative (%) changes in lumbar spine and hip BMD over 48 weeks in HIV patients treated with mono or triple antiretroviral regimens The study was conducted using data from a randomized trial (MONARK) conducted in 136 antiretroviral-naïve HIV patients (89 men and 47 women) comparing the antiviral efficacy of a single-drug protease inhibitor regimen of lopinavir/ritonavir (LPV/r) versus LPV/r in combination with zidovudine (ZDV) and lamivudine (3TC). Lumbar spine and total hip BMD were assessed in 100 patients by dual-energy X-ray absorptiometry at baseline and 48 weeks. 48 week-BMD data were available for 43 patients (mean age 37years) with a mean baseline lumbar spine Z-score of -0.1 in the LPV/r monotherapy group and for 25 patients (mean age 35.8years) with a mean baseline lumbar spine Z-score of -0.2 in the LPV/r+ZDV+3TC group. After 48weeks, lumbar spine BMD significantly decreased by 4.4% (-5.1% to -2.1%, P≤0.001) in the LPV/r group and by 4.0% (-5.0% to -1.7%, P≤0.0001) in the LPV/r+ZDV+3TC group. There was no significant difference in BMD changes between the two groups. These results suggest that bone loss is observed 48 weeks after the initiation of antiretroviral therapy, whether the patients receive a single- or triple-drug antiretroviral regimen.

Secondary complications and co-infections in the HIV-infected adolescent in the antiretroviral era

PURPOSE OF REVIEW

The number of HIV-infected adolescents is increasing dramatically. With combination antiretroviral therapy, they are expected to live well into adulthood. However, complications are emerging at a higher rate in the HIV-infected population compared to the general population. HIV-infected adolescents are also at a high risk of sexually transmitted co-infections. This article reviews the main secondary complications and co-infections in the HIV-infected adolescent.

RECENT FINDINGS

HIV-infected adolescents are at a high risk of sexually transmitted infections. A careful, age-appropriate and developmentally appropriate inquiry into the individual's sexual behavior to assess risk is paramount, in addition to regular screening at medical visits. Treating co-infections is not only important for HIV-infected individuals, but also limits HIV transmission to others. In addition, monitoring and addressing modifiable secondary risk factors for complications such as renal disease, osteopenia or osteoporosis, and cardiovascular disease are critical, well before the onset of clinically apparent disease. Using antiretroviral therapy to suppress viral replication and inflammation appears to be a promising strategy for decreasing secondary complication risk, and likely overshadows the toxicities associated with the long-term use of certain antiretrovirals.

SUMMARY

Assessing and addressing the risk of secondary complications and co-infections in the HIV-infected adolescent is crucial for optimal length and quality of life.

Aging, human immunodeficiency virus, and bone health

Highly active antiretroviral therapy (HAART) has had a profound impact on improving the long-term prognosis for individuals infected with human immunodeficiency virus (HIV). HAART has been available for close to two decades, and now a significant number of patients with access to HAART are over the age of 50 years. Many clinical studies have indicated that HIV infection, as well as components of HAART, can increase the risk in these individuals to a variety of noninfectious complications, including a risk to bone health. There is a significant need for detailed mechanistic analysis of the aging, HIV-infected population regarding the risk of HIV infection and therapy in order to maintain bone health. Insights from basic mechanistic studies will help to shed light on the role of HIV infection and the components of HAART that impact bone health, and will help in identifying preventative countermeasures, particularly for individuals 50 years of age and older.

