Hepatitis C co-infection and severity of liver disease as risk factors for osteoporotic fractures among HIV-infected patients

HIV and fracture: Risk, assessment and intervention

OBJECTIVES

With management of comorbidity in people living with HIV (PLWH) a key component of clinical care, early loss of bone integrity and clinical fracture are recognized as important issues. This review aims to describe the epidemiology of fracture in PLWH, as well as summarizing the relative balance of factors that contribute to fracture. We also aim to describe fracture risk assessment and interventional strategies to modify the risk of fracture in this population.

RESULTS

Data from recent meta-analyses show that PLWH have significantly more fractures than the general population, with men and injecting drug users at higher risk. Modifiable factors that contribute to fracture risk in this cohort include body mass index (BMI), drug use, concurrent medications, frailty, and hepatitis C virus infection. Relating to antiretroviral therapy, current or ever tenofovir exposure has been identified as predictive of fracture but not cumulative use, and a potentially modest protective effect of efavirenz has been observed. Fracture Risk Assessment Tool scores underestimate fracture risk in PLWH with improved accuracy when HIV is considered a cause of secondary osteoporosis and bone mineral density (BMD) included.

CONCLUSION

Early consideration of risk, prompting evaluation of modifiable risk factors, frailty and falls risk with bone density imaging and prompt intervention may avert fracture in PLWH. Guidance on screening and lifestyle modification is available in international guidelines. Bisphosphonates are safe and effective in PLWH, with limited data for other agents.

Secondary Osteoporosis and Metabolic Bone Diseases

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

Effects of Hepatitis C Virus (HCV) Eradication on Bone Mineral Density in Human Immunodeficiency Virus/HCV-Coinfected Patients

BACKGROUND

Little is known about the effects of eradication of hepatitis C virus (HCV) on bone mineral density (BMD) and biomarkers of bone remodeling in human immunodeficiency virus (HIV)/HCV-coinfected patients.

METHODS

We prospectively assessed standardized BMD (sBMD) at the lumbar spine and femoral neck, World Health Organization BMD categories at both sites, and plasma concentrations of soluble receptor activator of NF-κβ ligand (sRANKL), and osteoprotegerin (OPG) at baseline (the date of initiation of anti-HCV therapy) and at 96 weeks.

RESULTS

A total of 238 patients were included. The median age was 49.5 years, 76.5% were males, 48.3% had cirrhosis, 98.3% were on antiretroviral therapy, median CD4+ cell count was 527 cells/μL, and 86.6% had HIV-1 RNA <50 copies/mL. The prevalence of osteoporosis at baseline at the lumbar spine (LS) and femoral neck (FN) was 17.6% and 7.2%, respectively. Anti-HCV therapy comprised pegylated interferon (peg-IFN) and ribavirin (RBV) plus 1 direct-acting antiviral in 53.4%, peg-IFN/RBV in 34.5%, and sofosbuvir/RBV in 12.2%. A total of 145 (60.9%) patients achieved sustained virologic response (SVR). No significant effect of SVR was observed on sBMD for the interaction between time and SVR either in the LS (P = .801) or the FN (P = .911). Likewise, no significant effect of SVR was observed in plasma levels of sRANKL (P = .205), OPG (P = .249), or sRANKL/OPG ratio (P = .123) for the interaction between time and SVR. No significant correlation was found between fibrosis by transient elastography, and LS and FN sBMD, at baseline and week 96.

CONCLUSIONS

SVR was not associated with significant changes in BMD nor biomarkers of bone remodeling in HIV/HCV-coinfected persons.

Bone methabolic disorders in HIV positive patients: a case report

Fractures in patients affected by HIV are more frequent than what is reported in patients with no retroviral diseases. Chronic infection with HIV likely contributes to increased systemic inflammation, which has been associated with increased rates of fracture. We report a case of a 56-year-old male (HIV + in treatment with Atripla) heavy worker, at the beginning affected by intra-articular proximal humerus fracture treated with endoprosthesis replacement and later by periprosthetic fracture treated with plate, screws and cerclages. Follow up was performed with clinical evaluation (ROM, VAS, Quick Dash, ASES, Simple shoulder test, UCLA Score, Constant score) and shoulder radiographs. Bone metabolism disorders in HIV patients lead to low BMD values, changes in bone turnover markers, and histomorphometric abnormalities, especially when HIV is present along with HCV or other hepatopathies. Additional therapy with bisphosphonate and Vitamin D should always be carried out when possible to prevent such types of orthopaedic complications. (www.actabiomedica.it)

HCV co-infection among people living with HIV Is associated with Higher fracture risk

INTRODUCTION

The purpose of this study was to predict the 10-year risk of fracture among people living with HIV (PLWH) using FRAX™, and to determine the risk factors related to a high probability of fractures.

