Controlled HIV viral replication, not liver disease severity associated with low bone mineral density in HIV/HCV co-infection

Administration of zoledronic acid alleviates osteoporosis in HIV patients by suppressing osteoclastogenesis via regulating RANKL expression

Background

Osteoporosis is a common phenomenon in HIV patients on tenofovir treatment, but its underlying mechanisms remain to be explored.

Methods

Quantitative real-time PCR was performed to analyze the expression of miR-302, miR-101, miR-145 and osteoclast-specific genes in the serum of HIV patients treated with tenofovir and ZOL. ELISA was used to evaluate the expression of RANKL, SMAD3 and PRKACB in the serum of these patients. Luciferase assay was carried out to explore the inhibitory effects of miR-302, miR-101 and miR-145 on the expression of PRKACB, RANKL and SMAD3, respectively. Western blot was used to examine the expression of genes involved in NF‑κB and JNK signaling pathways.

Results

ZOL treatment significantly suppressed the expression of CTx and osteocalcin in HIV patients treated with tenofovir. The BMD loss of HIV patients treated with tenofovir was effectively hindered by ZOL treatment. Mechanistically, the expression of miR-302, miR-101, miR-145, RANKL, SMAD3 and PRKACB in the serum was remarkably activated by ZOL treatment. Luciferase assays showed that miR-302, miR-101 and miR-145 effectively suppressed the expression of PRKACB, RANKL and SMAD3, respectively, through binding to their 3′ UTR. Furthermore, ZOL treatment notably restored the normal expression of osteoclast‑specific genes while activating NF‑κB and JNK signaling pathways.

Conclusion

The findings of this study demonstrated that administration of ZOL suppressed the expression of RANKL via modulating signaling pathways of miR-101-3p/RANKL, miR-302/PRKACB/RANKL and miR-145/SMAD3/RANKL. Furthermore, down-regulated expression of RANKL by ZOL treatment alleviated osteoporosis in HIV-positive subjects treated with tenofovir.

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.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

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.

Effects of Pegylated Interferon/Ribavirin on Bone Turnover Markers in HIV/Hepatitis C Virus-Coinfected Patients

HIV/hepatitis C virus (HCV) patients have a 3-fold increased fracture incidence compared to uninfected patients. The impact of HCV therapy on bone health is unclear. We evaluated bone turnover markers (BTM) in well-controlled (HIV RNA <50 copies/ml) HIV/HCV-coinfected patients who received pegylated interferon-α and ribavirin (PEG-IFN/RBV) in ACTG trial A5178. Early virologic responders (EVR: ≥2 log HCV RNA drop at week 12) continued PEG-IFN/RBV and non-EVRs were randomized to continuation of PEG-IFN alone or observation. We assessed changes in C-terminal telopeptide of type 1 collagen (CTX; bone resorption marker) and procollagen type I intact N-terminal propeptide (P1NP; bone formation marker), and whether BTM changes were associated with EVR, complete early virologic response (cEVR: HCV RNA <600 IU/ml at week 12), or PEG-IFN treatment. A total of 192 subjects were included. After 12 weeks of PEG-IFN/RBV, CTX and P1NP decreased: −120 pg/ml and −8.48 μg/liter, respectively (both p < 0.0001). CTX declines were greater in cEVR (N = 91; vs. non-cEVR (N = 101; p = 0.003). From week 12 to 24, CTX declines were sustained among EVR patients who continued PEG-IFN/RBV (p = 0.027 vs. non-EVR) and among non-EVR patients who continued PEG-IFN alone (p = 0.022 vs. Observation). Median decreases of P1NP in EVR vs. non-EVR were similar at weeks 12 and 24. PEG-IFN-based therapy for chronic HCV markedly reduces bone turnover. It is unclear whether this is a direct IFN effect or a result of HCV viral clearance, or whether they will result in improved bone mineral density. Further studies with IFN-free regimens should explore these questions.

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.

