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

Bone health and HIV in resource-limited settings: a scoping review

PURPOSE OF REVIEW

Sub-Saharan Africa and other resource-limited settings (RLS) bear the greatest burden of the HIV epidemic globally. Advantageously, the expanding access to antiretroviral therapy (ART) has resulted in increased survival of HIV individuals in the last 2 decades. Data from resource rich settings provide evidence of increased risk of comorbid conditions such as osteoporosis and fragility fractures among HIV-infected populations. We provide the first review of published and presented data synthesizing the current state of knowledge on bone health and HIV in RLS.

RECENT FINDINGS

With few exceptions, we found a high prevalence of low bone mineral density (BMD) and hypovitaminosis D among HIV-infected populations in both RLS and resource rich settings. Although most recognized risk factors for bone loss are similar across settings, in certain RLS there is a high prevalence of both non-HIV-specific risk factors and HIV-specific risk factors, including advanced HIV disease and widespread use of ART, including tenofovir disoproxil fumarate, a non-BMD sparing ART. Of great concern, we neither found published data on the effect of tenofovir disoproxil fumarate initiation on BMD, nor any data on incidence and prevalence of fractures among HIV-infected populations in RLS.

SUMMARY

To date, the prevalence and squeal of metabolic bone diseases in RLS are poorly described. This review highlights important gaps in our knowledge about HIV-associated bone health comorbidities in RLS. This creates an urgent need for targeted research that can inform HIV care and management guidelines in RLS.

The Association of Gender, Age, Efavirenz Use, and Hypovitaminosis D Among HIV-Infected Adults Living in the Tropics

Vitamin D, which is important for calcium homeostasis and bone metabolism, has several noncalcemic actions. Low vitamin D levels have been observed in HIV-infected patients from high latitudes, with consequently reduced bone mineral density (BMD), but data from the tropics are scarce. We aimed to determine the prevalence of and risk factors for hypovitaminosis D among HIV-infected patients in the tropics. This was a cross-sectional study to determine serum 25-hydroxyvitamin D [25(OH)D] levels in HIV-infected patients who attended our HIV clinic in Bangkok, Thailand from July 2010 to June 2011. Hypovitaminosis D was defined as vitamin D insufficiency and deficiency [25(OH)D 20-30 ng/ml and <20 ng/ml, respectively]. Hypovitaminosis D prevalence was calculated and risk factors were determined using multivariate logistic regression. A total of 673 HIV-infected adults were included. The median age was 41 years and 47% were females. The median body mass index (BMI) was 21.9 kg/m(2) and 93% were using antiretroviral therapy (ART), with a median (IQR) duration of 8.9 (5.0-10.4) years. Thirty-one percent were using efavirenz (EFV). The prevalence of vitamin D insufficiency and deficiency was 40.6% and 29.9%, respectively. In multivariate analysis, female gender [odds ratio: OR (95% confidence interval: 95% CI) 1.7 (1.2-2.3), p = 0.005], age >37 years [OR (95% CI) 1.6 (1.1-2.4), p = 0.01], and EFV use [OR (95% CI) 2.0 (1.3-3.2), p = 0.004] were independent predictors of hypovitaminosis D. Even in tropical areas where the sun is abundant, hypovitaminosis D is highly prevalent. Thus, treatment of low vitamin D in HIV-infected patients at high risk should not be ignored to prevent reductions in BMD and other hypovitaminosis D-related comorbidities.

Improvement of BMD after Switching from Lopinavir/R Plus Two Nucleos(T)ide Reverse Transcriptase Inhibitors to Lopinavir/R Plus Lamivudine: OLE-LIP Substudy

OBJECTIVE

To compare 48-week changes in bone mineral density (BMD) and body fat distribution between patients continuing lopinavir/ritonavir and two NRTIs and those switching to lopinavir/ritonavir and lamivudine.

METHODS

Substudy of a randomized, open-label, multicenter OLE study was carried out. Adult HIV-infected patients with <50 copies/mL for ≥6 months were randomized (1:1) to continue lopinavir/ritonavir and two NRTIs or switching to lopinavir/ritonavir and lamivudine. Dual-energy X-ray absorptiometry (DXA) was performed at baseline and after 48 weeks to measure bone composition and body fat distribution in both the groups.

RESULTS

Forty-one patients (dual-therapy, n = 23; triple-therapy, n = 18) of 239, who received at least one dose of study medication, completed the study: median age, 42 years, 71% male, 73% Caucasian. At week 48, total BMD increased by 1.04% (95% CI, 0.06 to 2.01%) among patients switching to dual-therapy, whereas no significant changes occurred in patients maintaining triple-therapy. Dual-therapy and older age were independently associated with total BMD increase. Among patients discontinuing tenofovir-DF, a significant increase was seen in total BMD (1.43; 95% CI, -0.04 to 2.91) and total hip (1.33%; 95% CI, 0.44 to 2.22%). A non-statistically significant decrease in femoral and spinal BMD was observed in patients who discontinued abacavir and in those continuing triple-therapy. Regarding fat distribution, no significant changes were seen in both the treatment groups.

DISCUSSION

BMD increased following switching to lopinavir/ritonavir plus lamivudine in HIV-infected patients on suppressive triple-therapy with lopinavir/ritonavir and two NRTIs including tenofovir-DF.

Antiretroviral therapy induces a rapid increase in bone resorption that is positively associated with the magnitude of immune reconstitution in HIV infection

OBJECTIVE

Antiretroviral therapy (ART) paradoxically intensifies bone loss in the setting of HIV infection. Although the extent of bone loss varies, it occurs with virtually all ART types, suggesting a common pathway that may be aligned with HIV disease reversal. Using an animal model of immunodeficiency we recently demonstrated that immune activation associated with CD4 T-cell reconstitution induces increased production of the osteoclastogenic cytokines RANKL and TNFα by immune cells, driving enhanced bone resorption and loss in bone mineral density.

DESIGN

To confirm these findings in humans, we investigated the early kinetics of CD4 T-cell recovery in relation to biomarkers of bone turnover and osteoclastogenic regulators in a prospective 24-week cohort study.

METHODS

Clinical data and blood sampling for HIV-RNA PCR, CD4 T-cell counts, bone turnover biomarkers, and osteoclastogenic regulators were obtained from ART-naïve HIV-infected study participants initiating standard doses of lopinavir/ritonavir plus tenofovir disoproxil fumarate/emtricitabine at baseline and at weeks 2, 8, 12, and 24 post ART.

RESULTS

C-terminal telopeptide of collagen (CTx) a sensitive biomarker of bone resorption rose by 200% above baseline at week 12, remaining elevated through week 24 (α<0.01), and was associated with significant increases in plasma levels of osteoclastogenic regulators [receptor activator of NF-kB ligand (RANKL), tumor necrosis factor alpha, (TNFα)]. Importantly, the magnitude of CD4 T-cell recovery correlated significantly with CTx (rs = 0.387, α=0.01).

CONCLUSION

Our data suggest that ART-induced bone loss occurs early, is aligned with early events of immune reconstitution, and these immune changes provide a unifying mechanism to explain in part the skeletal decline common to all ART.

Perspectives on menopause and women with HIV

Since the implementation of effective combination antiretroviral therapy, HIV infection has been transformed from a life-threatening condition into a chronic disease. As people with HIV are living longer, aging and its associated manifestations have become key priorities as part of HIV care. For women with HIV, menopause is an important part of aging to consider. Women currently represent more than one half of HIV-positive individuals worldwide. Given the vast proportion of women living with HIV who are, and will be, transitioning through age-related life events, the interaction between HIV infection and menopause must be addressed by clinicians and researchers. Menopause is a major clinical event that is universally experienced by women, but affects each individual woman uniquely. This transitional time in women's lives has various clinical implications including physical and psychological symptoms, and accelerated development and progression of other age-related comorbidities, particularly cardiovascular disease, neurocognitive dysfunction, and bone mineral disease; all of which are potentially heightened by HIV or its treatment. Furthermore, within the context of HIV, there are the additional considerations of HIV acquisition and transmission risk, progression of infection, changes in antiretroviral pharmacokinetics, response, and toxicities. These menopausal manifestations and complications must be managed concurrently with HIV, while keeping in mind the potential influence of menopause on the prognosis of HIV infection itself. This results in additional complexity for clinicians caring for women living with HIV, and highlights the shifting paradigm in HIV care that must accompany this aging and evolving population.

