Reduced bone mineral density among HIV infected patients on anti-retroviral therapy in Blantyre, Malawi: Prevalence and associated factors.

INTRODUCTION: Use of tenofovir based anti-retroviral therapy (ART) in HIV patients is associated with low bone mineral density (BMD). Low BMD predisposes people living with HIV (PLWHIV) to fractures thereby increasing morbidity and mortality. Since the introduction of tenofovir based ARV regimens in 2011, information on the prevalence of low BMD in PLWHIV and receiving ART is still scarce in Malawi. This study aimed to determine the prevalence and associated factors of low BMD among adults living with HIV and receiving ART in Blantyre, Malawi. METHODOLOGY: This was a cross sectional study involving 282 HIV-positive adults of whom 102 (36%) were males. The participants aged 18-45 years were recruited from three primary and one tertiary health care facilities. Patients with no other comorbidities or conditions associated with low BMD and on ART >12 months were included. Data on BMD (femoral neck and lumbar spine) were collected using Dual-Energy X-ray Absorptiometry (DEXA). The International Physical Activity Questionnaire (IPAQ) was used to assess the physical activity (PA) levels. Participants' body weight (kg) and height (m) were also measured. Descriptive statistics, Chi-Square test and multivariable logistic regression were used to analyse data. RESULTS: Mean age of participants was 37(± 6.4) years, mean duration on ART was 5(± 3.5) years and mean body mass index (BMI) was 23(± 4.5) kg/m2. Twenty percent (55) had reduced BMD. More males (28%) had reduced BMD than females (14%) (p = 0.04). There was a significant association between lumbar BMD and femoral neck BMD (r = 0.66,p<0.001). However, on average, lumbar BMD (g/cm2) was significantly lower than the femoral BMD (p < 0.001). Participants with low PA level (OR 1.23,p = 0.6) had higher odds of having reduced BMD compared to those with high PA level. CONCLUSIONS AND RECOMMENDATION: Prevalence of reduced BMD is high among PLWHIV in Malawi especially male Malawian adults. Occurrence of low BMD is associated with low PA level. There is need for health care providers to routinely monitor BMD and PA levels of this population.

Veterans Aging Cohort Study Index as a Marker of Bone Disease in HIV-Infected Patients.

People living with human immunodeficiency virus (HIV) infection have higher risk of low bone mineral density (BMD) and fragility fracture than general population. The aim of our retrospective study was to explore if HIV-specific Veterans Aging Cohort Study (VACS) Index and its specific components could help identify patients at risk for low BMD. A total of 195 HIV-infected patients with dual-energy X-ray absorptiometry (DXA) scan between 2007 and 2014 were included and DXA scan results were used to classify patients with osteopenia. VACS Index was calculated for all patients using laboratory values closest to the date of DXA scan. Logistic regression was used to assess the association between VACS Index score or individual components of VACS Index with the presence of low BMD after adjusting for confounding variables. A total of 109 (56%) patients were diagnosed with low BMD. VACS Index score was significantly associated with low BMD, with the odds of low BMD increasing 1.21 times for each 10 unit increase in VACS Index score [confidence interval (95% CI) 1.03-1.42; p = .02]. The two groups differed significantly on patient weights, proportion of white patients, and hepatitis C-coinfected patients. After adjusting for white race and weight, hepatitis C coinfection was significantly associated with increased risk of low BMD (odds ratio 24.4; 95% CI 7.45-80.16). VACS Index score, previously demonstrated to be a marker of frailty in HIV-infected patients, is significantly associated with risk of low BMD and could be used to develop a prediction tool to screen for low BMD in resource-limited setting where DXA scans are not easily available.

Evaluation of screening practices for low bone mass and prevalence of osteoporosis and fractures in people living with human immunodeficiency virus attending a sexual health clinic.

