Lipid Profiles in HIV‐Infected Patients Receiving Combination Antiretroviral Therapy: Are Different Antiretroviral Drugs Associated with Different Lipid Profiles?

Long-Term Body Composition and Metabolic Changes in Antiretroviral Naive Persons Randomized to Protease Inhibitor-, Nonnucleoside Reverse Transcriptase Inhibitor-, or Protease Inhibitor Plus Nonnucleoside Reverse Transcriptase Inhibitor-Based Strategy

OBJECTIVE

To assess changes in metabolic parameters and body composition among 422 antiretroviral-naive patients randomized to 3 antiretroviral therapy (ART) strategies: protease inhibitor (PI; n = 141)-, nonnucleoside reverse transcriptase inhibitor (NNRTI; n = 141)-, or PI + NNRTI (n = 140)-based strategies with a median follow-up of 5 years.

METHODS

At baseline and 1-month (metabolic parameters only) and 4-month follow-up intervals, fat-free mass (FFM) and total body fat were calculated, anthropometric measurements were performed, and fasting metabolic parameters were obtained. Rates of change and mean change were compared.

RESULTS

The PI + NNRTI strategy resulted in greater increases in triglycerides and low-density lipoprotein cholesterol compared with the PI and the NNRTI strategies (P < 0.005), with no differences between the PI and NNRTI strategies. High-density lipoprotein cholesterol increased significantly more in the NNRTI strategy than in the PI strategy (P < 0.005). Insulin and insulin resistance increased similarly with all 3 strategies. Changes in total and regional body composition (loss of subcutaneous tissue area and gains in FFM, nonsubcutaneous tissue area, and visceral tissue area) were observed but did not differ by strategy.

CONCLUSIONS

Long-term follow-up of participants initiating 3 ART strategies demonstrated similar changes in total and regional fat, with no differences by ART strategy. The differential effects on lipid metabolism by strategy and the overall increases in insulin and insulin resistance with all 3 strategies necessitate close monitoring of patients on ART.

Efavirenz: a review

Efavirenz is a non-nucleoside reverse transcriptase inhibitor that in most treatment guidelines is recommended to be taken combined with two nucleoside analogue reverse transcriptase inhibitors, as a preferred first-line regimen for the treatment of HIV-1 infection. The antiretroviral efficacy of efavirenz-based combination regimens is good, as has been demonstrated in many clinical trials. Efavirenz has a long plasma half-life, which allows for once-daily dosing, but, as a consequence of this and the low genetic barrier, it is also prone to select for viral resistance when adherence to therapy is suboptimal. The most frequently encountered side effects are neuropsychiatric symptoms. These side effects are usually transient, but have been shown to persist for up to 2 years after initiation of therapy in some patients. This review outlines important and recent pharmacological and clinical data, which explain why efavirenz became a component of preferred treatment regimens today.

HAART and the heart: changes in coronary risk factors and implications for coronary risk in men starting antiretroviral therapy

OBJECTIVES

To estimate changes in coronary risk factors and their implications for coronary heart disease (CHD) rates in men starting highly active antiretroviral therapy (HAART).

METHODS

Men participating in the Swiss HIV Cohort Study with measurements of coronary risk factors both before and up to 3 years after starting HAART were identified. Fractional polynomial regression was used to graph associations between risk factors and time on HAART. Mean risk factor changes associated with starting HAART were estimated using multilevel models. A prognostic model was used to predict corresponding CHD rate ratios.

RESULTS

Of 556 eligible men, 259 (47%) started a nonnucleoside reverse transcriptase inhibitor (NNRTI) and 297 a protease inhibitor (PI) based regimen. Levels of most risk factors increased sharply during the first 3 months on HAART, then more slowly. Increases were greater with PI- than NNRTI-based HAART for total cholesterol (1.18 vs. 0.98 mmol L(-1)), systolic blood pressure (3.6 vs. 0 mmHg) and BMI (1.04 vs. 0.55 kg m(2)) but not HDL cholesterol (0.24 vs. 0.32 mmol L(-1)) or glucose (1.02 vs. 1.03 mmol L(-1)). Predicted CHD rate ratios were 1.40 (95% CI 1.13-1.75) and 1.17 (0.95-1.47) for PI- and NNRTI-based HAART respectively.

CONCLUSIONS

Coronary heart disease rates will increase in a majority of patients starting HAART: however the increases corresponding to typical changes in risk factors are relatively modest and could be offset by lifestyle changes.

Mitigation of antiretroviral-induced hyperlipidemia by hepatitis C virus co-infection

BACKGROUND

Hyperlipidemia is a recognized complication of HIV antiretroviral therapy. The interactions between HIV, hepatitis C virus (HCV), antiretroviral agents and lipids are not well understood.

METHODS

We evaluated the lipid data of patients receiving antiretroviral therapy at the Ottawa Hospital Immunodeficiency Clinic between January 1996 and June 2005 using a clinic database.

RESULTS

A total of 357 HIV-mono-infected and 115 HIV/HCV-co-infected patients were evaluated. The mean changes in total cholesterol (mmol/l) from baseline to months 6 and 12 were 1.00 and 1.24 in HIV mono-infection, and 0.19 (P < 0.001) and 0.01 (P < 0.001) in HIV/HCV, respectively. Metabolic complications including hypercholesterolemia resulted in the interruption of HAART in HIV mono-infection (8%), but not in those with HIV/HCV (< 1%; P < 0.001). Eight per cent of HIV-mono-infected and no co-infected patients initiated lipid-lowering therapy while on their initial course of HAART (P < 0.001). Total cholesterol increased by 0.85 mmol/l in HIV/HCV-co-infected recipients of interferon-based HCV treatment achieving a sustained virological response (SVR), but did not change in those who did not achieve a SVR.

CONCLUSION

HCV co-infection appears to confer a degree of protection from HAART-related lipid complications. The mechanism of this finding deserves evaluation. The implications of this observation for long-term cardiovascular disease risk remains a pressing issue.

Ritonavir-Boosted Protease Inhibitors: Impact of Ritonavir on Toxicities in Treatment-Experienced Patients

The purpose of this review is to discuss the basis for ritonavir boosting of protease inhibitors as well as the complications and benefits associated with ritonavir boosting when designing an antiretroviral regimen for treatment-experienced patients. Such patients have fewer viable options because of cross-resistance arising from previous regimen failures. Ritonavir administered at a low dose to boost another protease inhibitor may be a useful strategy for achieving virological efficacy while minimizing the toxicities associated with full-dose ritonavir. There may be an increased risk of adverse events associated with increased plasma concentration of the concurrent protease inhibitor. Still, the incidence of these adverse events is generally low, and clinical trials have suggested that they rarely result in discontinuation or alteration of the regimen. In highly treatment-experienced patients in particular, the potential benefits associated with ritonavir boosting usually outweigh the risks.

Management of antiretroviral drug toxicity

PURPOSE OF REVIEW

With the emergence of very potent antiretroviral regimens, the major limitation to the success of treatment is now the tolerability of drugs, which can ultimately affect adherence. It is important, therefore, to review the current understanding on antiretroviral drug toxicity, and examine key recent data that can inform the successful avoidance or management of such toxicities.

RECENT FINDINGS

A common theme of recent research has focussed on the genetic predisposition to important immediate side-effects, such as abacavir hypersensitivity, nevirapine hepatotoxicity, efavirenz neurotoxicity and hyperbilirubinemia with atazanavir. Long-term toxicities such as body-composition changes and hyperlipidemia have been more closely linked to thymidine analogues and certain protease inhibitors. The management of these toxicities has also been clarified by studies addressing switching antiretroviral drugs or specific treatments for metabolic syndromes.

SUMMARY

Recent data emphasize the need for the prevention of antiretroviral toxicity by the avoidance of some drugs in certain genetically predisposed populations or by the avoidance of entire classes if possible. In addition, recent studies emphasize the importance of ongoing research to determine the emergence of additional toxicities, as new drugs emerge and achieve widespread use.

