Endothelial activation markers are linked to HIV status and are independent of antiretroviral therapy and lipoatrophy

HIV Infection, Antiretroviral Drugs, and the Vascular Endothelium

Endothelial cell activation, injury, and dysfunction underlies the pathophysiology of vascular diseases and infections associated with vascular dysfunction, including human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome. Despite viral suppression with combination antiretroviral therapy (ART), people living with HIV (PLWH) are prone to many comorbidities, including neurological and neuropsychiatric complications, cardiovascular and metabolic diseases, premature aging, and malignancies. HIV and viral proteins can directly contribute to the development of these comorbidities. However, with the continued high prevalence of these comorbidities despite viral suppression, it is likely that ART or some antiretroviral (ARVs) drugs contribute to the development and persistence of comorbid diseases in PLWH. These comorbid diseases often involve vascular activation, injury, and dysfunction. The purpose of this manuscript is to review the current literature on ARVs and the vascular endothelium in PLWH, animal models, and in vitro studies. I also summarize evidence of an association or lack thereof between ARV drugs or drug classes and the protection or injury/dysfunction of the vascular endothelium and vascular diseases.

Endothelial dysfunction, a predictor of cardiovascular disease in HIV patients on antiretroviral therapy: A systematic review and meta-analysis

Aim Although antiretroviral therapy (ART) is available, the rate of new HIV infections is alarming. With this trend, it is anticipated that the use of ART will continue to rise, potentially resulting in associated vascular disorders. Therefore, we aimed to examine the impact of ART on endothelial function in people living with HIV (PLHIV), a predictor of cardiovascular diseases.

METHOD

A comprehensive search for evidence was made on PubMed and Scopus on May 06, 2023, following the Preferred Reporting Items for Systematic Review and Meta-analysis. Cochrane and Newcastle-Ottawa quality assessment scales were used to evaluate quality, while the metaHun web tool and Review Manager version 5.4.1 were used for analysis. Subgroup, sensitivity, and publication bias were conducted for each outcome measure.

RESULTS

We identified 37 studies, including a sample size of 3700 with 2265 individuals on ART. The analyzed evidence showed a large significant effect of ART on vascular cell adhesion molecule-1, with a standardized mean difference (SMD) of -1.23 (95 % CI: -1.72, -0.74; p = 0.0013). Similarly, a significant medium effect of ART was observed on intercellular cell adhesion molecule-1 in PLHIV, with an SMD of -1.28 (95 % CI: -2.00, -0.56; p = 0.0231) compared to the control group. Furthermore, ART exhibited a significant but small effect on flow-mediated dilation (FMD) with an SMD of -0.40 (95 % CI: -0.62, -0.19, p = 0.0159).

CONCLUSION

Our findings show an improved endothelial function in PLHIV on ART, as demonstrated by reduced adhesion molecules; however, ART exhibited a small effect on FMD, thus suggesting PLHIV on ART may still be at risk of endothelial dysfunction and further cardiovascular diseases.

Venous thromboembolism in viral diseases: A comprehensive literature review

Venous thromboembolism (VTE) is known to be a common respiratory and/or cardiovascular complication in hospitalized patients with viral infections. Numerous studies have proven human immunodeficiency virus infection to be a prothrombotic condition. An elevated VTE risk has been observed in critically ill H1N1 influenza patients. VTE risk is remarkably higher in patients infected with the Hepatitis C virus in contrast to uninfected subjects. The elevation of D-dimer levels supported the association between Chikungunya and the Zika virus and the rise of clinical VTE risk. Varicella-zoster virus is a risk factor for both cellulitis and the consequent invasive bacterial disease which may take part in thrombotic initiation. Eventually, hospitalized patients infected with the coronavirus disease of 2019 (COVID-19), the cause of the ongoing worldwide pandemic, could mainly suffer from an anomalous risk of coagulation activation with enhanced venous thrombosis events and poor quality clinical course. Although the risk of VTE in nonhospitalized COVID-19 patients is not known yet, there are a large number of guidelines and studies on thromboprophylaxis administration for COVID-19 cases. This study aims to take a detailed look at the effect of viral diseases on VTE, the epidemiology of VTE in viral diseases, and the diagnosis and treatment of VTE.

Effect of Antiretroviral Therapy on Neutrophil Oxidative Burst in Children

OBJECTIVE

To ascertain the effect of human immunodeficiency virus (HIV) infection, as well as, antiretroviral therapy (ART) on neutrophil oxidative burst in children.

METHODS

Fifty-five children living with HIV infection (30 receiving ART for ≥ 2 y, 25 treatment-naïve) and 30 healthy controls, aged 18 mo-18 y, were assessed for hemogram and neutrophil oxidative burst. The treatment-naïve children were followed up and the above tests were repeated after 6 mo of ART.

RESULTS

Mean (SD) serum MPO activity at 6 mo after ART [32.1 (± 19.9) U/L] was comparable to that at disease onset [17.2 (± 23.0) U/L], although it was significantly higher compared to that in children on ART ≥ 2 y [13.3 (± 15.8) U/L] and controls [12.1 (± 11.9) U/L]. Median fluorescence intensity (MFI) of unstimulated DHR was highest at 6 mo after ART and in the treatment-naïve group, which was significantly higher than in the controls, as well as, children receiving ART ≥ 2 y. Stimulation index was highest in the control group [442.4 (341.9-562.9)], which was comparable to that in children on ART ≥ 2 y [304.2 (153.2-664.8)], but was significantly higher than the treatment-naïve cohort [266.1 (148.2-339.4)] and children on ART for 6 mo [318.8 (154.9-395.6)].

CONCLUSION

A hyperinflammatory state caused by an increased serum myeloperoxidase enzyme activity and increased basal neutrophil oxidative burst was seen in untreated HIV infection and during initial 6 mo of ART. ART given for ≥ 2 y normalized the impaired neutrophilic phagocytic functions.

HIV, Combination Antiretroviral Therapy, and Vascular Diseases in Men and Women

Thanks to the advent of combination antiretroviral therapy (cART), people living with human immunodeficiency virus (HIV) (PLWH) experienced a marked increase in life expectancy but are now at higher risk for cardiovascular disease (CVD), the current leading cause of death in PLWH on cART. Although HIV preponderantly affects men over women, manifestations of HIV-related CVD differ by sex with women experiencing greater risks than men. Despite extensive investigation, the etiopathology of CVD, notably the respective contribution of viral infection and cART, remain ill-defined. However, both viral infection and cART have been reported to contribute to endothelial dysfunction, the precursor and major cause of atherosclerosis-associated CVD, through mechanisms involving endothelial cell activation, inflammation, and oxidative stress, all leading to reduced nitric oxide bioavailability. Therefore, preserving endothelial function in PLWH on cART should be a main target to reduce CVD morbidity and mortality, notably in females.

Plasma sVCAM-1, antiretroviral therapy and mortality in HIV-1-infected West African adults

OBJECTIVES

We report the association between pre-antiretroviral therapy (pre-ART) soluble vascular cell adhesion molecule-1 (sVCAM-1) levels and long-term mortality in HIV-infected West African adults participating in a trial of early ART in West Africa (Temprano ANRS 12136 trial).

METHODS

The ART-naïve HIV-infected adults were randomly assigned to start ART immediately or defer ART until the WHO criteria were met. Participants who completed the trial follow-up were invited to participate in a post-trial phase (PTP). The PTP end-point was all-cause death. We used multivariable Cox proportional models to analyse the association between baseline sVCAM-1 and all-cause death, adjusting for ART strategy, sex, CD4 count, plasma HIV-1 RNA and peripheral blood mononuclear cell HIV-1 DNA levels.

RESULTS

In all, 954 adults (77% women, median CD4 count of 387 cells/μL) were randomly assigned to start ART immediately (n = 477) or to defer initiation of ART (n = 477). They were followed for a median of 5.8 years [interquartile range (IQR): 5.2-6.3]. In multivariable analysis, the risk of death was significantly associated with baseline sVCAM-1 [≥1458 vs. < 1458 ng/mL; adjusted hazard ratio = 2.86, 95% confidence interval (CI): 1.60-5.11]. The 6-year probability of death rates were 14.4% (95%CI: 9.1-22.6) and 9.4% (5.4-16.1) in patients with baseline sVCAM-1 ≥ 1458 ng/mL randomized to deferred and immediate ART, respectively, and 3.8% (2.2-6.5) and 3.5% (1.9-6.3) in patients with baseline sVCAM-1 < 1458 ng/mL randomized to deferred and immediate ART. The median difference between pre-ART and 12-month sVCAM-1 levels in patients randomized to immediate ART was -252 (IQR: -587 to -61).