BACKGROUND: Adults with human immunodeficiency virus (HIV) infection commonly experience fractures and have a high prevalence of osteoporosis. The reasons for low bone mineral density (BMD) in HIV patients are multifactorial and there are now guidelines for screening. AIMS: The aims of this study were to determine the screening practices for osteoporosis at this sexual health clinic, the prevalence of osteoporosis and to examine the risk factors for bone disease. METHODS: We performed a retrospective cohort study of all HIV patients attending the Sunshine Coast Health Service District Sexual Health Clinic. Through chart review we collected the following details: patient demographics, co-morbid conditions, HIV status and anti-retroviral therapy, BMD screening, fractures, screening for secondary causes of bone disease and treatment interventions for osteoporosis. RESULTS: A total of 243 patients with HIV attended the sexual health clinic. Of these, 149 met screening criteria for BMD assessment and 93 (61%) of those eligible underwent BMD examination. In those who had a BMD performed, 13 (19%) had sustained a previous fracture, 28 (30%) had osteoporosis and 42 (45%) had osteopenia. In the osteoporosis group, 21 (78%) were treated with vitamin D and calcium, 7 (26%) had a change in ART, 19 (68%) were treated with anti-resorptive therapy and 9 received testosterone replacement. CONCLUSIONS: In this cohort, there was a high prevalence of low bone mass and BMD screening rates of 60%. Our results highlight the importance of this condition and the need to improve screening and availability of BMD assessment.

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.

Reduced bone mineral density in human immunodeficiency virus-infected individuals: a meta-analysis of its prevalence and risk factors.

A meta-analysis was conducted to evaluate the prevalence of osteopenia/osteoporosis in human immunodeficiency virus (HIV)-infected individuals. The prevalence of osteopenia/osteoporosis in HIV-infected and antiretroviral therapy (ART)-treated individuals was significantly higher than respective controls. Evidence regarding bone loss within first year of HIV infection or ART initiation was preliminary. PURPOSE: The aim of the study is to systematically review published literature on the prevalence of osteopenia/osteoporosis and its associated risk factors in HIV-infected individuals. METHODS: A literature search was conducted from 1989 to 2015 in six databases. Full text, English articles on HIV-infected individuals ≥ 18 years, which used dual X-ray absorptiometry to measure BMD, were included. Studies were excluded if the prevalence of osteopenia/osteoporosis was without a comparison group, and the BMD/T-score were not reported. RESULTS: Twenty-one cross sectional and eight longitudinal studies were included. The prevalence of osteopenia/osteoporosis was significantly higher in both HIV-infected [odds ratio (OR) = 2.4 (95%Cl: 2.0, 2.8) at lumbar spine, 2.6 (95%Cl: 2.2, 3.0) at hip] and ART-treated individuals [OR = 2.8 (95%Cl: 2.0, 3.8) at lumbar spine, 3.4 (95%Cl: 2.5, 4.7) at hip] when compared to controls. PI-treated individuals had an OR of 1.3 (95%Cl: 1.0, 1.7) of developing osteopenia/osteoporosis compared to controls. A higher proportion of tenofovir-treated individuals (52.6%) had lower BMD compared to controls (42.7%), but did not reach statistical significance (p = 0.248). No significant difference was found in the percent change of BMD at the lumbar spine, femoral neck, or total hip from baseline to follow-up between HIV-infected, PI-treated, tenofovir-treated, and controls. Older age, history of bone fracture, low BMI, low body weight, being Hispanic or Caucasian, low testosterone level, smoking, low CD4 cell count, lipodystrophy, low fat mass, and low lean body mass were associated with low BMD. CONCLUSIONS: The prevalence of osteopenia/osteoporosis in HIV-infected and antiretroviral therapy (ART)-treated individuals was two times more compared to controls. However, evidence concerning bone loss within the first year of HIV infection and ART initiation was preliminary.

Low bone mineral density among HIV-infected patients in Brazil.

Decrease in bone mineral density (BMD) has been a complication among people living with HIV/AIDS. To investigate the prevalence of osteopenia/osteoporosis among HIV-infected people living in São Paulo city, we studied 108 HIV-infected patients (79 men and 29 women). We extracted data from patients' medical records and BMD was measured by dual-energy X-ray absorptiometry (DXA). Median age of participants was 42 years (interquartile range [IQR] 36-48 years), and the median time since HIV diagnosis was 4.01 years (IQR 2-11 years). Patients had acquired HIV primarily by the sexual route (men who have sex with men 44%, heterosexual 49%). Median age, duration of HIV infection, duration of ART and CD4 nadir were similar for men and women. Plasma viral load was undetectable for 53 patients (49%). Median CD4 T cell count was 399 cells/µL (IQR 247 - 568). Twenty five patients (23%) had LBMD, and there was no statistically significant difference between men and women (<-1). The associated risk factors for LBMD were older age (≥ 50 years old) and smoking with a RR of 3.87 and 2.80, respectively. Thus, despite the lack of statistically significant relationship between the use of ART and LBMD or between duration of ART and LBMD, these factors should be addressed in larger studies.