Prevalence of risk factors for cardiovascular disease in HIV-infected patients over time: the Swiss HIV Cohort Study

OBJECTIVE

Metabolic changes caused by antiretroviral therapy (ART) may increase the risk of coronary heart disease (CHD). We evaluated changes in the prevalence of cardiovascular risk factors (CVRFs) and 10-year risk of CHD in a large cohort of HIV-infected individuals.

METHODS

All individuals from the Swiss HIV Cohort Study (SHCS) who completed at least one CVRF questionnaire and for whom laboratory data were available for the period February 2000 to February 2006 were included in the analysis. The presence of a risk factor was determined using cut-offs based on the guidelines of the National Cholesterol Education Program (NCEP ATP III), the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC7), the American Diabetes Association, and the Swiss Society for Cardiology.

RESULTS

Overall, 8,033 individuals completed at least one CVRF questionnaire. The most common CVRFs in the first completed questionnaire were smoking (57.0%), low high-density lipoprotein (HDL) cholesterol (37.2%), high triglycerides (35.7%), and high blood pressure (26.1%). In total, 2.7 and 13.8% of patients were categorized as being at high (>20%) and moderate (10-20%) 10-year risk for CHD, respectively. Over 6 years the percentage of smokers decreased from 61.4 to 47.6% and the percentage of individuals with total cholesterol >6.2 mmol/L decreased from 21.1 to 12.3%. The prevalence of CVRFs and CHD risk was higher in patients currently on ART than in either pretreated or ART-naive patients.

CONCLUSION

During the 6-year observation period, the prevalence of CVRFs remains high in the SHCS. Time trends indicate a decrease in the percentage of smokers and individuals with high cholesterol.

Switch from efavirenz to nevirapine associated with resolution of efavirenz-related neuropsychiatric adverse events and improvement in lipid profiles

In a large HIV-specialty private practice, patients with undetectable or low-grade-positive viral loads with neuropsychiatric side effects or elevated lipids were switched from efavirenz-to nevirapine-based antiretroviral regimens. This is a retrospective analysis of virologic efficacy and changes in adverse neuropsychiatric effects and serum lipid levels after this switch. Forty patients were evaluated. Thirty-six had undetectable viral loads prior to the treatment switch, and their levels remained undetectable after the switch for a median of 25 months (range, 6 to 59 months). Four patients had persistently low-grade-positive viral loads before the switch; viral loads in two of the four patients remained low-grade-positive, while the levels in two patients became undetectable. Twenty patients reporting neuropsychiatric symptoms (depression, anxiety, or fatigue with or without sleep disturbances) before the switch demonstrated significant improvement, with complete resolution of symptoms in 15 patients. Four patients with isolated sleep disturbances had significant improvement. No rash developed in any patient during the switch. Mean lipid levels improved significantly following the switch. Mean total cholesterol decreased 17.8 mg/dL; low-density lipoprotein cholesterol decreased 25.5 mg/dL; triglycerides decreased 70.1 mg/dL; and high-density lipoprotein cholesterol increased 5.3 mg/dL (all p < 0.05). These results demonstrate that patients who are virologically controlled on efavirenz-containing regimens with treatment-associated side effects can be successfully switched to nevirapine-containing therapy with maintenance of virologic control, reduction in neuropsychiatric side effects, and improvement in dyslipidemia.

Cerebrovascular disease in highly active antiretroviral therapy-treated individuals: incidence and risk factors

The occurrence of cerebrovascular events in patients infected by human immunodeficiency virus (HIV) has been traditionally associated with opportunistic infections and tumors, and/or advanced stages of immunosuppression. The current use in the clinical practice of antiretroviral treatment (ART) has been associated with a dramatic reduction of HIV-related mortality. Due to the increase of median age of HIV-infected subjects and to the ART-induced lipid abnormalities, an increasing incidence of vascular complications has been reported in this population. The potential contribution of these novel mechanisms should be considered and added to the classic vascular risk factors in the HIV-infected population and the cardiac abnormalities frequently observed in these patients. Large-scale epidemiological studies are needed to better define the incidence of cerebrovascular events in HIV-infected patients and the factors associated with their occurrence.

Metabolic and Mitochondrial Effects of Switching Antiretroviral-Experienced Patients to Enfuvirtide, Tenofovir and Saquinavir/Ritonavir

Objective

Investigate the metabolic and mitochondrial effects of switching a highly active antiretroviral therapy (HAART) regimen with a high mitochondrial toxicity profile to a HAART with a theoretically low mitochondrial toxicity.

Patients and Methods

Six consecutive HAART-experienced patients receiving at least one dideoxy-nucleoside reverse transcriptase inhibitor (NRTI) switched to enfuvirtide plus tenofovir plus saquinavir/ritonavir (T20+TDF+SQV/r). Blood samples were collected at baseline, 12 and 24 weeks after the switch, and viral load (VL) and lymphocyte CD4+ T-cell count were determined. Metabolic parameters consisted of fasting serum triglycerides, cholesterol (total and fractions), glucose, insulin, C-peptide and lactate. Mitochondrial assessment consisted on mitochondrial DNA (mtDNA) quantification, COX-II mitochondrial protein expression rate, mitochondrial respiratory chain complex III and IV activities, and oxygen consumption in peripheral blood mononuclear cells. For baseline mitochondrial comparisons, we included six HIV-infected patients naive for ART.

Results

Switched patients exhibited a mean increase of 26 CD4+ T-cells/mm3 and a mean decrease of 1.1 log in VL ( P=NS for both). Lactate, lipids and glycaemia remained stable during the study; only insulin levels increased significantly ( P<0.05). Switched patients exhibited, at baseline, low mitochondrial measurements, being significant only for complex III and IV activities with respect to naive patients ( P<0.05 for both). MtDNA content did not rise significantly during the study. However, we observed increases in COX-II mitochondrial protein synthesis (124%, P<0.05), complex III activity (127%, P<0.05), complex IV activity (86%, P=0.37) and oxygen consumption (194%, P<0.05).

Conclusion

Switching a HAART-containing dideoxy-NRTI to T20+TDF+SQV/r minimally alters metabolic parameters and exerts beneficial effects on mitochondrial function at 24 weeks. Mitochondrial improvement should be considered as an additional advantage of this rescue therapy.

Antiretroviral Therapy in HIV-Positive Women Is Associated With Increased Apolipoproteins and Total Cholesterol

OBJECTIVES

Dyslipidemia has become a common problem in HIV disease, especially in patients on combination antiretroviral (ARV) therapy. However, little data are available to evaluate lipid abnormalities in women on ARV therapy.

METHODS

Using a cross-sectional design, the prevalence of abnormal plasma lipid and lipoprotein concentrations as well as other biomarkers for vascular disease was determined in 184 HIV-positive women from 2 HIV clinics in Atlanta during 2002.

RESULTS

Most of the women were African American (89%), with median age of 41 years (range 21-72); 6% were diabetic, 44% smoked, and 67% were overweight. ARV therapy defined the comparison groups that included treatment with a protease inhibitor (PI)-based regimen for more than 3 months in 76 (41%), treatment with a nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimen for more than 3 months in 38 (20%), and no ARV therapy for the past 3 months in 70 (38%). Women being treated with a PI or NNRTI had higher total cholesterol and triglyceride levels than patients on no therapy (P < 0.05 for each). Women treated with either PIs or NNRTIs had significantly higher apolipoprotein B and apolipoprotein C-III levels than patients on no therapy (P < 0.01 for each).

CONCLUSIONS

In this cross-sectional study of HIV-infected women, either PI or NNRTI therapy elevated levels of total cholesterol and specific apolipoproteins. These findings, on a background of an older population with additional risk factors of smoking, obesity, and diabetes, may lead to future atherosclerotic events in these patients.

Sustained improvement of dyslipidaemia in HAART-treated patients replacing stavudine with tenofovir

OBJECTIVE

To describe the 12-month evolution of lipid profile in HIV-infected virologically suppressed patients substituting tenofovir for stavudine.

DESIGN AND METHODS

'Recover' was a prospective, multicenter, switch study conducted at 120 HIV units across Spain designed to identify single nucleoside analogue substitution due to adverse events in real practice. Tenofovir substituted stavudine in 873 adult patients. No other substitutions were allowed. This lipid sub-study included 352 randomly recruited patients with complete follow-up and lipid parameters.