CONCLUSIONS

Pre-ART sVCAM-1 levels were significantly associated with mortality, independently of whether ART was started immediately or deferred, but they significantly decreased after 12 months of ART.

Statin exposure and risk of cancer in people with and without HIV infection

OBJECTIVE

To determine whether statin exposure is associated with decreased cancer and mortality risk among persons with HIV (PWH) and uninfected persons. Statins appear to have immunomodulatory and anti-inflammatory effects and may reduce cancer risk, particularly among PWH as they experience chronic inflammation and immune activation.

DESIGN

Propensity score-matched cohort of statin-exposed and unexposed patients from 2002 to 2017 in the Veterans Aging Cohort Study (VACS), a large cohort with cancer registry linkage and detailed pharmacy data.

METHODS

We calculated Cox regression hazard ratios (HRs) and 95% confidence intervals (CI) associated with statin use for all cancers, microbial cancers (associated with bacterial or oncovirus coinfection), nonmicrobial cancers, and mortality.

RESULTS

:The propensity score-matched sample (N = 47 940) included 23 970 statin initiators (31% PWH). Incident cancers were diagnosed in 1160 PWH and 2116 uninfected patients. Death was reported in 1667 (7.0%) statin-exposed, and 2215 (9.2%) unexposed patients. Statin use was associated with 24% decreased risk of microbial-associated cancers (hazard ratio 0.76; 95% CI 0.69-0.85), but was not associated with nonmicrobial cancer risk (hazard ratio 1.00; 95% CI 0.92-1.09). Statin use was associated with 33% lower risk of death overall (hazard ratio 0.67; 95% CI 0.63-0.72). Results were similar in analyses stratified by HIV status, except for non-Hodgkin lymphoma where statin use was associated with reduced risk (hazard ratio 0.56; 95% CI 0.38-0.83) for PWH, but not for uninfected (P interaction = 0.012).

CONCLUSION

In both PWH and uninfected, statin exposure was associated with lower risk of microbial, but not nonmicrobial cancer incidence, and with decreased mortality.

[Thromboembolic manifestations in 36 HIV-infected patients in West Africa]

Chez les patients infectés par le VIH, la maladie thromboembolique est une complication dont le risque est accru. En Côte d'Ivoire, dans le service de référence de prise en charge médicale des personnes atteintes du VIH/SIDA, aucune étude n'a été menée sur la question. L'objectif de notre étude est de décrire les manifestations thromboemboliques colligées dans le Service des Maladies Infectieuses et Tropicales (SMIT) chez les patients infectés par le VIH, traités ou non par les antirétroviraux. Il s'est agi d'une étude rétrospective des dossiers de patients infectés par le VIH, hospitalisés, et présentant une thrombose veineuse profonde (TVP), artérielle et/ou une embolie pulmonaire de la période de janvier 2005 à juillet 2015. Le diagnostic a été posé par l'écho-Doppler des vaisseaux et/ou l'angioscanner thoracique. L'analyse a porté sur les aspects diagnostiques, thérapeutiques et évolutifs. Les dossiers de 36 patients dont 23 femmes (64%), sex-ratio H/F à 0,57, et âge moyen de 43±12 ans ont été retenus. Les thromboses veineuses profondes (TVP) ont été retrouvées chez 26 (72,2%) patients, des embolies pulmonaires (EP) chez neuf (25%) patients, une thrombose artérielle chez un patient (2,8%). La TVP était unilatérale dans 81% des cas et plus située à gauche (77%). L'EP était unilatérale et à droite dans 100% des cas et la thrombose artérielle était bilatérale dans 2,7% des cas. Chez les patients atteints de TVP, la veine fémorale (39%) et la veine poplitée (35%) étaient les sièges plus fréquents de thrombose. L'EP concernait les artères pulmonaires dans 77,8% des cas et la thrombose artérielle concernait les carotides internes gauche et droite. La majorité des patients était sous traitement antirétroviral (69%). Les infections opportunistes fréquemment associées étaient les candidoses orales (31%) et la tuberculose (33%). L'évolution a été marquée par neuf décès (25%). Cette étude rapporte une fréquence élevée des TVP au cours de l'infection à VIH. D'autres études s'avèrent nécessaires pour mieux appréhender le rôle du VIH dans la survenue de la maladie thromboembolique.

Metabolic and Cardiovascular Complications in HIV/HCV-Co-infected Patients

PURPOSE OF REVIEW

Fifteen to thirty percent of HIV-infected persons in North America and Europe are co-infected with chronic hepatitis C (HCV). The latter is associated with a significant number of extra-hepatic metabolic complications that could compound HIV-associated increased cardiovascular risk. This article reviews the basic science and epidemiologic and clinical evidence for increased cardio-metabolic risk among HIV/HCV-co-infected patients and discusses potential underlying mechanisms. We will finally review the impact of control of HCV viremia on the cardio-metabolic morbidity and mortality of HIV/HCV-co-infected patients.

RECENT FINDINGS

HCV infection is associated with a number of immune-related complications such as cryoglobulinemia but also metabolic complications including dyslipidemias, hepatic steatosis, insulin resistance, diabetes, and chronic kidney disease. The incidence of these complications is higher among HIV-co-infected patients and might contribute to increased mortality. The potential mechanisms of increased cardiovascular risk among HIV/HCV-co-infected subjects include endothelial dysfunction, chronic inflammation and immune activation, the cardio-metabolic effects of HCV-induced hepatic steatosis and fibrosis or insulin resistance, and chronic kidney disease. However, epidemiologic studies show discordant findings as to whether HCV co-infection further increases the risk of atherosclerotic cardiovascular diseases (acute myocardial infarctions and strokes) among HIV-infected patients. Nonetheless, successful treatment of HCV is associated with significant improvements in cardio-metabolic risk factors including diabetes mellitus. HCV co-infection is associated with a higher incidence of metabolic complications-and likely increased risk of cardiovascular events-that might contribute to increased mortality in HIV. These appear to improve with successful HCV therapy.

Coagulation imbalance and neurocognitive functioning in older HIV-positive adults on suppressive antiretroviral therapy

OBJECTIVES

The aim of this study was to compare plasma biomarkers of coagulation between HIV-infected individuals and HIV-uninfected controls and to assess the impact of disturbances in coagulation on neurocognitive functioning in HIV.

DESIGN

A cross-sectional study of 66 antiretroviral therapy treated, virally suppressed, HIV-infected and 34 HIV-uninfected older (≥50 years of age) adults.

METHODS

Participants completed standardized neurobehavioral and neuromedical assessments. Neurocognitive functioning was evaluated using a well validated comprehensive neuropsychological battery. Plasma biomarkers associated with procoagulation (fibrinogen, p-selectin, tissue factor and von Willebrand factor), anticoagulation (antithrombin, protein C and thrombomodulin), fibrinolysis (d-dimer, plasminogen activator inhibitor-1 and plasminogen) were collected. Multivariable linear regression was used to test the interaction of HIV and coagulation on neurocognitive functioning.

RESULTS

Most participants were male (78.0%) and non-Hispanic white (73.0%) with a mean age of 57.8 years. Among HIV-infected participants, mean estimated duration of HIV infection was 19.4 years and median current CD4 cell count was 654 cells/μl. Levels of soluble biomarkers of procoagulation, anticoagulation and fibrinolysis were comparable between the HIV serostatus groups. Coagulation and HIV had an interacting effect on neurocognitive functioning, such that greater coagulation imbalance was associated with poorer neurocognitive functioning among the HIV-infected participants. The moderating effect of coagulation on neurocognition was driven by procoagulant but not anticoagulant or fibrinolytic biomarkers.

CONCLUSIONS

Elevated levels of procoagulants may exert a particularly detrimental effect on neurocognitive functioning among older HIV-infected persons. A better understanding of the specific role of coagulation in the cause of HIV-associated neurocognitive disorders may lead to treatments aimed at reducing coagulopathy, thereby improving neurocognitive outcomes.

