Cross-sectional study of endothelial function in HIV-infected patients in Brazil

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.

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.

Trends and Clinical Characteristics of HIV and Cerebrovascular Disease in Low- and Middle-Income Countries (LMICs) Between 1990 and 2021

PURPOSE OF THE REVIEW

To describe trends and clinical characteristics of HIV and cerebrovascular disease between 1990 and 2021 in LMICs and identify the gaps in our understanding.

RECENT FINDINGS

In the era of antiretroviral therapy (ART), people living with HIV (PLWH) live longer and risk excess cerebrovascular events due to ageing and HIV-driven factors. Despite the highest burden of HIV infection in low-to-middle income countries, there is underreporting in the literature of cerebrovascular events in this population. We systematically reviewed published literature for primary clinical studies in adult PLWH and cerebrovascular disease in LMICs. The clinical phenotype of cerebrovascular disease among PLWH over the last three decades in LMICs has evolved and transitioned to an older group with overlapping cerebrovascular risk factors. There is an important need to increase research in this population and standardise reporting to facilitate understanding, guide development of appropriate interventions, and evaluate their impact.

Cytomegalovirus may influence vascular endothelial health in Indonesian HIV-infected patients after 5 years on ART

Objectives

Accelerated atherosclerosis in older HIV-infected patients has been attributed to persistent immune activation and high burden cytomegalovirus (CMV), as demonstrated in transplant recipients and the general population. Here we assess CMV and inflammatory markers linked with vascular health in young adult patients treated in Indonesia.

Study design

HIV-infected adults (n = 32) were examined when they began antiretroviral therapy (ART) with < 200 CD4 T-cells/µl (V0) and after 60 months (V60). Age-matched healthy controls (HC, n = 32) were assessed once.

Methods

Flow Mediated Dilatation (FMD) was assessed by ultrasound on brachial arteries at V60 and in HC. Plasma markers of immune activation and endothelial activation, and CMV antibodies (lysate, gB, IE-1) were assessed in all samples. Results were assessed using bivariate (non-parametric) and multivariable analyses.

Results

Levels of inflammatory biomarkers and CMV antibodies declined on ART, but the antibodies remained higher than in HC. FMD values were similar in patients and HC at V60. In HIV patients, levels of CMV lysate antibody correlated inversely (r = − 0.37) with FMD. The optimal model predicting lower FMD values (adjusted R² = 0.214, p = 0.012) included CMV lysate antibodies and chondroitin sulphate. In HC, levels of sTNFR correlated inversely with FMD (r = − 0.41) and remained as a risk factor in the optimal multivariable model, with CMV glycoprotein-B (gB) antibody predicting a healthier FMD (adjusted R² = 0.248, p = 0.013).

Conclusions

Higher levels CMV antibodies optimally predict vascular health measured by FMD in HIV patients. However in healthy controls, sTNFR marks risk and CMV gB antibody may be protective.

Near-infrared spectroscopy-derived muscle oxygen saturation during exercise recovery and flow-mediated dilation are impaired in HIV-infected patients

Highly active antiretroviral therapy has been associated with the presence of endothelial dysfunction in HIV-infected patients, which may impair oxygen delivery to muscles during exercise and exercise recovery. Near-infrared spectroscopy (NIRS) has been used to assess muscle oxygen saturation (SmO₂) kinetics during exercise in different clinical populations in order to evaluate the balance between oxygen delivery and utilization by muscles. However, studies assessing SmO₂ in HIV-infected patients have not been conducted. Therefore, the aim of the study was to evaluate NIRS-derived SmO₂ during rhythmic handgrip exercise and flow-mediated dilation (FMD) in HIV-infected patients (HIV) compared to non-HIV-infected controls (N-HIV). Eighteen HIV and 17 N-HIV individuals underwent FMD assessment by ultrasound. The subjects then performed one set of rhythmic handgrip exercise until fatigue at 30% maximal isometric voluntary contraction. SmO₂ was measured during entire exercise and 2-min exercise 3recovery. Muscle oxygen resaturation rate (upslope of the SmO₂ over 10 s of recovery) was calculated. A significant lower FMD (3.5 ± 1.7 vs 5.9 ± 1.5%, P < 0.001) and slower oxygen resaturation rate (0.78 ± 0.4 vs 1.14 ± 0.4%·s^-1, P = 0.020) in HIV as compared to N-HIV group were observed. In conclusion, our findings demonstrated that HIV-infected patients had reduced FMD and impaired muscle oxygenation during exercise recovery compared to non-HIV individuals.

