Ezetimibe alone reduces low-density lipoprotein cholesterol in HIV-infected patients receiving combination antiretroviral therapy

Effectiveness of ezetimibe in human immunodeficiency virus patients treated for hyperlipidaemia: a systematic review and meta-analysis

OBJECTIVE

Systematic review and meta-analysis of lipid outcomes for human immunodeficiency virus (HIV)-positive or HIV-infected patients treated with ezetimibe.

METHODS

We conducted a literature search from 1946 to 2021 for trials studying the effectiveness of ezetimibe in hyperlipidaemic HIV patients. We included trials of all designs in which HIV patients on highly active antiretroviral therapy (HAART)/non-nucleoside reverse transcriptase inhibitor (NNRTI) therapy had hyperlipidaemia, were treated with ezetimibe, and reported lipid outcomes.

RESULTS

Of thirteen eligible trials, five were randomized controlled trials (RCTs) and eight were single-arm trials. Two of the eligible RCTs were placebo-controlled; we performed a meta-analysis across those two trials for low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglyceride (TG). LDL-C was significantly lower in the ezetimibe arm (net change: -23.56 mg/dL, 95% CI: -40.22, -6.90 mg/dL). We then performed meta-analysis of the single-arm trials examining lipid outcomes after ezetimibe treatment which, like in the RCTs, revealed significant reductions of LDL-C (-23.89 mg/dL, 95% CI -29.94 to -17.83 mg/dL). In addition, significant reductions were seen for total cholesterol (TC) (-26.17 mg/dL, 95% CI -32.81 to -19.54 mg/dL) and TG (-18.57 mg/dL, 95% CI -34.01 to -3.14 mg/dL) but HDL-C did not show a change.

CONCLUSIONS

Evidence for LDL-C reduction is limited in RCTs; single-arm trial LDL-C reductions are consistent with the RCTs. In addition, significant reductions in TC and TG were also seen in the meta-analysis of the single arm trials. The single-arm trials' meta-analysis corroborates evidence from RCTs to suggest that ezetimibe can be an option for hyperlipidaemia among HIV patients with mildly elevated TC and LDL-C levels, especially in cases where statins are contra-indicated due to drug-drug interactions with concomitant anti-retroviral therapy.

Mechanisms and primary prevention of atherosclerotic cardiovascular disease among people living with HIV

PURPOSE OF REVIEW

To highlight mechanisms of elevated risk of atherosclerotic cardiovascular disease (ASCVD) among people living with HIV (PLWH), discuss therapeutic strategies, and opportunities for primary prevention.

RECENT FINDINGS

HIV-associated ASCVD risk is likely multifactorial and due to HIV-specific factors and traditional risk factors even in the setting of treated and suppressed HIV disease. Although a growing body of evidence suggests that inflammation and immune activation are key drivers of atherogenesis, therapies designed to lower inflammation including colchicine and low-dose methotrexate have not improved secondary cardiovascular endpoints among PLWH. Statins continue to be the mainstay of management of hyperlipidemia in HIV, but the impact of newer lipid therapies including proprotein convertase subtilisin/kexin type 9 inhibitors on ASCVD risk among PLWH is under investigation. Aside from the factors mentioned above, healthcare disparities are particularly prominent among PLWH and thus likely contribute to increased ASCVD risk.

SUMMARY

Our understanding of mechanisms of elevated ASCVD risk in HIV continues to evolve, and the optimal treatment for CVD in HIV aside from targeting traditional risk factors remains unknown. Future studies including novel therapies to lower inflammation, control of risk factors, and implementation science are needed to ascertain optimal ways to treat and prevent ASCVD among PLWH.

Implementation of Cholesterol-Lowering Therapy to Reduce Cardiovascular Risk in Persons Living with HIV

The widespread availability of highly effective antiretroviral therapies has reduced mortality from opportunistic infections in persons living with HIV (PLHIV), resulting in an increase in atherosclerotic cardiovascular disease (ASCVD) and other chronic illnesses (Samji et al. 2013). Although there has been a decline in morbidity and mortality from ASCVD in the past several decades, contemporary studies continue to report higher rates of cardiovascular events (Rosenson et al. 2020). HIV has been identified as a risk enhancer for ASCVD by multiple professional guideline writing committees (Grundy Scott et al. 2019, Mach et al. 2020); however, the utilization of cholesterol-lowering therapies in PLHIV remains low (Rosenson et al. 2018). Moreover, the use of statin therapy in PLHIV is complicated by drug-drug interactions that may either elevate or lower the blood statin concentrations resulting in increased toxicity or reduced efficacy respectively. Other comorbidities commonly associated with HIV present other challenges for the use of cholesterol-lowering therapies. This review will summarize the data on lipoprotein-associated ASCVD risk in PLHIV and discuss the challenges with effective treatment. Finally, we present a clinical algorithm to optimize cardiovascular risk reduction in this high-risk population.

