Antiretroviral Therapy Intensification for Neurocognitive Impairment in Human Immunodeficiency Virus.

BACKGROUND: Neurocognitive impairment (NCI) in people with HIV (PWH) on antiretroviral therapy (ART) is common and may result from persistent HIV replication in the central nervous system. METHODS: A5324 was a randomized, double-blind, placebo-controlled, 96-week trial of ART intensification with dolutegravir (DTG) + MVC, DTG + Placebo, or Dual - Placebo in PWH with plasma HIV RNA <50 copies/mL on ART and NCI. The primary outcome was the change on the normalized total z score (ie, the mean of individual NC test z scores) at week 48. RESULTS: Of 357 screened, 191 enrolled: 71% male, 51% Black race, 22% Hispanic ethnicity; mean age 52 years; mean CD4+ T-cells 681 cells/µL. Most (65%) had symptomatic HIV-associated NC disorder. Study drug was discontinued due to an adverse event in 15 (8%) and did not differ between arms (P = .17). Total z score, depressive symptoms, and daily functioning improved over time in all arms with no significant differences between them at week 48 or later. Adjusting for age, sex, race, study site, efavirenz use, or baseline z score did not alter the results. Body mass index modestly increased over 96 weeks (mean increase 0.32 kg/m2, P = .006) and did not differ between arms (P > .10). CONCLUSIONS: This is the largest, randomized, placebo-controlled trial of ART intensification for NCI in PWH. The findings do not support empiric ART intensification as a treatment for NCI in PWH on suppressive ART. They also do not support that DTG adversely affects cognition, mood, or weight.

Bone mineral density reductions after tenofovir disoproxil fumarate initiation and changes in phosphaturia: a secondary analysis of ACTG A5224s.

Background: It is unknown if the greater reductions in bone mineral density (BMD) associated with initiation of tenofovir disoproxil fumarate compared with abacavir in previously untreated HIV-infected participants in the ACTG A5224s clinical trial were associated with potentially worsening tenofovir-related phosphaturia. Methods: We correlated changes in BMD at the hip and spine with changes in phosphaturia [transtubular reabsorption of phosphorus (TRP) and tubular maximum phosphate reabsorption per glomerular filtration rate (TmP/GFR)] from entry through week 96 in those initiating tenofovir ( n = 134) versus abacavir ( n = 135) with efavirenz or atazanavir/ritonavir in A5224s. We also correlated changes in BMD with tenofovir AUC measured between weeks 4 and 24. Results: Changes in TRP and TmP/GFR through week 96 between the tenofovir and abacavir arms were not significantly different (both P ≥ 0.70) and did not differ with use of efavirenz versus atazanavir/ritonavir. There were no significant correlations between changes in either TRP or TmP/GFR and with either hip or spine BMD in the tenofovir arms. Tenofovir AUC was significantly correlated with changes in hip BMD, but not spine BMD, at week 24 ( r = -0.22, P = 0.028) and week 48 ( r = -0.26, P = 0.010), but not at week 96 ( r = -0.14, P = 0.18). Conclusions: Changes in phosphaturia were not different between the tenofovir and abacavir arms in A5224s. Changes in hip and spine BMD with tenofovir were not related to changes in phosphaturia. However, tenofovir exposure was weakly associated with changes in hip BMD through week 48.

Long-term Bone Mineral Density Changes in Antiretroviral-Treated HIV-Infected Individuals.

We compared adjusted bone mineral density (BMD) changes between human immunodeficiency virus (HIV)-infected individuals during the first approximately 7.5 years after antiretroviral therapy (ART) initiation and HIV-uninfected controls. HIV-infected individuals (n = 97) had significantly greater adjusted BMD decline than controls (n = 614) during the first 96 weeks of ART. Subsequently, the rate of BMD decline slowed in HIV-infected individuals but remained greater than the rate of decline in HIV-uninfected individuals at the lumbar spine but not at the hip. In HIV-infected individuals after 96 weeks, no HIV- or treatment-related characteristic was associated with BMD loss, but lower lean body mass was associated with greater BMD loss at both lumbar spine and hip.