Immune activation in the course of HIV-1 infection: Causes, phenotypes and persistence under therapy

Systemic immune activation is a striking consequence of HIV-1 infection. Even in virologically suppressed patients, some hyperactivity of the immune system and even of the endothelium and of the coagulation pathway may persist. Apart from immune deficiency, this chronic activation may contribute to various morbidities including atherothrombosis, neurocognitive disorders, liver steatosis and osteoporosis, which are currently main challenges. It is therefore of major importance to better understand the causes and the phenotypes of immune activation in the course of HIV-1 infection. In this review we will discuss the various causes of immune activation in HIV-1 infected organisms: the presence of the virus together with other microbes, eventually coming from the gut, CD4+ T cell lymphopenia, senescence and dysregulation of the immune system, and/or genetic factors. We will also describe the activation of the immune system: CD4+ and CD8+ T cells, B cells, NKT and NK cells, dendritic cells, monocytes and macrophages, and neutrophils of the inflammation cascade, as well as of the endothelium and the coagulation system. Finally, we will see that antiretroviral therapy reduces the hyperactivity of the immune and coagulation systems and the endothelial dysfunction, but often does not abolish it. A better knowledge of this phenomenon might help us to identify biomarkers predictive of non AIDS-linked comorbidities, and to define new strategies aiming at preventing their emergence.

Current Efavirenz (EFV) or ritonavir-boosted lopinavir (LPV/r) use correlates with elevate markers of atherosclerosis in HIV-infected subjects in Addis Ababa, Ethiopia

BACKGROUND

HIV patients on antiretroviral therapy have shown elevated incidence of dyslipidemia, lipodystrophy, and cardiovascular disease (CVD). Most studies, however, focus on cohorts from developed countries, with less data available for these co-morbidities in Ethiopia and sub-Saharan Africa.

METHODS

Adult HIV-negative (n = 36), treatment naïve (n = 51), efavirenz (EFV)-treated (n = 91), nevirapine (NVP)-treated (n = 95), or ritonavir-boosted lopinavir (LPV/r)-treated (n=44) subjects were recruited from Black Lion Hospital in Addis Ababa, Ethiopia. Aortic pressure, augmentation pressure, and pulse wave velocity (PWV) were measured via applanation tonometry and carotid intima-media thickness (cIMT) and carotid arterial stiffness, and brachial artery flow-mediated dilation (FMD) were measured via non-invasive ultrasound. Body mass index, waist-to-hip circumference ratio (WHR), skinfold thickness, and self-reported fat redistribution were used to quantify lipodystrophy. CD4+ cell count, plasma HIV RNA levels, fasting glucose, total-, HDL-, and LDL-cholesterol, triglycerides, hsCRP, sVCAM-1, sICAM-1, leptin and complete blood count were measured.

RESULTS

PWV and normalized cIMT were elevate and FMD impaired in EFV- and LPV/r-treated subjects compared to NVP-treated subjects; normalized cIMT was also elevated and FMD impaired in the EFV- and LPV/r-treated subjects compared to treatment-naïve subjects. cIMT was not statistically different across groups. Treated subjects exhibited elevated markers of dyslipidemia, inflammation, and lipodystrophy. PWV was associated with age, current EFV and LPV/r used, heart rate, blood pressure, triglycerides, LDL, and hsCRP, FMD with age, HIV duration, WHR, and glucose, and cIMT with age, current EFV use, skinfold thickness, and blood pressure.

CONCLUSIONS

Current EFV- or LPV/r-treatment, but not NVP-treatment, correlated with elevated markers of atherosclerosis, which may involve mechanisms distinct from traditional risk factors.

Viremia copy-years as a predictive marker of all-cause mortality in HIV-1-infected patients initiating a protease inhibitor-containing antiretroviral treatment

BACKGROUND

Viremia copy-years (VCY) has been reported as a short-term predictor of mortality. We evaluated the association of this parameter with 10-year outcome within the APROCO-COPILOTE cohort.

METHODS

Prospective data from 1281 HIV-1-infected patients who started a first protease inhibitor-containing regimen in 1997-1999 were analyzed. Patients with baseline plasma viral load (pVL) > 500 copies per milliliter and at least 2 pVL measures from the eighth month of follow-up were selected. VCY was calculated individually over the follow-up as the area under the pVL curve. Multivariate Cox models analyzed the relation between all-cause mortality and the following variables: age, sex, geographical origin, transmission group, HIV infection duration, ART-naive, pVL at baseline, time-dependent CD4 count, and VCY.

RESULTS

Nine hundred seventy-nine patients were followed up for a median of 10 years (interquartile range: 5-11.5). At baseline, median (interquartile range) values for duration of HIV infection, pVL, and CD4 cell count were 43 (4-95) months, 4.6 (3.9-5.2) log10 copies per milliliter, and 278 (125-416) cells per cubic millimeter, respectively. At censoring date, 77 patients (8%) had died. VCY >1.4 log10 copies × yrs/mL was an independent predictor of death (hazard ratio: 2.0; 95% confidence interval: 1.2 to 3.5), which was no longer the case after adjustment for the latest pVL value [risk ratio (RR): 1.2 for 1 additional log10 copies per milliliter; 95% confidence interval: 1.1 to 1.4].

CONCLUSIONS

VCY was associated with mortality in HIV-infected patients under combined antiretroviral therapy but did not overweigh the predictive value of the latest pVL. VCY might be more useful as a marker of persistent viral replication than for routine clinical care.

Risk of coronary heart disease in patients with HIV infection

The lives of individuals infected with HIV who have access to combination antiretroviral therapy (cART) are substantially prolonged, which increases the risk of developing non-AIDS comorbidities, including coronary heart disease (CHD). In Europe and the USA, individuals with HIV infection have a ∼1.5-fold increased risk of myocardial infarction relative to uninfected individuals. In Africa, the relative risk of myocardial infarction is unknown, but broadened access to life-extending cART suggests that rates of CHD will rise in this and other resource-constrained regions. Atherogenesis in HIV is affected by complex interactions between traditional and immune risk factors. cART has varied, regimen-specific effects on metabolic risk factors. Overall, cART seems to lessen proatherogenic immune activation, but does not eliminate it even in patients in whom viraemia is suppressed. Current strategies to decrease the risk of CHD in individuals infected with HIV include early initiation of cART regimens with the fewest metabolic adverse effects, and careful management of traditional CHD risk factors throughout treatment. Future strategies to prevent CHD in patients with HIV infection might involve the use of HIV-tailored CHD risk-prediction paradigms and the administration of therapies alongside cART that will further decrease proatherogenic HIV-specific immune activation.

The effect of HIV infection on the host response to bacterial sepsis

Bacterial sepsis is an important cause of morbidity and mortality in patients with HIV. HIV causes increased susceptibility to invasive infections and affects sepsis pathogenesis caused by pre-existing activation and exhaustion of the immune system. We review the effect of HIV on different components of immune responses implicated in bacterial sepsis, and possible mechanisms underlying the increased risk of invasive bacterial infections. We focus on pattern recognition receptors and innate cellular responses, cytokines, lymphocytes, coagulation, and the complement system. A combination of factors causes increased susceptibility to infection and can contribute to a disturbed immune response during a septic event in patients with HIV. HIV-induced perturbations of the immune system depend on stage of infection and are only in part restored by combination antiretroviral therapy. Immunomodulatory treatments currently under development for sepsis might be particularly beneficial to patients with HIV co-infection because many pathogenic mechanisms in HIV and sepsis overlap.

LL-37 concentrations and the relationship to vitamin D, immune status, and inflammation in HIV-infected children and young adults

Antimicrobial peptide LL-37 is produced in response to active vitamin D to exert immunomodulatory effects and inhibits HIV replication in vitro. To date, no studies have investigated LL-37 in HIV-infected patients. This study sought to investigate LL-37 and the relationship to 25-hydroxyvitamin D [25(OH)D] and HIV-related variables in this population. HIV-infected subjects and healthy controls ages 1-25 years old were prospectively enrolled in this cross-sectional study. Fasting plasma LL-37 and 25(OH)D concentrations were measured in duplicate with ELISA. HIV(+) subjects (36 antiretroviral therapy (ART)-experienced subjects; 27 ART-naïve subjects) and 31 healthy controls were enrolled. Overall, 93% were black and the median age was 20 years. There was no difference in median (interquartile range) LL-37 between the HIV-infected group and controls [58.3 (46.4,69.5) vs. 51.3 (40.8,98.2) ng/ml, respectively; p=0.57]; however, the ART-experienced group had higher concentrations than the ART-naive group [66.2 (55.4,77.0) vs. 48.9 (38.9,57.9) ng/ml, respectively; p<0.001]. LL-37 was positively correlated with 25(OH)D in controls, but not in HIV-infected groups, and was positively correlated with current CD4 and ΔCD4 (current-nadir) in the ART-experienced group. After adjustment for age, race, sex, and HIV duration, the association between LL-37 and CD4 remained significant. These findings suggest that HIV and/or HIV-related variables may alter the expected positive relationship between vitamin D and LL-37 and should be further investigated.