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

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

Prevalence and predictors of low bone mineral density and fragility fractures among HIV-infected patients at one Italian center after universal DXA screening: sensitivity and specificity of current guidelines on bone mineral density management

Low bone mineral density (BMD) is frequent in HIV infection regardless of the use of antiretroviral therapy (ART). Uncertainties remain, however, as to when in HIV infection BMD screening should be performed. We designed a prospective study to estimate the efficacy of universal BMD screening by dual-energy X-ray absorptiometry (DXA). Since April 2009 through March 2011, HIV patients attending our Center were offered femoral/lumbar DXA to screen BMD. Low BMD for chronological age, that is significant osteopenia, was defined as a Z-score ≤ -2.0 at femur and lumbar spine. Nontraumatic bone fractures (NTBFs) were evaluated. The final sample included 163 patients. A Z-score ≤ -2.0 at any site was observed in 19.6% of cases: among these, 18.8% had no indication to DXA using current Italian HIV guidelines for BMD screening. A lower femoral Z-score was independently associated with lower BMI, AIDS diagnosis, HCV co-infection, antiretroviral treatment, and NTBFs; a lower lumbar Z-score with age, BMI, Nadir CD4 T-cell counts, and NTBFs. Prevalence of NTBFs was 27.0%, predictors being male gender, HCV co-infection, and lower femoral Z-scores. Our results suggest that measuring BMD by DXA in all HIV patients regardless of any further specification may help retrieving one-fifth of patients with early BMD disorders not identified using current criteria for selective screening of BMD.

Structural Bone Deficits in HIV/HCV-Coinfected, HCV-Monoinfected, and HIV-Monoinfected Women

BACKGROUND

Coinfection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) is associated with reduced bone mineral density (BMD) and increased fracture rates, particularly in women. The structural underpinnings for skeletal fragility in coinfected women have not been characterized. We used tibial peripheral quantitative computed tomography to evaluate skeletal parameters in women, by HIV/HCV status.

METHODS

We conducted a cross-sectional study among 50 HIV/HCV-coinfected, 51 HCV-monoinfected, and 50 HIV-monoinfected women. Tibial volumetric BMD and cortical dimensions were determined with peripheral quantitative computed tomography. Race-specific z scores for age were generated using 263 female reference participants without HIV infection or liver disease.

RESULTS

Coinfected participants had lower mean z scores for trabecular volumetric BMD (-0.85), cortical volumetric BMD (-0.67), cortical area (-0.61), and cortical thickness (-0.77) than reference participants (all P < .001). The smaller cortical dimensions were due to greater mean z scores for endosteal circumference (+0.67; P < .001) and comparable z scores for periosteal circumference (+0.04; P = .87). Trabecular volumetric BMD was lower in coinfected than in HCV- or HIV-monoinfected participants. HCV-infected women with stage 3-4 liver fibrosis had lower mean z scores for trabecular volumetric BMD, cortical thickness, and total hip BMD those with stage 0-2 fibrosis.

CONCLUSIONS

Compared with healthy reference patients, HIV/HCV-coinfected women had decreased tibial trabecular volumetric BMD, diminished cortical dimensions, and significant endocortical bone loss.

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.

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.

Bone mineral density and bone turnover in non-cirrhotic patients with chronic hepatitis C and sustained virological response to antiviral therapy with peginterferon-alfa and ribavirin

Patients with chronic hepatitis C have low bone mineral density and increased bone resorption related to serum transaminase levels. Elevated serum soluble tumor necrosis factor (sTNFR-55) receptor levels may play a role in the bone mass loss in these patients. Bone mass is improved and bone turnover normalized in patients who respond to antiviral therapy with interferon and ribavirin.

INTRODUCTION

Low bone mineral density (BMD) has been described in patients with chronic hepatitis C (HCV). The study objective was to evaluate the effect of antiviral therapy on BMD and bone metabolism in non-cirrhotic HCV patients with sustained virological response.