Enhanced mitochondrial biogenesis contributes to Wnt induced osteoblastic differentiation of C3H10T1/2 cells

Mitochondria play a key role in cell physiology including cell differentiation and proliferation. We investigated the changes of mitochondrial biogenesis during Wnt-induced osteoblastic differentiation of murine mesenchymal C3H10T1/2 cells. Scanning electron microscopy demonstrated that activation of Wnt signaling by Wnt-3A conditioned medicum (CM) resulted in significant increase in the number of mitochondria in C3H10T1/2 cells. In addition, the induction of alkaline phosphatase (ALP) activities by Wnt-3A CM was accompanied by significant increase in mitochondrial mass (p<0.05), mitochondrial membrane potential (p<0.05), intracellular reactive oxygen species production (p<0.05), resting oxygen consumption rate (p<0.05), cellular ATP content (p< or =0.05) and mtDNA copy number (p<0.05) compared to the cells with control CM (L292-CM) treatment. Moreover, co-treatment with Dkk-1 or WIF-1, both of which are Wnt inhibitors, abrogated the Wnt-3A-induced ALP activities as well as mitochondrial biogenesis markers. Upregulation of mitochondrial biogenesis by overexpression of mitochondrial transcription factor A (Tfam) significantly enhanced Wnt-induced osteogenesis as measured by ALP activities. In contrast, inhibition of mitochondrial biogenesis by treatment with Zidovudine (AZT) resulted in significant inhibition of ALP activities. Finally, ALP activities in human osteosarcoma cell line devoid of mitochondrial DNA (rho(0) cells) was significantly suppressed both in basal and Wnt-3A stimulated state compared to those from mitochondria-intact cells (rho+ cells). As a mechanism for Wnt-mediated mitochondrial biogenesis, we found that Wnt increased the expression of PGC-1alpha, a critical molecules in mitochondrial biogenesis, through Erk and p38 MAPK pathway independent of beta-catenin signaling. We also found that increased mitochondrial biogenesis is in turn positively regulating TOPflash reporter activity as well as beta-catenin levels. To summarize, mitochodrial biogenesis is upregulated by Wnt signaling and this upregulation contributes to the osteoblastic differentiation of mouse mesenchymal C3H10T1/2 cells.

[Adverse reactions of atazanavir, fosamprenavir and tipranavir in "real life"]

OBJECTIVE

To precise adverse effects of atazanavir, fosamprenavir and tipranavir "in real life".

METHOD

Descriptive study of 3 protease inhibitor adverse effects stored in the French Bank of Pharmacovigilance.

RESULTS

Nineteen adverse effects having at least possible links with antiretroviral drugs studied were reported. It was essentially hepatobiliary (atazanavir: 29/59, tipranavir: 4/6) and skin (fosamprenavir: 10/20) adverse reactions. These reactions, relatively "serious" (35.1%) led to the interruption of the person (or persons) medication (s) suspected (s) in 69 folds (82.1%) and evolved to healing without sequelae in 68 folds (81%).

CONCLUSION

The drug side effects were for the most expected. However, their frequency and their seriously underline the interest of a post-AMM monitoring to reassess the drugs risk-benefit report.

Zidovudine and Lamivudine for HIV Infection

Zidovudine and lamivudine (ZDV and 3TC) are long-standing nucleoside analog-reverse transcriptase inhibitors (NRTIs) with extensive clinical experience in a wide spectrum of patients from in utero through childhood and adult ages. The safety profiles of both drugs are well-known and side effects for ZDV most commonly include nausea/vomiting, fatigue, anemia/neutopenia, and lipoatrophy; while 3TC is well-tolerated. ZDV-3TC is currently a viable alternative NRTI backbone for initial three-drug therapy of HIV infection when tenofovir disoproxil fumarate-emtricitabine (TDF-FTC) cannot be used because of a relative or absolute contraindication. ZDV-3TC continue to be viable alternatives for children, pregnant women and in resource limited settings where other recommended options are not readily available. ZDV-3TC penetrate the Central Nervous System (CNS) well, which makes ZDV-3TC attractive for use in patients with HIV-associated neurological deficits. Additional benefits of these drugs may include the use of ZDV in combination with certain NRTIs to exert selective pressure to prevent particular drug resistance mutations from developing, and giving a short course of ZDV-3TC to prevent resistance after prophylactic single dose nevirapine.

First line zidovudine/lamivudine/lopinavir/ritonavir leads to greater bone loss compared to nevirapine/lopinavir/ritonavir

OBJECTIVE

We studied changes in bone mineral density (BMD) and bone turnover after initiation of combination antiretroviral therapy (cART) and the contribution of zidovudine/lamivudine (ZDV/3TC) in particular.