Effects of combination antiretroviral therapies on the risk of myocardial infarction among HIV patients

BACKGROUND

Cohort studies have demonstrated greater risk of myocardial infarction (MI) associated with specific antiretroviral use, while meta-analyses of randomized controlled trials (RCTs) have not. These differences may be due to inherent biases in the observational study design or to the limited duration of randomized trials. We conducted a new-user, active-comparator cohort study emulating an RCT comparing the initiation of several antiretrovirals as part of combination antiretroviral therapy (cART) and MI.

METHODS

We included North Carolina (NC) Medicaid beneficiaries infected with human immunodeficiency virus between 2002 and 2008 who were previously untreated with cART. We compared hazard ratios (HRs) and 95% confidence intervals (CIs) of MI between abacavir and tenofovir recipients, and lopinavir-ritonavir or atazanavir recipients and nonnucleoside reverse transcriptase inhibitor (NNRTI) recipients. We adjusted for confounding through inverse probability weighting methods.

RESULTS

There were 3481 NC Medicaid new cART recipients who contributed 6399 person-years and experienced 38 MI events. Receiving abacavir compared with tenofovir as part of cART was associated with an increased rate of MI (unadjusted HR = 2.70 [95% CI = 1.24-5.91]; adjusted HR = 2.05 [0.72-5.86]). Point estimates also suggest a relationship between receipt of atazanavir or lopinavir-ritonavir compared with an NNRTI and MI, although estimates were imprecise.

CONCLUSIONS

We found an increased rate of MI among patients initiating abacavir compared with tenofovir, although the association was decreased after confounding adjustment. Without a very large prospective comparative clinical trial, a much larger observational study of patients initiating cART would be needed to better define this apparent association.

Optimal diagnostic measures and thresholds for hypogonadism in men with HIV/AIDS: comparison between 2 transdermal testosterone replacement therapy gels

OBJECTIVES

To determine the incidence of hypogonadism in men with human immunodeficiency virus (HIV)/acquired immunodeficiency virus (AIDS), the most useful serum testosterone measurement and threshold for diagnosing hypogonadism, and the comparative efficacy of 2 testosterone replacement therapy (TRT) 1% gels (AndroGel® [Abbott Laboratories] and Testim® [Auxilium Pharmaceuticals, Inc.]).

DESIGN AND SUBJECTS

This was a 2-stage observational study. In stage 1, patient records from 2 medical practices specializing in HIV/AIDS were reviewed. Eligible patients were aged ≥ 18 years; had HIV-seropositive status confirmed by enzyme-linked immunosorbent assay and western blot test or HIV-1 viremia confirmed by HIV-1 RNA polymerase chain reaction; and had prior baseline testosterone assessments for hypogonadism (ie, presence of signs/symptoms of hypogonadism as well as total testosterone [TT] and free testosterone [FT] level measurements). Stage 2 included the evaluation of patients from stage 1 who were treated with 5 to 10 g/day of TRT. The stage 2 inclusion criteria were a diagnosis of low testosterone (defined as TT level < 300 ng/dL and/or FT level < 50 pg/mL, as per The Endocrine Society guidelines and presence/absence of hypogonadal signs and symptoms); ≥ 12 months of evaluable sign and symptom assessments and TT/FT level measurements while on TRT with either Testim® or AndroGel®; and ≥ 4 weeks on initial TRT if the initial TRT was switched or discontinued.

RESULTS

Four hundred one of 422 patients met the stage 1 inclusion criteria and 167 of 401 patients (AndroGel®, n = 92; Testim®, n = 75) met the stage 2 inclusion criteria. Total testosterone level < 300 ng/dL alone identified 24% (94 of 390) of patients as hypogonadal, but failed to diagnose an additional 111 patients (67.7%) with FT levels < 100 pg/mL and hypogonadal symptoms. Through month 12, AndroGel® increased mean TT levels by +42.8% and FT levels by +66.9%, compared with +178.7% (P = 0.017) and +191% (P = 0.039), respectively, for Testim®. Patients treated with Testim® showed significantly greater improvements in libido, sexual performance, nighttime energy, focus/concentration, and abdominal girth, and trends for greater improvement in fatigue and erectile dysfunction than patients treated with AndroGel®. No patients discontinued therapy due to adverse events.

CONCLUSION

The most useful serum testosterone measurement and threshold for diagnosing hypogonadism in men with HIV/AIDS was FT level < 100 pg/mL, which identified 64% of men as hypogonadal with the presence of ≥ 1 hypogonadal symptom. This is above currently accepted thresholds. Criteria using TT level < 300 ng/dL and FT level < 50 pg/mL only diagnosed 24% and 19% of patients, respectively, as having hypogonadism. Testim® was more effective than AndroGel® in increasing TT and FT levels and improving hypogonadal symptoms.

Assessment of biomarkers of cardiovascular risk among HIV type 1-infected adolescents: role of soluble vascular cell adhesion molecule as an early indicator of endothelial inflammation

Cardiovascular disease (CVD) biomarkers were examined in a cohort of HIV-infected and HIV-uninfected adolescents who participated in Adolescent Trials Network study 083 utilizing samples from the Reaching for Excellence in Adolescent Care cohort, a longitudinal study of youth infected through adult risk behavior. Nonfasting blood samples from 97 HIV-infected and 81 HIV-uninfected adolescents infected by adult risk behaviors were analyzed for total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), very low-density lipoprotein (VLDL), triglycerides, apolipoprotein A-I, high-sensitivity C-reactive protein (hsCRP), soluble vascular adhesion molecule-1 (sVCAM-1), myeloperoxidase, and neopterin at baseline and 18 months later. Results were analyzed using ANOVA, Wilcoxon signed-rank, and paired t tests. Among infected subjects 67 received antiretroviral therapy and 30 were treatment naive. The HIV-infected and HIV-uninfected subjects were similar in gender, ethnicity, and cardiovascular risk factors such as smoking and obesity. In all groups lipid parameters were within accepted guidelines for cardiovascular risk. Among HIV-infected youth on antiretroviral therapy (ART), HDL and apoprotein A-I were significantly lower when compared to uninfected youth. hsCRP was not elevated and thus not predictive for risk in any group. sVCAM-1 levels were significantly elevated in both HIV-infected groups: 1,435 ng/ml and 1,492 ng/ml in untreated and treated subjects, respectively, and 1,064 ng/ml in the uninfected group (p<0.0001). Across all groups neopterin correlated with sVCAM at 18 months (Spearman correlation coefficient 0.58, p<0.0001). Only 9% of ART-treated subjects fully suppressed virus. Lipid profiles and hsCRP, traditional markers of cardiovascular disease, are not abnormal among HIV-infected youth but elevated sVCAM may be an early marker of atherosclerosis.

Short communication: from wasting to obesity: initial antiretroviral therapy and weight gain in HIV-infected persons

Data on weight gain and the progression to overweight/obesity in HIV-infected persons during initial combination antiretroviral therapy (cART) are limited, and comparisons to the general population are inconclusive. Weight and body mass index (BMI) changes were studied in HIV-infected adults who remained on initial cART for 12 consecutive months and in an HIV-uninfected cohort receiving care at Duke University Medical Center between 1998 and 2008. Overweight/obesity was defined as BMI ≥25 kg/m(2). Variables were analyzed by Chi-square and Student's t-tests. Ninety-two HIV-infected persons (median age 38.2 years) met inclusion criteria. Weight and BMI increased during 12 months of cART (80.0 to 84.4 kg, p<0.0001; 26.4 to 27.9 kg/m(2), p<0.0001; respectively). Weight gain was greater in HIV-infected females compared to males (8.6 vs. 3.6 kg, p=0.04), in persons treated with protease inhibitor (PI)-based cART compared to non-PI-based cART (9.0 vs. 2.7 kg, p=0.001), and in persons with a pretreatment CD4 count <200 cells/mm(3) compared to ≥200 cells/mm(3) (8.9 vs. 0.3 kg, p<0.0001). Overweight/obesity prevalence increased from 52% to 66% during 12 months of initial cART, a 27% relative increase (p=0.002). HIV-infected persons had a lower prevalence of pretreatment overweight/obesity compared to 94 age-matched control subjects (52% vs. 91%, p<0.001); however, there was no change in weight (92.7 vs. 93.0 kg, p=0.5) or overweight/obesity prevalence (91% to 92%, p>0.9) during 12 months in the control cohort. Management should anticipate excess weight gain during the first year of cART in persons who are female, have a pretreatment CD4 <200 cells/mm(3), or will initiate PI-based cART.