Switching from Tenofovir Disoproxil Fumarate to Tenofovir Alafenamide Significantly Worsens the Lipid Profile in a Real-World Setting

Tenofovir disoproxil fumarate (TDF) has increasingly been replaced by tenofovir alafenamide (TAF) because of reduced kidney and bone toxicity with TAF. This switch has, however, caused worsening of lipid concentrations in clinical trials, but data from any real-world setting are scarce. The objective of this study was to characterize the effect of TDF to TAF switch on plasma lipid concentrations in a real-world clinic population. This is a retrospective study comparing lipid concentrations and other laboratory parameters between the last visit on TDF and the first visit after at least a 2-month exposure to TAF. A total of 490 HIV-positive subjects were included in the study. The median (interquartile range) increase was 23.2 (0-38.7) mg/dL in total cholesterol (p < 0.001) and 15.5 (0-30.9) mg/dL in low-density lipoprotein (LDL) cholesterol (p < 0.001). The ratio of total cholesterol to high-density lipoprotein (HDL) cholesterol increased by 0.2 (-0.2 to 0.6), p < 0.001. The proportion of patients having optimal LDL cholesterol concentration by National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) decreased from 30.8% to 17.8% and proportion having dyslipidemia or severe dyslipidemia increased from 30.2% to 50.3% after the switch. Demographic characteristics, antiretroviral agents, or comedication did not affect the changes in lipid concentrations. Plasma creatinine decreased by 0.03 (-0.09 to 0.03) mg/dL (p < 0.001) and estimated glomerular filtration rate increased by 0.5 (-2.3 to 3.2) mL/min (p = 0.009). Switching from TDF to TAF caused a statistically significant worsening of the lipid profile that may have clinical relevance. The benefit of the lipid-lowering effect of TDF should be considered in selected patients with low risk for kidney and bone toxicity.

HIV infection and coronary heart disease: mechanisms and management

Antiretroviral therapy has largely transformed HIV infection into a chronic disease condition. As such, physicians and other providers caring for individuals living with HIV infection need to be aware of the potential cardiovascular complications of HIV infection and the nuances of how HIV infection increases the risk of cardiovascular diseases, including acute myocardial infarction, stroke, peripheral artery disease, heart failure and sudden cardiac death, as well as how to select available therapies to reduce this risk. In this Review, we discuss the epidemiology and clinical features of cardiovascular disease, with a focus on coronary heart disease, in the setting of HIV infection, which includes a substantially increased risk of myocardial infarction even when the HIV infection is well controlled. We also discuss the mechanisms underlying HIV-associated atherosclerotic cardiovascular disease, such as the high rates of traditional cardiovascular risk factors in patients with HIV infection and HIV-related factors, including the use of antiretroviral therapy and chronic inflammation in the setting of effectively treated HIV infection. Finally, we highlight available therapeutic strategies, as well as approaches under investigation, to reduce the risk of cardiovascular disease and lower inflammation in patients with HIV infection.

Current pharmacotherapy for the treatment of dyslipidemia associated with HIV infection

Introduction: Cardiovascular disease is an important cause of morbidity and mortality in persons with human immunodeficiency virus (PWH). The risk of atherosclerotic cardiovascular disease (ASCVD) is higher in PWH compared to uninfected persons. Dyslipidemia is a critical link in the pathogenesis of ASCVD in PWH. Chronic inflammation associated with HIV infection may drive both dyslipidemia and ASCVD. Areas covered: The authors review the evidence for using lipid-lowering therapy in PWH and includes an overview of the utility and complexity of using statins in PWH, in particular, drug interactions, safety, and efficacy. In addition, data covering alternate therapies like omega-3 fatty acids, fibrates, niacin, ezetimibe, and PCSK-9 inhibitors are reviewed. Expert opinion: Dyslipidemia is a common problem in PWH. The risk of ASCVD is higher in PWH. Lipid-lowering therapy reduces the risk of ASCVD, but clinical endpoint trials are lacking in PWH. Statin therapy is the mainstay of primary prevention for ASCVD. The timing of when to initiate primary prevention with statins in PWH is unclear. Beyond statins, there are limited data that other lipid-lowering agents have utility in PWH. Ongoing trials like the REPRIEVE trial will inform the community about the optimal approach to lipid-lowering therapy in PWH.

Expanding the activity spectrum of antiviral agents

Broad-spectrum antivirals (BSAs) are agents that inhibit replication of several human viruses. Here, we review 108 approved, investigational, and experimental BSAs, for which safety profiles in humans are available. The most effective and tolerable BSAs could reinforce the arsenal of available antiviral therapeutics pending the results of further pre-clinical and clinical studies.

Lipid Abnormalities in Persons Living With HIV Infection

Lipid abnormalities are prevalent among persons living with HIV infection and contribute to increasing the risk of cardiovascular events. Antiretroviral therapy (ART) is associated with lipid abnormalities, most commonly hypertriglyceridemia, but also increases in low-density lipoprotein cholesterol and total cholesterol. Different classes of ART, and different drugs within classes, have differing effects on lipid levels, but in general newer drugs have more favourable effects compared with older ones. Low-level inflammation and chronic immune activation act on lipids through a variety of mechanisms to make them more atherogenic. As a consequence, risk is higher than would be expected for any given cholesterol level. Clinical outcome trials of cholesterol-lowering therapies have not yet been completed in people living with HIV, so that treatment decisions depend on extrapolation from studies in uninfected populations. Traditional risk assessment tools underestimate cardiovascular risk in individuals with HIV. Statins are the mainstay of lipid-lowering drug treatment; however, drug-drug interactions with ART must be considered. Simvastatin and lovastatin are contraindicated in patients taking protease inhibitors, and the dose of atorvastatin and rosuvastatin should be limited to 40 mg and 10 mg/d with some ART combinations. Switching from older forms of ART to lipid-friendly newer ones is a useful strategy as long as virologic suppression is maintained, but adding a statin lowers low-density lipoprotein cholesterol more effectively. Studies indicate that lipid abnormalities are not treated as aggressively in individuals living with HIV as they are in uninfected people, making this an opportunity to improve care.

