Interleukin 6 is associated with subclinical atherosclerosis: a link with soluble intercellular adhesion molecule 1

Personalized Intervention Based on Early Detection of Atherosclerosis: JACC State-of-the-Art Review

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality worldwide and challenges the capacity of health care systems globally. Atherosclerosis is the underlying pathophysiological entity in two-thirds of patients with CVD. When considering that atherosclerosis develops over decades, there is potentially great opportunity for prevention of associated events such as myocardial infarction and stroke. Subclinical atherosclerosis has been identified in its early stages in young individuals; however, there is no consensus on how to prevent progression to symptomatic disease. Given the growing burden of CVD, a paradigm shift is required-moving from late management of atherosclerotic CVD to earlier detection during the subclinical phase with the goal of potential cure or prevention of events. Studies must focus on how precision medicine using imaging and circulating biomarkers may identify atherosclerosis earlier and determine whether such a paradigm shift would lead to overall cost savings for global health.

Associations of childhood adiposity with adult intima-media thickness and inflammation: a 20-year longitudinal population-based cohort

BACKGROUND

The associations between childhood adiposity and adult increased carotid intima-media thickness (cIMT) have been well established, which might be corroborated by the association between adiposity in children and inflammation in adults. However, longitudinal data regarding biological pathways associated with childhood adiposity are lacking.

METHODS

The current study included participants from the STANISLAS cohort who had adiposity measurements at age 5-18 years [ N  = 519, mean (SD) age, 13.0 (2.9) years; 46.4% male], and who were measured with cIMT, vascular-related and metabolic-related proteins at a median follow-up of 19 ± 2 years. BMI, waist-to-height ratio and waist circumference were converted to age-specific and sex-specific z -scores.

RESULTS

A minority of children were overweight/obese (16.2% overweight-BMI z -score >1; 1.3% obesity- z -score >2). Higher BMI, waist-height ratio and waist circumference in children were significantly associated with greater adult cIMT in univariable analysis, although not after adjusting for C-reactive protein. These associations were more pronounced in those with consistently high adiposity status from childhood to middle adulthood. Participants with higher adiposity during childhood (BMI or waist-height ratio) had higher levels of insulin-like growth factor-binding protein-1, protein-2, matrix metalloproteinase-3, osteopontin, hemoglobin and C-reactive protein in adulthood. Network analysis showed that IL-6, insulin-like growth factor-1 and fibronectin were the key proteins associated with childhood adiposity.

CONCLUSION

In a population-based cohort followed for 20 years, higher BMI or waist-to-height ratio in childhood was significantly associated with greater cIMT and enhanced levels of proteins reflective of inflammation, supporting the importance of inflammation as progressive atherosclerosis in childhood adiposity.

Serum sphingolipid profiling as a novel biomarker for metabolic syndrome characterization

Background

Sphingolipids are components of cell membrane structure, but also circulate in serum and are essential mediators of many cellular functions. While ceramides have been proposed previously as a useful biomarker for cardiometabolic disease, the involvement of other sphingolipids is still controversial. The aim of this study was to investigate the cross-sectional association between blood sphingolipidomic profiles and metabolic syndrome (MetS) as well as other atherosclerotic risk factors in a large population-based study in the U.S.

Methods

Clinical data and serum sphingolipidomic profiling from 2,063 subjects who participated in the biomarker project of the Midlife in the United States (MIDUS) study were used.

Results

Consistent with previous reports, we found a positive association between most ceramide levels and obesity, atherogenic dyslipidemia, impaired glucose metabolism, and MetS prevalence. In contrast, most simple β-glycosphingolipids (i.e., hexosylceramides and lactosylceramides) were inversely associated with dysmetabolic biomarkers. However, this latter sphingolipid class showed a positive link with inflammatory and vascular damage-associated biomarkers in subjects with MetS. Through metabolic network analysis, we found that the relationship between ceramides and simple β-glycosphingolipids differed significantly not only according to MetS status, but also with respect to the participants' C-reactive protein levels.

Conclusion

Our findings suggest that a comprehensive sphingolipid profile is more informative about MetS than ceramides alone, and it may reveal new insights into the pathophysiology and further diabetic vs. cardiovascular risk in patients with MetS.

The monomeric C-reactive protein level is associated with the increase in carotid plaque number in patients with subclinical carotid atherosclerosis

The high-sensitivity C-reactive protein (hsCRP) assay measures the level of the pentameric form of CRP in blood. Currently, there are no available assays measuring the level of the monomeric form of CRP (mCRP), produced at sites of local inflammation. We developed an assay measuring the mCRP level in blood plasma with functional beads for flow cytometry. The assay was used to measure the mCRP level in 80 middle-aged individuals with initially moderate cardiovascular SCORE risk. By the time of the mCRP measurement, the patients have been followed up for subclinical carotid atherosclerosis progression for 7 years. Ultrasound markers of subclinical atherosclerosis, which included plaque number (PN) and total plaque height (PH), were measured at baseline and at the 7th-year follow-up survey. Inflammatory biomarkers, including mCRP, hsCRP, inteleukin-6 (IL-6) and von Willebrand factor (VWF) level, were measured at the 7th-year follow-up survey. The median level of mCRP was 5.2 (3.3; 7.1) μg/L, hsCRP 1.05 (0.7; 2.1) mg/L, IL-6 0.0 (0.0; 2.8) pg/mL, VWF 106 (77; 151) IU/dL. In the patients with the mCRP level below median vs. the patients with the median mCRP level or higher, change from baseline in PN was 0.0 (0.0; 1.0) vs. 1.0 (1.0; 2.0) and PH 0.22 (−0.24; 1.91) mm vs. 1.97 (1.14; 3.14) mm, respectively (p < 0.05). The adjusted odds ratio for the formation of new carotid atherosclerotic plaques was 4.7 (95% CI 1.7; 13.2) for the patients with the median mCRP level or higher. The higher mCRP level is associated with the more pronounced increase in PN and PH in patients with normal level of traditional inflammatory biomarkers and initially moderate cardiovascular SCORE risk.