Evaluation of cardiovascular biomarkers in a randomized trial of fosamprenavir/ritonavir vs. efavirenz with abacavir/lamivudine in underrepresented, antiretroviral-naïve, HIV-infected patients (SUPPORT): 96-week results.

BACKGROUND: Rates of cardiovascular disease are higher among HIV-infected patients as a result of the complex interplay between traditional risk factors, HIV-related inflammatory and immunologic changes, and effects of antiretroviral therapy (ART). This study prospectively evaluated changes in cardiovascular biomarkers in an underrepresented, racially diverse, HIV-1-infected population receiving abacavir/lamivudine as backbone therapy. METHODS: This 96-week, open-label, randomized, multicenter study compared once-daily fosamprenavir/ritonavir 1400/100 mg and efavirenz 600 mg, both with ABC/3TC 600 mg/300 mg, in antiretroviral-naïve, HLA-B*5701-negative adults without major resistance mutations to study drugs. We evaluated changes from baseline to weeks 4, 12, 24, 48, and 96 in interleukin-6 (IL-6), high-sensitivity C-reactive protein (hs-CRP), soluble vascular adhesion molecule-1 (sVCAM-1), d-dimer, plasminogen, and fibrinogen. Biomarker data were log-transformed before analysis, and changes from baseline were described using geometric mean ratios. RESULTS: This study enrolled 101 patients (51 receiving fosamprenavir/ritonavir; 50 receiving efavirenz): 32% female, 60% African American, and 38% Hispanic/Latino; 66% (67/101) completed 96 weeks on study. At week 96, levels of IL-6, sVCAM-1, d-dimer, fibrinogen, and plasminogen were lower than baseline in both treatment groups, and the decrease was statistically significant for sVCAM-1 (fosamprenavir/ritonavir and efavirenz), d-dimer (fosamprenavir/ritonavir and efavirenz), fibrinogen (efavirenz), and plasminogen (efavirenz). Values of hs-CRP varied over time in both groups, with a significant increase over baseline at Weeks 4 and 24 in the efavirenz group. At week 96, there was no difference between the groups in the percentage of patients with HIV-1 RNA <50 copies/mL (fosamprenavir/ritonavir 63%; efavirenz 66%) by ITT missing-equals-failure analysis. Treatment-related grade 2-4 adverse events were more common with efavirenz (32%) compared with fosamprenavir/ritonavir (20%), and median lipid concentrations increased in both groups over 96 weeks of treatment. CONCLUSIONS: In this study of underrepresented patients, treatment with abacavir/lamivudine combined with either fosamprenavir/ritonavir or efavirenz over 96 weeks, produced stable or declining biomarker levels except for hs-CRP, including significant and favorable decreases in thrombotic activity (reflected by d-dimer) and endothelial activation (reflected by sVCAM-1). Our study adds to the emerging data that some cardiovascular biomarkers are decreased with initiation of ART and control of HIV viremia. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT00727597.

Abacavir-lamivudine versus tenofovir-emtricitabine for initial HIV-1 therapy.

