Fragility fractures and bone mineral density in HIV positive women: a case-control population-based study

Osteoporosis in Human Immunodeficiency Virus Patients - An Emerging Clinical Concern

The advent of highly active anti-retroviral therapy (HAART) has significantly improved the survival of human immunodeficiency virus (HIV)-infected patients transforming the HIV infection from a fatal illness into a manageable chronic disease. As the number of older HIV-infected individuals increases, several ageing-related co-morbidities including osteopenia/osteoporosis and fractures have emerged. Patients exposed to HIV infection and its treatment may develop fragility fractures with potential significant impact on quality of life and survival. However, the awareness of HIV-related skeletal fragility is still relatively low and most HIV-infected patients are not investigated for osteoporosis and treated with anti-osteoporotic drugs in daily clinical practice. This article reviews the literature data on osteoporosis and osteopenia in HIV infection, focusing on the pathophysiological, clinical and therapeutic aspects of fragility fractures.

Comparative risk of fracture in men and women with HIV

CONTEXT

Men and women with HIV have an increased risk of fracture compared with individuals without HIV; however, it is unknown if women with HIV fracture at higher rates than men.

OBJECTIVE

We aimed to compare the incidence rates (IR) of fractures between men and women with HIV.

DESIGN

The study was designed as a cohort study, examining medical records from November 2001 to August 2012.

SETTING

The study was performed using records from two tertiary-care hospitals in Boston, Massachusetts.

PATIENTS

The study patients were adults with HIV: this was defined by diagnosis codes for HIV on two visits, at least one prescription for antiretroviral therapy, and at least 18 years of age.

INTERVENTION

IRs per 1000 person-years of all fractures and fractures at osteoporotic sites were calculated. We calculated IRs within age and gender strata and estimated IR ratios (IRR) between men and women.

MAIN OUTCOME MEASURE

The main outcome measure was fracture at any site.

RESULTS

We identified a cohort of 3161 HIV-infected patients (869 women and 2292 men) with a total of 587 fractures. The IRR of all fractures was 1.00 (95% confidence interval [CI] 0.83-1.19) between men and women. The IR of fractures at osteoporotic sites among men was 15.2 (95% CI 12.7-17.6) per 1000 person-years compared with 12.1 (95% CI 8.6-15.6) in women, with IRR of 1.26 (95% CI 0.90-1.75). Men had similar or higher IRs than women for osteoporotic site fractures across most age groups.

CONCLUSIONS

This study found similar rates of fracture in men and women with HIV. Further studies validating these findings are required to determine whether men with HIV should be screened for osteoporosis.

Elevated suppressor of cytokine signaling-1 (SOCS-1): a mechanism for dysregulated osteoclastogenesis in HIV transgenic rats

Accelerated bone loss leading to osteopenia, osteoporosis, and bone fracture is a major health problem that is increasingly common in human immunodeficiency virus (HIV)-infected patients. The underlying pathogenesis is unclear but occurs in both treatment naïve and individuals receiving antiretroviral therapies. We developed an HIV-1 transgenic rat that exhibits many key features of HIV disease including HIV-1-induced changes in bone mineral density (BMD). A key determinant in the rate of bone loss is the differentiation of osteoclasts, the cells responsible for bone resorption. We found HIV-1 transgenic osteoclast precursors (OCP) express higher levels of suppressor of cytokine signaling-1 (SOCS-1) and TNF receptor-associated factor 6 (TRAF6) and are resistant to interferon-gamma (IFN-γ) mediated suppression of osteoclast differentiation. Our data suggest that dysregulated SOCS-1 expression by HIV-1 transgenic OCP promotes osteoclastogenesis leading to the accelerated bone loss observed in this animal model. We propose that elevated SOCS-1 expression in OCP antagonizes the inhibitory effects of IFN-γ and enhances receptor activator of NF-kB ligand (RANKL) signaling that drives osteoclast differentiation and activation. Understanding the molecular mechanisms of HIV-associated BMD changes has the potential to detect and treat bone metabolism disturbances early and improve the quality of life in patients.

HIV and ageing: what the geriatrician needs to know

The transformation of human immunodeficiency virus (HIV) from a rapidly fatal disease to a chronic manageable illness has resulted in annual increases in the numbers of people living with HIV. The HIV cohort is therefore ageing, with numbers of older adults with HIV climbing, through both prolonged survival and late acquisition of the disease. Associated with ageing is an accumulation of HIV-associated non-AIDS related co-morbidities, creating a complex patient group affected by multi-morbidity along with polypharmacy, functional decline and complex social issues. With this in mind, this review seeks to explore areas where HIV (diagnosed or undetected) may impact on the work of clinical geriatricians.