MAIN OUTCOME MEASURES

Changes in fasting levels of total cholesterol (TC), high and low-density lipoprotein cholesterol (HDL-C and LDL-C), and triglycerides (TG) at 48 weeks, and their cardiovascular risk (CVR) translation.

RESULTS

At 48 weeks, there was a sustained reduction in median TC (-17.5 mg/dl; P < 0.001), LDL-C (-8.1 mg/dl; P < 0.001), and TG (-35 mg/dl; P < 0.001). HDL-C remained roughly unchanged (-0.8 mg/dl). Patients with baseline hyperlipidaemia showed greater reductions in LDL-C (-29 mg/dl; P < 0.001) and TG (-76 mg/dl; P < 0.001). The greatest TG reduction was observed in patients with severe hyper-TG (-266 mg/dl; P < 0.001). The estimated 10-year CVR decreased in all patients (P < 0.001), and to a higher extent in patients with baseline hyperlipidaemia. There was a trend towards reduction according to the use of lipid-lowering agents (11.6% to 9,9%; P = non-significant).

CONCLUSIONS

The substitution of tenofovir for stavudine causes a sustained improvement of dyslipidaemia. The reduction, although modest, is robust and sustained over time, and significantly reduces the CVR. This switch strategy is safe and contributes to an improvement in the lipid profile, especially TG, in HAART-treated patients.

Dyslipidemia among perinatally HIV-infected children enrolled in the PACTS-HOPE cohort, 1999-2004: a longitudinal analysis

BACKGROUND

Protease inhibitor (PI)-containing regimens have led to improved survival among HIV-infected children. However, adverse effects, including dyslipidemia, may put children at risk for cardiovascular disease.

METHODS

Serum cholesterol and triglyceride levels were recorded on perinatally HIV-infected children participating in the PACTS-HOPE cohort (1999-2004). Hypercholesterolemia (HC) was defined as cholesterol > or =200 mg/dL and hypertriglyceridemia (HT) as triglycerides >or =150 mg/dL. HC and HT were modeled over time using generalized estimating equations.

RESULTS

For 178 children, 47% met criteria for HC and 67% for HT at least once during the study period. In generalized estimating equation models, PI use, undetectable viral load, and immunologic category 3 were independent predictors of HC. HT was significantly associated with PI use and body mass index (BMI) > or =90th percentile for age and gender. Among children on PI-containing regimens, HC was significantly associated with multiple PIs and undetectable viral load; HT was predicted by body mass index > or =90th percentile and ritonavir use. The prevalence of clinical lipodystrophy was 5.6% (10/178).

CONCLUSIONS

Children on PI-containing regimens have a higher risk of both HC and HT. Lipid levels should be measured regularly in children on antiretroviral treatment. Interventions such as diet, exercise, or lipid-lowering drug therapy may benefit some children.

Long-term safety and efficacy of nevirapine-based approaches in HIV type 1-infected patients

Using a multicenter, cross-sectional, observation study, the long-term safety, metabolic profile, and viral efficacy of nevirapine (NVP)-based approaches in HIV-1-infected patients treated for at least 2 years were assessed. For 4 months, all consecutive HIV-1-infected patients who had been receiving an NVP-containing regimen for at least 2 years were recruited. A total of 613 patients were included with a median follow-up period of 43 months (IQR: 31-51). At baseline, 24.5% (150 patients) were treatment naive, 41.5% (254 patients) switched for simplification purposes, and 34% (209 patients) were failing HAART. Increases by five times or more in AST/ALT values were observed in fewer than 2% of patients. Only 5.7% of all adverse events reported during the investigation were attributable to NVP. The percentage of patients with normal HDL cholesterol levels rose from 17.7% at baseline to 35.4% at the last visit. At the latest time point available for analysis, 76% of naive and 74% of those who had switched had HIV-1 RNA loads of <50 copies/ml, while 59% of salvage patients achieved this level of viral suppression. Factors associated with viral suppression at the latest visit were adequate adherence (OR: 2.58, 95% CI: 0.85-7.78, p < 0.001), first-line treatment (OR: 3.02, 95% CI: 1.52-6.00, p = 0.002), and baseline CD4 cells >400 cells/microl (OR: 2.34, 95% CI: 1.22-4.47, p = 0.010). Exposure to nevirapine for up to 4 years is safe. Liver toxicity is infrequent and generally mild. HDL cholesterol levels consistently increase over time and viral suppression is maintained.

Safe Treatment Interruptions in Patients With Nadir CD4 Counts of More Than 350 Cells/μL

OBJECTIVE

To evaluate clinical, immunologic, and virologic performance of patients with nadir CD4 counts of >350 cells/microL upon treatment interruption.

DESIGN

Randomized, open-label clinical trial of 48 weeks' duration.

METHODS

Patients on effective highly active antiretroviral therapy, with nadir CD4 counts of >350 cells/microL and peak viral loads of <50,000 copies/mL were randomized to continue therapy or to interrupt antiretroviral medication. End points for patients with treatment interruption were CD4 counts of <350 cells/microL, viral loads of >1 log above the pretherapy values, or clinical symptoms attributable to HIV, at which point treatment was restarted. In the continuation group, the end points were virologic failure, opportunistic infections, and treatment discontinuation due to toxicities.

RESULTS

Twenty patients were randomized to stop therapy and 16 patients to continue. Median CD4 counts at baseline were 643 cells/microL for the interruption group and 633 cells/microL for the continuation group. No end points were reached in the interruption group. By week 8, viral load returned to values comparable to those of pretherapy in all patients in the interruption group and remained stable until week 48. CD4 counts dropped in the interruption group (median loss of 156 cells/microL) at week 48. Significant decreases in venous lactate were observed in the interruption group.

CONCLUSIONS

Treatment interruptions in patients with nadir CD4 counts of >350 cells/microL seem safe for at least 48 weeks. Pretherapy viral load appears as a valuable tool to predict its level at week 48.

Associations among race/ethnicity, ApoC-III genotypes, and lipids in HIV-1-infected individuals on antiretroviral therapy

BACKGROUND

Protease inhibitors (PIs) are associated with hypertriglyceridemia and atherogenic dyslipidemia. Identifying HIV-1-infected individuals who are at increased risk of PI-related dyslipidemia will facilitate therapeutic choices that maintain viral suppression while reducing risk of atherosclerotic diseases. Apolipoprotein C-III (apoC-III) gene variants, which vary by race/ethnicity, have been associated with a lipid profile that resembles PI-induced dyslipidemia. However, the association of race/ethnicity, or candidate gene effects across race/ethnicity, with plasma lipid levels in HIV-1-infected individuals, has not been reported.

METHODS AND FINDINGS

A cross-sectional analysis of race/ethnicity, apoC-III/apoA-I genotypes, and PI exposure on plasma lipids was performed in AIDS Clinical Trial Group studies (n = 626). Race/ethnicity was a highly significant predictor of plasma lipids in fully adjusted models. Furthermore, in stratified analyses, the effect of PI exposure appeared to differ across race/ethnicity. Black/non-Hispanic, compared with White/non-Hispanics and Hispanics, had lower plasma triglyceride (TG) levels overall, but the greatest increase in TG levels when exposed to PIs. In Hispanics, current PI antiretroviral therapy (ART) exposure was associated with a significantly smaller increase in TGs among patients with variant alleles at apoC-III-482, -455, and Intron 1, or at a composite apoC-III genotype, compared with patients with the wild-type genotypes.

CONCLUSIONS

In the first pharmacogenetic study of its kind in HIV-1 disease, we found race/ethnic-specific differences in plasma lipid levels on ART, as well as differences in the influence of the apoC-III gene on the development of PI-related hypertriglyceridemia. Given the multi-ethnic distribution of HIV-1 infection, our findings underscore the need for future studies of metabolic and cardiovascular complications of ART that specifically account for racial/ethnic heterogeneity, particularly when assessing candidate gene effects.