Dysregulation of Neuronal Cholesterol Homeostasis upon Exposure to HIV-1 Tat and Cocaine Revealed by RNA-Sequencing

HIV-1 Tat protein is released from HIV-1-infected cells and can enter non-permissive cells including neurons. Tat disrupts neuronal homeostasis and may contribute to the neuropathogenesis in people living with HIV (PLWH). The use of cocaine by PLWH exacerbates neuronal dysfunction. Here, we examined the mechanisms by which Tat and cocaine facilitate alterations in neuronal homeostatic processes. Bioinformatic interrogation of the results from RNA deep sequencing of rat hippocampal neurons exposed to Tat alone indicated the dysregulation of several genes involved in lipid and cholesterol metabolism. Following exposure to Tat and cocaine, the activation of cholesterol biosynthesis genes led to increased levels of free cholesterol and cholesteryl esters in rat neurons. Results from lipid metabolism arrays validated upregulation of several processes implicated in the biogenesis of β-amyloid and Alzheimer’s disease (AD), including sterol o-acyltransferase 1/acetyl-coenzyme A acyltransferase 1 (SOAT1/ACAT1), sortilin-related receptor L1 (SORL1) and low-density lipoprotein receptor-related protein 12 (LRP12). Further studies in Tat-treated primary neuronal cultures and brain tissues from HIV-1 transgenic mice as well as SIV-infected macaques confirmed elevated levels of SOAT1/ACAT 1 proteins. Our results offer novel insights into the molecular events involved in HIV and cocaine-mediated neuronal dysfunction that may also contribute to neuropathogenic events associated with the development of AD.

Short-Term Efficacy and Safety of Adding Ezetimibe to Current Regimen of Lipid-Lowering Drugs in Human Immunodeficiency Virus-Infected Thai Patients Treated with Protease Inhibitors

Long-term complications of protease inhibitor (PI) treatment includes increased cardiovascular risks due to dyslipidemia in patients infected with human immunodeficiency virus (HIV). Ezetimibe reduces low-density lipoprotein cholesterol (LDL-C) without drug interactions with PIs and statins. Furthermore, the addition of ezetimibe to statins is an optional treatment in HIV-infected patients with uncontrolled dyslipidemia. The objective of this study was to determine the short-term efficacy and safety of adding ezetimibe to the currently administered statin regimen. Thirty-two patients received ezetimibe (10 mg daily) in addition to their ongoing lipid-lowering therapy for 18 weeks. Serum LDL-C, total cholesterol (TC), triglycerides (TGs), TC/high-density lipoprotein cholesterol (HDL-C) ratio, and HDL-C were measured at baseline, and weeks 6, 12, and 18. Safety parameters were assessed by adverse event reports and laboratory assessments throughout the study. The mean percent change from baseline to endpoint in LDL-C, TC, TGs, and TC/HDL-C ratio were -23.3% (p<0.001), -15.0% (p=0.001), -22.1% (p=0.004), and -16.2% (p=0.018), respectively. No adverse event or other abnormal laboratory results occurred. Addition of ezetimibe to currently administered lipid-lowering drugs in HIV-infected patients receiving PIs with uncontrolled dyslipidemia demonstrated significantly improved efficacy in reducing their LDL-C, TC, TGs, and TC/HDL-C ratio levels. Moreover, this therapy was safe and well-tolerated.

Novel activities of safe-in-human broad-spectrum antiviral agents

According to the WHO, there is an urgent need for better control of viral diseases. Re-positioning existing safe-in-human antiviral agents from one viral disease to another could play a pivotal role in this process. Here, we reviewed all approved, investigational and experimental antiviral agents, which are safe in man, and identified 59 compounds that target at least three viral diseases. We tested 55 of these compounds against eight different RNA and DNA viruses. We found novel activities for dalbavancin against echovirus 1, ezetimibe against human immunodeficiency virus 1 and Zika virus, as well as azacitidine, cyclosporine, minocycline, oritavancin and ritonavir against Rift valley fever virus. Thus, the spectrum of antiviral activities of existing antiviral agents could be expanded towards other viral diseases.

•

339 approved, investigational and experimental safe-in-human antivirals were identified.

•

59 compounds, which target ≥3 viral diseases, were selected.

•

55 of the 59 compounds were tested against 8 RNA and DNA viruses.

•

7 compounds were found to possess novel antiviral activities.

Cardiovascular risk and dyslipidemia among persons living with HIV: a review

BACKGROUND

Aim of this review is to focus the attention on people living with HIV infection at risk of developing a cardiovascular event. What is or what would be the most suitable antiretroviral therapy? Which statin or fibrate to reduce the risk? How to influence behavior and lifestyles?