Prevalence of and risk factors for osteoporosis and fracture among a male HIV-infected population in the UK

Rates of osteoporosis and fracture may be increased in HIV but there are few UK data. Our aim was to examine the prevalence of and risk factors for osteoporosis and fractures among a homogeneous cohort of well-characterized HIV-infected men. In total, 168 men were recruited, median age 45 years, 37 combination antiretroviral therapy (cART) naïve, 46 with <3 years cART exposure and 85 cART-exposed longer term (median >10 years). All participants provided information on bone health and underwent DEXA scanning. Osteopenia was found in 58% of subjects and osteoporosis in 12%; 14% reported fractures since HIV diagnosis. Number of fractures since HIV diagnosis was significantly increased among those with osteoporosis (OR 3.5, 95% CI 1.2-10.4, p = 0.018). Duration of infection greater than 13 years was significantly associated with osteoporosis. Duration of cART was associated in univariate but not multivariate analyses. Strategies to prevent osteoporosis and fractures in HIV will require attention to viral and lifestyle factors and not just cART.

Trabecular and cortical microarchitecture in postmenopausal HIV-infected women

Our objective was to assess the effects of HIV infection and antiretroviral therapy on trabecular and cortical microarchitecture in postmenopausal minority women. A subgroup of 106 (46 HIV-infected, 60 uninfected) postmenopausal Hispanic and African American women from an established cohort had areal bone mineral density (aBMD) measured by dual-energy X-ray absorptiometry and trabecular and cortical volumetric BMD (vBMD) and microarchitecture measured by high-resolution peripheral quantitative computed tomography (HRpQCT) at the radius and tibia. HIV-infected women were slightly younger (58 ± 1 vs. 61 ± 1 years, p = 0.08), and had lower body mass index (BMI; 28 ± 1 vs. 32 ± 1 kg/m(2), p < 0.01). BMI-adjusted aBMD Z scores were lower in HIV-infected women at the lumbar spine, total hip, and ultradistal radius. Serum N-telopeptide and C-telopeptide levels were also higher in HIV-infected women. Trabecular and cortical vBMD were similar at the radius, but cortical area (105.5 ± 2.4 vs. 120.6 ± 2.0 mm(2), p < 0.01) and thickness (956 ± 33 vs. 1,075 ± 28 μm, p < 0.01) at the tibia were approximately 11-12 % lower in HIV-infected women. Differences remained significant after adjusting for age, BMI, and race/ethnicity. In contrast, cortical porosity was similar in the two groups. Although HIV-infected postmenopausal women had lower aBMD at the spine, total hip, and ultradistal radius and higher levels of bone resorption markers, the only differences detected by HRpQCT were lower cortical thickness and area at the tibia.

HIV infection is strongly associated with hip fracture risk, independently of age, gender, and comorbidities: a population-based cohort study

HIV infection and antiretroviral therapies have detrimental effects on bone metabolism, but data on their impact on fracture risk are controversial. We conducted a population-based cohort study to explore the association between clinical diagnosis of HIV infection and hip and major osteoporotic fracture risk. Data were obtained from the SIDIAP(Q) database, which contains clinical information for >2 million patients in Catalonia, Spain (30% of the population). We screened the database to identify participants with a clinical diagnosis of HIV infection, and ascertained incident hip and osteoporotic major fractures in the population aged 40 years or older in 2007 to 2009. In addition, data on incident fractures involving hospital admission were obtained from the Hospital Admissions database. Cox regression models were used to estimate hazard ratios (HRs) for the HIV-infected versus uninfected participants. Models were adjusted for age, sex, body mass index, smoking status, alcohol drinking, oral glucocorticoid use, and comorbid conditions (Charlson index). Among 1,118,156 eligible participants, we identified 2489 (0.22%) subjects with a diagnosis of HIV/AIDS. Age- and sex-adjusted HR for HIV/AIDS were 6.2 (95% confidence interval [CI] 3.5-10.9; p < 0.001) and 2.7 (2.01-3.5; p < 0.001) for hip and major fractures, respectively; this remained significant after adjustment for all mentioned potential confounders: HR 4.7 (2.4-9.5; p < 0.001) and 1.8 (1.2-2.5; p = 0.002). After stratifying by age, the association between HIV infection and major fractures was attenuated for those aged <59 years (adjusted HR 1.35 [0.88-2.07], p = 0.17) but appeared stronger in older patients (adjusted HR 2.11 [1.05-4.22], p = 0.035). We report a strong association between HIV infection and hip fracture incidence, with an almost fivefold increased risk in the HIV infected, independent of sex, age, smoking, alcohol drinking, and comorbidities. Similarly, we demonstrate a 75% higher risk of all clinical fractures and a 60% increase in risk of non-hip clinical fractures among patients with a diagnosis of HIV infection.