Nelfinavir: a review of its use in the management of HIV infection

Nelfinavir (Viracept) is an orally administered protease inhibitor. In combination with other antiretroviral drugs (usually nucleoside reverse transcriptase inhibitors [NRTIs]), nelfinavir produces substantial and sustained reductions in viral load in patients with HIV infection. Nelfinavir may be used in the treatment of adults, adolescents and children aged >or=2 years with HIV infection. It can also be used in pregnancy. Resistance to nelfinavir may develop, but the most common mutation (D30N, appearing mainly in HIV-1 subtype B) does not confer resistance to other protease inhibitors, thereby conserving these agents for later use. Although less effective than lopinavir/ritonavir, the preferred first-line treatment in US guidelines, nelfinavir is positioned as an alternative agent for the treatment of adults and adolescents with HIV infection and is an option for those unable to tolerate other protease inhibitors. Nelfinavir also has a role in the management of pregnant patients as well as paediatric patients with HIV infection.

Boosted versus Unboosted Indinavir with Zidovudine and Lamivudine in Nucleoside Pre-Treated Patients: A Randomized, Open-Label Trial with 112 Weeks of Follow-Up (HIV-Nat 005)

Introduction

The use of HIV protease inhibitors (PIs) in a ritonavir (RTV)-boosted form is now common. However, randomized data comparing boosted with unboosted PI strategies are scarce.

Methods

This randomized, open-label trial compared indinavir (IDV) 800 mg three times daily with IDV/RTV 800/100 mg twice daily, both given with zidovudine (AZT)/lamivudine (3TC) twice daily in individuals with at least 3 months previous AZT experience. The primary endpoint was the time-weighted average change in HIV RNA from baseline. Designed as a 48-week study, follow-up continued until week 112. Primary analysis is by intention to treat.

Results

One hundred and three patients commenced therapy and are included in the analysis. Patients had a median of 29 months past nucleoside reverse transcriptase inhibitor (NRTI) exposure. Baseline median (interquartile range) log10 HIV RNA was 4.0 (3.3–4.5) and CD4+T-cell count 166 (40–323) cells/μl. After 112-weeks of study there was no significant difference observed between arms in the mean (sd) change in time-weighted average HIV RNA from baseline (-1.6 [1.1] HIV RNA copies/week/ml three times daily arm; -1.4 [1.1] HIV RNA copies/week/ml twice daily arm; P=0.3). Both arms were associated with substantial toxicity expressed as serious adverse events and study drug interruptions. The twice daily arm experienced greater dyslipidaemia. Mean (sd) changes in time-weighted CD4+ T-cell count from baseline were similar [88 (84) cells/week/μl three times daily arm; 70 [109] cells/week/μl twice daily arm; P=0.3).

Conclusions

RTV-boosted IDV 800/100 mg twice daily demonstrated comparable efficacy to unboosted IDV 800mg three times daily dosing. Both regimens were associated with substantial toxicity. Use of lower doses of RTV-boosted IDV may result in better tolerability without loss of efficacy and warrant further research.

HIV and Aging

Between 2001 and 2004, the percentage of all HIV cases in patients aged >or=50 years increased from 17% to 23%. This concerning increase is expected to continue over the next decade. The increasing prevalence of HIV in these patients is a result of increased longevity in patients treated with highly active antiretroviral therapy (HAART) as well as new primary infections in older patients. While older patients may achieve virological suppression at the same rate as younger patients, the immunological benefit of HAART in older patients may be reduced compared with younger patients. In addition, the toxicities associated with HAART may be worse in older HIV patients, particularly those with underlying renal or hepatic insufficiency. All previous studies evaluating the virological and immunological benefits of HAART in older patients have had relatively small sample sizes and none has compared efficacy or rates of toxicity by HAART treatment class. Co-morbidities are more common in older than in younger patients and can impact on the management of HIV in these patients. Providers must be cognisant of drug-drug interactions and potential adverse effects of HAART regimens when selecting an ideal antiretroviral regimen for older HIV patients. Given the increased longevity and rates of malignancies in HIV-infected patients, providers should also be particularly vigilant in maintaining routine health screening in older HIV patients. Controlled trials on HIV epidemiology, pathogenesis, and therapeutic and clinical outcomes are also needed in older patients. As the HIV-infected population ages, there is a growing need to better determine the effectiveness of HAART in older patients, and to investigate factors associated with a more rapid course of HIV infection in patients aged >50 years.

The Nurse Practitioner’s Role in Managing Dyslipidemia and Other Cardiovascular Risk Factors in HIV-Infected Patients: Impact of Antiretroviral Therapy

The beneficial effects of antiretroviral therapy (ART) for the treatment of HIV disease have been accompanied by metabolic changes associated with an increased risk of cardiovascular disease. These changes, which include dyslipidemia, change in body fat distribution, and insulin resistance, resemble the symptoms of metabolic syndrome. Protease inhibitors, nucleoside analogue reverse transcriptase inhibitors, and nonnucleoside reverse transcriptase inhibitors have all been associated with dyslipidemia to varying degrees. In addition, patients on ART show an increased risk of myocardial infarction and other cardiovascular events. According to the recommendations of the National Cholesterol Education Program and the Adult AIDS Clinical Trial Group, health care providers should assess cardiovascular risk before starting ART and then continue to monitor lipid levels. Treatment of ART-associated dyslipidemia should follow the following sequence: therapeutic lifestyle changes, lipid-lowering drug therapy, and finally, modifying ART if necessary. By providing education, support, and follow-up care, nurse practitioners can help to implement these steps.

Aging and HIV infection

With the advent of highly active antiretroviral therapy (HAART) in mid-1995, the prognosis for HIV-infected individuals has brightened dramatically. However, the conjunction of potent antiviral therapy and longer life expectancy may engender a variety of health risks that, heretofore, HIV specialists have not had to confront. The long-term effects of HIV infection itself and exposure to antiretroviral agents is unknown. Several aspects of aging, including psychiatric disease, neurocognitive impairment, and metabolic and hormonal disorders, may be influenced by chronic exposure to HIV and/or HIV therapeutics. In this paper, we discuss the health issues confronting HIV-infected older adults and areas for future research.

Risk factors and causes of death in the Australian HIV Observational Database

Introduction: Mortality rates in HIV-infected people remain high in the era of highly active antiretroviral treatment (HAART). The objective of this paper was to examine causes of deaths in the Australian HIV Observational Database (AHOD) and compare risk factors for HIV-related and HIV-unrelated deaths. Methods: Data from AHOD, an observational study of people with HIV attending medical sites between 1999 and 2004, were analysed. Primary and underlying causes of death were ascertained by sites completing a standardised cause of death form. Causes of death were then coded as HIV-related or HIV-unrelated. Risk factors for HIV-related and unrelated deaths were assessed using survival analysis among patients who had a baseline and at least one follow-up CD4 and RNA measure. Results: The AHOD had enrolled 2329 patients between 1999 and 2004. During this time, a total of 105 patients died, with a crude mortality rate of 1.58 per 100 person years. Forty-two (40%) deaths were HIV-related (directly attributable to an AIDS event), 55 (52%) HIV-unrelated (all other causes), and eight had unknown cause of death. Independent risk factors for HIV-related deaths were low CD4 count and receipt of a larger number of antiretroviral treatment combinations. Among HIV-unrelated deaths, low CD4 count and older age were independent risk factors. Conclusions: In AHOD in the HAART era, mortality in people with HIV remains around 10-fold higher than in the general population. In our analyses, HIV-unrelated deaths were associated with more advanced HIV disease in a similar way to HIV-related deaths.

Improvement in Dyslipidaemia after Switching Stavudine to Tenofovir and Replacing Protease Inhibitors with Efavirenz in HIV-Infected Children

Objective

To assess the impact on immunological, virological and metabolic parameters of replacing protease inhibitors (PIs) with efavirenz and replacing stavudine with tenofovir in HIV-infected children.

Methods

A 48-week prospective evaluation of 28 HIV-infected children, with stable undetectable HIV-1 loads, who were taking highly active antiretroviral therapy (HAART) containing lamivudine, stavudine and a PI. Individuals were randomized to switch PI to efavirenz and stavudine to tenofovir at baseline (Group 1) or at week 24 (Group 2). Patient assessment included: clinical evaluation, viral load, CD4+ T-cell count, fasting blood levels and urine samples.