DISCUSSION

Prevention of cardiovascular disease (CVD) risk remains the first and essential step in a medical intervention on these patients. The lifestyle modification, including smoking cessation, increased physical activity, weight reduction, and the education on healthy dietary practices are the main instruments. Statins are the cornerstone for the treatment of hypercholesterolemia. They have been shown to slow the progression or promote regression of coronary plaque, and could also exert an anti-inflammatory and immunomodulatory effect. However the current guidelines for the use of these drugs in general population are dissimilar, with important differences between American and European ones. The debate between American and European guidelines is still open and, also considering the independent risk factor represented by HIV, specific guidelines are warranted. Ezetimibe reduces the intestinal absorption of cholesterol. It is effective alone or in combination with rosuvastatin. It does not modify plasmatic concentrations of antiretrovirals. A number of experimental new classes of drugs for the treatment of hypercholesterolemia are being studied. Fibrates represent the first choice for treatment of hypertriglyceridemia, however, the renal toxicity of fibrates and statins should be considered. Omega 3 fatty acids have a good safety profile, but their efficacy is limited. Another concern is the high dose needed. Other drugs are acipimox and tesamorelin. Current antiretroviral therapies are less toxic and more effective than regimens used in the early years. Lipodistrophy and dyslipidemia are the main causes of long-term toxicities. Not all antiretrovirals have similar toxicities. Protease Inhibitors may cause dyslipidemia and lipodystrophy, while integrase inhibitors have a minimal impact on lipids profile, and no evidence of lipodystrophy. There is still much to be written with the introduction of new drugs in clinical practice.

CONCLUSIONS

Cardiovascular risk among HIV infected patients, interventions on behavior and lifestyles, use of drugs to reduce the risk, and switch in antiretroviral therapy, remain nowadays major issues in the management of HIV-infected patients.

Ezetimibe: an update on its clinical usefulness in specific patient groups

The aim of pharmacological lipid modification is to reduce low-density lipoprotein cholesterol (LDL-C) as a means of either secondary or primary prevention of cardiovascular disease. Statins are the first-line therapy for pharmacological lipid modification. Ezetimibe is a drug which reduces LDL-C by selectively inhibiting intestinal cholesterol absorption. This provides an alternative pharmacological approach to that of statin therapy to reduce LDL-C. Ezetimibe has been shown to significantly reduce levels of LDL-C and recently, as demonstrated in the IMPROVE-IT trial, to reduce the rate of cardiovascular events in high-risk patients. Ezetimibe therefore has an important role in pharmacological lipid modification. In this paper, we examine the body of research behind ezetimibe and assess its current clinical applications in different patient subgroups.

Drug therapies for HIV-related metabolic disorders

INTRODUCTION

Human immunodeficiency virus (HIV) has become a chronic disease often associated with dyslipidaemia and insulin resistance. Combination antiretroviral therapy (cART) may contribute to metabolic disturbances, eventually leading to increased cardiovascular disease (CVR) in this population. Escalating interventions to decrease CVR include promoting a healthy lifestyle, such as quitting smoking, diet and regular exercise. If they do not achieve the goals, a change of cART should be considered, followed by or used concomitantly with the use of chemical therapies.

AREAS COVERED

The aim of this article is to review the available drug therapies for the treatment of metabolic disorders in HIV-infected patients and to examine their safety and effectiveness in this population. A review of the literature was conducted, highlighting the most relevant articles.

EXPERT OPINION

Switching strategies can be useful but its expected benefit is not high. Therefore, chemical intervention is often needed. Statins have been proven to reduce CVR in the general population and in HIV-infected patients. Simvastatin is contraindicated in patients treated with boosted PI due to interactions; atorvastatin is safe at submaximal dose and needs close monitoring, while pravastatin lacks lipid-lowering potency, and rosuvastatin and pitavastatin are safe. Ezetimibe and fibrates are also safe and effective in HIV-infected patients and can be used in combination with statins. The management of glucose homeostatic disorders in HIV-infected patients follows the same guidelines as in the general population. However, there are specific considerations with respect to the interactions of particular medications with cART. When drug therapy is needed, metformin is the first-line drug. Decisions regarding second- and third-line drugs should be carefully individualized.

HIV Infection and Primary Prevention of Cardiovascular Disease: Lights and Shadows in the HAART Era

With the progressive increase in life-expectancy of human immunodeficiency virus (HIV)-positive patients in the "highly active antiretroviral therapy" (HAART) era, co-morbidities, particularly cardiovascular (CV) diseases (CVD) are emerging as an important concern. The pathophysiology of CVD in this population is complex, due to the interaction of classical CV risk factors, viral infection and the effects of antiretroviral therapy (ARV). The role of ARV drugs in HIV is double edged. While these drugs reduce systemic inflammation, an important factor in CV development, they may at the same time be proatherogenic by inducing dyslipidemia, body fat redistribution and insulin resistance. In these patients primary prevention is challenging, considering the lower median age at which acute coronary syndromes occur. Furthermore prevention is still limited by the lack of robust evidence-based, HIV-specific recommendations. Therefore we performed a comprehensive evaluation of the literature to analyze current knowledge on CVD prevalence in HIV-infected patients, traditional and HIV-specific risk factors and risk stratification, and to summarize the recommendations for primary prevention of CVD in this HIV population.