BACKGROUND: The use of fixed-dose combination nucleoside reverse-transcriptase inhibitors (NRTIs) with a nonnucleoside reverse-transcriptase inhibitor or a ritonavir-boosted protease inhibitor is recommended as initial therapy in patients with human immunodeficiency virus type 1 (HIV-1) infection, but which NRTI combination has greater efficacy and safety is not known. METHODS: In a randomized, blinded equivalence study involving 1858 eligible patients, we compared four once-daily antiretroviral regimens as initial therapy for HIV-1 infection: abacavir-lamivudine or tenofovir disoproxil fumarate (DF)-emtricitabine plus efavirenz or ritonavir-boosted atazanavir. The primary efficacy end point was the time from randomization to virologic failure (defined as a confirmed HIV-1 RNA level > or = 1000 copies per milliliter at or after 16 weeks and before 24 weeks, or > or = 200 copies per milliliter at or after 24 weeks). RESULTS: A scheduled interim review by an independent data and safety monitoring board showed significant differences in virologic efficacy, according to the NRTI combination, among patients with screening HIV-1 RNA levels of 100,000 copies per milliliter or more. At a median follow-up of 60 weeks, among the 797 patients with screening HIV-1 RNA levels of 100,000 copies per milliliter or more, the time to virologic failure was significantly shorter in the abacavir-lamivudine group than in the tenofovir DF-emtricitabine group (hazard ratio, 2.33; 95% confidence interval, 1.46 to 3.72; P<0.001), with 57 virologic failures (14%) in the abacavir-lamivudine group versus 26 (7%) in the tenofovir DF-emtricitabine group. The time to the first adverse event was also shorter in the abacavir-lamivudine group (P<0.001). There was no significant difference between the study groups in the change from the baseline CD4 cell count at week 48. CONCLUSIONS: In patients with screening HIV-1 RNA levels of 100,000 copies per milliliter or more, the times to virologic failure and the first adverse event were both significantly shorter in patients randomly assigned to abacavir-lamivudine than in those assigned to tenofovir DF-emtricitabine. (ClinicalTrials.gov number, NCT00118898.)

Bone mineral density and fractures in antiretroviral-naive persons randomized to receive abacavir-lamivudine or tenofovir disoproxil fumarate-emtricitabine along with efavirenz or atazanavir-ritonavir: Aids Clinical Trials Group A5224s, a substudy of ACTG A5202.

BACKGROUND: Long-term effects of abacavir (ABC)-lamivudine (3TC), compared with tenofovir (TDF)-emtricitabine (FTC) with efavirenz (EFV) or atazanavir plus ritonavir (ATV/r), on bone mineral density (BMD) have not been analyzed. METHODS: A5224s was a substudy of A5202, in which HIV-infected treatment-naive participants were randomized and blinded to receive ABC-3TC or TDF-FTC with open-label EFV or ATV/r. Primary bone end points included Dual-emission X-ray absorbtiometry (DXA)-measured percent changes in spine and hip BMD at week 96. Primary analyses were intent-to-treat. Statistical tests used the factorial design and included linear regression, 2-sample t, log-rank, and Fisher's exact tests. RESULTS: Two hundred sixty-nine persons randomized to 4 arms of ABC-3TC or TDF-FTC with EFV or ATV/r. At baseline, 85% were male, and 47% were white non-Hispanic; the median HIV-1 RNA load was 4.6 log(10) copies/mL, the median age was 38 years, the median weight was 76 kg, and the median CD4 cell count was 233 cells/µL. At week 96, the mean percentage changes from baseline in spine and hip BMD for ABC-3TC versus TDF-FTC were -1.3% and -3.3% (P = .004) and -2.6% and -4.0% (P = .024), respectively; and for EFV versus ATV/r were -1.7% and -3.1% (P = .035) and -3.1% and -3.4% (P = .61), respectively. Bone fracture was observed in 5.6% of participants. The probability of bone fractures and time to first fracture were not different across components. CONCLUSIONS: Compared with ABC-3TC, TDF-FTC-treated participants had significantly greater decreases in spine and hip BMD, whereas ATV/r led to more significant losses in spine, but not hip, BMD than EFV. Clinical Trials Registration. NCT00118898.

Abacavir/lamivudine versus tenofovir DF/emtricitabine as part of combination regimens for initial treatment of HIV: final results.

