High-density lipoprotein cholesterol is low in HIV-infected patients with lipodystrophic fat expansions: implications for pathogenesis of fat redistribution

Biochemical and nutritional evaluation of patients with visceral leishmaniasis before and after treatment with leishmanicidal drugs

INTRODUCTION

Visceral leishmaniasis (VL) is caused by the intracellular protozoan Leishmania donovani complex. VL may be asymptomatic or progressive and is characterized by fever, anemia, weight loss and the enlargement of the spleen and liver. The nutritional status of the patients with VL is a major determinant of the progression, severity and mortality of the disease, as it affects the clinical progression of the disease. Changes in lipoproteins and plasma proteins may have major impacts in the host during infection. Thus, our goal was evaluate the serum total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides, glucose, albumin, globulin and total protein levels, as well as the body composition, of VL patients before and after treatment.

METHODS

Nutritional evaluation was performed using the bioelectrical impedance analysis (BIA) to assess body composition. Biochemical data on the serum total cholesterol, HDL, LDL, triglycerides, glucose, albumin, globulin and total protein were collected from the medical charts of the patients.

RESULTS

BIA indicated that both pre-treatment and post-treatment patients exhibited decreased phase angles compared to the controls, which is indicative of disease. Prior to treatment, the patients exhibited lower levels of total body water compared to the controls. Regarding the biochemical evaluation, patients with active VL exhibited lower levels of total cholesterol, HDL, LDL and albumin and higher triglyceride levels compared to patients after treatment and the controls. Treatment increased the levels of albumin and lipoproteins and decreased the triglyceride levels.

CONCLUSIONS

Our results suggest that patients with active VL present biochemical and nutritional changes that are reversed by treatment.

The Relationship Between HIV Infection and Cardiovascular Disease

Over 30 million people are currently living with human immunodeficiency virus (HIV) infection, and over 2 million new infections occur per year. HIV has been found to directly affect vascular biology resulting in an increased risk of cardiovascular disease compared to uninfected persons. Although HIV infection can now be treated effectively with combination antiretroviral medications, significant toxicities such as hyperlipidemia, diabetes, and excess cardiovascular co-morbidity; as well as the potential for significant drug-drug interactions between HIV and cardiovascular medications, present new challenges for the management of persons infected with HIV. We first review basic principles of HIV pathogenesis and treatment and then discuss relevant clinical management strategies that will be useful for cardiologists who might be involved in the care of HIV infected patients.

Effect of extended-release niacin on hormone-sensitive lipase and lipoprotein lipase in patients with HIV-associated lipodystrophy syndrome

BACKGROUND

HIV-associated lipodystrophy syndrome is strongly associated with antiretroviral treatment in patients with human immunodeficiency virus (HIV). Niacin is thought to affect hormone-sensitive lipase (HSL) and lipoprotein lipase (LPL) expression in peripheral and intra-abdominal fat (IAF).

OBJECTIVE

This study investigated the effect of extended-release niacin (ERN) on adipose HSL and LPL expression in patients with HIV-associated lipodystrophy syndrome.

METHODS

Changes in IAF and peripheral fat content and HSL and LPL expression were examined in 4 HIV-infected patients recruited from a prospective study treated with ERN. Patients underwent limited 8 slice computerized tomography abdominal scans, dual-energy X-ray absorptiometry scans, and skin punch biopsies of the mid-thigh at baseline and after 12 weeks of ERN. All subjects were on stable highly active antiretroviral therapy prior to and during the study. Changes in body habitus were self-reported.

RESULTS

Normalized HSL expression decreased in 3 patients and normalized LPL expression increased in all 4 patients when comparing pre- and post-ERN treated samples. All subjects showed a decrease in total cholesterol (TC) and triglyceride (TG) levels.

CONCLUSIONS

Preliminary analysis suggests ERN may induce changes in HSL and LPL expression. This method is a feasible approach to identify changes in adipose RNA expression involved with lipolysis.

