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

Bone mineral density among virologically suppressed Asians older than 50 years old living with and without HIV: A cross-sectional study

There are limited data regarding bone health in older people living with HIV (PWH), especially those of Asian ethnicity. We aimed to determine whether BMD in well-suppressed HIV-infected men and women aged ≥ 50 years are different from HIV-uninfected controls. In a cross-sectional study, BMD by dual-energy X-ray absorptiometry and calciotropic hormones were measured. A total of 481 participants were consecutively enrolled (209 HIV+ men, 88 HIV- men, 126 HIV+ women and 58 HIV- women). PWH were on average 2.5 years younger [men: 55.0 vs. 57.5 yr; women: 54.0 vs. 58.0 yr] and had lower body mass index (BMI) [men: 23.2 vs. 25.1 kg/m2; women: 23.1 vs. 24.7 kg/m2] compared to the controls. The median duration since HIV diagnosis was 19 (IQR 15-21) years in men and 18 (IQR 15-21) years in women. Three-quarters of PWH had been treated with tenofovir disoproxil fumarate-containing antiretroviral therapy for a median time of 7.4 (IQR 4.5-8.9) years in men and 8.2 (IQR 6.1-10) years in women. In an unadjusted model, HIV+men had significantly lower BMD (g/cm2) at the total hip and femoral neck whereas there was a tend toward lower BMD in HIV+women. After adjusting for age, BMI, and other traditional osteoporotic risk factors, BMD of virologically suppressed older PWH did not differ from participants without HIV (P>0.1). PWH had lower serum 25(OH)D levels but this was not correlated with BMD. In conclusion, BMD in well-suppressed PWH is not different from non-HIV people, therefore, effective control of HIV infection and minimization of other traditional osteoporosis risk factors may help maintain good skeletal health and prevent premature bone loss in Asian PWH. Clinical trial registration: Clinicaltrials.gov # NCT00411983.

The effect of anti-retroviral therapy on fracture healing : an in vivo animal model

AIMS

A number of anti-retroviral therapies (ART) have been implicated in potentially contributing to HIV-associated bone disease. The aim of this study was to evaluate the effect of combination ART on the fracture healing process.

METHODS

A total of 16 adult male Wistar rats were randomly divided into two groups (n = eight each): Group 1 was given a combination of Tenfovir 30 mg, Lamivudine 30 mg, and Efavirenz 60 mg per day orally, whereas Group 2 was used as a control. After one week of medication preload, all rats underwent a standardized surgical procedure of mid-shaft tibial osteotomy fixed by intramedullary nail with no gap at the fracture site. Progress in fracture healing was monitored regularly for eight weeks. Further evaluations were carried out after euthanasia by micro-CT, mechanically and histologically. Two blinded orthopaedic surgeons used the Radiological Union Scoring system for the Tibia (RUST) to determine fracture healing.

RESULTS

The fracture healing process was different between the two groups at week 4 after surgery; only two out of eight rats showed full healing in Group 1 (ART-treated), while seven out of eight rats had bone union in Group 2 (control) (p = 0.040). However, at week eight postoperatively, there was no statistical difference in bone healing; seven out of eight progressed to full union in both groups.

CONCLUSION

This study demonstrated that combination ART resulted in delayed fracture healing at week 4 after surgery in rats, but did not result in the development of nonunion.Cite this article: Bone Joint Res 2022;11(8):585-593.

Impact of postpartum tenofovir-based antiretroviral therapy on bone mineral density in breastfeeding women with HIV enrolled in a randomized clinical trial

Objectives

We set out to evaluate the effect of postnatal exposure to tenofovir-containing antiretroviral therapy on bone mineral density among breastfeeding women living with HIV.

Design

IMPAACT P1084s is a sub-study of the PROMISE randomized trial conducted in four African countries (ClinicalTrials.gov number NCT01066858).

Methods

IMPAACT P1084s enrolled eligible mother-infant pairs previously randomised in the PROMISE trial at one week after delivery to receive either maternal antiretroviral therapy (Tenofovir disoproxil fumarate / Emtricitabine + Lopinavir/ritonavir–maternal TDF-ART) or administer infant nevirapine, with no maternal antiretroviral therapy, to prevent breastmilk HIV transmission. Maternal lumbar spine and hip bone mineral density were measured using dual-energy x-ray absorptiometry (DXA) at postpartum weeks 1 and 74. We studied the effect of the postpartum randomization on percent change in maternal bone mineral density in an intention-to-treat analysis with a t-test; mean and 95% confidence interval (95%CI) are presented.

Results

Among 398/400 women included in this analysis, baseline age, body-mass index, CD4 count, mean bone mineral density and alcohol use were comparable between study arms. On average, maternal lumbar spine bone mineral density declined significantly through week 74 in the maternal TDF-ART compared to the infant nevirapine arm; mean difference (95%CI) -2.86 (-4.03, -1.70) percentage points (p-value <0.001). Similarly, maternal hip bone mineral density declined significantly more through week 74 in the maternal TDF-ART compared to the infant nevirapine arm; mean difference -2.29% (-3.20, -1.39) (p-value <0.001). Adjusting for covariates did not change the treatment effect.

Conclusions

Bone mineral density decline through week 74 postpartum was greater among breastfeeding HIV-infected women randomized to receive maternal TDF-ART during breastfeeding compared to those mothers whose infants received nevirapine prophylaxis.

Association between Antiretroviral Treatment and Markers of Systemic Inflammation among HIV Patients in Ghana

BACKGROUND

Studies from high-income countries have reported that even after receiving antiretroviral treatment (ART), HIV-infected adults may not achieve normal levels of certain inflammatory markers that are known to be associated with the onset and development of non-communicable diseases.

OBJECTIVE

The aim of this study is to examine the relationship between ART and markers of systemic inflammation in HIV/AIDS patients at an urban antiretroviral clinic in Ghana.

METHODS

We examined serum levels of high sensitivity CRP (hsCRP), interleukin-6 (IL-6), interleukin- 18(IL-18), and tumor necrosis factor-α (sTNFR1 and sTNFR2) from 40 HIV infected patients. Kruskal-Wallis Test was used to examine the differences in markers of systemic inflammation according to the types of ART medication taken. We then utilized generalized additive models (GAM) with non-linear function to examine the association between ART and markers of systemic inflammation after adjusting for potential confounders.

