Is treatment with ritonavir a risk factor for myocardial infarction in HIV-infected patients?

A retrospective study of the lipid-lowering efficacy and safety of ezetimibe added to hydroxy methylglutaryl coenzyme A reductase therapy in HIV-infected patients with hyperlipidemia

BACKGROUND

Abnormalities in lipid metabolism are a well-described consequence of human immunodeficiency virus (HIV) infection being treated with highly active antiretroviral therapies (HAART).

OBJECTIVE

The purpose of this study is to evaluate the lipid-lowering efficacy and safety of ezetimibe added to existing hydroxy methylglutaryl coenzyme A reductase (statin) therapy in HIV-infected patients with hyperlipidemia.

METHODS

This is a retrospective study utilizing a comprehensive electronic patient registry to identify all adult HIV-infected patients seen at the Dallas Veterans Affairs (VA) Medical Center during a 4-year period from October 1, 2002 through October 1, 2006.

RESULTS

A total of 26 HIV-infected patients initiated on ezetimibe 10 mg were identified, with 14 adult males meeting strict criteria for inclusion. Median age was 54 years (interquartile range [IQR], 45-59) with a median duration of HIV of 13 years, CD4 count of 513 cells/mm(3) (IQR, 289-736), and 9 of 14 patients had undetectable viral loads at baseline. Initiation of ezetimibe 10 mg resulted in a significant decrease in total cholesterol (TC) from baseline (-12.9%, P = 0.001); low-density lipoprotein cholesterol (LDL-C; -25.7%, P = 0.001); and non-high-density lipoprotein cholesterol (non-HDL-C; -23.9%, P = 0.001). There was also a nonsignificant decrease in triglycerides (15.8%, P = 0.43), and an increase in number of patients achieving National Cholesterol Education Program/Adult Treatment Panel III goal for LDL-C after initiation of ezetimibe (+20.9%, P = 0.125). These improvements occurred without adverse effects or changes in virologic and immunologic control.

CONCLUSION

Addition of ezetimibe to existing statin therapy in HIV-infected VA patients treated with HAART significantly reduces TC, LDL-C, and non-HDL-C concentrations without apparent side effects or compromising of virologic control.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Hypertriglyceridemia and hypercholesterolemia in human immunodeficiency virus-1-infected children treated with protease inhibitors

BACKGROUND

Adverse effects associated with highly active antiretroviral therapy (HAART), particularly protease inhibitors (PIs), have been identified in adult and pediatric patients. In this study, we monitored, for cholesterol and triglyceride levels, a cohort of HIV-1-infected children receiving a HAART regimen.

METHODS

HIV-infected patients <17 years old belonging to a cohort that has been followed since 1997 were enrolled in the study. Patients were receiving either a three- or four-drug antiretroviral regimen that included two nucleoside reverse transcriptase inhibitors (lamivudine and zidovudine) combined with one or two PIs (ritonavir and/or saquinavir). Cholesterol and triglyceride levels were measured on fasting serum samples drawn at the time of enrollment and every 3 months thereafter. Clinical evaluation was performed on a monthly basis.

RESULTS

Twenty four patients were included. Median age at HIV infection diagnosis was 15 months. Twenty one patients received a four-drug antiretroviral regimen, while three patients received ritonavir plus zidovudine and lamivudine. Median follow-up was 27 months; 62.5% of patients had hypercholesterolemia and 79.2% had hypertriglyceridemia, most typically after 15 months of treatment. None of the patients had physical changes in body fat distribution suggesting lipodystrophy.

CONCLUSIONS

Hyperlipidemia is a frequent complication in HIV-1-infected children undergoing antiretroviral treatment that includes PIs. Additional studies with larger cohorts and a longer follow-up are needed to propose a rationale and alternatives for patients who develop dyslipidemia while receiving PIs.