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.

Antiretroviral Therapy, Especially Efavirenz, Is Associated with Low Bone Mineral Density in HIV-Infected South Africans

Purpose

We determined the prevalence and correlates of low bone mineral density (BMD) in HIV-infected South Africans as there is a paucity of such data from Africa.

Methods

BMD and serum 25-hydroxyvitamin D were measured in HIV-positive participants on antiretroviral therapy (ART) and in those not yet on ART (ART-naïve).

Results

We enrolled 444 participants [median age 35(IQR: 30, 40) years; 77% women]. BMD was low (z score <-2SD) in 17% and 5% of participants at the lumbar spine and total hip, respectively. Total hip [0.909 (SD 0.123) vs 0.956 (SD 0.124) g/cm², p = 0.0001] and neck of femur BMD [0.796 (SD 0.130) vs 0.844 (SD 0.120) g/cm², p = 0.0001] were lower in the ART, compared to the ART-naïve group. Vitamin D deficiency was present in 15% of participants and was associated with efavirenz use [adjusted OR 2.04 (95% CI 1.01 to 4.13)]. In a multivariate linear regression, exposure to efavirenz or lopinavir-based ART was associated with lower total hip BMD, whereas higher weight, being male and higher vitamin D concentration were associated with higher total hip BMD (adjusted R² = 0.28). Age, weight, sex, and the use of efavirenz-based ART were independently associated with lumbar spine BMD (adjusted R² = 0.13).

Conclusions

Vitamin D status, use of efavirenz or lopinavir/ritonavir, weight, age and sex are significantly associated with lower BMD in this young cohort of HIV-infected South Africans.

Bone loss in HIV: a contemporary review

PURPOSE OF REVIEW

Because of antiretroviral therapy (ART), people are living with HIV infection longer than ever before. As this patient group ages, it is expected that medical comorbidities such as osteoporosis and fragility fractures will increase. The purpose of this review is to address the epidemiology and what is known regarding the pathogenesis of bone loss in people living with HIV infection with a focus on recently published literature.

RECENT FINDINGS

HIV-infected individuals are at increased risk for low bone mineral density and bone fractures. The cause of bone loss in HIV is multifactorial including traditional risk factors some of which disproportionately affect HIV-infected individuals and alterations in bone metabolism due to ART, HIV viral proteins and chronic inflammation. Lifestyle modification, changing ART, calcium and vitamin D supplementation and pharmacologic treatment for osteoporosis may all be employed to abrogate bone loss in this patient group.

SUMMARY

Clinicians should be aware of the contributors to bone loss in people living with HIV in order to recognize high-risk individuals and to take appropriate steps to address modifiable risk factors to prevent future fracture.

Greater change in bone turnover markers for efavirenz/emtricitabine/tenofovir disoproxil fumarate versus dolutegravir + abacavir/lamivudine in antiretroviral therapy-naive adults over 144 weeks

OBJECTIVE

Antiretroviral therapy initiation has been linked to bone mineral density and bone biomarker changes. We assessed long-term bone turnover biomarker effects over 144 weeks in patients initiating dolutegravir (DTG) + abacavir/lamivudine (ABC/3TC) versus efavirenz/emtricitabine/tenofovir disoproxil fumarate (EFV/FTC/TDF).

METHODS

Patients randomized in SINGLE received DTG (50 mg once daily) + ABC/3TC or fixed-dose combination EFV/FTC/TDF. We evaluated vitamin D serum levels and bone turnover markers (BTMs), including type 1 collagen cross-linked C-telopeptide (CTx), osteocalcin, bone-specific alkaline phosphatase (BSAP), and procollagen type 1 N-terminal propeptide (P1NP), at baseline and weeks 48, 96, and 144.

RESULTS

Among the 833 enrolled patients (68% white, 85% men), baseline median age was 35 years (range 18-85), median CD4 was 338 cells/μl, and median BMI was 24 kg/m. Fifty-three percent of patients smoked, and 6% reported baseline vitamin D use, with no meaningful differences between groups. Relative to baseline, CTx, osteocalcin, BSAP, and P1NP increased; vitamin D decreased in both groups at weeks 48, 96, and 144. Changes from baseline typically peaked at weeks 48 or 96 and for the four analytes, excluding vitamin D, with the EFV/FTC/TDF group having significantly greater changes from baseline at all time points.

CONCLUSION

DTG + ABC/3TC in antiretroviral therapy-naive patients resulted in significantly lower increases in BTMs (CTx, osteocalcin, BSAP, P1NP) compared with EFV/FTC/TDF over 144 weeks. The observed changes are consistent with results from other smaller, randomized trials. These differences in BTMs likely correlate with changes in bone mineral density over time.

Bone Disease in HIV: Recommendations for Screening and Management in the Older Patient

Availability of potent antiretroviral therapy (ART) has resulted in markedly improved survival for people with human immunodeficiency virus (HIV) infection, as well as an aging HIV population. Increasing morbidity from age-related conditions has resulted in the need to understand the complex roles HIV and its treatment play in the pathogenesis of these conditions. Bone disease and fragility fractures are conditions that occur more frequently in HIV. It is therefore recommended that risk assessment for fragility fracture using the Fracture Risk Assessment Tool (FRAX(®)) algorithm, and low bone mass by dual energy X-ray absorptiometry (DXA) scan, be performed in all patients with HIV infection over the age of 50 years and in those with a history of fragility fracture, and should be repeated every 2-3 years. Because many HIV experts believe that HIV infection and its treatment is a secondary cause of osteoporosis, it should be included as such in the FRAX(®) assessment tool. Management of osteoporosis in HIV infection should follow the same guidelines as that in the general population. Attention to lifestyle factors, including vitamin D replacement, should be emphasized. Whether cessation of tenofovir- or protease inhibitor-based ART regimens should be considered prior to bisphosphonate treatment is currently unknown and should only occur in patients with active alternative ART regimens. The use of bisphosphonates has been shown to be safe and effective in HIV patients, and while there is limited data on second-line osteoporosis regimens, there is no reason to suggest they would not be effective in people with HIV.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Bone mineral density and inflammatory and bone biomarkers after darunavir-ritonavir combined with either raltegravir or tenofovir-emtricitabine in antiretroviral-naive adults with HIV-1: a substudy of the NEAT001/ANRS143 randomised trial

BACKGROUND

Osteopenia, osteoporosis, and low bone mineral density are frequent in patients with HIV. We assessed the 96 week loss of bone mineral density associated with a nucleoside or nucleotide reverse transcriptase inhibitor (NtRTI)-sparing regimen.

METHODS

Antiretroviral-naive adults with HIV were enrolled in 78 clinical sites in 15 European countries into a randomised (1:1), open-label, non-inferiority trial (NEAT001/ANRS143) assessing the efficacy and safety of darunavir (800 mg once per day) and ritonavir (100 mg once per day) plus either raltegravir (400 mg twice per day; NtRTI-sparing regimen) or tenofovir (245 mg once per day) and emtricitabine (200 mg once per day; standard regimen). For this bone-health substudy, 20 of the original sites in six countries participated, and any patient enrolled at one of these sites who met the following criteria was eligible: plasma viral loads greater than 1000 HIV RNA copies per mL and CD4 cell counts of fewer than 500 cells per μL, except in those with symptomatic HIV infection. Exclusion criteria included treatment for malignant disease, testing positive for hepatitis B virus surface antigen, pregnancy, creatinine clearance less than 60 mL per min, treatment for osteoporosis, systemic steroids, or oestrogen-replacement therapy. The two primary endpoints were the mean percentage changes in lumbar spine and total hip bone mineral density at week 48, assessed by dual energy x-ray absorptiometry (DXA) scans. We did the analysis with an intention-to-treat-exposed approach with antiretroviral modifications ignored. The parent trial is registered with ClinicalTrials.gov, number NCT01066962, and is closed to new participants.