RESULTS

Overall, 30 (75.0%) of the participants received ART and 35 (85%) were female. Kruskal- Wallis Test revealed no significant differences in the markers of systemic inflammation among the three categories of ART (none, AZT, 3TC, EFV/NVP, and TDF, 3TC/FTC, EFV/NVP). In the multivariable- adjusted GAM model, we found a significant but non-linear association between time since diagnosis and CRP levels (p=0.006).

CONCLUSION

Although the relatively small sample size limits the scope of the study's findings, these results suggest that individuals on ART need to be screened periodically for the development of chronic conditions. This line of investigation has the potential to influence treatment and clinical guidelines that will improve the quality of care for HIV-infected patients.

Treatment of Human Immunodeficiency Virus Infection With Tenofovir Disoproxil Fumarate-Containing Antiretrovirals Maintains Low Bone Formation Rate, But Increases Osteoid Volume on Bone Histomorphometry

Bone mineral density (BMD) loss is a known complication of human immunodeficiency virus (HIV) infection and its treatment, particularly with tenofovir disoproxil fumarate (TDF)-containing antiretroviral regimens. Although renal proximal tubular dysfunction and phosphaturia is common with TDF, it is unknown whether BMD loss results from inadequate mineralization. We evaluated change in BMD by dual-energy X-ray absorptiometry (DXA) and bone histomorphometry by tetracycline double-labeled transiliac crest biopsies in young men living with HIV before (n = 20) and 12 months after (n = 16) initiating TDF/lamivudine/efavirenz. We examined relationships between calciotropic hormones, urinary phosphate excretion, pro-inflammatory and pro-resorptive cytokines, and bone remodeling-related proteins with changes in BMD and histomorphometry. Mean age was 29.6 ± 5.5 years, with mean CD4 + T cell count of 473 ± 196 cells/mm³ . At baseline, decreased bone formation rate and increased mineralization lag time were identified in 16 (80%) and 12 (60%) patients, respectively. After 12 months, we detected a 2% to 3% decrease in lumbar spine and hip BMD by DXA. By histomorphometry, we observed no change in bone volume/total volume (BV/TV) and trabecular parameters, but rather, increases in cortical thickness, osteoid volume, and osteoblast and osteoclast surfaces. We did not observe significant worsening of renal phosphate excretion or mineralization parameters. Increases in PTH correlated with decreased BMD but not histomorphometric parameters. Overall, these data suggest abnormalities in bone formation and mineralization occur with HIV infection and are evident at early stages. With TDF-containing antiretroviral therapy (ART), there is an increase in bone remodeling, reflected by increased osteoblast and osteoclast surfaces, but a persistence in mineralization defect, resulting in increased osteoid volume. © 2019 American Society for Bone and Mineral Research.

Switch from tenofovir disoproxil fumarate combination to dolutegravir with rilpivirine improves parameters of bone health

Objective:

Bone mineral density (BMD) loss, a risk factor for osteoporosis, has been attributed to HIV infection and antiretroviral therapy (ART), including regimens containing tenofovir disoproxil fumarate.

Design:

Study 202094 is an open-label, parallel-group, sub-study of the phase III SWORD-1 and SWORD-2 studies (ClinicalTrials.gov identifier, NCT02478632).

Methods:

HIV-1-infected adults with HIV-1 RNA less than 50 copies/ml who received ART containing tenofovir disoproxil fumarate for at least 6 months were randomized to receive dolutegravir with rilpivirine or continue current ART regimen. Total hip and lumbar spine BMD were measured by dual-energy X-ray absorptiometry (DXA) scans. The primary endpoint was percentage change from baseline in total hip BMD.

Results:

DXA scans were evaluable for 81 participants at baseline and Week 48. Percentage increase in total hip BMD was significantly greater in participants who switched to dolutegravir with rilpivirine (1.34%) compared with participants who continued current ART (0.05%; treatment difference, +1.29%; 95% CI 0.27–2.31; P = 0.014). Lumbar spine BMD significantly increased in the dolutegravir with rilpivirine group by 1.46% (95% CI 0.65–2.28) compared with 0.15% (95% CI –0.79 to 1.09) in the current ART group (treatment difference, 1.32; 95% CI 0.07–2.57; P = 0.039). Participants in the dolutegravir with rilpivirine group experienced significantly greater reductions in bone formation and resorption biomarkers compared with the current ART group.

Conclusion:

Switch to dolutegravir with rilpivirine was associated with significant improvement in BMD and bone turnover markers compared with tenofovir-based three-drug regimens, providing a robust option for preserving bone health while continuing suppressive ART.

Bone mineral density in people living with HIV: a narrative review of the literature

Bone health status is largely absent in South Africa, the main reasons being the absence and cost-effectiveness of specific screening equipment for assessing bone mineral density (BMD). Various risk factors seem to play a role, some of which can be modified to change bone health status. Urbanisation is also a public health concern. Changing nutritional, as well as social behaviour, play integral roles in the prevalence and incidence of decreased BMD. Furthermore, human immunodeficiency virus (HIV) specifically, has a negative impact on BMD and although highly active antiretroviral therapy increases the prognosis for HIV-infected individuals, BMD still seem to decrease further. Dual energy X-ray absorptiometry is considered the gold standard for BMD assessment; however, recent developments have provided more cost-effective screening methods, among which heel quantitative ultrasound appears to be the most widely used in resource limited countries such as South Africa.

Predictors of longitudinal change in bone mineral density in a cohort of HIV-positive and negative patients

OBJECTIVE

Although low bone mineral density (BMD) is prevalent in HIV, changes in BMD over time remain unclear. We aimed to compare rates of, and factors associated with, BMD change between HIV-positive and HIV-negative patients.

METHODS

In a prospective, 3-year cohort, HIV-positive and HIV-negative patients provided annual demographic and clinical data, fasting bloods, and dual x-ray absorptiometry. Using longitudinal mixed models we compared and determined predictors of rate of change in BMD.

RESULTS

Of 384 study participants (45.8% HIV positive), 120 contributed two and 264 contributed three BMD measurements. Those with HIV were younger [median interquartile range 39 (34-46) vs. 43 (35-50) years; P = 0.04], more often men (61 vs. 46%; P = 0.003), and less likely Caucasian (61 vs. 82%; P < 0.001). Although BMD was lower in those with HIV, BMD declined in both groups, with nonsignificant between-group difference in rate of BMD change over time. Within the HIV group, starting antiretroviral therapy (ART) within 3 months of enrolment was associated with greater BMD decline at all anatomical sites (all P < 0.001). Age more than 30 years, Caucasian ethnicity, and not being on ART during follow-up were associated with greater decline and higher parathyroid hormone associated with a smaller decline in BMD at the femoral neck. We found no association between BMD change and exposure to tenofovir disoproxil fumarate or protease inhibitors.