Lipid metabolism in treated HIV Infection

Patients infected with the human immunodeficiency virus (HIV) are prone to a great number of lipid and lipoprotein disturbances, as a result of both the infection itself and direct effects on lipid metabolism from the drugs used to treat HIV infection. These lipid disorders account for at least part of the increased risk of cardiovascular disease seen in this population. In general, evaluation and interventions for dyslipidemia in HIV-infected individuals should follow guidelines established for the general population. Special consideration, however, must be given to the potential for adverse drug interactions between lipid lowering drugs and the agents used to treat HIV infection. In this review, we summarize what is known about the relative tendency of different antiretroviral drugs to alter lipid levels, and suggest an approach to intervention for dyslipidemia in this population.

Human immunodeficiency virus and highly active antiretroviral therapy-associated metabolic disorders and risk factors for cardiovascular disease

The successful introduction of highly active antiretroviral therapy (HAART), a combination of potent antiretroviral agents, including protease inhibitors, nucleoside reverse transcriptase inhibitors, and nonnucleoside reverse transcriptase inhibitors, has impacted positively on morbidity and mortality among human immunodeficiency virus (HIV)-positive patients. Over time, HAART has been associated with a number of metabolic and anthropometric abnormalities, including dyslipidemia and insulin resistance as well as subcutaneous fat loss and abdominal obesity, potentially contributing to cardiovascular risk. Recent studies have more firmly established that both HIV infection and HAART might increase the risk of clinical cardiovascular events. Furthermore, whereas HIV/HAART is associated with multiple aspects of endocrine dysfunction, there has been less focus on bone disease, although some studies indicate a higher prevalence of osteoporosis among HIV-positive subjects compared to HIV-negative controls. The relationship between bone and fat metabolism under HIV-positive conditions deserves further attention, and available data suggest the possibility of an intriguing connection. In the future, an increasing population of aging HIV-positive patients with a spectrum of antiretroviral therapies and accumulation of endocrine abnormalities and conventional cardiovascular risk factors will present preventive and therapeutic challenges to our health-care system.

Severe HIV-associated hypertriglyceridaemia treated with rosuvastatin plus omega-3 fatty acids

Compared with healthy controls, HIV patients already have abnormal lipoprotein concentrations before the initiation of highly active antiretroviral therapy (HAART), which worsen with the therapy. HAART-associated dyslipidaemia features fundamental proatherogenic changes such as increased plasma triglycerides (TGs), increased total cholesterol and low-density lipoprotein cholesterol as well as decreased high-density lipoprotein cholesterol (HDL-C). The current guidelines for managing HIV-associated dyslipidaemia recommend diet and exercise counselling, alteration of HAART regimen or addition of lipid-lowering medications such as statins, fibrates and omega-3 (OM-3) fatty acids. Given that cardiovascular risk significantly increases with elevated lipid levels, selecting a drug to manage dyslipidaemia is particularly important. A case is described of an HIV patient who had severe hypertriglyceridaemia and bad metabolic parameters treated with rosuvastatin and OM-3 fatty acids. So we obtained a more marked reduction of TG levels than has never been described before in the literature, associated with a significant increase in HDL-C levels.

The fatty acid binding protein-4 (FABP4) is a strong biomarker of metabolic syndrome and lipodystrophy in HIV-infected patients

BACKGROUND

The incidence of metabolic abnormalities in HIV-infected patients is increasing. Fatty acid binding protein-4 (FABP4) is an emerging biomarker for metabolic-related disturbances. We aimed to study FABP4 as a marker of metabolic syndrome (MS) or lipodystrophy (LD) in HIV patients.

METHODS

FABP4 plasma concentrations were measured by enzyme-linked immunoassays in 183 HIV-infected patients, enrolled as part of a study aimed at identifying predictors of atherosclerosis. The presence of MS or LD was diagnosed according to standard clinical methods. Univariate and multivariate statistical analyses were performed.