METHODOLOGY

This study consisted of 288 subjects aged 40 years and above. The ten-year probability of major osteoporotic fractures (MOF) and hip fractures was assessed using the FRAX™ algorithm with bone mineral density (BMD) data. A logistic regression was used to determine risk factors related to a high probability of major osteoporotic fracture and hip fracture.

RESULTS

The median 10-year probability of fracture was 3.7% (IQR 2.2-6.2) for MOF and 0.8% (IQR 0.3-2.5) for hip fractures. In addition to old age, previous fracture history, and low T-scores, HCV co-infection was associated with a higher risk of hip fractures in PLWH (AOR: 4.3, 95% CI: 1.29-14.33). Old age and low T-scores were also associated with a high probability of MOF.

CONCLUSIONS

HCV co-infection among PLWH is associated with a higher risk of hip fracture. Sustained efforts in terms of pharmacologic and non-pharmacologic interventions in PLWH are necessary to prevent osteoporotic fractures, especially in those with HCV co-infections.

Bone fracture among people living with HIV: A systematic review and meta-regression of prevalence, incidence, and risk factors

Introduction

People living with HIV (PLWH) had a higher prevalence and incidence rate of bone fracture compared to general population. Although several studies have explored this phenomenon, the prevalence and incidence rate of fracture were varied.

Objective

The aim of the study is to determine and analyze the pooled prevalence, incidence rate of fracture and fracture risk factors among people living with HIV (PLWH).

Methods

PubMed, Cochrane Library, CINAHL with full Text, and Medline databases for studies published up to August 2019 were searched. Studies reporting the prevalence or incidence of fracture among PLWH were included. Study quality was assessed using the Joanna Briggs Institute (JBI) appraisal tool. A meta-analysis with random-effects model was performed to determine pooled estimates of prevalence and incidence rates of fracture. A meta-regression was performed to determine the source of heterogeneity.

Results

The pooled estimated prevalence of fracture among PLWH was 6.6% (95% CI: 3.8–11.1) with pooled odds ratio of 1.9 (95%CI: 1.1–3.2) compared to the general population. The pooled estimates of fracture incidence were 11.3 per 1000 person-years (95% CI: 7.9–14.5) with incidence rate ratio (IRR) of 1.5 (95% CI: 1.3–1.8) compared to the general population. Risk factors for fracture incidence were older age (aHR 1.4, 95% CI: 1.3–1.6), smoking (aHR 1.3, 95% CI: 1.1–1.5), HIV/HCV co-infection (aHR 1.6, 95% CI: 1.3–1.9), and osteoporosis (aHR 3.3, 95% CI: 2.2–5.1).

Conclusions

Our finding highlights a higher risk of fracture among PLWH compared to the general population. Osteoporosis, smoking and HIV/HCV coinfection as the significant modifiable risk factors should be prioritized by the HIV health providers when care for PLWH.

Bone mineral density and trabecular bone score in treatment-naïve patients with non-cirrhotic hepatitis C virus infection

We studied 112 treatment-naïve chronic HCV patients without cirrhosis, and we found that, especially HCV+ postmenopausal women, they had lower TBS and BMD values than healthy controls. This suggests that HCV infection is an independent risk factor for osteoporosis, and therefore, screening for osteoporosis in postmenopausal HCV+ women should be considered.

PURPOSE

To know whether patients in earlier stages of chronic HCV infection are at increased risk of developing low bone mass and bone microarchitectural changes and whether there is an association between bone metabolism and the severity of the liver disease.

METHODS

We studied 112 treatment-naïve chronic HCV outpatients and 233 healthy age- and sex-matched controls. Bone mineral density (BMD) and trabecular bone score (TBS) were assessed by DXA. Serum 25(OH)D, PTH, P1NP, and CTX were determined by electrochemiluminescence.

RESULTS

TBS values were significantly lower in HCV patients than in controls, both considering the population as a whole (1.337 ± 0.119 vs. 1.377 ± 0.122; p < 0.005) and after stratifying by sex (1.347 ± 0.12 vs. 1.381 ± 0.13 in men and 1.314 ± 0.10 vs. 1.369 ± 0.11 in women). The difference remained significant (p < 0.0001 in all cases) after adjusting for confounders. BMD was also lower in HCV patients (lumbar spine, 0.935 ± 0.151 vs. 0.991 ± 0.143 g/cm², p 0.001; femoral neck, 0.764 ± 0.123 vs. 0.818 ± 0.123 g/cm², p 0.0001; total hip, 0.926 ± 0.148 vs. 0.963 ± 0.132 g/cm², p 0.02), although, after adjustment, differences kept a clear trend towards statistical significance in women at the lumbar spine and femoral neck. However, in men and at the total hip in women, differences were no longer significant. We find no relationship between these parameters and the severity of the disease. No significant difference was observed in PTH and 25OHD status after adjustment. Finally, serum P1NP, but not CTX, was higher in HCV patients.