CONCLUSION

We observed no difference in rate of BMD decline regardless of HIV status and in HIV-positive patient, having started ART within the previous 3 months was the only factor associated with greater BMD decline at all three sites.

Disrupted trabecular bone micro-architecture in middle-aged male HIV-infected treated patients

OBJECTIVES

HIV-infected individuals are at increased risk of incident fractures. Evaluation of trabecular bone micro-architecture is an important tool to assess bone strength, but its use has not yet been reported in middle-aged HIV-infected male individuals. The aim of the study was to compare bone micro-architecture between HIV-infected and HIV-uninfected men.

METHODS

In this cross-sectional study, 53 HIV-infected male individuals with a mean (± standard deviation) age of 49 ± 9 years who had been receiving antiretroviral therapy including tenofovir disoproxil fumarate (DF) for at least 60 months were compared with 50 HIV-uninfected male controls, matched for age and ethnic origin. We studied the volumetric bone density and micro-architecture of the radius and tibia using high-resolution peripheral quantitative computed tomography (HR-p QCT).

RESULTS

Volumetric trabecular bone density was 17% lower in the tibia (P < 10(-4) ) and 16% lower in the radius (P < 10(-3) ) in HIV-infected patients compared with controls. By contrast, the cortical bone density was normal at both sites. The tibial trabecular micro-architecture differed markedly between patients and controls: bone volume/total volume (BV/TV) and trabecular number were each 13% lower (P < 10(-4) for both). Trabecular separation and inhomogeneity of the network were 18% and 24% higher in HIV-infected patients than in controls, respectively. The radial BV/TV and trabecular thickness were each 13% lower (P < 10(-3) and 10(-2) , respectively). Cortical thickness was not different between the two groups.

CONCLUSIONS

The findings of lower volumetric trabecular bone density and disrupted trabecular micro-architectural parameters in middle-aged male HIV-infected treated patients help to explain bone frailty in these patients.

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

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

Increased bone resorption during tenofovir plus lopinavir/ritonavir therapy in Chinese individuals with HIV

We sought to evaluate the effects of antiretroviral therapy on skeletal metabolism in Chinese individuals with human immunodeficiency virus. Patients switched to tenofovir/lamivudine + lopinavir/ritonavir after treatment failure had an increase in bone resorption marker levels by nearly 60%, which is greater than the magnitude previously described in non-Chinese populations.

INTRODUCTION

Few studies have evaluated the effects of antiretroviral therapy on skeletal metabolism in Asian populations infected with human immunodeficiency virus (HIV).

METHODS

We performed a secondary analysis of bone turnover markers (BTM) at baseline and 2 years in stored plasma samples collected from 2/2009 to 1/2013 as part of a multi-center trial. Two groups were compared: (1) treatment-naïve patients initiated on zidovudine (AZT)/lamivudine (3TC) plus nevirapine (NVP) and (2) patients who failed first-line therapy and were switched to tenofovir (TDF)/3TC plus lopinavir/ritonavir (LPVr). Tests included the bone resorption marker, C-terminal cross-linking telopeptide of type-1 collagen (CTX), and the bone formation marker procollagen type 1 N-terminal propeptide (P1NP).

RESULTS

In the TDF/3TC + LPVr group, samples were available from 59 patients at baseline and 56 patients at 2 years. Of these, 36 patients had samples available from both time points. In the AZT/3TC + NVP group, plasma samples were analyzed from 82 participants at baseline and of those, 61 had samples at 2 years. Median change over 2 years was greater in the TDF/3TC + LPVr group for both CTX (+0.24 ng/mL, interquartile ranges (IQR) 0.10-0.43 vs. +0.09 ng/mL, IQR -0.03 to 0.18, p = 0.001) and P1NP (+25.5 ng/mL, IQR 2.4-51.3 vs. +7.11 ng/mL, IQR -4.3 to 21.6, p = 0.012). Differences remained after adjusting for potential confounders in the multivariable analysis.

CONCLUSIONS

Switching to TDF/3TC + LPVr after treatment failure resulted in greater increases in BTMs than initiation with AZT/3TC + NVP in Chinese patients with HIV. Following this change, bone resorption marker levels increased by nearly 60 %, which is greater than the 25-35% increase from baseline described previously in non-Chinese populations. Further studies are warranted to elucidate these findings.

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

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

Bone mineral density changes after 2 years of ARV treatment, compared to naive HIV-1-infected patients not on HAART

BACKGROUND

The prevalence of osteopenia and osteoporosis is increased in human immunodeficiency virus (HIV)-infected patients. The pathogenesis of this low bone mineral density (BMD) is multifactorial.

METHODS

We conducted a prospective study over a 2-year period of the BMD in non-treated ARV-naïve HIV-infected-males, in comparison to HIV-infected males commencing a first ARV treatment, and analyzed the evolution of bone turnover markers.

RESULTS

A total of 39 caucasian males (median age 38.6 years) were enrolled, including 10 who started ARV treatment (group 1), and 29 without indications for ARV therapy (group 2). In the latter group, 11 subjects commenced ARV during the study; therefore the remainder of their follow-up was within group 1, which finally consisted of 21 patients. At baseline, 9 patients (19.5%) had osteoporosis at least at 1 site, while 28 (61%) showed osteopenia. Lower BMD was correlated with tobacco use. Lumbar spine and total hip BMD significantly decreased in group 1 patients after 6 months of treatment, then stabilized (2.4% and 4% loss, respectively, at 24 months), while no significant change in BMD was observed in group 2 subjects. At baseline, one patient had an increased CTX (C-terminal cross-linking telopeptide of type 1 collagen) and all BSAP (bone-specific alkaline phosphatase) results were normal. During follow-up, both CTX and BSAP increased in group 1 patients, while they did not change in group 2.

CONCLUSION

Osteoporosis and osteopenia are frequent in HIV-infected males. After ARV initiation, BMD decreased, and bone turnover markers increased, even though the BMD remained stable in non-treated patients. These results underline the impact of HIV treatment on BMD and bone metabolism.

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

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 effects of randomized regimen and nucleoside reverse transcriptase inhibitor selection from ACTG A5142

OBJECTIVE

To compare the longitudinal changes in total bone mineral density (TBMD) across antiretroviral (ARV) regimens.

