Lipoprotein particle subclasses, cardiovascular disease and HIV infection

Microbial translocation and metabolic and body composition measures in treated and untreated HIV infection

Circulating levels of microbial products such as lipopolysaccharide (LPS) are increased in HIV infection. Microbial translocation promotes obesity, insulin resistance, and dyslipidemia in other settings. We examined data from 178 subjects: an Indiana University (IU) cross-sectional study [N=49 on antiretroviral therapy (ART), N=47 not on ART], and a 24 week prospective study of ART initiation ACTG 5152s (N=82). Pearson correlations were used to describe relationships of plasma LPS levels and soluble CD14 (sCD14), a marker of monocyte activation, with metabolic and body composition measures. HOMA-IR (a measure of insulin resistance) and LPS were correlated for the combined cohorts (r=0.19, p=0.02), particularly in the 5152s ART-naive cohort (r=0.41, p<0.01). Triglycerides were correlated with LPS in the combined cohort (r=0.32, p<0.01), and all subsets excluding the IU on ART subset. There were negative correlations between sCD14 and high-density lipoprotein (HDL) cholesterol in all subjects (r=-0.21, p<0.01), as well as the IU subset not on ART (r=-0.32, p=0.04). Large particle HDL as measured by NMR spectroscopy, but not HDL cholesterol, was negatively correlated with LPS (r=-0.18, p=0.02), particularly among the IU subset receiving ART (r=-0.33, p=0.03). In the combined cohorts, sCD14 was negatively correlated with lean mass as well as trunk and limb fat. There is a relationship between microbial translocation markers and metabolic effects, particularly lipoproteins. During prolonged ART, microbial translocation was associated with an adverse effect on large HDL and thus may contribute to the increased cardiovascular disease risk observed during chronic treatment of HIV.

HDL redox activity is increased in HIV-infected men in association with macrophage activation and non-calcified coronary atherosclerotic plaque

BACKGROUND

HIV is associated with atherosclerosis and low high-density lipoprotein (HDL). With inflammation, HDL becomes dysfunctional. We previously showed that proinflammatory HDL has high HDL redox activity (HRA). In this study, we compare HRA in HIV-infected versus non-HIV-infected subjects and relate HRA to indices of macrophage activation and cardiovascular disease risk.

METHODS

102 HIV-infected subjects and 41 matched non-HIV controls without clinical cardiovascular disease underwent coronary CT angiography (CTA) and testing for immune/inflammatory biomarkers. The effect of purified HDL from each study subject on the oxidation rate of dihydrorhodamine-123 (DOR) was normalized to the DOR of pooled HDL from healthy subjects. The normalized ratio DOR subject/DOR pooled was used as a measure of HRA, with higher HRA suggesting dysfunctional HDL.

RESULTS

HRA was higher in HIV-infected versus non-HIV subjects (1.4 ±0.01 versus 1.3 ±0.01, P=0.03). In multivariate modelling for HRA among all subjects, HIV status remained positively related to HRA (P=0.02), even after controlling for traditional cardiovascular risk factors, comorbid conditions and immune activation. Among HIV-infected subjects, HRA correlated inversely with HDL (rho=-0.32, P=0.002) and log adiponectin (r=-0.28, P=0.006), and correlated positively with log sCD163 (r=0.24, P=0.02) - a monocyte/macrophage activation marker - and with the percentage of non-calcified coronary atherosclerotic plaque (r=0.29, P=0.03). sCD163 remained significantly associated with HRA in multivariate modelling among HIV-infected subjects (P=0.03).

CONCLUSIONS

These data demonstrate increased HRA among HIV-infected subjects versus matched non-HIV subjects with comparable HDL levels. In HIV-infected subjects, HRA relates to macrophage activation and to non-calcified coronary atherosclerotic plaque, which may be rupture-prone. Further studies are needed in HIV-infected patients to elucidate the interplay between immune activation, HDL function and CVD risk.

CLINICAL TRIAL REGISTRATION NUMBER

NCT 00455793.

HIV infection and cardiovascular disease

AIMS

With the success of antiretroviral therapy (ART), non-human immunodeficiency virus (HIV)-related comorbidities like cardiovascular diseases (CVDs) are of increasing concern. We describe important recent research developments on the epidemiology of CVD in HIV infection, ART-related metabolic changes, and cardioprotective anti-inflammatory mechanisms, and summarize management strategies for CVD risk reduction.

METHODS AND RESULTS

We systematically identified and analysed systematic reviews and most cited literature published in the last 3 years and supplemented findings with selected evidence based on clinical expertise. Among HIV-infected individuals, the prevalence of CVD risk factors and the risk for CVD is higher compared with HIV negatives. Antiretroviral drugs may induce dyslipidaemia, reduce insulin sensitivity, and promote body fat redistribution that additionally contributes to CVD risk. Some antiretroviral drugs may increase risk for CVD events, but the absolute risk increase is moderate and has to be put into perspective with the massive HIV-related benefits. Sustained HIV suppression reduces systemic inflammatory markers and is associated with a moderate reduction in CVD events. Regular CVD risk assessment and counselling to stop smoking must be regularly done in all HIV-infected individuals. Statins are effective for the treatment of dyslipidaemia in HIV infection, but drug interactions with ART need to be considered.

CONCLUSION

Human immunodeficiency virus-infected individuals are at increased risk for CVD. Timely initiation of ART with consequent viral suppression is likely to reduce CVD events and to offset potential side effects from ART-induced metabolic changes. Reduction in smoking in HIV-infected individuals is a public health priority.

HIV/hepatitis C virus coinfection ameliorates the atherogenic lipoprotein abnormalities of HIV infection

BACKGROUND

Higher levels of small low-density lipoprotein (LDL) and lower levels of high-density lipoprotein (HDL) subclasses have been associated with increased risk of cardiovascular disease. The extent to which HIV infection and HIV/hepatitis C virus (HCV) coinfection are associated with abnormalities of lipoprotein subclasses is unknown.

METHODS

Lipoprotein subclasses were measured by nuclear magnetic resonance (NMR) spectroscopy in plasma samples from 569 HIV-infected and 5948 control participants in the Fat Redistribution and Metabolic Change in HIV Infection (FRAM), Coronary Artery Risk Development in Young Adults (CARDIA), and Multi-Ethnic Study of Atherosclerosis (MESA) studies. Multivariable regression was used to estimate the association of HIV and HIV/HCV coinfection with lipoprotein measures with adjustment for demographics, lifestyle factors, and waist-to-hip ratio.