HIV-specific immune dysregulation and atherosclerosis

HIV + patients face a heightened risk of cardiovascular disease (CVD), which cannot be fully explained by traditional risk factors or antiretroviral therapy (ART)-related cardiotoxicity. Increasing evidence suggests a significant contribution of HIV-specific immune dysregulation to atherosclerosis. HIV-specific immune dysregulation may have the following atherogenic effects: 1) activation of endothelial and immune cells; 2) enhancement of the percentage of circulating atherogenic immune cell subsets; and 3) modification of lipid function. Efforts are underway to link immune dysregulation markers with validated CVD endpoints and to identify genetic predispositions for HIV-induced atherogenesis. Moreover, immune suppressants are under evaluation in HIV + patients to attempt modification of immune-mediated CVD risk. Taken together, these studies will enhance understanding of CVD risk stratification and reduction strategies in HIV.

A role for mucosal IL-22 production and Th22 cells in HIV-associated mucosal immunopathogenesis

Interleukin-22 (IL-22) is a cytokine with epithelial reparative and regenerative properties that is produced by Th22 cells and by other immune cell subsets. Therefore, we explored the hypothesis that disruption of the gut barrier during HIV infection involves dysregulation of these cells in the gastrointestinal mucosa. Sigmoid IL-22-producing T cell and Th22 cells were dramatically depleted during chronic HIV infection, epithelial integrity was compromised, and microbial translocation was increased. These alterations were reversed after long-term antiretroviral therapy. While all mucosal IL-22-producing T-cell subsets were also depleted very early during HIV infection, at these early stages IL-22 production by non-T-cell populations (including NKp44+ cells) was increased and gut epithelial integrity was maintained. Circulating Th22 cells expressed a higher level of the HIV co-receptor/binding molecules CCR5 and α4β7 than CD4+ T-cell subsets in HIV-uninfected participants, but this was not the case after HIV infection. Finally, recombinant IL-22 was protective against HIV and tumor necrosis factor-α-induced gut epithelial damage in a validated in vitro gut epithelial system. We conclude that reduced IL-22 production and Th22 depletion in the gut mucosa are important factors in HIV mucosal immunopathogenesis.

The National NeuroAIDS Tissue Consortium brain gene array: two types of HIV-associated neurocognitive impairment

Background

The National NeuroAIDS Tissue Consortium (NNTC) performed a brain gene expression array to elucidate pathophysiologies of Human Immunodeficiency Virus type 1 (HIV-1)-associated neurocognitive disorders.

Methods

Twenty-four human subjects in four groups were examined A) Uninfected controls; B) HIV-1 infected subjects with no substantial neurocognitive impairment (NCI); C) Infected with substantial NCI without HIV encephalitis (HIVE); D) Infected with substantial NCI and HIVE. RNA from neocortex, white matter, and neostriatum was processed with the Affymetrix® array platform.

Results

With HIVE the HIV-1 RNA load in brain tissue was three log₁₀ units higher than other groups and over 1,900 gene probes were regulated. Interferon response genes (IFRGs), antigen presentation, complement components and CD163 antigen were strongly upregulated. In frontal neocortex downregulated neuronal pathways strongly dominated in HIVE, including GABA receptors, glutamate signaling, synaptic potentiation, axon guidance, clathrin-mediated endocytosis and 14-3-3 protein. Expression was completely different in neuropsychologically impaired subjects without HIVE. They had low brain HIV-1 loads, weak brain immune responses, lacked neuronally expressed changes in neocortex and exhibited upregulation of endothelial cell type transcripts. HIV-1-infected subjects with normal neuropsychological test results had upregulation of neuronal transcripts involved in synaptic transmission of neostriatal circuits.

Interpretation

Two patterns of brain gene expression suggest that more than one pathophysiological process occurs in HIV-1-associated neurocognitive impairment. Expression in HIVE suggests that lowering brain HIV-1 replication might improve NCI, whereas NCI without HIVE may not respond in kind; array results suggest that modulation of transvascular signaling is a potentially promising approach. Striking brain regional differences highlighted the likely importance of circuit level disturbances in HIV/AIDS. In subjects without impairment regulation of genes that drive neostriatal synaptic plasticity reflects adaptation. The array provides an infusion of public resources including brain samples, clinicopathological data and correlative gene expression data for further exploration (http://www.nntc.org/gene-array-project).

Longitudinal assessment of cardiac diastolic function in HIV-infected patients

Asymptomatic isolated diastolic dysfunction (DD), with normal left ventricular systolic function, may be the first indication of underlying cardiac disease in HIV-negative populations. We previously reported a high prevalence (37%) of DD among asymptomatic HIV-infected patients at low risk for AIDS and cardiovascular disease (CVD). We performed a longitudinal assessment of interval echocardiographic changes in this cohort over a four-year period. Repeat transthoracic echocardiograms (TTEs) utilized standard techniques. Sixty (of the original 91) HIV-infected patients, predominately men, underwent repeat TTE (median follow-up 3.7 years, interquartile range [IQR] 3.5, 4.0). Cohort characteristics (median; IQR) include age 42.0 (36.5, 46.0) years, HIV duration 16.4 years (8.1, 18.9), current CD4 count 572.0 cells/mm(3) (436.5, 839.0), antiretroviral therapy (ART) duration 8.1 years (4.8, 13.4) and Framingham risk score 1.0 (0.0, 2.0). DD was observed in 28/60 patients on re-evaluation (47%, 95% confidence interval [CI] 34%, 60%); 31% (11/36) of patients had new onset DD for an overall incidence of 8.2/100 person-years. On follow-up, subjects with DD were older, had a trend towards higher body mass index, hypertension and longer duration of HIV infection compared with subjects without DD. We confirmed a high prevalence of DD (47%) in asymptomatic HIV-infected patients at low risk for AIDS and CVD.

Bone effects of rosiglitazone in HIV-infected patients with lipoatrophy

OBJECTIVES

Thiazoledinediones increase limb fat in HIV+ patients with lipoatrophy. However, their use in the general population has been associated with bone loss and fracture. We sought to determine the effects of rosiglitazone on bone metabolism in HIV-infected patients.

METHODS

HIV+ patients with lipoatrophy were randomized to rosiglitazone versus placebo for 48 weeks in a double-blind, placebo-controlled trial. Limb fat, bone mineral density (BMD), bone formation markers (procollagen type 1 amino-terminal propeptide [P1NP], osteocalcin [OC]) and bone resorption markers (C-terminal telopeptide of type I collagen [CTX]) were measured, along with receptor activator for nuclear factor kappa β ligand (RANKL), osteoprotegerin (OPG), and inflammatory cytokines.

RESULTS

Seventy-one subjects were randomized to rosiglitazone or placebo: 17% female and 51% white. Total BMD did not change significantly in either group. In the rosiglitazone group, P1NP showed statistically significant decreases at 24 and 48 weeks; however, changes compared to placebo were only significant at 24 weeks. OC decreased significantly in the rosiglitazone group at 24 weeks, but there were no between-group differences. CTX, RANKL, or OPG did not change for either group. Multivariable regression within the rosiglitazone arm showed P1NP changes were inversely associated with limb fat changes, protease inhibitors, and tenofovir use.

CONCLUSION

Rosiglitazone use was associated with decreased bone formation, but it did not alter bone resorption or total BMD. The increase in limb fat that accompanies rosiglitazone use appears to be associated with decreased osteoblast activity. Further studies are needed to determine the effect of thiazoledinediones on bone health in HIV-infected persons.

Asymmetric dimethylarginine concentrations decrease in patients with HIV infection under antiretroviral therapy

BACKGROUND

In HIV-infected patients, elevated plasma concentrations of the endogenous nitric oxide synthase inhibitor and cardiovascular risk factor asymmetric dimethylarginine (ADMA) are documented, and levels correlate with markers of immune activation, such as neopterin.

