Switching to a protease inhibitor-containing, nucleoside-sparing regimen (lopinavir/ritonavir plus efavirenz) increases limb fat but raises serum lipid levels: results of a prospective randomized trial (AIDS clinical trial group 5125s)

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

Treatment of SARS-CoV-2 (COVID-19): A safety perspective

The goal of this review is to report a balanced perspective of current evidence for efficacy of treatments for coronavirus disease 2019 (COVID-19) against the historical safety of these treatments as of May 2021. We preselected therapies of interest for COVID-19 based on national guidelines and modified over time. We searched PubMed and Medline for these specific COVID-19 treatments and data related to their efficacy. We also searched for prior randomized controlled trials of each therapy to assess adverse effects, and we obtained the Food and Drug Administration Approval label for this information. Several drugs have been approved for the treatment of COVID-19, and many more are under study. This includes dexamethasone, remdesivir, hydroxychloroquine/chloroquine, lopinvir/ritonavir, interferon or interleukin inhibitors, convalescent plasma and several vitamins and minerals. The strongest evidence for benefit is mortality benefit with dexamethasone in patients with COVID-19 and hypoxemia, although there is a signal of harm if this is started too early. There are several other promising therapies, like interleukin inhibitors and ivermectin. Hydroxychloroquine/chloroquine, lopinvir/ritonavir, and convalescent plasma do not have enough evidence of benefit to outweigh the known risks of these drugs.

Rilpivirine plus cobicistat-boosted darunavir as a two-drug switch regimen in HIV-infected, virologically suppressed subjects on steady standard three-drug therapy: a randomized, controlled, non-inferiority trial (PROBE 2)

BACKGROUND

We explored the combination of rilpivirine plus cobicistat-boosted darunavir [a two-drug regimen (2DR)] when switching from standard triple combined ART.

METHODS

In this randomized, open-label, non-inferiority trial, participants had an HIV-RNA <50 copies/mL on a stable (>6 months) three-drug regimen. The primary endpoint was proportion with HIV-RNA <50 copies/mL at Week 24 (snapshot algorithm), with a -12% non-inferiority margin. ClinicalTrials.gov: NCT04064632.

RESULTS

One hundred and sixty patients were allocated (1:1) to 2DR or to continue current ART (CAR). At Week 24, 72 (90.0%) of participants with 2DR and 75 (93.8%) with CAR maintained HIV-RNA <50 copies/mL [difference -3.75% (95% CI = -11.63 to 5.63)], confirming non-inferiority. Non-inferiority was confirmed considering an HIV-RNA >50 copies/mL (0% for 2DR; 3.7% for CAR; 95% CI = -0.4 to 7.9). Four patients reported adverse events not leading to treatment discontinuation (one patient in the 2DR group and three patients in the CAR group); eight subjects discontinued therapy in the 2DR group and three in the CAR group. With 2DR, lipid serum concentrations increased, but differences were statistically significant only for tenofovir disoproxil fumarate-containing CAR and in 2DR patients receiving a pre-switch regimen including tenofovir disoproxil fumarate. Median bone stiffness decreased in the CAR group from 86.1 g/cm2 (IQR = 74-98) to 83.2 g/cm2 (IQR = 74-97) and increased in the 2DR group from 84.9 g/cm2 (IQR = 74-103) to 85.5 g/cm2 (IQR = 74-101). The reduction within the CAR group was significant (P = 0.043).

CONCLUSIONS

Once-daily rilpivirine plus cobicistat-boosted darunavir is an effective 2DR that combines a high virological efficacy with a potential to avoid major NRTI toxicities.

Antiretroviral Therapy-Associated Metabolic Complications: Review of the Recent Studies

The extensive utilization of antiretroviral therapy (ART) has successfully improved human immunodeficiency virus (HIV)-associated complications. The incidence of opportunistic infections is decreased by the viral load suppression and the CD4 count promotion. However, metabolic complications, commonly bone demineralization, lipodystrophy, and lactic acidosis, are arising following the adaptation of long-term ART. The events are not drug-specific, but the severity and incidence individually vary depending upon classes of drugs. Such concerning occurrences may lead to discontinuation of current therapy or switching to another regimen with fewer adverse effects. The purpose of this review is to demonstrate the common metabolic abnormalities associated with each class of widely used ART in people living with HIV (PLHIV). Electronic databases such as PubMed, ScienceDirect, Scopus, Google Scholar, SciFinder, and Web of Science were used for the literature search. A better understanding of ART-associated metabolic adverse effects is helpful in various clinical settings so that therapists may optimize treatments in this population.