BACKGROUND: AIDS Clinical Trials Group A5202 compared blinded abacavir/lamivudine (ABC/3TC) to tenofovir DF/emtricitabine (TDF/FTC) with efavirenz (EFV) or atazanavir/ritonavir (ATV/r) in human immunodeficiency virus (HIV)-infected treatment-naive patients, stratified by screening HIV RNA (< or ≥ 10(5) copies/mL). Due to higher virologic failure with ABC/3TC in the high HIV RNA stratum, blinded treatment was stopped in this group, but study follow-up continued for all patients. METHODS: Primary endpoints were times to virologic failure, regimen modification, and safety event. RESULTS: In the low HIV RNA stratum, time to virologic failure was similar for ABC/3TC vs TDF/FTC with ATV/r (hazard ratio [HR] 1.25, 95% confidence interval [CI] 0.76, 2.05) or EFV (HR 1.23, 95% CI 0.77, 1.96), with significantly shorter times to regimen modification for ABC/3TC with EFV or ATV/r and to safety events with EFV. Prior to stopping blinded treatment in the high stratum, higher virologic failure rates were seen with ABC/3TC with EFV (HR 2.46, 95% CI 1.20, 5.05) or ATV/r (HR 2.22, 95% CI 1.19, 4.14). CONCLUSIONS: In the low HIV RNA stratum, times to virologic failure for ABC/3TC or TDF/FTC were not different with EFV or ATV/r. In the high stratum, virologic failure rate was significantly higher for ABC/3TC than for TDF/FTC when given with either EFV or ATV/r.

Peripheral and central fat changes in subjects randomized to abacavir-lamivudine or tenofovir-emtricitabine with atazanavir-ritonavir or efavirenz: ACTG Study A5224s.

BACKGROUND: We compare the effect of 4 different antiretroviral regimens on limb and visceral fat. METHODS: A5224s was a substudy of A5202, a trial of human immunodeficiency virus type 1 (HIV-1)-infected, treatment-naive subjects randomized to blinded abacavir-lamivudine (ABC-3TC) or tenofovir DF-emtricitabine (TDF-FTC) with open-label efavirenz (EFV) or atazanavir-ritonavir (ATV-r). The primary endpoint was the presence of lipoatrophy (≥ 10% loss of limb fat) at week 96 by intent-to-treat (ITT) analysis. Secondary endpoints included changes in limb and visceral fat. Statistical tests included linear regression, binomial, two-sample t test, and Fisher's exact test. RESULTS: A5224s enrolled 269 subjects; 85% were male, and 47% were white non-Hispanic. The subjects had a median baseline HIV-1 RNA level of 4.6 log(10) copies/mL, a median age of 38 years, a median CD4+ cell count of 233 cells/µL, median limb fat of 7.4 kg, median visceral adipose tissue (VAT) of 84.1 cm(2), and VAT: total adipose tissue (TAT) ratio of 0.31. At week 96, estimated prevalence of lipoatrophy (upper 95% confidence interval [CI]) was 18% (25%) for ABC-3TC and 15% (22%) for TDF-FTC (P = .70); this was not significantly less than the hypothesized 15% for both (P ≥ .55 for both). The secondary as-treated (AT) analysis showed similar results. At week 96, the estimated mean percentage change from baseline in VAT was higher for the ATV-r group than for the EFV group (26.6% vs 12.4%; P = .090 in ITT analysis and 30.0% vs 14.5%; P = .10 in AT analysis); however, the percentage change in VAT:TAT was similar by ITT and AT analysis (P ≥ .60 for both). Results were similar for absolute changes in VAT and VAT:TAT. CONCLUSIONS: ABC-3TC- and TDF-FTC-based regimens increased limb and visceral fat at week 96, with a similar prevalence of lipoatrophy. Compared to the EFV group, subjects assigned to ATV-r had a trend towards higher mean percentage increase in VAT. CLINICAL TRIALS REGISTRATION: NCT00118898.

A pilot study of abacavir/lamivudine and raltegravir in antiretroviral-naïve HIV-1-infected patients: 48-week results of the SHIELD trial.