DESIGN

Randomized clinical trial comparing lopinavir/ritonavir(LPV/r) + ZDV/3TC with LPV/r + nevirapine (NVP) in 50 cART-naive men.

METHODS

Dual energy X-ray absorptiometry (DXA) and quantitative computed tomography scans (QCT) were performed at baseline and 3, 12, and 24 months after cART initiation. Serum 25-hydroxy-vitamin D3, parathyroid hormone (PTH), osteocalcin, and urine deoxypyridinoline (DPD)/creatinine ratio were measured.

RESULTS

BMD decreased rapidly in both femoral neck and lumbar spine after cART initiation. BMD loss during 24 months measured by DXA, but not by QCT, was greater in the ZDV/3TC/LPV/r group compared to the NVP/LPV/r group [femoral neck: -6.3% +/- 1.0% (P < 0.0001) compared to -2.3% +/- 0.9% (P = 0.01), between-group P = 0.0006); lumbar spine: -5.1% +/- 0.8% (P < 0.0001) compared to -2.6% +/- 0.7% (P = 0.0006), between-group P = 0.07]. Osteocalcin [+1.60 +/- 0.32 (P < 0.0001) and +1.81 +/- 0.29 (P < 0.0001) nmol/l] and the urine DPD/creatinine ratio [+1.35 +/- 0.44 (P = 0.0029) and +1.19 +/- 0.38 nmol/mmol (P = 0.0024)] increased in both groups over 24 months, with no significant difference between groups. PTH increased to a greater degree in the NVP/LPV/r group [+2.0 +/- 0.31 pmol/l (P < 0.0001)] compared to [+0.81 +/- 0.33 pmol/l (P = 0.021) in the ZDV/3TC/LPV/r group].

CONCLUSION

BMD in both femoral neck and lumbar spine decreased rapidly after initiation of cART, in parallel to an increase in bone turnover. The greater bone loss in the ZDV/3TC/LPV/r group compared to the NVP/LPV/r group suggests that ZDV/3TC contributes to this process. The PTH increase does not explain this greater bone loss.

Is PPARγ a prospective player in HIV-1-associated bone disease?

Currently infection with the human immunodeficiency virus-1 (HIV-1) is in most instances a chronic disease that can be controlled by effective antiretroviral therapy (ART). However, chronic use of ART has been associated with a number of toxicities; including significant reductions in bone mineral density (BMD) and disorders of the fat metabolism. The peroxisome proliferator-activated receptor γ (PPARγ) transcription factor is vital for the development and maintenance of mature and developing adipocytes. Alterations in PPARγ expression have been implicated as a factor in the mechanism of HIV-1-associated lipodystrophy. Both reduced BMD and lipodystrophy have been well described as complications of HIV-1 infection and treatment, and a question remains as to their interdependence. Interestingly, both adipocytes and osteoblasts are derived from a common precursor cell type; the mesenchymal stem cell. The possibility that dysregulation of PPARγ (and the subsequent effect on both osteoblastogenesis and adipogenesis) is a contributory factor in the lipid- and bone-abnormalities observed in HIV-1 infection and treatment has also been investigated. This review deals with the hypothesis that dysregulation of PPARγ may underpin the bone abnormalities associated with HIV-1 infection, and treats the current knowledge and prospective developments, in our understanding of PPARγ involvement in HIV-1-associated bone disease.

Bone health in HIV infection

INTRODUCTION

Osteoporosis is among the chronic problems emerging as the human immunodeficiency virus (HIV)-positive population ages.

SOURCES OF DATA

We reviewed the English language bibliography using Pubmed 2.0, Web of Science and Embase for relevant abstracts and articles.

AREAS OF AGREEMENT

The prevalence of low bone mineral density (BMD) and fracture is increased in the HIV-positive population.

AREAS OF CONTROVERSY

The pathogenesis is multifactorial; there is some evidence that HIV infection is an independent risk factor and that highly active antiretroviral therapy has adverse skeletal effects.