NRTI Sparing Therapy in Virologically Controlled HIV-1 Infected Subjects: Results of a Controlled, Randomized Trial (Probe)

Dual treatments could help clinicians to avoid drawbacks and toxicities due to the nucleosidic backbone, while maintaining the efficacy and convenience of robust combination antiretroviral therapy (cART). We explored the combination of rilpivirine plus boosted darunavir (DRV) as an option when switching from standard cART in patients who are virologically suppressed. In this randomized, open-label, proof-of-concept, noninferiority trial, we recruited patients aged 18 years or older with chronic HIV-1 infection and on a stable, effective (>6 months) protease inhibitor-based cART including a nucleosidic backbone. The primary endpoint was noninferiority of the virological response between treatment groups, according to FDA snapshot approach. Sixty patients were randomly allocated to dual treatment with rilpivirine plus boosted DRV or to continue their ongoing triple treatment. Noninferiority was shown at the prespecified level of -12% both at 24 and 48 weeks. At week 24, 100% of patients in the dual arm presented a blood HIV-RNA level <50 copies per milliliter compared with 90.1% in the triple drug arm (difference 9.9%, 95% CI: -0.7 to 20.7), whereas, at 48 weeks, the same proportions were 96.7% and 93.4%, respectively (difference 3.3%, 95% CI: -7.15 to 13.5). The mean change in CD4 cell count from baseline was 6.0 cells per microliter (SD, 184) for dual treatment and 16.5 cells per microliter (SD, 142) for triple treatment. A relevant decrement in CD838HLADR cells was observed in both arms. The reduction was, however, significantly more pronounced in the dual-therapy arm. At week 48, the CD838HLADR cell count was 3.4% (SD, 2.2) in the dual-therapy arm and 5.2% (SD, 3.1) in the triple arm (P = 0.018). None of the patients developed severe adverse events nor had to stop treatment because of adverse events or presented grade 3-4 laboratory abnormalities. A greater reduction of bone stiffness (-2.25; SD, 7.1) was observed in patients randomized to continue triple therapy compared with patients switched to dual therapy (-0.32; SD, 8.8). Finally, baseline HIV-DNA content directly correlated with pre-cART viral load of patients (P = 0.021), but not with time on cART or time with HIV-RNA below 50 copies per milliliter. Independently of the study arm, patients with a n HIV-RNA level constantly above 3 copies per milliliter or showing viral blips had baseline HIV-DNA levels significantly higher (64,656 copies per 10 cells; SD, 93057) compared with patients who constantly presented a HIV-RNA level below the detection limit of 3 copies per milliliter (14,457 copies per 10 cells; SD, 14098) (P = 0.001). A rilpivirine-boosted plus ritonavir-boosted DRV therapy was not inferior over 48 weeks to a standard boosted protease inhibitor-based triple cART. The dual therapy did not negatively affect lipid profile and renal function and was more friendly on bone metabolism. This approach constitutes an alternative for patients experiencing nucleoside reverse transcriptase inhibitor-related toxicities.

Dual Therapy Treatment Strategies for the Management of Patients Infected with HIV: A Systematic Review of Current Evidence in ARV-Naive or ARV-Experienced, Virologically Suppressed Patients

OBJECTIVE

We reviewed the current literature regarding antiretroviral (ARV)-sparing therapy strategies to determine whether these novel regimens can be considered appropriate alternatives to standard regimens for the initial treatment of ARV-naive patients or as switch therapy for those patients with virologically suppressed HIV infection.

METHODS

A search for studies related to HIV dual therapy published from January 2000 through April 2014 was performed using Biosis, Derwent Drug File, Embase, International Pharmaceutical Abstracts, Medline, Pascal, SciSearch, and TOXNET databases; seven major trial registries, and the abstracts of major conferences. Using predetermined criteria for inclusion, an expert review committee critically reviewed and qualitatively evaluated all identified trials for efficacy and safety results and potential limitations.

RESULTS

Sixteen studies of dual therapy regimens were critiqued for the ARV-naive population. Studies of a protease inhibitor/ritonavir in combination with the integrase inhibitor raltegravir or the nucleoside reverse transcriptase inhibitor lamivudine provided the most definitive evidence supporting a role for dual therapy. In particular, lopinavir/ritonavir or darunavir/ritonavir combined with raltegravir and lopinavir/ritonavir combined with lamivudine demonstrated noninferiority to standard of care triple therapy after 48 weeks of treatment. Thirteen trials were critiqued in ARV-experienced, virologically suppressed patients. The virologic efficacy outcomes were mixed. Although overall data regarding toxicity are limited, when compared with standard triple therapy, certain dual therapy regimens may offer advantages in renal function, bone mineral density, and limb fat changes; however, some dual combinations may elevate lipid or bilirubin levels.

CONCLUSIONS

The potential benefits of dual therapy regimens include reduced toxicity, improved tolerability and adherence, and reduced cost. Although the data reviewed here provide valuable insights into the effectiveness and tolerability of dual therapy regimens, it remains unclear whether these potential benefits can be maintained long-term. Appropriately powered studies with longer follow-up periods are needed to more definitively assess potential toxicity reduction advantages with dual therapy.

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.