CONCLUSIONS

Our findings suggest that HCV infection is an independent risk factor for osteoporosis, especially among postmenopausal women. Therefore, the appropriateness of screening for osteoporosis in postmenopausal HCV-positive women should be considered.

The Differential Effects of Human Immunodeficiency Virus and Hepatitis C Virus on Bone Microarchitecture and Fracture Risk

Background

Human immunodeficiency virus (HIV)/hepatitis C virus (HCV)-coinfected individuals have a significantly greater osteoporotic fracture risk than HIV-monoinfected persons, despite the fact that HIV/HCV coinfection has not been associated with lower bone mineral density (BMD) than HIV or HCV alone. To evaluate if changes in bone microarchitecture, measured by trabecular bone score (TBS), could explain these differences, we performed a prospective, cross-sectional cohort study of virologically suppressed HIV-infected subjects, untreated HCV-infected subjects, HIV/HCV-coinfected subjects, and uninfected controls.

Methods

We enrolled 532 male subjects: 57 HIV/HCV coinfected, 174 HIV infected, 123 HCV infected, and 178 controls. We conducted analysis of covariance comparing BMD and TBS between groups, controlling for age, race, body mass index, and smoking. We used linear regression to evaluate predictors of BMD and TBS and evaluated the effects of severity of HCV infection and tenofovir disoproxil fumarate use.

Results

Despite both infections being associated with decreased BMD, only HCV, but not HIV, was associated with lower TBS score. Also, HIV/HCV-coinfected subjects had lower TBS scores than HIV-monoinfected, HCV-monoinfected, and uninfected subjects. Neither the use of TDF or HCV viremia nor the severity of HCV liver disease was associated with lower TBS.

Conclusions

HCV infection is associated with microarchitectural changes at the lumbar spine as assessed by the low TBS score, suggesting that microstructural abnormalities underlie some of the higher fracture risk in HCV infection. TBS might improve fracture risk prediction in HCV infection.

Relationship Between Vertebral Fractures, Bone Mineral Density, and Osteometabolic Profile in HIV and Hepatitis B and C-Infected Patients Treated With ART

Objective: The purpose of our study was to evaluate the alterations of bone metabolism and the prevalence of vertebral fractures in the population with HIV and hepatitis B and C seropositivity in treatment with antiretroviral drugs (HAART). Methods: We selected 83 patients with diagnosis of HIV, HBV, HCV infection. In all these patients biochemical examinations of phospho-calcium metabolism and a densitometry of lumbar spine were performed. We also evaluated lateral spine X-rays in order to analyze the presence of vertebral deformities and to define their severity. As a control group we analyzed the prevalence of vertebral fractures in a group of 40 non-infectious patients. Results: We selected 82 seropositive patients, 46 males and 37 females, with a median age of 55 ± 10 years. Out of these patients, 55 were infected by HIV, 12 were infected by HBV, 11 presented HIV and HCV co-infection and 4 were HCV+. The prevalence of hypovitaminosis D in the studied population was 53%, while the prevalence of osteoporosis and osteopenia was 14 and 48%, respectively. The average T-score in the fractured population was -1.9 SD. The viral load and the CD4+ cell count were respectively, directly, and inversely correlated with the number and severity of vertebral fractures. Antiretroviral therapy regimen containing TDF and PI was a significant determinant of the presence of vertebral deformities. The use of these drugs was also associated with lower levels of vitamin D and higher bone turnover levels compared to other antiretroviral drugs. Conclusions: HIV patients suffer from bone fragility, particularly at spine, independently by the level of bone mineral density. In this population, the T-score threshold for the risk of fracture is higher than that usually used in general population. For this reason, it would be indicated to perform an X-ray of the spine in order to detect vertebral deformities even in patients with a normal or slighlty reduced bone mineral density.

Endocrinological aspects of HIV infection

PURPOSE

Patients with human immunodeficiency virus (HIV) are living longer with effective antiretroviral therapies and are enjoying near normal life span. Therefore, they are encountering endocrine issues faced by the general population along with those specific to HIV infection. The purpose of this article is to review the common endocrine aspects of HIV infection, and the early detection and management strategies for these complications.

