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

Hepatic steatosis and nonalcoholic fatty liver disease are common and associated with cardiometabolic risk in a primary prevention cohort of people with HIV

BACKGROUND

Hepatic steatosis, including nonalcoholic fatty liver disease (NAFLD), is common among people with HIV (PWH). We present baseline steatosis prevalence and cardiometabolic characteristics among REPRIEVE substudy participants.

METHODS

REPRIEVE is an international, primary cardiovascular disease prevention, randomized, controlled trial of pitavastatin calcium vs. placebo among 7769 PWH ages 40-75 years on antiretroviral therapy (ART) and with low-to-moderate cardiovascular risk. A subset of participants underwent noncontrast computed tomography, with hepatic steatosis defined as mean hepatic attenuation less than 40 HU or liver/spleen ratio less than 1.0, and NAFLD defined as steatosis in the absence of frequent alcohol use or viral hepatitis.

RESULTS

Of 687 evaluable persons, median age was 51 years, BMI 27 kg/m 2 , CD4 + T-cell count 607 cells/μl; 17% natal female sex, 36% Black, 24% Hispanic, and 98% HIV-1 RNA less than 400 copies/ml. Hepatic steatosis prevalence was 22% (149/687), and NAFLD 21% (96/466). Steatosis/NAFLD prevalence was higher in men and with older age, non-Black race, and higher BMI and waist circumference. Both were associated with BMI greater than 30 kg/m 2 , metabolic syndrome components, higher atherosclerotic cardiovascular disease (ASCVD) risk score, HOMA-IR, LpPLA-2 and hs-CRP, and lower high-density lipoprotein cholesterol. Of HIV-specific/ART-specific characteristics, only history of an AIDS-defining illness was more common among persons with steatosis/NAFLD. After adjusting for age, sex and race/ethnicity, BMI greater than 30 kg/m 2 , HOMA-IR greater than 2.0, Metabolic syndrome and each of its components were associated with NAFLD prevalence.

CONCLUSION

In this cohort with controlled HIV and low-to-moderate cardiovascular risk, hepatic steatosis and NAFLD were common and associated with clinically relevant metabolic and inflammatory disturbances but not current HIV-related or ART-related factors.

The Alcohol-High-Density Lipoprotein Athero-Protective Axis

Ingestion of alcohol is associated with numerous changes in human energy metabolism, especially that of plasma lipids and lipoproteins. Regular moderate alcohol consumption is associated with reduced atherosclerotic cardiovascular disease (ASCVD), an effect that has been attributed to the concurrent elevations of plasma high-density lipoprotein-cholesterol (HDL-C) concentrations. More recent evidence has accrued against the hypothesis that raising plasma HDL concentrations prevents ASCVD so that other metabolic processes associated with alcohol consumption have been considered. This review explored the roles of other metabolites induced by alcohol consumption-triglyceride-rich lipoproteins, non-esterified free fatty acids, and acetate, the terminal alcohol metabolite in athero-protection: Current evidence suggests that acetate has a key role in athero-protection but additional studies are needed.

Total thyroidectomy in HIV positive patient with buffalo hump and taurine neck

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A multinodular goiter in an HIV-positive with lipodystrophy, buffalo hump and taurine neck.

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Needle aspiration biopsy was difficult to use to determine the presence of lipodystrophy.

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The goiter was with retrosternal engagement and the ovalization of the tracheal lumen.

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Surgical treatment was necessary due to the presence of dyspnea during exercise.

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Importance of the perioperative teamwork, in particular to the patient positioning.

Background

The authors present a case of multinodular goiter in an HIV-positive patient affected by lipodystrophy with particular accumulation of adipose tissue in the region of the neck and trunk.

Case presentation

The patient, a 53-year-old man, presented with multinodular struma with partial retrosternal engagement, as well as multiple thyroid nodules increasing in size; some of the nodules had suspicious characteristics on ultrasound. Needle aspiration biopsy was difficult to use to determine the presence of lipodystrophy; however, even in the absence of cytology, surgical treatment was necessary due to the presence of dyspnea during exercise, the dimension of the goiter with retrosternal engagement, and the ovalization of the tracheal lumen. The patient underwent total thyroidectomy by anterior cervicotomy with particular attention to patient positioning because of the buffalo hump and taurine neck. Histological examination was positive for adenomatous hyperplasia with outbreaks of papillary microcarcinoma.

Conclusions

The aim of this case report was to highlight the importance of the perioperative teamwork, with particular attention to patient positioning before surgery, as well as professional collaboration and experience among the operators.

Impact of HIV/simian immunodeficiency virus infection and viral proteins on adipose tissue fibrosis and adipogenesis

OBJECTIVE

HIV-infected patients receiving antiretroviral treatment (ART) often present adipose tissue accumulation and/or redistribution. adipose tissue has been shown to be an HIV/SIV reservoir and viral proteins as Tat or Nef can be released by infected immune cells and exert a bystander effect on adipocytes or precursors. Our aim was to demonstrate that SIV/HIV infection per se could alter adipose tissue structure and/or function.

DESIGN

Morphological and functional alterations of subcutaneous (SCAT) and visceral adipose tissue (VAT) were studied in SIV-infected macaques and HIV-infected ART-controlled patients. To analyze the effect of Tat or Nef, we used human adipose stem cells (ASCs) issued from healthy donors, and analyzed adipogenesis and extracellular matrix component production using two dimensional (2D) and three-dimensional (3D) culture models.

METHODS

Adipocyte size and index of fibrosis were determined on Sirius red-stained adipose tissue samples. Proliferating and adipocyte 2D-differentiating or 3D-differentiating ASCs were treated chronically with Tat or Nef. mRNA, protein expression and secretion were examined by RT-PCR, western-blot and ELISA.

RESULTS

SCAT and VAT from SIV-infected macaques displayed small adipocytes, decreased adipogenesis and severe fibrosis with collagen deposition. SCAT and VAT from HIV-infected ART-controlled patients presented similar alterations. In vitro, Tat and/or Nef induced a profibrotic phenotype in undifferentiated ASCs and altered adipogenesis and collagen production in adipocyte-differentiating ASCs.

CONCLUSION

We demonstrate here a specific role for HIV/SIV infection per se on adipose tissue fibrosis and adipogenesis, probably through the release of viral proteins, which could be involved in adipose tissue dysfunction contributing to cardiometabolic alterations of HIV-infected individuals.