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.

Dual therapy with lopinavir and ritonavir plus lamivudine versus triple therapy with lopinavir and ritonavir plus two nucleoside reverse transcriptase inhibitors in antiretroviral-therapy-naive adults with HIV-1 infection: 48 week results of the randomised, open label, non-inferiority GARDEL trial

BACKGROUND

Daily oral triple therapy is effective at halting HIV disease progression, but can have toxic effects and is costly. We investigated whether dual therapy with lopinavir and ritonavir plus lamivudine is non-inferior to standard triple therapy.

METHODS

The GARDEL study (Global AntiRetroviral Design Encompassing Lopinavir/r and Lamivudine vs LPV/r based standard therapy) is a 48 week, phase 3, randomised, controlled, open-label, non-inferiority trial in antiretroviral-therapy-naive adults (age ≥18 years) with documented HIV-1 RNA viral load of at least 1000 copies per mL. The study was done at 19 centres in six countries. Patients were randomly assigned (1:1) to dual therapy or triple therapy by sealed envelopes, in blocks of four, stratified by baseline viral load (<100,000 vs ≥100,000 copies per mL). Dual therapy consisted of lopinavir 400 mg and ritonavir 100 mg plus lamivudine 150 mg, both twice daily. Triple therapy consisted of lopinavir 400 mg and ritonavir 100 mg twice daily and lamivudine or emtricitabine plus another nucleoside reverse transcriptase inhibitor (NRTI) in fixed-dose combination. Efficacy was analysed in all participants who received at least one dose of study drug. The primary endpoint was virological response rate, defined as the proportion of patients with HIV RNA less than 50 copies per mL at 48 weeks. Dual therapy was classed as non-inferior to triple therapy if the lower bound of the 95% CI for the difference between groups was no lower than -12%. Patients and investigators were unmasked to treatment allocation. This study is registered with ClinicalTrials.gov, number NCT01237444.

FINDINGS

Between Dec 10, 2010, and May 15, 2012, 217 patients were randomly assigned to the dual-therapy group and 209 to the triple-therapy group. 198 patients in the dual-therapy group and 175 in the triple-therapy group completed 48 weeks of treatment. At week 48, 189 patients (88·3%) in the dual-therapy group and 169 (83·7%) in the triple-therapy group had viral response (difference 4·6%, 95% CI -2·2 to 11·8; p=0·171). Patients with baseline viral load of at least 100,000 copies per mL showed similar results (87·2% vs 77·9%, respectively; difference 9·3%, 95% CI -2·8 to 21·5; p=0·145). Toxicity-related or tolerability-related discontinuations were more common in the triple-therapy group (n=10 [4·9%]) than in the dual-therapy group (n=1 [0·4%]; difference 4·5%, 95% CI -8·1 to -0·9; p=0·011). 65 adverse events in the dual-therapy group and 88 in the triple-therapy group were possibly or probably drug related (p=0·007). Two serious adverse events occurred, both in the dual-therapy arm, one of which (a case of gastritis) was reported as possibly or probably related to drug treatment.

INTERPRETATION

Dual therapy with lopinavir and ritonavir plus lamivudine regimen warrants further clinical research and consideration as a potential therapeutic option for antiretroviral-therapy-naive patients.

FUNDING

Fundación Huésped and AbbVie.

Systematic review of antiretroviral-associated lipodystrophy: lipoatrophy, but not central fat gain, is an antiretroviral adverse drug reaction

Background

Lipoatrophy and/or central fat gain are observed frequently in patients on antiretroviral therapy (ART). Both are assumed to be antiretroviral adverse drug reactions.

Methods

We conducted a systematic review to determine whether fat loss or gain was more common in HIV-infected patients on ART than in uninfected controls; was associated with specific antiretrovirals; and would reverse after switching antiretrovirals.

Results

Twenty-seven studies met our inclusion criteria. One cohort study reported more lipoatrophy, less subcutaneous fat gain, but no difference in central fat gain in HIV-infected patients on ART than in controls. Randomised controlled trials (RCTs) showed more limb fat loss (or less fat gain) with the following regimens: stavudine (versus other nucleoside reverse transcriptase inhibitors (NRTIs)); efavirenz (versus protease inhibitors (PIs)); and NRTI-containing (versus NRTI-sparing). RCTs showed increased subcutaneous fat after switching to NRTI-sparing regimens or from stavudine/zidovudine to abacavir/tenofovir. There were no significant between-group differences in trunk and/or visceral fat gain in RCTs of various regimens, but results from efavirenz versus PI regimens were inconsistent. There was no significant between-group differences in central fat gain in RCTs switched to NRTI-sparing regimens, or from PI-containing regimens.

Conclusions

There is clear evidence of a causal relationship between NRTIs (especially thymidine analogues) and lipoatrophy, with concomitant PIs possibly having an ameliorating effect or efavirenz causing additive toxicity. By contrast, central fat gain appears to be a consequence of treating HIV infection, because it is not different from controls, is not linked to any antiretroviral class, and doesn't improve on switching.