RESULTS

Relative to controls, small LDL levels were higher in HIV-monoinfected persons (+381 nmol/l, P <0.0001), with no increase seen in HIV/HCV coinfection (-16.6 nmol/l). Levels of large LDL levels were lower (-196 nmol/l, P <0.0001) and small HDL were higher (+8.2 μmol/l, P < 0.0001) in HIV monoinfection with intermediate values seen in HIV/HCV coinfection. Large HDL levels were higher in HIV/HCV-coinfected persons relative to controls (+1.70 μmol/l, P <0.0001), whereas little difference was seen in HIV-monoinfected persons (+0.33, P = 0.075). Within HIV-infected participants, HCV was associated independently with lower levels of small LDL (-329 nmol/l, P <0.0001) and small HDL (-4.6 μmol/l, P <0.0001), even after adjusting for demographic and traditional cardiovascular risk factors.

CONCLUSION

HIV-monoinfected participants had worse levels of atherogenic LDL lipoprotein subclasses compared with controls. HIV/HCV coinfection attenuates these changes, perhaps by altering hepatic factors affecting lipoprotein production and/or metabolism. The effect of HIV/HCV coinfection on atherosclerosis and the clinical consequences of low small subclasses remain to be determined.

Residual immune dysregulation syndrome in treated HIV infection

Antiretroviral therapy has revolutionized the course of HIV infection, improving immune function and decreasing dramatically the mortality and morbidity due to the opportunistic complications of the disease. Nonetheless, even with sustained suppression of HIV replication, many HIV-infected persons experience a syndrome characterized by increased T cell activation and evidence of heightened inflammation and coagulation. This residual immune dysregulation syndrome or RIDS is more common in persons who fail to increase circulating CD4+ T cells to normal levels and in several epidemiologic studies it has been associated with increased morbidity and mortality. These morbid and fatal events are not the typical opportunistic infections and malignancies seen in the early AIDS era but rather comprise a spectrum of cardiovascular events, liver disease, metabolic disorders, kidney disease, bone disease, and a spectrum of malignant complications distinguishable from the opportunistic malignancies that characterized the earlier days of the AIDS epidemic. While immune activation, inflammation, and coagulopathy are characteristic of untreated HIV infection and improve with drug-induced control of HIV replication, the drivers of RIDS in treated HIV infection are incompletely understood. And while inflammation, immune activation, and coagulopathy are more common in treated persons who fail to restore circulating CD4+ T cells, it is not entirely clear how these two phenomena are linked.

HIV and the heart: the impact of antiretroviral therapy: a global perspective

From a global perspective, cardiovascular disease (CVD) in human immunodeficiency virus (HIV) may result from cardiac involvement upon presentation of opportunistic infections in the presence of advanced immunosuppression, be a consequence of HIV-induced immune activation or derive from antiretroviral therapy-associated dyslipidaemia and insulin resistance. Indeed, in developed countries with unlimited access to antiretroviral therapy CVD has become one of the major causes of death in HIV. Therefore, cardiovascular risk reduction and lifestyle modifications are essential and careful selection of the antiretroviral drugs according to underlying cardiovascular risk factors of great importance. In developing countries with delayed roll-out of antiretroviral therapy pericardial disease (often related to TB), HIV-associated cardiomyopathy, and HIV-associated pulmonary hypertension are the most common cardiac manifestations in HIV. In Africa, the epicentre of the HIV epidemic, dynamic socio-economic and lifestyle factors characteristic of epidemiological transition appear to have positioned the urban African community at the cross-roads between historically prevalent and 'new' forms of CVD, such as coronary artery disease. In this context, cardiovascular risk assessment of HIV-infected patients will become a critical element of care in developing countries similar to the developed world, and access to antiretroviral therapy with little or no impact on lipid and glucose metabolism of importance to reduce CVD in HIV.

The association of high-sensitivity c-reactive protein and other biomarkers with cardiovascular disease in patients treated for HIV: a nested case-control study

Background

Elevated high-sensitivity C-reactive protein (hsCRP) increases the risk of cardiovascular disease (CVD) in the general population, but its role as a predictive marker in HIV-positive patients remains unclear. Aim of the study was to evaluate whether hsCRP or other biomarkers are independent predictors of CVD risk in HIV-infected patients.

Methods

Retrospective, nested case–control study. HIV-positive men and women (35–69 years of age) receiving combination antiretroviral therapy (cART) were included. Cases (n = 35) had a major CVD event. Controls (n = 74) free from CVD events for at least 5 years from starting ART were matched on diabetes and smoking. HsCRP, D-dimer, P-selectin, interleukin-6 (IL-6), tissue plasminogen activator, plasminogen activator inhibitor-1 levels were measured.

Results

High hsCRP was associated with CVD risk, independently of traditional cardiovascular risk factors, HIV replication and the type of ART received at the time of sampling (adjusted odds ratio 8.00 [1.23-51.94] comparing >3.3 mg/L with <0.9 mg/L; P = 0.03). Higher IL-6 and P-selectin levels were also independently associated with increased CVD risk, although the association was weaker than for hsCRP. Higher total cholesterol and lower HDL cholesterol increased CVD risk, independent of hsCRP.

Conclusion

hsCRP may be a useful additional biomarker to predict CVD risk in HIV-infected patients receiving cART.

Cardiometabolic risk factors among HIV patients on antiretroviral therapy

BACKGROUND

HIV and combination antiretroviral therapy (cART) may increase cardiovascular disease (CVD) risk. We assessed the early effects of cART on CVD risk markers in a population with presumed low CVD risk.

METHODS

Adult patients (n=118) in Lusaka, Zambia were recruited at the time of initiation of cART for HIV/AIDS. Cardiometabolic risk factors were measured before and 90 days after starting cART. Participants were grouped according to cART regimens: Zidovudine + Lamivudine + Nevirapine (n=58); Stavudine + Lamivudine + Nevirapine (n=43); and 'other' (Zidovudine + Lamivudine + Efavirenz, Stavudine + Lamivudine + Efavirenz, Tenofovir + Emtricitabine + Efavirenz or Tenofovir + Emtricitabine + Nevirapine, n=17). ANOVA was used to test whether changes in cardiometabolic risk markers varied by cART regimen.

RESULTS

From baseline to 90 days after initiation of cART, the prevalence of low levels of high-density lipoprotein cholesterol (<1.04 mmol/L for men and <1.30 mmol/L for women) significantly decreased (78.8% vs. 34.8%, P<0.001) while elevated total cholesterol (TC ≥5.18 mmol/L, 5.1% vs. 11.9%, P=0.03) and the homeostasis model assessment of insulin resistance ≥3.0 (1.7% vs. 17.0%, P<0.001) significantly increased. The prevalence of TC:HDL-c ratio ≥5.0 significantly decreased (44.9% vs. 6.8%, P<0.001). These changes in cardiometabolic risk markers were independent of the cART regimen.

CONCLUSION

Our results suggest that short-term cART is associated with a cardioprotective lipid profile in Zambia and a tendency towards insulin resistance regardless of the cART regimen.