High-Density Lipoprotein Processing and Premature Cardiovascular Disease

High plasma concentrations of low-density lipoprotein-cholesterol (LDL-C) are a well-accepted risk factor for cardiovascular disease (CVD), and the statin class of hypolipidemic drugs has emerged as an effective means of lowering LDL-C and reducing CVD risk. In contrast, the role of plasma high-density lipoproteins (HDL) in protection against atherosclerotic vascular disease is the subject of considerable controversy. Although the inverse correlation between plasma HDL-C and CVD is widely acknowledged, reduction of CVD risk by interventions that increase HDL-C have not been uniformly successful. Several studies of large populations have shown that the first step in reverse cholesterol transport (RCT), the transfer of cholesterol from the subendothelial space of the arterial wall via the plasma compartment to the liver for disposal, is impaired in patients with CVD. Here we review HDL function, the mechanisms by which HDL supports RCT, and the role of RCT in preventing CVD.

A Prospective, Multicentre, Open-Label Single-Arm Exploratory Study to Evaluate Efficacy and Safety of Saroglitazar on Hypertriglyceridemia in HIV Associated Lipodystrophy

Objective

This study was designed to explore the efficacy and safety of saroglitazar 4 mg on hypertriglyceridemia in patients with HIV associated lipodystrophy.

Methods

During this 12-week prospective, multi-centric, open-label, single arm exploratory study, 50 patients were enrolled to receive saroglitazar 4 mg orally once daily in the morning before breakfast. The primary efficacy endpoint was the percent change in triglyceride (TG) levels from baseline to Week 6 and Week 12. The secondary efficacy endpoints were assessment of low-density-lipoprotein (LDL), very-low-density-lipoprotein (VLDL), high-density-lipoprotein (HDL), non-HDL cholesterol, total cholesterol, apo-lipoprotein (Apo) A1, Apo B, and C-peptide and fasting insulin for HOMA beta and HOMA IR. Safety assessment was performed during the study.

Results

Saroglitazar 4 mg significantly decreased the serum TG levels from baseline at Week 6 (percent change: -40.98; 95% CI: -50.82, -31.15) and Week 12 (percent change -45.11; 95% CI: -52.37, -37.86). Reduction in VLDL cholesterol (percent change: -46.33; 95% CI: -52.89, -39.76) and total cholesterol (percent change: 7.37; 95% CI: 1.96, 12.78) was observed at week 12 from baseline. Saroglitazar increased HDL cholesterol (percent change: 34.56, 95% CI: 22.22, 46.90), Apo A1 (percent change: 33.16; 95% CI: 18.69, 47.63) and Apo B (percent change: 10.55, 95% CI: 2.86, 18.25) levels at week 12 from baseline. Saroglitazar treatment led to increase in the C-peptide (percent change: 59.42, 95% CI: 48.78, 70.06), fasting insulin levels (percent change: 47.10; 95% CI: 38.63, 55.57), HOMA of beta cell function for C-peptide (percent change: 71.67; 95% CI: 39.09, 104.26) and HOMA of insulin resistance for C-peptide (percent change: 58.29, 95% CI: 46.74, 69.83) at week 12 from baseline. Saroglitazar treatment was safe and well tolerated in this study.

Conclusion

Overall, the observed changes in lipid profile after 12 weeks of saroglitazar treatment were in the direction of improvement in patients with HIV associated lipodystrophy.

Trial Registration

Clinical Trial Registry of India Phase II/CTRI/2010/091/000107

Viral mechanisms of adipose dysfunction: lessons from HIV-1 Vpr

HIV-associated lipodystrophy is a heterogeneous, evolving condition associated with fundamental defects in adipose tissue differentiation, turnover and function. Although many antiretroviral drugs can affect adipose tissues adversely, clinical evidence suggests that factors associated with the virus per se could play a role. We have focused on the possibility that an HIV accessory protein, viral protein R (Vpr) could dysregulate metabolically critical transcription factors to cause the adipose dysfunction. In a recent study published in Science Translational Medicine, we utilized 2 animal models to show that Vpr, produced in tissues that sequester HIV after antiretroviral therapy, can act in a paracrine or endocrine fashion to disrupt adipocyte differentiation and function by inhibiting PPARγ target gene expression and activating glucocorticoid target gene expression. The phenotypic consequences included many features typical of the human syndrome, including accelerated lipolysis, increased macrophage infiltration in adipose tissue, diminished size of white adipose depots and hepatic steatosis. In this commentary, we summarize the background, results, and implications of these studies, and raise important questions for future investigation. More broadly, these studies suggest that chronic viral infections may be a causative factor in the pathogenesis of some forms of lipid metabolic disease, insulin resistance, and diabetes.

Pathogenesis and significance of hepatitis C virus steatosis: An update on survival strategy of a successful pathogen

Hepatitis C virus (HCV) is a successful pathogen on the grounds that it exploits its host’s metabolism to build up viral particles; moreover it favours its own survival by inducing chronic disease and the development of specific anatomic changes in the infected organ. Steatosis, therefore, is associated with HCV infection by necessity rather than by chance alone. Approximately 6% of HCV patients have steatohepatitis. Interestingly, HCV steatosis occurs in the setting of multiple metabolic abnormalities (hyperuricemia, reversible hypocholesterolemia, insulin resistance, arterial hypertension and expansion of visceral adipose tissue) collectively referred to as “hepatitis C-associated dysmetabolic syndrome” (HCADS). General, nonalcoholic fatty liver disease (NAFLD)-like, mechanisms of steatogenesis (including increased availability of lipogenic substrates and de novo lipogenesis; decreased oxidation of fatty substrates and export of fatty substrates) are shared by all HCV genotypes. However, genotype 3 seemingly amplifies such steatogenic molecular mechanisms reported to occur in NAFLD via more profound changes in microsomal triglyceride transfer protein; peroxisome proliferator-activated receptor alpha; sterol regulatory element-binding proteins and phosphatase and tensin homologue. HCV steatosis has a remarkable clinical impact in as much as it is an acknowledged risk factor for accelerated fibrogenesis; for impaired treatment response to interferon and ribavirin; and development of hepatocellular carcinoma. Recent data, moreover, suggest that HCV-steatosis contributes to premature atherogenesis via both direct and indirect mechanisms. In conclusion, HCV steatosis fulfills all expected requirements necessary to perpetuate the HCV life cycle. A better understanding of the physiology of HCADS will likely result in a more successful handling of disease with improved antiviral success rates.