The Role of Inflammatory Cytokines, the RANKL/OPG Axis, and the Immunoskeletal Interface in Physiological Bone Turnover and Osteoporosis

Although it has long been recognized that inflammation, a consequence of immune-driven processes, significantly impacts bone turnover, the degree of centralization of skeletal and immune functions has begun to be dissected only recently. It is now recognized that formation of osteoclasts, the bone resorbing cells of the body, is centered on the key osteoclastogenic cytokine, receptor activator of NF- κ B ligand (RANKL). Although numerous inflammatory cytokines are now recognized to promote osteoclast formation and skeletal degradation, with just a few exceptions, RANKL is now considered to be the final downstream effector cytokine that drives osteoclastogenesis and regulates osteoclastic bone resorption. The biological activity of RANKL is moderated by its physiological decoy receptor, osteoprotegerin (OPG). New discoveries concerning the sources and regulation of RANKL and OPG in physiological bone turnover as well as under pathological (osteoporotic) conditions continue to be made, opening a window to the complex regulatory processes that control skeletal integrity and the depth of integration of the skeleton within the immune response. This paper will examine the interconnection between bone turnover and the immune system and the implications thereof for physiological and pathological bone turnover.

Bone mineral density in children and adolescents with perinatal HIV infection

OBJECTIVE

To estimate prevalence of low bone mineral density (BMD) in perinatally HIV-infected (HIV+) and HIV-exposed but uninfected (HEU) children, and to determine predictors of BMD in HIV+.

DESIGN

Cross-sectional analysis within a 15-site United States and Puerto Rico cohort study.

METHODS

Total body and lumbar spine BMD were measured using dual energy-X-ray absorptiometry. BMD Z-scores accounted for bone age and sex. Multiple linear regression was used to evaluate differences in Z-scores by HIV status and for predictors of BMD in HIV+.

RESULTS

350 HIV+ and 160 HEU were enrolled. Mean age was 12.6 and 10.7 years for HIV+ and HEU, respectively. Most (87%) HIV+ were receiving HAART. More HIV+ than HEU had total body and lumbar spine Z-scores less than -2.0 (total body: 7 vs. 1%, P = 0.008; lumbar spine: 4 vs. 1%, P = 0.08). Average differences in Z-scores between HIV+ and HEU were attenuated after height and/or weight adjustment. Among HIV+, total body Z-scores were lower in those with higher CD4% and in those who ever used boosted protease inhibitors or lamivudine. Lumbar spine Z-scores were lower with higher peak viral load and CD4%, more years on HAART, and ever use of indinavir.

CONCLUSION

Rates of low BMD in HIV+ children were greater than expected based on normal population distributions. These differences were partially explained by delays in growth. As most HIV+ children in this study had not entered their pubertal growth spurt, prepubertal factors associated with BMD, magnified or carried forward, may result in sub-optimal peak BMD in adulthood.

Effect of alendronate on HIV-associated osteoporosis: a randomized, double-blind, placebo-controlled, 96-week trial (ANRS 120)

Low bone mineral density (BMD) is common in HIV-infected patients. Bisphosphonates such as alendronate potently inhibit bone resorption and are effective against osteoporosis. The aim of the ANRS 120 Fosivir trial was to evaluate the effect of alendronate on low BMD in HIV-infected patients. HIV-1-infected adults with a t-score≤-2.5 at the lumbar spine and/or total hip, as assessed by dual x-ray absorptiometry, and no other known risk factors for low BMD, were randomized to receive either extended-release alendronate 70 mg weekly or placebo for 96 weeks, with stratification for gender. All the patients also received daily calcium carbonate (500 mg) and vitamin D (400 U). The primary endpoint for efficacy was the percentage change in BMD at the site with a t-score≤-2.5. Forty-four antiretroviral-treated patients (42 men, 2 women) were enrolled. The median age was 45 years, the median CD4 cell count was 422/mm(3), and viral load was <400 copies/ml in 84% of patients. Baseline characteristics were well balanced between the alendronate (n=20) and placebo (n=24) groups. At baseline, 15 patients (75%) in the alendronate group and 17 patients (71%) in the placebo group had a t-score≤-2.5 at the lumbar spine. In the main analysis, BMD at the site with a t-score≤-2.5 increased by 7.1% and 1.0%, respectively, in the alendronate (n=14) and placebo (n=20) groups at week 96 [mean difference, 6.1% (95% CI 2.8 to 9.3); p=0.0003]. Alendronate 70 mg weekly for 96 weeks improves BMD in HIV-1-infected patients on antiretroviral therapy.