Metabolic complications associated with HIV protease inhibitor therapy

HIV protease inhibitors were introduced into clinical practice over 7 years ago as an important component of combination antiretroviral drug regimens which in many ways revolutionised the treatment of HIV infection. The significant improvements in prognosis that have resulted from the use of these regimens, combined with the need for lifelong treatment, have increasingly focused attention on the adverse effects of antiretroviral drugs and on the metabolic complications of HIV protease inhibitors in particular. In this review, the cluster of metabolic abnormalities characterised by triglyceride-rich dyslipidaemia and insulin resistance associated with HIV protease inhibitor therapy are considered, along with implications for cardiovascular risk in patients affected by these complications. Toxicity profiles of individual drugs within the HIV protease inhibitor class are examined, as there is an increased recognition of significant intra-class differences both in terms of absolute risk of metabolic complications as well as the particular metabolic phenotype associated with these drugs. Guidelines for clinical assessment and treatment are emphasised, along with pathophysiological mechanisms that may provide a rational basis for the treatment of metabolic complications. Finally, these drug-specific effects are considered within the context of HIV-specific effects on lipid metabolism as well as lifestyle factors that have contributed to a rapidly increasing incidence of similar metabolic syndromes in the general population. These data highlight the importance of individualising patient management in terms of choice of antiretroviral regimen, assessment of metabolic outcomes and use of therapeutic interventions, based on the assessment of baseline (pre-treatment) metabolic status as well as the presence of potentially modifiable cardiovascular risk factors.

Management of protease inhibitor-associated hyperlipidemia

Dyslipidemia, characterized by elevated serum levels of triglycerides and reduced levels of total cholesterol, low-density lipoprotein-cholesterol (LDL-C) and high-density lipoprotein-cholesterol, has been recognized in patients with human immunodeficiency virus (HIV) infection. It is thought that elevated levels of circulating cytokines, such as tumor necrosis factor-alpha and interferon-alpha, may alter lipid metabolism in patients with HIV infection. Protease inhibitors, such as saquinavir, indinavir and ritonavir, have been found to decrease mortality and improve quality of life in patients with HIV infection. However, these drugs have been associated with a syndrome of fat redistribution, insulin resistance, and hyperlipidemia. Elevations in serum total cholesterol and triglyceride levels, along with dyslipidemia that typically occurs in patients with HIV infection, may predispose patients to complications such as premature atherosclerosis and pancreatitis. It has been estimated that hypercholesterolemia and hypertriglyceridemia occur in greater than 50% of protease inhibitor recipients after 2 years of therapy, and that the risk of developing hyperlipidemia increases with the duration of treatment with protease inhibitors. In general, treatment of hyperlipidemia should follow National Cholesterol Education Program guidelines; efforts should be made to modify/control coronary heart disease risk factors (i.e. smoking; hypertension; diabetes mellitus) and maximize lifestyle modifications, primarily dietary intervention and exercise, in these patients. Where indicated, treatment usually consists of either pravastatin or atorvastatin for patients with elevated serum levels of LDL-C and/or total cholesterol. Atorvastatin is more potent in lowering serum total cholesterol and triglycerides compared with other hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, but it is also associated with more drug interactions compared with pravastatin. Simvastatin and lovastatin are significantly metabolized by cytochrome P450 enzymes (CYP3A4) and are therefore not recommended for coadministration with protease inhibitors. A fibric acid derivative (gemfibrozil or fenofibrate) should be used in patients with primary hypertriglyceridemia. However, it must be kept in mind that protease inhibitors, such as nelfinavir and ritonavir, induce enzymes involved in the metabolism of the fibric acid derivatives and may, therefore, reduce the lipid-lowering activity of coadministered gemfibrozil or fenofibrate. In certain patients HMG-CoA reductase inhibitors may be used in combination with fibric acid derivatives but patients should be carefully monitored for liver and skeletal muscle toxicity. Select patients may experience improvements in serum lipid levels when their offending protease inhibitor(s) is/are exchanged for efavirenz, nevirapine, or abacavir; however each patient's virologic and immunologic status must be taken closely into consideration.