Lipid profile of HIV-infected patients in relation to antiretroviral therapy: a review

This study reviewed the lipid profile of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) patients in relation to use of antiretroviral therapy (ART), and its different classes of drugs. A total of 190 articles published in peer-reviewed journals were retrieved from PubMed and LILACS databases; 88 of them met the selection criteria and were included in the review. Patients with HIV/AIDS without ART presented an increase of triglycerides and decreases of total cholesterol, low density lipoprotein (LDL-c), and high density lipoprotein (HDL-c) levels. Distinct ART regimens appear to promote different alterations in lipid metabolism. Protease inhibitors, particularly indinavir and lopinavir, were commonly associated with hypercholesterolemia, high LDL-c, low HDL-c, and hypertriglyceridemia. The protease inhibitor atazanavir is apparently associated with a more advantageous lipid profile. Some nucleoside reverse-transcriptase inhibitors (didanosine, stavudine, and zidovudine) induced lipoatrophy and hypertriglyceridemia, whereas abacavir increased the risk of cardiovascular diseases even in the absence of apparent lipid disorders, and tenofovir resulted in lower levels of cholesterol and triglycerides. Although non-nucleoside reverse-transcriptase inhibitors predisposed to hypertriglyceridemia and hypercholesterolemia, nevirapine was particularly associated with high HDL-c levels, a protective factor against cardiovascular diseases. Therefore, the infection itself, different classes of drugs, and some drugs from the same class of ART appear to exert distinct alterations in lipid metabolism.

Patients with immunodeficiency

Patients presenting in an immunocompromised state merit special consideration when being evaluated for fitness to undergo surgery. A variety of immunodeficient conditions and their respective therapies, including human immunodeficiency virus, cancer, and transplantation, exert numerous systemic effects that may lead to multiorgan dysfunction. Understanding the potential impact of these disease manifestations, and their proper evaluation, is essential in achieving optimal perioperative outcomes for these patients.

Altered relationship of plasma triglycerides to HDL cholesterol in patients with HIV/HAART-associated dyslipidemia: further evidence for a unique form of metabolic syndrome in HIV patients

INTRODUCTION

Plasma triglycerides (TG) and HDL-C are inversely related in Metabolic Syndrome (MetS), due to exchange of VLDL-TG for HDL-cholesteryl esters catalyzed by cholesteryl ester transfer protein (CETP). We investigated the relationship of TG to HDL-C in highly-active antiretroviral drug (HAART)-treated HIV patients.

METHODS

Fasting plasma TG and HDL-C levels were compared in 179 hypertriglyceridemic HIV/HAART patients and 71 HIV-negative persons (31 normotriglyceridemic (NL) and 40 hypertriglyceridemic due to type IV hyperlipidemia (HTG)). CETP mass and activity were compared in 19 NL and 87 HIV/HAART subjects.

RESULTS

Among the three groups, a plot of HDL-C vs. TG gave similar slopes but significantly different y-intercepts (9.24±0.45, 8.16±0.54, 6.70±0.65, sqrt(HDL-C) for NL, HIV and HTG respectively; P<0.001); this difference persisted after adjusting HDL-C for TG, age, BMI, gender, glucose, CD4 count, viral load and HAART strata (7.18±0.20, 6.20±0.05 and 4.55±0.15 sqrt(HDL-C) for NL, HIV and HTG, respectively, P<0.001). CETP activity was not different between NL and HIV, but CETP mass was significantly higher in HIV (1.47±0.53 compared to 0.93±0.27μg/mL, P<0.0001), hence CETP specific activity was lower in HIV (22.67±13.46 compared to 28.46±8.24nmol/μg/h, P=0.001).

CONCLUSIONS

Dyslipidemic HIV/HAART patients have a distinctive HDL-C plasma concentration adjusted for TG. The weak inverse relationship between HDL-C and TG is not explained by altered total CETP activity; it could result from a non-CETP-dependent mechanism or a decrease in CETP function due to inhibitors of CETP activity in HIV patients' plasma.

Pathophysiology of the HIV-Associated Lipodystrophy Syndrome

The widespread use of highly active antiretroviral therapy (HAART) has radically transformed the prognosis of HIV-infected patients in the developed countries. Unfortunately, a serious metabolic syndrome combining peripheral lipoatrohy, central adiposity, insulin resistance, and dyslipidemia has arisen in these individuals. The etiology of this heterogeneous syndrome named lipodystrophy syndrome (LDS) is multifactorial, but adipose tissue is very likely a key factor that contributes to several clinical or metabolic aspects of the syndrome. In peripheral adipose tissue, HAART may act on both preadipocytes and adipocytes to induce fat loss. Several components of the HAART regimen can inhibit preadipocyte differentiation, in particular through alterations in the expression and/or function of the transcription factor sterol responsive element binding protein-1c. In superficial mature adipocytes, HAART promotes insulin resistance and apoptosis. Insulin resistance of peripheral fat cells could be the consequence of increased lipolysis and adipocytokine dysregulation. In turn, the increased free fatty acid disposal and the disturbances in adipocytokine production may induce skeletal muscle and liver insulin resistance, dyslipidemia, and a fat redistribution toward deep depots, causing visceral lipohypertrophy. The metabolic profile observed in LDS is reminiscent of that observed in metabolic syndrome, raising potential implications for cardiovascular risk in these patients. The pathophysiological mechanisms at the basis of this syndrome represent a rational basis for the treatment or prevention of the metabolic complications.

Hepatic steatosis in HIV-HCV coinfected patients receiving antiretroviral therapy is associated with HCV-related factors but not antiretrovirals

Background

In HIV and hepatitis C virus (HCV) coinfected patients, the role of antiretroviral therapy (ART) on hepatic steatosis (HS) remains controversial.

Methods

HIV/HCV coinfected patients receiving ART and previously untreated for HCV who underwent a liver biopsy were included. Cumulative duration of exposure to each antiretroviral was recorded up to liver biopsy date. Logistic regression analyses evaluated factors associated with steatosis and its severity.