Osteoporosis and osteopenia are not associated with T-cell activation in older cART-treated HIV-infected patients.

BACKGROUND: A higher risk of developing osteopenia/ osteoporosis has been seen in HIV-infected patients. We compared HIV-infected patients, all treated with combination antiretroviral therapy (cART), with a low bone mineral density (BMD) (T-score < -1) to those with a normal BMD (T-score > -1), examining the relation with T-cell activation and bone turnover markers (c-terminal telopeptide (CTX) and procollagen type 1 amino-terminal propeptide (P1NP)). METHODS: In this single visit pilot study, bone turnover markers, T-cell activation (CD38 + HLA - DR +) and senescence (CD57+) of T cells were measured in patients who had previously undergone dual energy X-ray absorptiometry scanning. RESULTS: All study participants (n = 16) were male, on cART, with a median age of 61 years (IQR 56-66). Nine patients had osteopenia/osteoporosis. When comparing the patients with osteopenia/osteoporosis with those with a normal BMD, no differences in activation and senescence were found. A relation was seen between higher bone formation (P1NP) and patients who were on cART for longer. The median length of cART use was 5.5 years (IQR 4.5-7.8), with all patients on nucleoside reverse transcriptase inhibitors, 88% on tenofovir, 63% on non-nucleoside reverse transcriptase inhibitors (NNRTIs) and 38% on protease inhibitors. Osteopenia/osteoporosis was seen in 100% of the patients on protease inhibitors versus 30% of those on NNRTIs. CONCLUSION: This study did not find an association between activated T cells and BMD, thus did not explain the higher prevalence of osteopenia/osteoporosis in HIV-infected patients. Interestingly, this small pilot showed that cART might influence BMD, with a possible negative effect for protease inhibitors and a possible protective effect for NNRTIs. These results warrant further investigation.

Frailty in HIV infected people: a new risk factor for bone mineral density loss.

OBJECTIVE: The study aims to assess the association between bone mineral density (BMD) and frailty in a cohort of HIV-infected patients. DESIGN: A cross-sectional study in an HIV outpatient unit where nearly 1000 patients are monitored. METHODS: Study participants undergoing bone densitometry were proposed an evaluation of frailty using criteria of the Cardiovascular Health Study (CHS) and the Study of Osteoporotic Fractures (SOF). Frailty markers were weight-loss, self-reported exhaustion, physical activity, grip strength, chair stands, and slow gait. Patients' characteristics were collected from an electronic medical record. Associations of frailty with BMD and osteoporosis were tested using multivariate linear and logit regression models, respectively. RESULTS: In total, 175 HIV-infected patients, 121 (69.14%) men, were analyzed. Prevalence of frailty markers, osteopenia, and osteoporosis were comparable among sexes. Despite a younger age, spinal and femoral neck BMD were lower in women (P < 0.05). Linear regression model adjusting by age, duration of HIV follow-up, BMI, smoking status, osteoarthritis, osteoporosis treatment, and the age at menopause showed a negative association of spinal and femoral BMD with frailty according to SOF criteria in women (P < 0.05). In men, SOF-defined frailty was associated with osteoporosis (odds ratio 28.79; 95% confidence interval 2.15-386.4) in a model adjusting for age, duration of HIV follow-up, CD4 nadir, CD4 T-cell count, tobacco consumption, exposure to tenofovir (TDF) and protease inhibitors. No significant associations were found between BMD and CHS-defined frailty. CONCLUSION: Our study shows that frailty according to SOF criteria is associated with low spinal BMD values in female and osteoporosis in male HIV-infected patients.

Brief Report: Macrophage Activation in HIV-Infected Adolescent Males Contributes to Differential Bone Loss by Sex: Adolescent Trials Network Study 021.

Accumulating evidence suggests that rates of low bone mass are greater in HIV-infected males than females. Of 11 biomarkers assessed by sex and HIV-status, HIV-infected males had increased levels of soluble CD14 which inversely correlated with bone mineral content and bone mineral density measures, suggesting macrophage activation as a possible mechanism of differential bone loss.

High Prevalence of Low Bone Mineral Density and Substantial Bone Loss over 4 Years Among HIV-Infected Persons in the Era of Modern Antiretroviral Therapy.