Management of dyslipidemias in the age of statins

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

HIV-associated coronary artery disease

Cases, case series, and related articles on coronary artery disease in patients with human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS) identified through a comprehensive literature search were examined for clinical characteristics and angiographic findings of HIV-associated coronary artery disease. Among 129 identified cases, 91% were males. The mean age was 42.3 +/- 10.2 (SD) years (range, 23 to 77 years). The interval between the diagnosis of HIV infection and the diagnosis of coronary artery disease was 72 +/- 60 (SD) months. Degree of immunosuppression was variable (CD4 mean, 313 +/- 209 cells/mm3; range, 6-1070 cells/mm3). There was no correlation between the CD4 cell count and the development and progression of coronary artery disease. Similarly, the development and progression of coronary artery disease was independent of the presence of HIV-related opportunistic infections. Acute myocardial infarction was the initial presentation in 77% of patients. In 76 patients, information on diseased vessels was available: 36 (47%) patients had 3-vessel disease, 14 (18%) patients had 2-vessel disease, and 26 patients (35%) had 1-vessel disease. The left anterior descending artery was involved in 47 (62%) patients while the left circumflex and right coronary arteries were involved in 34 (45%) and 38 (50%) patients, respectively. Thirty-two (25%) patients underwent catheter-based or surgical revascularization. Data were not adequate to assess the prognosis following the acute coronary events or revascularization. The histologic characteristics unique to HIV-associated coronary arteriopathy were diffuse circumferential involvement of the vessel with an unusual proliferation of smooth muscle cells, mixed with abundant elastic fibers, resulting in endoluminal protrusions. Coronary artery disease was a late complication of AIDS.

Evaluation and management of dyslipidemia in patients with HIV infection

OBJECTIVE

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

DESIGN

Systematic review of original research with quantitative synthesis.

MAIN RESULTS

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

CONCLUSIONS

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

Do protease inhibitors increase the risk for coronary heart disease in patients with HIV-1 infection?

There is continued concern about protease inhibitors (PIs) causing increased risk of coronary heart disease (CHD) in HIV-infected patients. This ongoing observational study examines CHD and myocardial infarction (MI) hospitalization rates among HIV-positive members of the Kaiser Permanente Medical Care Program of Northern California, before and after PI use, and before and after any antiretroviral therapy (ART). Also, CHD and MI hospitalization rates among HIV-infected members are compared with members not known to be HIV-positive. With 4.1 years' median total follow-up, age-adjusted CHD and MI hospitalization rates were not significantly different before versus after PIs (6.2 vs. 6.7 events per 1000 person-years); or before versus after ART (5.7 vs. 6.8). However, comparing HIV-positive and -negative members, the CHD hospitalization rate was significantly higher (6.5 vs. 3.8, p =.003), and the difference in the MI rate also was higher (4.3 vs. 2.9, p =.07). Differences between HIV-positive and -negative members in the CHD risk factors measured were mixed, and the overall clinical significance of these differences is uncertain. Our data suggest that PIs and other antiretroviral therapies do not yet increase CHD or MI hospitalizations among HIV-infected individuals; however, longer follow-up is needed. Other HIV-related mechanisms may be at work, causing increased CHD and MI risk among all HIV-infected persons.

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

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

COX-2 selective inhibitors: analysis of the renal effects

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

Long-term efficacy and safety of ritonavir/indinavir at 400/400 mg twice a day in combination with two nucleoside reverse transcriptase inhibitors as first line antiretroviral therapy

OBJECTIVE

To determine the long-term antiretroviral efficacy and tolerability of dual protease inhibitor (PI) therapy with indinavir (IDV)/ritonavir (RTV) at 400/400 mg twice a day (BID) in combination with two nucleoside reverse trancriptase inhibitors (NRTIs).

DESIGN AND METHODS

In an open-label, uncontrolled multicentre clinical trial, antiretroviral therapy naive patients (n = 93) with a high median baseline HIV-1 RNA level of 210 000 copies/mL (range 17 000-2 943 000) and a median CD4 cell count of 195 copies/microL (range 4-656 copies/microL) were started on a regimen of either zidovudine (ZDV)/lamivudine (3TC) (49%), stavudine (d4T)/3TC (38%) or d4T/didanosine (ddI) (14%) plus RTV and IDV, each at 400 mg BID. CD4 cell counts and HIV RNA were determined at 4-week intervals for a duration of 72 weeks. Statistical analysis was performed on treatment as well as by intent to treat, where missing values were counted as failures.

RESULTS

HIV RNA levels below the limit of detection were achieved in 59.5% (< 80 copies/mL) and 63% (< 500 copies/mL) of patients according to the intent to treat analysis at week 72. In the on treatment analysis, the proportion of patients reaching an undetectable viral load was 94.5% (< 80 copies/mL) and 100% (< 500 copies/mL), respectively. Apart from diarrhoea and nausea, serum lipid abnormalities were identified as the most prominent adverse reaction. No cases of nephrotoxicity occurred during the entire observation period of 72 weeks.