Results

184 patients were included: median age 41years, 84% male, 89% Caucasian, 61% with a past history of intravenous drug use. HCV genotypes were 1 (55%), 2 (6%), 3 (26%), and 4 (13%). Median HCV-RNA was 6.18 log₁₀ IU/ml. HIV-RNA was undetectable (<400 copies/ml) in 67% of patients. Median CD4 count was 321/mm³. All patients had been exposed to nucleoside reverse transcriptase inhibitors (median cumulative exposure 56months); 126 received protease inhibitors (23months), and 79 non-nucleoside reverse transcriptase inhibitors (16months). HS was observed in 102 patients (55%): 41% grade 1; 5% grade 2, and 9% grade 3. In multivariate analysis, HCV genotype 3 and HCV viral load were moderately associated with mild steatosis but strongly with grade 2-3 steatosis. After adjustment for the period of biopsy, no association was detected between HS and exposure to any antiretroviral class or drug, or duration of ART globally or comparing genotype 3 to others.

Conclusions

Among our ART-treated HIV-HCV cohort predominantly infected with genotype 1, 55% of patients had HS which was associated with HCV-related factors, but not ART class or duration of exposure.

Dysregulation of glucose metabolism in HIV patients: epidemiology, mechanisms, and management

HIV-infected patients on highly active antiretroviral therapy (HAART) have increased prevalence of a number of chronic metabolic disorders of multifactorial but unclear etiology. These include disorders of lipid metabolism with or without lipodystrophy, insulin resistance, and an increased prevalence of impaired glucose tolerance, diabetes mellitus, and cardiometabolic syndrome. While much attention has been focused on the lipid and cardiovascular disorders, few investigations have attempted to characterize the prevalence, incidence, etiology, mechanisms, and management of glycemic disorders in HIV patients. In this review, we have focused specifically on a comprehensive assessment of dysglycemia in the context of HIV infection and HAART.

Growth hormone and tesamorelin in the management of HIV-associated lipodystrophy

HIV-infected patients on highly active antiretroviral therapy (HAART) develop a complex of body composition changes known, including peripheral fat loss (lipoatrophy) and central fat accumulation (lipohypertrophy). These changes may cause significant patient distress, which could in turn interfere with adherence to antiretroviral therapy. Treatment options - including antiretroviral switch, insulin sensitizers, and surgical approaches - have been associated with limited success and potential complications. The observation that low growth hormone levels are associated with central fat accumulation among HIV patients has led to the development of tesamorelin (a growth hormone releasing hormone analog) for the management of central fat accumulation. Randomized controlled trials have shown that administration of tesamorelin is safe and effective in reducing central fat accumulation among HIV-infected patients. This effect is transient, however, and its association with improved cardiovascular risk remains unclear.

Circulating Nef induces dyslipidemia in simian immunodeficiency virus-infected macaques by suppressing cholesterol efflux

Human immunodeficiency virus (HIV) infection and subsequent antiretroviral therapy have been associated with an increased incidence of dyslipidemia and cardiovascular disease and has been shown to suppress cholesterol efflux from virus-infected macrophages by inducing Nef-dependent down-regulation of adenosine triphosphate-binding cassette transporter A1 (ABCA1). Here, the simian immunodeficiency virus (SIV)-infected macaque model was used to examine the consequences and mechanisms involved. SIV infection drove a significant remodeling of high-density lipoprotein profiles, suggesting that systemic inhibition of the ABCA1-dependent reverse cholesterol transport pathway occurred. The ABCA1 cholesterol transporter was significantly down-regulated in the livers of the SIV-infected macaques, and the viral protein Nef could be detected in the livers as well as in the plasma of infected animals. Extracellular myristoylated HIV Nef inhibited cholesterol efflux from macrophages and hepatocytes. Moreover, serum samples from SIV-infected macaques also suppressed cholesterol efflux in a Nef-dependent fashion. These results indicate that SIV infection is a significant contributor to primary dyslipidemia, likely through the ability of Nef to suppress ABCA1-dependent reverse cholesterol transport.

Antiretroviral therapy with or without protease inhibitors impairs postprandial TAG hydrolysis in HIV-infected men

Mechanisms underlying the lipodystrophy syndrome associated with antiretroviral therapy (ART) for HIV infection are not completely understood. We investigated the effect of ART on blood lipid concentrations in the fasting state and after consumption of a meal containing [1-13C]palmitic acid in HIV-positive men receiving nucleoside reverse transcriptase inhibitors (NRTI,n7), NRTI combined with protease inhibitors (PI; NRTIPI,n6), in HIV-positive but therapy-naïve men (noART,n5) and in HIV-seronegative men (controls,n6). HIV-positive subjects had higher fasting TAG concentrations and resting energy expenditure than controls. Subjects receiving NRTIPI therapy had higher fasting NEFA concentrations than the other groups. There were no significant differences in postprandial lipid metabolism between noART subjects and controls. NRTI therapy impaired hydrolysis of meal-derived TAG, most evidently when combined with PI (the NRTIPI group). Accumulation of13C-label in the NEFA fraction was not different between groups. In the NRTIPI group, fasting and postprandial NEFA concentrations were significantly higher than other groups. Postprandial glucose and insulin responses in HIV-positive subjects did not differ from controls. These findings suggest that ART dyslipidaemia is associated with impaired postprandial TAG clearance, which is exacerbated by NRTIPI therapy. If dyslipidaemia is to be minimised in ART, the specific adverse effects of particular combinations during the fed state should be considered.

Relationship of postprandial nonesterified fatty acids, adipokines, and insulin across gender in human immunodeficiency virus-positive patients undergoing highly active antiretroviral therapy

BACKGROUND

Metabolic derangements are common in human immunodeficiency virus (HIV)-positive subjects undergoing antiretroviral therapy, but little is known about postprandial conditions.

METHODS

We investigated the relationship between leptin, adiponectin, nonesterified fatty acids (NEFA), and insulin in response to a day-long meal pattern and evaluated gender differences in HIV-positive men (n = 12) and women (n = 13) undergoing highly active antiretroviral therapy (HAART).

RESULTS

For both men and women, a significant decrease in postprandial NEFA levels was observed following breakfast (0.53 vs. 0.22 mmol/L, P < 0.001, baseline and at 3 hours, respectively), whereas day-long postprandial leptin and adiponectin levels showed small nonsignificant oscillations. In contrast to NEFA and adiponectin, postprandial leptin levels were significantly higher among women compared to men (P < 0.05). Postprandial NEFA levels correlated positively with fasting insulin levels (r(2) = 0.25, P = 0.016), and the postbreakfast decrease in NEFA levels correlated significantly with the postbreakfast increase in insulin levels (r(2) = 0.17, P = 0.038). No significant association between postprandial adipokines and insulin was observed.