Incident hypertension in older women and men with or at risk for HIV infection

OBJECTIVES

Antiretroviral (ARV) therapy has prolonged the life expectancy of HIV-infected persons, increasing their risk of age-associated diseases, including atherosclerosis (AS). Decreased risk of AS has been associated with the prevention and control of hypertension (HTN). We conducted a cohort study of perimenopausal women and older men with or at risk of HIV infection to identify risk factors for incident HTN.

METHODS

Standardized interviews, physical examinations, and laboratory examinations were scheduled at 6-month intervals. Interview data included demographics, medical, family, sexual behaviour and drug use histories, and physical activity.

RESULTS

There were 330 women and 329 men eligible for inclusion in the study; 27% and 35% of participants developed HTN during a median follow-up period of 1080 and 1071 days, respectively. In gender-stratified analysis, adjusting for traditional HTN risk factors (age, race, body mass index, smoking, diabetes, family history of HTN, alcohol dependence, physical activity and high cholesterol), HIV infection was not associated with incident HTN in women [hazard ratio (HR) 1.31; 95% confidence interval (CI) 0.56, 3.06] or men (HR 1.67; 95% CI 0.75, 3.74). Among HIV-infected women, although exposure to ARVs was not significantly associated with incident HTN (HR 0.72; 95% CI 0.26, 1.99), CD4 T-cell count was positively associated with incident HTN (HR 1.15 per 100 cells/μL; 95% CI 1.03, 1.28). Among physically active HIV-infected men, exposure to ARVs was negatively associated with incident HTN (HR 0.15; 95% CI 0.03, 0.78).

CONCLUSIONS

HIV infection was not associated with incident HTN in older men or women. This study provides additional evidence supporting a causal relationship between immune function and incident HTN, which warrants further study.

Effect of darunavir on lipid profile in HIV-infected patients

Highly active antiretroviral therapy regimens, consisting of a ritonavir-boosted protease inhibitor (PI) and 2 nucleoside reverse transcriptase inhibitors, are established first-line regimens for HIV-infected patients. However, a common adverse effect in patients receiving PIs is dyslipidemia, characterized by increases in plasma levels of triglycerides, low-density lipoprotein cholesterol, and total cholesterol (TC). These lipid changes, as well as other well-described risk factors, may predispose patients to the development of cardiovascular disease, an important comorbidity, especially as the lifespan of HIV-infected patients has increased dramatically in recent years. Among PIs, ritonavir-boosted atazanavir (ATV/r) and, more recently, ritonavir-boosted darunavir (DRV/r) have demonstrated potent antiviral efficacy with more favorable lipid profiles than other PIs. This review provides an overview of the lipid effects of DRV/r. Studies with DRV/r in healthy volunteers and in both treatment-naïve and -experienced patients have demonstrated that changes in tri-glycerides and TC are comparable to those seen with ATV/r.

Metabonomic analysis of HIV-infected biofluids

Monitoring the progression of HIV infection to full-blown acquired immune deficiency syndrome (AIDS) and assessing responses to treatment will benefit greatly from the identification of novel biological markers especially since existing clinical indicators of disease are not infallible. Nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS) are powerful methodologies used in metabonomic analyses for an approximation of HIV-induced changes to the phenotype of an infected individual. Although early in its application to HIV/AIDS, (biofluid) metabonomics has already identified metabolic pathways influenced by both HIV and/or its treatment. To date, biofluid NMR and MS data show that the virus and highly active antiretroviral treatment (HAART) mainly influence carbohydrate and lipid metabolism, suggesting that infected individuals are susceptible to very specific metabolic complications. A number of well-defined biofluid metabonomic studies clearly distinguished HIV negative, positive and treatment experienced patient profiles from one another. While many of the virus or treatment affected metabolites have been identified, the metabonomics measurements were mostly qualitative. The identities of the molecules were not always validated neither were the statistical models used to distinguish between groups. Assigning particular metabolic changes to specific drug regimens using metabonomics also remains to be done. Studies exist where identified metabolites have been linked to various disease states suggesting great potential for the use of metabonomics in disease prognostics. This review therefore examines the field of metabonomics in the context of HIV/AIDS, comments on metabolites routinely detected as being affected by the pathogen or treatment, explains what existing data suggest and makes recommendations on future research.

LDL subclasses and lipoprotein-phospholipase A2 activity in suppressed HIV-infected patients switching to raltegravir: Spiral substudy

OBJECTIVE

To analyze the effect of switching the ritonavir-boosted protease inhibitor (PI/r) in a stable combined antiretroviral therapy (cART) regimen to raltegravir on low-density lipoprotein (LDL) particles, and lipoprotein-associated phospholipase A2 (Lp-PLA2).

DESIGN

Substudy of a multicenter randomized trial that compared the efficacy of switching a PI/r to raltegravir-based cART in stable HIV-infected patients.

METHODS

LDL size and phenotype (by gel-gradient electrophoresis), Lp-PLA2 (by 2-thio-PAF [Cayman]), proprotein convertase subtilisin/kexin type 9 (PCSK9) (by ELISA), and standard lipid parameters were measured at baseline and week 48.

RESULTS

Eighty-one (PI/r n = 41 and raltegravir n = 40) patients were evaluated. No differences in baseline demographic and metabolic variables between arms were found except in apolipoprotein (Apo) B (p = 0.042). At week 48, total cholesterol (TC) (p < 0.001), LDL-c (p = 0.023), non-high density lipoprotein cholesterol non-high-density lipoprotein cholesterol (non-HDL-c) (p < 0.001), TC/HDL (p = 0.026), triglyceride (p < 0.001), Apo B (p < 0.001), Apo A-I (p = 0.004) and Lp (a) (p = 0.005) decreased in raltegravir arm compared to PI/r arm. At week 48, a shift from LDL phenotype B to the less atherogenic phenotype A was observed only in raltegravir arm (p < 0.001). LDL size increased (PI/r 2.1 nm, p = 0.019; raltegravir 3.8 nm, p = 0.001) and cholesterol content in small and dense LDL subfractions (LDL 4,5,6) decreased (PI/r p = 0.007, raltegravir p = 0.006) at week 48 in both arms. Total Lp-PLA2 activity (PI/r p = 0.037 and raltegravir p = 0.051) and PCSK9 plasma concentration decreased in both arms (PI/r p = 0.034 and raltegravir p < 0.001).

CONCLUSIONS

Switching a PI/r to a raltegravir-based cART in virologically suppressed HIV-infected patients was associated with an overall improvement in lipid profile, including a shift to a less atherogenic LDL phenotype.

High-density lipoprotein cholesterol and particle concentrations, carotid atherosclerosis, and coronary events: MESA (multi-ethnic study of atherosclerosis)

OBJECTIVES

The purpose of this study was to evaluate independent associations of high-density lipoprotein cholesterol (HDL-C) and particle (HDL-P) concentrations with carotid intima-media thickness (cIMT) and incident coronary heart disease (CHD).

BACKGROUND

HDL-C is inversely related to CHD, and also to triglycerides, low-density lipoprotein particles (LDL-P), and related metabolic risk. HDL-P associations with CHD may be partially independent of these factors.