METHODS

A5142 was an open-label study comparing 3 ARV regimens for the initial treatment of HIV-1. Subjects were randomized equally to efavirenz (EFV) plus 2 nucleoside reverse transcriptase inhibitors (NRTIs), lopinavir/ritonavir (LPV/r) plus 2 NRTIs, or LPV/r plus EFV without NRTI. The NRTI regimen (lamivudine [3TC] plus zidovudine [ZDV], stavudine [d4T], or tenofovir [TDF]) was selected prior to randomization. TBMD was assessed via whole-body dual-energy X-ray absorptiometry (DXA) at baseline and 48 and 96 weeks. Analysis was modified intent-to-treat (ITT) ignoring regimen changes using all evaluations.

RESULTS

Significant mean declines in TBMD at week 48 were observed among subjects. In repeated-measures analysis of changes (including randomized regimen, NRTI used, and time), there was a significant difference in the NRTI-containing arms in mean percentage change in TBMD at week 48 according to NRTI used (P < .001). Subjects taking ZDV had similar changes to those taking d4T (P = .970), whereas those taking TDF had larger declines (P < .001). There was a nonsignificant trend toward greater mean declines among subjects taking LPV/r versus EFV (P = .080). Overall, TDF-containing regimens demonstrated the greatest losses in TBMD, while EFV regimens without TDF had lesser TBMD reductions even compared to the NRTI-sparing arm. From week 48 to 96, all treatment groups continued to lose TBMD at similar rates.

CONCLUSIONS

Among NRTI-containing arms, NRTI selection, especially use of TDF, had a greater effect on TBMD change than randomized regimen. The long-term clinical significance remains to be demonstrated.

Impact of antiretroviral therapy on bone metabolism markers in HIV-seropositive patients

OBJECTIVE

To evaluate the impact of antiretroviral therapy (ART) on bone and mineral metabolism and to determine the occurrence of osteopenia and/or osteoporosis in HIV-infected patients taking ART or not.

METHODS

A cross-sectional study was conducted on 50 HIV-seropositive adult men treated with or not treated with ART. Dual energy X-ray absorptiometry (DXA) was performed and biochemical analyses of the following markers were carried out: FSH, LH, testosterone, total calcium, phosphorus (Pi), magnesium (Mg), albumin, 24h calcium, creatinine, urea, parathormone (PTH), insulin-like growth factor 1 (IGF-I), 25 hydroxyvitamin D (25-OH-D), osteocalcin, and urinary deoxypyridinoline (DPD). The participants were divided into two groups according to ART use or not: Group A, 10 treatment-naive subjects; Group B, ART use for >2years, subdivided into: Group B1, 10 subjects treated with protease inhibitors (PIs) and nucleoside/nucleotide analog reverse transcriptase inhibitors (NRTIs) and Group B2, 10 subjects treated with NRTIs and non-nucleoside analog reverse transcriptase inhibitors (NNRTIs); and Group C, subjects treated with ART <2years, subdivided into: Group C1, 10 subjects treated with PIs and NRTIs and Group C2, 10 subjects treated with NRTIs and NNRTIs.

RESULTS

The values of the bone formation marker, osteocalcin, were normal in all groups, whereas urinary DPD values were increased in all groups. Whole body DXA revealed a higher percentage of osteopenia (80%) in Group B2. Lumbar spine DXA showed osteoporosis in Groups A and B1 (10%) and total femur DXA in Group B2 (10%).

CONCLUSION

The increased bone reabsorption marker indicated a high reabsorptive activity of bone tissue. These data indicate a greater osteoclastic activity in bone loss in HIV-infected patients on ART.

Changes in bone mineral density over a 2-year period in HIV-1-infected men under combined antiretroviral therapy with osteopenia

OBJECTIVE

Although osteopenia is common in HIV-infected patients, there is by now limited data on the evolution of bone mineral density in this population. We aimed to evaluate the course of osteopenia over a 2-year period in HIV-1-infected men, and to identify risk factors for abnormal bone mineral density (BMD) decline.

METHODS

HIV-1-infected men on combined antiretroviral therapy (cART) screened in the ANRS 120 Fosivir trial, diagnosed with low BMD (-2.5 ≤T-score <-1), not receiving antiosteoporotic agents, with sequential dual-energy-X ray-absorptiometry (DXA) available at baseline were eligible for this study and had a second DXA performed between months 24 and 36.

RESULTS

We enrolled 94 men with a median age of 46 years [interquartile range (IQR), 41-53], BMI 22 kg/m² (21-25) and a CD4 cell nadir of 164/μl (69-261). They were receiving cART for a median of 7.5 years (5.8-9.5). Over a median interval of 2.6 years (2.3-2.9) between the two DXA tests, the mean change in BMD was -0.5 ± 1.7% per year (P = 0.010) at the lumbar spine and -0.4 ± 1.8% per year (P = 0.033) at the hip. BMD fell by more than the smallest detectable difference (SDD) in, respectively, 25.5 and 27.7% of patients at the lumbar spine and hip. Tenofovir (TDF) exposure was independently associated with a larger decline in BMD at both sites [lumbar spine, OR = 2.4 (1.2-4.9); hip, OR = 2.8 (1.3-5.9)].

CONCLUSION

Although osteopenia overall modestly changes over 2 years in long-term cART-treated patients, a quarter of patients experienced a significant loss (>1 SDD) associated with TDF exposure.

Evaluation of bone alterations in the jaws of HIV-infected menopausal women

The advent of highly active antiretroviral therapy (HAART) has caused a reduction in mortality, thus contributing to an increase in the number of women with HIVࢧAIDS who reach the climacteric period, experience decline in ovarian function, and develop complications of viral infection and HAART, which can accelerate bone loss. The aim of this study was to detect possible alterations in the jaws of HIV-infected women by panoramic radiography. The study comprised a total of 120 women above 40 years of age who were divided into the following two groups: women who are HIV positive (Group I) and women with no known HIV infection (Group II). Measurement of the following three radiomorphometric indexes was performed by panoramic radiography: Mental Index (MI), Panoramic Mandibular Index (PMI) and Antegonial Depth (AD). A total of 70% of women in the control group and 50% of women in the HIV group were in the postmenopausal period, and the average values of both MI (p = 0.0054) and AD (p < 0.0001) for this period were lower in the HIV group than in the control group. For patients who were in the premenopausal period, the average AD was lower in the HIV group than in the control group (p = 0.0003). Despite the difference in the average age between groups, greater bone resorption in the mandible was found in the group of HIV-positive women.