CONCLUSIONS

In HAART-treated, HIV-infected men and women, levels of NEFA, but not adipokines, showed significant postprandial variation. Furthermore, food intake resulted in significant NEFA suppression in proportion to the food-stimulated insulin increase.

Body-fat abnormalities in patients with HIV: progress and challenges

The introduction of newer antiretroviral drugs has provided greater levels of HIV suppression with fewer of the metabolic effects, lipoatrophy, and body habitus changes associated with earlier therapies. Previously classified under the collective term, lipodystrophy, lipoatrophy and body-fat changes are now known to occur independently in some HIV-infected patients, depending on the type and duration of antiretroviral therapy and a myriad of factors including HIV infection alone that contribute significantly to these changes. This article reviews the current scientific literature and recent clinical trial results that distinguish lipoatrophy or dyslipidemia pathophysiologically from body-fat changes seen as central and peripheral lipohypertrophy and fat redistribution, as well as the nature and extent of changes associated with HIV infection alone and newer antiretroviral therapies. This information may assist physicians in identifying individual risk factors and choosing the type of antiretroviral therapy that may minimize these changes without loss of virologic suppression.

Investigation and management of hypertriglyceridaemia

While the precise definition of hypertriglyceridaemia remains contentious, the condition is becoming more common in western populations as the prevalence of obesity and diabetes mellitus rise. Although there is strong epidemiological evidence that hypertriglyceridaemia is an independent risk factor for cardiovascular disease, it is has been difficult to demonstrate this by drug intervention studies, as drugs that reduce triglycerides also raise high density lipoprotein cholesterol. Precise target values have also been difficult to agree, although several of the new guidelines for coronary risk management now include triglycerides. The causes of hypertriglyceridaemia are numerous. The more severe forms have a genetic basis, and may lead to an increased risk of pancreatitis. Several types of hypertriglyceridaemia are familial and are associated with increased cardiovascular risk. Secondary causes of hypertriglyceridaemia are also numerous and it is important to exclude these before starting treatment with specific triglyceride-lowering agents. Lifestyle management is also very effective and includes weight reduction, restricted alcohol and fat intake and exercise.

Feasibility of assessing autonomic dysregulation at a distance: the case of the HIV-positive patient

Alterations in lipid metabolism are a possible consequence of highly active antiretroviral therapies (HAART) for human immunodeficiency virus (HIV)-positive patients with consequent increase of cardiovascular risk. In this context we hypothesized that both acquired immunodeficiency syndrome (AIDS) and HAART might be associated to alterations in autonomic cardiovascular regulation. In this preliminary investigation we enrolled a total of 66 men, subdivided in two groups, 33 HIV-positive patients, and 33 healthy controls, and we tested the hypothesis that heart rate variability (HRV) of HIV positive patients can be assessed with a transtelephonic approach from the HIV clinic: 100% of the total of electrocardiograms (ECG) recordings that were sent from the distant site were successfully received and analyzed. Evaluation of the signal was subsequently performed in the centralized laboratory, and consisted in extracting the RR interval variability (RRV) series and afterward subjecting it to autoregressive spectral analysis. This study shows the feasibility of obtaining, from personnel without specific training, adequate RR variability data for further spectral analysis form a distant specialized autonomic laboratory. This feature is of critical importance in the context of possible large-scale application of this simple telemedicine approach.

HIV-positive patients with nonalcoholic fatty liver disease have a lower body mass index and are more physically active than HIV-negative patients

OBJECTIVE

To determine whether the clinical and metabolic features associated with nonalcoholic fatty liver disease (NAFLD) are similar between HIV-positive and HIV-negative male subjects.

METHODS

Twenty-six HIV-positive and 25 HIV-negative subjects with liver biopsy-proven NAFLD were compared for liver histology (extent of steatosis, steatosis grading, and fibrosis staging), blood biochemistry (glucose, insulin, C-peptide, hemoglobin A1c, and lipid profile), insulin resistance (IR) using a homeostasis model assessment, anthropometry (body mass index [BMI], waist circumference, and arm muscle area), dietary intake, and physical activity.

RESULTS

The 2 groups were similar for age, liver histology, and IR. HIV-positive patients had a lower BMI (26.3 +/- 0.5 vs. 30.2 +/- 1.0 kg/m; P = 0.001) and lower percentage of fat mass (19.4 +/- 0.9 vs. 22.7 +/- 1.2; P = 0.026) when compared with HIV-negative patients. Although caloric intake was similar between groups, HIV-positive patients had a higher physical activity level (8.3 +/- 1.6 vs. 4.1 +/- 0.8 units of exercise per day; P = 0.029). Blood triglycerides were significantly higher (3.14 +/- 0.39 vs. 1.86 +/- 0.20 mmol/L; P = 0.006) in HIV-positive patients.

CONCLUSION

Although NAFLD was similar between the 2 groups, HIV-positive patients had a lower BMI and were more physically active compared with HIV-negative patients. This may suggest that in HIV, NAFLD is associated with factors other than those related to body fatness, such as HIV infection and treatment.

HIV-associated adipose redistribution syndrome (HARS): definition, epidemiology and clinical impact

A segment of the HIV infected population develops abnormal and excessive accumulation of adipose tissue in the trunk, including accumulation of visceral (deep abdominal) adipose tissue. This condition, known as HIV-related adipose redistribution syndrome (HARS), may also be accompanied by fat accumulation in the upper back/neck (dorsocervical region) and/or depletion of subcutaneous adipose tissue from the abdomen, face, limbs, or buttocks. HARS is estimated to occur in up to 32% of patients and is associated with health risks similar to those of metabolic syndrome. Techniques to detect and measure HARS include physician and patient assessments and radiologic or anthropometric methods.

HIV-associated adipose redistribution syndrome (HARS): etiology and pathophysiological mechanisms

Human immunodeficiency virus (HIV)-associated adipose redistribution syndrome (HARS) is a fat accumulation disorder characterized by increases in visceral adipose tissue. Patients with HARS may also present with excess truncal fat and accumulation of dorsocervical fat ("buffalo hump"). The pathophysiology of HARS appears multifactorial and is not fully understood at present. Key pathophysiological influences include adipocyte dysfunction and an excessive free fatty acid release by adipocyte lipolysis. The contributory roles of free fatty acids, cytokines, hormones including cortisol, insulin and the growth hormone-adipocyte axis are significant. Other potential humoral, paracrine, endocrine, and neural influences are also discussed.