METHODS

In this study, the effect of antiretroviral therapy (ART) on arginine, ADMA and symmetric dimethylarginine (SDMA) levels was investigated and related to changes of immune activation markers and lipids. Concentrations of ADMA, SDMA, arginine, C-reactive protein (CRP) and neopterin were determined in 112 HIV-infected patients after 12 months of successful ART, as reflected by undetectable HIV RNA levels, and compared to baseline levels. ADMA, SDMA, arginine and urine neopterin levels were determined by HPLC, and plasma neopterin concentrations by ELISA. Disease activity before and after treatment was monitored by determination of HIV RNA levels and CD4(+) T-cell counts. Lipids and CRP were determined by routine laboratory assays.

RESULTS

Under treatment with ART, concentrations of ADMA, SDMA and arginine dropped in parallel with decreasing HIV RNA levels and neopterin concentrations, while cholesterol, triglyceride levels and CD4(+) T-cell counts increased. CRP levels did not change. After ART, a significant inverse association between ADMA and plasma cholesterol was observed.

CONCLUSIONS

Successful ART, defined by HIV RNA levels below the limit of detection, leads to decreasing levels of methylated arginines and immune activation markers. Thus, it is unlikely that disturbances of dimethylarginine metabolism account for the increased risk of cardiovascular events of HIV-infected patients under ART.

Inflammation markers after randomization to abacavir/lamivudine or tenofovir/emtricitabine with efavirenz or atazanavir/ritonavir

BACKGROUND

The effect of specific antiretrovirals on inflammation is unclear.

METHODS

A5224s was a substudy of A5202, which randomized HIV-infected treatment-naïve patients to blinded abacavir/lamivudine (ABC/3TC) or tenofovir/emtricitabine (TDF/FTC) with open-label efavirenz (EFV) or atazanavir/ritonavir (ATV/r) in a factorial design. Our analysis compared changes in inflammation markers from baseline to week 24 between ABC/3TC and TDF/FTC. Secondary analyses included changes at week 96 and comparisons of EFV vs. ATV/r.

RESULTS

Analyses included 244 patients (85% male, 48% white non-Hispanic), median age 39 years, HIV-1 RNA 4.6 log10 copies/ml, CD4 240 cells/μl. TNF-α, soluble receptors of TNF-α (sTNFR)-I and II, soluble vascular cellular adhesion molecule (sVCAM)-1 and soluble intercellular adhesion molecule (sICAM)-1 decreased significantly at weeks 24 and 96, without significant differences between components (P ≥ 0.44). At week 24, ABC/3TC had a greater high-sensitivity C-reactive protein (hsCRP) mean fold change than TDF/FTC {1.43 vs. 0.88, estimated mean fold change percentage difference [Δ] 61.5% [95% confidence interval (CI) 13.6%, 129.5%]; P = 0.008}. Similar results were seen at week 96 (P = 0.021). At week 24 (but not 96), EFV had a greater hsCRP mean fold change than ATV/r [1.41 vs. 0.88; Δ = 60.2% (12.6%, 127.7%); P = 0.009]. IL-6 decreased significantly at week 24 with TDF/FTC but not with ABC/3TC (between-components P = 0.019). At week 96, IL-6 decreased significantly in both nucleoside reverse transcriptase inhibitor components (between-components P = 0.11). IL-6 changes were not significantly different between ATV/r and EFV at either time point (P ≥ 0.89).

CONCLUSIONS

Soluble TNF-receptors and adhesion molecules decreased following treatment initiation and did not differ by regimens. Differences were seen on hsCRP and IL-6 changes with ABC/3TC vs. TDF/FTC and on hsCRP with EFV vs. ATV/r.

Omega-3 fatty acids do not improve endothelial function in virologically suppressed HIV-infected men: a randomized placebo-controlled trial

Omega-3 fatty acids decrease cardiovascular disease (CVD) mortality possibly due to antiinflammatory effect. Inflammation and endothelial dysfunction likely play a role in the heightened CVD risk in HIV. Our goal was to evaluate the effect of omega-3 fatty acids primarily on endothelial function and inflammation in HIV-infected adults with moderate CVD risk on stable antiretroviral therapy. We conducted a 24-week, randomized, double-blind, placebo-controlled study to evaluate the effect of omega-3-acid ethyl esters 1 g twice a day. Flow-mediated dilation (FMD) of the brachial artery, lipoproteins and markers of inflammation, endothelial activation, coagulation, and insulin resistance were measured at entry and week 24. There were no within- or between-group differences in change in FMD over 24 weeks (mean change in FMD -0.13% vs. 1.5% for treatment vs. placebo; p=0.21). There were no between-group differences in changes in lipoprotein levels or biomarkers tested, except soluble tumor necrosis factor receptor-I, which favored omega-3-acid ethyl esters. Omega-3 fatty acids did not improve endothelial function or activation, coagulation, or insulin resistance in virologically suppressed, HIV-infected men with moderate CVD risk; however, inflammation tended to improve. This suggests that omega-3 fatty acids may not be potent enough to counteract the enhanced inflammation and endothelial dysfunction due to HIV and antiretrovirals.

Overall benefit of antiretroviral treatment on the risk of fracture in HIV: nested case-control analysis in a health-insured population

OBJECTIVES

Fractures are common and associated with multiple risk factors. We assessed the risks of fracture associated with time-dependent, differential antiretroviral drug exposures among a cohort of persons with HIV infection.

DESIGN

Nested case-control study from an HIV cohort of 59,594 medically insured persons with HIV infection enrolled in a medical care between January 1997 and March 2008.

METHODS

Cases were participants with a low-impact, nontraumatic fracture identified by ICD-9-CM codes; noncases were 1:4 matched and without fracture.

RESULTS

Cases included 2,477 persons with HIV infection with fractures, who were risk-set matched to 9,144 persons with HIV infection without fractures. Exposure to antiretroviral therapy by drug class and by duration (any drug/class) was associated with reduced risk for fracture. Drug-specific antiretroviral exposures over time identified an increased risk for fracture associated with darunavir, delavirdine and saquinavir, whereas reduced risk was associated with efavirenz, emtricitabine, lamivudine, tenofovir, and zidovudine. An initial null risk became a reduced risk with increased duration for nevirapine. In a similar pattern, abacavir, didanosine, nelfinavir, ritonavir and stavudine were initially associated with increased risk for fracture, after which the risk became null with increased duration of exposure. Null or uncertain risk for fracture was associated with amprenavir, atazanavir, enfuvirtide, fosamprenavir, indinavir, lopinavir, tipranavir, and zalcitabine.

CONCLUSION

Our findings suggest an overall reduced risk for facture in persons treated versus not treated with antiretroviral drugs for HIV infection. Differential drug-specific exposure-response relationships for fracture will need to be further evaluated in other study populations.

Retinal vessel caliber among people with acquired immunodeficiency syndrome: relationships with disease-associated factors and mortality

PURPOSE

To evaluate relationships between retinal vessel caliber, AIDS-related factors, and mortality.

DESIGN

Longitudinal, observational cohort study.

METHODS

We evaluated data for participants without ocular opportunistic infections at initial examination (baseline) in the Longitudinal Studies of the Ocular Complications of AIDS (1998-2008). Semi-automated evaluation of fundus photographs (1 eye/participant) determined central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), and arteriole-to-venule ratio (AVR) at baseline. Multiple linear regression models, using forward selection, identified independent relationships between indices and various host- and disease-related variables.

RESULTS

Included were 1250 participants. Mean follow-up for determination of mortality was 6.1 years. Smaller CRAE was related to increased age (P < .001) and hypertension (P < .001); larger CRAE was related to lower hematocrit (P = .002). Larger CRAE and CRVE were associated with black race (P < .001). Larger CRVE was related to smoking (P = .004); smaller CRVE was related to age (P < .001) and higher mean corpuscular volume (P = .001). We observed the following relationships with AIDS-associated factors: smaller CRAE and larger CRVE with history of highly active antiretroviral therapy (HAART; P < .001); and larger CRAE with lower CD4+ T lymphocyte count (P = .04). We did not identify independent relationships with human immunodeficiency virus RNA blood levels. There was a 12% (95% CI, 2%-21%) increase in mortality risk per quartile of decreasing AVR (P = .02).

CONCLUSIONS

Variations in retinal vascular caliber are associated with AIDS-specific factors and are markers for increased mortality risk. Relationships are consistent with the hypothesis that the vasculature is altered by known atherogenic effects of chronic HAART or the prolonged inflammatory state associated with AIDS.