METHODS

Recent literature on HIV and endocrine disease was reviewed.

RESULTS

HIV can influence endocrine glands at several levels. Endocrine glandular function may be altered by the direct effect of HIV viral proteins, through generation of systemic and local cytokines and the inflammatory response and via glandular involvement with opportunistic infections and HIV-related malignancies. Endocrine disorders seen in people with HIV include metabolic issues related to obesity such as diabetes, hyperlipidemia, lipohypertrophy, lipoatrophy and lipodystrophy and contribute significantly to quality of life, morbidity and mortality. In addition, hypogonadism, osteopenia and osteoporosis are also more prevalent in the patients with HIV. Although disorders of hypothalamic-pituitary-adrenal axis resulting in adrenal insufficiency can be life threatening, these along with thyroid dysfunction are being seen less commonly in the antiretroviral therapy (ART) era. ARTs have greatly improved life expectancy in people living with HIV but can also have adverse endocrine effects.

CONCLUSIONS

Clinicians need to have a high index of suspicion for endocrine abnormalities in people with HIV as they can be potentially life threatening if untreated. Endocrine evaluation should be pursued as in the general population, with focus on prevention, early detection and treatment to improve quality of life and longevity.

Use of quantitative ultrasound as bone mineral density evaluation in an Italian female population living with HIV: A real-life experience

This is a multicenter cross-sectional study where we aimed to detect the rate of osteopenia/osteoporosis in an HIV female population (WLWHIV) by means of "heel quantitative ultrasound" (QUS) measurement. We enrolled 273 patients, mean age 48.1 years, 36% menopausal, 96% on combination antiretroviral therapy (cART). Calcaneal measure of bone mass index by QUS revealed osteopenia and osteoporosis in 76 (27.8%) and 16 (5.9%) WLWHIV. Our data underline the correlation between low QUS parameters and traditional risk factors for osteoporosis rather than with cART exposure, thus suggesting the crucial importance of detection and correction of traditional risk factors for osteoporosis in WLWHIV.

Metabolic and Cardiovascular Complications in HIV/HCV-Co-infected Patients

PURPOSE OF REVIEW

Fifteen to thirty percent of HIV-infected persons in North America and Europe are co-infected with chronic hepatitis C (HCV). The latter is associated with a significant number of extra-hepatic metabolic complications that could compound HIV-associated increased cardiovascular risk. This article reviews the basic science and epidemiologic and clinical evidence for increased cardio-metabolic risk among HIV/HCV-co-infected patients and discusses potential underlying mechanisms. We will finally review the impact of control of HCV viremia on the cardio-metabolic morbidity and mortality of HIV/HCV-co-infected patients.

RECENT FINDINGS

HCV infection is associated with a number of immune-related complications such as cryoglobulinemia but also metabolic complications including dyslipidemias, hepatic steatosis, insulin resistance, diabetes, and chronic kidney disease. The incidence of these complications is higher among HIV-co-infected patients and might contribute to increased mortality. The potential mechanisms of increased cardiovascular risk among HIV/HCV-co-infected subjects include endothelial dysfunction, chronic inflammation and immune activation, the cardio-metabolic effects of HCV-induced hepatic steatosis and fibrosis or insulin resistance, and chronic kidney disease. However, epidemiologic studies show discordant findings as to whether HCV co-infection further increases the risk of atherosclerotic cardiovascular diseases (acute myocardial infarctions and strokes) among HIV-infected patients. Nonetheless, successful treatment of HCV is associated with significant improvements in cardio-metabolic risk factors including diabetes mellitus. HCV co-infection is associated with a higher incidence of metabolic complications-and likely increased risk of cardiovascular events-that might contribute to increased mortality in HIV. These appear to improve with successful HCV therapy.

Protecting bone in long-term HIV positive patients receiving antiretrovirals

INTRODUCTION

As the population of people living with HIV ages, the increase in non-AIDs morbidities is expected to increase in parallel. Maintaining bone health in those with HIV will be an important area of focus for the HIV clinician to prevent the morbidity and mortality associated with fragility fractures, the principal clinical sequela of low bone mineral density (BMD). Rates of fractures and prevalence of low bone mineral density, a risk factor for future fragility fractures, are already increased in the HIV positive population.

AREAS COVERED

This review examines the strategies to maintain bone health in those living with HIV from screening through to managing those with established low BMD or fracture, including the role for choice of or modification of antiretroviral therapy to maintain bone health. Expert commentary: The increasing complexity of managing bone health in the age of succesful antiretroviral therapy and an aging patient population as well as future perspectives which may help achieve the long term aim of minimising the impact of low BMD in those with HIV are discussed and explored.