HIV-associated osteoporosis in Ireland: prevalence and risk factors

Effective antiretroviral therapy has transformed HIV infection into a chronic disease. The emphasis is now on the management of the consequences of life-long treatment and associated toxicities, including osteoporosis and fragility fractures. There is a paucity of data on HIV-associated osteoporosis in Ireland. Aims: The study aims to investigate the prevalence and relevant risk factors for HIV-associated osteoporosis. Methods: A cross-sectional study of 146 HIV-positive patients from two different tertiary referral hospitals in Dublin was employed. Results: The prevalence of osteopenia and osteoporosis of the hip and/or lumbar spine was 53.4 and 9.6%, respectively. We found significant association between decreased hip bone mineral density (BMD) and increasing age, male gender, cigarette smoking, ethnicity, intravenous drug use and lower nadir CD4. A low BMI was the single most important independent predictor of reduced BMD in our study cohort. Conclusion: Low BMD affects a large proportion of HIV-positive patients in Ireland. Our results suggest that BMD screening, monitoring and treatment (if indicated) should be considered in all HIV-positive patients.

HIV: inflammation and bone

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

Effects of vitamin D deficiency and combination antiretroviral therapy on bone in HIV-positive patients

OBJECTIVES

In the era of combination antiretroviral therapy (cART), vitamin D deficiency, low bone mineral density (BMD) and fractures have emerged as subjects of concern in HIV-positive patients. Testing for vitamin D deficiency has been widely adopted in clinical practice even though the benefits of vitamin D supplementation in this population remain uncertain. The objective of this review was to evaluate the evidence for such a strategy.

DESIGN

Systematic review of the literature on vitamin D deficiency in HIV infection, the effects of cART on vitamin D status, and the effects of vitamin D deficiency and cART on parathyroid hormone (PTH), bone turnover, BMD and the incidence of fractures in HIV-positive patients.

METHODS

PubMed was used to identify relevant articles up to September 2011.

RESULTS

Vitamin D deficiency, secondary hyperparathyroidism and low BMD are common in HIV-positive patients. Efavirenz is associated with a reduction in 25-hydroxy vitamin D levels, tenofovir with secondary hyperparathyroidism, and cART with increased bone turnover and low BMD. The clinical significance of low BMD, however, remains unclear, especially in younger patients. Although the incidence of fractures may be increased in HIV-positive patients, the contribution of low BMD and vitamin D deficiency to these fractures is uncertain. Limited data on vitamin D supplementation in HIV-positive patients have shown transient, beneficial effects on PTH, but no effects on BMD.

CONCLUSION

The benefits of vitamin D supplementation in this population need to be demonstrated before widespread 'test and treat' policies can be recommended as part of routine clinical practice.

Low CD4 count is associated with an increased risk of fragility fracture in HIV-infected patients

BACKGROUND

Low bone mineral density in HIV-infected patients is an increasingly recognized clinical problem. The aim of this study was to determine the incidence, prevalence, and risk factors for development of low trauma or fragility fractures in an HIV-infected population.

METHODS

A 1:2 matched case-control study was performed of HIV-infected patients attending the Alfred Hospital between 1998 and 2009. Controls were matched on gender, age, and duration of HIV infection.

RESULTS

The overall fracture incidence rate was 0.53 per 100 person-years [95% confidence interval (CI): 0.43 to 0.65] and period prevalence of 3.34 per 100 patients (95% CI: 2.66 to 4.13). There were 73 low trauma fractures in 61 patients. Patients were predominantly male (89%) with a mean age of 49.8 years. Independent risk factors for fragility fracture were a CD4 cell count <200 cells per microliter odds ratio (OR): 4.91 (95% CI: 1.78 to 13.57, P = 0.002), corticosteroids OR: 8.96 (95% CI: 1.55 to 51.88, P = 0.014) and anti-epileptic medications OR: 8.88 (95% CI: 1.75 to 44.97, P = 0.008). There were no significant associations between HIV viremia (P = 0.18), use of or class of antiretroviral medication, and risk of fracture. Eighty-eight percent of patients with fracture had established osteopenia or osteoporosis.