PURPOSE: to evaluate raltegravir plus abacavir/lamivudine in antiretroviral-naïve, HIV-1-infected patients. METHODS: SHIELD is an ongoing 96-week pilot study of abacavir/lamivudine 600 mg/300 mg once daily with raltegravir 400 mg twice daily among HLA-B*5701-negative adults with screening viral load (VL) > 1,000 copies/mL. HBsAg+ patients were excluded, as were patients with key mutation(s) to any study drug. Virologic failure (VF) was defined as either VL > 400 copies/mL at week 24 or confirmed virologic rebound. RESULTS: thirty-five patients enrolled (mean age 38.7 years). Most were white males, but 26% self-identified as Hispanic/Latino. At baseline, 34% had VL ≥ 100,000 copies/mL (median, 4.8 log10 copies/mL) and 20% had CD4 cell counts <200 cells/mm3 (median, 301). One patient discontinued due to adverse events (AEs); one patient experienced VF. At week 48, 91% (32/35) had VL <50 and <400 copies/mL by missing/discontinuation equals failure analysis. Median CD4 cell count change from baseline was +247 cells/mm3. Five patients (14%) had treatment-related grade 2-4 AEs; no treatment-related serious AEs were reported. Over 48 weeks, median fasting lipids increased for total (+17%), LDL (+9%), and HDL (+6%) cholesterol but remained stable for triglycerides (-1%) and total:HDL cholesterol ratio (0%). CONCLUSIONS: in this pilot study, abacavir/lamivudine plus raltegravir was effective and generally well-tolerated over 48 weeks with modest changes in fasting lipids.

Virologic response and safety of the abacavir/lamivudine fixed-dose formulation as part of highly active antiretroviral therapy: analyses of six clinical studies.

OBJECTIVE: We analyzed virologic response and safety data from six recent clinical studies conducted in antiretroviral-naïve subjects treated with ABC/3TC or its components to assess the impact of baseline viral load on efficacy and safety endpoints used in the ACTG5202 protocol. METHODS: Primary endpoints were time to virologic failure (confirmed HIV-1 RNA > or = 1,000 copies/mL at 16-24 weeks or > or = 200 copies/mL at > or = 24 weeks) and time to first grade 3 or 4 adverse event or laboratory abnormality that was at least one grade higher than at baseline. The survival distributions of both endpoints were estimated using the Kaplan-Meier method overall and by baseline viral load (<100,000 vs. 100,000 copies/mL). A weighted mean of the virologic response and 95% confidence intervals (CI) were calculated by inverse-variance weighting for baseline viral load 100,000 copies/mL across studies. RESULTS: For subjects with baseline HIV-1 RNA 100,000 copies/mL, the rate of virologic survival ranged from 87% to 95% by 48 weeks. Few subjects treated with ABC/3TC developed grade 3 or 4 adverse events, laboratory toxicities, or changes in lipid levels. The weighted mean (CI) for the pooled virologic response was 91% (87%-96%). CONCLUSION: Based on the A5202 endpoints, ABC/3TC-containing regimens in this analysis had a high rate of virologic survival and were generally well tolerated in antiretroviral-naïve subjects regardless of baseline viral load. The pooled virologic response for ABC/3TC in our analysis is higher than the A5202 estimate.

Once-daily abacavir/lamivudine and ritonavir-boosted atazanavir for the treatment of HIV-1 infection in antiretroviral-naïve patients: a 48-week pilot study.

PURPOSE: To assess the efficacy and safety of a once-daily (QD) regimen consisting of the co-formulation of abacavir/lamivudine (ABC/3TC) and atazanavir plus ritonavir (ATV-RTV) in antiretroviral (ART)-naïve patients with plasma HIV-1 RNA >5,000 copies/mL. METHOD: This open-label, multicenter study conducted between September 2004 and June 2006 included 112 patients who received ABC 600 mg/3TC 300 mg and ATV 300 mg-RTV 100 mg QD. Drug switches were permitted for ABC hypersensitivity and ATV-related hyperbilirubinemia. Primary endpoints were proportion of patients achieving HIV-1 RNA <50 copies/mL at Week 48 and treatment discontinuation due to study drugs. RESULTS: A total of 111 patients were treated. At Week 48, the proportion of patients achieving HIV-1 RNA <50 copies/mL was 77% (85/111) by intent-to-treat (ITT) missing=failure, switch included response rate. Drug substitutions occurred in 8 (7%) patients for suspected ABC hypersensitivity reaction (HSR) and in 6 (5%) patients for ATV-related toxicities; only 1 patient discontinued study due to ABC HSR. Four patients met confirmed virologic nonresponse (HIV RNA >or= 400 copies/mL). Treatment-emergent drug resistance was rare, and no patient had virus that developed reduced susceptibility to ATV. Median change from baseline (95% confidence interval) in fasting lipids at Week 48 was 39 (26-66) mg/dL for triglycerides, 28 (22-38) mg/dL for total cholesterol (C), 14 (10.5-16) mg/dL for HDL-C, and 8 (2-16.5) mg/dL for LDL-C. CONCLUSION: ABC/3TC and ATV-RTV QD is an effective and well-tolerated regimen in ART-naïve patients through 48 weeks, with a modest impact on fasting lipids.

