Efficacy and tolerability of pravastatin for the treatment of HIV-1 protease inhibitor-associated hyperlipidaemia: a pilot study

A Systematic Review and Meta-Analysis on the Impact of Statin Treatment in HIV Patients on Antiretroviral Therapy

The rate of new human immunodeficiency virus (HIV) infections globally is alarming. Although antiretroviral therapy (ART) improves the quality of life among this group of patients, ARTs are associated with risk of cardiovascular diseases (CVD). Moreover, virally suppressed patients still experience immune activation associated with HIV migration from reservoir sites. Statins are widely recommended as therapeutic agents to control ART-related CVD; however, their impacts on the cluster of differentiation (CD)4 count and viral load are inconsistent. To assess the effect of statins on markers of HIV infections, immune activation and cholesterol, we thoroughly reviewed evidence from randomised controlled trials. We found 20 relevant trials from three databases with 1802 people living with HIV (PLHIV) on statin-placebo treatment. Our evidence showed no significant effect on CD4 T-cell count standardised mean difference (SMD): (-0.59, 95% confidence intervals (CI): (-1.38, 0.19), p = 0.14) following statin intervention in PLHIV on ART. We also found no significant difference in baseline CD4 T-cell count (SD: (-0.01, 95%CI: (-0.25, 0.23), p = 0.95). Our findings revealed no significant association between statins and risk of viral rebound in PLHIV with undetectable viral load risk ratio (RR): (1.01, 95% CI: (0.98, 1.04), p = 0.65). Additionally, we found a significant increase in CD8⁺CD38⁺HLA-DR⁺ T-cells (SMD (1.10, 95% CI: (0.93, 1.28), p < 0.00001) and CD4⁺CD38⁺HLA-DR⁺ T-cells (SMD (0.92, 95% CI: (0.32, 1.52), p = 0.003). Finally, compared to placebo, statins significantly reduced total cholesterol (SMD: (-2.87, 95% CI: (-4.08, -1.65), p < 0.0001)). Our results suggest that the statin lipid-lowering effect in PLHIV on ART may elevate immune activation without influencing the viral load and CD4 count. However, due to the limited evidence synthesised in this meta-analysis, we recommend that future powered trials with sufficient sample sizes evaluate statins' effect on CD4 count and viral load, especially in virally suppressed patients.

Evidence-based review of statin use in patients with HIV on antiretroviral therapy

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Cardiovascular disease is up to two times more prevalent in patient with HIV.

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Based on pharmacokinetic and clinical data, atorvastatin and pravastatin are generally considered safe for HIV patients receiving ART.

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Rosuavstatin is generally safe if started at a low dose and a maximum 20 mg per day.

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Fluvastatin, lovastatin, and simvastatin should be avoided in patients with HIV receiving ART.

Introduction

As a result of improved safe and effective therapeutic options for human immunodeficiency virus (HIV), life expectancy of those living with HIV is increasing leading to new challenges (e.g., management of chronic diseases). Some chronic diseases (e.g., cardiovascular disease [CVD]), are up to two times more prevalent in patients with HIV. Statins are a mainstay of therapy for prevention of CVD; but, clinicians should be aware that not all statins are appropriate for use in the HIV population, especially those receiving antiretroviral therapy (ART). The purpose of this article is to review the pharmacokinetic and clinical data for statin therapy in HIV-infected patients receiving ART.

Methods

A systematic literature search using PubMed and MEDLINE databases was performed using each statin drug name combined with HIV, pharmacokinetics, AIDS, and/or human immunodeficiency virus. English language trials published from 1946 to November 2016 were considered, and results were limited to clinical efficacy trials.

Results

In general, atorvastatin and pravastatin are safe and effective for patients treated with protease-inhibitor (PI) or non-nucleoside reverse transcriptase inhibitor-based ART. Rosuvastatin is generally considered safe if started at a low dose, but should be avoided if possible in patients receiving PI-based ART. Pitavastatin has limited supporting evidence, but appears safe for use based on its pharmacokinetic properties and low number of drug interactions. Fluvastatin, lovastatin, and simvastatin should be avoided in patients receiving ART due to drug interactions, adverse events, and/or limited clinical data.

Conclusion

Clinicians need to be familiar with the intricacies of statin selection for the prevention of CVD in patients with HIV on ART.

Treatment of dyslipidemia in HIV

Patients infected with HIV have a high risk of developing dyslipidemia. Effective therapeutic strategies can be challenging due to an increase risk of drug interactions and other comorbidities. Understanding the underlying pathophysiology and the principles of pharmacological and non-pharmacological therapeutic interventions can be of value in the appropriate management of dyslipidemia in the HIV-infected patient.

Statin therapy decreases serum levels of high-sensitivity C-reactive protein and tumor necrosis factor-α in HIV-infected patients treated with ritonavir-boosted protease inhibitors

BACKGROUND

Statins are lipid-lowering drugs that exhibit anti-inflammatory and immune-modulatory properties, leading to a reduction of serum levels of C-reactive protein (CRP) in the general population.

OBJECTIVE

Because very limited data are available today, our objective was to assess the lipid-lowering effects of statins and their capacity to decrease selected soluble markers of inflammation in HIV-infected patients.