GROWING POINTS

Physicians should routinely review the bone health of all HIV patients.

AREAS TIMELY FOR DEVELOPING RESEARCH

More studies of the mechanisms of bone loss, the skeletal effects of antiretroviral therapy and the therapeutic outcome of bone-protective therapy in HIV-positive individuals are needed.

Fracture healing in HIV-positive populations

Highly active anti-retroviral therapy has transformed HIV into a chronic disease with a long-term asymptomatic phase. As a result, emphasis is shifting to other effects of the virus, aside from immunosuppression and mortality. We have reviewed the current evidence for an association between HIV infection and poor fracture healing.

The increased prevalence of osteoporosis and fragility fractures in HIV patients is well recognised. The suggestion that this may be purely as a result of highly active anti-retroviral therapy has been largely rejected. Apart from directly impeding cellular function in bone remodelling, HIV infection is known to cause derangement in the levels of those cytokines involved in fracture healing (particularly tumour necrosis factor-α) and appears to impair the blood supply of bone.

Many other factors complicate this issue, including a reduced body mass index, suboptimal nutrition, the effects of anti-retroviral drugs and the avoidance of operative intervention because of high rates of wound infection. However, there are sound molecular and biochemical hypotheses for a direct relationship between HIV infection and impaired fracture healing, and the rewards for further knowledge in this area are extensive in terms of optimised fracture management, reduced patient morbidity and educated resource allocation. Further investigation in this area is overdue.

Incidence and prevalence of medication-induced osteoporosis: evidence-based review

(1) While a number of medications have been shown to induce bone loss, the actual incidence and prevalence of medication-induced osteoporosis has not been well quantified. (2) Oral corticosteroids contribute to an increased prevalence of osteoporosis and an increased incidence of fracture in a number of different populations. The increased incidence of fracture in patients receiving inhaled corticosteroids for respiratory disease may be attributed to disease pathogenesis rather than the effects of medication. (3) Other therapies that increase the incidence and/or prevalence of medication-induced osteoporosis and fracture include androgen-deprivation therapy, aromatase inhibitors, protease inhibitors, selective serotonin reuptake inhibitors and prolactin-raising antiepileptic agents. (4) It is difficult to make definitive conclusions on the actual increase in the prevalence and/or incidence of osteoporosis in patients receiving certain medications, as values are often reported differently and studies are mainly retrospective and are therefore open to inherent selection biases and other confounders. Furthermore, there is little available information as to whether specific medications within a class are associated with a higher rate of bone disease than others.

Risk factors for decreased bone density and effects of HIV on bone in the elderly

Most studies of bone density in HIV-infected individuals focus on young men. This study compares differences in bone density in elderly HIV positive men and women to HIV negative controls. Bone density was lower in the lumbar spine and hip in the HIV-infected group. Antiretrovirals may be associated with decreased bone mineralization.

INTRODUCTION

Individuals with human immunodeficiency virus (HIV) may be at increased risk for osteoporosis. Prolonged exposures to HIV and/or antiretroviral therapy are possible causes for this association. This study compares differences in bone mineral density (BMD) in elderly HIV positive men and women to HIV negative controls.

METHODS

A cross-sectional study was conducted among 57 HIV-infected and 47 HIV negative subjects over age 55. BMD at the lumbar spine and total hip and markers of bone turnover were compared.

RESULTS

BMD was borderline lower in the lumbar spine and significantly lower in the hip in the HIV-infected group. Controlling for age, sex, race and body mass index, differences between the groups were significant at both sites. There was no difference in markers of bone turnover between the groups. Tenofovir use was significantly associated with decreased BMD at the spine while protease inhibitor use was significantly associated with decreased BMD at the hip.

CONCLUSION

Elderly men and women with HIV have lower bone mass than HIV negative controls. Decreased body mass index was the most important risk factor associated with decreased BMD. Bone demineralization was observed among HIV-infected subjects receiving either tenofovir or a protease inhibitor.

