Increase of atherogenic plasma profile in HIV-infected patients treated with protease inhibitor-containing regimens

HAART-associated dyslipidemia varies by biogeographical ancestry in the multicenter AIDS cohort study

Highly active antiretroviral therapy (HAART) has been successful in delaying the progression to AIDS in HIV-1-infected individuals. Exposure to HAART can result in metabolic side effects, such as dyslipidemia, in a subset of recipients. Longitudinal data and frozen peripheral blood mononuclear cell pellets were obtained from 1,945 men enrolled in the Multicenter AIDS Cohort. Individuals were genotyped for ancestry informative markers (AIMs) and stratified by biogeographical ancestry (BGA). Then serum levels of total cholesterol (TCHOL), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TRIG) were examined controlling for a number of HIV and HAART-related covariates using multivariate mixed-effects linear regression. HIV-1 infection, in the absence of HAART, was associated with altered lipid levels for all phenotypes tested when compared to HIV-negative men. HIV-1-infected men receiving HAART also had significantly different lipid levels compared to HIV-negative men, except for LDL-C. There were statistically significant interactions between BGA and HIV/HAART status for all lipids tested. BGA remained significantly associated with lipid levels after controlling for other HIV and HAART-related covariates. There was low concordance between self-reported race (SRR) and BGA in admixed populations. BGA performed better than SRR in our statistical models. Lipid profiles in untreated HIV-1-positive men and HIV-1-positive men receiving HAART differ from HIV-negative men and this effect varies by BGA. BGA performed better in our statistical analysis as a racial classifier but SRR remains a good clinical surrogate for BGA.

[Lipid profile of atazanavir]

It is currently known that exposure to antiretroviral treatment, particularly to the classic protease inhibitors, is associated with an increased risk of suffering from cardiovascular disease, although stopping antiretroviral treatment can cause an even greater risk. Recommendations have been made on how to deal with dyslipaemia and cardiovascular risk in seropositive patients. These recommendations are similar to those for the general population, but include the particular feature of considering including benign treatment with lipids wherever possible. Atazanavir has different characteristics from other protease inhibitors as regards its effects on adipose tissue and metabolism in general. Atazanavir is not associated with increases in total cholesterol, LDL-cholesterol or triglycerides as with other PI in initial, rescue or simplification therapy. The results of in vitro studies and clinical studies are clear and convincing. These characteristics give it a particular role that is very attractive when deciding the most suitable antiretroviral treatment for a proportion of HIV-infected patients in whom the reduction in cardiovascular risk is seen as a priority.

Longitudinal changes in serum lipids among HIV-infected men on highly active antiretroviral therapy

OBJECTIVE

The aim of the study was to describe longitudinal changes in serum lipids among HIV-infected men receiving highly active antiretroviral therapy (HAART) with long-term follow-up.

METHODS

A total of 304 HIV-infected men who initiated HAART and who had serum lipid measurements prior to and for up to 7 years after HAART initiation were identified from the Multicenter AIDS Cohort Study (MACS). Mean levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were examined at biannual time-points.

RESULTS

Significant lipid changes were seen within 0.5 years of HAART initiation but increases in TC (+1.09 mmol/L), LDL-C (+0.57 mmol/L), HDL-C (+0.16 mmol/L) and non-HDL-C (+0.91 mmol/L) reached peak levels 2-3 years after HAART initiation. Declines in serum TC, LDL-C and non-HDL-C in subsequent years occurred concurrently with a substantial increase in use of lipid-lowering medications (from 1% usage pre-HAART to 43% 6-7 years after HAART initiation) but the proportion of men who either were treated with cholesterol-lowering medication or had elevated cholesterol levels (>5.18 mmol/L) did not change during the 2-7-year interval after HAART. Mean HDL-C also decreased after 2-3 years and was low (<1.04 mmol/L) in 55% of HIV-infected men 6-7 years after HAART initiation.

CONCLUSIONS

Atherogenic serum lipids increased early after the initiation of HAART, peaked at 2-3 years and remained high or required treatment thereafter. Low HDL-C levels persisted in the majority of men. The long-term effects of lipid abnormalities on cardiovascular risk and the effectiveness and toxicity of prolonged use of lipid-lowering medications in combination with HAART are not known.

Antiretroviral therapy in HIV-positive men is associated with increased apolipoprotein CIII in triglyceride-rich lipoproteins

OBJECTIVES

Dyslipidaemia has become a common problem in HIV disease, especially in patients on current antiretroviral therapy. However, the pathogenic mechanisms involved are not well understood or documented using conventional lipid measurements.