Once-daily abacavir/lamivudine/zidovudine plus tenofovir for the treatment of HIV-1 infection in antiretroviral-naïve subjects: a 48-week pilot study.

PURPOSE: To assess the safety and efficacy of a 4-drug, 3-tablet, once-daily (qd) regimen consisting of abacavir/lamivudine/zidovudine (ABC/3TC/ZDV; 2 tablets) and tenofovir (TDF) in antiretroviral-naïve patients with plasma HIV-1 RNA 30,000 copies/mL at 48 weeks. METHOD: All participants received ABC/3TC/ZDV (300/150/300 mg) and TDF (300 mg) qd in this pilot, open-label, multicenter study. Intent-to-treat (ITT) analyses were conducted to evaluate virologic and immunologic efficacy. RESULTS: Of the 123 participants enrolled, 52 (42%) prematurely discontinued study for adverse events (14), were lost to follow-up (13), had virologic nonresponse (12), and withdrew for other reasons (13). At week 48, by ITT missing=failure analysis, 41% (51/123) and 51% (63/123) of participants had plasma HIV-1 RNA <50 copies/mL and <400 copies/mL, respectively; by ITT-observed analysis, 75% (51/68) and 93% (63/68) had plasma HIV-1 RNA <50 copies/mL and <400 copies/mL, respectively; 11% (14/123) met virologic nonresponse criteria. Median week 48 change in CD4+ cell count from baseline was +127 cells/mm3. Median week 48 changes from baseline for fasting lipids were as follows: cholesterol (-9 mg/dL), HDL (+1 mg/dL), LDL (-9 mg/dL), and triglycerides (-4 mg/dL). CONCLUSION: A high rate of premature discontinuations contributed to the overall suboptimal virologic response to ABC/3TC/ZDV+TDF qd; however, the regimen was not associated with high rates of virologic failure previously observed with TDF+ABC/3TC.

Long-term body composition changes in antiretroviral-treated HIV-infected individuals.

OBJECTIVE: Body composition impacts physical function and mortality. We compared long-term body composition changes after antiretroviral therapy (ART) initiation in HIV-infected individuals to that in HIV-uninfected controls. DESIGN: Prospective observational study. METHODS: We performed dual-energy x-ray absorptiometry (DXA) approximately 7.5 years after initial DXA in available HIV-infected individuals who received DXAs during the randomized treatment trial AIDS Clinical Trials Group A5202. For controls, we used DXA results from HIV-uninfected participants in the Boston Area Community Health/Bone and Women's Interagency HIV Study cohorts. Repeated measures analyses compared adjusted body composition changes between HIV-infected and HIV-uninfected individuals. Multivariable analyses evaluated factors associated with body composition change in HIV-infected individuals. RESULTS: We obtained DXA results in 97 HIV-infected and 614 HIV-uninfected participants. Compared with controls, HIV-infected individuals had greater adjusted lean mass and total, trunk, and limb fat gain during the first 96 weeks of ART. Subsequently, HIV-infected individuals lost lean mass compared with controls. Total, trunk, and limb fat gains after 96 weeks of ART slowed in HIV-infected individuals but remained greater than in controls. Lower CD4 T-cell count was associated with lean mass and fat gain during the initial 96 weeks of ART, but subsequently no HIV-related characteristic was associated with body composition change. CONCLUSION: Consistent with a 'return to health effect', HIV-infected individuals, especially those with lower baseline CD4 T-cell counts, gained more lean mass and fat during the first 96 weeks of ART than HIV-uninfected individuals. Continued fat gain and lean mass loss after 96 weeks may predispose HIV-infected individuals to obesity-related diseases and physical function impairment.