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.

Fractures after antiretroviral initiation

BACKGROUND

Bone mineral density declines by 2-6% within 1-2 years after initiation of antiretroviral therapy (ART); however, it is uncertain whether this results in an immediate or cumulative increase in fracture rates.

METHODS

We evaluated the incidence and predictors of fracture in 4640 HIV-positive participants from 26 randomized ART studies followed in the AIDS Clinical Trials Group (ACTG) Longitudinal-Linked Randomized Trial study for a median of 5 years. Fragility and nonfragility fractures were recorded prospectively at semiannual visits. Incidence was calculated as fractures/total person-years. Cox proportional hazards models evaluated effects of traditional fracture risks, HIV disease characteristics, and ART exposure on fracture incidence.

RESULTS

Median (interquartile range) age was 39 (33, 45) years; 83% were men, 48% white, and median nadir CD4 cell count was 187 (65, 308) cells/μl. Overall, 116 fractures were reported in 106 participants with median time-to-first fracture of 2.3 years. Fracture incidence was 0.40 of 100 person-years among all participants and 0.38 of 100 person-years among 3398 participants who were ART naive at enrollment into ACTG parent studies. Among ART-naive participants, fracture rates were higher within the first 2 years after ART initiation (0.53/100 person-years) than subsequent years (0.30/100 person-years). In a multivariate analysis of ART-naive participants, increased hazard of fracture was associated with current smoking and glucocorticoid use but not with exposure to specific antiretrovirals.

CONCLUSION

Fracture rates were higher within the first 2 years after ART initiation, relative to subsequent years. However, continuation of ART was not associated with increasing fracture rates in these relatively young HIV-positive individuals.

Vitamin D status in young HIV infected women of various ethnic origins: incidence of vitamin D deficiency and possible impact on bone density

BACKGROUND

Decreased bone mineral density (BMD) was reported in HIV infected patients. Mechanisms leading to this decrease are poorly understood.

AIMS

To assess factors relating to BMD in young HIV infected Israeli women of Ethiopian and Caucasian origin.

PATIENTS AND METHODS

75 young HIV infected women aged 34.5 ± 8.5 followed up at the Institute of Allergy, Clinical Immunology & AIDS filled a questionnaire about sun exposure, daily calcium intake and dress habits. Data about HIV status and treatment regimens were collected from the patients' charts. Serum hydroxyvitamin D [25(OH)D] levels, bone turnover markers and bone densitometry were evaluated.

RESULTS

28 (65%) of Ethiopians and 2 (6.25%) of Caucasians had 25(OH)D serum levels <10 ng/ml (vitamin D deficiency), p = 0.001. 21 (67.7%) Ethiopians and 16 (39%) Caucasians avoided sun exposure, p = 0.019. Mean daily calcium intake was 491 ± 268.6 mg and 279 ± 252.6 mg, respectively, p = 0.001. Z scores < -1 found at Lumbar spine in 26 (89.7%), at Femoral neck in 20 (69%) at Total hip in 17 (58.6%) of vitamin D deficient patients compared to 20 (48.8%), 17 (41.5%), 9 (22%), in patients with 25(OH)D > 10 ng/ml, p < 0.01, <0.03, <0.001, respectively. Significantly more Ethiopian than Caucasian women covered their face (32.3% and 9.5%, p = 0.003) and hands (58.1% and 30.9%, p = 0.03). There was no difference in bone turnover markers levels.

CONCLUSION

Poorer vitamin D status was observed in Ethiopian women might be one of the important factors related to lower BMD in this group.

Antiretroviral therapy in Indian setting: when & what to start with, when & what to switch to?

With the rapid scale up of antiretroviral therapy, there is a dramatic decline in HIV related morbidity and mortality in both developed and developing countries. Several new safe antiretroviral, and newer class of drugs and monitoring assays are developed recently. As a result the treatment guideline for the management of HIV disease continue to change. This review focuses on evolving science on Indian policy - antiretroviral therapy initiation, which drugs to start with, when to change the initial regimen and what to change.

Prospective evaluation of bone markers, parathormone and 1,25-(OH)₂ vitamin D in HIV-positive patients after the initiation of tenofovir/emtricitabine with atazanavir/ritonavir or efavirenz

BACKGROUND

Increased risk of fractures and osteoporosis have been associated with the use of antiretroviral drugs. There is a paucity of prospective evaluations of bone markers after the initiation of drugs currently recommended to treat HIV infection and results on the evolution of these markers are conflicting. Lastly, the effect of tenofovir on 1,25-(OH)₂ vitamin D is uncertain.

METHODS

We performed a prospective study on the evolution of bone markers, parathormone and 1,25-(OH)₂ vitamin D before and after standard antiretroviral regimens. This was a sub-study of a trial conducted in antiretroviral-naïve patients randomized to tenofovir + emtricitabine in combination with either atazanavir/ritonavir (ATV/r) or efavirenz (EFV). Follow-up lasted 48 weeks. The following bone markers were analyzed: C-terminal cross-laps (CTx), osteocalcin (OC), osteoprotegerin (OPG), and receptor activator of nuclear factor κB ligand (RANKL). Mixed-factorial analysis of variance with random-coefficient general linear model was used to compare their trends over time and linear multivariable regression was performed with a backward selection method to assess predictors of their variations from baseline to week 48. Trends of parathormone and 1,25-(OH)₂ vitamin D were also evaluated.

RESULTS

Seventy-five patients were studied: 33 received EFV and 42 ATV/r. Significant increases were found for all markers except for RANKL. There was a significant direct association between CTx and OC increases. Multivariable analysis showed that higher glomerular filtration rate (estimated through cystatin C clearance) predicted greater OPG increase, while older age, higher HIV RNA at baseline and use of ATV/r predicted greater CTx increase. A significant increase of parathormone accompanied the evolution of the study markers. 1,25-(OH)₂ vitamin D remained stable, though a seasonality variation was demonstrated.

CONCLUSIONS

These data demonstrate CTx increase (bone resorption marker) corresponding to OC increase (bone formation marker) early upon HAART initiation. Moreover, predictors of bone marker increases have been suggested, possibly indicating that a stricter monitoring of bone health and pro-active interventions are needed in older patients, those with higher HIV RNA, prescribed ATV/r rather than EFV, and with decreased renal function at baseline. Further studies are needed to clarify the mechanisms responsible for up-regulation of bone turnover markers, as well as to understand if and what markers are best correlated or predictive of pathological fractures.