CONCLUSIONS

Our results demonstrate that quadruple therapy with RTV/IDV and two NRTIs induces potent, durable and safe HIV suppression and might be particularly beneficial as a first line therapy for patients with a high baseline viral load.

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.

The metabolic puzzle during the evolution of HIV infection

Abnormalities in energy, protein, lipid and glucose metabolism have been described in HIV patients since the beginning of the epidemic. With the new antiretroviral agents, nutritional status and survival have improved dramatically. However, since these therapies were introduced, there have been more descriptions of metabolic abnormalities, some of which were similar to and others of which were in conflict with those reported in previous years. This paper reviews the complexity of the metabolic abnormalities in HIV infections before and after the introduction of highly active antiretroviral therapy, and discusses such etiopathogenic mechanisms as secondary infections, antiretroviral drugs and persistent immune activation, which may be involved in these derangements.

Coronary heart disease associated with the use of human immunodeficiency virus (HIV)-1 protease inhibitors: report of four cases and review

Four cases of human immunodeficiency virus (HIV)-infected patients who developed coronary heart disease (CHD) while under treatment with a protease inhibitor (PI) are described, and the epidemiologic and clinical features of 18 cases reported in the literature are analyzed. Cardiac manifestations mostly included myocardial infarctions. Smoking and hyperlipidemia were the most common risk factors for CHD, reported in 72 and 81% of the patients, respectively. Hypercholesterolemia was observed in 75% of the cases at the time of the cardiovascular event. Ninety percent of the patients with pretreatment normal lipid values experienced a rise in the plasma lipid levels during PI therapy. Although a definite relationship between the development of CHD and HIV PIs can not be made, this analysis suggests that PI-induced hyperlipidemia may play a role in accelerating coronary atherosclerosis in patients with concomitant risk factors. Evaluation and control of risk factors for CHD should be performed in each patient for whom treatment with a PI is indicated.

Antiretroviral Therapy and the Lipodystrophy Syndrome

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

Lipodystrophy syndrome in HIV infection: what is it, what causes it and how can it be managed?

Since the introduction of HIV-1 protease inhibitors as components of antiretroviral drug combination regimens, the clinical course of HIV disease and opportunistic infections has changed dramatically. Besides the favourable virological, immunological and clinical impact of highly active antiretroviral therapy (HAART), several adverse drug reactions have been observed in patients with HIV receiving therapy. Particularly, peripheral lipodystrophy, central adiposity, dyslipidaemia and insulin resistance have been described with a prevalence of up to 80% in patients infected with HIV, and attributed to almost all components of HAART. Hyperlipidaemia is characterised by an increase of low and very low density lipoprotein-cholesterol as well as apolipoproteins B and E. Several studies strongly suggest that there are either multiple syndromes or a variety of factors inducing different changes that influence the ultimate phenotype. Similarities between HIV-associated fat redistribution and metabolic abnormalities with both inherited lipodystrophies and benign symmetric lipomatosis suggest the pathophysiological involvement of, for example, nuclear factors like lamin A/C and drug-induced mitochondrial dysfunction. Moreover, there is some evidence that cytokines and hormones impair fat and glucose homeostasis in patients with HIV receiving HAART. Three years after the first description of HIV therapy-associated abnormal fat redistribution, there is still an ongoing discussion about the case definition, diagnostic procedure and treatment options for both body shape changes and metabolic disturbances. Regarding therapy, there is a major concern about possible complex pharmacological interactions and overlapping adverse effects between HAART and, for example, lipid-lowering therapy. In addition, the likely contribution of both nucleoside analogue reverse transcriptase inhibitors and protease inhibitors to the development of abnormal fat redistribution in patients with HIV limits options of changing to alternative effective antiretroviral drug combinations. Thus, the occurrence of hyperlipidaemia, maturity onset diabetes mellitus, and marked changes in body habitus resulted in important social and clinical consequences such as an increased risk of atherosclerosis. It also sheds new light on the use of protease inhibitors regarding risk factors for the initial treatment decision. In this article, we discuss the features, pathogenesis and treatment options for body fat redistribution and metabolic disturbances associated with HAART in HIV-1 infection.