CONCLUSION

This is the largest clinical study to date of fragility fractures occurring in an HIV-infected population. The study found that risk of fracture was strongly associated with a low CD4 cell count, use of corticosteroids, and anti-epileptic medications. There were no associations between fracture risk and viral load, use of class, or duration of antiretroviral agent.

Prevention of bone loss and management of fracture risk in HIV-infected individuals: case studies and recommendations for different patient subgroups

Increased life-expectancy and the need for long-term antiretroviral therapy have brought new challenges to the clinical management of HIV-infected individuals. While the prevalence of osteoporosis and fractures is probably increased in HIV-infected patients, optimal strategies for risk assessment and treatment in this relatively young population are yet to be defined. Prevention of bone loss is likely to become an important component of HIV care as the HIV-infected patient population grows older. In this article, we present an overview of the literature on bone loss in individuals with HIV and discuss the practical application of the European AIDS Clinical Society (EACS) guidelines to a range of clinical case scenarios.

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.

Increased risk of fragility fractures among HIV infected compared to uninfected male veterans

Background

HIV infection has been associated with an increased risk of fragility fracture. We explored whether or not this increased risk persisted in HIV infected and uninfected men when controlling for traditional fragility fracture risk factors.

Methodology/Principal Findings

Cox regression models were used to assess the association of HIV infection with the risk for incident hip, vertebral, or upper arm fracture in male Veterans enrolled in the Veterans Aging Cohort Study Virtual Cohort (VACS-VC). We calculated adjusted hazard ratios comparing HIV status and controlling for demographics and other established risk factors. The sample consisted of 119,318 men, 33% of whom were HIV infected (34% aged 50 years or older at baseline, and 55% black or Hispanic). Median body mass index (BMI) was lower in HIV infected compared with uninfected men (25 vs. 28 kg/m²; p<0.0001). Unadjusted risk for fracture was higher among HIV infected compared with uninfected men [HR: 1.32 (95% CI: 1.20, 1.47)]. After adjusting for demographics, comorbid disease, smoking and alcohol abuse, HIV infection remained associated with an increased fracture risk [HR: 1.24 (95% CI: 1.11, 1.39)]. However, adjusting for BMI attenuated this association [HR: 1.10 (95% CI: 0.97, 1.25)]. The only HIV-specific factor associated with fragility fracture was current protease inhibitor use [HR: 1.41 (95% CI: 1.16, 1.70)].

Conclusions/Significance

HIV infection is associated with fragility fracture risk. This risk is attenuated by BMI.

Vitamin D deficiency in HIV-infected postmenopausal Hispanic and African-American women

We evaluated vitamin D status in HIV+ and HIV- postmenopausal African-American (AA) and Hispanic women. Most women (74-78%) had insufficient 25-hydroxyvitamin D (25OHD) levels, regardless of HIV status. 25OHD was lower in AA women and women lacking supplement use, providing support for screening and supplementation. Among HIV+ women, 25OHD was associated with current CD4 but not type of antiretroviral therapy.

INTRODUCTION

To evaluate vitamin D status and factors associated with vitamin D deficiency and insufficiency in HIV-infected (HIV+) postmenopausal minority women.

METHODS

In this cross-sectional study, 89 HIV+ and 95 HIV- postmenopausal women (33% AA and 67% Hispanic) underwent assessment of 25OHD, 1,25-dihydroxyvitamin D, parathyroid hormone, markers of bone turnover and bone mineral density by dual energy X-ray absorptiometry.

RESULTS

The prevalence of low 25OHD did not differ by HIV status; the majority of both HIV+ and HIV- women (74-78%) had insufficient levels (<30 ng/ml). Regardless of HIV status, 25OHD was significantly lower in AA subjects, and higher in subjects who used both calcium and multivitamins. In HIV+ women on antiretroviral therapy (ART), 25OHD was directly associated with current CD4 count (r=0.32; p<0.01) independent of age, ethnicity, BMI, or history of AIDS-defining illness. No association was observed between 1,25(OH)(2)D and CD4 count or between serum 25OHD, 1,25(OH)(2)D or PTH and type of ART.

CONCLUSIONS

In postmenopausal minority women, vitamin D deficiency was highly prevalent and associated with AA race and lack of supplement use, as well as lower current CD4 cell count. These results provide support for screening and repletion of vitamin D in HIV+ patients.