Low bone mass prevalence, therapy type, and clinical risk factors in an HIV-infected Brazilian population

Low bone mineral density (BMD) has been described in human immunodeficiency virus (HIV)-infected patients, but data on associated factors are still unclear, and to our knowledge, no reports are available in Brazil. Our goal was to evaluate BMD in HIV patients attending an outpatient clinic in Vitoria, Brazil. A sectional study was performed in 300 HIV-infected patients to measure BMD by dual-energy X-ray absorptiometry (DXA). Age, gender, anthropometric parameters, nadir and current CD4 cell count, HIV viral load, smoking habit, and current antiretroviral therapy (ART) associations were investigated by multivariable analysis. Based on World Health Organization T-score ranges, low BMD (T-score <-1.0 standard deviation [SD] in postmenopausal women and men aged 50 and older or Z-score <- 2.0 SD in premenopausal women and men below the age of 50) was detected in 54.7% (95% confidence interval: 49.1-60.3%) of the 300 enrolled patients. The observed median age was 46 yr (interquartile range: 39-52), 58% were male, 88.5% were on ART, and 21.4% smoked. The following factors were identified, by multiple logistic modeling, as being independently associated with low BMD: (1) male gender (4.6 [1.28-16.39]), (2) body mass index lower than 25 kg/m(2) (2.9 [1.31-6.49]), (3) menopause (13.4 [2.53-71.12]), and (4) HIV-1 undetectable viral load (7.9 [1.96-32.25]). Conversely, zidovudine (0.2 [0.04-0.85]) and nevirapine (0.1 [0.02-0.38]) use were inversely associated with low BMD. Low BMD was frequently found in our cohort of about 300 Brazilian HIV-infected subjects. This study supports the need for periodic DXA testing in HIV outpatient clinics.

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.

Effects of HIV infection and antiretroviral therapy with ritonavir on induction of osteoclast-like cells in postmenopausal women

SUMMARY

Ritonavir (RTV) is a commonly used antiretroviral associated with bone loss. We show that peripheral blood mononuclear cells (PBMCs) from human immunodeficiency virus (HIV)-positive women on RTV are more likely to differentiate into osteoclast-like cells when cultured with their own sera than PBMCs and sera from HIV- women or HIV+ on other antiretrovirals.

INTRODUCTION

RTV increases differentiation of human adherent PBMCs to functional osteoclasts in vitro, and antiretroviral regimens containing RTV have been associated with low bone mineral density (BMD) and bone loss.

METHODS

BMD, proresorptive cytokines, bone turnover markers (BTMs), and induction of osteoclast-like cells from adherent PBMCs incubated either with macrophage colony-stimulating factor (MCSF) and receptor activator of nuclear factor κB ligand (RANKL) or with autologous serum were compared in 51 HIV- and 68 HIV+ postmenopausal women.

RESULTS

BMD was lower, and serum proresorptive cytokines and BTMs were higher in HIV+ versus HIV- women. Differentiation of osteoclast-like cells from adherent PBMCs exposed to either MCSF/RANKL or autologous serum was greater in HIV+ women. Induction of osteoclast-like cells was greater from PBMCs exposed to autologous sera from HIV+ women on RTV-containing versus other regimens (172 ± 14% versus 110 ± 10%, p < 0.001). Serum-based induction of osteoclast-like cells from adherent PBMCs correlated with certain BTMs but not BMD.

CONCLUSIONS

HIV infection and antiretroviral therapy are associated with higher BTMs and increased differentiation of osteoclast-like cells from adherent PBMCs, especially in women on regimens containing RTV. HIV+ postmenopausal women receiving RTV may be at greater risk for bone loss.

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

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

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Decrease of vitamin D concentration in patients with HIV infection on a non nucleoside reverse transcriptase inhibitor-containing regimen

Background

Vitamin D is an important determinant of bone health and also plays a major role in the regulation of the immune system. Interestingly, vitamin D status before the start of highly active antiretroviral therapy (HAART) has been recently associated with HIV disease progression and overall mortality in HIV-positive pregnant women. We prospectively studied vitamin D status in HIV individuals on HAART in Belgium.

We selected samples from HIV-positive adults starting HAART with a pre-HAART CD4 T-cell count >100 cells/mm³ followed up for at least 12 months without a treatment change. We compared 25-hydroxyvitamin D plasma [25-(OH)D] concentration in paired samples before and after 12 months of HAART. 25-(OH)D levels are presented using two different cut-offs: <20 ng/ml and <30 ng/ml.

Results

Vitamin D deficiency was common before HAART, the frequency of plasma 25-(OH)D concentrations below 20 ng/ml and 30 below ng/ml was 43.7% and 70.1% respectively. After 12 months on HAART, the frequency increased to 47.1% and 81.6%.

HAART for 12 months was associated with a significant decrease of plasma 25-(OH)D concentration (p = 0.001). Decreasing plasma 25-(OH)D concentration on HAART was associated in the multivariate model with NNRTI-based regimen (p = 0.001) and lower body weight (p = 0.008). Plasma 25-(OH)D concentrations decreased significantly in both nevirapine and efavirenz-containing regimens but not in PI-treated patients.

Conclusions

Vitamin D deficiency is frequent in HIV-positive individuals and NNRTI therapy further decreases 25-(OH)D concentrations. Consequently, vitamin D status need to be checked regularly in all HIV-infected patients and vitamin D supplementation should be given when needed.

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.