Effect of reducing the dose of stavudine on body composition, bone density, and markers of mitochondrial toxicity in HIV-infected subjects: a randomized, controlled study

BACKGROUND

Stavudine is widely used in developing countries. Lipoatrophy and mitochondrial toxicity have been linked to stavudine use, but it is unclear whether switching to a lower dose can reduce these toxicities while maintaining human immunodeficiency virus (HIV) suppression.

METHODS

HIV-infected subjects receiving standard-dose stavudine with undetectable HIV type 1 RNA for > or =6 months were randomized (ratio, 3:2) to receive one-half of the stavudine dose (switch arm) or to maintain the dose (continuation arm) while continuing to receive all other prescribed antiretrovirals. The following measurements were obtained at baseline and week 48: fasting lactate, pyruvate, and lipid levels; results of whole-body dual-energy x-ray absorptiometry; and mitochondrial DNA (mtDNA) measurements in fat and peripheral blood mononuclear cells. Change from baseline to week 48 was compared within and between groups.

RESULTS

Twenty-four patients (79% of whom were men and 79% of whom were African American; median age, 45 years) were enrolled in the study, 15 were enrolled in the switch arm, and 9 were enrolled in the continuation arm. The median duration of stavudine treatment was 55 months (range, 21-126 months). The median CD4 cell count was 558 cells/mm(3) (range, 207-1698 cells/mm(3)). At baseline, the study arms had similar demographic characteristics and laboratory indices, except for body mass index, total lean body mass, and triglyceride levels (all of which were higher in the switch arm). Three patients (2 in the switch arm) discontinued the study because of study-unrelated reasons. CD4 cell counts remained unchanged. At 48 weeks, 6 patients (4 [27%] in the switch arm and 2 [22%] in the continuation arm) had detectable HIV RNA levels (median, 972 copies/mL; range, 60-49,400 copies/mL). All patients with detectable HIV RNA levels reported significant lapses in treatment adherence; none exhibited mutations in HIV genotype. After the treatment switch, significant changes from study entry to week 48 were noted only for lactate level (median change, -0.27 mmol/L; range, -1.2 to 0.25 mmol/L; P = .02) and fat mtDNA (median change, 40 copies/cell; range, -49 to 261 copies/cell; P = .02). In the continuation arm, a significant loss of bone mineral density was seen at week 48 (median change, -1.7%; range, -6.3% to 0.8%; P = .02). The only significant between-group difference was the change in bone mineral density from baseline (P = .003).

CONCLUSIONS

Reducing stavudine dose by one-half increased fat mtDNA and decreased lactate levels, suggesting improvement in mitochondrial indices while preserving HIV suppression in subjects who maintained adherence. A significant loss of bone mineral density was seen in patients receiving standard-dose stavudine but not in those receiving low-dose stavudine. These results suggest that switching to low-dose stavudine may improve mitochondrial indices while maintaining virological suppression.

[Metabolic bone diseases]

Osteomalacia is caused by impaired vitamin D receptor (VDR) signaling, calcium deficiency, and altered bone mineralization. This can be due to insufficient sunlight exposure, malabsorption, reduced D hormone activation in chronic kidney disease, and rare alterations of VDR signaling and phosphate metabolism. Leading symptoms are bone pain, muscular cramps, and increased incidence of falls in the elderly. The adequate respective countermeasures are to optimize the daily intake of calcium and vitamin D3 and to replace active D hormone and phosphate if deficient. Osteoporosis is characterized by bone fragility fractures upon minor physical impact. Indications for diagnosis and treatment can be established by estimating the absolute fracture risk, taking into account bone mineral density, age, gender, and individual risk factors. Exercise, intervention programs to avoid falls, and specific drugs are capable of substantially reducing fracture risk even in the elderly. Secondary osteoporosis primarily requires both bone-altering medications and effective treatment of underlying diseases.