Hypovitaminosis D and bone mineral density in human immunodeficiency virus-infected men from India, with or without antiretroviral therapy

OBJECTIVE

To study the vitamin D status and bone mineral density (BMD) in men infected with human immunodeficiency virus (HIV) in a tertiary care center from southern India.

METHODS

We conducted a cross-sectional study of 35 HIV-infected men (between 20 and 50 years old) receiving highly active antiretroviral therapy (HAART) (group 1) in comparison with 35 age- and body mass index-matched HIV-positive antiretroviral therapy-naïve men (group 2) and 35 HIV-negative healthy control subjects (group 3).

RESULTS

A significantly greater proportion (P = .002) of patients (74%) in the HAART group had vitamin D deficiency (<20 ng/mL) in comparison with the other 2 groups (37% in each group). The mean intact parathyroid hormone level was higher (P<.001) and the mean duration of exposure to sunlight was lower (P = .001) in the HAART group than in the other 2 groups. By logistic regression analysis, HAART was found to be significantly associated with vitamin D deficiency. The BMD in the femoral neck was significantly lower in men with HIV infection who were receiving HAART in comparison with the other 2 groups (P = .006). On multivariate logistic regression, older age, low body mass index, and high parathyroid hormone levels emerged as factors significantly associated with decreased BMD at the femoral neck.

CONCLUSION

A significant proportion of patients receiving HAART had vitamin D deficiency. The secondary hyperparathyroidism probably due to vitamin D deficiency is an important contributing factor for the observed changes in BMD. Vitamin D deficiency noted in this group is probably multifactorial, and further research is needed to determine whether the effect of HAART on vitamin D metabolism is an additional causative factor and what benefit vitamin D supplementation might confer in these patients.

HIV and bone loss

The use of antiretroviral therapy has significantly reduced the number of deaths due to HIV/AIDS. However, no current therapy can suppress the virus completely, and as the HIV-infected population continues to live longer new complications are emerging from the persistence of the virus and use of antiretroviral therapy. This review summarizes the clinical evidence linking HIV-associated osteoporosis to direct infection and antiretroviral therapy (ART) use. The purported molecular mechanisms involved in bone loss are also reviewed. Additionally, recommendations regarding the pharmacologic management of HIV/ART-related osteoporosis are given.

Fracture incidence in HIV-infected women: results from the Women's Interagency HIV Study

BACKGROUND

The clinical importance of the association of HIV infection and antiretroviral therapy (ART) with low bone mineral density (BMD) in premenopausal women is uncertain because BMD stabilizes on established ART and fracture data are limited.

METHODS

We measured time to first new fracture at any site with median follow-up of 5.4 years in 2391 (1728 HIV-infected, 663 HIV-uninfected) participants in the Women's Interagency HIV Study (WIHS). Self-report of fracture was recorded at semiannual visits. Proportional hazard models assessed predictors of incident fracture.

RESULTS

At baseline, HIV-infected women were older (40 ± 9 vs. 36 ± 10 years, P < 0.0001), more likely to report postmenopausal status and be hepatitis C virus-infected, and weighed less than HIV-uninfected women. Among HIV-infected women, mean CD4(+) cell count was 482 cells/μl; 66% were taking ART. Unadjusted incidence of fracture did not differ between HIV-infected and uninfected women (1.8 vs. 1.4/100 person-years, respectively, P = 0.18). In multivariate models, white (vs. African-American) race, hepatitis C virus infection, and higher serum creatinine, but not HIV serostatus, were statistically significant predictors of incident fracture. Among HIV-infected women, older age, white race, current cigarette use, and history of AIDS-defining illness were associated with incidence of new fracture.

CONCLUSION

Among predominantly premenopausal women, there was little difference in fracture incidence rates by HIV status, rather traditional risk factors were important predictors. Further research is necessary to characterize fracture risk in HIV-infected women during and after the menopausal transition.

Bone changes and fracture risk in individuals infected with HIV

The life expectancy of individuals infected with HIV has improved greatly since the institution of combination antiretroviral therapy. However, many metabolic derangements have been discovered with long-term combination antiretroviral treatment, including lipodystrophy; insulin resistance; and, more recently, abnormal bone metabolism. It is well-documented that bone mineral density (BMD) in HIV-positive patients is lower compared with the expected BMD in non-HIV-positive patients. The underlying cause of lower BMD is unknown but is thought to be a multifactorial process. Conflicting evidence exists regarding the effect of antiretroviral exposure and duration of treatment, antiretroviral type, and cumulative HIV viral exposure on bone health. Here we review the bone changes that occur with HIV infection and treatment.