Switching to lopinavir/ritonavir with or without abacavir/lamivudine in lipoatrophic patients treated with zidovudine/abacavir/lamivudine

BACKGROUND

Discontinuation of thymidine nucleoside reverse transcriptase inhibitors (tNRTIs) is the only proven strategy for improving lipoatrophy. It is unclear whether switching to NRTI-sparing or to non-thymidine NRTI-containing therapy has differential effects on body fat recovery.

METHODS

This was a 96 week, open-label, randomized study in suppressed patients with moderate/severe lipoatrophy and no prior virological failure while receiving a protease inhibitor and who had their triple NRTI regimen (zidovudine/lamivudine/abacavir) switched to lopinavir/ritonavir plus abacavir/lamivudine for a 1 month run-in period and then randomized to lopinavir/ritonavir plus abacavir/lamivudine versus lopinavir/ritonavir monotherapy. The KRETA trial is registered with ClinicalTrials.gov (number NCT00865007).

RESULTS

Of 95 patients included, 88 were randomized to lopinavir/ritonavir plus abacavir/lamivudine (n = 44) or lopinavir/ritonavir monotherapy (n = 44). Median (IQR) baseline limb fat was 2.5 (1.6-3.7) kg in the lopinavir/ritonavir plus abacavir/lamivudine group and 2.5 (2.0-5.4) kg in the lopinavir/ritonavir monotherapy group. Six patients in the triple therapy group and 13 in the monotherapy group had discontinued study drugs by week 96. Although there were limb fat gains in each group at weeks 48/96 (+324/+358 g in lopinavir/ritonavir plus abacavir/lamivudine, P = 0.09/0.07, versus +215/+416 g in the lopinavir/ritonavir monotherapy group, P = 0.28/0.16), differences between groups were not significant [difference +109 g (95% CI -442, +660)/-57 g (95% CI -740, +625)].

CONCLUSIONS

In lipoatrophic patients treated with zidovudine/lamivudine/abacavir, switching to lopinavir/ritonavir monotherapy had no additional benefit in limb fat recovery relative to switching to lopinavir/ritonavir with abacavir/lamivudine. These data suggest that non-thymidine nucleosides such as abacavir/lamivudine are not an obstacle to limb fat recovery.

Disorders of fat partitioning in treated HIV-infection

HIV-associated lipodystrophy is clinically characterized by body fat changes including subcutaneous fat loss (lipoatrophy) with or without truncal fat accumulation (lipohypertrophy). Thymidine nucleoside reverse transcriptase inhibitors, stavudine and to a lesser extent zidovudine, are major contributors for lipoatrophy. Drug factors are not clear for lipohypertrophy. Restoration to health with effective viral suppression and weight gain may be factors playing significant roles in lipohypertrophy. Mitochondrial dysfunction and inflammation in subcutaneous adipose tissue are key factors in the pathogenesis of HIV-associated lipoatrophy. The pathogenesis of lipohypertrophy is less well understood. Switching from thymidine nucleoside reverse transcriptase inhibitors restores subcutaneous fat in patients with HIV-associated lipoatrophy, but improvement is slow and limited. Surgical filling cosmetically improves facial lipoatrophy. Exercise and diet may reduce increased visceral adipose tissue. Liposuction may be useful to remove superficial, localized fat accumuli.

From old to new nucleoside reverse transcriptase inhibitors: changes in body fat composition, metabolic parameters and mitochondrial toxicity after the switch from thymidine analogs to tenofovir or abacavir

INTRODUCTION

Thymidine analogs zidovudine (AZT) and stavudine (d4T) have been widely used because of their antiviral activity against HIV, but at the expense of high toxicity, mainly related to mitochondrial damage. Many studies have been performed replacing AZT or d4T with newer nucleoside analogs reverse transcriptase inhibitors (NRTIs) with less toxicity, such as tenofovir (TDF) or abacavir (ABC), maintaining virological efficacy.

AREAS COVERED

Relevant literature was identified using a PubMed search of articles published up to June 2010. Search terms included: 'thymidine analogs', 'stavudine', 'zidovudine', 'd4T', 'AZT', 'ZDV', 'treatment switch'. Original articles in which d4T or AZT had been replaced by TDF or ABC as switch strategies (with undetectable viral load) were reviewed where information about body fat distribution, mitochondrial functionality and/or plasma lipid parameters were available. Relevant references from these articles were also considered. Only studies performed in adult patients (18 years or older) are included. The readers will gain a better understanding of the toxicity caused by thymidine analogs, the treatment alternatives and the benefits observed after treatment switch to newer NRTIs.

EXPERT OPINION

Thymidine analogs AZT and d4T yield considerable toxicity and proactive switch to newer NRTIs such as TDF or ABC is necessary in order to avoid or partially reverse such side effects.