A syndemic approach to assess the effect of substance use and social disparities on the evolution of HIV/HCV infections in British Columbia

BACKGROUND

Co-occurrence of social conditions and infections may affect HIV/HCV disease risk and progression. We examined the changes in relationship of these social conditions and infections on HIV and hepatitis C virus (HCV) infections over time in British Columbia during 1990-2013.

METHODS

The BC Hepatitis Testers Cohort (BC-HTC) includes ~1.5 million individuals tested for HIV or HCV, or reported as a case of HCV, HIV, HBV, or tuberculosis linked to administrative healthcare databases. We classified HCV and HIV infection status into five combinations: HIV-/HCV-, HIV+monoinfected, HIV-/HCV+seroconverters, HIV-/HCV+prevalent, and HIV+/HCV+.

RESULTS

Of 1.37 million eligible individuals, 4.1% were HIV-/HCV+prevalent, 0.5% HIV+monoinfected, 0.3% HIV+/HCV+ co-infected and 0.5% HIV-/HCV+seroconverters. Overall, HIV+monoinfected individuals lived in urban areas (92%), had low injection drug use (IDU) (4%), problematic alcohol use (4%) and were materially more privileged than other groups. HIV+/HCV+ co-infected and HIV-/HCV+seroconverters were materially most deprived (37%, 32%), had higher IDU (28%, 49%), problematic alcohol use (14%, 17%) and major mental illnesses (12%, 21%). IDU, opioid substitution therapy, and material deprivation increased in HIV-/HCV+seroconverters over time. In multivariable multinomial regression models, over time, the odds of IDU declined among HIV-/HCV+prevalent and HIV+monoinfected individuals but not in HIV-/HCV+seroconverters. Declines in odds of problematic alcohol use were observed in HIV-/HCV+seroconverters and coinfected individuals over time.

CONCLUSIONS

These results highlight need for designing prevention, care and support services for HIV and HCV infected populations based on the evolving syndemics of infections and social conditions which vary across groups.

Eradication of hepatitis C virus and non-liver-related non-acquired immune deficiency syndrome-related events in human immunodeficiency virus/hepatitis C virus coinfection

We assessed non-liver-related non-acquired immunodeficiency syndrome (AIDS)-related (NLR-NAR) events and mortality in a cohort of human immunodeficiency virus (HIV)/hepatitis C virus (HCV)-coinfected patients treated with interferon (IFN) and ribavirin (RBV), between 2000 and 2008. The censoring date was May 31, 2014. Cox regression analysis was performed to assess the adjusted hazard rate (HR) of overall death in responders and nonresponders. Fine and Gray regression analysis was conducted to determine the adjusted subhazard rate (sHR) of NLR deaths and NLR-NAR events considering death as the competing risk. The NLR-NAR events analyzed included diabetes mellitus, chronic renal failure, cardiovascular events, NLR-NAR cancer, bone events, and non-AIDS-related infections. The variables for adjustment were age, sex, past AIDS, HIV transmission category, nadir CD4⁺ T-cell count, antiretroviral therapy, HIV RNA, liver fibrosis, HCV genotype, and exposure to specific anti-HIV drugs. Of the 1,625 patients included, 592 (36%) had a sustained viral response (SVR). After a median 5-year follow-up, SVR was found to be associated with a significant decrease in the hazard of diabetes mellitus (sHR, 0.57; 95% confidence interval [CI], 0.35-0.93; P = 0.024) and decline in the hazard of chronic renal failure close to the threshold of significance (sHR, 0.43; 95% CI, 0.17-1.09; P = 0.075).

CONCLUSION

Our data suggest that eradication of HCV in coinfected patients is associated not only with a reduction in the frequency of death, HIV progression, and liver-related events, but also with a reduced hazard of diabetes mellitus and possibly of chronic renal failure. These findings argue for the prescription of HCV therapy in coinfected patients regardless of fibrosis stage. (Hepatology 2017;66:344-356).

Fracture Prediction With Modified-FRAX in Older HIV-Infected and Uninfected Men

BACKGROUND

FRAX is a validated, computer-based clinical fracture risk calculator that estimates the 10-year risk of major osteoporotic (clinical spine, forearm, hip, or shoulder) fracture, and hip fracture alone. It is widely used for decision making in fracture prevention, but it may underestimate the risk in HIV-infected individuals. Some experts recommend considering HIV as a cause of secondary osteoporosis when calculating FRAX in HIV-infected individuals.