RESULTS

FABP4 concentration was significantly higher in those patients with either MS or LD criteria than those without any metabolic disturbance. Similarly, FABP4 concentration significantly increased with an increasing of MS features and was strongly correlated with body-mass index, triglycerides, HDL-cholesterol concentrations, insulin and blood pressure. Patients in the highest quartile of FABP4 presented a six-fold increased odds ratio for MS and a three-fold increased odds for LD, adjusted by age, sex, body-mass index and the antiretroviral therapy.

CONCLUSIONS

FABP4 is a strong plasma marker of metabolic disturbances in HIV-infected patients, and therefore, could serve to guide therapeutic intervention in this group of patients.

Heart positive: design of a randomized controlled clinical trial of intensive lifestyle intervention, niacin and fenofibrate for HIV lipodystrophy/dyslipidemia

Dyslipidemia and insulin resistance occur in a large proportion of HIV-infected patients treated with highly active antiretroviral therapy (HAART); anthropomorphic changes, such as lipoatrophy and central obesity, occur in a subset of patients. This cluster of clinical features, which is termed HIV lipodystrophy, places patients at increased risk for cardiovascular disease. Currently, there is no consensus on the appropriate therapy for the management of HIV lipodystrophy for which the underlying defects are enhanced lipolysis, impaired fat oxidation, increased hepatic VLDL-triglyceride synthesis and secretion, and impaired disposal of intestinally-derived lipoprotein-triglycerides. We describe the design of a randomized, placebo-controlled trial to compare the effects of usual care to diet, exercise and lipid-lowering drugs on lipid profiles of patients with HIV lipodystrophy. The trial will randomize 200 patients into five groups. Outcomes of usual care, diet and exercise alone or in combination with niacin, fenofibrate or both medications will be compared after six months. Unique aspects of the design include an interactive Internet Diet Management system to increase ATP-III recommended dietary compliance for metabolic syndrome, and a supervised program of aerobic and resistance exercises. The study is powered to detect a 20% decrease in triglycerides with the lifestyle intervention and an additional 20% improvement with the addition of niacin and/or fenofibrate. Secondary outcomes include assessment of lipid profile changes, LDL and HDL particle size, plasma cholesterol ester transport protein activity, visceral and subcutaneous fat distribution, glucose tolerance, insulin resistance, and leptin and adiponectin levels.

Use of recombinant human growth hormone in HIV-associated lipodystrophy

PURPOSE OF REVIEW

In the past few years there has been great interest in potential interventions for the body shape abnormalities in HIV-infected individuals that have been termed the HIV-associated lipodystrophy syndrome. This review examines the studies that have focused on the effects of recombinant human growth hormone as a treatment for the central fat accumulation that is part of this syndrome.

RECENT FINDINGS

A recent placebo-controlled trial confirmed that growth hormone leads to a significant dose-dependent improvement in trunk or visceral fat. These improvements were accompanied by dose-dependent side-effects, including glucose intolerance/insulin resistance and tissue edema. With the improvements seen with growth hormone treatment, the patient's body image and sense of well-being also improved. Recent novel data suggest that the use of growth hormone-releasing hormone may possibly be an alternative to treating HIV lipodystrophy with recombinant human growth hormone, because it appears to have fewer adverse events and results in the same benefits in HIV-infected patients with central fat deposition.

SUMMARY

Growth hormone has been shown to lead to a dose-dependent improvement in patients with HIV-associated visceral fat accumulation. Treatment with growth hormone has been complicated by predictable and dose-dependent side-effects. The optimal dose and duration of treatment with growth hormone is not known.