Effect of antioxidants on mitochondrial function in HIV-1-related lipoatrophy: a pilot study

We investigated the effect of antioxidant supplementation on mitochondrial function, fat distribution, and lipid and glucose metabolism in HIV-1-infected patients with antiretroviral therapy (ART)-related lipoatrophy. 61 ART-treated HIV-1-infected patients with lipoatrophy were randomized to receive either n-acetyl-L-carnitine (n = 21), lipoic acid + n-acetylcisteine (LA/NAC) (n = 20), or no supplementation (n = 20) for 48 weeks. At baseline and at the end of treatment, mitochondrial function was studied by (13)C-methionine breath test and by mitochondrial (mt)-DNA quantification on circulating T-cells and subcutaneous adipose tissue. Body composition was assessed by dual-energy X-ray absorpiometry (DEXA). (13)CO(2)-exhalation increased between baseline and week 48 in both supplementation arms as evidenced by a higher delta over baseline excretion at 45 min (from mean ± SEM of 7.8 ± 1.08 to 9.9 ± 0.6, p = 0.04 in the n-acetyl-carnitine arm, and from 7.4 ± 0.8 to 11.5 ± 1.6, p = 0.01 in LA/NAC arm). Cumulative (13)CO2 excretion increased from median (interquartile range; IQR) of 3.25 (2.55-4.2) to 4.51 (4.12-5.2) in the carnitine arm; from 3.79 (2.67-4.37) to 4.83 (4.25-5.56) in the LA/NAC arm; p = 0.004, 0.02, respectively. mtDNA content increased in CD4+ T-cells from patients who received n-acetyl-carnitine (+30 copies/cell; p = 0.03), without significant difference by the overall comparison of the study groups. Fat body mass and lipid profile did not change significantly in any of the arms. Our study showed that antioxidant supplementation may have a protective role on mitochondrial function, with limited effects on the reversal of clinical lipodystrophic abnormalities in HIV-1-infected patients.

Lipid Metabolism and Cardiovascular Risk in HIV-1 Infection and HAART: Present and Future Problems

Many infections favor or are directly implicated with lipid metabolism perturbations and/or increased risk of coronary heart disease (CHD). HIV itself has been shown to increase lipogenesis in the liver and to alter the lipid profile, while the presence of unsafe habits, addiction, comorbidities, and AIDS-related diseases increases substantially the risk of cardiovascular disease (CVD) in the HIV-infected population. Antiretroviral therapy reduces such stimuli but many drugs have intrinsic toxicity profiles impacting on metabolism or potential direct cardiotoxicity. In a moment when the main guidelines of HIV therapy are predating the point when to start treating, we mean to highlight the contribution of HIV-1 to lipid alteration and inflammation, the impact of antiretroviral therapy, the decisions on what drugs to use to reduce the probability of having a cardiovascular event, the increasing use of statins and fibrates in HIV-1 infected subjects, and finally the switch strategies, that balance effectiveness and toxicity to move the decision to change HIV drugs. Early treatment might reduce the negative effect of HIV on overall cardiovascular risk but may also evidence the impact of drugs, and the final balance (reduction or increase in CHD and lipid abnormalities) is not known up to date.

New and emerging agents in the management of lipodystrophy in HIV-infected patients

Lipodystrophy remains a major long-term complication in human immunodeficiency virus-infected patients under antiretroviral (ARV) therapy. Patients may present with lipoatrophy or lipohypertrophy or both. The choice of treatments to improve fat redistribution depends on the form of lipodystrophy and its duration. Measures known to improve lipoatrophy are switches in ARV therapy (stavudine or zidovudine to abacavir or tenofovir) and filling interventions. Pioglitazone may be added to these measures, although any benefits appear small. Uridine and leptin were found to be disappointing so far. Regarding lipohypertrophy, diet and exercise, recombinant human growth hormone, and metformin may reduce visceral fat, but may worsen subcutaneous lipoatrophy. Surgical therapy may be required. Attractive pharmacologic treatments include growth hormone-releasing factor and leptin. Adiponectin and adiponectin receptors are promising therapeutic targets to explore.

Regional adipose tissue measured by MRI over 5 years in HIV-infected and control participants indicates persistence of HIV-associated lipoatrophy

OBJECTIVE

Peripheral fat loss and visceral fat gain have been reported in HIV infection. There are limited data on long-term change in adipose tissue in HIV-infected patients vs. controls. Therefore, we determined change in regional adipose tissue from baseline examination to 5 years later among participants in the study of Fat Redistribution and Metabolic Change in HIV Infection.

METHODS

Regional adipose tissue volume was measured using MRI at both examinations in 477 HIV-infected and 214 control men and women. Lipoatrophy was defined as leg subcutaneous adipose tissue (SAT) below the cutoff point marking the lowest decile (10%) of controls at each examination.