Results

All individuals maintained HIV RNA <50 copies/ml and unchanged CD4+ T-cell count through week 48. In Group 1 individuals, a significant decrease in cholesterol ( P<0.05), cholesterol:high-density lipoprotein (HDL) ratio ( P<0.01) and triglycerides ( P<0.05) was observed 24 and 48 weeks after the switch of HAART. The percentage of Group 1 children with increased cholesterol and triglycerides markedly decreased over the study period (from 43% to 0% and from 36% to 7%, respectively). In Group 2 individuals, unchanged lipids in the 24 weeks prior to the switch of HAART and a significant improvement on cholesterol ( P<0.05), cholesterol:HDL ratio ( P<0.01) and triglycerides ( P<0.05) were observed 24 weeks after the switch of HAART. The percentage of Group 2 children with increased cholesterol and triglycerides markedly decreased 24 weeks after the switch of HAART (from 46% to 7% and from 54% to 0%, respectively). Proteinuria and glucosuria were not detected in any individual. The mean values of serum creatinine, serum phosphorus, serum bicarbonate, estimated glomerular filtration rate, urinary microalbumin/creati-nine, α-1-microglobulin/creatinine ratio and maximal tubular phosphate reabsorption remained unchanged in both groups.

Conclusions

In HIV-infected children, switching PI to efavirenz and stavudine to tenofovir is virologically and immunologically safe, is not associated with renal impairment and provides a significant improvement in lipid profile.

Age and sex modulate metabolic and cardiovascular risk markers of patients after 1 year of highly active antiretroviral therapy (HAART)

OBJECTIVE

Primary aim: To evaluate the modulating effects of age and sex on changes in plasma lipid levels in the response to highly active antiretroviral therapy (HAART). Secondary aim: To study insulin, leptin, adiponectin, E-selectin and P-selectin levels and their relation to demographics.

DESIGN

Comparative, longitudinal, open cohort-study.

SETTING

Tertiary care center at a University Hospital.

METHODS

Eighty-two consecutive HIV-seropositive patients of either sex were enrolled in the study. Subjects were between 19 and 60 years of age and naive to HAART. Patients were treated with nucleoside reverse transcriptase inhibitors (NRTIs) and protease inhibitor(s) (PIs) or reverse transcriptase inhibitors (RTIs) only. Subjects were evaluated at baseline and after 3, 6 and 12 months.

RESULTS

Total cholesterol levels increased in all patients. The greatest increase was seen in patients of older age treated with PI. Male gender was another risk factor for higher cholesterol but also for higher triglyceride levels. Therapy with protease inhibitors and/or stavudine had a negative influence on plasma triglyceride levels. Selectins, adipokines and insulin were less influenced by HAART.

CONCLUSION

Based on the results of this study selection of therapy regimen according to the demographic risk factors sex and age can offer an easy strategy to help to minimize lipid elevations.

Predictors of Hypertension and Changes of Blood Pressure in HIV-Infected Patients

Objective

We assessed predictors of changes in systolic (SBP) and diastolic (DBP) blood pressure during follow-up and of the development of hypertension in HIV-infected individuals.

Methods

International cohort collaborative study (D:A:D) of established prospective cohorts of HIV-1-infected patients. Longitudinal analysis of changes in blood pressure (BP) was performed using mixed effects models in 17170 patients. Predictors of development of hypertension during follow-up (systolic BP ≥140 and/or diastolic BP ≥90 mmHg or initiation of antihypertensive treatment) were assessed using Cox models in 8 984 patients with a normal BP level at baseline.

Results

73548 BP measurements with a median of 4 per patient (interquartile range [IQR]: 2–6) were recorded over a median follow-up of 2.3 years (IQR: 1.5–2.6). Risk factors significantly associated with a development of higher systolic BP and diastolic BP (differences ≥5 mmHg and P-values <0.001) during follow-up were: older age, male sex, higher body mass index (BMI) and use of BP-lowering drugs. In patients with normal BP at baseline, 1186 developed hypertension for an incidence of 72.1 per 1000 person-years (95% confidence interval: 68.2–76.0). Factors associated with development of hypertension were: male sex, higher BMI, older age, higher BP at baseline, high total cholesterol and clinical lipodystrophy. Cumulative duration of exposure to nucleoside reverse transcriptase inhibitors ( P=0.75), protease inhibitors ( P=0.92) as well as type of antiretroviral treatment at baseline ( P=0.18) were not associated with a higher risk of hypertension. Cumulative duration of exposure to non-nucleoside reverse transcriptase inhibitors (NNRTIs) was significantly associated with lower risk of hypertension (hazard ratio=0.78 and 0.67 for those treated ≤10 months and >10 months compared with no exposure; P=0.005).

Conclusions

Increased blood pressure in HIV-infected individuals is associated with established risk factors for hypertension. There was no evidence for an independent deleterious effect of any class of antiretroviral drugs on BP, although the use of NNRTIs was associated with a lower risk of development of hypertension.

HIV antiretroviral agents inhibit protein synthesis and decrease ribosomal protein S6 and 4EBP1 phosphorylation in C2C12 myocytes

Combined antiretroviral drug regimens have promoted clinical, immunologic, and virologic improvements in AIDS patients. Nevertheless, these therapies are associated with derangements in lipid and carbohydrate metabolism. In this study, we examined the effects of a representative protease inhibitor (nelfinavir), a nonnucleoside reverse transcriptase inhibitor (nevirapine), and a nucleoside reverse transcriptase inhibitor (zidovudine) on protein synthesis in skeletal muscle cells. To examine these processes, C2C12 myocytes were treated with increasing concentrations of nelfinavir, nevirapine, or zidovudine for 1 or 2 days, and rates of protein synthesis were determined by measuring [35S]methionine/cysteine incorporation into cellular proteins. Treatment of myocytes with therapeutic concentrations of nelfinavir, nevirapine, or zidovudine for 48 hr decreased protein synthesis by 14-20%. An approximately 60% decline was observed in cells treated with higher concentrations of nevirapine or nelfinavir. In contrast, the basal rate of protein synthesis was not affected when cells were incubated with these compounds for 24 hr. Therapeutic concentrations of nelfinavir and nevirapine did not impair the anabolic effect of insulin on protein synthesis. However, zidovudine suppressed the stimulatory effect of insulin. The decreased protein synthesis induced by nelfinavir and zidovudine was associated with decreases in the phosphorylation of the S6 ribosomal protein (rpS6) and the repressor binding protein 4EBP1, while the inhibitory effect of nevirapine was mainly associated with a decline in phosphorylated 4EBP1. In conclusion, nelfinavir, nevirapine, and zidovudine treatments decreased protein synthesis in myocytes and this effect was correlated with a reduction in the phosphorylation level of proteins that regulate translation initiation.

Nelfinavir in HIV-HCV coinfected patients: a 24-month follow-up in a cohort of 82 patients

This retrospective and longitudinal study evaluated the long-term hepatic tolerance of a nelfinavir (NFV)-antiretroviral combined regimen in 82 patients of the HCV-HIV Cohort of CISIH-Sud of Marseilles. Follow-up data (liver enzyme levels, CD4 cell count, HIV viral load, and metabolic parameters) of patients treated with NFV on inclusion or during the follow-up of the cohort were analyzed under treatment over 24 months. Comparisons were performed with X2 or Kruskal-Wallis tests. At baseline (n = 82), the median exposure to NFV was 4.1 months; 58 patients received NFV combined with NRTI and 24 with NNRTI. The median CD4 cell count was 337/mm3 [interquartile range (IR): 216-480) and 39.7% had an undetectable HIV RNA level. Qualitative HCV PCR was positive in 91% of the patients and 19/51 patients with liver biopsy were F3-F4. Median alanine and aspartate aminotransferase (ALAT, ASAT), gamma-glutamyltransferase (GT), and alkaline phosphatase (ALP) were 46 UI/liter (IR: 36-76), 55 UI/liter (IR: 32-97), 97 UI/liter (IR: 50-194), and 88 UI/liter (IR: 72-104), respectively, with 76% of the patients with ALAT/ASAT grade <2. Median follow-up was 23 months (IR: 13.8-37). No significant difference was observed in the distribution of ALAT, ASAT, GT, and ALP as well as of ALAT/ASAT grades over the 24-month study period. Patients treated with NFV + NNRTI had significantly higher GT and ALP levels at baseline with no significant increase during follow-up. Cholesterol, triglyceride, and glycemia distributions remained stable over time. In conclusion, this study showed a good hepatic and metabolic tolerance of a long-term NFV-combined regimen in HIV-HCV coinfected patients.