Novel functions of PXR in cardiometabolic disease

Cardiometabolic disease emerges as a worldwide epidemic and there is urgent need to understand the molecular mechanisms underlying this chronic disease. The chemical environment to which we are exposed has significantly changed in the past few decades and recent research has implicated its contribution to the development of many chronic human diseases. However, the mechanisms of how exposure to chemicals contributes to the development of cardiometabolic disease are poorly understood. Numerous chemicals have been identified as ligands for the pregnane X receptor (PXR), a nuclear receptor functioning as a xenobiotic sensor to coordinately regulate xenobiotic metabolism via transcriptional regulation of xenobiotic-detoxifying enzymes and transporters. In the past decade, the function of PXR in the regulation of xenobiotic metabolism has been extensively studied by many laboratories and the role of PXR as a xenobiotic sensor has been well-established. The identification of PXR as a xenobiotic sensor has provided an important tool for the study of new mechanisms through which xenobiotic exposure impacts human chronic diseases. Recent studies have revealed novel and unexpected roles of PXR in modulating obesity, insulin sensitivity, lipid homeostasis, atherogenesis, and vascular functions. These studies suggest that PXR signaling may contribute significantly to the pathophysiological effects of many known xenobiotics on cardiometabolic disease in humans. The discovery of novel functions of PXR in cardiometabolic disease not only contributes to our understanding of "gene-environment interactions" in predisposing individuals to chronic diseases but also provides strong evidence to inform future risk assessment for relevant chemicals. This article is part of a Special Issue entitled: Xenobiotic nuclear receptors: New Tricks for An Old Dog, edited by Dr. Wen Xie.

Clinical management of dyslipidaemia associated with combination antiretroviral therapy in HIV-infected patients

The introduction of potent combination antiretroviral therapy (cART) has had a remarkable impact on the natural history of HIV infection, leading to a dramatic decline in the mortality rate and a considerable increase in the life expectancy of HIV-positive people. However, cART use is frequently associated with several metabolic complications, mostly represented by lipid metabolism alterations, which are reported very frequently among persons treated with antiretroviral agents. In particular, hyperlipidaemia occurs in up to 70%-80% of HIV-positive subjects receiving cART and is mainly associated with specific antiretroviral drugs belonging to three classes of antiretroviral agents: NRTIs, NNRTIs and PIs. The potential long-term consequences of cART-associated dyslipidaemia are not completely understood, but an increased risk of premature coronary heart disease has been reported in HIV-infected patients on cART, so prompt correction of lipid metabolism abnormalities is mandatory in this population. Dietary changes, regular aerobic exercise and switching to a different antiretroviral regimen associated with a more favourable metabolic profile are the first steps in clinical management, but lipid-lowering therapy with fibrates or statins is often required. In this case, the choice of hypolipidaemic drugs should take into account the potential pharmacokinetic interactions with many antiretroviral agents.

Impact of antiretroviral therapy on lipid metabolism of human immunodeficiency virus-infected patients: Old and new drugs

For human immunodeficiency virus (HIV)-infected patients, the 1990s were marked by the introduction of highly active antiretroviral therapy (HAART) representing a new perspective of life for these patients. The use of HAART was shown to effectively suppress the replication of HIV-1 and dramatically reduce mortality and morbidity, which led to a better and longer quality of life for HIV-1-infected patients. Apart from the substantial benefits that result from the use of various HAART regimens, laboratory and clinical experience has shown that HAART can induce severe and considerable adverse effects related to metabolic complications of lipid metabolism, characterized by signs of lipodystrophy, insulin resistance, central adiposity, dyslipidemia, increased risk of cardiovascular disease and even an increased risk of atherosclerosis. New drugs are being studied, new therapeutic strategies are being implemented, and the use of statins, fibrates, and inhibitors of intestinal cholesterol absorption have been effective alternatives. Changes in diet and lifestyle have also shown satisfactory results.

Epidemiology and management of antiretroviral-associated cardiovascular disease

Risk and manifestations of cardiovascular disease (CVD) in patients infected with human immunodeficiency virus (HIV) will continue to evolve as improved treatments and life expectancy of these patients increases. Although initiation of antiretroviral (ARV) therapy has been shown to reduce this risk, some ARV medications may induce metabolic abnormalities, further compounding the risk of CVD. In this patient population, both pharmacologic and nonpharmacologic strategies should be employed to treat and reduce further risk of CVD. This review summarizes epidemiology data of the risk factors and development of CVD in HIV and provides recommendations to manage CVD in HIV-infected patients.

Cardiovascular disease in human immunodeficiency virus

With widespread access to high-quality medical care as in Australia, human immunodeficiency virus (HIV) is now considered a chronic, treatable condition, with a good life expectancy. The use of combined highly active antiretroviral therapy has enabled effective suppression of the virus, but has also been associated with increased cardiac morbidity and mortality. Over representation of traditional cardiac risk factors, such as hyperlipidaemia and diabetes, as well as an increased incidence of ischaemic and non-ischaemic heart disease is now considered a major concern of treatment with antiretroviral therapy. Therefore, a contemporary management strategy for patients with HIV must include active prevention and treatment of cardiovascular risk. This review will outline the complex interplay between HIV infection, antiretroviral drug regimens and accelerated cardiovascular disease, with a particular focus on screening, prevention and treatment options in a contemporary Australian HIV population.