FINDINGS

Between Aug 2, 2010, and April 18, 2011, we recruited 146 patients to the substudy, 70 assigned to the NtRTI-sparing regimen and 76 to the standard regimen. DXA data were available for 129, 121 and 107 patients at baseline, 48 and 96 weeks respectively. At week 48, the mean percentage loss in bone mineral density in the lumbar spine was greater in the standard group than in the NtRTI-sparing group (mean percentage change -2.49% vs -1.00%, mean percentage difference -1.49, 95% CI -2.94 to -0.04; p=0.046). Total hip bone mineral density loss was similarly greater at week 48 in the standard group than in the NtRTI-sparing group (mean percentage change -3.30% vs -0.73%; mean percentage difference -2.57, 95% CI -3.75 to -1.35; p<0.0001). Seven new fractures occurred during the trial (two in the NtRTI-sparing group and five in the standard group).

INTERPRETATION

A raltegravir-based regimen was associated with significantly less loss of bone mineral density than a standard regimen containing tenofovir disoproxil fumarate, and might be a treatment option for patients at high risk of osteopenia or osteoporosis who are not suitable for NtRTIs such as abacavir or tenofovir alafenamide.

FUNDING

The European Union Sixth Framework Programme, Inserm-ANRS, Ministerio de Sanidad y Asuntos Sociales de España, Gilead Sciences, Janssen Pharmaceuticals, and Merck Laboratories.

Role of T-cell reconstitution in HIV-1 antiretroviral therapy-induced bone loss

HIV infection causes bone loss. We previously reported that immunosuppression-mediated B-cell production of receptor activator of NF-κB ligand (RANKL) coupled with decline in osteoprotegerin correlate with decreased bone mineral density (BMD) in untreated HIV infection. Paradoxically, antiretroviral therapy (ART) worsens bone loss although existing data suggest that such loss is largely independent of specific antiretroviral regimen. This led us to hypothesize that skeletal deterioration following HIV disease reversal with ART may be related to T-cell repopulation and/or immune reconstitution. Here we transplant T cells into immunocompromised mice to mimic ART-induced T-cell expansion. T-cell reconstitution elicits RANKL and TNFα production by B cells and/or T cells, accompanied by enhanced bone resorption and BMD loss. Reconstitution of TNFα- or RANKL-null T-cells and pharmacological TNFα antagonist all protect cortical, but not trabecular bone, revealing complex effects of T-cell reconstitution on bone turnover. These findings suggest T-cell repopulation and/or immune reconstitution as putative mechanisms for bone loss following ART initiation.

Lower Newborn Bone Mineral Content Associated With Maternal Use of Tenofovir Disoproxil Fumarate During Pregnancy

BACKGROUND

Fetal bone effects of maternal tenofovir use have not been well studied. We sought to compare whole-body bone mineral content (BMC) of newborns exposed vs not exposed to tenofovir in utero.

METHODS

We enrolled participants from April 2011 to June 2013 at 14 US clinical sites. Singleton infants of women with human immunodeficiency virus (HIV) infection who took tenofovir in late pregnancy (tenofovir-exposed) or no tenofovir during pregnancy (tenofovir-unexposed) were enrolled during late pregnancy or within 72 hours of birth. Infants born before 36 weeks gestation or with confirmed HIV infection were excluded. Whole-body BMC was measured in the first month of life and compared with that of the tenofovir-exposed and tenofovir-unexposed newborns, unadjusted and adjusted for covariates.

RESULTS

Seventy-four tenofovir-exposed and 69 tenofovir-unexposed infants had evaluable BMC measurements. Tenofovir-exposed mothers were more likely to be married (31% vs 22%; P = .04) and to use boosted protease inhibitors (84% vs 62%; P = .004). Tenofovir-exposed newborns did not differ from unexposed newborns on mean gestational age (38.2 vs 38.1 weeks) or mean length (-0.41 vs -0.18) or weight (-0.71 vs -0.48) Z-scores. The mean (standard deviation) BMC of tenofovir-exposed infants was 12% lower than for unexposed infants (56.0 [11.8] vs 63.8 [16.6] g; P = .002). The adjusted mean bone mineral content was 5.3 g lower (95% confidence interval, -9.5, -1.2; P = .013) in the tenofovir-exposed infants.

CONCLUSIONS

Maternal tenofovir use is associated with significantly lower neonatal BMC. The duration and clinical significance of this finding should be evaluated in longitudinal studies.

CLINICAL TRIALS REGISTRATION

ClinicalTrials.gov NCT01310023.

Effects of raltegravir combined with tenofovir/emtricitabine on body shape, bone density, and lipids in African-Americans initiating HIV therapy

BACKGROUND

Raltegravir (RAL) plus tenofovir/emtricitabine (TDF/FTC) is a recommended initial antiretroviral regimen. A substantial proportion of persons diagnosed with HIV infection and starting antiretrovirals in the U.S. are African-American (AA); however, the effects of this regimen on metabolic parameters have largely been studied in white patients.

METHODS

Single-arm, open-label study of untreated AA HIV-infected patients administered RAL with TDF/FTC for 104 weeks. Changes in fasting lipids, insulin resistance, visceral adipose tissue (VAT), abdominal subcutaneous adipose tissue (SAT), limb and trunk fat, and bone mineral density (BMD) were assessed at weeks 56 and 104.

RESULTS

Thirty (85% men) participants were included. Median entry characteristics included age of 38 years, CD4 323 cells/mm3, HIV RNA level 29,245 copies/ml, and body mass index 28.1 kg/m2. At 56 and 104 weeks, significant increases in VAT, trunk fat, limb fat, and overall fat were observed. Bone mineral density decreased by 1.5% by week 104.There were no significant changes in non-HDL-cholesterol, fasting triglycerides, or insulin resistance. A median CD4 cell count increase of 318 cells/mm3 (IQR 179, 403; full range 40, 749) (P<0.001) was observed. Assuming missing=failure, 78 and 70% had HIV RNA levels<40 copies/ml at weeks 56 and 104, respectively. There were no treatment-related discontinuations and no new antiretroviral resistance mutations were detected.

CONCLUSIONS

In this cohort of AAs, initiation of RAL with TDF/FTC was associated with significant general increases in fat. Significant changes in lipids or insulin resistance were not observed and there was a small decline in BMD. Therapy was well tolerated and effective. These results are consistent with findings of studies of initial antiretroviral therapy in racially diverse cohorts and inform treatment selection for AA patients starting therapy for HIV infection.

Differential Reduction in Monocyte Activation and Vascular Inflammation With Integrase Inhibitor-Based Initial Antiretroviral Therapy Among HIV-Infected Individuals

BACKGROUND

Little is known about how different antiretrovirals effect inflammation and monocyte activation in human immunodeficiency virus (HIV) infection.

METHODS

We examined plasma specimens obtained during a randomized, double-blinded trial in antiretroviral therapy (ART)-naive HIV-infected adults which compared the efficacy of elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate (EVG/c/FTC/TDF) with that of efavirenz/emtricitabine/tenofovir disoproxil fumarate (EFV/FTC/TDF). From a random sample achieving an HIV type 1 RNA load of <50 copies/mL by week 48, changes over 24 and 48 weeks in levels of biomarkers of monocyte activation (soluble CD14 [sCD14] and soluble CD163 [sCD163]), systemic inflammation (soluble tumor necrosis factor α receptor I [sTNF-RI], interleukin 6 [IL-6], and high-sensitivity C-reactive protein [hsCRP]), and vascular inflammation (lipoprotein-associated phospholipase A2 [Lp-PLA2]) were compared. Multivariable linear regression was used.