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.

Changes in proteinuria and albuminuria with initiation of antiretroviral therapy: data from a randomized trial comparing tenofovir disoproxil fumarate/emtricitabine versus abacavir/lamivudine.

BACKGROUND: Antiretroviral therapy (ART) is associated with improved kidney function; however, the nucleotide reverse transcriptase inhibitor (NRTI) tenofovir disoproxil fumarate (TDF) has been associated with decreased kidney function and proteinuria. METHODS: We examined changes in urine protein:creatinine (UPCR) and urine albumin:creatinine (UACR) ratios in 245 ART-naive participants in A5202 randomized in a substudy to blinded NRTI (abacavir/lamivudine, ABC/3TC, n = 124 or TDF/emtricitabine, TDF/FTC, n = 121) with open-label protease inhibitor (PI) atazanavir/ritonavir or nonnucleoside reverse transcriptase inhibitor (NNRTI) efavirenz. RESULTS: At baseline, 18% of participants had clinically significant proteinuria (UPCR ≥200 mg/g), and 11% had clinically significant albuminuria (UACR ≥30 mg/g). The prevalence of clinically significant proteinuria and albuminuria decreased from baseline to week 96 in all treatment groups. In intention-to-treat analyses, there was a significant effect of NRTI component on fold change in UPCR (P = 0.011) and UACR (P = 0.018) from baseline to week 96, with greater improvements in participants randomized to ABC/3TC. There was no significant effect of NNRTI/PI component on fold change in UPCR (P = 0.23) or UACR (P = 0.88), and no significant interactions between NRTI and NNRTI/PI components. CONCLUSIONS: In this prespecified secondary analysis, ART initiation was associated with improvements in proteinuria and albuminuria, with significantly greater improvements in participants randomized to ABC/3TC versus TDF/FTC. These are the first data from a randomized trial to suggest that initiation of TDF/FTC may not be associated with the same degree of improvement in proteinuria and albuminuria that have been reported with other regimens. Future studies should consider the long-term clinical significance of these findings.

Cystatin C-based renal function changes after antiretroviral initiation: a substudy of a randomized trial.

BACKGROUND: The effects of antiretrovirals on cystatin C-based renal function estimates are unknown. METHODS: We analyzed changes in renal function using creatinine and cystatin C-based estimating equations in 269 patients in A5224s, a substudy of study A5202, in which treatment-naive patients were randomized to abacavir/lamivudine or tenofovir/emtricitabine with open-label atazanavir/ritonavir or efavirenz. RESULTS: Changes in renal function significantly improved (or declined less) with abacavir/lamivudine treatment compared with tenofovir/emtricitabine using the Cockcroft-Gault formula (P = .016) and 2009 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI; P = .030) and 2012 CKD-EPI cystatin C-creatinine (P = .025). Renal function changes significantly improved (or declined less) with efavirenz compared with atazanavir/ritonavir (P < .001 for all equations). Mean (95% confidence interval) renal function changes specifically for tenofovir/emtricitabine combined with atazanavir/ritonavir were -8.3 (-14.0, -2.6) mL/min with Cockcroft-Gault; -14.9 (-19.7, -10.1) mL/min per 1.73(2) with Modification of Diet in Renal Disease; -12.8 (-16.5, -9.0) mL/min per 1.73(2) with 2009 CKD-EPI; +8.9 (4.2, 13.7) mL/min per 1.73(2) with 2012 CKD-EPI cystatin C; and -1.2 (-5.1, 2.6) mL/min per 1.73(2) with 2012 CKD-EPI cystatin C-creatinine. Renal function changes for the other treatment arms were more favorable but similarly varied by estimating equation. CONCLUSIONS: Antiretroviral-associated changes in renal function vary in magnitude and direction based on the estimating equation used.