Abnormalities in apolipoprotein and lipid levels in an HIV-infected Brazilian population under different treatment profiles: the relevance of apolipoprotein E genotypes and immunological status

HIV infection is associated with disturbances in lipid metabolism due to a host's response mechanism and the current antiretroviral therapy. The pathological appearance and progression of atherosclerosis is dependent on the presence of injurious agents in the vascular endothelium and variations in different subsets of candidate genes. Therefore, the Hha I polymorphism in the apolipoprotein E gene was evaluated in addition to triglycerides, total cholesterol, very low-density lipoprotein (VLDL), LDL, high-density lipoprotein (HDL), and apolipoprotein (apo) Al, B and E levels in 86 Brazilian HIV-infected patients and 29 healthy controls. The allele frequency for apoE in the HIV-infected group and controls was in agreement with data on the Brazilian population. Dyslipidemia was observed in the HIV group and verified by increased levels of triglycerides, VLDL and apoE, and decreased levels of HDL and apoAl. The greatest abnormalities in these biochemical variables were shown in the HIV-infected individuals whose immune function was more compromised. The effect of the genetic variation at the APOE gene on biochemical variables was more pronounced in the HIV-infected individuals who carried the apoE2/3 genotype. The highly active anti-retroviral therapy (HAART)-receiving group presented increased levels of total cholesterol and apoE. Dyslipidemia was a predictable consequence of HIV infection and the protease inhibitors intensified the increase in apoE values.

Treatment of metabolic syndrome

The metabolic syndrome is intended to identify patients who have increased risk of diabetes and/or a cardiac event due to the deleterious effects of weight gain, sedentary lifestyle, and/or an atherogenic diet. The National Cholesterol Education Program's Adult Treatment Panel III definition uses easily measured clinical findings of increased abdominal circumference, elevated triglycerides, low high-density lipoprotein-cholesterol, elevated fasting blood glucose and/or elevated blood pressure. Three of these five are required for diagnosis. The authors also note that other definitions of metabolic syndrome focus more on insulin resistance and its key role in this syndrome. This review focuses on how treatment might affect each of the five components. Abdominal obesity can be treated with a variety of lower calorie diets along with regular exercise. Indeed, all of the five components of the metabolic syndrome are improved by even modest amounts of weight loss achieved with diet and exercise. For those with impaired fasting glucose tolerance, there is good evidence that a high fiber, low saturated fat diet with increased daily exercise can reduce the incidence of diabetes by almost 60%. Of note, subjects who exercise the most, gain the most benefit. Metformin has also been shown to be helpful in these subjects. Thiazolidinedione drugs may prove useful, but further studies are needed. Although intensified therapeutic lifestyle change will help the abnormal lipid profile, some patients may require drug therapy. This review also discusses the use of statins, fibrates, and niacin. Likewise, while hypertension in the metabolic syndrome benefits from therapeutic lifestyle change, physicians should also consider angiotensin converting enzyme inhibitor drugs or angiotensin receptor blockers, due to their effects on preventing complications of diabetes, such as progression of diabetic nephropathy and due to their effects on regression of left ventricular hypertrophy. Aspirin should be considered in those with at least a 10% risk of a coronary event over 10 years. Finally, three related conditions, nonalcoholic fatty liver disease, polycystic ovary syndrome and protease inhibitor associated lipodystrophy improve with therapeutic lifestyle change. Although metformin is shown to be useful with polycystic ovary syndrome, the data supporting drug therapy for the other syndromes is less convincing. More robust studies are needed before any firm recommendations can be made.

Management of Dyslipidaemia in HIV-Infected Patients Receiving Antiretroviral Therapy

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

Effects of growth hormone on abnormal visceral adipose tissue accumulation and dyslipidemia in HIV-infected patients

BACKGROUND

Some HIV-infected patients develop fat maldistribution with visceral adipose tissue (VAT) accumulation and metabolic abnormalities. No medical treatment is approved by the US Food and Drug Administration to reduce VAT.