METHODS

Using a cross-sectional design, the prevalence of abnormal standard lipid measurements and novel biomarkers for abnormal lipid metabolism was determined in 271 HIV-positive men from two HIV clinics in Atlanta, GA, USA.

RESULTS

A total of 147 men were treated with protease inhibitors (PIs) for >3 months (54%), 84 were treated with nonnucleoside reverse transcriptase inhibitors (NNRTIs) for >3 months (31%) and 40 had not received antiretroviral therapy in the past 3 months (15%). Patients being treated with a PI had higher total cholesterol and triglyceride (TG) levels than patients on no therapy (P<0.05 for each). Patients in the NNRTI group had higher TG, lower high-density lipoprotein (HDL) levels, and higher low-density lipoprotein (LDL) levels than patients on no therapy (P<0.05 for each). Patients treated with either PIs or NNRTIs were more likely to have higher apolipoprotein CIII (apoCIII) levels (P<0.05 for each) than patients on no therapy. Elevated TG was associated with disproportionably elevated apoCIII levels in both treatment groups.

CONCLUSIONS

In this cross-sectional study of HIV-infected men, either PI or NNRTI therapy elevated levels of TG and apoCIII. Higher concentrations of apoCIII in apoB-containing lipoproteins [very low-density lipoproteins (VLDLs), intermediate density lipoprotein (IDL) and LDLs] have been predictive of an increased incidence of coronary events in clinical trials and more rapid progression of coronary lesions measured by angiography. These findings, on a background of an older population with additional risk factors of smoking and diabetes, portend future atherosclerotic events in these patients.

The Protease Inhibitor Transfer Study (PROTRA 1): abacavir and efavirenz in combination as a substitute for a protease inhibitor in heavily pretreated HIV-1-infected patients with undetectable plasma viral load

OBJECTIVES

The aim of the study was to evaluate the safety and efficacy of abacavir (ABC) and efavirenz (EFV) instead of a protease inhibitor (PI) in HIV-1-infected subjects treated with two nucleoside reverse transcriptase inhibitors (NRTIs) and one PI with undetectable viral loads (< 50 HIV -1 RNA copies/mL). To be eligible for inclusion, patients had to have a history of viral load < 400 copies/mL for at least 3 months and had to be naive to treatment with nonnucleoside reverse transcriptase inhibitors (NNRTIs) and ABC, but multiple pretreatment and treatment failure were allowed.

DESIGN

An open-label, single-centre pilot study of duration 48 weeks was conducted. ABC was added to the original treatment with two NRTIs and one PI at baseline, and at week 6 the PI was replaced by EFV. At each study visit, CD4 cell count, viral load [measured by polymerase chain reaction (PCR)] and clinical chemistry were measured. Fasting blood samples were taken at baseline and at weeks 12, 24, 36 and 48 to measure levels of cholesterol [high-density lipoprotein (HDL)/low-density lipoprotein (LDL)], triglycerides, insulin and C-peptide. Additionally, an oral glucose tolerance test (OGTT) was performed. A bioelectric impedance analysis (BIA) and a single slice abdominal and mid-thigh computed tomography (CT) scan were carried out to assess changes in body composition.

RESULTS

Thirty patients were included in the study. Three patients experienced ABC-hypersensitivity and one patient demonstrated virological failure caused by nonadherence. At week 48, all remaining patients had viral loads < 50 copies/mL with stable CD4 counts. The fasting metabolic parameters and abdominal fat distribution remained unchanged.

CONCLUSIONS

In heavily pretreated patients, ABC and EFV in combination provide an effective, simplified and well-tolerated alternative to PI treatment.

Fibrates or statins and lipid plasma levels in 245 patients treated with highly active antiretroviral therapy. Aquitaine Cohort, France, 1999-2001

OBJECTIVES

To describe the effect and tolerance of lipid-lowering drugs (LLD; fibrates and statins) in patients treated with highly active antiretroviral therapy (HAART).

METHODS

A prospective study was performed in a large cohort of HAART-treated HIV-infected patients using guidelines for case management of dyslipidaemia. Inclusion criteria were: age over 18 years; HIV infection treated with HAART including at least one protease inhibitor (PI) or nonnucleoside reverse transcriptase inhibitor (NNRTI); total cholesterol (TC)>5.5 mmol/L and/or triglycerides (TG)>2.2 mmol/L; and initiation of fibrates or statins. Viral load, CD4 cell count, plasma lipid levels and liver enzymes were measured at baseline (M0) and 3(M3) and 12(M12) months thereafter. Muscular enzymes were not assessed.