METHODS

Retrospective cohort study of HIV-infected adult patients with hypercholesterolemia who were receiving a stable antiretroviral regimen including a ritonavir-boosted protease inhibitor and who started a lipid-lowering therapy with rosuvastatin (10 mg daily), atorvastatin (10 mg daily), or pravastatin (40 mg daily) and were followed-up for at least 12 months. One hundred and fifty-one patients were enrolled in the study: 51 in the rosuvastatin group, 47 in the atorvastatin group, and 53 in the pravastatin group. The primary observation was change in plasma lipid levels and serum markers of inflammation (high-sensitivity C-reactive protein [hsCRP], interleukin-6 [IL-6], and tumor necrosis factor-α [TNF- α]), while secondary observations include immunovirological parameters and safety profile of statins.

RESULTS

One year after starting the statin therapy, patients treated with rosuvastatin had significantly greater decreases in total cholesterol and LDL cholesterol than subjects on atorvastatin or pravastatin. All statins led to a similar, significant reduction in serum levels of hsCRP and TNF-α, without correlation between biomarkers and lipid values, and toxicity rates were similar for all 3 statins.

CONCLUSION

Our findings suggest that rosuvastatin has a significantly greater lipid-lowering effect than atorvastatin or pravastatin, but all 3 statins exert a similar effect in lowering markers of inflammation as hsCRP and TNF-α.

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.

Treatment of dyslipidemia in HIV-infected patients

IMPORTANCE OF THE FIELD

Patients infected with HIV are at high risk for dyslipidemia, insulin resistance and cardiovascular disease. Therapies to reverse these risks are complex, sometimes controversial, and not uniformly effective.

AREAS COVERED IN THIS REVIEW

Pathophysiology of the lipid abnormalities in HIV is discussed, including the causes of alterations in triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and insulin resistance. We discuss the therapy of dyslipidemia in HIV using a combination of available clinical evidence and expert opinion based on extensive clinical experience, with discussions of lifestyle intervention and diet, conventional pharmacotherapy with lipid-lowering medications including statins, fibrates, niacin and thiazolidinediones for dyslipidemia, and newer therapeutic approaches including omega fatty acids, acipimox, growth hormone and leptin.

WHAT THE READER WILL GAIN

A detailed understanding of the pathophysiology and rational or evidence-based approach to therapy of lipid abnormalities in patients infected with HIV.

TAKE HOME MESSAGE

Treatment of dyslipidemia in patients with HIV is challenging and complicated by the risk of drug interactions. Appropriate therapy requires a sound understanding of pathophysiology and the principles of pharmacological and nonpharmacological therapeutic interventions. An evidence-based approach that combines lifestyle changes and drugs that are both safe and effective, singly and in combination, is described.

A pilot randomized trial comparing an intensive versus a standard intervention in stable HIV-infected patients with moderate-high cardiovascular risk

OBJECTIVES

The influence on the progression of atherosclerosis of an intervention on cardiovascular risk factors in HIV-infected patients remains unknown. We evaluated the efficacy and safety of an intensive versus a standard intervention in HIV-infected patients with moderate-high cardiovascular risk.

METHODS

A pilot randomized clinical trial. Stable HIV-infected patients with viral suppression on antiretroviral therapy, and two or more cardiovascular risk factors or a Framingham risk score >or=10%. An intensive intervention targeting low-density lipoprotein (LDL)-cholesterol <100 mg/dl, using antiplatelet therapy, and switching protease inhibitor (PI) therapy, was compared with the standard intervention aiming for LDL-cholesterol <130 mg/dL. The primary endpoint was progression of atherosclerosis measured by the carotid intima-media thickness (cIMT). Secondary endpoints were efficacy in achieving the LDL-cholesterol goal, changes in inflammatory biomarkers, and feasibility and safety of the intervention.

RESULTS

Thirty-two (47%) and 36 (53%) patients were assigned to the intensive and the standard interventions, respectively. After 12 months, the median proportion of change in the cIMT was +1.63% (-4.95 to +10.54) in the intensive intervention, and +1.79% (-6.61 to +6.1) in the standard group (P = 0.59). LDL-cholesterol (39% versus 7%, P < 0.001) and Framingham score (10% versus 0%, P = 0.03) showed larger reductions in the intensive group. No significant changes in levels of C-reactive protein, interleukin-6 and tumour necrosis factor-alpha were found. No significant adverse events were reported and no virological failures occurred during the study.

CONCLUSIONS

An aggressive intervention targeting LDL-cholesterol in HIV-infected patients was safe and capable of attaining very stringent target levels in adherent patients. However, the intervention did not influence cIMT progression or inflammatory biomarkers after 1 year of follow-up.

Drug/Drug interaction between lopinavir/ritonavir and rosuvastatin in healthy volunteers

OBJECTIVES

This open-label, single-arm, pharmacokinetic (PK) study in HIV-seronegative volunteers evaluated the bioequivalence of rosuvastatin and lopinavir/ritonavir when administered alone and in combination. Tolerability and lipid changes were also assessed.

METHODS

Subjects took 20 mg of rosuvastatin alone for 7 days, then lopinavir/ritonavir alone for 10 days, and then the combination for 7 days. Intensive PK sampling was performed on days 7, 17, and 24.