HIV-infected persons are living longer on combination antiretroviral therapy (cART) but experiencing more comorbidities including low bone mineral density (BMD). Using data from the Study to Understand the Natural History of HIV and AIDS in the Era of Effective Therapy (SUN Study), we determined the prevalence of low BMD (T-score below one standard deviation of the reference mean) and compared it with matched controls from the National Health and Nutrition Examination Survey (NHANES). We also assessed 4-year longitudinal BMD changes among participants virologically suppressed on cART. Of 653 participants included in this analysis (77% male, 29% black, median age 41 years, median CD4(+) cell count 464 cells/mm(3), 89% with HIV RNA <400 copies/ml), 51% and 10% had baseline osteopenia and osteoporosis, respectively. Low BMD at the femoral neck was significantly more prevalent than for the NHANES controls (47% versus 29%, p<0.001). Lower body mass index, nonwhite race, longer tenofovir exposure, older age, being unemployed or retired, and lower apolipoprotein E were independently associated with baseline osteoporosis. Among 170 participants virologically suppressed on cART and with longitudinal BMD data, 31% experienced substantial bone loss (≥5% BMD decline from baseline) over 4 years. Female sex, current smoking, and longer stavudine use were more common among participants who had substantial bone loss, although these variables failed to reach statistical significance. Low BMD was highly prevalent among HIV-infected persons. One-third of participants experienced substantial bone loss despite cART, suggesting the need for monitoring and potential clinical interventions.

Serum total estradiol, but not testosterone is associated with reduced bone mineral density (BMD) in HIV-infected men: a cross-sectional, observational study.

SUMMARY: By investigating the relationship between serum testosterone, estradiol, and bone mineral density (BMD) in a large cohort of HIV-infected men, estradiol was associated with BMD, relative estrogen deficiency being involved in bone loss in men with hypogonadism, in addition to all HIV-related factors. Increased aromatization in adipose tissue does not counteract HIV-related bone loss. INTRODUCTION: The purpose of this study is to evaluate the relationship between serum testosterone, estradiol, and BMD in a large cohort of HIV-infected men. METHODS: We investigated biochemical, hormonal parameters, and BMD in 1204 HIV-infected men (age 45.64 ± 7.33 years) participating in a cross-sectional, observational study. Among other parameters, the main outcome measures were serum total testosterone and estradiol, gonadotropins, 25-hydroxyvitamin D [25(OH)D], parathormone (PTH), calcium, phosphorous, femoral, and lumbar BMD. RESULTS: In men with HIV, the prevalence of osteoporosis and osteopenia is 15.1 and 63.2% with 25(OH)D insufficiency being very common (60.1%). After age adjustment, BMD is positively associated with estradiol, but not testosterone, at linear (p < 0.001) and stepwise (p < 0.05) multiple regression. Lumbar BMD significantly increases across the estradiol quartiles but not among testosterone quartiles. Femoral and lumbar BMD are significantly higher in men with estradiol ≥ 27 pg/mL than in those with estradiol <27 pg/mL. Apart from estradiol, only age, calcium, and BMI predict BMD at stepwise linear multiple regression, but the strength of this association is weak. CONCLUSIONS: Estradiol, but not testosterone, is associated with BMD in HIV-infected men and exerts a protective role on bone especially when it is above 27 pg/mL. Relative estrogen deficiency is a potential mechanism involved in bone loss in hypogonadal HIV-infected men, in addition to all HIV-related factors. Increased aromatization in adipose tissue does not counteract HIV-related bone loss. Finally, reduced BMD in young-to-middle-aged HIV-infected men might be considered a peculiar hallmark of HIV infection due to its relevant prevalence, representing one of the several pieces composing the complicated puzzle of premature aging related to HIV infection.

Is there enough evidence to use bisphosphonates in HIV-infected patients? A systematic review and meta-analysis.