RESULTS

Fibrates were prescribed to 179 patients and statins to 66 patients. There was a significant mean decrease of TG in the fibrates group between M0 and M3 [-2.29 mmol/L; 95% confidence interval (CI)=-3.53, -1.05; P<10(-4)] and between M0 and M12 (-2.25 mmol/L; 95% CI:-4.23, -0.29; P<10(-4)); a significant decrease of TC was also noticed between M0 and M3 (-0.55 mmol/L; 95% CI:-0.95, -0.15; P=0.008) but not at M12 (-0.33 mmol/L; 95% CI:-0.94, 0.26; P=0.27). In the statins group, TC significantly decreased between M0 and M3 (-0.78 mmol/L; 95% CI:-1.3, -0.27; P=0.004) and between M0 and M12 (-0.70 mmol/L; 95% CI:-1.31, -0.09; P=0.03). There was no significant difference between the decreases of TG or TC observed in patients treated with PI or NNRTI. There were no significant modifications of viral load, CD4 cell count or liver enzymes during the 12 months of followup.

CONCLUSIONS

In this HAART-treated cohort, fibrates and statins were safe and associated with a favourable but moderate effect on lipid plasma levels.

Risk factors for coronary heart disease in patients treated for human immunodeficiency virus infection compared with the general population

The distribution of risk factors for cardiovascular disease in patients aged 35-44 years who were treated for human immunodeficiency virus type 1 (HIV-1) infection was compared with that for a population-based cohort. HIV-1-infected men treated with a protease inhibitor-containing regimen (n=223), compared with HIV-1-uninfected men (n=527), were characterized by a lower prevalence of hypertension, a lower mean high-density lipoprotein cholesterol level, a higher prevalence of smoking, a higher mean waist-to-hip ratio, and a higher mean triglyceride level. No difference was found for total plasma or low-density cholesterol levels, nor for the prevalence of diabetes. Similar trends were observed among female subjects. The predicted risk of coronary heart disease was greater among HIV-1-infected men (relative risk [RR], 1.20) and women (RR, 1.59; P<10(-6) for both), compared with the HIV-1-uninfected cohort. The estimated attributable risks due to smoking were 65% and 29% for HIV-1-infected men and women, respectively. Because most HIV-1-infected people will ultimately need antiretroviral therapy, risk factors for cardiovascular disease should be determined at the initiation of treatment, and interventions should be considered for all patients who have them.

Restoration of human immunodeficiency virus-1-specific responses in patients changing from protease to non-nucleoside reverse transcriptase inhibitor-based antiretroviral therapy

The effect of altering antiretroviral therapy (ART) on responses to viral, recall and human immunodeficiency virus (HIV)-1-specific recombinant antigens and interleukin-2 (IL-2) in HIV-1-infected patients was assessed. A longitudinal cohort study in eight HIV-1 infected individuals following a clinically indicated therapy change (seven for drug intolerance and one for virological failure) from protease inhibitor (PI) to non-nucleoside reverse transcriptase inhibitor (NNRTI)-based antiretroviral regimens was performed. CD4 T-cell counts, viral loads, lymphoproliferative responses, cytokine production and latent proviral deoxyribonucleic acid (DNA) were measured at baseline and at weeks 12 and 24 after therapy substitution. Following therapy-switch there was a 33% proportional increase in mitogen response (95% confidence interval (CI), 3-33%) and a 31% increase (95% CI, 15-48%) in viral and recall-antigen responses. Six patients developed proliferative responses to low concentration IL-2 stimulation. All patients demonstrated an increase in median HIV-1-specific responses, as three had detectable virus at baseline (two being viral rebound); this may reflect an autovaccination effect. Proviral DNA changes largely reflected plasma HIV-1 ribonucleic acid (RNA). In conclusion, NNRTI substitution for a PI may favour immune reconstitution with an improvement in HIV-1-specific responses, which may reflect differential effects on antigen processing and presentation, an autovaccination effect or alternatively a potential suppressive effect of the PI.

Causes of death among HIV-infected patients in the era of highly active antiretroviral therapy, Bordeaux, France, 1998-1999

OBJECTIVES

To describe the causes of death in HIV-infected patients in the era of highly active antiretroviral therapy (HAART).

METHOD

A retrospective survey conducted in Bordeaux, France. Medical records of all deaths that had occurred in 1998 and 1999 amongst patients followed within the Aquitaine cohort were reviewed by the same physician. Immediate and underlying causes of death were described, taking into account the morbidity at the time of death.