RESULTS

A total of 200 participants were included. Significant differences favoring EVG/c/FTC/TDF were noted for changes in sCD14, hsCRP, and Lp-PLA2 levels. Factors independently associated with a larger decrease in the sCD14 level included random assignment to receive EVG/c/FTC/TDF, higher baseline sCD14 level, and larger decreases in hsCRP and sCD163 levels; factors associated with a larger Lp-PLA2 decrease included higher baseline Lp-PLA2 and IL-6 levels, smaller increases in total cholesterol and triglycerides levels, a larger decrease in the sCD14 level, and a smaller decrease in the sCD163 level.

CONCLUSIONS

EVG/c/FTC/TDF led to greater decreases in sCD14, hsCRP, and Lp-PLA2 levels, compared with EFV/FTC/TDF. Randomization group independently predicted the change in sCD14 level, and changes in monocyte activation independently predicted the change in Lp-PLA2 level. There appears to be a more favorable effect of the integrase inhibitor EVG over efavirenz on immune activation, which may affect vascular inflammation.

Racial differences in bone loss and relation to menopause among HIV-infected and uninfected women

OBJECTIVE

To characterize changes in bone mineral density (BMD) according to race among HIV-infected and uninfected women, and to evaluate the relationship between race and menopause-related bone loss.

METHODS

Dual X-ray absorptiometry measured BMD on study entry and a minimum of 18 months later in 246 HIV-infected and 219 HIV-uninfected women in the Menopause Study. Linear regression analyses determined percent annual BMD change at the total hip (TH), femoral neck (FN), and lumbar spine (LS) after adjusting for potential confounders. Race-stratified and HIV-infected subgroup analyses were performed.

RESULTS

At baseline, mean age was 45 years, 19% of women were postmenopausal. HIV-infected women were more likely to be black (58% vs. 38%), and had lower BMI and less cigarette exposure when compared to HIV-uninfected women. Women who were perimenopausal at baseline and postmenopausal at follow-up had the greatest TH bone loss (-1.68%/yr, p < .0001) followed by those postmenopausal throughout (-1.02%/yr, p = .007). We found a significant interaction between HIV status and race in multivariate analyses of BMD change at the FN and TH. In race-stratified analyses, HIV infection was associated with TH BMD loss in non-black women. Black women experienced greater menopause-associated decline in TH BMD compared with non-black women.

CONCLUSIONS

The association of HIV and BMD differs strikingly by race, as do the effects of the menopausal transition on bone. Determining the extent to which the effect of HIV on fracture risk varies by race will be crucial to identify HIV-infected women at greatest risk for osteoporotic fracture, particularly as they enter menopause.

The ASSURE study: HIV-1 suppression is maintained with bone and renal biomarker improvement 48 weeks after ritonavir discontinuation and randomized switch to abacavir/lamivudine + atazanavir

OBJECTIVES

HIV treatment guidelines endorse switching or simplification of antiretroviral therapy in therapy-experienced patients with suppressed viraemia; ritonavir discontinuation may also enhance tolerability and reduce long-term adverse events (AEs). This open-label, multicentre, noninferiority study enrolled HIV-1-infected, treatment-experienced adults with confirmed HIV-1 RNA ≤ 75 HIV-1 RNA copies/mL currently receiving tenofovir/emtricitabine + atazanavir/ritonavir (TDF/FTC + ATV/r) for ≥ 6 months with no reported history of virological failure.

METHODS

Participants were randomized 1:2 to continue current treatment or switch to abacavir/lamivudine + atazanavir (ABC/3TC + ATV). Endpoints included the proportion of participants with HIV-1 RNA < 50 copies/mL by time to loss of virological response (TLOVR), AEs, fasting lipids, and inflammatory, coagulation, bone and renal biomarkers.

RESULTS

After 48 weeks, 76% (152 of 199) of ABC/3TC + ATV-treated and 79% (77 of 97) of TDF/FTC + ATV/r-treated participants had HIV-1 RNA < 50 copies/mL (TLOVR; P = 0.564). Other efficacy analyses yielded similar results. Rates of new grade 2-4 AEs were 45% in both groups, but an excess of hyperbilirubinaemia made the rate of treatment-emergent grade 3-4 laboratory abnormalities higher with TDF/FTC + ATV/r (36%) compared with ABC/3TC + ATV (19%). Most fasting lipid levels remained stable over time; high-density lipoprotein (HDL) cholesterol increased modestly in ABC/3TC + ATV-treated participants. Bone and renal biomarkers improved significantly between baseline and week 48 in participants taking ABC/3TC + ATV and were stable in participants taking TDF/FTC + ATV/r. No significant changes occurred in any inflammatory or coagulation biomarker within or between treatment groups.

CONCLUSIONS

The ABC/3TC + ATV treatment-switch group had similar viral suppression rates up to 48 weeks to the TDF/FTC + ATV/r comparator group, with lower rates of moderate- to high-grade hyperbilirubinaemia and improvements in bone and renal biomarkers.

Clinically Indicated Corticosteroids Do Not Affect Bone Turnover During Immune Restoration of Severely Lymphopenic HIV-Infected Patients

Lymphopenia, corticosteroids, antiretroviral therapy (ART), and inflammation negatively impact bone turnover and decrease bone mineral density, but their combined effect has not been evaluated. We examined the association between corticosteroids on bone turnover markers in severely lymphopenic HIV-infected patients initiating ART. Levels of osteocalcin (bone formation marker) and C-terminal telopeptide (CTX; bone resorption marker) were measured at baseline, weeks 4, 12, and 48 of ART in individuals with severe lymphopenia and opportunistic infection (OI) who received (n=28) or did not receive corticosteroids (n=30) during the first year of ART, and in a control group with CD4 >200 (n=15). Wilcoxon tests were used to compare median values of variables between groups. Correlations between plasma interleukin (IL)-6 and tumor necrosis factor (TNF) levels with bone turnover marker levels were performed using Spearman's coefficient. Individuals given corticosteroids received a median of 21 days at a 35 mg prednisone-equivalent daily dose. Individuals with severe lymphopenia had lower osteocalcin levels at baseline and week 4 and higher CTX levels at ART initiation vs.

CONTROLS

Bone turnover markers did not differ in severely lymphopenic persons according to corticosteroid receipt. In those with severe lymphopenia, higher IL-6 was associated with higher CTX levels at ART initiation only. HIV-infected patients with severe lymphopenia and OI had lower levels of bone formation and higher levels of bone resorption than those initiating ART at higher CD4. Corticosteroid use, as prescribed during OI, was not associated with bone turnover. In contrast, higher markers of systemic inflammation prior to ART were associated with greater bone resorption.

Plasma Sclerostin in HIV-Infected Adults on Effective Antiretroviral Therapy

Sclerostin is linked to bone physiology and cardiovascular disease through the Wnt/β-catenin signaling pathway. The goal of this study was to determine if sclerostin is related to bone physiology and cardiovascular disease during antiretroviral treatment in HIV-infected persons. This was a cross-sectional analysis from study entry into the Stopping Atherosclerosis and Treating Unhealthy bone with RosuvastatiN in HIV (SATURN) trial, an ongoing randomized trial comparing rosuvastatin to placebo in HIV-infected adults on antiretroviral therapy. Plasma sclerostin was measured at study entry by ELISA from participants with available samples. Spearman correlation and multivariable linear regression were used to test relationships between sclerostin and bone density or bone turnover and cardiovascular disease. Among 139 HIV-infected participants (median age 46 years, CD4 lymphocyte count 614 cells/μl), the median plasma sclerostin level was 444.1 (IQR 330.3, 570.1) pg/ml. Correlations were detected between sclerostin and age (r=0.26), lumbar spine Z-score (r=0.31), RANKL (r=-0.21), carotid intima-media thickness (CIMT, r=0.19), and sVCAM-1 (r=0.27), p<0.05. No significant correlations were detected between sclerostin and current (r=0.006) or nadir CD4 count (r=0.11). While associations between sclerostin, lumbar spine Z-score, and sVCAM-1 were robust to covariate adjustment (p<0.01), association with CIMT was no longer significant (p=0.08). Our findings provide preliminary support for a relationship between sclerostin and bone mineral density in HIV-infected persons. The Wnt/β-catenin pathway should be investigated as a potential mechanism for loss of bone mineral density in treated HIV infection.