Vitamin D supplementation and endothelial function in vitamin D deficient HIV-infected patients: a randomized placebo-controlled trial

BACKGROUND

Studies suggest that vitamin D deficiency is a risk factor for cardiovascular disease and diabetes. Vitamin D deficiency is prevalent in HIV patients but the effect of vitamin D supplementation on cardiovascular risk in this population is unknown.

METHODS

We conducted a randomized, double-blind, placebo-controlled trial among 45 HIV-infected adults in Cleveland (OH, USA) on stable antiretroviral therapy with durable virological suppression and a baseline serum 25-hydroxyvitamin D level of ≤20 ng/ml. Participants were randomized 2:1 to vitamin D3 4,000 IU daily or placebo for 12 weeks. The primary outcome was a change in flow-mediated brachial artery dilation (FMD).

RESULTS

Baseline demographics were similar except for age (vitamin D versus placebo, mean ±sd 47 ±8 versus 40 ±10 years; P=0.009). Both groups had reduced FMD at baseline (median values 2.9% [IQR 1.6-4.8] for vitamin D versus 2.5% [IQR 1.7-6.4] for placebo; P=0.819). Despite an increase in the concentration of serum 25-hydroxyvitamin D from baseline to 12 weeks (5.0 ng/ml [IQR -0.9-7.4] versus -1.9 ng/ml [IQR -4.0-0.1] for vitamin D versus placebo, respectively; P=0.003), there was no difference in FMD change (0.55% [IQR -1.05-2.13] versus 0.29% [IQR -1.61-1.77]; P=0.748). Vitamin D supplementation was associated with a decrease in total and non-high-density lipoprotein cholesterol, and an increase in indices of insulin resistance.

CONCLUSIONS

Among HIV-infected individuals with vitamin D deficiency, supplementation with 4,000 IU vitamin D3 daily for 12 weeks modestly improved vitamin D status and cholesterol but worsened insulin resistance without change in endothelial function. The mechanisms of resistance to standard doses of vitamin D and the complex role of vitamin D in glucose metabolism in this population require further investigation.

Predictors of limb fat gain in HIV positive patients following a change to tenofovir-emtricitabine or abacavir-lamivudine

BACKGROUND

Antiretroviral treatment (cART) in HIV causes lipoatrophy. We examined predictors of anthropometric outcomes over 96 weeks in HIV-infected, lipoatrophic adults receiving stable cART randomised to tenofovir-emtricitabine (TDF-FTC) or abacavir-lamivudine (ABC-3TC) fixed dose combinations.

METHODOLOGY/PRINCIPAL FINDINGS

The STEAL study was a prospective trial of virologically suppressed participants randomised to either TDF-FTC (n = 178) or ABC-3TC (n = 179). Anthropometric assessment was conducted at baseline, weeks 48 and 96. The analysis population included those with baseline and week 96 data remaining on randomised therapy. Distribution of limb fat change was divided into four categories (≤ 0%, >0-10%, >10-20%, >20%). Baseline characteristics [demographics, medical history, metabolic and cardiovascular biomarkers] were assessed as potential predictors of change in percent subcutaneous limb fat using linear regression. 303 participants (85% of STEAL population) were included. Baseline characteristics were: mean (± SD) age 45 (± 8) years; thymidine analogue nucleoside reverse transcriptase inhibitor (tNRTI) duration 4 (± 3) years; limb fat 5.4 (± 3.0)kg; body mass index 24.7 (± 3 .5) kg/m(2). Mean (SD) limb fat gain to week 48 and 96 was 7.6% (± 22.4) and 13.2% (± 27.3), respectively, with no significant difference between groups. 51.5% of all participants had >10% gain in limb fat. Predictors of greater limb fat gain at week 96 were baseline tNRTI (10.3, p = 0.001), glucose >6 mmol/L (16.1, p = 0.04), higher interleukin 6 (IL-6) (2.8, p = 0.004) and lower baseline limb fat (3.8-6.4 kg - 11.2; >6.4 kg - 15.7, p trend<0.001).

CONCLUSIONS/SIGNIFICANCE

Modest peripheral fat gain occurred with both TDF-FTC and ABC-3TC. Baseline factors associated with more severe lipodystrophy (lipoatrophy, baseline tNRTI, raised IL6, and glucose) predicted greater limb fat recovery at 96 weeks.

Vitamin D is linked to carotid intima-media thickness and immune reconstitution in HIV-positive individuals

BACKGROUND

Patients with HIV infection are at increased risk of cardiovascular disease (CVD). Vitamin D insufficiency has been associated with increased CVD risk in non-HIV populations. This study sought to determine the relationship between vitamin D status and markers of CVD and HIV-related factors in HIV-positive patients.

METHODS

Patients with HIV infection on antiretroviral therapy and healthy controls were prospectively enrolled. Fasting lipids, glucose, insulin, inflammatory markers (soluble tumour necrosis factor-α receptor I, interleukin-6 and high-sensitivity C-reactive protein) and endothelial markers (soluble intercellular adhesion molecule-1 and soluble vascular cell adhesion molecule-1) were measured. Fasting 25-hydroxyvitamin D (25(OH)D) was measured from stored serum samples. The internal carotid artery and common carotid artery (CCA) intima-media thickness (IMT) were measured in a subset of HIV-positive patients. Baseline cross-sectional data were analysed.

RESULTS

A total of 149 HIV-positive patients (56 with carotid IMT) and 34 controls were included. Controls had higher adjusted mean 25(OH)D levels than HIV-positive patients (P=0.02). In multivariable linear regression among the HIV-positive patients, 25(OH)D was positively associated with CD4(+) T-cell restoration after antiretroviral therapy (ΔCD4 = current - nadir CD4(+) T-cell; P<0.01), but was not associated with inflammatory or endothelial markers. In multivariable logistic regression, odds of having CCA IMT above the median were more than 10× higher in those with lower 25(OH)D levels (OR=10.62, 95% CI 1.37-82.34; P<0.01).

CONCLUSIONS

Vitamin D status in HIV-positive patients was positively associated with improved immune restoration after antiretroviral therapy and negatively associated with CCA IMT. These findings suggest that vitamin D may play a role in HIV-related CVD and in immune reconstitution after antiretroviral therapy.

Abacavir use and risk of acute myocardial infarction and cerebrovascular events in the highly active antiretroviral therapy era

BACKGROUND

Some studies have suggested that exposure to antiretroviral therapy (ART) with abacavir is associated with an increased risk of acute myocardial infarction (AMI).

METHODS

Using the Veterans Health Administration's Clinical Case Registry we calculated the risk of AMI and cerebrovascular events (CVA) associated with the cumulative use of abacavir and other nucleoside combinations. We also evaluated the impact of pre-existing chronic kidney disease on the selection of abacavir versus tenofovir in the last recorded ART regimen, and on highly active antiretroviral therapy-associated AMI and CVA risks.

RESULTS

A total of 19,424 human immunodeficiency virus-infected patients contributed 76,376 patient-years of follow. After adjusting for age, hypercholesterolemia, hypertension, type 2 diabetes, and smoking, the hazard ratio (HR) for each year of abacavir use was 1.18 (95% confidence interval [CI], .92-1.50; P=.191) for AMI and 1.16 (95% CI, .98-1.37; P=.096) for CVA. Abacavir use was more common among patients with prior chronic kidney disease than was tenofovir use (12.46% versus 7.15%; P=.0001), and chronic kidney disease was associated with a significantly higher risk of AMI (HR, 2.41; 95% CI, 1.73-3.36), and CVA (HR, 1.80; 95% CI, 1.44-2.24). Compared with patients who received neither tenofovir nor abacavir, patients who received tenofovir had lower risk of AMI (HR, 0.16; 95% CI, .08-.33; P=.0001) and CVA (HR, 0.22; 95% CI, .15-.32; P=.001). Use of abacavir was associated with lower risk of CVA (HR, 0.60; 95% CI, .45-.79).

CONCLUSIONS

We observed no association between cumulative or current abacavir use and AMI or CVA. Abacavir use was more common than was tenofovir use among patients with prior chronic kidney disease, and chronic kidney disease independently predicted higher rates of AMI and CVA.