METHODS

From the Veterans Aging Cohort Study Virtual Cohort, we included 24,451 HIV-infected and uninfected men aged 50-70 years with complete data in the year 2000 to approximate all but 2 factors (ie, history of secondary osteoporosis and parental hip fracture) for modified-FRAX calculation without bone density and 10-year observational data for incident fragility fracture. The accuracy of the modified-FRAX calculation was compared by the observed/estimated (O/E) ratios of fracture by HIV status.

RESULTS

The accuracy of modified-FRAX was less for HIV-infected [O/E = 1.62, 95% confidence interval (CI) 1.45 to 1.81] than uninfected men (O/E = 1.29, 95% CI: 1.19 to 1.40), but improved when HIV was included as a cause of secondary osteoporosis (O/E = 1.20, 95% CI: 1.08 to 1.34). However, only 3%-6% of men with incident fractures were correctly identified by the modified-FRAX using accepted FRAX thresholds for pharmacologic therapy.

CONCLUSIONS

Modified-FRAX underestimated the fracture rates more in older HIV-infected than in otherwise similar uninfected men. The accuracy improved when HIV was included as a cause of secondary osteoporosis, but it still performed poorly for case finding. Further studies are necessary to determine how to use FRAX or define an HIV-specific index to risk stratify for screening and treatment in older HIV-infected individuals.

Bone health in HIV and hepatitis B or C infections

Chronic infections with human immunodeficiency virus (HIV), hepatitis B virus (HBV) or hepatitis C virus (HCV) add to age-dependent bone loss and may contribute to lower bone strength in the elderly. In this review, we report recent highlights on the epidemiology of bone fragility in chronic viral infections with HIV, HCV and HBV, its physiopathology and discuss the interference of antiviral therapies with bone metabolism. Chronic infections influence bone through the interactions between risk factors for bone fragility and falls (which are highly prevalent in infected patients), virus activity and antiviral drugs. HIV-infected patients are at increased risk of fracture and the risk is higher in cases of co-infection with HIV and untreated chronic viral hepatitis. In HIV patients, the majority of bone loss occurs during virus activity and at initiation of antiretroviral therapy (ART). However, long-term elderly HIV-infected patients on successful ART display bone microstructure alterations only partially captured by dual energy X-ray absorptiometry (DXA). Bone loss is associated with an increase of bone resorption, reflecting the upregulation of the receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG) pathways via a crosstalk between virus activity, inflammation and the immune system. The use of some antiviral drugs, such as tenofovir (controlling both HBV and HIV infections) or protease inhibitors, may be associated with higher bone toxicity. The reduction of tenofovir plasma concentrations with the implementation of tenofovir alafenamide (TAF) attenuates bone mineral density (BMD) loss but it remains unknown whether it will contribute to reducing fracture risk in long-term HIV-treated patients. Moreover, to what extent the new direct-acting agents for treatment of HCV, including nucleotide inhibitors and protease inhibitors, may affect bone health similarly as ART in HIV should be investigated.

Do people with HIV infection have a higher risk of fracture compared with those without HIV infection?

PURPOSE OF REVIEW

This review details recent findings that inform the prevalence and incidence of fractures in people living with HIV (PLWH) and examines the effects of HIV infection and antiretroviral therapy (ART), as well as demographics and traditional risk factors on fractures. As antiretroviral guidelines have recently changed to recommend the introduction of ART at diagnosis of HIV infection, the long-term effects of ART on bone health and fracture risk need to be better understood.

RECENT FINDINGS

It is apparent that both the effects of HIV infection alone and initiation of ART are associated with significant bone loss in individuals with HIV infection, resulting in osteopenia and osteoporosis. The clinical consequence of low bone mineral density is a greater risk of fragility fractures that are more common in older HIV patients, and those on ART. Frailty occurs at a prevalence of about 10% (about twice that of the general population), and the increased propensity of falls results in greater fracture prevalence, morbidity and mortality.

SUMMARY

This review examines data from recent cohort studies and clinical trials to inform a better understanding of the complex relationship between the effects of HIV infection, ART and demographics on fractures in PLWH.

HIV infection and bone disease

The success of antiretroviral therapy in treating HIV infection has greatly prolonged life expectancy in affected individuals, transforming the disease into a chronic condition. A number of HIV-associated non-AIDS comorbidities have emerged in the ageing HIV-infected population, including osteoporosis and increased risk of fracture. The pathogenesis of fracture is multifactorial with contributions from both traditional and HIV-specific risk factors. Significant bone loss occurs on initiation of antiretroviral therapy but stabilizes on long-term therapy. Fracture risk assessment should be performed in HIV-infected individuals and bone mineral density measured when indicated. Lifestyle measures to optimize bone health should be advised and, in individuals at high risk of fracture, treatment with bisphosphonates considered.