METHODS

We conducted a prospective study in 36 consecutive outpatients from the general community with non-cirrhotic HCV and an early and sustained virological response to peginterferon-alfa and ribavirin therapy. Determinations of BMD (dual X-ray absorptiometry at lumbar spine and femoral neck) and biochemical measurements of bone metabolism and sTNFR-55 were made at baseline, after 24 and 48 weeks of antiviral therapy, and at 48 weeks after the end of treatment.

RESULTS

Patients had a significantly reduced BMD, which significantly increased during the follow-up. Serum levels of sTNFR-55 and bone turnover markers were increased at baseline and significantly reduced at all subsequent time points. We found an inverse correlation between BMD and both serum aminotransferase levels and urine deoxypyridinoline (D-pyr) and a positive correlation between serum aminotransferases and both urine D-Pyr and serum sTNFR-55.

CONCLUSIONS

Patients with chronic hepatitis C have low bone mass associated with increased bone resorption, and some relationship can be expected between serum aminotransferase levels and the degree of bone mass loss. Bone mass may be improved and bone turnover normalized in patients who respond to antiviral therapy. Elevated serum sTRFR-55 levels may play a role in the bone mass loss of these patients.

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

Osteoporosis is increasingly reported in the aging HIV-positive population, and co-infection with hepatitis C virus (HCV) may further increase the risk of osteoporosis. However, it remains unclear whether HCV-related increased fracture risk is a function of the severity of liver disease. We calculated the time-updated alanine aminotransferase to platelet ratio index (APRI) score (an indirect marker of hepatic fibrosis) in all HIV-infected patients enrolled in the Veterans Affairs' Clinical Case Registry between 1984 and 2009. The association between HCV co-infection and incident osteoporotic fracture (defined as closed wrist, vertebral, or hip fracture) was assessed in univariate and multivariate Cox survival models adjusting for traditional risk factors for osteoporosis and APRI score or the presence of cirrhosis. A total of 772 osteoporotic fractures were identified among 56,660 HIV-infected patients (98.1% male; 31.3% HCV co-infected; median age 44.0 years) contributing 305,237 patient-years of follow-up. Fracture rates were significantly higher among HIV/HCV patients than HIV-only patients (2.57 versus 2.07/1000 patient-years, relative risk = 1.24, p < 0.0001). In a Cox multivariable model including age, race, smoking, drug use, body mass index, and antiretroviral therapy, HCV co-infection remained an independent predictor of osteoporotic fractures after controlling for presence of cirrhosis (hazard ratio [HR] = 1.32; p <0.001) or APRI score (HR = 1.30; p = 0.003). Among HIV/HCV co-infected patients, cirrhosis strongly predicted osteoporotic fractures (HR = 1.65; 95% confidence interval [CI] 1.11-2.44; p = 0.012), but APRI score was a weaker predictor (HR = 1.008; 95% CI 1.002-1.014; p = 0.015). In conclusion, among HIV-infected patients, severity of liver disease partly explains the HCV-associated increased risk of osteoporotic fractures. Other determinants of this increased risk remain to be defined.

In HIV/hepatitis C virus co-infected patients, higher 25-hydroxyvitamin D concentrations were not related to hepatitis C virus treatment responses but were associated with ritonavir use

BACKGROUND

Among patients with hepatitis C virus (HCV) monoinfection, 25-hydroxyvitamin D [25(OH)D] concentrations are positively associated with a response to peg-interferon/ribavirin. Data on the relation between 25(OH)D concentrations and HCV treatment response in HIV-infected patients are limited.

OBJECTIVE

The objective was to determine whether baseline 25(OH)D concentrations predict virologic response in HIV/HCV co-infected patients and to examine variables associated with 25(OH)D concentrations ≥30 ng/mL.

DESIGN

Data and samples from 144 HCV genotype 1, treatment-naive patients from a completed HCV treatment trial were examined in this retrospective study. Early virologic response (EVR) was defined as ≥2 log10 reduction in HCV RNA and/or HCV RNA <600 IU/mL at week 12 of peg-interferon/ribavirin treatment. Baseline 25(OH)D was measured by liquid chromatography/tandem mass spectrometry.