Managing dyslipidemia in HIV/AIDS patients: challenges and solutions

Human immunodeficiency virus (HIV) is a chronic disease associated with dyslipidemia and insulin resistance. In addition, the administration of combination antiretroviral therapy is associated with an increase in the incidence of metabolic risk factors (insulin resistance, lipoatrophy, dyslipidemia, and abnormalities of fat distribution in HIV patients). HIV dyslipidemia is a common problem, and associated with an increase in incidence of cardiovascular disease. Further challenges in the management of HIV dyslipidemia are the presence of diabetes and metabolic syndrome, nonalcoholic fatty liver disease, hypothyroidism, chronic kidney disease, the risk of diabetes associated with statin administration, age and ethnicity, and early menopause in females. Dyslipidemia in patients with HIV is different from the normal population, due to the fact that HIV increases insulin resistance and HIV treatment not only may induce dyslipidemia but also may interact with lipid-lowering medication. The use of all statins (apart from simvastatin and lovastatin) is safe and effective in HIV dyslipidemia, and the addition of ezetimibe, fenofibrate, fish oil, and niacin can be used in statin-unresponsive HIV dyslipidemia. The management of dyslipidemia and cardiovascular disease risks associated with HIV is complex, and a certain number of patients may require management in specialist clinics run by specialist physicians in lipid disorders. Future research is needed to address best strategies in the management of hyperlipidemia with HIV infection.

Effects of ezetimibe on cholesterol metabolism in HIV-infected patients with protease inhibitor-associated dyslipidemia: a single-arm intervention trial

Background

The effects of ezetimibe on cholesterol metabolism in HIV-infected patients receiving boosted protease inhibitors have not been thoroughly assessed. The aim of this study was to assess cholesterol homeostasis in patients with PI associated dyslipidemia and its relationship with the response to treatment with the cholesterol-absorption inhibitor ezetimibe.

Methods

Fifteen patients with ritonavir-boosted PI-containig therapy and LDL-cholesterol > 3.36 mmol/L (>130 mg/dL) were assessed at baseline and after an 8-week course of ezetimibe 10 mg/d. Serum non-cholesterol sterols were measured at each visit as markers of cholesterol synthesis and absorption. Total-, LDL-, and HDL-cholesterol triglycerides, apolipoproteins A1 and B, high sensitivity C-reactive protein, CD4 cells and HIV-1 RNA were also measured.

Results

Ezetimibe treatment was well tolerated in all patients and resulted in significant reductions in total cholesterol (-11.4%, p = .002), LDL-cholesterol (-20.4%, p = .003), non-HDL-cholesterol (-13.4%, p = .002) and apolipoprotein B (-9.1%, p = .021).

Treatment with ezetimibe was associated with decreased cholesterol absorption markers (campesterol-to-cholesterol ratio -43.0%, p = .001; sitosterol-to-cholesterol ratio -41.9%, p = .001) and increased synthesis markers (lathosterol-to-cholesterol ratio 53.2%, p = .005). Baseline absorption or synthesis markers were unrelated to the response to treatment. CD4 cell count and plasma HIV-1 RNA remained unchanged.

Conclusions

The level of cholesterol absorption or synthesis does not appear to be a major determinant of the responsiveness to ezetimibe in patients on ritonavir-boosted PI-containing therapy.

Trial registration

EudraCT: 2006-006156-36

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2334-14-497) contains supplementary material, which is available to authorized users.

Dyslipidemia in HIV-positive patients: a randomized, controlled, prospective study on ezetimibe+fenofibrate versus pravastatin monotherapy

Introduction

We designed a randomized, controlled prospective study aimed at comparing efficacy and tolerability of ezetimibe+fenofibrate treatment versus pravastatin monotherapy in dyslipidemic HIV-positive (HIV+) patients treated with protease inhibitors (PIs).

Methods

We consecutively enrolled 42 HIV+ dyslipidemic patients on stable PIs therapy (LDL cholesterol >130 mg/dl or triglycerides 200–500 mg/dl with non-HDL cholesterol >160 mg/dl). After basal evaluation, patients were randomized to a six-month treatment with ezetimibe 10 mg/day+fenofibrate 200 mg/day or with pravastatin 40 mg/day. Both at the basal evaluation and after the six-month treatment, the patients underwent blood tests for lipid parameters, and muscle and liver enzymes.

Results

At baseline, the two groups (21 patients each) were similar with regards to gender, age, BMI, blood pressure and virologic and metabolic parameters. After the six-month therapy, total cholesterol, LDL cholesterol and non-HDL cholesterol decreased significantly (p<0.01) in both groups. high-density lipoprotein (HDL) cholesterol increased (44±10 to 53±12 mg/dl, p<0.005) and triglycerides decreased (from 265±118 mg/dl to 149±37 mg/dl, p<0.001) in the ezetimibe+fenofibrate group, whereas both parameters remained unchanged in the pravastatin group. Mean values of creatine kinase (CK), alanine aminotransferase and aspartate aminotransferase were unchanged in both groups; only one patient in the pravastatin group stopped the treatment after two months, due to increased CK.

Conclusions

In dyslipidemic HIV+ patients on PI therapy, the association of ezetimibe+fenofibrate is more effective than pravastatin monotherapy in improving lipid profile and is also well tolerated.