HIV infection, antiretroviral therapy, and measures of endothelial function, inflammation, metabolism, and oxidative stress

Background

HIV-infected patients have an increased risk of cardiovascular disease (CVD). Impaired endothelial function is an early risk factor for CVD in the general population. It is presumed that HIV infection is associated with impaired endothelial function, but results have been inconsistent.

Objectives

Our objectives were to determine the relationships between HIV infection, virologic suppression with antiretroviral therapy (ART), in vivo measures of conduit artery and microvascular endothelial function, and circulating biomarkers of pathways associated with CVD.

Methods

We performed a cross-sectional analysis of three prospectively enrolled groups from a single center: 28 were HIV-infected and virologically-suppressed on a regimen of FTC/TDF/EFV (HIV+ART+), 44 were HIV-infected but not on ART (HIV+ART-), and 39 were HIV-uninfected healthy volunteers (HIV-) matched to the HIV+ART- group for age, sex, smoking status, and height. None had diabetes, uncontrolled hypertension, known CVD, or other pro-inflammatory condition. Flow mediated dilation (FMD), nitroglycerin-mediated dilation (NTGMD), reactive hyperemia velocity time integral (RHVTI), and FMD/RHVTI of the brachial artery were measured, as well as circulating biomarkers of systemic inflammation, metabolism, oxidative stress, and endothelial activation.

Results

No significant differences were found amongst the three groups in FMD (P = 0.46), NTGMD (P = 0.42), RHVTI (P = 0.17), and FMD/RHVTI (P = 0.22) in unadjusted comparisons. Adjusted ANOVA models which included brachial artery diameter, demographics, and conventional CVD risk factors did not appreciably change these findings. In pairwise comparisons, the HIV+ART- group had significantly higher soluble tumor necrosis factor receptor II, soluble CD163, β-2 microglobulin, interferon-γ- induced protein-10, tissue inhibitor of metalloproteinase-1, and vascular cell adhesion molecule-1 compared to the other two groups (all p<0.05). Correlates of endothelial function differed between study groups.

Conclusion

Although untreated HIV infection was associated with elevated levels of several biomarkers of inflammation and endothelial activation, we were unable to demonstrate differences in measures of conduit artery and microvascular endothelial function in this study population.

Intima-Media Thickness in the Carotid and Femoral Arteries for Detection of Arteriosclerosis in Human Immunodeficiency Virus-Positive Individuals

BACKGROUND

The prevalence of atherosclerosis is higher in HIV-positive people, who also experience it earlier than the general population.

OBJECTIVES

To assess and compare the prevalence of atherosclerosis evaluated by the intima-media thickness of carotid and femoral arteries, and by the ankle-brachial pressure index (ABPI) in HIV patients treated or not treated with protease inhibitors (PIs) and controls.

METHODS

Eighty HIV+ subjects (40 using PIs and 40 not using PIs) and 65 controls were included in the study. Atherosclerosis was diagnosed by (carotid and femoral) ITM measurement and ABPI. Classical risk factors for atherosclerosis and HIV were compared between the groups by statistical tests. A p ≤ 0.05 was considered significant.

RESULTS

An IMT > P75 or the presence of plaque was higher in the HIV+ than in the control group (37.5% vs 19%, p = 0.04). Comparative analysis showed a significant difference (p=0.014) in carotid IMT between HIV+ with PIs (0.71 ± 0.28 mm), without PIs 0.63 ± 0.11 mm and, and controls (0.59 ± 0.11 mm). There was no significant difference in femoral IMT between the groups or in ABPI between HIV+ subjects and controls. However, a significant difference (p=0.015) was found between HIV+ patients not treated with PIs (1.17 [1.08 - 1.23]), and controls 1.08 [1.07 - 1.17]).

CONCLUSION

In HIV patients, atherosclerosis is more prevalent and seems to occur earlier with particular characteristics compared with HIV-negative subjects.

Coronary artery endothelial dysfunction is present in HIV-positive individuals without significant coronary artery disease

OBJECTIVE

HIV-positive (HIV+) individuals experience an increased burden of coronary artery disease (CAD) not adequately accounted for by traditional CAD risk factors. Coronary endothelial function (CEF), a barometer of vascular health, is depressed early in atherosclerosis and predict future events but has not been studied in HIV+ individuals. We tested whether CEF is impaired in HIV+ patients without CAD as compared with an HIV-negative (HIV-) population matched for cardiac risk factors.