Metabolic effects of protease inhibitor-sparing antiretroviral regimens given as initial treatment of HIV-1 Infection (AIDS Clinical Trials Group Study A5095)

OBJECTIVE

To assess metabolic changes after initiation of protease inhibitor (PI)-sparing regimens in antiretroviral-naive patients.

METHODS

Metabolic changes were analyzed within the triple-nucleoside (zidovudine [ZDV]/lamivudine [3TC]/abacavir [ABC])-containing, 3-drug efavirenz (EFV) [ZDV/3TC + EFV]-containing, and 4-drug EFV [ZDV/3TC/ABC + EFV]-containing arms of the AIDS Clinical Trials Group multicenter trial A5095. Metabolic values were compared with published US general population norms.

RESULTS

From week 0 to week 24, all arms exhibited similar mild median increases in glucose and decreases in insulin sensitivity, whereas changes in lipids were greater in the ZDV/3TC + EFV and ZDV/3TC/ABC + EFV arms than in the ZDV/3TC/ABC arm: triglyceride (TG; 7, 18, and -1 mg/dL, respectively), total cholesterol (TC; 23, 28, and 5 mg/dL, respectively), low-density lipoprotein cholesterol (LDL-C; 9, 14, and 1 mg/dL, respectively), and high-density lipoprotein cholesterol (HDL-C; 10, 10, and 5 mg/dL, respectively). Adjusted mean study lipid values of all study participants at week 0 and week 96 compared with those of the National Health and Nutrition Examination Survey (NHANES) 1999 through 2002 values were: TG (148, 187, and 123 mg/dL, respectively), TC (164, 195, and 203 mg/dL, respectively), HDL-C (35, 47, and 51 mg/dL, respectively), and LDL-C (101, 117, and 123 mg/dL, respectively) (P < or = 0.005 for each value vs. NHANES values).

CONCLUSIONS

Similar mild increases in glucose and decreases in insulin sensitivity were observed in all regimens, whereas lipids were modestly higher in the EFV-containing arms. Compared with general population norms, the metabolic dysfunctions of concern after these PI-sparing therapies were increasingly abnormal TC and lower (but improved relative to baseline) HDL-C levels.

Reduction in triglyceride level with N-3 polyunsaturated fatty acids in HIV-infected patients taking potent antiretroviral therapy: a randomized prospective study

To assess the evolution of triglyceride (TG) levels in HIV-infected patients receiving stable potent antiretroviral therapy treated with N-3 polyunsaturated fatty acids (PUFAs), a prospective double-blind randomized design for a reliable assessment of TG evolution was performed. One hundred twenty-two patients with TG levels >2 g/L and < or =10 g/L after a 4-week diet (baseline TG: 4.5 +/- 1.9 g/L) were randomized for 8 weeks to N-3 PUFAs (2 capsules containing 1 g of fish oil 3 times daily, n = 60), or placebo (1 g of paraffin oil capsules, n = 62). An 8-week open-label phase of N-3 PUFAs followed. Evaluation criteria were TG percent change at week 8, percentage of responders (normalization or > or =20% TG decrease), and safety issues. Ten patients with baseline TG levels >10 g/L were not randomized and received N-3 PUFAs as open treatment. The difference (PUFA - placebo) in TG percent change at week 8 was -24.6% (range: -40.9% to -8.4%; P = 0.0033), the median was -25.5% in the PUFA group versus 1% in the placebo group, and mean TG levels at week 8 were 3.4 +/- 1.8 g/L and 4.8 +/- 3.1 g/L, respectively. TG levels were normalized in 22.4% (PUFA) versus 6.5% (placebo) of patients (P = 0.013) with a > or =20% reduction in 58.6% (PUFA) versus 33.9% (placebo) of patients (P = 0.007). Under the open-label phase of N-3 PUFAs, the decrease in TG levels was sustained at week 16 for patients in the PUFA group (mean TG: 3.4 +/- 1.7 g/L), whereas a 21.2% decrease in TG levels occurred for patients in the placebo group (mean TG: 3.3 +/- 1.4 g/L). No significant differences were observed between groups in the occurrence of adverse events. The median TG change at week 8 was -43.6% (range: Q1-Q3; 95% CI: -66.5% to -4.6%) for patients with baseline TG levels >10 g/L. The difference in mean total cholesterol between groups (PUFA - placebo) at week 8 was -8.5% (P = 0.0117). This study demonstrated the efficacy of PUFAs to lower elevated TG levels in treated HIV-infected hypertriglyceridemic patients. N-3 PUFAs have a good safety profile.

Lipid abnormalities in HIV/hepatitis C virus-coinfected patients

BACKGROUND

Among HIV-infected patients, hepatitis C virus (HCV) coinfection is associated with increased rates of lipodystrophy and insulin resistance. Its impact on HIV-associated dyslipidaemia is less clear.

METHODS

The lipid profiles of all HIV-infected patients and a subset of HCV-infected patients seen at the VA Medical Center in Dallas from January 2003 to March 2004 were analysed. Demographic data, HCV serostatus, and HIV treatment history were recorded. Lipid profiles of HIV/HCV-coinfected patients were compared with those of HIV-monoinfected and HCV-monoinfected patients.

RESULTS

A total of 359 HIV-infected patients, 91 (25.3%) of whom were HCV coinfected, and 112 HCV-infected patients were included in the analysis. Among the HIV-infected patients, HCV coinfection was associated with a reduced risk of hypercholesterolaemia [9.9% vs 24.8%; relative risk (RR)=0.333; 95% confidence interval (CI)=0.158-0.699; P<0.001] and hypertriglyceridaemia (48.4% vs 60.3%; RR=0.616; 95% CI=0.382-0.994; P=0.031). After controlling for duration of protease inhibitor (PI) therapy, race, alanine aminotransferase (ALT) concentration and platelet count, HCV remained an independent predictor of hypercholesterolaemia (RR=0.369; P=0.01) and any dyslipidaemia (RR=0.531; P=0.019). In addition, the rate of dyslipidaemias was lower among HCV-monoinfected than HIV/HCV-coinfected patients (29.5% vs 50.5; P=0.002). White race was also an independent predictor of dyslipidaemia (73.8% vs 50.7%; RR=2.32; 95% CI=1.44-3.76; P=0.001).