METHODS

In this double-blind trial, 245 HIV-infected patients with excess VAT were randomized to receive placebo (PL), recombinant human growth hormone (r-hGH) at a dose of 4 mg daily (DD) or 4 mg on alternate days (AD) for 12 weeks. For weeks 12 to 24, DD patients were rerandomized to PL (DD-PL) or AD (DD-AD), AD patients continued on AD (AD-AD), and PL patients were switched to DD (PL-DD).

RESULTS

From baseline to week 12, VAT decreased significantly compared with PL in DD (-8.6%, P < 0.001) but not in AD (-4.2%, P = 0.052). Trunk-to-limb fat ratio decreased significantly in both (P < 0.001) compared with PL, as did total cholesterol and non-high-density lipoprotein (HDL) cholesterol (-4.5% and -7.5% in DD, -4.3% and -6.2% in AD). At week 24, all groups displayed significant (P < 0.05) reductions in VAT (-5.3% to -9.5%) and trunk fat (-7.8% to -22.8%). DD-AD and AD-AD also displayed significant (P < 0.05) reductions in non-HDL cholesterol.

CONCLUSIONS

These results suggest that r-hGH dosed at 4 mg daily for 12 weeks decreases VAT and cholesterol concentrations in HIV-infected patients with excess VAT. The optimal regimen to sustain these effects awaits determination.

Pathophysiology of dyslipidemia and increased cardiovascular risk in HIV lipodystrophy: a model of 'systemic steatosis'

PURPOSE OF REVIEW

This review addresses a syndrome of dyslipidemia and lipodystrophy that has emerged in HIV-infected patients receiving highly active antiretroviral therapy (HAART). The term 'HIV/HAART associated dyslipidemic lipodystrophy (HADL)' describes this syndrome. Although HAART increases patient survival rates, their increased longevity and dyslipidemias place them at risk for cardiovascular disease. Identification of rationally based therapies requires an understanding of the mechanistic basis of HADL.

RECENT FINDINGS

A case definition for HIV lipodystrophy, based on age, gender, duration of HIV disease, serum HDL cholesterol and anthropometry, provides high diagnostic sensitivity and specificity. The dyslipidemias, mainly hypercholesterolemia, hypertriglyceridemia and low-plasma HDL cholesterol, among HIV-infected patients in the pre- and post-HAART eras are summarized. Clinical studies of HADL patients show increased lipolysis, which increases free fatty acid transfer to liver for incorporation into lipoprotein triglycerides that are secreted, and to skeletal muscle where they impair normal insulin signaling. A model of HADL that includes preferential lipolysis in femoral-gluteal fat depots is presented. Relevant therapies include those that inhibit lipolysis (niacin) or increase hepatic fatty acid oxidation (fibrates).

SUMMARY

HADL is one of several disorders characterized by dyslipidemia, insulin resistance, and lipodystrophy. The relative acuteness of HADL should facilitate identification of the sequence of metabolic changes that gives rise to the syndrome. Current evidence suggests that deranged energy storage in femoral-gluteal and other peripheral sites is important; the molecular details for the derangement are unknown but are under scrutiny by many investigators.

Nicotinamide: an oral antimicrobial agent with activity against both Mycobacterium tuberculosis and human immunodeficiency virus

Coinfection with Mycobacterium tuberculosis and human immunodeficiency virus (HIV) is responsible for one-third of all deaths due to acquired immunodeficiency syndrome. More than 99% of cases of HIV-M. tuberculosis coinfection occur in the developing world, where limited resources add urgency to the search for effective and affordable therapies. Although antimicrobial agents against each of these infections are available, single agents that have activity against both M. tuberculosis and HIV are uncommon. The activity of nicotinamide has been evaluated in 2 different eras: in anti-M. tuberculosis studies performed during 1945-1961 and in anti-HIV studies performed from 1991 to the present. This review brings together these 2 bodies of inquiry and raises the possibility that, with more study, this small molecule could emerge at the beginning of the 21st century either as a therapeutic agent in itself or as the lead compound for a new class of agents with activity against both M. tuberculosis and HIV.