METHODS

In a multiethnic study of 5,598 men and women ages 45 to 84 years old, without baseline CHD, excluding subjects on lipid-lowering medications, triglycerides >400 mg/dl, or missing values, we evaluated associations of HDL-C and nuclear magnetic resonance spectroscopy-measured HDL-P with cIMT and incident CHD (myocardial infarction, CHD death, and angina, n = 227 events; mean 6.0 years follow-up). All models were adjusted for age, sex, ethnicity, hypertension, and smoking.

RESULTS

HDL-C and HDL-P correlated with each other (ρ = 0.69) and LDL-P (ρ = -0.38, -0.25, respectively, p < 0.05 for all). For (1 SD) higher HDL-C (15 mg/dl) or HDL-P (6.64 μmol/l), cIMT differences were - 26.1 (95% confidence interval [CI]: -34.7 to -17.4) μm and -30.1 (95% CI: -38.8 to - 21.4) μm, and CHD hazard ratios were 0.74 (95% CI: 0.63 to 0.88) and 0.70 (95% CI: 0.59 to 0.82), respectively. Adjusted for each other and LDL-P, HDL-C was no longer associated with cIMT (2.3; 95% CI: - 9.5 to 14.2 μm) or CHD (0.97; 95% CI: 0.77 to 1.22), but HDL-P remained independently associated with cIMT (-22.2; 95% CI: - 33.8 to -10.6 μm) and CHD (0.75; 95% CI: 0.61 to 0.93). Interactions by sex, ethnicity, diabetes, and high-sensitivity C-reactive protein were not significant.

CONCLUSIONS

Adjusting for each other and LDL-P substantially attenuated associations of HDL-C, but not HDL-P, with cIMT and CHD. Potential confounding by related lipids or lipoproteins should be carefully considered when evaluating HDL-related risk.

Cardiovascular disease in patients with HIV

The introduction of combination antiretroviral therapy (cART) has substantially decreased mortality among the HIV-infected population. In this setting, cardiovascular disease (CVD) has become a leading cause of morbidity and mortality. Compared with the general population, higher rates of myocardial infarction as well as a high prevalence of subclinical coronary atherosclerosis have been found in the HIV-infected population. It has been suggested that in HIV-infected patients, the atherosclerotic burden is not based solely on traditional cardiovascular risk factors. The interplay of other mechanisms such as chronic inflammation, effects of cART or immune activation after initiation of cART may predispose to accelerated and increased risk of CVD. Effective treatment are available today to reduce CVD in at-risk patients, and therefore early detection of subclinical coronary atherosclerosis is important. However, the mechanisms behind the development of CVD in HIV-infected patients may limit the usefulness of the traditional noninvasive screening tools for CVD used in the general population. This review will focus on the different plausible mechanisms behind the increased risk of CVD and the noninvasive methods by which atherosclerosis may be assessed in the HIV-infected population.

Determinants of low-density lipoprotein particle diameter during antiretroviral therapy including protease inhibitors in HIV-1-infected patients

BACKGROUND

Lipid disorders are frequent in HIV-1-infected patients taking combination antiretroviral therapy (cART) that includes protease inhibitors (PIs). The presence of small dense low-density lipoprotein particles might be an important predictive marker of cardiovascular disease in this setting. This cross-sectional substudy of the ANRS 126 trial was designed to identify variables influencing LDL diameter.

METHODS

We studied 81 stable HIV-1-infected patients with dyslipidaemia (LDL-cholesterol >4.1 mmol/l, triglycerides <8.8 mmol/l) receiving PI-including cART regimens and no lipid-lowering drugs. LDL diameter was assessed by gradient gel electrophoresis. Relationships between LDL diameter and demographic, metabolic and HIV-related variables were identified by using non-parametric univariate tests and multiple linear regression models.

RESULTS

In univariate analysis, LDL diameter was related to demographic variables, triglyceride (TG) levels, high-density lipoprotein cholesterol (HDL-c) levels, and the numbers and duration of exposure to nucleoside reverse transcriptase inhibitors and PIs. In multivariable linear regression analysis, LDL diameter was negatively associated with the TG level (P<0.0001) and positively associated with the HDL-c level (P<0.0001). For each 1-mmol/l increase in TG, LDL diameter fell by 0.281 nm. Conversely, for each 1-mmol/l increase in HDL-c, LDL diameter rose by 1.175 nm.

CONCLUSIONS

Higher TG and lower HDL-c levels are associated with smaller LDL particle diameter. Small-diameter LDL particles could contribute to early atherogenic processes in HIV-1-infected patients on cART.

Inflammation predicts changes in high-density lipoprotein particles and apolipoprotein A1 following initiation of antiretroviral therapy

BACKGROUND

The effects of HIV infection and antiretroviral therapy (ART) on usual lipid levels have been reported. The effects of initiating versus deferring ART on high-density and low-density lipoprotein particle (HDL-P and LDL-P, respectively) concentrations and apolipoprotein (Apo) levels are not well described.

METHODS

In a subgroup of participants not taking ART at study entry who were randomized in the Strategies for Management of Antiretroviral Therapy (SMART) trial to immediately initiate ART ('viral suppression group') or to defer it ('drug conservation group'), lipoprotein particle concentrations and ApoA1 and ApoB levels were measured at baseline and at 2 and 6 months following randomization.

RESULTS

Compared with drug conservation group (n = 126), HDL-P and ApoA1 levels increased among viral suppression participants (n = 128) after starting ART. At 6 months, viral suppression participants had 13% higher total HDL-P (P < 0.001) and 9% higher ApoA1 (P < 0.001). LDL-P, very low density lipoprotein particle, and ApoB did not differ significantly between the viral suppression and drug conservation groups. Among viral suppression participants, predictors of HDL-P and ApoA1 increases included baseline levels of high-sensitivity C-reactive protein (hsCRP) and interleukin 6 (IL-6), but not HIV RNA level, CD4 cell count, or traditional cardiovascular disease risk factors. The effect of starting ART on changes in HDL-P and ApoA1 was greater for those with higher versus lower baseline levels of IL-6 (P = 0.001 and 0.08, respectively, for interaction) or hsCRP (P = 0.01 and 0.04, respectively, for interaction).

CONCLUSION

HDL-P and ApoA1 increase following ART initiation, to a degree that depends on the degree of inflammation present at entry. These findings suggest that activation of inflammatory pathways contribute to HIV-associated changes in HDL.