DESIGN/METHODS

In this observational study, CEF was measured noninvasively by quantifying isometric handgrip exercise-induced changes in coronary vasoreactivity with MRI in 18 participants with HIV but no CAD (HIV+CAD-, based on prior imaging), 36 age-matched and cardiac risk factor-matched healthy participants with neither HIV nor CAD (HIV-CAD-), 41 patients with no HIV but with known CAD (HIV-CAD+), and 17 patients with both HIV and CAD (HIV+CAD+).

RESULTS

CEF was significantly depressed in HIV+CAD- patients as compared with that of risk-factor-matched HIV-CAD- patients (P < 0.0001) and was depressed to the level of that in HIV- participants with established CAD. Mean IL-6 levels were higher in HIV+ participants (P < 0.0001) and inversely related to CEF in the HIV+ patients (P = 0.007).

CONCLUSION

Marked coronary endothelial dysfunction is present in HIV+ patients without significant CAD and is as severe as that in clinical CAD patients. Furthermore, endothelial dysfunction appears inversely related to the degree of inflammation in HIV+ patients as measured by IL-6. CEF testing in HIV+ patients may be useful for assessing cardiovascular risk and testing new CAD treatment strategies, including those targeting inflammation.

Is the atherosclerotic process accentuated under conditions of HIV infection, antiretroviral therapy, and protease inhibitor exposure? Meta-analysis of the markers of arterial structure and function

OBJECTIVE

To evaluate the apparent association of human immunodeficiency virus (HIV) infection, antiretroviral therapy (ART), and protease inhibitor (PI) exposure with the functional and structural markers of vasculature.

METHODS

A meta-analysis of the relationship between HIV infection, ART, and PI exposure and the functional and structural markers of vasculature. A systematic literature search was performed electronically using specific eligibility criteria. Weighted mean difference (WMD) and corresponding 95% confidence interval (CI) were calculated and combined appropriately.

RESULTS

Fifty-seven articles were included with nine different outcomes. Compared with HIV-negative patients, HIV-positive patients demonstrated significant elevated intima-media thickness (IMT) (WMD (95% CI) = 0.042 (0.028-0.057)), increased pulse wave velocity (PWV) (0.538 (0.283-0.792)), and reduced flow-mediated vasodilation (FMD) (-2.049 (-2.806 to -1.293)). Elevated IMT was observed in HIV patients receiving ART when compared with those naïve to ART in the 20- to 40-year-old age group (0.078 (0.033-0.123)), the >40-year-old age group (0.038 (0.018-0.057)), and the group comprising >50% males (0.070 (0.041-0.099)). In addition, ART resulted in an increased PWV in HIV patients receiving ART in the group with >50% male proportion (0.628 (0.405-0.851)). HIV patients exposed to PI showed a significant trend toward elevated IMT (0.033 (0.007-0.058)) and increased PWV (0.264 (0.118-0.410)) compared with those without PI exposure.

CONCLUSIONS

The atherosclerotic process was accentuated by elevated IMT, increased PWV, and reduced FMD under condition of HIV infection. Comparison of ART-receiving with ART-naïve patients showed a significant trend toward elevated IMT and increased PWV, especially under treatment with PI-containing drugs.

Long-term use of first-line highly active antiretroviral therapy is not associated with carotid artery stiffness in human immunodeficiency virus-positive patients

Objective

To evaluate whether or not highly active antiretroviral therapy is associated with carotid artery stiffness in human immunodeficiency virus-positive patients in Henan Province, China.

Method

Fifty human immunodeficiency virus-positive patients with at least a 5-year history of highly active antiretroviral therapy use and 50 human immunodeficiency virus-positive patients without a history of highly active antiretroviral therapy use were enrolled in this study. Carotid artery intima-media thickness and stiffness were determined by quantitative inter-media thickness and quantitative artery stiffness, respectively.

Results

No statistically significant difference in carotid artery intima-media thickness and stiffness was observed between groups. A significant association between human immunodeficiency virus infection time and carotid artery stiffness was observed, but no significant association between human immunodeficiency virus infection time and intima-media thickness was found. No significant association between intima-media thickness, stiffness, and CD4⁺ and CD8⁺ T-cell counts were observed.

Conclusion

The first-line highly active antiretroviral therapy currently used in China is not associated with carotid artery stiffness in human immunodeficiency virus-positive patients with good highly active antiretroviral therapy compliance. Human immunodeficiency virus may play a role in the development of atherosclerosis.