Management of dyslipidemia in patients with HIV disease

The epidemiological, etiopathogenetic, laboratory and clinical features of serum lipid abnormalities occurring in the course of HIV disease are still poorly understood (especially when the supporting role of single antiretroviral compounds is considered), while limited literature data are to date available regarding the management of HIV-related dyslipidemia, as well as the efficacy and safety of dietary-exercise programs, and that of selected hypolipidemic agents. At this time, a careful monitoring of serum lipid profile is needed during combination antiretroviral therapy including protease inhibitors, in order to suggest a diet and hypolipidemic treatment when applicable, and to prevent clinical sequelae related to long-term dyslipidemia. The selection of an appropriate hypolipidemic agent is difficult, since no controlled studies are available in this field, and possibly increased risks of pharmacologic interactions, toxicity and impaired patient's adherence should be taken into consideration. Waiting for specific guidelines for the treatment of hypertriglyceridemia and hypercholesterolemia in the setting of HIV infection, all available literature reports dealing with the management of HIV-associated hyperlipidemia are briefly discussed, on the basis of personal clinical experience.

Substitution of a nonnucleoside reverse transcriptase inhibitor for a protease inhibitor in the treatment of patients with undetectable plasma human immunodeficiency virus type 1 RNA

Seventy-three patients infected with human immunodeficiency virus type 1 (HIV-1) were enrolled in a prospective observational study to investigate the efficacy and tolerance of substituting a nonnucleoside reverse transcriptase inhibitor (NNRTI) for a protease inhibitor (PI) in patients whose plasma viral load (pVL) was controlled by a PI regimen. After a median follow-up of 52 weeks, 63 patients (86.3%) had undetectable pVLs. The incidence of virological breakthrough at 12 months of follow-up was 6.5% (95% confidence interval [CI], 1-20) among patients who had been antiretroviral naive before receiving HAART and 19.2% (95% CI, 6-34) among patients who had been treated with antiretroviral drugs before receiving the PI regimen (P=.10).

Lipodystrophy syndrome in HIV infection: what is it, what causes it and how can it be managed?

Since the introduction of HIV-1 protease inhibitors as components of antiretroviral drug combination regimens, the clinical course of HIV disease and opportunistic infections has changed dramatically. Besides the favourable virological, immunological and clinical impact of highly active antiretroviral therapy (HAART), several adverse drug reactions have been observed in patients with HIV receiving therapy. Particularly, peripheral lipodystrophy, central adiposity, dyslipidaemia and insulin resistance have been described with a prevalence of up to 80% in patients infected with HIV, and attributed to almost all components of HAART. Hyperlipidaemia is characterised by an increase of low and very low density lipoprotein-cholesterol as well as apolipoproteins B and E. Several studies strongly suggest that there are either multiple syndromes or a variety of factors inducing different changes that influence the ultimate phenotype. Similarities between HIV-associated fat redistribution and metabolic abnormalities with both inherited lipodystrophies and benign symmetric lipomatosis suggest the pathophysiological involvement of, for example, nuclear factors like lamin A/C and drug-induced mitochondrial dysfunction. Moreover, there is some evidence that cytokines and hormones impair fat and glucose homeostasis in patients with HIV receiving HAART. Three years after the first description of HIV therapy-associated abnormal fat redistribution, there is still an ongoing discussion about the case definition, diagnostic procedure and treatment options for both body shape changes and metabolic disturbances. Regarding therapy, there is a major concern about possible complex pharmacological interactions and overlapping adverse effects between HAART and, for example, lipid-lowering therapy. In addition, the likely contribution of both nucleoside analogue reverse transcriptase inhibitors and protease inhibitors to the development of abnormal fat redistribution in patients with HIV limits options of changing to alternative effective antiretroviral drug combinations. Thus, the occurrence of hyperlipidaemia, maturity onset diabetes mellitus, and marked changes in body habitus resulted in important social and clinical consequences such as an increased risk of atherosclerosis. It also sheds new light on the use of protease inhibitors regarding risk factors for the initial treatment decision. In this article, we discuss the features, pathogenesis and treatment options for body fat redistribution and metabolic disturbances associated with HAART in HIV-1 infection.