Lipids, metabolic syndrome, and risk factors for future cardiovascular disease among HIV-infected patients

The availability of potent combination antiretroviral therapy has changed the long-term prognosis for people living with HIV/AIDS. There is increasing concern, however, about the effect of HIV therapy on lipid disorders and subsequent development of coronary artery disease. Virtually all classes of antiretroviral drugs have been associated with some aspect of atherogenic changes in the lipid profiles. This article reviews the current literature on HIV-associated dyslipidemias and the metabolic syndrome, their potential effect on future coronary heart disease, and reviews strategies for management.

HIV protease inhibitors activate the unfolded protein response in macrophages: implication for atherosclerosis and cardiovascular disease

Human immunodeficiency virus (HIV) protease inhibitors have been successfully used in highly active antiretroviral therapy for HIV-1 infection. Treatment of patients infected with HIV with HIV protease inhibitors is unfortunately associated with a number of clinically significant metabolic abnormalities and an increased risk of premature atherosclerosis and myocardial infarction. However, the cellular/molecular mechanisms of the HIV protease inhibitor-induced lipid dysregulation and atherosclerosis remain elusive. Macrophages are the most prominent cell type present in atherosclerotic lesions and play essential roles in both early lesion development and late lesion complications. In this study, we demonstrate that three different HIV protease inhibitors (ritonavir, indinavir, and atazanavir) induce endoplasmic reticulum stress and activate the unfolded protein response in mouse macrophages. Furthermore, at therapeutic concentrations (5-15 microM), these HIV protease inhibitors were found to increase the levels of transcriptionally active sterol regulatory element binding proteins, decrease endogenous cholesterol esterification, cause the accumulation of free cholesterol in intracellular membranes, deplete endoplasmic reticulum calcium stores, activate caspase-12, and increase apoptosis in macrophages. These findings provide possible cellular mechanisms by which HIV protease inhibitors promote atherosclerosis and cardiovascular disease in HIV-1 infected patients treated with HIV protease inhibitors.

Les désordres lipidiques des patients atteints d’affections causées par le VIH

Before the availability of protease inhibitors, elevated triglyceride levels were frequently observed in patients with advanced-stage HIV infection. Since the addition of protease inhibitors to combination treatments, metabolic side effects (alterations in distribution of adipose tissue and metabolic disorders combining dyslipidemia, insulin-resistance and glucose intolerance) have been observed in HIV-positive patients receiving these treatments. Reverse transcriptase nucleoside inhibitors also provoke metabolic disorders. Dyslipidemia is defined by an increase in triglyceride levels of varying and sometimes major intensity, either isolated or combined with a more moderate increase in LDL-cholesterol, while HDL-cholesterol levels may decrease or remain unchanged. These metabolic alterations are potentially atherogenic and may explain these patients' increased risk of cardiovascular disorders. Their mechanism is complex and not yet clearly elucidated. The infection, the improvement in patients' general health and immune status, and individual predisposing factors are probably involved. Treatment probably plays a major role, since the different drugs in these two classes show effects of clearly different intensity. In vitro and ex vivo studies suggest that protease inhibitors alter adipocyte differentiation and induce insulin resistance. Reverse transcriptase nucleoside inhibitors modify adipocyte metabolism too, promoting tissue atrophy. Endocrine factors (cortisol and growth hormones) are also likely to have a role in this hypertrophy of adipose, especially visceral, tissue. These metabolic abnormalities result mainly from the effects of the antiretroviral drugs, notably protease inhibitors, on the hepatic lipid metabolism and on tissue sensitivity to insulin. Lipodystrophy contributes to these abnormalities, as does the reduction in cytokine secretion by adipose tissue. Management of these metabolic disorders is based primarily on a change in the drug regimen (administration of the least deleterious combinations), followed by standard dietary measures and, when necessary, lipid-lowering agents.

The effects of highly active antiretroviral therapy on albuminuria in HIV-infected persons: results from a randomized trial

BACKGROUND

Human immunodeficiency virus (HIV)-infected patients receiving highly active antiretroviral therapy (HAART) regimens, especially those containing protease inhibitors (PIs), are at increased risk for cardiovascular events. Albuminuria is a known independent predictor for the development of cardiovascular disease and may potentially increase in patients receiving PIs. Alternatively, albuminuria may improve with HAART as a result of treating renal parenchymal HIV infection. Longitudinal studies have not been performed previously addressing the effects of HAART on albuminuria.

METHODS

We evaluated the effects of HAART on albumin to creatinine ratios (ACRs) during the initial 64 weeks of therapy in 68 previously untreated HIV-infected subjects, without pre-existing diagnosed diabetes or hypertension, enrolled in a randomized trial comparing PI-based (n = 32) with non-PI-based (n = 36) HAART regimens. We also estimated the prevalence of albuminuria, defined as an ACR > or =3.4 mg/mmol, in these subjects prior to initiation of HAART.

RESULTS

The changes in ACR over the initial 64 weeks of therapy in those receiving PIs [0.0 mg/mmol (-0.4, 0.3)] and in those not receiving PIs [0.0 mg/mmol (-0.5, 0.3)] were not significantly different. There was also no significant difference in the change in the ACR in the group as a whole. However, albuminuria at baseline was found in seven (10%) subjects. Five of these seven subjects had substantial improvements in ACR, ranging from 45 to 95%, with HAART use; three subjects had resolution of albuminuria. ACR at baseline significantly correlated with the baseline HIV-1 RNA level (r = 0.25; P = 0.04) and negatively with CD4 cell count (r = -0.25; P = 0.04).

CONCLUSION

Albuminuria in HIV-infected, treatment-naïve patients was found more frequently than expected and may be influenced by baseline immune status. Although we did not observe an effect of HAART on ACR during the first 64 weeks of therapy, we cannot exclude the possibility that HAART may be beneficial in those patients with significant albuminuria prior to treatment. Research in larger cohorts is required to investigate more definitively the associations between immune status, antiretroviral therapies and renal function in HIV-infected patients.

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.

Effect of Efavirenz on the Pharmacokinetics of Simvastatin, Atorvastatin, and Pravastatin

Efavirenz (EFV) is associated with hyperlipidemia when used in combination with other antiretroviral drugs. EFV is a mixed inducer/inhibitor of cytochrome P450 (CYP) 3A4 isozyme and may interact with hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors that are primarily metabolized via CYP3A4. To assess the drug-drug interaction of EFV used in combination with simvastatin (SIM), atorvastatin (ATR), or pravastatin (PRA), an open-label trial was conducted in 52 healthy adult HIV-seronegative subjects across AIDS Clinical Trials Group sites in the United States. Subjects received 40 mg of SIM, 10 mg of ATR, or 40 mg of PRA daily on days 0 through 3 and days 15 through 18. EFV was administered daily at a dose of 600 mg on days 4 through 18. SIM, ATR, and PRA concentrations were determined before and after EFV, and EFV concentrations were determined before and after statins. EFV reduced SIM acid exposure (area under the curve at 0 to 24 hours [AUC0-24 h]) by 58% (Wilcoxon signed rank test, P=0.003) and active HMG-CoA reductase inhibitory activity by 60% (P<0.001). EFV reduced ATR exposure by 43% (P<0.001) and the total active ATR exposure by 34% (P=0.005). EFV administration resulted in a 40% decrease in PRA exposure (P=0.005). SIM, ATR, and PRA had no effect on non-steady-state EFV concentrations. In conclusion, EFV, when administered with SIM, ATR, or PRA, can result in significant induction of statin metabolism. The reduced inhibition of HMG-CoA reductase activity during coadministration of EFV may result in diminished antilipid efficacy at usual doses of SIM, ATR, and PRA.