HIV infection in the elderly

In the US, an estimated 1 million people are infected with HIV, although one-third of this population are unaware of their diagnosis. While HIV infection is commonly thought to affect younger adults, there are an increasing number of patients over 50 years of age living with the condition. UNAIDS and WHO estimate that of the 40 million people living with HIV/AIDS in the world, approximately 2.8 million are 50 years and older. With the introduction of highly active antiretroviral therapy (HAART) in the mid-1990s, survival following HIV diagnosis has risen dramatically and HIV infection has evolved from an acute disease process to being managed as a chronic medical condition. As treated HIV-infected patients live longer and the number of new HIV diagnoses in older patients rise, clinicians need to be aware of these trends and become familiar with the management of HIV infection in the older patient. This article is intended for the general clinician, including geriatricians, and will review epidemiologic data and HIV treatment as well as provide a discussion on medical management issues affecting the older HIV-infected patient.

Evolution of bone mineral density in AIDS patients on treatment with zidovudine/lamivudine plus abacavir or lopinavir/ritonavir

OBJECTIVES

The aim of the study was to determine the factors that may contribute to decreases in bone mineral density (BMD) in patients with AIDS.

METHODS

This was a prospective, non-randomized study. Dual X-ray absorptiometry (DXA) was used to determine the BMD of the lumbar spine, femoral neck and distal radius in treatment-naïve HIV-infected male patients with AIDS before and after 1 year of treatment with zidovudine (ZDV)/lamivudine (3TC) plus abacavir (ABC) or lopinavir/ritonavir (LPV/r).

RESULTS

Basal DXA was performed in 50 patients with CD4 counts <200 cells/microL and/or any AIDS-defining condition. Thirty-two patients completed 1 year with full adherence (17 on ABC and 15 on LPV/r) and a second DXA was then performed. At baseline, 19% had osteopenia at the lumbar spine and 19% at the femoral neck. Low body weight was related to low BMD. After 48 weeks, BMD loss was significant at the three locations. The percentage of BMD loss at the femoral neck tended to be greater in the lopinavir group (5.3 vs. 3.2%, P=0.058). The differences became significant at the lumbar spine (5.7 vs. 2.7%, P=0.044). In the multivariate analysis, the treatment with LPV/r remained associated with bone loss at the lumbar spine.

CONCLUSIONS

Osteopenia is frequent in treatment-naïve HIV-infected men with AIDS. Bone loss is higher with LPV/r-based regimens compared with triple nucleoside reverse transcriptase inhibitors.

Alendronate with calcium and vitamin D supplementation is safe and effective for the treatment of decreased bone mineral density in HIV

BACKGROUND

Decreased bone mineral density (BMD) is prevalent in HIV-infected patients. Bisphosphonates are currently the mainstay of treatment for postmenopausal and male osteoporosis in HIV-uninfected individuals; however, their efficacy and safety in HIV-infected patients remains unclear.

METHODS

In this prospective, randomized, placebo-controlled multicenter trial, we studied the effectiveness of calcium and vitamin D supplementation with or without alendronate in improving BMD in HIV-infected subjects receiving stable antiretroviral therapy. Subjects with secondary causes of osteoporosis were excluded. The study was powered to detect differences of 3.5% between arms and to detect a moderate sex effect in percentage change in lumbar spine BMD. All dual-energy X-ray absorptiometry scans were analysed centrally, blinded by arm.

RESULTS

The 82 subjects enrolled were 71% men, 77% white, with a baseline median age of 48 years, CD4 cell count of 469 cells/mul, and lumbar spine t-score of less than 2.1; 91% had HIV-RNA levels less than 400 copies/ml, and 99% were taking antiretroviral drugs. Compared with calcium/vitamin D alone, alendronate plus calcium/vitamin D resulted in significant improvements in BMD at the lumbar spine, total hip, and trochanter, but not at the femoral neck, compared with baseline. There were trends towards significant increases in BMD values in the calcium/vitamin D group at the lumbar spine, total hip, and femoral neck. There were no apparent sex differences in the responses to therapy. Alendronate was well tolerated, without significant adverse events.

CONCLUSION

Once-weekly alendronate is safe and effective in the treatment of decreased BMD in HIV-infected patients.