RESULTS

Twenty subjects enrolled, and PK data were available for 15 subjects. Geometric mean (+/-SD) rosuvastatin area under the concentration time curve (AUC)[0,tau] and maximum concentration (Cmax) were 47.6 ng.h/mL (+/-15.3) and 4.34 ng/mL (+/-1.8), respectively, when given alone versus 98.8 ng.h/mL (+/-65.5) and 20.2 ng/mL (+/-16.9) when combined with lopinavir/ritonavir (P < 0.0001). The geometric mean ratio was 2.1 (90% confidence interval [CI]: 1.7 to 2.6) for rosuvastatin AUC[0,tau] and 4.7 (90% CI: 3.4 to 6.4) for rosuvastatin Cmax with lopinavir/ritonavir versus rosuvastatin alone (P < 0.0001). There was 1 asymptomatic creatine phosphokinase elevation 17 times the upper limit of normal (ULN) and 1 liver function test elevation between 1.1 and 2.5 times the ULN with the combination.

CONCLUSIONS

Rosuvastatin low-density lipoprotein reduction was attenuated with lopinavir/ritonavir. Rosuvastatin AUC and Cmax were unexpectedly increased 2.1- and 4.7-fold in combination with lopinavir/ritonavir. Rosuvastatin and lopinavir/ritonavir should be used with caution until the safety, efficacy, and appropriate dosing of this combination have been demonstrated in larger populations.

Use of metabolic drugs and fish oil in HIV-positive patients with metabolic complications and associations with dyslipidaemia and treatment targets

BACKGROUND

Highly active antiretroviral therapy (HAART) with protease inhibitors (PI) is successful in suppressing viral replication, but may lead to a range of metabolic abnormalities associated with cardiovascular disease (CVD).

OBJECTIVES

The first objective of the study was to compare baseline demographic and clinical characteristics between PI users and non-PI users referred to a specialized metabolic clinic during 1999-2003. The second objective was to assess the associations of prescription drugs and fish oil with dyslipidaemia and to determine whether or not patients achieved treatment targets during 6 months of treatment.

METHODS

A retrospective analysis was performed using two sets of charts based on standardized forms with entries for personal data, drug treatment and clinical history. Anonymous linkage with the British Columbia HIV/AIDS Drug Treatment Program and the hospital laboratory was performed to gather information about HAART prescriptions and blood work.

RESULTS

In total, 237 patients were included in the study. There were few differences in any demographic or clinical factors between PI users and non-PI users. Compared with controls not taking lipid-lowering drugs or fish oil (n=48), statins appeared to be the only agent that was significantly associated with a reduced total cholesterol concentration (-15.6%; P=0.009). Fibrate treatment was associated with the largest reduction of triglyceride concentration (-37.4%; P=0.012), closely followed by fish oil (n=18;-32%; P=0.027). Six-month treatment success rates ranged between 17 and 43% of patients for total cholesterol (<5.2 mmol/L) and between 15 and 44% of patients for triglycerides (<2.3 mmol/L).

CONCLUSIONS

Despite the apparent lowering of blood lipids with drug and fish oil treatments, a majority of patients in these treatment groups (56.5-83.3%) still had elevated concentrations after 6 months.

Alteraciones lipídicas y riesgo cardiovascular asociado a la terapia antirretroviral

Dyslipidemia is common in HIV-infected patients receiving antiretroviral therapy (ART) and it is often associated with the use of specific antiretroviral drugs. The phenotypic profile can include elevated triglycerides or cholesterol alone, or mixed patterns with varying changes in LDL and HDL lipoproteins, which imply different levels of cardiovascular risk. Growing evidence indicates that ART-associated hyperlipidemia accelerates the development of atherosclerosis and coronary heart disease in HIV-infected patients. In recent years, a number of retrospective database reviews and prospective cohort studies have reported a higher incidence of coronary events in patients receiving ART, which seems to be closely related with the presence of dyslipidemia and the duration of exposure to ART. Although the clinical benefit of treating ART-related dyslipidemia remains unproven, most experts recommend a policy of cardiovascular disease prevention and management similar to that used in non-HIV-infected individuals. In addition, the use of antiretrovirals associated with a more favorable lipid profile is considered. Clinical experience with lipid-lowering therapy in HIV-infected patients is still limited, but there is increasing data confirming its efficacy and safety in this setting. Drug interactions should be taken into account when statins are used in patients receiving protease inhibitors.

The use of the Framingham equation to predict myocardial infarctions in HIV-infected patients: comparison with observed events in the D:A:D Study

BACKGROUND

The D:A:D (Data Collection on Adverse Events of Anti-HIV Drugs) Study, a prospective observational study on a cohort of 23 468 patients with HIV infection, indicated that the incidence of myocardial infarction (MI) increased by 26% per year of exposure to combination antiretroviral treatment (CART). However, it remains unclear whether the observed increase in the rate of MI in this population can be attributed to changes in conventional cardiovascular risk factors.

OBJECTIVE

To compare the number of MIs observed among participants in the D:A:D Study with the number predicted by assuming that conventional cardiovascular risk equations apply to patients with HIV infection.

METHODS

The Framingham equation, a conventional cardiovascular risk algorithm, was applied to individual patient data in the D:A:D Study to predict rates of MI by duration of CART. A series of sensitivity analyses were performed to assess the effect of model and data assumptions. Predictions were extrapolated to provide 10-year risk estimates, and various scenarios were modelled to assess the expected effect of different interventions.