HIV and bone mineral density

PURPOSE OF REVIEW

This review details the clinical aspects and pathogenesis of low bone mineral density (BMD) in HIV, discusses broad management issues and outlines areas in which our understanding of this condition is incomplete.

RECENT FINDINGS

Low BMD is prevalent in HIV-infected patients, with traditional risk factors, HIV infection and exposure to antiretroviral therapy all contributing. The role of specific antiretrovirals in the development of low BMD remains controversial, but most changes arise at either antiretroviral therapy initiation or switch.

SUMMARY

Further research is needed to clarify mechanisms underlying low BMD in HIV, whether low BMD will translate to increased fractures and to determine the correct therapeutic approach to low BMD in HIV, particularly in younger HIV-infected patients.

Bone loss in patients with HIV infection

The prognosis of HIV infection has been considerably improved by the introduction of antiretroviral drugs. However, the longer survival times are associated with the emergence of new complications including decreased bone mineral density (BMD) values and/or bone insufficiency fractures. A meta-analysis of studies published between 1966 and 2005 showed bone absorptiometry results indicating osteoporosis in 15% of HIV patients and osteopenia in 52%. Longitudinal studies found no evidence that antiretroviral drug therapy contributed to the occurrence of bone loss. Available data indicate uncoupling with increases in bone resorption markers and decreases in bone formation markers. In addition to conventional risk factors for osteoporotic fractures, factors in HIV-infected patients may include malnutrition (wasting syndrome), hypogonadism, disorders in calcium and phosphate metabolism, and HIV infection per se. In patients with established bone insufficiency, bisphosphonate therapy should be considered. Alendronate in combination with vitamin D and calcium supplementation has been found effective in improving BMD values.

Short-term bone loss in HIV-infected premenopausal women

BACKGROUND

Low bone mineral density (BMD) has been reported in HIV+ women, but less is known about the longitudinal evolution of BMD and fracture incidence.

METHODS

In 100 HIV+ and 68 HIV- premenopausal women in the Women's Interagency HIV Study, BMD was measured by dual energy x-ray absorptiometry at the femoral neck (FN) and lumbar spine (LS) at index visit and after a median of 2.5 years.

RESULTS

In HIV+ women, BMD at index visit was normal but 5% lower at the LS and FN than in HIV- women. Annual percent decrease in BMD did not differ between HIV+ and HIV- women at the LS (-0.8% +/- 0.2% vs -0.4% +/- 0.2%, P = 0.20) or FN (-0.8% +/- 0.3% vs -0.6% +/- 0.3%, P = 0.56) and remained similar after adjustment for age, weight, and BMD at index visit. Among HIV+ women, bone loss was associated with vitamin D deficiency and opiate use but not with use or class of antiretrovirals. Incidence of self-reported fracture was 0.74 per 100 person-years in HIV+ women and similar in HIV- women.

CONCLUSIONS

In premenopausal HIV+ women, index BMD was lower than comparable HIV- women; however, rates of bone loss at the LS and FN were similar over 2.5 years of observation, irrespective of antiretroviral therapy.

Bone mineral densities in individuals with Gilbert's syndrome: a cross-sectional, case-control pilot study

BACKGROUND

Unconjugated bilirubin inhibits osteoblastic proliferative activity in vitro, raising the possibility that Gilbert's syndrome (GS) patients are at increased risk of osteoporosis.

OBJECTIVES

To compare bone mineral density (BMD), serum parathyroid hormone (PTH), C-telopeptide (CTX) and osteocalcin levels in GS subjects versus matched controls in a cross-sectional, case-control study.

METHODS

BMD determinations were obtained with central dual energy x-ray absorptiometry. Serum PTH, CTX and osteocalcin levels were measured by enzyme immunoassay.

RESULTS

A total of 17 GS and 30 control subjects were studied. Overall, there were no significant differences in BMD, PTH, CTX or osteocalcin levels between the two groups. However, when older (older than 40 years of age) and younger (40 years of age and younger) cohorts were considered separately, the older GS cohort had significantly decreased total hip BMD, T scores and Z scores, and femoral neck BMD, T scores and Z scores (P<0.005 for each parameter, respectively) compared with older control subjects. Serum osteocalcin levels were lower in the older versus younger GS cohort (P=0.006). An inverse correlation existed between all subjects' serum unconjugated bilirubin levels and total body BMD determinations (r=-0.42; P=0.04). On univariate analysis, the association between serum unconjugated bilirubin and total body BMD was not significant (P=0.066), nor was serum unconjugated bilirubin identified as a risk factor for low BMD when entered into multivariate analyses.