Biomarkers of immune dysfunction following combination antiretroviral therapy for HIV infection

Combination antiretroviral therapy (cART) has significantly reduced morbidity and mortality of HIV-infected patients, yet their life expectancy remains reduced compared with the general population. Most HIV-infected patients receiving cART have some persistent immune dysfunction characterized by chronic immune activation and premature aging of the immune system. Here we review biomarkers of T-cell activation (CD69, -25 and -38, HLA-DR, and soluble CD26 and -30); generalized immune activation (C-reactive protein, IL-6 and D-dimer); microbial translocation (lipopolysaccharide, 16S rDNA, lipopolysaccharide-binding protein and soluble CD14); and immune dysfunction of specific cellular subsets (T cells, natural killer cells and monocytes) in HIV-infected patients on cART and their relationship to adverse clinical outcomes including impaired CD4 T-cell recovery, as well as non-AIDS clinical events, such as cardiovascular disease.

Current understanding of HIV-associated neurocognitive disorders pathogenesis

PURPOSE OF REVIEW

The present review discusses current concepts of HIV-associated neurocognitive disorders (HAND) in the era of antiretroviral therapy (ART). As the HIV epidemic enters its fourth decade (the second decade of ART), research must address evolving factors in HAND pathogenesis. These include persistent systemic and central nervous system (CNS) inflammation, aging in the HIV-infected brain, HIV subtype (clade) distribution, concomitant use of drugs of abuse, and potential neurotoxicity of ART drugs.

RECENT FINDINGS

Although the severest form of HAND, HIV-associated dementia (HAD), is now rare due to ART, the persistence of milder, functionally important HAND forms persist in up to half of HIV-infected individuals. HAND prevalence may be higher in areas of Africa where different HIV subtypes predominate, and ART regimens that are more effective in suppressing CNS HIV replication can improve neurological outcomes. HAND are correlated with persistent systemic and CNS inflammation, and enhanced neuronal injury due to stimulant abuse (cocaine and methamphetamine), aging, and possibly ART drugs themselves.

SUMMARY

Prevention and treatment of HAND requires strategies aimed at suppressing CNS HIV replication and effects of systemic and CNS inflammation in aging and substance-abusing HIV populations. Use of improved CNS-penetrating ART must be accompanied by evaluation of potential ART neurotoxicity.

Correlation between HIV disease and lipid metabolism in antiretroviral-naïve HIV-infected patients in Japan

Antiretroviral therapy alters lipid metabolism in HIV-infected patients. However, interpreting the impact of HIV infection on lipid metabolism is difficult because of various associated factors, including antiretroviral drugs and demographic characteristics. A few studies have associated HIV infection with lipid metabolism in antiretroviral-naïve HIV-infected patients. Because there were no data in this regard from Japan, the present study examined the impact of HIV infection, as well as demographic and clinical features, on lipid metabolism in antiretroviral-naïve HIV-infected patients in Japan. We performed a cross-sectional study to examine the impact of HIV disease, demographic and clinical characteristics on lipid metabolism among 168 HIV-infected Japanese men who were antiretroviral naïve and who did not have hemophilia, including patients who took medication for dyslipidemia. The mean age of the patients was 45.7 years; 0.6% of the patients took medication to dyslipidemia. The mean CD4 lymphocyte count was 289/μL, the mean baseline log10 HIV viral load was 4.2 HIV-1 RNA copies/mL, and 22% of the patients had a history of AIDS-defining events. A higher HDL-C concentration was associated with a higher CD4 lymphocyte count (p = 0.043). Also, a higher LDL-C concentration was associated with a higher CD4 lymphocyte count (p = 0.003). Infection with HIV was associated with dyslipidemia in antiretroviral-naïve patients. More advanced HIV disease was associated with less favorable lipid homeostatic profiles. These results are similar to findings from other countries.

Lipid and lipoprotein profile in HIV-infected patients treated with lopinavir/ritonavir as a component of the first combination antiretroviral therapy

We characterized lipid and lipoprotein changes associated with a lopinavir/ritonavir-containing regimen. We enrolled previously antiretroviral-naive patients participating in the Swiss HIV Cohort Study. Fasting blood samples (baseline) were retrieved retrospectively from stored frozen plasma and posttreatment (follow-up) samples were collected prospectively at two separate visits. Lipids and lipoproteins were analyzed at a single reference laboratory. Sixty-five patients had two posttreatment lipid profile measurements and nine had only one. Most of the measured lipids and lipoprotein plasma concentrations increased on lopinavir/ritonavir-based treatment. The percentage of patients with hypertriglyceridemia (TG >150 mg/dl) increased from 28/74 (38%) at baseline to 37/65 (57%) at the second follow-up. We did not find any correlation between lopinavir plasma levels and the concentration of triglycerides. There was weak evidence of an increase in small dense LDL-apoB during the first year of treatment but not beyond 1 year (odds ratio 4.5, 90% CI 0.7 to 29 and 0.9, 90% CI 0.5 to 1.5, respectively). However, 69% of our patients still had undetectable small dense LDL-apoB levels while on treatment. LDL-cholesterol increased by a mean of 17 mg/dl (90% CI -3 to 37) during the first year of treatment, but mean values remained below the cut-off for therapeutic intervention. Despite an increase in the majority of measured lipids and lipoproteins particularly in the first year after initiation, we could not detect an obvious increase of cardiovascular risk resulting from the observed lipid changes.

Dyslipidemia and lipid management in HIV-infected patients

PURPOSE OF REVIEW

Dyslipidemia is highly prevalent among patients living with chronic HIV infection and may confer increased risk of cardiovascular disease in this patient population. This review summarizes recent data investigating lipid abnormalities and its management in HIV-infected patients.

RECENT FINDINGS

Studies in the last year have evaluated the effects of various lipid-lowering therapies not previously investigated in the HIV patient population. Rosuvastatin is a potent statin that appears to be well tolerated and effective in HIV-infected patients with hypercholesterolemia.

SUMMARY

Dyslipidemia is common in HIV-infected individuals. Medical therapy of lipid disorders needs to take potential drug-drug interactions of lipid-lowering medications and antiretroviral agents into consideration.

Soluble biomarkers and morbidity and mortality among people infected with HIV: summary of published reports from 1997 to 2010

PURPOSE OF REVIEW

Published articles from 1997 through May 2010 that reported findings on the relationship of soluble biomarkers with clinical outcomes among people infected with HIV were identified, and studies that examined the incremental value (over that of CD4 cell count and HIV RNA level) that biomarkers had for predicting clinical outcomes were summarized.

RECENT FINDINGS

Over 1500 articles were identified on MEDLINE databases that met selected medical subject heading terms. Thirty-eight met criteria for inclusion in the review. Fifteen of the articles were published since 2008. Most evaluated biomarkers reflecting inflammation and immune activation. For 25 studies, the relationship between the biomarker and all-cause mortality was evaluated. Samples stored in specimen repositories were used for many studies, and those that did not usually focused on biomarkers that are measured as part of routine care. Eight of the reports utilized a case-control design and most of these were nested within a cohort study or a clinical trial.

SUMMARY

Establishing the relationship between a biomarker and a clinical outcome is an important step in biomarker evaluation. To advance research on biomarkers relevant to people with HIV, large studies with long follow-up, carefully documented clinical events, and specimen repositories will be needed.