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.

Mechanisms of bone disease in HIV and hepatitis C virus: impact of bone turnover, tenofovir exposure, sex steroids and severity of liver disease

OBJECTIVE

Both HIV and hepatitis C virus (HCV) infections are associated with higher osteoporotic fracture risk. Increased bone turnover, liver fibrosis, tenofovir (TDF) use or hormonal imbalances are possible underlying mechanisms.

DESIGN

This prospective, cross-sectional study assessed 298 male volunteers with either virologically suppressed HIV or untreated HCV mono-infections, HIV/HCV co-infection and noninfected controls.

METHODOLOGY

Study participants underwent bone mineral density (BMD) by dual-energy x-ray absorptiometry and measurement of bone turnover markers [BTM: C-telopeptide (CTX) and osteocalcin (OC)], insulin-like growth factor-1 (IGF-1), the sex steroids testosterone (T) and estradiol (E2), and the aspartate aminotransferase-to-platelet ratio index (APRI). Impact of HIV and HCV status on BMD was evaluated in multivariate models adjusting for APRI score, BTM, TDF exposure, IGF-1, and sex steroids.

RESULTS

HIV and HCV status independently predicted lower BMD, controlling for age, race, BMI, and smoking (P = 0.017 and P = 0.010, respectively), whereas APRI did not (P = 0.84). HIV was associated with increased bone resorption (CTX: P < 0.001) and formation (OC: P = 0.014), whereas HCV infection was not associated with CTX (P = 0.30) or OC (P = 0.36). TDF exposure was associated with lower BMD (P < 0.01). IGF-1 was significantly decreased in HCV and increased in HIV. Tumor necrosis factor-α (P = 0.98), IGF-1 (P = 0.80), bioavailable T (P = 0.45) and E2 (P = 0.27) were not associated with BMD and did not attenuate the impact of HIV or HCV on BMD.

CONCLUSION

HIV and TDF exposure decrease BMD through increased bone turnover, although the lower BMD in HCV is not explained by a high turnover state. Neither virus' effect on BMD is likely mediated through increased inflammation, liver fibrosis, IGF-1, or sex steroids.

Increased Fracture Incidence in Middle-Aged HIV-Infected and HIV-Uninfected Women: Updated Results From the Women's Interagency HIV Study

BACKGROUND

We previously reported that fracture incidence rates did not differ by HIV status among predominantly premenopausal Women's Interagency HIV Study participants. We now conduct a follow-up study with 5 additional observation years to further characterize fracture risk associated with HIV infection in women as they age.

METHODS

We measured time to first new fracture at any site in 2375 (1713 HIV-infected and 662 HIV-uninfected) Women's Interagency HIV Study participants, with median 10-year follow-up. Fractures were self-reported semiannually. Proportional hazards models assessed predictors of incident fracture.

RESULTS

At index visit, HIV-infected women were older [median age of 40 years (IQR: 34-46) vs. 35 (27-43), P < 0.0001] and more likely to be postmenopausal, hepatitis C virus infected, and weigh less than HIV-uninfected women. Among HIV-infected women, mean CD4 count was 480 cells per microliter and 63% were taking highly active antiretroviral therapy. Unadjusted incidence rates of any fracture were higher in HIV-infected than in HIV-uninfected women [2.19/100 person-years (py) vs. 1.54/100 py, P = 0.002]. In multivariate models, HIV status, older age, white (vs. black) race, prior fracture, history of cocaine use, and history of injection drug use were significant predictors of incident fracture. Among HIV-infected women, age, white race, prior fracture, smoking, and prior AIDS were predictors of new fracture.

CONCLUSIONS

Middle-aged HIV-infected women had a higher adjusted fracture rate than HIV-uninfected women. Cocaine use and injection drug use were also associated with a greater risk of incident fracture. Further research is needed to understand whether the risk of fracture associated with cocaine use relates to increased rate of falls or direct effects on bone metabolism.

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.