RESULTS

Sixty-six deaths occurred in 1998, and 41 in 1999. Sixty-seven per cent of deceased patients were male. Median age at time of death was 43 years (range 25-71), median CD4 was 162 cells/microL (0-957); 28% of patients had a CD4 count > 200 cells/microL and 7% plasma viral load < 500 HIV-RNA copies/mL. Amongst morbidity present at the time of death, there were 23 bacterial infections, 16 non-Hodgkin's lymphomas, 16 cirrhoses, 15 non HIV-related malignancies, 13 central nervous system diseases and 10 myocardiopathies. The main immediate causes of death were: multiple organ failure (21%), coma (18%), septic shock (15%) and acute respiratory failure (14%). Underlying causes of death were AIDS-defining events (48%), non AIDS HIV-related infection (3%), hepatitis B- or C-associated cirrhosis (14%), non HIV-related malignancies (11%), cardiovascular events (10%), suicide and overdose (6%), treatment-related fatalities (4%), injury (2%) and unknown (2%). Patients dying from AIDS-related events were more often female, had a lower CD4 count, a higher level of HIV-RNA, a shorter history of HIV infection and were less often coinfected with hepatitis B and C viruses than those dying from other underlying causes.

CONCLUSIONS

AIDS-related events are no longer the major causes of death of HIV-infected patients in the era of HAART. This evolving mortality pattern justifies an adaptation of both the epidemiological surveillance and the clinical monitoring of HIV-infected patients.

Factors related to lipodystrophy and metabolic alterations in patients with human immunodeficiency virus infection receiving highly active antiretroviral therapy

Morphologic and metabolic changes associated with protease inhibitor (PI) therapy have been reported since the introduction of PIs for treatment of human immunodeficiency virus infection. These changes were measured 12-20 months after initiation of PI therapy in a cross-sectional study involving 614 patients from the Antiprotéases Cohorte (APROCO) Study (Agence Nationale de Recherches sur le Sida-EP11). The prevalence was 21% for isolated peripheral atrophy, 17% for isolated fat accumulation, 24% for mixed syndrome, 23% for glucose metabolism alterations, 28% for hypertriglyceridemia (triglyceride level, > or =2.2 mM), and 57% for hypercholesterolemia (cholesterol level, > or =5.5 mM). Age was significantly associated with different phenotypes of lipodystrophy and metabolic alterations, but body-mass index, CD4(+) cell count, and type of nucleoside reverse-transcriptase inhibitor or PI received were not constantly associated with these changes. Furthermore, in all models tested, exposure to stavudine was associated with lipoatrophy and exposure of ritonavir was associated with hypertriglyceridemia. Detection and management of these disorders should be implemented to prevent further complications.

Switch studies: a review

Many physicians and patients wish to switch from successful protease inhibitor (PI)-based regimens to alternative regimens, usually composed of a nonnucleoside reverse transcriptase inhibitor (NNRTI) or abacavir plus two nucleoside reverse transcriptase inhibitors (NRTIs). This reflects a desire to avoid or reverse the metabolic changes observed during long-term PI-based antiretroviral therapy; to alleviate PI-associated adverse effects; and to improve adherence by simplifying the regimen. Data from a number of randomized and cohort PI switch studies are reviewed. Overall, the results of these studies are mixed, perhaps because of limitations in study design, patient number and duration of follow-up. In most studies, the frequency of virological failure is reduced by switching to a NNRTI regimen. Switching to an abacavir-based regimen is associated with two-fold higher risk of virological failure if mutations in the reverse transcriptase gene pre-exist. Improvements in metabolic and lipid abnormalities have not been uniform but favourable lipid changes have been reported, particularly after switching to nevirapine. Resolution of lipodystrophy symptoms has not been demonstrated objectively, perhaps because of insufficient follow-up and/or the role of NRTIs in this syndrome.

Cardiovascular disease risk factors in HIV-infected patients in the HAART era

HIV infection is accompanied by disturbances in lipid and glucose metabolism, which are further compounded by changes induced by antiretroviral drugs. There is increasing concern that these changes will lead to an epidemic of cardiovascular disease. Cardiovascular disease will no doubt increase, but current data indicate that the average absolute levels are likely to remain low, although patients with additional risks (smoking, hypertension, diabetes, age, family history, etc.) are certainly more susceptible. The complications of therapy need to be taken into account when deciding on the time of treatment, and reducing risk factors should become a routine aspect of the care of an HIV population that now lives longer as a result of highly active antiretroviral therapy.