Biomarkers of immune dysfunction in HIV

PURPOSE OF REVIEW

HIV infection is characterized by chronic immune system activation and inflammatory cytokine production. This review will highlight recent developments using plasma and cellular biomarkers of immune system activation and dysfunction to predict mortality and opportunistic disease in HIV-infected individuals.

RECENT FINDINGS

HIV infection results in features characteristic of early aging of the immune system or 'immune senescence', driven by chronic antigen exposure and immune system activation. Microbial translocation of gut bacterial components is associated with chronic immune activation and possibly systemic inflammation. Antiretroviral therapy may not fully normalize this condition. Baseline elevations of certain biomarkers of inflammation or coagulopathy, notably interleukin-6 (IL-6), C-reactive protein (CRP), and D-dimer, have been associated with mortality or opportunistic disease, after adjustment for appropriate variables, in several large randomized clinical trials. It is not known if elevated IL-6 or CRP causes this morbidity and mortality or if they are simply surrogate markers of a global inflammatory state.

SUMMARY

Several inflammatory biomarkers appear to add to our ability to predict mortality or opportunistic disease in HIV-infected individuals. Before biomarkers will be useful, it will be necessary to identify interventions that moderate biomarker levels, and then determine if this moderation attenuates disease outcomes.

Role of biomarkers in predicting CVD risk in the setting of HIV infection?

PURPOSE OF REVIEW

The purpose of this review is to present recent results on biomarkers and risk of cardiovascular disease (CVD) in the general population and to review studies of biomarkers among individuals with HIV infection.

RECENT FINDINGS

Several inflammatory as well as lipid biomarkers are associated with risk of CVD. Biomarkers associated with inflammation such as C-reactive protein and interleukin-6 have been suggested to improve risk stratification among intermediate-risk persons; however, their routine use is not recommended in the general population. Both biomarkers have recently been reported elevated in patients with HIV. Additionally, interleukin-6 and D-dimer have been reported to predict overall mortality among individuals with HIV. However, the utility of other biomarkers to predict CVD among individuals with HIV infection is not clear.

SUMMARY

The risk of CVD is increasing in the HIV-infected population and will increase as this population continues to age. Identification of intermediate-risk individuals using biomarkers will be an important tool for clinicians in the future to be able to treat HIV-infected individuals aggressively. Future studies of biomarkers among individuals with HIV will be needed to help determine the utility of specific markers in predicting CVD risk as well as the mechanism underlying increased CVD risk in the setting of HIV infection.

Plasma levels of soluble CD14 independently predict mortality in HIV infection

BACKGROUND

Chronic human immunodeficiency virus (HIV) infection is associated with intestinal permeability and microbial translocation that contributes to systemic immune activation, which is an independent predictor of HIV disease progression. The association of microbial translocation with clinical outcome remains unknown.

METHODS

This nested case-control study included 74 subjects who died, 120 of whom developed cardiovascular disease and 81 of whom developed AIDS during the Strategies for Management of Anti-Retroviral Therapy (SMART) study with matched control subjects. Intestinal fatty acid binding protein (I-FABP), lipopolysaccharide (LPS), soluble CD14 (sCD14), endotoxin core antibody (EndoCAb), and 16S ribosomal DNA (rDNA) were measured in baseline plasma samples.

RESULTS

Subjects with the highest quartile of sCD14 levels had a 6-fold higher risk of death than did those in the lowest quartile (95% confidence interval, 2.2-16.1; P<.001), with minimal change after adjustment for inflammatory markers, CD4(+) T cell count, and HIV RNA level. No other marker was significantly associated with clinical outcomes. I-FABP, LPS, and sCD14 were increased and EndoCAb was decreased in study subjects, compared with healthy volunteers. sCD14 level correlated with levels of IL-6, C-reactive protein, serum amyloid A and D-dimer.

CONCLUSIONS

sCD14, a marker of monocyte response to LPS, is an independent predictor of mortality in HIV infection. Therapeutic attenuation of innate immune activation may improve survival in patients with HIV infection.

Cardiovascular implications from untreated human immunodeficiency virus infection

Atherosclerotic cardiovascular disease (CVD) has become an important cause of morbidity and mortality among individuals with human immunodeficiency virus (HIV) infection with access to antiretroviral medications, as the risk for AIDS has fallen and life expectancy improved. Traditional CVD risk factors are often more common among individuals with HIV infection, and traditional prevention strategies remain important. Recent data have revealed that untreated HIV infection itself amplifies additional pro-atherogenic mechanisms related to immune activation, inflammation, coagulation, and lipoprotein particle changes (e.g. high-density lipoprotein particles). Some of these mechanisms are attenuated, though incompletely, with antiretroviral therapy (ART)-related suppression of HIV replication. Exposure to ART is also associated with variable toxicity that may simultaneously decrease (via viral suppression) and increase CVD risk. Ultimately, additional adjunctive treatment will be needed to mitigate premature CVD risk among contemporary HIV-infected patients with access to ART.

A pilot study of abacavir/lamivudine and raltegravir in antiretroviral-naïve HIV-1-infected patients: 48-week results of the SHIELD trial

PURPOSE

to evaluate raltegravir plus abacavir/lamivudine in antiretroviral-naïve, HIV-1-infected patients.

METHODS

SHIELD is an ongoing 96-week pilot study of abacavir/lamivudine 600 mg/300 mg once daily with raltegravir 400 mg twice daily among HLA-B*5701-negative adults with screening viral load (VL) > 1,000 copies/mL. HBsAg+ patients were excluded, as were patients with key mutation(s) to any study drug. Virologic failure (VF) was defined as either VL > 400 copies/mL at week 24 or confirmed virologic rebound.

RESULTS

thirty-five patients enrolled (mean age 38.7 years). Most were white males, but 26% self-identified as Hispanic/Latino. At baseline, 34% had VL ≥ 100,000 copies/mL (median, 4.8 log10 copies/mL) and 20% had CD4 cell counts <200 cells/mm3 (median, 301). One patient discontinued due to adverse events (AEs); one patient experienced VF. At week 48, 91% (32/35) had VL <50 and <400 copies/mL by missing/discontinuation equals failure analysis. Median CD4 cell count change from baseline was +247 cells/mm3. Five patients (14%) had treatment-related grade 2-4 AEs; no treatment-related serious AEs were reported. Over 48 weeks, median fasting lipids increased for total (+17%), LDL (+9%), and HDL (+6%) cholesterol but remained stable for triglycerides (-1%) and total:HDL cholesterol ratio (0%).

CONCLUSIONS

in this pilot study, abacavir/lamivudine plus raltegravir was effective and generally well-tolerated over 48 weeks with modest changes in fasting lipids.