Hypertriglyceridemia, Metabolic Syndrome, and Cardiovascular Disease in HIV-Infected Patients: Effects of Antiretroviral Therapy and Adipose Tissue Distribution

The use of combination antiretroviral therapy (CART) in HIV-infected patients has resulted in a dramatic decline in AIDS-related mortality. However, mortality due to non-AIDS conditions, particularly cardiovascular disease (CVD) seems to increase in this population. CART has been associated with several metabolic risk factors, including insulin resistance, low HDL-cholesterol, hypertriglyceridemia and postprandial hyperlipidemia. In addition, HIV itself, as well as specific antiretroviral agents, may further increase cardiovascular risk by interfering with endothelial function. As the HIV population is aging, CVD may become an increasingly growing health problem in the future. Therefore, early diagnosis and treatment of cardiovascular risk factors is warranted in this population. This paper reviews the contribution of both, HIV infection and CART, to insulin resistance, postprandial hyperlipidemia and cardiovascular risk in HIV-infected patients. Strategies to reduce cardiovascular risk are also discussed.

HIV-Associated Venous Thromboembolism

HIV infection has been recognized as a prothrombotic condition and this association has now been proven by a large number of studies with a reported VTE frequency among HIV-infected patients ranging from 0.19% to 7,63 %/year. HIV infection is associated with a two to tenfold increased risk of venous thrombosis in comparison with a general population of the same age. Some risk factors demonstrated a strongest association with VTE such as, low CD4⁺ cell count especially in the presence of clinical AIDS, protein S deficiency, and protein C deficiency. Whereas other risk factors are still controversial like protease inhibitor therapy, presence of active opportunistic infections and presence of antiphospholipid antibodies, including anticardiolipin antibodies and lupus anticoagulant. Physicians caring for HIV positive patients should be able to recognize and treat not only the well-known opportunistic infections and malignancies associated with this chronic disease, but also be alert to the less well-known complications such as thromboses. Pulmonary embolism should be included in the differential diagnosis when patients with HIV/AIDS have unexplained dyspnea or hypoxemia. In younger individuals with VTE, especially men, without other identifiable risk factors for VTE, HIV should be considered. Because interactions between warfarin and antiretrovirals is possible, health care providers should also be alert to the potential of dangerously high or low INRs when they are giving anticoagulants to patients with HIV infection who are undergoing antiretroviral therapy.

Management of HIV infection in treatment-naive patients: a review of the most current recommendations

PURPOSE

The most current guidelines issued by the Department of Health and Human Services (DHHS) on the management of human immunodeficiency virus (HIV) infection in treatment-naive patients are reviewed.

SUMMARY

Treatment guidelines are updated frequently because of the emergence of data demonstrating the risks and benefits of antiretroviral therapy. The DHHS guidelines strongly recommend initiating therapy in patients with certain conditions regardless of CD4 cell count and in patients with CD4 cell counts of <350 cells/mm(3). Although supporting data are less definitive, treatment is also recommended for patients with CD4 cell counts of 350-500 cells/mm(3). Treatment for patients with CD4 cell counts of >500 cells/mm(3) is controversial. Although cumulative observational data and biological evidence support treatment at higher CD4 cell counts, randomized controlled trial data to support this are not available, and the risk of antiretroviral toxicities, resistance, non-adherence, and cost should be considered in individual patients. The preferred regimens have been consolidated to four options, including a dual-nucleoside reverse transcriptase inhibitor backbone (tenofovir plus emtricitabine) with a nonnucleoside reverse transcriptase inhibitor (efavirenz), a ritonavir-boosted protease inhibitor (atazanavir plus ritonavir or darunavir plus ritonavir), or an integrase strand-transfer inhibitor (raltegravir). Regimens are classified as alternative or acceptable when they have potential safety or efficacy concerns, have higher pill burdens, or require more-frequent administration compared with preferred regimens.

CONCLUSION

The DHHS 2011 guidelines advocate earlier antiretroviral therapy initiation than recommended in recent years, and preferred regimens have been refined to maximize efficacy, safety, and quality of life for treatment-naive HIV-infected patients.

Secondary complications and co-infections in the HIV-infected adolescent in the antiretroviral era

PURPOSE OF REVIEW

The number of HIV-infected adolescents is increasing dramatically. With combination antiretroviral therapy, they are expected to live well into adulthood. However, complications are emerging at a higher rate in the HIV-infected population compared to the general population. HIV-infected adolescents are also at a high risk of sexually transmitted co-infections. This article reviews the main secondary complications and co-infections in the HIV-infected adolescent.

RECENT FINDINGS

HIV-infected adolescents are at a high risk of sexually transmitted infections. A careful, age-appropriate and developmentally appropriate inquiry into the individual's sexual behavior to assess risk is paramount, in addition to regular screening at medical visits. Treating co-infections is not only important for HIV-infected individuals, but also limits HIV transmission to others. In addition, monitoring and addressing modifiable secondary risk factors for complications such as renal disease, osteopenia or osteoporosis, and cardiovascular disease are critical, well before the onset of clinically apparent disease. Using antiretroviral therapy to suppress viral replication and inflammation appears to be a promising strategy for decreasing secondary complication risk, and likely overshadows the toxicities associated with the long-term use of certain antiretrovirals.

SUMMARY

Assessing and addressing the risk of secondary complications and co-infections in the HIV-infected adolescent is crucial for optimal length and quality of life.

Carotid intima media thickness, inflammatory markers, and endothelial activation markers in HIV Patients with lipoatrophy increased at 48 weeks regardless of use of rosiglitazone or placebo

Rosiglitazone may be useful for the treatment of antiretroviral therapy-associated lipoatrophy, but an association with cardiovascular disease (CVD) has been questioned in diabetics. We evaluated rosiglitazone's effect on surrogate markers of CVD in HIV-infected individuals with lipoatrophy. HIV(+) patients with lipoatrophy on thymidine-sparing regimens were randomized to rosiglitazone vs. placebo for 48 weeks. We serially assessed carotid IMT, fasting metabolic profiles, tumor necrosis factor (TNF)-α, soluble receptors (sTNFRI and II), interleukin (IL)-6, high-sensitivity C-reactive protein (hsCRP), myeloperoxidase (MPO), and endothelial activation markers [von Willebrand factor (vWF), soluble intercellular cell adhesion molecules-1 (sICAM-1), and vascular cell adhesion molecules-1 (sVCAM-1)]. Seventy-one subjects enrolled: 17% were female and 51%were white. Baseline characteristics were similar between groups except for higher total cholesterol in the placebo group (p = 0.04). At 48 weeks, common carotid artery (CCA) IMT changed significantly (p ≤ 0.05) within but not between the groups (p = 0.36): the median (IQR) increase was 0.10 (0.05, 0.25) mm and 0.15 (0, 0.25) mm in the rosiglitazone and placebo groups, respectively. hsCRP, sTNFRI and II, sVCAM-1, and vWF changed significantly (p ≤ 0.02) within but not between groups. Total cholesterol increased significantly in the rosiglitazone group (p = 0.008). In our study of virologically controlled subjects with lipoatrophy, rosiglitazone did not independently increase carotid IMT, endothelial activation, and inflammatory cytokines.

Assessment and modification of cardiovascular disease risk in the HIV-infected individual

HIV-infected patients are living decades longer than before owing to combination antiretroviral therapy. However, complications are emerging in this population at rates higher than the general population, including cardiovascular disease (CVD). HIV-infected patients have many traditional risk factors that account for a significant part of their increased risk of CVD. However, HIV factors, including complications from antiretroviral therapy and increased inflammation associated with chronic HIV infection, also play a role. Clinicians need to be ever-vigilant to calculate and help attenuate any modifiable CVD risk factors for each HIV-infected individual.

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.

Premature onset of cardiovascular disease in HIV-infected individuals: the drugs and the virus

Life expectancy in HIV-infected individuals has been greatly enhanced through immunologic restoration and virologic suppression resulting from antiretroviral therapy. Current clinical HIV care in Western countries focuses on treatment of drug toxicities and prevention of comorbidities. These non-AIDS HIV-related comorbidities, such as cardiovascular disease, occur even in individuals with virologic suppression and manifest at an earlier age than when normally presenting in the general population. While traditional risk factors are present in many HIV-infected individuals who develop cardiovascular disease, the additional roles of HIV-related chronic inflammation and immune activation as well as chronic HIV viremia may be significant. This review provides current evidence for the contributions of the virus, in terms of both chronic viremia and its contribution via chronic low-level inflammation, immune activation, premature immune senescence and dyslipidemia, to the pathogenesis of HIV-related cardiovascular disease, and balances this against the propensity of specific antiretroviral therapies to cause cardiovascular disease, in particular through altered cholesterol metabolism.