Imbalance between endothelial progenitors cells and microparticles in HIV-infected patients naive for antiretroviral therapy

BACKGROUND

Cardiovascular events have been reported among HIV-infected patients following antiretroviral therapy. However, the role of HIV itself in determining vascular damage is less described. Chronic inflammatory state might impair some regulatory endothelium properties leading to its activation, apoptosis or erosion.

OBJECTIVES

To evaluate the balance between endothelial progenitor cells and microparticles in HIV-infected antiretroviral drug-naive patients.

DESIGN

A case-control study comparing HIV-infected patients (n = 35) with sex-matched and age-matched healthy controls (n = 33).

METHODS

Endothelial progenitor cells populations expressing CD34, CD133 and KDR were quantified by flow cytometry. Endothelial-derived microparticles, expressing CD51, and platelet-derived microparticles, expressing CD31/CD42, were also measured. Endothelial function was estimated by flow-mediated dilation.

RESULTS

Lower percentages of endothelial progenitor cells (CD34/KDR) were observed in HIV-infected individuals compared with controls (0.02 vs. 0.09%, P = 0.045). In addition, endothelial microparticles concentration was higher in HIV-infected individuals (1963 vs. 436 microparticles/μl platelet-poor plasma, P = 0.003), with similar number of platelet-derived microparticles among groups. Furthermore, flow-mediated dilation was lower among HIV-infected individuals compared with controls [mean (SEM): 10 (1) and 16% (2), respectively; P = 0.03].

CONCLUSION

Our findings suggest an imbalance between endothelial progenitor cells mobilization and endothelial apoptosis. The alteration in the turnover of endothelial cells may contribute to cardiovascular events in HIV-infected patients.

Cardiovascular implications of HIV-induced dyslipidemia

Cardiovascular disease (CVD) is currently the second most frequent cause of death (after cancer) among HIV-positive subjects. The clinical use of highly active antiretroviral therapy (HAART) has dramatically reduced mortality and morbidity in HIV-positive population, leading to prolonged and improved quality of life. However, as mortality and morbidity from AIDS-related conditions improve, CVD assumes increasing magnitude. It is estimated that by 2015 more than 50% of HIV-positive patients will be older than 50 years. Since age is a major unmodifiable cardiovascular risk factor, the risk for CVD in this population will significantly and progressively increase in the near future. A large part of the risk for cardiovascular events appears to be a result of lipid abnormalities characterizing HIV-positive persons. This review focuses on HIV-associated lipid abnormalities and CVD. Lipid abnormalities may be related to either viral infection, HAART or both. Dyslipidemia characterizing HIV-infected patients has become a therapeutic target to reduce cardiovascular risk of HIV-treated patients. HAART-treated patients show an atherogenic lipid profile comprised of low HDL-cholesterol levels, hypertrigliceridemia and increased levels of small-LDL particles. Current guidelines for the treatment of dyslipidemia and reducing cardiovascular risk in HIV-positive patients suggest that when lifestyle modifications (i.e., diet and exercise) and switching antiretroviral therapy are not enough, statins should be the first-line therapy for dyslipidemia. HDL raising interventions (niacin and fibrates) should be considered to raise HDL levels and lower triglyceride in HIV-infected patients. Implications of lipid-related interventions in HIV-treated patients to avoid drug interactions and their adverse effects are also discussed.

Protease inhibitor therapy in resource-limited settings

PURPOSE OF REVIEW

The use of protease inhibitors in resource-limited settings will increase in coming years as HIV treatment cohorts mature. We review data available to guide the expanded use of protease inhibitors in these settings.

RECENT FINDINGS

The safety and effectiveness of protease inhibitors may be affected by the context of their use, yet limited data exist regarding the use of these agents in resource-limited settings in either first or subsequent regimens. Critically, data are needed regarding optimal regimens at time of first-line nonnucleoside reverse transcriptase inhibitor-based regimen failure. A number of alternative strategies are being investigated, including dual-boosting, monotherapy and dose reduction. Despite recent progress cost, storage requirements, drug interactions and formulation continue to hinder the use of protease inhibitors, particularly for children.

SUMMARY

Protease inhibitors are the core component of second-line therapy in resource-limited settings and are used in specific situations in first-line therapy. Use of second-line regimens has been more diverse than first line, but WHO has recently prioritized regimens containing lopinavir/ritonavir or ritonavir-boosted atazanavir. As use of protease inhibitors in resource-limited settings increases evidence needs to be accrued to guide further expanded use.