CONCLUSIONS

The results of the present pilot study warrant further research involving larger numbers of subjects and longitudinal measurements to determine whether GS is associated with decreased BMD, particularly in older GS subjects.

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 prevalence among human immunodeficiency virus (HIV)-infected versus non-HIV-infected patients in a large U.S. healthcare system

CONTEXT

Reduced bone mineral density has been demonstrated among HIV-infected patients, but fracture prevalence is unknown.

OBJECTIVE

The objective of the study was to compare fracture prevalence in HIV-infected and non-HIV-infected patients.

DESIGN

This was a population-based study.

SETTING

The study was conducted at a large U.S. health care system.

PATIENTS

A total of 8525 HIV-infected and 2,208,792 non-HIV-infected patients with at least one inpatient or outpatient encounter between October 1, 1996, and March 21, 2008, was compared.

MAIN OUTCOME MEASURE

Fracture prevalence using specific International Classification of Diseases, Ninth Revision, Clinical Modification fracture codes was measured.

RESULTS

The overall fracture prevalence was 2.87 vs. 1.77 patients with fractures per 100 persons in HIV-infected, compared with non-HIV-infected patients (P < 0.0001). Among females, the overall fracture prevalence was 2.49 vs. 1.72 per 100 persons in HIV-infected vs. non-HIV-infected patients (P = 0.002). HIV-infected females had a higher prevalence of vertebral (0.81 vs. 0.45; P = 0.01) and wrist (1.31 vs. 0.83; P = 0.01) fractures per 100 persons, compared with non-HIV-infected females but had a similar prevalence of hip fractures (0.47 vs. 0.56; P = 0.53). Among males, the fracture prevalence per 100 persons was higher in HIV-infected vs. non-HIV-infected patients for any fracture (3.08 vs. 1.83; P < 0.0001), vertebral fractures (1.03 vs. 0.49; P < 0.0001), hip fractures (0.79 vs. 0.45; P = 0.001), and wrist fractures (1.46 vs. 0.99; P = 0.001). Fracture prevalence was higher relative to non-HIV-infected patients among African-American and Caucasian females and Caucasian males.

CONCLUSIONS

Fracture prevalence is increased in HIV-infected compared with non-HIV-infected patients.

CLINICAL Review # : low body weight mediates the relationship between HIV infection and low bone mineral density: a meta-analysis

CONTEXT

HIV infection has been associated with low bone mineral density (BMD) in many cross-sectional studies, although longitudinal studies have not demonstrated accelerated bone loss. The cross-sectional studies may have been confounded by the failure to control for low body weight in HIV-infected patients.

OBJECTIVE

Our objective was to determine whether low body weight might explain the association of HIV infection with low BMD.

DATA SOURCES

MEDLINE and EMBASE were searched for English language studies published from 1966 to March 2007, and conference abstracts prior to 2007 were hand-searched.

STUDY SELECTION

All studies reporting BMD and weight or body mass index in adult patients with HIV and a healthy age- and sex-comparable control group were included. Nine of 40 identified studies and one of 68 identified abstracts were eligible.

DATA SYNTHESIS

We adjusted for the between-groups weight differences using regression coefficients from published cohorts of healthy men and women. On average, HIV-infected patients were 5.1 kg [95% confidence interval (CI), -6.8, -3.4; P < 0.001] lighter than controls. At all skeletal sites, unadjusted BMD was lower by 4.4-7.0% in the HIV-infected groups than the controls (P < 0.01). After adjustment for body weight, residual between-groups differences in BMD were small (2.2-4.7%) [lumbar spine, -0.02 (95% CI, -0.05, 0.01) g/cm2; P = 0.12; total hip, -0.02 (95% CI, -0.04, 0.00) g/cm2; P = 0.031; femoral neck, -0.04 (95% CI, -0.07, -0.01) g/cm2; P = 0.013; and total body, -0.03 (95% CI, -0.07, 0.01) g/cm2, P = 0.11].

CONCLUSION

HIV-infected patients are lighter than controls and low body weight may largely account for the high prevalence of low BMD reported in HIV-infected patients. However, in the setting of current treatment practice, HIV infection per se is not a risk factor for low BMD.