Less Bone Loss With Maraviroc- Versus Tenofovir-Containing Antiretroviral Therapy in the AIDS Clinical Trials Group A5303 Study

BACKGROUND

There is a need to prevent or minimize bone loss associated with antiretroviral treatment (ART) initiation. We compared maraviroc (MVC)- to tenofovir disoproxil fumarate (TDF)-containing ART.

METHODS

This was a double-blind, placebo-controlled trial. ART-naive subjects with human immunodeficiency virus type 1 RNA load (viral load [VL]) >1000 copies/mL and R5 tropism were randomized to MVC 150 mg or TDF 300 mg once daily (1:1), stratified by VL <100 000 or ≥100 000 copies/mL and age <30 or ≥30 years. All subjects received darunavir 800 mg, ritonavir 100 mg, and emtricitabine 200 mg daily. Dual-energy X-ray absorptiometry scanning was done at baseline and week 48. The primary endpoint was percentage change in total hip bone mineral density (BMD) from baseline to week 48 in the as-treated population.

RESULTS

We enrolled 262 subjects. A total of 259 subjects (130 MVC, 129 TDF) contributed to the analyses (91% male; median age, 33 years; 45% white, 30% black, 22% Hispanic). Baseline median VL was 4.5 log10 copies/mL and CD4 count was 390 cells/µL. The decline in hip BMD (n = 115 for MVC, n = 109 for TDF) at week 48 was less with MVC (median [Q1, Q3] of -1.51% [-2.93%, -0.11%] vs -2.40% [-4.30%, -1.32%] for TDF (P < .001). Lumbar spine BMD decline was also less with MVC (median -0.88% vs -2.35%; P < .001). Similar proportions of subjects in both arms achieved VL ≤50 copies/mL in as-treated and ITT analyses.

CONCLUSIONS

MVC was associated with less bone loss at the hip and lumbar spine compared with TDF. MVC may be an option to attenuate ART-associated bone loss.

CLINICAL TRIALS REGISTRATION

NCT01400412.

Tenofovir: What We Have Learnt After 7.5 Million Person-Years of Use

Tenofovir was licensed for use in patients with HIV in 2001 and since then has become a firmly established anti-retroviral in both guidelines and routine practice. Data have been presented from many pivotal studies—informing on its efficacy, use, and adverse features—and there are also over 7.5 million patient-years of experience to date. We explore the data on this nucleotide reverse transcriptase inhibitor in HIV presented since 2008—focusing on efficacy, side effects, and utility.

Changes in Bone Mineral Density After Initiation of Antiretroviral Treatment With Tenofovir Disoproxil Fumarate/Emtricitabine Plus Atazanavir/Ritonavir, Darunavir/Ritonavir, or Raltegravir

BACKGROUND

Specific antiretroviral therapy (ART) medications and the severity of human immunodeficiency virus (HIV) disease before treatment contribute to bone mineral density (BMD) loss after ART initiation.

METHODS

We compared the percentage change in BMD over 96 weeks in 328 HIV-infected, treatment-naive individuals randomized equally to tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) plus atazanavir/ritonavir (ATV/r), darunavir/ritonavir (DRV/r), or raltegravir (RAL). We also determined whether baseline levels of inflammation markers and immune activation were independently associated with BMD loss.

RESULTS

At week 96, the mean percentage changes from baseline in spine and hip BMDs were similar in the protease inhibitor (PI) arms (spine: -4.0% in the ATV/r group vs -3.6% in the DRV/r [P = .42]; hip: -3.9% in the ATV/r group vs -3.4% in the DRV/r group [P = .36]) but were greater in the combined PI arms than in the RAL arm (spine: -3.8% vs -1.8% [P < .001]; hip: -3.7% vs -2.4% [P = .005]). In multivariable analyses, higher baseline concentrations of high-sensitivity C-reactive protein, interleukin 6, and soluble CD14 were associated with greater total hip BMD loss, whereas markers of CD4(+) T-cell senescence and exhaustion (CD4(+)CD28(-)CD57(+)PD1(+)) and CD4(+) T-cell activation (CD4(+)CD38(+)HLA-DR(+)) were associated with lumbar spine BMD loss.

CONCLUSIONS

BMD losses 96 weeks after ART initiation were similar in magnitude among patients receiving PIs, ATV/r, or DRV/r but lowest among those receiving RAL. Inflammation and immune activation/senescence before ART initiation independently predicted subsequent BMD loss.

Effects of Emtricitabine/Tenofovir on Bone Mineral Density in HIV-Negative Persons in a Randomized, Double-Blind, Placebo-Controlled Trial

BACKGROUND

Daily preexposure prophylaxis (PrEP) with oral emtricitabine and tenofovir disoproxil fumarate (FTC/TDF) decreases the risk of human immunodeficiency virus (HIV) acquisition. Initiation of TDF decreases bone mineral density (BMD) in HIV-infected people. We report the effect of FTC/TDF on BMD in HIV-seronegative men who have sex with men and in transgender women.

METHODS

Dual-energy X-ray absorptiometry was performed at baseline and 24-week intervals in a substudy of iPrEx, a randomized, double-blind, placebo-controlled trial of FTC/TDF PrEP. Plasma and intracellular tenofovir concentrations were measured in participants randomized to FTC/TDF.

RESULTS

In 498 participants (247 FTC/TDF, 251 placebo), BMD in those randomized to FTC/TDF decreased modestly but statistically significantly by 24 weeks in the spine (net difference, -0.91% [95% confidence interval {CI}, -1.44% to -.38%]; P = .001) and hip (-0.61% [95% CI, -.96% to -.27%], P = .001). Changes within each subsequent 24-week interval were not statistically significant. Changes in BMD by week 24 correlated inversely with intracellular tenofovir diphosphate (TFV-DP), which was detected in 53% of those randomized to FTC/TDF. Net BMD loss by week 24 in participants with TFV-DP levels indicative of consistent dosing averaged -1.42% ± 29% and -0.85% ± 19% in the spine and hip, respectively (P < .001 vs placebo). Spine BMD tended to rebound following discontinuation of FTC/TDF. There were no differences in fractures (P = .62) or incidence of low BMD.

CONCLUSIONS

In HIV-uninfected persons, FTC/TDF PrEP was associated with small but statistically significant decreases in BMD by week 24 that inversely correlated with TFV-DP, with more stable BMD thereafter.

CLINICAL TRIALS REGISTRATION

NCT00458393.

Differential skeletal impact of tenofovir disoproxil fumarate in young versus old HIV-infected adults

BACKGROUND

Lower peak bone mass in early adulthood predicts subsequent fragility fractures. Antiretroviral toxicity could contribute to young HIV-infected individuals not achieving adequate peak bone mass.

OBJECTIVE

To determine if tenofovir disoproxil fumarate's (TDF) effect on bone mineral density (BMD) differs by age.

METHODS

We examined BMD data at the lumbar spine and hip from AIDS Clinical Trials Group (ACTG) A5224s and ASSERT and randomized treatment-naive studies comparing TDF/emtricitabine versus abacavir/lamivudine (with efavirenz or atazanavir/ritonavir). In this post hoc analysis, we defined the TDF effect as the difference between mean 48-week BMD per cent changes for lumbar spine and hip in individuals randomized to TDF versus abacavir. We used multivariable linear regression to compare the TDF effect in individuals younger and older than 30 years. If TDF effect by age did not differ significantly between studies, we pooled study populations. Otherwise, analyses were conducted separately within each study population.

RESULTS

Among 652 subjects, 21% were below age 30 years. The relationship between age and TDF effect significantly differed between A5224s and ASSERT (P = 0.008 for lumbar spine; P = 0.007 for hip). In A5224s, there was more bone loss with TDF at lumbar spine and hip in subjects under 30 years old versus in older subjects ( - 4.5% vs - 1.4%; P = 0.045; - 4.3% vs - 1.6%; P = 0.026, respectively). There was no significant evidence for this age-associated TDF effect in ASSERT.