CONCLUSIONS

HCV coinfection independently predicted lower rates of dyslipidaemia among HIV-infected patients. An analysis of lipid kinetics among mono- and coinfected patients may elucidate the mechanisms of the apparent protective effect of HCV infection.

Effects of rosiglitazone and metformin on postprandial paraoxonase-1 and monocyte chemoattractant protein-1 in human immunodeficiency virus-infected patients with lipodystrophy

Highly active antiretroviral therapy in Human Immunodeficiency Virus (HIV) has been associated with lipodystrophy, insulin resistance and atherosclerosis. We investigated the effects of rosiglitazone or metformin on fasting and postprandial inflammatory and antioxidant variables in HIV-infected males with lipodystrophy. Thirty-one patients were randomly assigned to receive either rosiglitazone (4 mg twice daily) or metformin (1 g twice daily) for 26 weeks. At baseline and after treatment, standardized 10-h oral fat loading tests were performed. Before treatment, inflammatory variables remained unchanged but there was a postprandial decrease in high density lipoprotein (HDL)-cholesterol and paraoxonase (PON1) activity. Rosiglitazone and metformin reduced homeostasis model assessment index (HOMA) similarly (-34% and -37%, respectively, P<0.05 for each). Both treatments increased fasting and postprandial PON1 activity and decreased postprandial monocyte chemoattractant protein 1 (MCP-1) concentrations. However, plasma C-reactive protein (CRP) and Interleukin-6 (IL-6) concentration did not change throughout the study. To decrease insulin resistance results in a higher anti-oxidant and consequent lower pro-inflammatory action of HDL. This may confer protection against accelerated atherosclerosis in these 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.

[Metabolic alterations in HIV-associated lipodystrophy syndrome]

The introduction of highly active antiretroviral therapy (HAART) has reduced morbidity and mortality in patients infected with the human immunodeficiency virus (HIV). However, prolonged treatment with combination regimens can be difficult to sustain because of problems with adherence and toxic effects. Treatment with antiretroviral agents--protease inhibitors in particular--has uncovered a syndrome of abnormal fat redistribution, impaired glucose metabolism, insulin resistance and dyslipidemia, collectively termed lipodystrophy syndrome (SLHIV). Nowadays, no clinical guidelines are available for the prevention or treatment of SLHIV, and its cause have yet to be totally elucidated. This review emphasizes the clinical features and the data from previous studies about the SLHIV taking into account that a better understanding of this syndrome for HIV specialists, cardiologists and endocrinologists is fundamental for the disease control.

Tumor necrosis factor alpha is associated with insulin-mediated suppression of free fatty acids and net lipid oxidation in HIV-infected patients with lipodystrophy

Tumor necrosis factor alpha (TNF-alpha) stimulates lipolysis in man. We examined whether plasma TNF-alpha is associated with the degree by which insulin suppresses markers of lipolysis, for example, plasma free fatty acid (FFA) and net lipid oxidation (LIPOX) rate in HIV-infected patients with lipodystrophy (LIPO) and those without (controls). LIPOX was estimated by indirect calorimetry during fasting and steady state of a hyperinsulinemic euglycemic clamp in 36 (18 LIPO and 18 controls) normoglycemic HIV-infected men on highly active antiretroviral therapy. In LIPO, TNF-alpha correlated with clamp FFA (r = 0.67, P < .01), clamp LIPOX (r = 0.47, P < .05), incremental FFA (r = 0.69, P < .01), and incremental LIPOX (r = 0.64, P < .01), all of which, but not the clamp LIPOX correlation (r = 0.29, P > .05), remained significant after correction for insulin sensitivity. None of these correlations were significant in controls. In all patients, TNF-alpha correlated with clamp FFA (r = 0.61, P < .001), clamp LIPOX (r = 0.43, P < .01), and incremental FFA (r = 0.43, P < .01), with the 2 former correlations remaining significant after correction for insulin sensitivity. LIPOX and FFA (fasting and clamp values combined) correlated strongly and positively in both LIPO (R2 = 0.43, P < .001) and controls (R2 = 0.60, P < .0001). Fasting FFA and LIPOX did not differ between study groups; however, the insulin-mediated suppression of FFA and LIPOX was attenuated in LIPO (P's < .05). Our data indicate that higher TNF-alpha, independently of insulin sensitivity, is associated with attenuated insulin-mediated suppression of FFA and LIPOX in HIV-LIPO, suggesting in turn that TNF-alpha stimulates lipolysis in this syndrome. Furthermore, FFA may be a major determinant of LIPOX in HIV-infected patients on highly active antiretroviral therapy.

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.

Dyslipidaemia and cardiovascular risk in HIV infection

Cardiovascular disease is increasingly recognised as a consequence of human immunodeficiency virus (HIV) infection in the era of highly active antiretroviral therapy (HAART). Dyslipidaemia is also a feature of HIV infection itself and the antiretroviral drugs from the protease inhibitor classes. Increased rates of atherosclerotic disease and diabetes have been associated with lipodystrophy and now from one of the major causes of morbidity in HIV and acquired immunodeficiency syndrome (AIDS).This review, based on a multi-database keyword search, summarises the lipid changes observed in the course of HIV infection and its treatment, and puts them into the context of other risk factors for cardiac disease, and other causes of cardiovascular disease in HIV.

Cumulative exposure to nucleoside analogue reverse transcriptase inhibitors is associated with insulin resistance markers in the Multicenter AIDS Cohort Study

OBJECTIVE

To estimate insulin resistance and its relationship to antiretroviral therapy (ART) in a cohort of HIV-infected persons with comparison to HIV-seronegative controls.

DESIGN

Prospective cohort of 533 HIV-infected and 755 HIV-seronegative men in the Multicenter AIDS Cohort Study evaluated at 6-month intervals between 1999 and 2003.

METHODS

Recent ART exposure was assessed by type of treatment in the preceding 6 months [i.e., no ART, monotherapy, combination ART, or highly active antiretroviral therapy (HAART) with and without a protease inhibitor (PI)]. Cumulative exposure was determined for the three major ART classes and for individual medications within each class. Two endpoints, a modified QUICKI index, 100 x 1/[log10(glucose) + log10(insulin)] and fasting hyperinsulinemia (insulin > 15 microU/ml), were assessed. All statistical models were adjusted for age, body mass index, race, nadir CD4 cell count, hepatitis C serostatus and family history of diabetes mellitus.