RESULTS

In patients receiving CART, the observed numbers of MIs during D:A:D follow up were similar to or somewhat higher than predicted numbers: 9 observed vs 5.5 events predicted, 14 vs 9.8, 22 vs 14.9, 31 vs 23.2 and 47 vs 37.0 for<1 year, 1-2 years, 2-3 years, 3-4 years and >4 years CART exposure, respectively. In patients who had not received CART, the observed number of MIs was fewer than predicted (3 observed vs 7.6 predicted). Nine per cent of the study population have a predicted 10-year risk of MI above 10%, a level usually associated with initiation of intervention on risk factors.

CONCLUSIONS

A consistent feature of all analyses was that observed and predicted rates of MI increased in a parallel fashion with increased CART duration, suggesting that the observed increase in risk of MI may at least in part be explained by CART-induced changes in conventional risk factors. These findings provide guidance in terms of choosing lifestyle or therapeutic interventions to decrease those risk factors in much the same way as in persons without HIV infection.

Effect of pravastatin on body composition and markers of cardiovascular disease in HIV-infected men--a randomized, placebo-controlled study

OBJECTIVES

To determine the effect of the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, pravastatin, on markers of cardiovascular risk and lipodystrophy in HIV-infected, protease inhibitor (PI)-treated men with hypercholesterolaemia.

METHODS

A randomized, placebo-controlled, 16-week study was carried out on 33 HIV-infected, hypercholesterolaemic men (fasting total cholesterol > 6.5 mmol/L) on PI-containing therapy. Patients commenced dietary assessment and advice at week 0 and were randomized to 12 weeks pravastatin (40 mg each night) or placebo from week 4. The primary endpoint was the time-weighted change (TWAUC) in total cholesterol from week 0. Secondary endpoints included TWAUC cholesterol from week 4 (start of pravastatin), total and regional body fat, fasting lipids, glucose, insulin, and markers of cardiovascular risk.

RESULTS

Of 33 men randomized (pravastatin n = 16, mean age 48 years), 31 completed the study. Groups were matched for baseline cholesterol and body composition. Although there was no significant between-group difference in TWAUC cholesterol from week 0 (pravastatin -0.6 +/- 1.0 versus placebo -0.4 +/- 1.0 mmol/L/week; P = 0.8), TWAUC cholesterol from week 4 decreased more in the pravastatin group (-0.8 +/- 1.0 versus -0.3 +/- 0.9 mmol/L/week; P = 0.04). Neither triglycerides nor dietary intake changed. Subcutaneous fat increased significantly with pravastatin (+0.72 +/- 1.55 versus +0.19 +/- 0.48 kg change in limb fat, P < 0.04; +5.2 +/- 8.7 versus -1.3 +/- 13.7 cm change in abdominal subcutaneous fat, P = 0.02). Apart from homocystine, which decreased in the pravastatin group, there were no significant differences in other cardiovascular, lipid or glucose parameters.

CONCLUSIONS

Despite limited effects on cholesterol, 12 weeks use of pravastatin 40 mg each night in HIV-infected men with hypercholesterolaemia resulted in significant increases in subcutaneous fat.

Treatment of dyslipidaemia in HIV-infected persons

Accumulating evidence suggests that HIV-infected individuals have an increased risk of cardiovascular events. This risk seems to be at least partially mediated by dyslipidaemia, which is related to the use of highly active antiretroviral therapy (HAART). As HIV-infected individuals live longer due to HAART, their cardiovascular risk will invariably increase. Because HAART is likely to be used indefinitely, HAART-related dyslipidaemia has emerged as a major cardiovascular concern. This article summarises the evaluation of dyslipidaemia and cardiovascular risk in HIV-infected individuals, the potential pathophysiological and genetic mechanisms involved in HAART-related dyslipidaemia and the current treatment approaches. In general, dyslipidaemia is evaluated and treated as in HIV-negative persons. The first step is cardiovascular risk assessment and the determination of target lipid levels. A healthier lifestyle and, in particular, smoking cessation should be promoted. Lowering levels of low-density lipoprotein cholesterol (or, in the setting of significant hypertriglyceridaemia, non-high-density lipoprotein cholesterol) is the primary target of intervention. Switching HAART to a more lipid-favourable regimen should be considered if this does not jeopardise virological control. Many patients will need lipid-lowering drug therapy. Appropriate low-density lipoprotein cholesterol target levels may be more difficult to reach than in the HIV-negative population, and the potential for drug interactions when using lipid-lowering agents together with HAART needs to be considered. The identification of HAART strategies with no or minimal metabolic toxicity, and the identification of the safest and most efficacious lipid-lowering therapies for HIV-infected individuals with dyslipidaemia are important research goals.

Inhibition of human organic anion transporting polypeptide OATP 1B1 as a mechanism of drug-induced hyperbilirubinemia

OATP1B1 (a.k.a. OATP-C, OATP2, LST-1, or SLC21A6) is a liver-specific organic anion uptake transporter and has been shown to be a higher affinity bilirubin uptake transporter than OATP1B3. Using human embryonic kidney (HEK 293) cells stably transfected with OATP1B1, we have studied the effects of indinavir, saquinavir, cyclosporin A, and rifamycin SV on human OATP1B1 transport function. These drugs are potent inhibitors of OATP1B1 transport activity in vitro. We further provide evidence that the calculated fraction of OATP1B1 inhibited at the clinical exposure level correlated very well with the observed hyperbilirubinemia outcome for these drugs in humans. Our data support the hypothesis that inhibition of OATP1B1 is an important mechanism for drug-induced unconjugated hyperbilirubinemia. Inhibition of OATPs may be an important mechanism in drug-drug and drug-endogenous substance interactions.