Antiretroviral therapy and bone mineral measurements in HIV-infected youths

Reduced bone mass measurements are often found in HIV-infected youths. Both in vitro and human studies demonstrated a role of antiretroviral treatment in determining bone mass alteration. Nevertheless, the data regarding the responsibility of different antiretroviral drugs on bone health in children and adolescents are highly controversial. The purpose of the current study was to relate antiretroviral treatment to bone mass measurements in a large cohort of HIV-infected children and adolescents. Bone mineral content (BMC) was measured in 86 HIV-infected youths (aged 4.8-22.1 years), and in 194 healthy controls (aged 4.9-21.9 years). Fifteen patients were naive to antiretroviral treatment, 11 were receiving a dual nucleoside reverse transcriptase inhibitor (NRTIs) combination, 32 a protease inhibitor (PI)-based antiretroviral treatment, and 28 a non-nucleoside reverse transcriptase inhibitor (NNRTIs)-based regimen. Comparisons between healthy and HIV-infected children and adolescents have been performed by multiple regression analyses to correct for differences in age, sex, and anthropometric measurements. Patients receiving a PI-based treatment had lumbar spine and whole body BMC values significantly lower than healthy children (P<0.05). BMC measurements of patients on other therapeutic regimens or naive to antiretroviral treatment did not differ significantly from those of healthy children. Among patients receiving a PI-based regimen, those receiving full dose Ritonavir had significantly lower lumbar spine BMC values compared to other patients. Lumbar spine and whole body BMC measurements of patients receiving a Stavudine-containing regimen were lower compared to healthy controls, naive patients, and patients on other antiretroviral regimens. Multivariate analyses showed that patients receiving both Stavudine and full dose Ritonavir had significantly lower BMC values both at the lumbar spine (P=0.0033), and in the whole skeleton (P=0.05). In conclusion, antiretroviral treatment may have a detrimental effect on bone health of HIV-infected youths: the use of Ritonavir full dose alone or in combination with Stavudine is associated to lower bone mass measurements. The use of antiretroviral regimens including these drugs should thus be monitored closely in HIV-infected youths.

Antiretroviral medications: adverse effects on the kidney

The widespread introduction of highly active antiretroviral therapy (HAART) in the mid-1990s dramatically altered the course of human immunodeficiency virus (HIV) infection, with improvements in survival and reductions in the incidence of AIDS-defining illnesses. Although antiretroviral therapy has been shown to reduce the incidence of both AIDS-defining and non-AIDS conditions, long-term exposure to HAART may also be associated with significant toxicity. This article reviews the potential nephrotoxicity of specific antiretroviral agents and the impact of antiretroviral therapy on related metabolic disorders. The antiretroviral agents most strongly associated with direct nephrotoxicity include the nucleotide reverse transcriptase inhibitor, tenofovir, and the protease inhibitor indinavir, although other agents have been implicated less frequently. Tenofovir and related nucleotide analogs have primarily been associated with proximal tubular dysfunction and acute kidney injury, whereas indinavir is known to cause nephrolithiasis, obstructive nephropathy, and interstitial nephritis. Kidney damage related to antiretroviral therapy is typically reversible with early recognition and timely discontinuation of the offending agent, and nephrologists should be familiar with the potential toxicity of these agents to avoid delays in diagnosis.

Loss of bone mineral density after antiretroviral therapy initiation, independent of antiretroviral regimen

BACKGROUND

Decreased bone mineral density (BMD) has been described in HIV-infected patients initiating antiretroviral therapy (ART), but the contributions of ART and immunologic and/or virologic factors remain unclear.

METHODS

We compared total BMD changes over 96 weeks in 106 ART-naive HIV-infected subjects who were randomized to receive efavirenz (EFV) + zidovudine/lamivudine (n = 32) or lopinavir/ritonavir (LPV/r) + zidovudine/lamivudine induction (n = 74) for 24-48 weeks followed by LPV/r monotherapy. We also sought to identify factors associated with BMD loss, including markers of systemic inflammation [soluble tumor necrosis factor-alpha receptors (sTNFR I and II)].

RESULTS

After 96 weeks, the mean percent change from baseline in total BMD was -2.5% (LPV/r) and -2.3% (EFV) (P < 0.01 for within-group changes in either arm; P = 0.86 for between-group differences). No alteration in the rate of BMD change was observed upon simplification to LPV/r monotherapy. Although soluble tumor necrosis factor-alpha receptor II concentrations at baseline and 24 weeks were at least marginally associated with subsequent changes in BMD (P = 0.06 and P = 0.028, respectively), these associations were no longer significant after adjustment for CD4 T cell count. Subjects with lower baseline CD4 T cell count, non-black race, and higher baseline glucose demonstrated a higher risk for >5% decrease in BMD.

CONCLUSIONS

Similar decreases in BMD over 96 weeks occurred in ART-naive subjects receiving either EFV-based regimen or LPV/r-based regimen, which was not altered by simplification to LPV/r monotherapy and was unrelated to markers of tumor necrosis factor-alpha activity.

Continuous antiretroviral therapy decreases bone mineral density

OBJECTIVES

To assess the effects of antiretroviral therapy (ART) on bone mineral density (BMD) DESIGN: Randomized comparison of continuous ART (viral suppression group; VS) with intermittent ART (drug conservation group; DC) SETTING: Outpatient clinics in the United States, Australia, and Spain.

PARTICIPANTS

Participants in the Strategies for Management of Antiretroviral Therapy (SMART) Body Composition substudy.

MAIN OUTCOME MEASURES

Annual hip and spine BMD by dual-energy radiographic absorptiometry (DXA) and spine BMD by quantitative computed tomography (qCT).

METHODS

Comparisons were by intention-to-treat analysis, using longitudinal models for change in BMD. Risk factors for BMD loss were evaluated.

RESULTS

The 214 participants (median 44 years, 19% female participants, 73% on ART; median T-scores -0.5 total hip, -0.7 spine DXA, -0.9 spine qCT; 98 randomized to VS and 116 to DC) were followed for a mean 2.4 years. With continuous ART, BMD declined per year by 0.8% (hip), 0.4% (spine DXA), and 2.4% (spine qCT). BMD declined significantly less with intermittent ART. Estimated DC minus VS group differences in mean BMD change through follow-up were 1.4% [hip; 95% confidence interval (CI) 0.6-2.3; P = 0.002], 1.3% (spine DXA; 95% CI 0.1-2.4, P = 0.03), and 3.0% (spine qCT; 95% CI 0.8-5.2, P = 0.007). No consistent drug-specific association with BMD decline was found. In the parent study, 10 of 2753 participants in the VS group and two of 2720 in the DC group reported serious fractures (hazard ratio 4.9; 95% CI 1.1-22.5; P = 0.04).

CONCLUSION

Continuous ART is associated with decline in BMD and possibly more fractures relative to intermittent, CD4 cell count-guided ART.

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

OBJECTIVE

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

DESIGN

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

METHODS

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

RESULTS

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

CONCLUSION

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

Greater decrease in bone mineral density with protease inhibitor regimens compared with nonnucleoside reverse transcriptase inhibitor regimens in HIV-1 infected naive patients

OBJECTIVE

To evaluate the change in bone mineral density (BMD) at specific sites in patients initiating antiretroviral therapy in a substudy of the ANRS 121 trial.