RESULTS

HIV-infected and control participants showed similar adipose tissue gains. In men, all SAT depots and visceral adipose tissue started lower and remained lower on average in HIV-infected vs. controls. In women, leg and arm SAT also started lower and remained lower in HIV-infected vs. controls. Mean leg SAT of HIV-infected men was 67% of control men at baseline and 65% at follow-up; for women 83% and 77%. At baseline, 48% of HIV-infected participants had lipoatrophy; on average those with baseline lipoatrophy gained 0.96L of leg SAT compared with 1.23L gain for controls in the lowest decile (P = 0.16). At follow-up, 53% of HIV-infected participants had lipoatrophy. In multivariable models, discontinuation of stavudine appeared to produce little gain in leg SAT ( approximately 1.1%/year).

CONCLUSION

HIV-infected participants did not substantially recover SAT compared with controls, although both showed average gains. HIV-associated lipoatrophy persisted after 5 years of follow-up.

Total body and spinal bone mineral density across Tanner stage in perinatally HIV-infected and uninfected children and youth in PACTG 1045

OBJECTIVE

To characterize total body bone mineral content (BMC) and total body and spinal bone mineral density (BMD) in perinatally HIV-infected and uninfected children/youth across puberty.

DESIGN

HIV-infected (7-24 years) were randomly selected from six strata based on Tanner stage/protease inhibitor use. HIV-uninfected were frequency-matched by Tanner group and sociodemographic background to the HIV-infected.

METHODS

Dual-energy X-ray absorptiometry (DXA) measured BMC and BMD. Linear regression models tested differences in bone outcomes by HIV and the interaction of HIV by Tanner group (1-2, 3-4, 5). Models were performed separately by sex and adjusted for DXA scanner, race/ethnicity, height, age and lean body mass.

RESULTS

HIV-infected (N = 236) and uninfected (N = 143) were comparable on sex and race/ethnicity. HIV-infected were slightly older (median 12.6 versus 11.9 years). In adjusted models, HIV-infected males had significantly lower total body BMC and total body and spinal BMD at Tanner 5, lower BMC at Tanner 3-4 and similar BMC and BMD at Tanner 1-2, compared to HIV-uninfected males. HIV-infected and uninfected girls did not differ significantly on any bone outcome, but there was a marginally significant interaction of HIV and Tanner group for spinal BMD. Kaletra/ritonavir was associated with lower BMC and total body BMD and nevirapine was associated with higher spinal BMD in a model with all HIV-infected.

CONCLUSIONS

Perinatally HIV-infected males showed more evidence of lower bone density especially in the final stage of pubertal development than HIV-infected girls and they may be at increased risk for bone disease during adulthood.

The SWITCHMRK studies: substitution of lopinavir/ritonavir with raltegravir in HIV-positive individuals

Protease inhibitors potently suppress HIV viral load but are often associated with metabolic disturbances such as dyslipidemias and lipodystrophy. In addition to exercise, diet modification and anti-lipid therapies, one potential management strategy for HIV-positive patients with dyslipidemia is to switch any antiretrovirals that may be exacerbating the condition to more lipid-neutral drugs. The SWITCHMRK studies examined the effects of substituting lopinavir/ritonavir, a protease inhibitor known to cause dyslipidemias, with the integrase inhibitor raltegravir. Participants who switched from lopinavir/ritonavir to raltegravir experienced an improvement in cholesterol and triglycerides at 12 weeks; however, a large proportion of patients in the raltegravir arms did not maintain HIV virologic suppression at less than 50 copies/ml at week 24. Further analyses are underway to determine why more patients in the raltegravir arms experienced increased virologic failure and to determine whether switching lopinavir/ritonavir with raltegravir may be appropriate for specific subgroups of patients.

Clinical management of HIV-associated lipodystrophy

PURPOSE OF REVIEW

Lipodystrophy or fat re-distribution, and its associated metabolic abnormalities, are common in HIV patients. The pathogenesis is multifactorial. This article provides an update on the latest findings of the different clinical management strategies that have been utilized in patients with lipodystrophy.

RECENT FINDINGS

Treatment strategies need to be different in those patients with lipoatrophy when compared with patients with central fat accumulation (lipohypertrophy). Most of the treatments studied have produced minimal or modest effects, which are not sustained when the therapy is discontinued. The treatment of associated metabolic abnormalities such as insulin resistance and hyperlipidemia should have similar goals to that in the non-HIV population, but is complicated by the fact that response may be worse and there is a need to consider drug-drug interactions with the antiretrovirals.

SUMMARY

Multiple complex strategies will need to be utilized in these patients to treat the different features seen in lipodystrophy in order to reduce their long-term cardiovascular risk. Further research is also needed to evaluate combination therapies and to identify the underlying mechanisms in order to develop novel therapies for the future.