Management of Dyslipidaemia in HIV-Infected Patients Receiving Antiretroviral Therapy

Dyslipidaemia associated with the treatment of HIV infection, particularly with the use of protease inhibitors (PIs), can raise cholesterol and triglyceride (TG) levels to the thresholds indicated for intervention. Recent evidence from epidemiological studies has shown that there are correlations between antiretroviral drug use and increased risks for, and incidences of, cardiovascular disease, including myocardial infarction and coronary heart disease. The primary goals of dyslipidaemia therapy for HIV patients are reductions of both low-density lipoprotein cholesterol (LDL-C) and markedly elevated TG levels. Dietary strategies and exercise programs may be tried, although these have shown inconsistent results. The two options for drug therapy are switching anti-retroviral agents and using lipid-lowering drugs. Each approach is associated with advantages and limitations, and the need to maintain viral suppression must be balanced with the need to treat abnormal lipid levels. Most drug switches replace the PI component with drugs from another antiretroviral class. Selection of drug therapy for lipid lowering depends on the type of dyslipidaemia predominating and the potential for drug interactions. The use of the statins pravastatin and atorvastatin is recommended for the treatment of patients with elevated LDL-C levels and gemfibrozil or fenofibrate for patients with elevated TG concentrations. Development of new PIs with more favourable effects on the lipid profile should be of benefit.

HIV-related lipodystrophy and related factors

As new therapies for HIV infection have been developed, some of the clinical focus related to AIDS and HIV infection has shifted from acute care, to more chronic issues. Some of these new clinical issues seem related to the HIV infection itself, while others seem to be side effects of therapeutic efforts. Metabolic abnormalities, such as dyslipidemia, insulin resistance, and lipodystrophy (LD) have been observed. The clinical importance of these is demonstrated by the increased prevalence of cardiovascular disease and diabetes in HIV infected persons. LD is a general term used to describe varying degrees of fat redistribution, including lipoatrophy and lipohypertrophy, in different body regions. Though LD was observed in persons with HIV infection before highly active treatment regimens were developed, the prevalence of LD has seemingly increased drastically with the widespread use of more active therapies. It has been postulated that protease inhibitors (PI), especially, are linked to the development of LD. This review will assess the epidemiologic information related to HIV-associated LD, and related metabolic syndromes. In addition, potential mechanisms accounting for these syndromes will be reviewed. In general, the available data do not define a single, definable etiology or mechanism explaining these clinical conditions, but suggest that these conditions are caused by a complex interaction potentially involving such things as the side effects of medications, alteration of immune function, and individual subject characteristics, such as body weight and baseline lipid level.

Effects of pravastatin on lipoproteins and endothelial function in patients receiving human immunodeficiency virus protease inhibitors

BACKGROUND

Although recommended as initial therapy for patients with dyslipidemia who are taking human immunodeficiency virus protease inhibitors (HIV PIs), the effects of pravastatin on lipoproteins and arterial reactivity have not been elucidated. The purpose of this study was to determine the effects of pravastatin on lipoprotein subfractions and endothelial function in patients with dyslipidemia who are receiving HIV PIs.

METHODS

This was a placebo-controlled, double-blind, crossover study comparing pravastatin (40 mg) to placebo in 20 patients who were taking HIV PIs. Lipoprotein subfractions were measured with nuclear magnetic resonance spectroscopic analysis. Flow-mediated vasodilation (FMD) of the brachial artery was evaluated with high-resolution ultrasound scanning.

RESULTS

At baseline, subjects had an increased concentration of low-density lipoprotein (LDL) particles (1756 +/- 180 nmol/L), which tended to be small (19.9 +/- 0.2 nm), a low concentration of large high-density lipoproteins (HDL; 0.94 +/- 0.07 mmol/L), and an increased concentration of large very low-density lipoproteins (VLDL; 1.90 +/- 0.58 mmol/L). FMD was impaired (4.5% +/- 1.1%). Compared with placebo, pravastatin resulted in a 20.8% reduction in LDL particles (P =.030), a 26.7% reduction in small LDL (P =.100), and a 44.9% reduction in small VLDL (P =.023). Total and non-HDL cholesterol levels decreased by 18.3% (P <.001) and 21.7% (P <.001), respectively. FMD tended to increase in patients receiving pravastatin (0.7% +/- 0.6%); however, the difference between treatment phases was not statistically significant (P =.080).

CONCLUSIONS

This is the first double-blind, placebo-controlled study of the effects of statin therapy on lipids, lipoprotein subfractions, and endothelial function in patients taking HIV PIs. Pravastatin reduced concentrations of atherogenic lipoproteins, particularly those most associated with future coronary events.

HIV Lipodystrophy Syndrome: A Primer

Treatment with highly active antiretroviral therapy (HAART) has been implicated in the development of anthropomorphic and metabolic abnormalities termed HIV lipodystrophy syndrome (or LDS). This primer offers a comprehensive overview of LDS including epidemiology, hypothesized etiologies, and clinical consequences. The evidence-based literature is reviewed for current treatment strategies including discontinuation of specific antiretrovirals, pharmacological management of dyslipidemia and insulin resistance, exercise training, facial augmentation, liposuction, and hormonal therapy. Patient education, counseling, and adherence are discussed.