An increased prevalence of osteopenia and osteoporosis has been observed in HIV-infected cohorts. We investigated the effect of bisphosphonates on bone mineral density in adults with HIV infection. Outcomes of interest were bone mineral density changes measured by dual-energy X-ray absorptiometry at the lumbar spine, femoral neck, and total hip, and adverse events. Data were pooled using the fixed-effects model. We identified eight randomized controlled trials meeting our inclusion criteria, involving 328 participants. Five trials compared alendronate with placebo or no intervention; in three trials the intervention arm received zoledronate. A significant increase in bone mineral density at the lumbar spine was observed in the bisphosphonate group at 48 weeks (MD: 2.84%; 95% CI: 2.11-3.57) and 96 weeks (MD: 6.76%; 95% CI: 4.98-8.54); analogously, bisphosphonates were associated with an increase in total hip bone mineral density at 48 weeks (MD: 2.12%; 95% CI: 1.43-2.81) and 96 weeks (MD: 3.2%; 95% CI: 1.52-4.88). Bisphosphonates were generally well tolerated; no drug-related withdrawals were reported in the five randomized controlled trials assessing alendronate, whereas two patients out of 104 receiving zoledronate experienced acute-phase reactions. In conclusion, administration of oral and intravenous bisphosphonates was associated with increased bone mineral density at the lumbar spine and total hip over two years in HIV-positive patients. However, none of the included trials were long enough to detect the impact of bisphosphonates on a clinically important outcome such as fracture risk. Larger studies with extended follow-up are warranted.

Role of bone mineral density in predicting morphometric vertebral fractures in patients with HIV infection.

UNLABELLED: This study investigated the bone of HIV patients both in terms of quantity and quality. It was found that HIV-infected patients did fracture independently of the degree of bone demineralization as in other forms of secondary osteoporosis. INTRODUCTION: We aimed to determine the prevalence of vertebral fractures (VFs) in HIV patients who were screened by bone mineral density (BMD) and to explore possible factors associated with VFs. METHODS: This is a cross-sectional study that included HIV-infected patients recruited in the Clinic of Infectious and Tropical Diseases and that underwent BMD measurement by dual-energy X-ray absorptiometry (DXA) at the lumbar spine and hip (Lunar Prodigy, GE Healthcare). For the assessment of VFs, anteroposterior and lateral X-ray examinations of the thoracic and lumbar spines were performed and were centrally digitized. Logistic regression models were used in the statistical analysis of factors associated with VFs. RESULTS: One hundred thirty-one consecutive patients with HIV infection (93 M, 38 F, median age 51 years; range, 36-75) underwent BMD measurement: 25.2 % of patients showed normal BMD, while 45 % were osteopenic and 29.7 % osteoporotic. Prevalence of low BMD (osteopenia and osteoporosis) was higher in females as compared to males (90 vs 69 %) with no significant correlation with age and body mass index. VFs occurred more frequently in patients with low BMD as compared to patients with normal BMD (88.5 vs. 11.4 %; p < 0.001) without any significant difference between osteopenia and osteoporosis (43 vs. 46 %; p = 0.073). VFs were significantly associated with older age and previous AIDS events. CONCLUSIONS: These results suggest a BMD <-1 threshold to identify patients at risk of skeletal fragility and, therefore, good candidates for morphometric evaluation of spine X-ray in line with other forms of secondary osteoporosis with impaired bone quality.

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.

UNLABELLED: 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.

Efficacy of different therapeutic regimens on hepatic osteodystrophy in chronic viral liver disease.

BACKGROUND AND AIMS: Metabolic bone disease is common in patients with chronic liver disease. Comparative studies on the efficacies of antiosteoporotic agents in hepatic osteodystrophy have not been conducted yet. The aim of this study was to evaluate the safety and efficacy of different therapeutic regimens on hepatic osteodystrophy. METHODS: Eighty-one patients (mean age 48.9 ± 10 years; 50 cases with chronic viral hepatitis and 31 patients with cirrhosis) were enrolled in the study. Treatment groups consisted of 61 patients who had reduced T scores in at least one region, selected randomly and treated for 1 year with vitamin D 400 IU, calcitonin 200 IU, alendronate 10 mg, alendronate 70 mg, or risedronate 5 mg. An untreated group consisting of 20 patients who had no reduction in T scores was followed up during the study period. RESULTS: No significant adverse effects, including esophageal variceal hemorrhage, were detected. According to the T score at the end of the first year compared with baseline, significant improvements in bone mineral density were observed at all regions with alendronate 70 mg; improvements at the lumbar spine (LS) and distal radius regions with alendronate 10 mg; at the LS and distal radius regions with risedronate; at the LS region with calcitonin; and at the femoral neck region with vitamin D. CONCLUSION: All therapeutic regimens seemed to be safe, and oral biphosphonates were the most effective in preventing both cortical and trabecular bone loss in patients with chronic viral liver disease. Larger studies with longer follow-up are warranted in hepatic osteodystrophy of chronic viral liver diseases.

Aging, human immunodeficiency virus, and bone health.