RESULTS

Compared with the non-EVR control group (n = 68), the EVR group (n = 76) was younger, had fewer cirrhotic subjects, had a higher proportion with the IL28B CC genotype, had a higher albumin concentration, and had a lower HCV viral load at baseline (P ≤ 0.05). The difference in baseline 25(OH)D concentrations between EVR and non-EVR patients was not statistically significant (median: 25 ng/mL compared with 20 ng/mL; P = 0.23). Similar results were found for sustained virologic response (SVR). In multivariable analysis, white and Hispanic race-ethnicity (OR: 6.26; 95% CI: 2.47, 15.88; P = 0.0001) and ritonavir use (OR: 2.68; 95% CI: 1.08, 6.65; P = 0.033) were associated with higher 25(OH)D concentrations (≥30 ng/mL).

CONCLUSION

Baseline 25(OH)D concentrations did not predict EVR or SVR. Because ritonavir impairs the conversion of 25(OH)D to the active metabolite, utilization of 25(OH)D may have been impaired in subjects taking ritonavir. This trial was registered at www.clinicaltrials.gov as NCT00078403.

Impact of hepatitis C virus infection on bone mineral density in renal transplant recipients

BACKGROUND

The average prevalence of hepatitis C virus (HCV) infection in renal transplant recipients is 10%. Studies of these patients with HCV infection usually focuses on long-term graft survival and patient survival. Studies of the correlation between HCV infection and bone mineral density (BMD) in renal transplant patients are limited. The aim of this study was to investigate whether HCV infection is a risk factor for BMD change during a short follow-up period.

METHODS

Seventy-six renal transplant recipients underwent 2 separate dual-energy X-ray absorptiometry (DXA) scans during a mean period of 14 months. Fifteen patients were HCV infection. First bone mineral density (BMD) at the lumbar spine, hip, and femoral neck was determined using dual-energy X-ray absorptiometry (DXA) between September 2008 and March 2009. After that, 34 patients took alendronate sodium 70 mg per week. Subgroups risk factors analysis was also performed into with or without alendronate. Immunosuppressive agents, bisphosphonates, patient characteristics, and biochemical factors were analyzed to identify associations with BMD.

RESULTS

After 14 months, in 76 patients, BMD of the lumbar spine had significantly increased (from 0.9 g/cm² to 0.92 g/cm², p<0.001), whereas BMD of the hip and femoral neck had not. Multiple linear regression analysis showed that HCV infection was negatively associated with BMD change in the lumbar spine ( β: -0.247, 95% CI, -0.035 to -0.002; p = 0.028). Moreover, in subgroup analysis, among 42 patients without alendronate, multiple linear regression analysis showed HCV infection was a risk factor for adverse BMD change of the lumbar spine ( β: -0.371, 95% CI, -0.043 to -0.003; p = 0.023).

CONCLUSION

HCV infection in renal transplant recipients was a negative risk factor for BMD change in the lumbar spine. Moreover, alendronate may be able to reverse the negative effect of HCV infection on bone in renal transplant recipients.

Association between chronic hepatitis C virus infection and bone mineral density

Whether chronic hepatitis C virus (HCV) infection is a risk factor for the development of bone disease has long been controversial. For this reason, chronic HCV-infected participants (n = 69) were recruited into a prospective cohort study and underwent dual-energy X-ray absorptiometry for determination of bone mineral density (BMD). Fibrosis staging was evaluated according to the noninvasive index FIB-4. T scores at the femoral neck and lumbar spine were used as the primary outcome variables to assess the association between degree of liver disease and BMD. The study cohort was 41 % male with a mean age of 53.6 years. The mean BMD, Z score, and T score values of lumbar spine in chronic hepatitis C (CHC) patients were significantly lower than those in healthy controls (p < 0.001). The rate of osteoporosis for CHC patients aged 45-54 years was significantly higher than that of the control group (p = 0.011). Bone alkaline phosphatase and C-terminal cross-linking telopeptide of type I collagen levels were also significantly higher in CHC patients with reduced BMD. Patients with more advanced liver fibrosis had significantly lower BMD. In conclusion, reduced BMD is common in this population of chronic HCV-infected patients and associated with liver disease severity. This extrahepatic manifestation is probably secondary to increased bone turnover in osteodystrophy pathogenesis.