Vitamin D and Osteoporosis in HIV/HCV Coinfected Patients: A Literature Review

Vitamin D deficiency further increases the risk of osteoporosis in HIV-positive patients coinfected with hepatitis C virus (HCV); however, it is still unclear whether HCV-related increased fracture risk is a function of the severity of liver disease. The aim of this review was to identify studies on associative vitamin D deficiency patterns in high-risk populations such as HIV/HCV coinfected patients. We did this by searching MEDLINE and EMBASE databases, from inception to August 2014, and included bibliographies. The final 12 articles selected are homogeneous in terms of age but heterogeneous in terms of sample size, participant recruitment, and data source. Most of the HIV/HCV coinfected patients have less than adequate levels of vitamin D. After reviewing the selected articles, we concluded that vitamin D deficiency should be regarded as a continuum and that the lower limit of the ideal range is debatable. We found that vitamin D deficiency might influence liver disease progression in HIV/HCV coinfected patients. Methodological issues in evaluating vitamin D supplementation as a relatively inexpensive therapeutic option are discussed, as well as the need for future research, above all on its role in reducing the risk of HCV-related fracture by modifying liver fibrosis progression.

HIV-related metabolic comorbidities in the current ART era

Despite effective antiretroviral therapy (ART), HIV-infected individuals have residual chronic immune activation that contributes to the pathogenesis of HIV infection. This immune system dysregulation is a pathogenic state manifested by very low naïve T-cell numbers and increased terminally differentiated effector cells that generate excessive proinflammatory cytokines with limited functionality. Immune exhaustion leaves an individual at risk for accelerated aging-related diseases, including renal dysfunction, atherosclerosis, diabetes mellitus, and osteoporosis. We highlight research that clarifies the role of HIV, ART, and other factors that contribute to the development of these diseases among HIV-infected persons.

Bone Density and Fractures in HIV-infected Postmenopausal Women: A Systematic Review

With the development of effective antiretroviral therapy, HIV-infected women are living longer and transitioning through menopause. The purpose of our study was to systematically examine the evidence that menopause is an additional risk predictor for osteoporosis and fractures in HIV-infected women. Electronic databases were searched for studies of low bone density or fractures in HIV-infected postmenopausal women. Studies that met the inclusion criteria (n = 10) were appraised using a validated quality assessment tool. The majority of studies were rated as good quality and the remaining were fair. The prevalence of osteoporosis reported in these studies ranged from 7.3% to 84% and 0.7% to 23% in HIV-infected and uninfected postmenopausal women, respectively. In the two qualifying studies, postmenopausal status was not a predictor of fractures in HIV-infected women. Findings suggest that HIV care providers should accurately assess postmenopausal status and modifiable risk factors for osteoporosis in all older HIV-infected women.

Bone alterations associated with HIV

HIV infection and initiation of antiretroviral therapy (ART) have been consistently associated with decreased bone mineral density (BMD), with growing evidence linking HIV to an increased risk of fracture. This is especially concerning with the expanding number of older persons living with HIV. Interestingly, recent data suggest that HIV-infected children and youth fail to achieve peak BMD, possibly increasing their lifetime risk of fracture. Elucidating the causes of the bone changes in HIV-positive persons is challenging because of the multifactorial nature of bone disease in HIV, including contribution of the virus, immunosuppression, ART toxicity, and traditional osteoporosis risk factors, such as age, lower weight, tobacco, and alcohol use. Thus, practitioners must recognize the risk of low BMD and fractures and appropriately screen patients for osteoporosis if risk factors exist. If fractures do occur or elevated fracture risk is detected through screening, treatment with bisphosphonate medications appears safe and effective in the HIV+population.

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.

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.

Osteoporosis and fracture risk associated with HIV infection and treatment

Osteoporosis has emerged as an important co-morbidity of HIV infection and a modest increase in fracture risk has been documented. Bone loss from the spine and hip occurs after initiation of antiretroviral therapy but most data indicate that bone mineral density is stable in HIV-infected individuals established on long-term antiretroviral therapy. Assessment of fracture probability should be performed in individuals who have clinical risk factors for fracture. Adequate dietary calcium intake and vitamin D status should be ensured and in individuals with a high fracture probability, bisphosphonate therapy may be appropriate.

Bones, Fractures, Antiretroviral Therapy and HIV

The course of HIV infection has been dramatically transformed by the success of antiretroviral therapy from a universally fatal infection to a manageable chronic disease. With these advances in HIV disease management, age-related comorbidities, including metabolic bone disease, have become more prominent in the routine care of persons living with HIV infection. Recent data have highlighted the role of HIV infection, initiation of antiretroviral therapy, and hepatitis C virus coinfection in bone mineral density loss and fracture incidence. Additionally, the underlying mechanism for the development of metabolic bone disease in the setting of HIV infection has received considerable attention. This review highlights recently published and presented data and synthesizes the current state of the field. These data highlight the need for proactive prevention for fragility fractures.