Lipid Profiles for Antiretroviral-Naive Patients Starting Pi- and Nnrti-Based Therapy in the Swiss HIV Cohort Study

Background

Blood lipid abnormalities in patients on highly active antiretroviral therapy (HAART) have been associated with exposure to protease inhibitors (PIs), particularly ritonavir. First therapy with a non-nucleoside reverse transcriptase inhibitor (NNRTI) leads to relatively favourable lipid profiles. We report on medium-term lipid profiles (up to 5 years) for antiretroviral-naive patients starting NNRTI- and PI-based HAART in the Swiss HIV Cohort Study.

Methods

Since April 2000, blood samples taken at visits scheduled every 6 months have been analysed for cholesterol and triglyceride concentrations. For 1065 antiretroviral-naive patients starting HAART after April 2000, we estimated changes in concentration over time using multivariate linear regression with adjustment for baseline covariates, use of lipid-lowering drugs and whether the sample was taken in a fasting state.

Results

Non-high density lipoprotein (HDL) cholesterol levels increase with increasing exposure to either PI- or NNRTI-based therapy, HDL cholesterol levels increase and triglyceride levels decrease with increasing exposure to NNRTI-based therapy, whereas triglyceride levels increase with increasing exposure to PI-based therapy. Between NNRTI-based therapies, there is a slight difference in triglyceride levels, which tend to increase with increasing exposure to efavirenz and to decrease with increasing exposure to nevirapine. Of the three common PI-based therapies, nelfinavir appears to have a relatively favourable lipid profile, with little change with increasing exposure. Of the other two PI therapies, lopinavir with ritonavir has a more favourable profile than indinavir with ritonavir, with smaller increases in both non-HDL cholesterol and triglycerides and an increase in HDL cholesterol. Increasing exposure to abacavir is associated with a decrease in the level of triglycerides.

Conclusion

In general, NNRTI-based therapy is associated with a more favourable lipid profile than PI-based therapy, but different PI-based therapies are associated with very different lipid profiles. Nelfinavir appears to have a relatively favourable lipid profile. Of the two boosted PI therapies, lopinavir appears to have a more favourable lipid profile than indinavir.

Low Density Lipoprotein Apolipoprotein B Metabolism in Treatment-Naive HIV Patients and Patients on Antiretroviral Therapy

Background

Dyslipidaemia and lipodystrophy have been described in treated HIV patients and in a small percentage of untreated HIV patients. Lipodystrophy in these patients has been shown to be associated with a lower expression of low density lipoprotein (LDL) receptors.

Methods

We have investigated the effect of antiretroviral treatment with either a protease inhibitor (PI) or a non-nucleoside reverse transcriptase inhibitor (NNRTI) on body fat distribution and LDL apolipoprotein B (apoB) kinetics in 12 HIV-negative controls and 52 HIV-infected patients, including antiretroviral treatment-naive (TN) patients ( n=13) and patients taking two nucleoside analogues plus either a PI ( n=15) or an NNRTI ( n=24).

Results

LDL cholesterol was not different between groups. Compared with the controls, LDL apoB absolute synthetic rate (ASR) and fractional catabolic rate (FCR) were lower and residence time (RT) was higher in the PI and NNRTI groups ( P<0.05). In the TN patients, LDL ASR was lower ( P<0.05) and there was a trend for a lower FCR and higher RT compared with the controls ( P=0.07). LDL apoB pool size was greater in the PI group compared with the controls ( P<0.05). In the PI group, patients on ritonavir (RTV)-containing regimens had a lower LDL apoB ASR ( P=0.009) and a trend to a lower LDL apoB FCR and increased RT compared with non-RTV-containing PI regimens ( P=0.05). There was a positive correlation between LDL apoB FCR and limb fat/lean body mass ( P=0.004) in all subjects.

Conclusions

Decreased LDL FCR, despite unchanged LDL cholesterol, was demonstrated in both treated and untreated HIV patients. It was more marked with RTV-containing regimens and was associated with reduced limb fat. The increased LDL RT may lead to an increased risk of atherogenesis thus contributing to the risk for cardiovascular disease in these patients.

Mechanism of highly active anti-retroviral therapy-induced hyperlipidemia in HIV-infected individuals

The use of highly active anti-retroviral therapy (HAART) is associated with long-term adverse metabolic events including lipodystrophy, dyslipidemia, and insulin resistance. The purpose of the present study was to prospectively examine the mechanism of HAART-induced hyperlipidemia in HIV-seropositive, HAART-naive men prior to the development of frank lipodystrophy. Patient's (n = 13) weight, BMI, lean mass, and percent fat mass, waist circumference did not change after 8 weeks of treatment with HAART. Plasma FFA concentration was already elevated in HAART-naive patients compared to healthy, untreated, HIV negative control individuals and was further increased after 8 weeks of HAART in the former. Insulin-mediated suppression of plasma FFA concentrations was impaired both prior to and following introduction of HAART, compared to healthy, matched controls. VLDL-apoB and VLDL-TG concentrations rose significantly from normal levels after HAART. Compared to healthy control subjects, VLDL fractional catabolic rate and clearance in HIV-seropositive individuals was reduced by approximately 40%, a defect that was not corrected after HAART. The increase in VLDL after HAART was explained by an increase of VLDL-apoB and VLDL-TG secretion towards normal while the impaired VLDL clearance remained unchanged. We conclude that elevation of circulating VLDL early in the course of HAART is caused by the combination of impaired VLDL clearance already present in HAART-naive HIV-seropositive patients and HAART-mediated increase in VLDL secretion. These changes occur concomitantly with an elevation of plasma free fatty acids but before significant change in body composition.

Body Composition and Metabolic Changes in Antiretroviral-Naive Patients Randomized to Didanosine and Stavudine vs. Abacavir and Lamivudine

Comparisons of body composition and metabolic changes among antiretroviral-naive patients randomly assigned to didanosine and stavudine- (ddI+d4T) vs. abacavir and lamivudine- (ABC+3TC) containing regimens were assessed in a nested substudy of an ongoing multicenter randomized trial. At baseline and every 4 months, body cell mass and total body fat were calculated, anthropometric measurements were performed, and fasting metabolic parameters were obtained. The rates of change (unit/mo) estimated using the slopes of regression lines and overall mean changes from baseline were compared by study assignment. Among 96 patients enrolled, 46 received ddI+d4T- and 50 received ABC+3TC-containing regimens with a median follow-up of 32.4 months. For both study arms, an overall increase in the rates of change was seen for body cell mass. For ddI+d4T, after an initial increase, the rates of change declined for regional fat and total body fat compared with an increase for ABC+3TC, with the 2 arms being significantly different (P<0.05). For high-density lipoprotein cholesterol rates of change, ddI+d4T decreased, while ABC+3TC increased. For both arms, low-density lipoprotein cholesterol decreased, while triglycerides increased. Early and sustained increases in insulin and insulin resistance were seen only for ddI+d4T. In this prospective study, metabolic and body composition changes varied according to whether subjects received ddI+d4T or ABC+3TC.

Atazanavir--a once-daily HIV protease inhibitor that does not cause dyslipidemia in newly treated patients: results from two randomized clinical trials

Protease inhibitor (PI) treatment can result in dyslipidemia in a significant proportion of patients. Atazanavir (ATV) is a once-daily PI that has not been associated with clinically relevant increases in total cholesterol (TC), fasting low-density lipoprotein cholesterol (LDL-C), or fasting triglyceride (TG) concentrations. The objectives of this paper were to evaluate lipid profiles in untreated patients, and investigate the frequency and severity of dyslipidemia in the same individuals after treatment with ATV or nelfinavir (NFV) for 48 weeks. Two multinational, randomized, active-controlled, blinded trials compared the safety and efficacy of ATV and NFV in combination with two nucleoside reverse transcriptase inhibitors (NRTIs) in antiretroviral (ARV)-naive patients. Serum lipid concentrations were analyzed in patients who had available measurements both at baseline and at week 48. Patients who had missing data at either time point were not included. Lipid levels remained within baseline ranges at week 48 with ATV treatment, whereas clinically relevant elevations in TC, fasting LDL-C, and fasting TG concentrations occurred with NFV treatment. Mean changes from pre-treatment baseline in fasting LDL-C ranged from -6 percent to +6 percent in the ATV-treatment groups, and from +27 percent to +31 percent in the NFV-treatment groups. After 48 weeks, there was a substantive increase in the proportion of NFV-treated patients who would be recommended for lipid-lowering treatment by National Cholesterol Education Program (NCEP) guidelines, whereas a lesser proportion of ATV-treated patients would be recommended for lipid-lowering treatment. Atazanavir does not lead to dyslipidemia in ARV-naive patients, and may limit the need for lipid-lowering strategies to reduce the risk of cardiovascular disease.