Vitamin D deficiency and its relation to bone mineral density and liver fibrosis in HIV-HCV coinfection

BACKGROUND

Fractures and cirrhosis are major causes of morbidity and mortality among HIV-HCV-coinfected individuals. It is not known whether vitamin D deficiency is associated with these outcomes.

METHODS

Between 2005 and 2007, 116 HIV-HCV-coinfected individuals underwent dual-energy X-ray absorptiometry within 1 year of a liver biopsy. 25-Hydroxyvitamin D (25OHD) and parathyroid hormone were measured from archived samples. Low bone mineral density (BMD) was defined as BMD≥2 standard deviations lower than age-, sex- and race-matched controls (Z-score ≤-2.0) at the total hip, femoral neck or lumbar spine. Histological fibrosis staging was assessed according to the METAVIR system (0 [no fibrosis] to 4 [cirrhosis]).

RESULTS

The cohort was 87% African-American and 63% male. The median age (IQR) was 49.9 years (46.5-53.3). A total of 89% had a CD4(+) T-cell count >200 cells/mm(3) and 64% were receiving HAART. The median 25OHD was 19 ng/ml (IQR 11.0-26.0). Hypovitaminosis D (25OHD≤15 ng/ml) was present in 41% and secondary hyperparathyroidism, defined by parathyroid hormone >65 pg/ml, was present in 24%. In total, 27% had low BMD (Z-score ≤-2) at the spine, femoral neck or total hip, and 39% had significant hepatic fibrosis (METAVIR≥2). In multivariate analysis, vitamin D deficiency was not associated with significant fibrosis or with BMD at any site.

CONCLUSIONS

Vitamin D deficiency was highly prevalent in this mostly African-American HIV-HCV-coinfected population, but was not related to BMD or liver disease severity. These data suggest that efforts to increase vitamin D levels in this population may not improve bone or liver outcomes.

Hip bone geometry in HIV/HCV-co-infected men and healthy controls

People with both HIV and hepatitis C are more likely than those with HIV alone to have wrist, hip, and spine fractures. We compared hip strength between HIV/HCV-co-infected men and healthy men and found that HIV/HCV-co-infected men had decreased hip strength due to lower lean body mass.

INTRODUCTION

Hepatitis C co-infection is a risk factor for fragility fracture among HIV-infected populations. Whether bone strength is compromised in HIV/HCV-co-infected patients is unknown.

METHODS

We compared dual-energy x-ray absorptiometry (DXA)-derived hip geometry, a measure of bone strength, in 88 HIV/HCV-co-infected men from the Johns Hopkins HIV Clinic to 289 men of similar age and race and without HIV or HCV from the Boston Area Community Health Survey/Bone Survey. Hip geometry was assessed at the narrow neck, intertrochanter, and shaft using hip structural analysis. Lean body mass (LBM), total fat mass (FM), and fat mass ratio (FMR) were measured by whole-body DXA. Linear regression was used to identify body composition parameters that accounted for differences in bone strength between cohorts.

RESULTS

HIV/HCV-co-infected men had lower BMI, LBM, and FM and higher FMR compared to controls (all p < 0.05). At the narrow neck, significant differences were observed between HIV/HCV-co-infected men and controls in bone mineral density, cross-sectional area, section modulus, buckling ratio, and centroid position. After adjustment for race, age, smoking status, height, and weight, only buckling ratio and centroid position remained significantly different between cohorts (all p < 0.05). Substituting LBM, FM, and FMR for weight in the multivariate model revealed that differences in LBM, but not FM or FMR, accounted for differences in all narrow neck parameters between cohorts, except buckling ratio and centroid position.