Management of dyslipidemias in the age of statins

Evidence for the effectiveness of lipid-lowering therapy in reducing CHD risk continues to emerge. In primary prevention, clinical trials have demonstrated a benefit for middle-aged, high-risk men with high LDL cholesterol and, more recently, for men and women with "average" LDL and low HDL cholesterol. Although low HDL cholesterol, small dense LDL particles, elevated lipoprotein (a), elevated apolipoprotein B, and the dyslipidemia of the metabolic syndrome pose an increased in CHD risk in some patients, the risk reduction with lipid-lowering therapy has not been fully investigated. The CHD risk of isolated hypertriglyceridemia remains uncertain. Very high triglyceride levels, however, should be treated to prevent pancreatitis. A lipid-lowering diet and other appropriate lifestyle changes constitute safe advice for all patients with dyslipidemia. In initiating pharmacologic therapy, physicians should view potential risk reduction in the context of a patient's overall CHD risk. The selection of particular medications can be individualized, considering effectiveness evidence from clinical trials, lipid-lowering potency, adverse effects, drug interactions, costs, and patient preferences.

Hyperlipidaemia in patients with HIV-1 infection receiving highly active antiretroviral therapy: epidemiology, pathogenesis, clinical course and management

A wide range of abnormalities of lipid metabolism have been recently described in HIV-infected patients receiving a protease inhibitor (PI)-based highly active antiretroviral therapy, including hypertriglyceridaemia and hypercholesterolaemia. The increase of plasma lipid concentrations may involve up to 70-80% of HIV-positive subjects treated with a PI-containing regimen and are frequently (but not always) associated with the fat redistribution or the lipodystrophy syndrome. Multiple pathogenetic mechanisms by which antiretroviral agents lead to dyslipidaemia have been hypothesized, but they are still controversial. The potential clinicopathological consequences of HIV-associated hyperlipidaemia are not completely known, but several anecdotal observations report an increased risk of premature coronary artery diseases in young HIV-positive individuals receiving PIs, besides peripheral atherosclerosis and acute pancreatitis. A limited-to-significant improvement of increased triglyceride and cholesterol plasma levels was described in patients who replaced PIs with nevirapine, efavirenz or abacavir, but the risks of long-term toxicity and virological relapse of this treatment switching are not completely defined. A hypolipidaemic diet and regular physical exercise may act favorably on dyslipidaemia, but pharmacological therapy becomes necessary when hyperlipidaemia is severe or persists for a long time. The choice of hypolipidaemic drugs is problematic because of potential pharmacological interactions with antiretroviral compounds and other antimicrobial agents, associated with an increased risk of toxicity and intolerance. Statins are considered the first-line therapy for the PI-related hypercholesterolaemia, while fibrates are the cornerstone of drug therapy when predominant hypertriglyceridaemia is of concern.

Incidence of hyperlipidaemia in a cohort of 212 HIV-infected patients receiving a protease inhibitor-based antiretroviral therapy

Two hundred and twelve HIV-positive patients who started a new protease inhibitor (PI)-based antiretroviral regimen between January 1998 and December 2000 in our tertiary care centre were prospectively followed-up during a 12-month study period, in order to assess the incidence of hyperlipidaemia and related clinical adverse events. At the end of 1-year follow-up, PI-containing antiretroviral treatment led to a statistically significant increase in serum triglyceride levels (P<0.005) and total and LDL-cholesterol levels (P<0.05). The overall incidence of hypertriglyceridaemia and hypercholesterolaemia was 38.2 and 25%, respectively. The incidence of increased serum triglyceride levels was significantly higher in patients treated with ritonavir (66.6%) or lopinavir/ritonavir (60.7%), compared with other PIs (P<0.04). Clinical adverse events possibly related to the hyperlipidaemia (such as cardiovascular diseases or acute pancreatitis) were not observed during the entire 12 months study period. In conformity with other previously published studies, the very high incidence of hyperlipidaemia during a PI-based therapy recognised in our work raises a big concern about its potential clinico-pathological consequences and the most convenient pharmacological management of these metabolic imbalances.

Statins and fibrates for the treatment of hyperlipidaemia in HIV-infected patients receiving HAART

OBJECTIVES

The aim of our work is to evaluate the role of statins and fibrates in the management of hyperlipidaemia in HIV-infected patients receiving highly active antiretroviral therapy.

DESIGN

Open-label, randomized, prospective study of the efficacy and safety of bezafibrate, gemfibrozil, fenofibrate, pravastatin and fluvastatin as pharmacologic treatment for protease inhibitor-related dyslipidaemia.

METHODS

Plasma lipid levels of 656 HIV-infected patients who referred to our tertiary care centre and were on protease inhibitor-based antiretroviral therapy for at least 12 months have been evaluated. All patients had HIV viral load < 50 copies/ml and presented with hypertriglyceridaemia of at least 6 months duration that was unresponsive to a hypolipidaemic diet; all have been treated with bezafibrate, gemfibrozil, fenofibrate, pravastatin, or fluvastatin for 12 months.

RESULTS

Of the 656 patients observed 113 (17.2%) received pharmacological therapy, while seven patients were excluded from evaluation due to early drop-out. Of the 106 evaluable subjects, bezafibrate was used in 25 cases, gemfibrozil in 22, fenofibrate in 22, pravastatin in 19, and fluvastatin in 18. At the close of 1-year follow-up, fibrates led to a reduction of 40.7% and 21.9% versus baseline triglyceridaemia and cholesterolaemia, respectively (P < 0.001), and statins led to a reduction of 34.8% and 25.2% versus baseline triglyceride and total cholesterol levels, respectively (P < 0.001), without significant differences according to each different administered hypolipidaemic drug.