Substituting abacavir for hyperlipidemia-associated protease inhibitors in HAART regimens improves fasting lipid profiles, maintains virologic suppression, and simplifies treatment

Background

Hyperlipidemia secondary to protease inhibitors (PI) may abate by switching to anti-HIV medications without lipid effects.

Method

An open-label, randomized pilot study compared changes in fasting lipids and HIV-1 RNA in 104 HIV-infected adults with PI-associated hyperlipidemia (fasting serum total cholesterol >200 mg/dL) who were randomized either to a regimen in which their PI was replaced by abacavir 300 mg twice daily (n = 52) or a regimen in which their PI was continued (n = 52) for 28 weeks. All patients had undetectable viral loads (HIV-1 RNA <50 copies/mL) at baseline and were naïve to abacavir and non-nucleoside reverse transcriptase inhibitors.

Results

At baseline, the mean total cholesterol was 243 mg/dL, low density lipoprotein (LDL)-cholesterol 149 mg/dL, high density lipoprotein (HDL)-cholesterol 41 mg/dL, and triglycerides 310 mg/dL. Mean CD4+ cell counts were 551 and 531 cells/mm³ in the abacavir-switch and PI-continuation arms, respectively. At week 28, the abacavir-switch arm had significantly greater least square mean reduction from baseline in total cholesterol (-42 vs -10 mg/dL, P < 0.001), LDL-cholesterol (-14 vs +5 mg/dL, P = 0.016), and triglycerides (-134 vs -36 mg/dL, P = 0.019) than the PI-continuation arm, with no differences in HDL-cholesterol (+0.2 vs +1.3 mg/dL, P = 0.583). A higher proportion of patients in the abacavir-switch arm had decreases in protocol-defined total cholesterol and triglyceride toxicity grades, whereas a smaller proportion had increases in these toxicity grades. At week 28, an intent-to treat: missing = failure analysis showed that the abacavir-switch and PI-continuation arms did not differ significantly with respect to proportion of patients maintaining HIV-1 RNA <400 or <50 copies/mL or adjusted mean change from baseline in CD4+ cell count. Two possible abacavir-related hypersensitivity reactions were reported. No significant changes in glucose, insulin, insulin resistance, C-peptide, or waist-to-hip ratios were observed in either treatment arm, nor were differences in these parameters noted between treatments.

Conclusion

In hyperlipidemic, antiretroviral-experienced patients with HIV-1 RNA levels <50 copies/mL and CD4+ cell counts >500 cells/mm³, substituting abacavir for hyperlipidemia-associated PIs in combination antiretroviral regimens improves lipid profiles and maintains virologic suppression over a 28-week period, and it simplifies treatment.

Antiretrovirals, Part II: Focus on Non-Protease Inhibitor Antiretrovirals (NRTIs, NNRTIs, and Fusion Inhibitors)

The second in a series reviewing the HIV/AIDS antiretroviral drugs. This review summarizes the non-protease inhibitor antiretrovirals: nucleoside and nucleotide analogue reverse transcriptase inhibitors (NRTIs), the nonnucleoside reverse transcriptase inhibitors (NNRTIs), and cell membrane fusion inhibitors. In an overview format for primary care physicians and psychiatrists, this review presents the mechanism of action, side effects, toxicities, and drug interactions of these agents.

Nevirapine and efavirenz elicit different changes in lipid profiles in antiretroviral-therapy-naive patients infected with HIV-1

BACKGROUND

Patients infected with HIV-1 initiating antiretroviral therapy (ART) containing a non-nucleoside reverse transcriptase inhibitor (NNRTI) show presumably fewer atherogenic lipid changes than those initiating most ARTs containing a protease inhibitor. We analysed whether lipid changes differed between the two most commonly used NNRTIs, nevirapine (NVP) and efavirenz (EFV).

METHODS AND FINDINGS

Prospective analysis of lipids and lipoproteins was performed in patients enrolled in the NVP and EFV treatment groups of the 2NN study who remained on allocated treatment during 48 wk of follow-up. Patients were allocated to NVP (n = 417), or EFV (n = 289) in combination with stavudine and lamivudine. The primary endpoint was percentage change over 48 wk in high-density lipoprotein cholesterol (HDL-c), total cholesterol (TC), TC:HDL-c ratio, non-HDL-c, low-density lipoprotein cholesterol, and triglycerides. The increase of HDL-c was significantly larger for patients receiving NVP (42.5%) than for patients receiving EFV (33.7%; p = 0.036), while the increase in TC was lower (26.9% and 31.1%, respectively; p = 0.073), resulting in a decrease of the TC:HDL-c ratio for patients receiving NVP (-4.1%) and an increase for patients receiving EFV (+5.9%; p < 0.001). The increase of non-HDL-c was smaller for patients receiving NVP (24.7%) than for patients receiving EFV (33.6%; p = 0.007), as were the increases of triglycerides (20.1% and 49.0%, respectively; p < 0.001) and low-density lipoprotein cholesterol (35.0% and 40.0%, respectively; p = 0.378). These differences remained, or even increased, after adjusting for changes in HIV-1 RNA and CD4+ cell levels, indicating an effect of the drugs on lipids over and above that which may be explained by suppression of HIV-1 infection. The increases in HDL-c were of the same order of magnitude as those seen with the use of the investigational HDL-c-increasing drugs.

CONCLUSION

NVP-containing ART shows larger increases in HDL-c and decreases in TC:HDL-c ratio than an EFV-containing regimen. Based on these findings, protease-inhibitor-sparing regimens based on non-nucleoside reverse transcriptase inhibitor, particularly those containing NVP, may be expected to result in a reduced risk of coronary heart disease.

Cardio- and cerebrovascular events in HIV-infected persons

OBJECTIVE

Recent results from the D:A:D Study indicated that the incidence of myocardial infarction (MI) increased by 26% per year of exposure to combination antiretroviral treatment (CART). The present study was performed to investigate whether this risk was similar when including other cardio- and cerebro-vascular disease events (CCVE).

DESIGN

D:A:D is an international collaboration of 11 cohorts, following 23 468 HIV-infected patients prospectively at 188 clinics in 21 countries situated in Europe, USA and Australia.

METHODS

The end-point was the occurrence of a first CCVE during prospective follow-up, defined as the first of: acute MI, invasive cardiovascular procedures, stroke, or death from other cardiovascular disease. Relative rates (RR) for CCVE from Poisson regression models and 95% confidence intervals (CI) are reported. All models are adjusted for other risk factors for CCVE, including age, gender, ethnicity, family history, body mass index, and smoking status as well as cohort and HIV transmission group.

RESULTS

Over 36 145 person-years of follow-up, 207 patients experienced at least one CCVE (23.7% fatal). The first event was MI in 126 patients, invasive cardiovascular procedure in 39 patients, stroke in 38 patients, and death from other cardiovascular disease in four patients. The incidence of first CCVE was 5.7 per 1000 person-years [95% confidence interval (CI) 5.0-6.5] and increased with longer exposure to CART (RR per year of exposure, 1.26; 95% CI, 1.14-1.38; P < 0.0001).

CONCLUSION

CART increases the risk of CCVD, and this increase is comparable with how CART affects the risk of MI. This finding is consistent with the hypothesis that atherosclerosis is a side-effect of CART.