HIV, HAART, and lipoprotein particle concentrations in the Women's Interagency HIV Study

BACKGROUND

Changes in lipoprotein particle concentrations, especially greater small low-density lipoprotein particle (LDL-p) and lower small high-density lipoprotein particle (HDL-p) may provide information regarding cardiovascular disease (CVD) risk above and beyond that which is provided by standard lipids. We quantified the association HIV and HAART use had with LDL-p and HDL-p.

METHODS

Cross-sectional study of 1077 individuals classified by HIV/HAART status (361 HIV-uninfected, 128 HIV-infected/HAART naive, 588 HIV-infected/on HAART) enrolled in the Women's Interagency HIV Study. Nuclear magnetic resonance spectroscopy estimated total and subclass lipoprotein particle concentrations. Quantile regression models were used to estimate differences in the 10th, 25th, 50th, 75th, and 90th percentiles of the distributions of lipoprotein particle concentrations between the two HIV-infected exposure groups and HIV-uninfected controls after adjustment for demographic, nonlipid metabolic factors, and standard lipids.

RESULTS

Compared with HIV-uninfected women, those on HAART had greater 75th and 90th percentiles of small LDL-p; there was little difference between HIV-infected/HAART naive and HIV-uninfected women. After adjustment for triglycerides, the association of HAART with greater 75th and 90th percentiles of small LDL-p was attenuated and no longer significant. In contrast, after adjustment for triglycerides, HIV infection irrespective of HAART status remained associated with significantly lower 10th, 25th, 50th, 75th, and 90th percentiles of small HDL-p.

CONCLUSION

Our findings suggest that testing for LDL-p confers little additional information beyond triglycerides levels when assessing CVD risk. Further investigation is needed to examine the role of HDL-p in the link between HIV and CVD in women.

Biomarkers and HIV-associated cardiovascular disease

PURPOSE OF REVIEW

Our goal is to summarize recent literature on biomarkers of cardiovascular disease (CVD) in the setting of HIV infection with an emphasis on those associated with clinical events.

RECENT FINDINGS

Epidemiological data have demonstrated that HIV infection is associated with increases in well established markers of inflammation and thrombosis, and levels of high sensitivity C-reactive protein, interleukin-6, and D-dimer predict CVD and mortality risk in HIV cohorts. Levels of interleukin-6, D-dimer and endothelial adhesion molecules increase when antiretroviral therapy is interrupted, suggesting that HIV replication may be driving CVD risk in this context. However, data on changes in many CVD biomarkers after starting antiretroviral therapy are inconsistent or lacking. Finally, high-density lipoprotein particles may be more informative than other lipoprotein measures for CVD risk specifically among individuals with HIV infection.

SUMMARY

Biomarkers of inflammation and thrombosis have the potential to improve CVD risk stratification beyond traditional and HIV-specific factors, and may prove useful for evaluating CVD prevention strategies for individuals with HIV infection.

Short communication: contribution of the immunovirological state and traditional cardiovascular risk factors to low HDL-cholesterol in HIV patients

The prevalence of low HDL-C levels in an HIV population and its related factors was investigated. We undertook a multicenter, cross-sectional study of all HIV patients on regular follow-up in five hospitals (Southern Spain). A physical examination and fasting laboratory analysis were performed and a questionnaire about cardiovascular risk factors was provided. One thousand and seventy-two patients were included, 43.8% of whom had low HDL-C levels. The prevalence of low HDL-C was higher among patients diagnosed with AIDS, those not on antiretroviral therapy, those with a detectable HIV viral load, those with CD4 cell counts ≤350 cells/μl, smokers, and those with hypertriglyceridemia. For patients on antiretroviral therapy, the prevalence of low HDL-C was higher for those on protease inhibitors than those taking nonnucleoside reverse transcriptase inhibitors. In the multivariate analysis, low HDL-C levels were associated with tobacco use (OR 1.37, 95% CI 1.04-1.8; p = 0.04), hypertriglyceridemia (OR 2.94, 95% CI 2.2-3.8; p < 0.00001), CD4 cells count ≤350 cells/μl (OR 1.74, 95% CI 1.2-2.3; p < 0.0001), and a detectable HIV viral load (OR 1.85, 95% CI 1.3-2.5; p < 0.0001). The immunological and virological conditions, in addition to traditional cardiovascular risk factors such as tobacco use and hypertriglyceridemia, affect HDL-C levels in HIV-infected patients. For patients on antiretroviral therapy, the use of protease inhibitors is associated with a higher probability of low levels of HDL-C. Although it is not clear if the higher HDL-C levels associated with antiretroviral use are surrogates for decreased cardiovascular disease risk, this may be another reason to start antiretroviral therapy earlier.

Mutation of the ATP cassette binding transporter A1 (ABCA1) C-terminus disrupts HIV-1 Nef binding but does not block the Nef enhancement of ABCA1 protein degradation

HIV-1 infection and antiretroviral therapy are associated with a dyslipidemia marked by low levels of high-density lipoprotein and increased cardiovascular disease, but it is unclear whether virion replication plays a causative role in these changes. The HIV-1 Nef protein can impair ATP cassette binding transporter A1 (ABCA1) cholesterol efflux from macrophages, a potentially pro-atherosclerotic effect. This viral inhibition of efflux was correlated with a direct interaction between ABCA1 and Nef. Here, we defined the ABCA1 domain required for the Nef-ABCA1 protein-protein interaction and determined whether this interaction mediates the ability of Nef to downregulate ABCA1. Nef expressed in HEK 293 cells strongly inhibited ABCA1 efflux and protein levels but did not alter levels of cMIR, another transmembrane protein. Analysis of a panel of ABCA1 C-terminal mutants showed Nef binding required the ABCA1 C-terminal amino acids between positions 2225 and 2231. However, the binding of Nef to ABCA1 was not required for inhibition because the C-terminal ABCA1 mutants that did not bind Nef were still downregulated by Nef. Given this discordance, the mechanism of downregulation was investigated and was found to involve the acceleration of ABCA1 protein degradation but did not to depend upon the ABCA1 PEST sequence, which mediates the calpain proteolysis of ABCA1. Furthermore, it did not associate with a Nef-dependent induction of signaling through the unfolded protein response but was significantly dependent upon proteasomal function and could act on an ABCA1 mutant that fails to exit the endoplasmic reticulum. In summary, we show that Nef downregulates ABCA1 function by a post-translational mechanism that stimulates ABCA1 degradation but does not require the ability of Nef to bind ABCA1.

Changes in lipids and lipoprotein particle concentrations after interruption of antiretroviral therapy

BACKGROUND

The effect of interruption of antiretroviral therapy (ART) on lipoprotein particle subclasses has not been studied. We examined short-term changes in lipids and lipoprotein particles among 332 HIV-infected individuals randomized to interrupt or continue ART in the "Strategies for Management of Antiretroviral Therapy" trial.