CONCLUSIONS

There was heterogeneity in the observed effect of TDF on bone density in young adults compared to older adults, suggesting that further investigation is required to understand the impact of age on BMD decline with TDF.

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 alterations associated with HIV

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

HIV infection and osteoporosis

In the past two decades, the life expectancy of people living with HIV infection has increased significantly, and osteoporosis has emerged as a significant comorbidity. In addition to traditional risk factors for fracture, specific factors related to HIV infection are also likely to contribute, including antiretroviral therapy. The heterogeneity of the HIV-infected population in terms of age and ethnicity presents many challenges to the prevention and management of bone disease, and further studies are required to establish optimal approaches to risk assessment and treatment.

Skeletal health in adults with HIV infection

Concern has been raised that HIV infection, its treatment, or both adversely affect skeletal health. Cross-sectional studies show that bone mineral density (BMD) is 3-5% lower in patients infected with HIV than in uninfected controls, but patients with HIV infection are, on average, 5 kg lighter than uninfected people. After this weight difference is accounted for, BMD differences are smaller and not clinically relevant. Longitudinal studies show short-term BMD loss of 2-4% over 1-2 years when antiretroviral therapy is started, followed by longer periods of BMD increase or stability. Losses are greatest with treatment regimens that contain tenofovir. Patients infected with HIV have slightly higher fracture rates than controls, but the increased risk of fracture is substantially attenuated by adjustment for traditional risk factors for fracture. These reassuring findings suggest that management of skeletal health in HIV should follow guidelines for the general population. In general, effective antiretroviral treatment and avoidance of undernutrition are the two most important factors for maintenance of skeletal health in patients infected with HIV.

Bone health in HIV-infected children, adolescents and young adults: a systematic review

BACKGROUND

Children and adolescents, who either acquire HIV infection perinatally, from contaminated blood products or via sexual transmission early in life, have the greatest cumulative exposure to the negative direct and indirect effects of HIV infection and ART on bone, which may lead to increased lifetime risk for osteoporosis and fracture. We conducted a systematic review to evaluate the literature on bone health in children and adolescents with HIV.

METHODS

We performed a comprehensive search of the Medline, Scopus, and Cochrane Library databases (up to April 1, 2014) for studies that reported on bone imaging or bone fractures in HIV-infected children, adolescents, or young adults.

RESULTS

A total of 32 publications met our inclusion criteria. Seventeen studies were cross-sectional and 15 were longitudinal. The majority of studies were conducted in high-income countries, three in middle-income countries and none in low-income countries. Overall, the studies we reviewed indicate that measures of bone mass are reduced, with increased prevalence of low BMD in children and adolescents with HIV. However, the studies are highly variable with respect to comparison sources, measurement methods, adjustment techniques for body size or growth retardation, and highlighted risk factors, including aspects related to medication exposures as well as the effects of HIV infection per se.

CONCLUSION

HIV infection appears to be associated with decreased bone accrual throughout childhood and adolescence. Initial studies indicate that sub-optimal bone accrual may be persistent and result in reduced peak bone mass, an important determinant of future risk of osteoporosis and fracture. Important areas for future research include evaluation of bone mass, bone quality and fracture risk across the life course among those with early-life infection with HIV, particularly in resource-limited settings where the majority of children with HIV live.

Outcomes in older versus younger patients over 96 weeks in HIV-1- infected patients treated with rilpivirine or efavirenz in ECHO and THRIVE

Objectives:

Increasing life expectancy of HIV-1–infected patients raises interest in how trial results apply to older patients. This post-hoc analysis evaluated potential differences in efficacy and safety in older (≥50 years) versus younger (<50 years) patients in the ECHO and THRIVE trials over 96 weeks.

Methods:

HIV-infected, treatment-naÏve adults were randomized to receive rilpivirine (RPV) or efavirenz (EFV), plus a background regimen. Virologic response rates (FDA snapshot analysis; HIV-1 RNA <50 copies/mL) were assessed at Week 96. Total-body bone mineral density was evaluated at baseline and Week 96 by dual-energy X-ray absorptiometry scans. Serum concentrations of 25-hydroxy vitamin D (ECHO trial only) were also measured at baseline, Week 24 and Week 48.

Results:

1368 patients were treated. At Week 96, virologic response rates were similar between older (77%) and younger (76%) RPV-treated patients and numerically higher in older (84%) versus younger (76%) EFV-treated patients. No clinically relevant age-related differences were observed in immunologic responses. Small differences were noted in older versus younger patients in adverse events (higher rates of depression, insomnia, and rash in older EFV-treated patients), laboratory abnormalities (increased low-density lipoprotein cholesterol and hyperglycemia in older EFV-treated patients and increased amylase in older patients across treatments), bone mineral density (larger decreases in older patients across treatments), and progression to severe vitamin D deficiency (greater in older versus younger EFV-treated patients).

Conclusion:

Efficacy and safety outcomes were generally similar in older versus younger patients in the ECHO and THRIVE trials.

Microstructural alterations of trabecular and cortical bone in long-term HIV-infected elderly men on successful antiretroviral therapy

OBJECTIVE

Progress in antiretroviral therapy (ART) has resulted in an almost normal life expectancy for HIV-infected individuals, but an increased risk of fragility fractures has been identified. We investigated the influence of long-term HIV infection on successful ART on bone microstructure in elderly men.

DESIGN

A cross-sectional, case–control study.

METHODS

Dual-energy X-ray absorptiometry (DXA) and high-resolution peripheral quantitative computed tomography (HR-pQCT) were performed in 28 HIV-positive men between 60 and 70 years old on successful ART. Controls were 112 HIV-negative men matched for age 4 years and BMI (4 kg/ m²).

RESULTS

HIV-positive men (median CD4þ cell count, 589 cells/ml; BMI, 24.8 kg/m²) had a median duration of HIV infection of 18.2 years. Compared with HIV-negative men, they had a lower DXA-measured areal bone mineral density at total hip (3.2%, P¼0.050) and ultra-distal radius (8.4%, P¼0.001). At distal radius and tibia, we observed microstructural alterations with a lower total density (16%, P¼ 0.005 and 14.3%, P¼ 0.039), trabecular density (11.6%, P¼ 0.012 and 12.2%, P¼ 0.007) and cortical area (17.5%, P¼ 0.002 and 12.2%, P¼ 0.01). In addition, they had a lower trabecular number (P¼ 0.036), higher trabecular spacing (P¼ 0.027) and lower cortical thickness (19.9%; P¼ 0.008) at distal radius. beta-crosslaps (CTX) and vitamin D levels were higher than in controls. By multivariate analyses, HIV status, higher CTX levels, lower physical activity and estradiol levels were determinants of bone density and microstructure alterations.

CONCLUSION

HIV-infected elderly men on successful ART have trabecular and cortical bone microstructure alterations associated with higher bone resorption, despite adequate vitamin D supplementation.

HIV and metabolic, body, and bone disorders: what we know from low- and middle-income countries

Globally, the HIV epidemic is evolving. Life expectancy for HIV-infected individuals has been extended because of more effective and more widely available antiretroviral therapy. As a result, chronic noncommunicable diseases (NCDs) have become important comorbid conditions. In particular, HIV-infected persons are increasingly at risk of developing metabolic (diabetes, dyslipidemias), body composition (lipodystrophy, overweight/obesity) and bone mineral density abnormalities. We have summarized the published epidemiological and clinical literature regarding these HIV-NCD comorbidities in low- and middle-income countries (LMICs). We found important gaps in knowledge. Specifically, there are few studies that use standardized methods and metrics; consequently, prevalence or incidence data are not comparable. There are very little or no data regarding the effectiveness or cost-effectiveness of clinical monitoring or therapeutic interventions for metabolic disorders in HIV-infected individuals. Also, although NCDs continue to grow in the HIV-negative population of most LMICs, there are few data comparing the incidence of NCD comorbidities between HIV-infected and HIV-negative populations. To address these gaps, we describe potential research and capacity development priorities for the future.