CONCLUSIONS

All administered statins and fibrates revealed a similar, significant efficacy in the treatment of diet-resistant hyperlipidaemia, and showed a favourable tolerability profile.

Evaluation and management of metabolic and coagulative disorders in HIV-infected patients receiving highly active antiretroviral therapy

A number of metabolic disorders, including hypercholesterolemia, hypertriglyceridemia, insulin resistance, elevated fasting glucose and diabetes mellitus, were reported in a high proportion of HIV-infected patients receiving highly active antiretroviral therapy (HAART). Less frequently, coagulative disorders were described in patients receiving HAART. Since all these metabolic disorders may predispose to coronary heart disease, an early evaluation and treatment is advisable. Existing guidelines for uninfected patients may be applied, taking into account, however, the potential for drug interactions and accumulated toxicity. It may be helpful to stratify all patients in three risk groups to plan regular diagnostic screening. Treatment of dyslipidemia and diabetes mellitus should include a first-line approach with non-pharmacological interventions. Statins and fibrates are proposed for HIV-infected patients with HAART-related hyperlipidemia, but concern has been raised on their potential for interaction with antiretrovirals and hepatic and muscle toxicity. Metformin and thiazolidenediones (or glitazones), hypoglycemic agents that increase insulin sensitivity, are presently under evaluation in diabetic and glucose-intolerant HIV-infected patients treated with HAART. Glitazones also have a potential for ameliorating the lipodystrophic syndrome. The routine evaluation of coagulative parameters is probably not advisable until a benefit of widespread screening is assessed in prospective studies. A heightened awareness of the possiblity of coagulative disorders, together with controlled trials and basic research, is needed.

Lipodystrophy, insulin resistance, diabetes mellitus, dyslipidemia, and cardiovascular disease in human immunodeficiency virus infection

The introduction of highly active antiretroviral therapy has significantly reduced morbidity and mortality in patients infected with the human immunodeficiency virus. Treatment with antiretroviral agents--protease inhibitors in particular--has uncovered a syndrome of abnormal fat redistribution, dyslipidemia, and impaired glucose metabolism, collectively termed lipodystrophy syndrome. The cause of the syndrome seems to be multifactorial; however, its exact mechanisms have yet to be elucidated. Accelerated risk for cardiovascular disease is likely to be a major concern in these patients in the future. At this time, no clinical guidelines are available for the prevention and/or the treatment of lipodystrophy syndrome. The available treatment options range from switching the different antiretroviral drugs and lifestyle modifications to the use of pharmacologic agents to treat patients with dyslipidemia, impaired glucose tolerance and/or diabetes, and changes in body composition. This review emphasizes the clinical features, potential molecular mechanisms, and treatment options for patients infected with human immunodeficiency virus who have lipodystrophy syndrome.

Evaluation and management of dyslipidemia in patients with HIV infection

OBJECTIVE

Persons with HIV infection develop metabolic abnormalities related to their antiretroviral therapy and HIV infection itself. The objective of this study was to summarize the emerging evidence for the incidence, etiology, health risks, and treatment of dyslipidemias in HIV disease.

DESIGN

Systematic review of original research with quantitative synthesis.

MAIN RESULTS

Dyslipidemia is common in persons with HIV infection on highly active antiretroviral therapy (HAART), but methodologic differences between studies preclude precise estimates of prevalence and incidence. The typical pattern includes elevated total cholesterol, low-density lipoprotein cholesterol, and triglycerides, which may be markedly elevated. The dyslipidemia may be associated with lipodystrophy, insulin resistance, and, rarely, frank diabetes mellitus. Exposure to protease inhibitors (PIs) is associated with this entire range of metabolic abnormalities. PI-naïve patients on nucleoside reverse transcriptase inhibitors (NRTIs) may develop lipodystrophy, insulin resistance, hypercholesterolemia, and possibly modest elevations in triglycerides but not severe hypertriglyceridemia, which appears to be linked to PIs alone. Most studies have not found an association between CD4 lymphocyte count or HIV viral load and lipid abnormalities. The pathogenesis is incompletely understood and appears to be multifactorial. There are insufficient data to definitively support an increased coronary heart disease risk in patients with HIV-related dyslipidemia. However, some of the same metabolic abnormalities remain firmly established risk factors in other populations. Patients on HAART with severe hypertriglyceridemia may develop pancreatitis or other manifestations of the chylomicronemia syndrome. Some of the metabolic derangements (particularly hypertriglyceridemia) may improve upon replacing a PI with a non-nucleoside reverse transcriptase inhibitor. The limited experience suggests that fibrates, pravastatin, and atorvastatin can safely treat lipid abnormalities in HIV-infected patients.

CONCLUSIONS

Patients with HIV infection on HAART should be screened for lipid disorders, given their incidence, potential for morbidity, and possible long-term cardiovascular risk. Treatment decisions are complex and must include assessments of cardiac risk, HIV infection status, reversibility of the dyslipidemia, and the effectiveness and toxicities of lipid-lowering medications. The multiple potential drug interactions with antiretroviral or other HIV-related medications should be considered in lipid-lowering drug selection and monitoring.