METHODS

Lipids and lipoprotein particles measured by nuclear magnetic resonance spectroscopy were compared between randomized groups at month 1; associations with inflammatory and coagulation markers (high sensitivity C-reactive protein; interleukin 6; amyloid A; amyloid P; D-dimer; prothrombin fragment 1 + 2) were assessed.

RESULTS

Compared with continuation of ART, treatment interruption resulted in substantial declines in total, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, and triglyceride, at month 1 but had little net effect on total/HDL cholesterol ratio [baseline-adjusted mean difference [95% confidence interval (CI)] interruption versus continuation arms: -0.10 (-0.59 to 0.38); P = 0.67]. ART interruption resulted in declines in total, large, and medium very low density lipoprotein (VLDL) particle concentrations (VLDL-p) and total and medium HDL-p. However, there was no change in small HDL-p [baseline-adjusted percentage difference between arms: -4.6% (-13.1%, +5.1% ); P = 0.35], small LDL-p [-5.0% (-16.9%, +8.6%); P = 0.45], or other LDL-p subclasses. Changes in lipid parameters on ART interruption did not differ according to baseline ART class (protease inhibitor versus non-nucleoside reverse transcriptase inhibitor) but were negatively associated both with changes in HIV viral load and with changes in inflammatory and coagulation markers, particularly D-dimer.

CONCLUSIONS

These results suggest that ART interruption does not favorably influence overall lipid profile: there was little net effect on total/HDL cholesterol ratio, and no change in small LDL-p or small HDL-p, the lipoprotein particle subclasses most consistently linked to coronary risk. Short-term declines in lipid parameters after ART interruption were not associated with class of ART and may be linked to increases in viral replication, inflammation and coagulation.

Short-term effects of extended-release niacin on endothelial function in HIV-infected patients on stable antiretroviral therapy

OBJECTIVE

To assess the short-term effects of extended-release niacin (ERN) on endothelial function in HIV-infected patients with low high-density lipoprotein-cholesterol (HDL-c) levels.

METHODS

Randomized controlled study to determine the short-term effects of ERN on endothelial function, measured by flow-mediated vasodilation (FMD) of the brachial artery, in HIV-infected adults with low HDL-c. Participants on stable HAART with fasting HDL-c less than 40 mg/dl and low-density lipoprotein-cholesterol less than 130 mg/dl were randomized to ERN or control arms. ERN treatment started at 500 mg/night and titrated to 1500 mg/night for 12 weeks. Controls received the same follow-up but were not given ERN (no placebo). Participants were excluded if they had a history of cardiac disease, uncontrolled hypertension, diabetes mellitus, or were on lipid-lowering medications such as statins and fibrates. Change in FMD was compared between arms with respect to baseline HDL-c.

RESULTS

Nineteen participants were enrolled: 89% men, median age 50 years, 53% white/non-Hispanic, median CD4 cell count 493 cells/microl, and 95% of them had HIV RNA below 50 copies/ml. Participants receiving ERN had a median HDL-c (interquartile range) increase of 3.0 mg/dl (0.75 to 5.0) compared with -1.0 mg/dl in controls (-6.0 to 2.5), a P value is equal to 0.04. The median change in FMD was 0.91% (-2.95 to 2.21) for ERN and -0.48% (-2.65 to 0.98) for controls (P = 0.67). However, end of study FMD for ERN was significantly different from controls after adjusting for baseline differences in FMD and HDL-c, 6.36% (95% confidence interval 4.85-7.87) and 2.73% (95% confidence interval 0.95-4.51) respectively, a P value is equal to 0.048.

CONCLUSION

This pilot study demonstrated that short-term niacin therapy could improve endothelial function in HIV-infected patients with low HDL-c.

High-density lipoprotein particles and markers of inflammation and thrombotic activity in patients with untreated HIV infection

BACKGROUND

Untreated human immunodeficiency virus (HIV) infection is associated with changes in blood lipids, inflammation, thrombotic activity, and increased risk for cardiovascular disease.

METHODS

We studied high-density lipoprotein particle (HDLp) concentrations and inflammatory (high-sensitivity C-reactive protein [hsCRP] and interleukin [IL] 6), endothelial activation (E-selectin and soluble intercellular adhesion molecule-1 [sICAM-1]), and thrombotic (fibrinogen and D-dimer) biomarkers in a group of 32 untreated HIV-infected and 29 uninfected persons. Differences in the levels of blood lipids and biomarkers by HIV status were examined before and after adjustment for age, sex, race/ethnicity, smoking status, body mass index, and the presence of hepatitis C.

RESULTS

HIV-infected participants, compared with uninfected participants, had lower HDL cholesterol (HDLc) levels (-26%) and HDLp numbers (-21%), with reductions in large (-50%) and small (-20%) HDLp, specifically (P < or = .01 for all). A trend was present for higher total cholesterol (P = .15 and triglyceride levels (P = .11) among individuals with HIV infection. Levels of IL-6, sICAM-1, and D-dimer were 65%-70% higher in HIV-infected participants (P < or = .02 for all). Covariate adjustment did not diminish these associations. For HIV-infected participants, total and small HDLp (respectively) tended to correlate inversely with levels of IL-6 (P = .08 and P = .02), sICAM-1 (P < .01 for both) and D-dimer (P = .03 and p < .01).

CONCLUSIONS

Persons with untreated HIV infection have lower HDLp (primarily large and small HDLp) and higher IL-6, sICAM-1, and D-dimer levels, and the relationship of these markers to HIV-mediated atherosclerotic risk requires further study.

Lipid abnormalities in a never-treated HIV-1 subtype C-infected African population

Dyslipidemia has been documented worldwide among human immunodeficiency virus-infected (HIV) individuals and these changes are reminiscent of the metabolic syndrome (MetS). In South Africa, with the highest number of HIV infections worldwide, HIV-1 subtype C is prevalent, while HIV-1 subtype B (genetically different from C) prevails in Europe and the United States. We aimed to evaluate if HIV infection (subtype C) is associated with dyslipidemia, inflammation and the occurrence of the MetS in Africans. Three hundred newly diagnosed HIV-infected participants were compared to 300 age, gender, body mass index and locality matched uninfected controls. MetS was defined according to the Adult Treatment Panel III (ATP III) and International Diabetes Federation (IDF) criteria. The HIV-infected group showed lower high density lipoprotein cholesterol (1.23 vs. 1.70 mmol/L) and low density lipoprotein cholesterol (2.60 vs. 2.80 mmol/L) and higher triglycerides (1.29 vs. 1.15 mmol/L), C-reactive protein (3.31 vs. 2.13 mg/L) and interleukin 6 (4.70 vs. 3.72 pg/L) levels compared to the uninfected group. No difference in the prevalence of the MetS was seen between the two groups (ATP III, 15.2 vs. 11.5%; IDF, 21.1 vs. 22.6%). This study shows that HIV-1 subtype C is associated with dyslipidemia, but not with a higher incidence of MetS in never antiretroviral-treated HIV-infected Africans.