Physical activity and health outcomes among HIV-infected men who have sex with men: a longitudinal mediational analysis

BACKGROUND

Low physical activity is associated with depression, which may, in turn, negatively impact antiretroviral therapy (ART) adherence among HIV-infected individuals; however, prior studies have not investigated the relationships between physical inactivity and ART non-adherence.

PURPOSE

The purpose of this study was to examine the association of physical inactivity, depression, ART non-adherence, and viral load in HIV-infected men who have sex with men.

METHODS

The sample (N = 860) was from a large, multicenter cohort of HIV-infected patients engaged in clinical care.

RESULTS

Across time, depression mediated the relationship between physical inactivity and ART non-adherence (γ = 0.075) and the relationship between physical inactivity and viral load (γ = 0.05). ART non-adherence mediated the relationship between depression and viral load (γ = 0.002) and the relationship between physical inactivity and viral load (γ = 0.009).

CONCLUSIONS

Low levels of physical activity predicted increased depression and poor ART adherence over time, which subsequently predicted higher viral load.

Osteoporosis and fracture risk associated with HIV infection and treatment

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

Oral pre-exposure prophylaxis (PrEP) for prevention of HIV in serodiscordant heterosexual couples in the United States: opportunities and challenges

Oral HIV pre-exposure prophylaxis (PrEP) is a promising new biomedical prevention approach in which HIV-negative individuals are provided with daily oral antiretroviral medication for the primary prevention of HIV-1. Several clinical trials have demonstrated efficacy of oral PrEP for HIV prevention among groups at high risk for HIV, with adherence closely associated with level of risk reduction. In the United States (US), three groups have been prioritized for initial implementation of PrEP-injection drug users, men who have sex with men at substantial risk for HIV, and HIV-negative partners within serodiscordant heterosexual couples. Numerous demonstration projects involving PrEP implementation among MSM are underway, but relatively little research has been devoted to study PrEP implementation in HIV-serodiscordant heterosexual couples in the US. Such couples face a unique set of challenges to PrEP implementation at the individual, couple, and provider level with regard to PrEP uptake and maintenance, adherence, safety and toxicity, clinical monitoring, and sexual risk behavior. Oral PrEP also provides new opportunities for serodiscordant couples and healthcare providers for primary prevention and reproductive health. This article provides a review of the critical issues, challenges, and opportunities involved in the implementation of oral PrEP among HIV-serodiscordant heterosexual couples in the US.

Improvement in bone mineral density after switching from tenofovir to abacavir in HIV-1-infected patients with low bone mineral density: two-centre randomized pilot study (OsteoTDF study)

BACKGROUND

Tenofovir has been associated with a decrease in bone mineral density (BMD). However, data on changes in BMD after discontinuing tenofovir are lacking.

METHODS

We performed a two-centre randomized pilot study in virologically suppressed HIV-infected patients receiving tenofovir with osteopenia/osteoporosis (OsteoTDF study, ClinicalTrials.gov number NCT 01153217). Fifty-four patients were randomly assigned to switch from tenofovir to abacavir (n = 26) or to continue with tenofovir (n = 28). Changes in lumbar and total hip BMD were evaluated at Week 48 from baseline.

RESULTS

Five patients discontinued the study (three from the tenofovir group and two from the abacavir group). No significant differences were detected between the groups at Week 48 (P = 0.229 for total hip and P = 0.312 for lumbar spine). However, hip BMD improved by 2.1% (95% CI -0.6 to 4.7) (P = 0.043) in the abacavir group and 0.7% (95% CI -0.9 to 2.4) (P = 0.372) in the tenofovir group. Lumbar spine BMD varied by -0.7% (95% CI -3.8 to 3.3) (P ≤ 0.001) in the abacavir group and -1.2% (95% CI -3.8 to 0.4) (P < 0.001) in the tenofovir group.

CONCLUSIONS

Switching from tenofovir to abacavir led to a slight improvement in femoral BMD although no differences were detected between groups. Larger studies are necessary before firm recommendations can be made on the discontinuation of tenofovir in patients with a low BMD.

Is bone loss linked to chronic inflammation in antiretroviral-naive HIV-infected adults? A 48-week matched cohort study

OBJECTIVE

Antiretroviral therapy (ART) has been implicated in bone loss in HIV. The role of inflammation and vitamin D is unclear and better investigated in ART-naive individuals.

DESIGN AND METHODS

This is a 48-week, prospective cohort study to compare baseline and change in hip and spine bone mineral density (BMD) measured by dual-energy X-ray absorptiometry in HIV-infected, ART-naive adults and healthy controls matched by age, sex, and race. We also studied associations between bone loss and inflammation markers and plasma 25-hydroxyvitamin D [25(OH)D] using logistic regression.

RESULTS

Forty-seven HIV-infected adults and 41 controls were included. Baseline 25(OH)D, BMD at total hip, trochanter, and spine, and prevalence of osteopenia and osteoporosis were similar between groups. In the HIV-infected group, total hip and trochanter, but not spine, BMD decreased over 48 weeks [hip -0.005 (-0.026-0.008) g/cm², P = 0.02 within group; trochanter -0.013 (-0.03-0.003), P < 0.01]. BMD did not change at any site within controls. The HIV-infected group was more likely to have bone loss at the trochanter (P = 0.03). This risk persisted after adjustment for age, sex, race, BMI, smoking, and hepatitis C (odds ratio 4, 95% confidence interval 1.2-15.8). In the HIV-infected group, higher interleukin-6 concentrations (P = 0.04) and Caucasian race (P < 0.01) were independently associated with progression to osteopenia or osteoporosis, but not 25(OH)D levels.

CONCLUSION

BMD at the total hip and trochanter sites decreased in the HIV-infected, ART-naive adults, but not controls, over this 48-week study. Higher serum interleukin-6 concentrations were associated with progression to osteopenia or osteoporosis status in the HIV-infected group.

The effects of untreated and treated HIV infection on bone disease

PURPOSE OF REVIEW

Low bone mineral density (BMD) is common in those with HIV, associated with higher bone turnover and a higher prevalence of fractures. This review explores low BMD in HIV, focusing on underlying mechanisms and relationships between low BMD and HIV infection, immune dysfunction, and antiretroviral therapy (ART).

RECENT FINDINGS

Greater reductions in BMD accompanying reductions in HIV viremia at initiation of first-line or second-line ART suggest an important role for immune- or viral-mediated mechanisms in its pathogenesis.

SUMMARY

As bone metabolism is part-regulated by T cells and B cells, we propose that earlier initiation of ART at higher CD4 T-cell counts may attenuate BMD loss by abrogating immune- and viral-mediated disturbances in bone metabolism that accompany ART initiation. Further pathogenesis-based research is required in this field, focusing on the complex interaction between virus, immune system, ART, and bone metabolism.

HIV infection, bone metabolism, and fractures

With the advent of high active antiretroviral therapy there was a significant improvement on HIV subjects survival. Thus, bone changes related to HIV became an important aspect of these individuals. HIV affects bone remodeling causing bone fragility. In addition, antiretroviral therapy may also negatively affect bone metabolism. Several studies describe an increased incidence of fractures in these patients when compared with controls without the disease. The European Society of AIDS (EACS), and other societies, have included guidance on management of osteoporosis in HIV-infected patients emphasizing the identification of patients with low bone mass. Supplementation of calcium and vitamin D and the use of alendronate in these individuals should be recommended on a case base.