Insulin resistance, lipodystrophy and cardiometabolic syndrome in HIV/AIDS

HIV associated insulin resistance, lipodistrophy and cardiometabolic syndrome have been extensively studied and continue to be the scope of much research. There is compelling evidence that both the HIV itself and the therapeutical regimes are major contributors to all of these associated comorbidities. HIV has increasingly been recognized as a disease of accelerated aging, manifested by increased progression of vascular disease and cellular markers of aging. The antiretroviral medication can increase insulin resistance and cause lipotoxocity and HIV-associated lipodystrophy leading to cardiovascular pathology. In this article we review the pathogenesis, management, and prevention of the long-term complications of HIV and its therapies, including cardiovascular disease, lipodystrophy, and insulin resistance along with the growing focus on biomarkers to predict development of end-organ disease. Through a focused literature search we review the established evidence, the developing research about the treatment strategies in treated HIV infection as well as identify potential areas for future research.

Impact of efavirenz on intestinal metabolism and transport: insights from an interaction study with ezetimibe in healthy volunteers

Hypercholesterolemia frequently occurs in patients treated with efavirenz who cannot be treated adequately with statins because of drug interactions. These patients may benefit from cholesterol-lowering therapy with ezetimibe. This study determined the influence of single-dose and multiple-dose efavirenz (400 mg/day for 9 days) on the pharmacokinetics and sterol-lowering of ezetimibe (10 mg) in 12 healthy subjects. In addition, the influence of efavirenz on genome-wide intestinal expression and in vitro function of ABCB1, ABCC2, UGT1A1, and OATP1B1 was studied. Efavirenz (multiple dose) had no influence on the pharmacokinetics and lipid-lowering functions of ezetimibe. Intestinal expression of enzymes and transporters (e.g., ABCB1, ABCC2, and UGT1A1) was not affected by chronic efavirenz. Efavirenz (single dose) slightly increased ezetimibe absorption and markedly decreased exposure to ezetimibe-glucuronide (single dose and multiple dose), which may be explained by inhibition of UGT1A1 and ABCB1 (in vitro data). Ezetimibe had no effect on the disposition of efavirenz. Consequently, ezetimibe may be a safe and efficient therapeutic option in patients with HIV infection.

Management of dyslipidemia in HIV-infected patients

Antiretroviral therapy has dramatically increased survival for HIV-infected individuals. As this population lives longer, coronary heart disease has become an important comorbid condition. Dyslipidemia in HIV-infected individuals is a complex condition, with multiple contributing factors including the HIV virus itself, individual genetic characteristics and antiretroviral therapy-induced metabolic changes. Effective management of dyslipidemia in this population is essential to reduce cardiovascular risk but presents multiple challenges due to interactions between antiretroviral therapy agents and lipid-lowering medications.

Cardiovascular implications of HIV-induced dyslipidemia

Cardiovascular disease (CVD) is currently the second most frequent cause of death (after cancer) among HIV-positive subjects. The clinical use of highly active antiretroviral therapy (HAART) has dramatically reduced mortality and morbidity in HIV-positive population, leading to prolonged and improved quality of life. However, as mortality and morbidity from AIDS-related conditions improve, CVD assumes increasing magnitude. It is estimated that by 2015 more than 50% of HIV-positive patients will be older than 50 years. Since age is a major unmodifiable cardiovascular risk factor, the risk for CVD in this population will significantly and progressively increase in the near future. A large part of the risk for cardiovascular events appears to be a result of lipid abnormalities characterizing HIV-positive persons. This review focuses on HIV-associated lipid abnormalities and CVD. Lipid abnormalities may be related to either viral infection, HAART or both. Dyslipidemia characterizing HIV-infected patients has become a therapeutic target to reduce cardiovascular risk of HIV-treated patients. HAART-treated patients show an atherogenic lipid profile comprised of low HDL-cholesterol levels, hypertrigliceridemia and increased levels of small-LDL particles. Current guidelines for the treatment of dyslipidemia and reducing cardiovascular risk in HIV-positive patients suggest that when lifestyle modifications (i.e., diet and exercise) and switching antiretroviral therapy are not enough, statins should be the first-line therapy for dyslipidemia. HDL raising interventions (niacin and fibrates) should be considered to raise HDL levels and lower triglyceride in HIV-infected patients. Implications of lipid-related interventions in HIV-treated patients to avoid drug interactions and their adverse effects are also discussed.

Approach to dyslipidemia, lipodystrophy, and cardiovascular risk in patients with HIV infection

There is a significant prevalence (20%–80% depending on the population and the study) of lipid disorders and other cardiovascular risk factors in people living with HIV infection. This review focuses on HIV and HIV treatment–associated metabolic and cardiovascular concerns, including dyslipidemias, lipodystrophy syndromes, endothelial dysfunctions, and associated metabolic events such as insulin resistance. Emerging hypotheses of the underlying pathophysiology of these issues, with impact on selection of specific antiretroviral treatment (ART) strategies, therapy, and preventive approaches to decreasing cardiovascular risk and other problems associated with these syndromes are discussed. Screening for cardiovascular risk as part of the decision of starting antiretroviral therapy, and during care of patients with HIV regardless of ART therapy status, is suggested with particular areas of focus. Statins, other hyperlipidemic therapies, treatment for specific problems arising due to lipodystrophy, and implications on ART selection to avoid drug interactions and adverse effects are also discussed.