RESULTS

Each of the HIV-infected groups had higher odds of hyperinsulinemia and lower mean QUICKI than the HIV-seronegative men. Each additional year of exposure to nucleoside analogue reverse transcriptase inhibitors (NRTI) was associated with increased odds of hyperinsulinemia [odds ratio (OR), 1.08; 95% confidence interval (CI), 1.02-1.13) and a lower QUICKI (-0.04; 95% CI, -0.07 to -0.01). Cumulative exposure to non-nucleoside analogue reverse transcriptase inhibitors or PI drugs was not associated with either insulin resistance marker. Of individual medications examined, stavudine was associated with the highest risk of hyperinsulinemia (OR, 1.2; 95% CI, 1.2-1.3).

CONCLUSIONS

Fasting surrogate markers suggest increased insulin resistance in HIV-infected men, which is related to cumulative NRTI exposure.

Postprandial response to a physiologic caloric load in HIV-positive patients receiving protease inhibitor-based or nonnucleoside reverse transcriptase inhibitor-based antiretroviral therapy

BACKGROUND

Features of the dyslipidemic pattern reported with the use of antiretroviral therapy predict enhanced postprandial lipemia, which is an emerging cardiovascular disease risk factor.

OBJECTIVE

We evaluated the postprandial response to a physiologic, meal-based challenge in HIV-positive subjects without hyperlipidemia.

DESIGN

We measured hourly lipid, lipoprotein, glucose, and insulin concentrations during a 13-h period in 25 nonwhite patients (13 women, 12 men): 13 receiving a protease inhibitor (PI)-based regimen (6 nelfinavir and 7 indinavir) and 12 receiving a nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimen (6 efavirenz and 6 nevirapine).

RESULTS

Mean fasting HDL-cholesterol concentrations were lower in HIV patients than in healthy subjects without HIV infection matched for age, sex, and ethnicity (z score: -0.81 +/- 0.9; P = 0.0001). Fasting triacylglycerol concentrations were not significantly different between HIV-infected patients and healthy subjects but were higher in PI-treated than in NNRTI-treated patients [median (interquartile range): 144 (110-191) and 89 (62-135) mg/dL; P = 0.007]. Average daylong triacylglycerol concentrations, but not incremental concentrations, were higher in the PI group than in the NNRTI group [205% (185-248%) and 125% (78-191%); P < 0.05]. For all HIV-positive patients, the fractional triacylglycerol increase was lower after breakfast than after lunch (20 +/- 18% and 42 +/- 40%, respectively; P < 0.04). Insulin concentrations were higher in PI-treated than in NNRTI-treated patients [22.6 (13.1-29.8) and 11.8 (7.1-19.1) microU/mL; P = 0.01] and increased in both groups in response to each meal, whereas glucose concentrations increased only after breakfast.

CONCLUSIONS

Despite baseline differences, incremental triacylglycerol and insulin responses to a physiologic caloric load among HIV-positive patients were not significantly affected by differences in the type of antiretroviral therapy.

Abnormalities in plasma fatty acid composition in human immunodeficiency virus-infected children treated with protease inhibitors

AIM

To study plasma fatty acid composition in human immunodeficiency virus-infected children treated with protease inhibitors and its relation with other components of the metabolic syndrome observed after this therapy.

DESIGN

Cross-sectional study from collected clinical database.

SUBJECTS

17 children with HIV infection treated with protease inhibitors. Nine patients received ritonavir (20-30 mg/kg/d) and the remaining eight received nelfinavir (60-90 mg/kg/d). Duration of protease inhibitors treatment was 711+/-208 d. As controls, we used 112 matched blood samples from apparently healthy children admitted for minor surgical procedures.

METHODS

Plasma fatty acids were determined using a Hewlett Packard GC 5890 gas chromatograph.

RESULTS

Plasma levels of cholesterol and triglycerides and insulin-like growth factor 1 (IGF-1) tended to be high in protease inhibitor-treated patients. Plasma content of omega6 long-chain polyunsaturated fatty acids and, in particular, of the highly unsaturated 22ratio4omega6 and 22ratio5omega6, was significantly increased. Also, infected children had increased Delta6 and Delta4 desaturase activities and decreased Delta5 desaturase activity. Significant correlations were present between plasma IGF-1 level and plasma triglycerides, plasminogen activator inhibitor-1 activity and Delta6 desaturase activity.

CONCLUSION

HIV-infected, protease inhibitor-treated children exhibit a metabolic syndrome which is associated with significant changes in plasma fatty acid composition. These changes are similar to those observed in situations of insulin resistance and are linked to variations in plasma IGF-1 concentration.

Fenofibrate is effective in treating hypertriglyceridemia associated with HIV lipodystrophy

OBJECTIVE

To determine the effectiveness of fenofibrate in treating hypertriglyceridemia associated with highly active antiretroviral therapy-associated HIV lipodystrophy syndrome (HLS).

METHODS

The authors recruited from their HIV metabolic clinic 55 adult patients with anthropomorphic changes consistent with HLS together with hypertriglyceridemia. The patients had no prior history of taking lipid-lowering medications and were free of liver and renal disease. They were on various highly active antiretroviral therapy regimens, and these regimens were not altered during the course of the study. Fenofibrate was started at 54 mg a day and the dose increased every 2 weeks to a maximum of 162 mg/day. Fasting lipid concentrations were measured at baseline and 6 months after the intervention.

RESULTS

At baseline, the fasting plasma concentrations of total cholesterol, triglyceride, and high-density lipoprotein (HDL) cholesterol were 259 +/- 11, 886 +/- 172, and 35.7 +/- 2.3 (mean +/- SEM) mg/dL, respectively. After 6 months of fenofibrate treatment, the fasting plasma concentrations were as follows: total cholesterol, 243 +/- 13; triglycerides, 552 +/- 104, and HDL cholesterol, 35.7 +/- 1.8 mg/dL. The decrease in fasting plasma triglyceride concentration was statistically significant (P < 0.05). Fenofibrate was well tolerated, and no subjects dropped out of the study.

CONCLUSION

Fenofibrate is an effective, well-tolerated treatment for hypertriglyceridemia associated with HLS.