Zidovudine/lamivudine for HIV-1 infection contributes to limb fat loss

Background

Lipoatrophy is known to be associated with stavudine as part of the treatment for HIV infection, but it is less clear if this serious side effect is also related to other nucleoside reverse transcriptase inhibitors like zidovudine. We aimed to determine whether zidovudine-sparing first-line antiretroviral therapy would lead to less lipoatrophy and other metabolic changes than zidovudine-containing therapy.

Methodology/Principal Findings

Fifty antiretroviral therapy-naïve HIV-1 infected men with an indication to start antiretroviral therapy were included in a randomized single blinded clinical trial. Randomisation was between zidovudine-containing therapy (zidovudine/lamivudine+lopinavir/ritonavir) and zidovudine-sparing therapy (nevirapine+lopinavir/ritonavir). Main outcome measures were body composition assessed by computed tomography and dual-energy X-ray absorptiometry scan and lipid profile before and after 3, 12, 24 months of antiretroviral therapy. In the zidovudine/lamivudine+lopinavir/ritonavir group, from 3 months onward limb fat decreased progressively by 684±293 grams (estimated mean±standard error of the mean)(p = 0.02) up to 24 months whereas abdominal fat increased, but exclusively in the visceral compartment (+21.9±8.1 cm², p = 0.008)). In contrast, in the nevirapine+lopinavir/ritonavir group, a generalized increase in fat mass was observed. After 24 months no significant differences in high density lipoprotein and total/high density lipoprotein cholesterol ratio were found between both treatment groups, but total and low density lipoprotein cholesterol levels were higher in the nevirapine+lopinavir/ritonavir group (6.1±0.2 versus 5.3±0.2 and 3.6±0.1 versus 2.8±0.1 mmol/l respectively, p<0.05). Virologic response and safety were comparable in both groups.

Conclusions/Significance

Zidovudine/lamivudine+lopinavir/ritonavir, but not nevirapine+lopinavir/ritonavir in antiretroviral therapy-naïve patients, is associated with lipoatrophy and greater relative intraabdominal lipohypertrophy, suggesting that zidovudine/lamivudine contributes to both these features of lipodystrophy. These findings support to no longer consider zidovudine/lamivudine as one of the preferred possible components of first-line antiretroviral therapy where alternative treatments are available.

Trial Registration

ClinicalTrials.gov NCT 00122226

The human immunodeficiency virus and the cardiometabolic syndrome in the developing world: an African perspective

The advent of highly active antiretroviral therapy (HAART) has transformed human immunodeficiency virus (HIV)/AIDS into a manageable chronic disorder. Clinical care, however, needs to address the metabolic, anthropometric, and cardiovascular changes associated with HIV infection and HAART. Studies in developing countries suggest an increasing incidence of HIV-associated cardiometabolic syndrome (CMS), especially in urban settings. Predictions indicate that the greatest increase in the prevalence of diabetes will occur in Africa over the next 2 decades due to lifestyle changes. This, coupled with increased access to HAART, may exponentially increase the prevalence of CMS in developing countries, where HIV infection is prevalent. Appropriate evaluation and intervention programs need to be implemented in the developing world, especially sub-Saharan Africa, to curtail HIV-related CMS. This should include routine cardiovascular risk assessments, management of HIV infection with more "metabolically friendly" HAART, and encouragement of lifestyle modifications, particularly smoking cessation, weight management, regular exercise, and adherence to a healthy diet.

Peripheral and visceral fat changes following a treatment switch to a non-thymidine analogue or a nucleoside-sparing regimen in HIV-infected subjects with peripheral lipoatrophy: results of ACTG A5110

BACKGROUND

Switching a thymidine analogue to a non-thymidine analogue or changing to a nucleoside-sparing regimen has been shown to partially reverse peripheral lipoatrophy. The current study evaluated both approaches.

METHODS

Subjects at 15 AIDS Clinical Trial Group sites receiving thymidine analogue stavudine- or zidovudine-containing regimens with plasma HIV RNA < or =500 copies/mL and lipoatrophy were prospectively randomized to: (i) switch the thymidine analogue to abacavir; (ii) discontinue all antiretrovirals and switch to lopinavir/ritonavir plus nevirapine (LPV/r+NVP); or (iii) delay switching for 24 weeks (ClinicalTrials.gov identifier: NCT00028314). Single-slice computer tomography of mid-thigh and abdominal fat and metabolic and virological/immunological parameters were measured at baseline and weeks 24 and 48.

RESULTS

Among the 101 patients enrolled, there were significant subcutaneous thigh fat and subcutaneous abdominal tissue (SAT) increases over time and decreases in visceral adipose tissue to total adipose tissue (VAT:TAT) ratios for both interventions, and a decrease in VAT for abacavir. CD4 increased in the LPV/r+NVP arm. LPV/r+NVP had a significantly shorter time to grade 3 or higher toxicity (P = 0.007), but discontinuation rates were similar. Glucose levels did not change, but insulin decreased in the LPV/r+NVP arm. Lipids tended to increase in the LPV/r+NVP arm.