Impact of randomized antiretroviral therapy initiation on glucose metabolism.

OBJECTIVE: Prior studies have found that early HIV protease inhibitors contribute to glucose dysregulation. Few randomized trials have evaluated glucose indices in antiretroviral-naive individuals on newer antiretroviral therapy (ART). METHODS: A5224s was a substudy of A5202, a prospective trial of 1857 ART-naive participants randomized to blinded abacavir-lamivudine (ABC/3TC) or tenofovir DF-emtricitabine (TDF/FTC) with open-label efavirenz (EFV) or atazanavir-ritonavir (ATV/r). Analyses used two-sample t-tests, Spearman correlation coefficients and linear regression. RESULTS: A5224s included 269 nondiabetic individuals: 85% men, 47% white non-Hispanic, baseline median age 38 years, HIV-1 RNA 4.6 log10 copies/ml and CD4 cell count 233 cells/µl. Overall, significant 96-week increases occurred in fasting glucose, insulin and the homeostatic model assessment of insulin resistance (HOMA-IR), P ≤ 0.004. Assignment to EFV (versus ATV/r) resulted in significantly greater glucose increase [mean difference 4.4; 95% confidence interval (CI) 1.3, 7.5 mg/dl; P = 0.006] but not insulin or HOMA-IR (P ≥ 0.72). Glucose indices were not significantly different between ABC/3TC and TDF/FTC arms, P ≥ 0.18. Significant correlations were detected between changes in glucose indices and changes in BMI; all r ≥ 0.23, P ≤ 0.001. In multivariable analyses, in addition to the EFV effect, higher baseline HIV-1 RNA and greater BMI change were significant independent factors associated with greater glucose increase. CONCLUSION: Changes in glucose metabolism were not significantly different between TDF/FTC and ABC/3TC-based regimens. A small but significantly greater increase in glucose was observed in those assigned to EFV. As glucose dysregulation may increase with time on ART, longer term studies will be needed to further clarify the clinical significance of these findings.

Comparison of cardiovascular disease risk markers in HIV-infected patients receiving abacavir and tenofovir: the nucleoside inflammation, coagulation and endothelial function (NICE) study.

BACKGROUND: The association between abacavir (ABC) and cardiovascular disease (CVD) risk in HIV-infected individuals is unclear. Putative mechanisms for an effect of ABC on CVD risk including endothelial dysfunction have been proposed; however, a biological mechanism has not been established. METHODS: This was a cross-sectional study of HIV-infected subjects with HIV RNA levels <400 copies/ml, who were randomly assigned to ABC or tenofovir (TDF) as initial therapy during a prior clinical trial. A small cohort of subjects on zidovudine (AZT; not randomly assigned) were studied to explore long-term exposure to this agent. All underwent brachial artery ultrasound for flow-mediated dilation (FMD), and D-dimer, high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6) and fasting lipids were measured. Between-arm differences were evaluated by multivariable linear or logistic regression modelling. RESULTS: There were 148 subjects (46 on ABC, 72 on TDF and 30 on AZT). Demographic characteristics were balanced across the groups except, as expected, AZT-treated participants were older, had higher CD4(+) T-cell counts, and longer antiretroviral therapy duration. After adjusting for age, brachial artery diameter, and treatment duration, FMD was similar in those on ABC (3.9%) and TDF (5.4%; P=0.181). FMD was higher in those on AZT (6.1%; P<0.005). Levels of IL-6, hsCRP and detectable D-dimer were similar between groups. CONCLUSIONS: Among individuals assigned to ABC or TDF in randomized clinical trials there were no significant differences in FMD or markers of inflammation and coagulation. Whether ABC contributes to risk of CVD remains unclear, but our results suggest that endothelial dysfunction, heightened inflammation, and altered coagulation are unlikely to be mechanisms by which the drug could increase CVD risk above that seen with TDF.