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

HIV-1 Tat protein enhances RANKL/M-CSF-mediated osteoclast differentiation.

Impaired osteoblast/osteoclast cross-talk and bone structure homeostasis resulting in osteopenia/osteoporosis are often observed in HIV seropositive patients but the causal mechanisms remain unsettled. This study analyzed the biological effects of Tat on peripheral blood monocyte-derived osteoclast differentiation. Tat enhances osteoclast differentiation and activity induced by RANKL plus M-CSF treatment increasing both the mRNA expression of specific osteoclast differentiation markers, such as cathepsin K and calcitonin receptor, and TRAP expression and activity. These Tat-related biological effects may be related, at least in part, to the induction of c-fos expression and AP-1 activity. c-fos up-regulation was triggered by Tat when cell cultures were co-treated with RANKL/M-CSF and an analysis of c-fos promoter with c-fos deletion mutant constructs disclosed specific c-fos promoter domains targeted by Tat. Together, these results show that Tat may be considered a viral factor positively modulating the osteoclastogenesis and then bone resorption activity suggesting a pathogenetic role of this viral protein in the HIV-related osteopenia/osteoporosis.

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.

A double-blinded, randomized controlled trial of zoledronate therapy for HIV-associated osteopenia and osteoporosis.

OBJECTIVE: To evaluate the efficacy of a single dose of intravenous zoledronate for the treatment of HIV-associated osteopenia and osteoporosis. DESIGN: A double-blinded, randomized, placebo-controlled, 12-month trial of 5 mg intravenous zoledronate dose to treat 30 HIV-infected men and women with osteopenia and osteoporosis. METHODS: Following zoledronate or placebo infusions, participants were followed for 12 months on daily calcium and vitamin D supplements. Lumbar spine and hip bone density was assessed at baseline, 6 and 12 months. Biomarkers of bone metabolism were measured at baseline, 2 weeks, 3, 6, 9, and 12 months. Student's t-test and repeated measure analyses were used to evaluate bone density and bone marker changes over time. RESULTS: In the 30 HIV-infected individuals [men (27) and women (3)] in the trial, median T-scores at entry were -1.7 for the lumbar spine and -1.4 for the hip. Median CD4 cell count was 461 cells/microl, 93% had HIV-RNA viral loads less than 400 copies/ml, and 97% were taking antiretroviral medications. Bone density measured either absolutely or as sex-adjusted T-scores significantly improved in zoledronate recipients as compared with minimal changes in those receiving placebo. Bone resorption markers significantly decreased over the study period in the zoledronate recipients as compared with placebo controls. No acute infusion reactions were detected, but one patient developed uveitis, a recognized complication of zoledronate, which responded to therapy. CONCLUSION: In this small study, annual zoledronate appears to be a well tolerated and effective therapy for HIV-associated bone loss.

Growth hormone and bone mineral densitiy in HIV-1-infected male subjects.

The aim of this study was to characterize the GH-IGF-I axis of patients with HIV-1-infection without any symptoms of AIDS-associated wasting. A special emphasis was placed on determine bone mineral density (BMD) and biochemical markers of bone metabolism. Therefore 42 male fasting HIV-1-infected outpatients were included and estimation of serum GH, IGF-I, IGFBP-1 and 3, osteocalcin, TNF-alpha, 1,25dihydroxycholecalciferol, and endocrine markers of the gonad function by commercially available RIA's performed. DEXA-measurements of the lumbar spine and the Ward's triangle of the left hip were done. The GH, IGF-1, IGFBP-1 and 3 serum levels were within the normal range Performing Spearman-correlation test, we established significance between IGF-I serum levels and BMD lumbar spine and Ward's triangle (p < 0.01, p < 0.05), CD4 cell-count (p < 0.05), 1,25dihydroxycholecalciferol (p < 0.05), osteocalcin (p < 0.05), TNF-alpha (p < 0.05), body mass index (BMI) (p < 0.05) and total testosterone (p < 0.01). IGFBP-1 correlates both inversely significantly with CD4 cell-count (p < 0.05) and serum-calcium (p < 0.05). The IGFBP-3 correlates with BMI (p < 0.05) and serum osteocalcin (p < 0.05). Correlation both with markers of bone metabolism and vitamin D metabolites showed the important role of GH/IGF-I axis in modulating the availability of calcium in chronic conditions. This axis may be in a part responsible for the manifestation of the HIV-associated osteopenia.