CONCLUSIONS

Switching stavudine or zidovudine to a non-thymidine analogue or changing to a nucleoside reverse transcriptase inhibitor-sparing regimen is associated with qualitatively similar improvements in thigh fat, SAT and VAT:TAT ratio at 48 weeks. Abacavir also resulted in VAT reductions and LPV/r+NVP resulted in CD4 count increases.

Cardiovascular complications in HIV management: past, present, and future

Highly active antiretroviral therapy (HAART) has significantly improved the prognosis for many individuals with HIV infection. Consequently, HIV infection has become a chronic and manageable disease. The focus on long-term management of patients with HIV infection has broadened to include comorbid conditions, most notably cardiovascular disease. Patients with HIV infection share many cardiovascular risk factors with the general population, and HIV infection itself may increase cardiovascular risk. Changes in lipid profiles associated with increased cardiovascular risk that have been observed with some HAART regimens have been a cause for concern among clinicians who treat HIV-infected patients. However, the lipid effects of HAART seem to depend on the type and duration of regimens employed. They can be managed effectively according to current guidelines that recommend lifestyle changes (eg, improved diet, increased exercise, smoking cessation) and pharmacologic therapy described in established treatment paradigms for patients on antiretroviral therapy and similar to measures currently used by the general population. A review of the clinical data indicates that the virologic and immunologic benefits of HAART clearly outweigh any metabolic effects observed in some patients over time and that preexisting, established cardiovascular risk factors contribute significantly to the potential development of cardiovascular events. These benefits of antiretroviral therapy have been demonstrated in studies comparing the superior efficacy of continuous vs. intermittent HAART.

Body-fat abnormalities in patients with HIV: progress and challenges

The introduction of newer antiretroviral drugs has provided greater levels of HIV suppression with fewer of the metabolic effects, lipoatrophy, and body habitus changes associated with earlier therapies. Previously classified under the collective term, lipodystrophy, lipoatrophy and body-fat changes are now known to occur independently in some HIV-infected patients, depending on the type and duration of antiretroviral therapy and a myriad of factors including HIV infection alone that contribute significantly to these changes. This article reviews the current scientific literature and recent clinical trial results that distinguish lipoatrophy or dyslipidemia pathophysiologically from body-fat changes seen as central and peripheral lipohypertrophy and fat redistribution, as well as the nature and extent of changes associated with HIV infection alone and newer antiretroviral therapies. This information may assist physicians in identifying individual risk factors and choosing the type of antiretroviral therapy that may minimize these changes without loss of virologic suppression.

Metabolic complications of antiretroviral therapy in HIV-infected children

The purpose of this review is to describe the metabolic complications associated with antiretroviral therapy in HIV-infected children. As a result of extensive research over the last 10 years, there is a greater awareness and understanding of these conditions. However, in resource-limited settings, where the majority of HIV-infected children live, the prevalence and risk factors of metabolic complications are largely unknown. Limited diagnostic resources contribute to this impediment. Therapies for these conditions are still under investigation, including prevention and optimal treatment of reduced bone mineral density, osteopaenia and osteoporosis. Future research goals should be directed towards closing the diagnostic and treatment gaps between rich and poor settings.

Relationships between Drug Exposure, Changes in Metabolic Parameters and Body Fat in HIV-Infected Patients Switched to a Nucleoside Sparing Regimen

Background

The pathogenesis of metabolic disturbances in treated HIV infection is incompletely understood.

Methods

Relationships between fasted metabolic parameters, body composition, and drug plasma concentrations were investigated in 59 patients who switched from failed nucleoside analogue treatment to ritonavir-boosted indinavir and efavirenz therapy. Metabolic parameters, peripheral fat, visceral adipose tissue (VAT) and drug plasma concentrations were measured prospectively.

Results

Ritonavir exposure was found to be negatively correlated with high-density lipoprotein cholesterol (HDL-c) changes, with a 2.4% decrease in HDL-c for each unit increase in ritonavir concentration ratio. Significant associations between indinavir or efavirenz concentrations and metabolic disturbances were not observed. Total cholesterol (TC) correlated positively with high body mass index (BMI) and negatively with baseline limb fat mass: each unit increase in BMI and each kilogram reduction in baseline limb fat corresponded with a TC increase of 2.4% and 4.1%, respectively. Baseline triglyceride levels were lower in those patients with relatively greater limb fat mass: each kilogram reduction of total limb fat mass was associated with a 15.7% increase in triglyceride concentration. Changes in VAT were positively correlated with TC: for every unit TC increase a 0.3% VAT increase was observed (over 48 weeks).

Conclusions

Reduced limb fat mass at the start of the study treatment, increases in VAT mass, and higher plasma concentrations of ritonavir on study treatment were each - to varying degrees - associated with various metabolic disturbances.