METHODS

Antiretroviral-naive patients were randomized (2: 1: 1) into three treatment strategy arms: a nonnucleoside reverse transcriptase inhibitor (NNRTI) and a boosted protease inhibitor (PI/r), a PI/r and two nucleoside reverse transcriptase inhibitors (NRTIs) or an NNRTI and NRTIs. Hip and lumbar spine standardized BMD were evaluated at baseline and week 48 by dual X-ray absorptiometry by a central reading laboratory.

RESULTS

Seventy-one patients were enrolled: 36 in the PI/r and NNRTI, 19 in the PI/r and NRTIs and 16 in the NNRTI and NRTIs arms. Baseline characteristics were [median (interquartile range)]: male (77%), age 40 years (33-49), 69% white, 58% smokers, BMI 23 kg/m2 (21-24), CD4 cell count 219 cells/microl (144-285). In the arms with NRTIs, 86% of patients received zidovudine/lamivudine. At baseline, 31% had osteopenia and 3% had osteoporosis. At week 48, there was a mean change in BMD of -4.1 +/- 3.9% at lumbar spine and -2.8 +/- 4.7% at hip (both P< or = 0.001). The decrease of BMD at lumbar spine was significantly worse in the PI/r and NNRTI arm (-4.4 +/- 3.4%) and in the PI/r and NRTIs arm (-5.8 +/- 4.5%) compared with the NNRTI and NRTIs arm (-1.5 +/- 2.9%), P = 0.007 and P = 0.001, respectively.

CONCLUSION

BMD was impaired in 34% of patients, before starting any antiretrovirals. After 1 year, the decrease in lumbar spine BMD was more pronounced in patients receiving either PI/r-containing regimen compared with NNRTI and NRTIs. BMD at specific sites should be monitored during lifelong antiretroviral therapy.

Is vitamin D deficiency involved in the immune reconstitution inflammatory syndrome?

Background

About 20–30% of persons with HIV infection, especially those living in countries with limited resources, experience an immune reconstitution inflammatory syndrome (IRIS) after starting antiretroviral treatment. The active form of vitamin D, 1,25-dihydroxyvitamin D, is a key player in the clearance of pathogens and influences the level of inflammation and macrophage activation.

Presentation of the hypothesis

We hypothesize that low availability of 1,25-dihydroxyvitamin D, either due to vitamin D deficiency or due to polymorphisms in the vitamin D receptor or in its activating/inactivating enzymes, contributes to the appearance of IRIS. Furthermore, drug interactions with the enzymatic pathways of vitamin D could favour the development of IRIS.

Testing the hypothesis

Our hypothesis could be explored by a case-control study to assess the prevalence of vitamin D deficiency in HIV-infected patients on antiretroviral treatment who develop and do not develop IRIS.

Implications of the hypothesis

If the role of vitamin D in IRIS is confirmed, we would be able to screen patients at risk for IRIS by screening for vitamin D deficiency. After confirmation by means of a clinical trial, vitamin D supplementation could be a cheap and safe way to reduce the incidence of IRIS.

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.

WNT/beta-catenin signaling is involved in regulation of osteoclast differentiation by human immunodeficiency virus protease inhibitor ritonavir: relationship to human immunodeficiency virus-linked bone mineral loss

Untreated human immunodeficiency virus (HIV) infection is accompanied by reduced bone mineral density, which appears to be exacerbated by certain HIV protease inhibitors (PIs). The mechanisms leading to this apparent paradox, however, remain unclear. We have previously shown that, the HIV envelope glycoprotein gp120 used at levels similar those in plasmas of untreated HIV(+) patients, induced expression of the osteoclast (OC) differentiation factor RANKL in CD4+ T cells. In addition, the HIV PI ritonavir abrogated the interferon-gamma-mediated degradation of the RANKL nuclear adapter protein TRAF6, a physiological block to RANKL activity. Here, using oligonucleotide microarrays and quantitative polymerase chain reaction, we explored potential upstream mechanisms for these effects. Ritonavir, but not the HIV PIs indinavir or nelfinavir, up-regulated the production of transcripts for OC growth factors and the non-canonical Wnt Proteins 5B and 7B as well as activated promoters of nuclear factor-kappaB signaling, but suppressed genes involved in canonical Wnt signaling. Similarly, ritonavir blocked the cytoplasmic to nuclear translocation of beta-catenin, the molecular node of the Wnt signaling pathway, in association with enhanced beta-catenin ubiquitination. Exposure of OC precursors to LiCl, an inhibitor of the canonical Wnt antagonist GSK-3beta, suppressed OC differentiation, as did adenovirus-mediated overexpression of beta-catenin. These data identify, for the first time, a biologically relevant role for Wnt signaling via beta-catenin in isolated OC precursors and the modulation of Wnt signaling by ritonavir. The reversal of these ritonavir-mediated changes by interferon-gamma provides a model for possible intervention in this metabolic complication of HIV therapy.

Key Data from the 10th International Workshop on Adverse Drug Reactions and Lipodystrophy in HIV, 6–8 November 2008, London, UK

Although the list of clinical complications associated with HIV therapy continues to grow, the underlying mechanisms remain incompletely understood. Metabolic abnormalities, such as dyslipidaemia, insulin resistance and cardiovascular disease continue to top the list, but there is an increasing appreciation of the effect of HIV and anti-retroviral therapy on body composition, bone metabolism, muscle function and autonomic nervous system control of lipid and glucose metabolism. The 10th International Workshop on Adverse Drug Reactions and Lipodystrophy in HIV brought together physicians and researchers in the area of HIV management with world experts involved in adipose tissue metabolism and lipid regulation, bone and muscle metabolism and renin- angiotensin and blood pressure control to review and discuss recent findings in these areas. The data presented at the meeting highlight that studies of adipose tissue remain a major focus of attempts to unravel the pathophysiology that accompany lipodystrophy associated with HIV infection and/ or its therapy. There is also a growing appreciation and understanding of the direct role of HIV in the development of various comorbidities, including bone disease, cardiac dysfunction and neuropathologies, including peripheral neuropathy. Two key emerging themes were those of mitochondrial dysfunction and a heightened basal inflammatory state, exemplified by increased levels of proinflammatory cytokines, chemokines and markers such as C-reactive protein. These might prove to be the common denominators that link HIV-associated pathologies with diverse organ systems.

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.