Selected metabolic and morphologic complications associated with highly active antiretroviral therapy

Metabolic and morphologic changes have been described in patients with human immunodeficiency virus (HIV) infection. In the short term, these disorders can be debilitating and may require medical intervention, including alterations in antiretroviral therapy regimens. The long-term consequences have not been fully realized, but are important, particularly in the era of durable HIV disease management with highly active antiretroviral therapy. This review focuses on 3 of the important morphologic or metabolic changes, namely alterations in body fat distribution, dyslipidemia, and lactic acidosis. The prevalence of each of these disorders remains unknown due to varied definitions and difficulty in recognition of the conditions for both the patient and the clinician. Treatment regimens directed at these abnormalities are being developed, but clinical trials are needed to fully ascertain the efficacy and safety of such interventions.

Risk-benefit of HMG-CoA reductase inhibitors in the treatment of HIV protease inhibitor-related hyperlipidaemia

HIV protease inhibitors decrease mortality and improve quality of life in patients with HIV infection. However, these drugs have been associated with serum lipid elevations, which may pose an increased risk of cardiovascular disease and pancreatitis. Treatment of protease inhibitor-related hyperlipidaemia (PIH) is complicated by drug interactions, which significantly increase concentrations of most 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins). Although pravastatin and atorvastatin effectively lower cholesterol and triglyceride concentrations in HIV-infected patients, a significant number of patients did not achieve their National Cholesterol Education Program low density lipoprotein concentration goals. Nonetheless, due to the increased risk of rhabdomyolysis with elevated statin concentrations, atorvastatin should be considered a second-line agent. The limited available PIH data supports the fact that pravastatin and atorvastatin are well-tolerated in HIV-infected individuals. More data are needed on the appropriate starting doses, maximum safe doses, role of combination statin-fibrate therapy, documentation of coronary heart disease benefit and incidence of myotoxicity and hepatotoxicity. Pravastatin has an acceptable risk-benefit ratio in PIH, while theoretical toxicity concerns exist with atorvastatin.

COX-2 selective inhibitors: analysis of the renal effects

COX-2 selective inhibitors provide analgesia and blunt inflammation while also sparing the gastrointestinal tract from classic NSAID toxicity. Therapeutic effects are thought to result from inhibition of the inflammatory COX-2 isoform. Organ sparing is considered the result of preservation of homeostatic COX-1 enzyme function. Similar roles of the COX isoforms in the kidney would reduce NSAID-associated nephrotoxicity. However, human kidney tissue expresses COX-2 enzyme, suggesting a role for this isoform in maintenance of physiological renal processes. Available clinical data on the renal effects of COX-2 selective inhibitors in humans also demonstrate nephrotoxic potential.

HIV-associated lipodystrophy: description, pathogenesis, and molecular pathways

HIV-infected individuals taking antiretroviral medications may experience changes in body shape and metabolism, commonly known as HIV-associated lipodystrophy (HIVLD). In vitro and in vivo research have revealed numerous effects of both protease inhibitors and nucleoside reverse transcriptase inhibitors on the function of various organs--most importantly adipose tissue, liver, and muscle. The metabolic abnormalities could result in an increased risk of cardiovascular disease in this vulnerable and relatively young population. Treatment strategies, normally successful in the general population, have generally been less effective in this group of people, in which the detrimental effects of the antiretroviral medications are ongoing.

Drugs and cardiotoxicity in HIV and AIDS

The advent of potent antiretroviral drugs in recent years has had an impressive impact on mortality and disease progression in HIV-infected patients, so that issues related to long-term effects of drugs are of growing importance. Hyperlipidemia, hyperglycemia, and lipodystrophy are increasingly described adverse effects of highly active antiretroviral therapy (HAART), in particular when protease inhibitors are used. Hyperlipidemia is strikingly associated with the use of most available protease inhibitors, with an estimated prevalence of up to 50%. Because of the short observation period and the small number of cardiovascular events, epidemiological evidence for an increased risk of coronary heart disease in HIV-infected patients treated with HAART is not adequate at present; however, it is likely that shortly more data will accumulate to quantify this risk. Before starting HAART and during treatment it is reasonable to evaluate all patients for traditional coronary risk factors, including lipid profile. Among the drugs that are currently used in HIV+ patients, antibacterials, antifungals, psychotropic drugs and anti-histamines have been associated with QT prolongation or torsade de pointe, a life-threatening ventricular arrhythmia. Among the risk factors that may precipitate an asymptomatic electrocardiographic abnormality into a dangerous arrhythmia is the concomitant use of drugs that share the CYP3A metabolic pathway. Since most protease inhibitors are potent inhibitors of CYP3A, clinicians should be aware of this potentially dangerous effect of HAART. Anthracyclines are potent cytotoxic antibiotics that have been widely used for the treatment of HIV-related neoplasms. Their cardiotoxicity is well known, ranging from benign and reversible arrhythmias to progressive severe cardiomyopathy. The increased survival and quality of life of HIV+ patients emphasize the importance of a high awareness of adverse drug-related cardiac effects.

Antiretroviral Therapy and the Lipodystrophy Syndrome

‘Lipodystrophy syndrome’ in the setting of HIV infection has come to encompass a collection of morphological and metabolic abnormalities linked with the use of antiretroviral therapy and other risk factors. We review the clinical literature on this subject as it has evolved historically, taking pertinent methodological issues into account.