Long-term use of protease inhibitors is associated with bone mineral density loss

HIV-infected patients are at high risk for bone mineral density (BMD) loss. The present study was designed to provide information on characteristics of BMD abnormalities in Japanese HIV-1-infected patients and risk factors involved in worsening of BMD. A total of 184 Japanese HIV-1-infected men were studied with a dual-energy X-ray absorptiometry scan (DXA) at the lumbar spine and femoral neck. Multivariate logistic regression models were used for comparison of the impact of risk factors on BMD loss. Osteopenia and osteoporosis were diagnosed in 46% and 10% of the patients at lumbar spine, and 54% and 12% at femoral neck, respectively. In logistic analysis, factors associated with low BMD at both lumbar spine and femoral neck were long-term treatment with a protease inhibitor (PI) [odds ratio (OR) 1.100 and 1.187 per 1 year increase of PI use; 95% confidence interval (CI) 1.003-1.207 and 1.043-1.351; p=0.042 and 0.009, respectively] and a low body mass index [OR: 0.938 and 0.852, CI 0.892-0.992 and 0.783-0.927; p=0.024 and <0.001, respectively]. Patients who discontinued PI had a significantly higher BMD than those who currently use PI at lumbar spine (t score -0.8 vs. -1.3, p=0.04) but not at femoral neck (-1.3 vs. -1.5, p=0.38). In HIV-infected Japanese patients, the duration of treatment with PI correlated significantly with BMD loss. Discontinuation of PI is a promising option in the treatment of BMD loss since it allows recovery of BMD, especially in the lumbar spine.

Simplification to abacavir/lamivudine + atazanavir maintains viral suppression and improves bone and renal biomarkers in ASSURE, a randomized, open label, non-inferiority trial

Objective

Simplification of antiretroviral therapy in patients with suppressed viremia may minimize long-term adverse effects. The study’s primary objective was to determine whether abacavir/lamivudine + atazanavir (ABC/3TC+ATV) was virologically non-inferior to tenofovir/emtricitabine + atazanavir/ritonavir (TDF/FTC+ATV/r) over 24 weeks in a population of virologically suppressed, HIV-1 infected patients.

Design

This open-label, multicenter, non-inferiority study enrolled antiretroviral experienced, HIV-infected adults currently receiving a regimen of TDF/FTC+ATV/r for ≥6 months with no history of virologic failure and whose HIV-1 RNA had been ≤75 copies/mL on 2 consecutive measurements including screening. Patients were randomized 1∶2 to continue current treatment or simplify to ABC/3TC+ATV.

Methods

The primary endpoint was the proportion of patients with HIV-RNA<50 copies/mL at Week 24 by the Time to Loss of Virologic Response (TLOVR) algorithm. Secondary endpoints included alternative measures of efficacy, adverse events (AEs), and fasting lipids. Exploratory endpoints included inflammatory, coagulation, bone, and renal biomarkers.

Results

After 24 weeks, ABC/3TC+ATV (n = 199) was non-inferior to TDF/FTC+ATV/r (n = 97) by both the primary analysis (87% in both groups) and all secondary efficacy analyses. Rates of grade 2–4 AEs were similar between the two groups (40% vs 37%, respectively), but an excess of hyperbilirubinemia made the rate of grade 3–4 laboratory abnormalities higher in the TDF/FTC+ATV/r group (30%) compared with the ABC/3TC+ATV group (13%). Lipid levels were stable except for HDL cholesterol, which increased significantly in the ABC/3TC+ATV group. Bone and renal biomarkers improved significantly between baseline and Week 24 in patients taking ABC/3TC+ATV, and the difference between groups was significant at Week 24. No significant changes occurred in any inflammatory or coagulation biomarker within or between treatment groups.

Conclusions

After 24 weeks, simplification to ABC/3TC+ATV from TDF/FTC+ATV/r maintained viral suppression was well-tolerated, and led to improvements in bone and renal biomarkers and HDL cholesterol.

Trial Registration

ClinicalTrials.gov NCT01102972

GlaxoSmithKline Clinical Study Register #113734

Relationships between inflammation, immune activation, and bone health among HIV-infected adults on stable antiretroviral therapy

BACKGROUND

The aim was to determine the association between bone health and inflammation, T-cell activation, and monocyte activation among HIV-infected persons on stable antiretroviral therapy.

METHODS

We performed a cross-sectional analysis of all the subjects enrolling in the Stopping Atherosclerosis and Treating Unhealthy bone with RosuvastatiN in HIV trial with available skeletal assessments by dual-energy x-ray absorptiometry, inflammation, and immune activation markers. Analyses used were Wilcoxon rank-sum tests, Spearman correlation coefficients, and linear regression.

RESULTS

One hundred forty-two subjects were included: 78% men, 69% African American, median age 46.3 years, CD4 count 604 cells per microliter, and 77% with undetectable HIV-1 RNA. Twenty-three percent had osteopenia/osteoporosis at the hip, and 21% had this at the lumbar spine. Soluble vascular cell adhesion molecule-1 was correlated with hip (r = -0.22) and spine (r = -0.23) bone mineral density (BMD), and bone turnover markers (r = 0.20-0.33; all P < 0.05). No significant correlations were observed between the BMD and T-cell activation (%CD38HLA-DR on CD4 or CD8 T cells), monocyte activation (CD14CD16, sCD14, and sCD163), or inflammatory markers [interleukin (IL)-6, tumor necrosis factor-α, highly sensitive C-reactive protein, D-dimer, receptor activator of NF-kB ligand, osteoprotegerin, soluble tumor necrosis factor-RI and II]. In regression models including traditional bone risk factors, hip BMD was associated with age, race, and body mass index; spine BMD was associated with race, family history of hip fracture, trunk fat, tenofovir, and HIV RNA; bone resorption (c-terminal collagen crosslinks) was associated with intracellular adhesion molecule-1 and trunk fat; bone formation (P1NP) was associated with soluble vascular cell adhesion molecule-1, trunk and limb fat (P ≤ 0.05).

CONCLUSIONS

Future studies should evaluate the longitudinal association of the adhesion molecules to further elucidate potential contributory mechanisms of bone loss among HIV-infected persons on stable antiretroviral therapy.

Prevalence of causes of secondary osteoporosis and contribution to lower bone mineral density in HIV-infected patients

SUMMARY

Eighty-one percent of human immunodeficiency virus (HIV)-infected patients had one or more of seven evaluated causes of secondary osteoporosis, and this rate increases with age. The type and number of causes were associated with a lower bone mineral density (BMD), and with an increased rate of osteopenia/osteoporosis, regardless of age and body mass index.

INTRODUCTION

The objective of this study was to determine whether factors of secondary osteoporosis were associated with lower BMD in HIV.

METHODS

This was a cross-sectional study of 285 HIV-infected patients (25 % females) evaluating the impact of seven different factors of reduced BMD: hyperthyroidism, diabetes, chronic viral hepatitis, chronic kidney disease (CKD), hypovitaminosis D, secondary hyperparathyroidism, and hypogonadism. Dual-energy X-ray absorptiometry scan of the femoral neck was obtained at the clinical visit.

RESULTS

Mean age was 45.7 years; osteopenia and osteoporosis were diagnosed in 38 and 6 %, respectively. Overall, 230 patients (81 %) had secondary factors; 107 (38 %) had only 1 cause, 94 (33 %) had 2, and 28 (10 %) had 3 or more, predominantly vitamin D deficiency in 61 %, hepatitis C virus coinfection in 45 %, and secondary hyperparathyroidism in 27 %. The number of secondary factors was closely related to a lower BMD, which is statistically significant for patients having ≥2 causes (0.77 vs 0.73 g/cm(2), p = 0.02). The rate of osteopenia ranged from 36 % without any cause to 57 % with three or more, osteoporosis from 0 to 19 %, and Z-score <-2 SD from 0 to 27 %, respectively. In a multivariate linear regression, adjusting by age, body mass index, and HIV-related factors, the number of secondary factors was independently associated with a lower BMD (ß coefficient -0.134; p = 0.02), mainly due to patients with hepatitis C virus (HCV) coinfection, secondary hyperparathyroidism, and CKD.

CONCLUSIONS

A high prevalence of secondary causes of osteoporosis is observed in HIV-infected patients, and its type and cumulative number determine a lower BMD, after adjusting by age and body mass index.

Osteoporosis in Human Immunodeficiency Virus Patients - An Emerging Clinical Concern

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