CONCLUSION

HIV/HCV-co-infected men have compromised hip strength at the narrow neck compared to uninfected controls, which is attributable in large part to lower lean body mass.

Osteoporotic fracture risk associated with cumulative exposure to tenofovir and other antiretroviral agents

BACKGROUND

Whereas tenofovir (TDF) exposure has been associated with decreased bone density, it remains unclear whether it is associated with increased risk of osteoporotic fractures.

METHODS

Patients with any osteoporotic fracture (defined as wrist, vertebral or hip fracture) occurring after HIV diagnosis were identified by International Classification of Diseases - 9th Revision (ICD-9) code in the Veterans Affairs' Clinical Case Registry from 1988 to 2009. Osteoporotic fracture risk associated with cumulative exposure to TDF and other antiretrovirals was examined in univariate analysis and multivariate model 1 (MV1 - controlling for race, age, tobacco use, diabetes, body mass index, and hepatitis C status) and model 2 (MV2 - controlling for MV1 variables + concomitant antiretroviral exposures).

RESULTS

Among 56,660 patients evaluated, TDF exposure (total 46,062 person-years) was associated with an osteoporotic fracture hazard ratio of 1.080 [95% confidence interval (CI) 1.02-1.15, P < 0.001] in univariate analysis, 1.06 (0.99-1.12) in MV1 and 1.06 (0.99-1.14) in MV2. Among patients entering the cohort in the highly active antiretroviral therapy (HAART) era (n = 32,439), TDF exposure was associated with a yearly hazard ratio for osteoporotic fracture of 1.16 (95% CI 1.08-1.24, P < 0.001) in univariate model, 1.13 (1.05-1.21, P = 0.001) in MV1 and 1.12 (1.03-1.21, P = 0.011) in MV2. Boosted protease inhibitor exposure was associated with hazard ratio of 1.11 (1.05-1.18, P = 0.001) in univariate model, 1.08 (1.01-1.15, P = 0.026) in MV1 and 1.05 (0.97-1.13, P = 0.237) in MV2. Among protease inhibitors, lopinavir/ritonavir (LPV/RTV) had an osteoporotic fracture hazard ratio of 1.09 (CI 1.00-1.20, P = 0.051) in MV2.

CONCLUSION

Cumulative exposure to TDF and, among protease inhibitors, LPV/RTV was independently predictive of increased risk of osteoporotic fracture in the HAART era.

Classical and emerging roles of vitamin D in hepatitis C virus infection

According to the Institute of Medicine, the risk of clinically significant vitamin D deficiency increases at 25-hydroxyvitamin D levels below 20 ng/mL. By this standard, most cirrhotic hepatitis C virus- (HCV-) positive patients and many noncirrhotic patients are vitamin D-deficient. The high prevalence of vitamin D deficiency among HCV patients is a cause for concern for several specific reasons. Classic studies established the importance of vitamin D and calcium in maintaining bone. Vitamin D's beneficial effects on bone are likely to be vital for HCV-infected patients because these individuals have a high prevalence of low bone mineral density. Many pharmaceutical agents reduce bone density and exposure to these drugs may increase bone disease in HCV-positive patients. Bone loss occurs following liver transplantation and bone density is often low in patients with HIV/HCV co-infection who are on combination antiretroviral therapy. Some evidence suggests that ribavirin reduces bone density, underscoring the special need to monitor vitamin D in patients receiving HCV treatment and to prescribe supplements, as appropriate. In addition to its role in calcium metabolism, vitamin D is also an immune modulator that reduces inflammation while enhancing protective immune responses. Higher vitamin D levels are associated with less liver fibrosis and less inflammation in HCV patients. Recent studies show that low vitamin D levels are associated with treatment failure among HCV-infected patients receiving pegylated-interferon and ribavirin. If confirmed, these findings will provide an additional reason to ensure adequate levels of vitamin D. Information about how to monitor vitamin D status and how to use vitamin D supplements most effectively in HCV-infected patients is provided.