Dyslipidemia and lipid management in HIV-infected patients

PURPOSE OF REVIEW

Dyslipidemia is highly prevalent among patients living with chronic HIV infection and may confer increased risk of cardiovascular disease in this patient population. This review summarizes recent data investigating lipid abnormalities and its management in HIV-infected patients.

RECENT FINDINGS

Studies in the last year have evaluated the effects of various lipid-lowering therapies not previously investigated in the HIV patient population. Rosuvastatin is a potent statin that appears to be well tolerated and effective in HIV-infected patients with hypercholesterolemia.

SUMMARY

Dyslipidemia is common in HIV-infected individuals. Medical therapy of lipid disorders needs to take potential drug-drug interactions of lipid-lowering medications and antiretroviral agents into consideration.

HIV and HAART-Associated Dyslipidemia

Effective highly active antiretroviral therapy (HAART) for human immunodeficiency virus-1 (HIV) infection has led to marked improvement in life-expectancy for those infected with HIV. Despite reductions in the incidence of AIDS with effective treatment, patients continue to experience considerable morbidity and mortality from non-AIDS illness such as premature cardiovascular disease, liver failure and renal failure. These morbidities, particularly premature cardiovascular disease, are thought to be related to a combination of the effects of an ageing HIV-infected population coupled with long-term effects of HIV infection and antiretroviral therapy (ART). One of the principle drivers behind the well documented increase in the risk of cardiovascular disease in HIV-infected patients is dyslipidemia.

This review will focus on the clinical presentation of HIV and ART-associated dyslipidemia, what is known of its patho-physiology, including associations with use of specific antiretroviral medications, and suggest screening and management strategies.

Dyslipidemia and its Treatment in HIV Infection

HIV-infected patients have metabolic abnormalities that put them at increased risk of cardiovascular disease (CVD), including abnormalities associated with HIV infection itself, antiretroviral treatment, restoration to health, and body composition changes. The 2 major components of dyslipidemia in HIV-infected patients are hypertriglyceridemia and reduction in high-density lipoprotein (HDL) cholesterol (with likely altered function of HDL cholesterol); these abnormalities contribute to increased atherosclerotic risk. Adverse effects of antiretroviral drugs on lipids are not class specific but rather are associated with particular drugs. Thus, practitioners need to be cognizant of the risks of metabolic abnormalities posed by individual drugs. HIV infection increases CVD risk independent of the effects of traditional risk factors. The relative risk of CVD in HIV-infected patients has decreased in recent years with increasing use of lipid-lowering therapy. However, use of lipid-lowering therapy is complicated by numerous potential drug interactions with antiretroviral drugs that practitioners need to consider when prescribing lipid-lowering therapy. This article summarizes a presentation made by Carl Grunfeld, MD, PhD, at the International AIDS Society-USA continuing medical education program in Los Angeles in March 2010. The original presentation is available as a Webcast at www.iasusa.org.

Short-term ezetimibe is well tolerated and effective in combination with statin therapy to treat elevated LDL cholesterol in HIV-infected patients

BACKGROUND

Ezetimibe inhibits intestinal absorption of cholesterol.

METHODS

Multicentered double-blind, randomized, placebo-controlled, crossover study to determine the short-term safety, efficacy, and tolerability of ezetimibe in combination with ongoing statin therapy in HIV-infected adults with elevated low-density lipoprotein cholesterol (LDL-C). Participants on stable HAART with fasting LDL-C at least 130 mg/dl and stable statin were randomized to ezetimibe 10 mg daily or placebo for 12 weeks followed by 4 weeks of washout and then 12 weeks with alternative study assignment. Percentage and absolute change in LDL-C (primary endpoint), total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-C), apolipoprotein B, and high sensitivity C-reactive protein were compared. Changes in clinical symptoms and safety laboratory measurements were assessed.

RESULTS

Forty-four participants enrolled: 70% men, median age 49 years, 43% White/Non-Hispanic, median CD4 cell count 547 cells/microl, and 95% HIV RNA less than 50 copies/ml. Median (interquartile range) percentage change in LDL-C was -20.8% (-25.4, -10.7) with ezetimibe and -0.7% (-10.3,18.6) with placebo; the median within-participant effect of ezetimibe was -14.1% (-33.0, -5.0; P < 0.0001). Median difference in absolute LDL-C values between ezetimibe and placebo was -32 mg/dl (-58, -6, P < 0.0001). Significant differences in within-participant effect of ezetimibe were noted for total cholesterol -18.60% (-27.22, -11.67, P < 0.001), non-HDL-C -23.18% (-33.14, -14.36, P < 0.0001), and apolipoprotein B -8.73% (-18.75, 1.99, P = 0.02). No significant changes seen in HDL-C, triglyceride, or high sensitivity C-reactive protein. Ezetimibe was well tolerated. Adverse events were similar between phases.

CONCLUSION

The present short-term study found adding ezetimibe to ongoing statin therapy was well tolerated and effective in reducing LDL-C, total cholesterol, non-HDL-C, and apolipoprotein B. Adding ezetimibe to statin therapy offers reasonable treatment option for HIV-infected patients with elevated LDL-C.