Regional and demographic variations of Carotid artery Intima and Media Thickness (CIMT): A Systematic review and meta-analysis

Background and objective

Carotid artery intima media thickness (CIMT) is a strong predictor of Coronary Heart Disease (CHD) and independent phenotype of early atherosclerosis. The global variation of CIMT and its demographic association is yet unclear. We evaluated regional variations of CIMT based on WHO regions and assessed the differences by age and sex.

Methods

A systematic search was conducted on studies published between 1980 January up to December 2020. PubMed, Oxford Medicine Online, EBSCO, Taylor & Francis, Oxford University Press and Embase data bases were used for searching. Supplementary searches were conducted on the Web of Science and Google Scholar. Grey literature was searched in “Open Grey” website. The two major criteria used were “adults” and “carotid intima media”. The search strategy for PubMed was created first and then adapted for the Oxford Medicine Online, EBSCO, Taylor & Francis, Oxford University Press and Embase databases. Covidence software (Veritas Health Innovation, Melbourne, Australia; http://www.covidence.org) was used to manage the study selection process. Meta-analyses were done using the random-effects model. An I2 ≥ 50% or p< 0:05 were considered to indicate significant heterogeneity.

Results

Of 2847 potential articles, 46 eligible articles were included in the review contributing data for 49 381 individuals (mean age: 55.6 years, male: 55.8%). The pooled mean CIMT for the non-CHD group was 0.65mm (95%CI: 0.62–0.69). There was a significant difference in the mean CIMT between regions (p = 0.04). Countries in the African (0.72mm), American (0.71mm) and European (0.71mm) regions had a higher pooled mean CIMT compared to those in the South East Asian (0.62mm), West Pacific (0.60mm) and Eastern Mediterranean (0.60mm) regions. Males had a higher pooled mean CIMT of 0.06mm than females in the non CHD group (p = 0.001); there were also regional differences. The CHD group had a significantly higher mean CIMT than the non-CHD group (difference = 0.23mm, p = 0.001) with regional variations. Carotid artery segment-specific-CIMT variations are present in this population. Older persons and those having CHD group had significantly thicker CIMTs.

Conclusions

CIMT varies according to region, age, sex and whether a person having CHD. There are significant regional differences of mean CIMT between CHD and non-CHD groups. Segment specific CIMT variations exist among regions. There is an association between CHD and CIMT values.

Sphingolipid Profiling: A Promising Tool for Stratifying the Metabolic Syndrome-Associated Risk

Metabolic syndrome (MetS) is a multicomponent risk condition that reflects the clustering of individual cardiometabolic risk factors related to abdominal obesity and insulin resistance. MetS increases the risk for cardiovascular diseases (CVD) and type 2 diabetes mellitus (T2DM). However, there still is not total clinical consensus about the definition of MetS, and its pathophysiology seems to be heterogeneous. Moreover, it remains unclear whether MetS is a single syndrome or a set of diverse clinical conditions conferring different metabolic and cardiovascular risks. Indeed, traditional biomarkers alone do not explain well such heterogeneity or the risk of associated diseases. There is thus a need to identify additional biomarkers that may contribute to a better understanding of MetS, along with more accurate prognosis of its various chronic disease risks. To fulfill this need, omics technologies may offer new insights into associations between sphingolipids and cardiometabolic diseases. Particularly, ceramides –the most widely studied sphingolipid class– have been shown to play a causative role in both T2DM and CVD. However, the involvement of simple glycosphingolipids remains controversial. This review focuses on the current understanding of MetS heterogeneity and discuss recent findings to address how sphingolipid profiling can be applied to better characterize MetS-associated risks.

Significantly higher atherosclerosis risks in patients with obstructive sleep apnea and non-alcoholic fatty liver disease

INTRODUCTION

There is limited data on the relationship between Obstructive Sleep Apnea (OSA) and Non-Alcoholic Fatty Liver Disease (NAFLD), each associated with increased cardiovascular risk. This study aimed to determine the relationships between severity of OSA, degree of steatosis in NAFLD and cardiovascular risk via CIMT and atherosclerosis markers ie intracellular adhesion molecule-1 (ICAM-1) an Lipoprotein-a (Lp(a)) in a group of patients with OSA.

MATERIALS AND METHODS

This was a cross-sectional, single center study. A total of 110 subjects between 18 to 65 years of age and diagnosed with OSA following sleep study examinations were recruited. Exclusion criteria included seropositive Hepatitis B or Hepatitis C, and significant alcohol intake.

RESULT

The prevalence of NAFLD was 81.8%. The mean CIMT (0.08±0.03 vs 0.06±0.01 cm, p = 0.001), ICAM-1 (334.53±72.86 vs 265.46±102.92 ng/mL, p = 0.001) and Lp(a) (85.41±52.56 vs 23.55±23.66 nmol/L, p<0.001) were significantly higher in the NAFLD group compared to the non-NAFLD group. Comparisons between the different groups showed significantly increasing levels of CIMT, ICAM-1 and Lp(a), lowest within the non-NAFLD, followed by the NAFLD 1 and NAFLD 2+3 groups. There was a significant positive correlation between degree of steatosis and the severity of OSA (r = 0.453, p<0.001). Logistic regression analysis revealed that patients with apnea/hypopnea index (AHI) of >30 were 52.77 (CI 6.34, 439.14) times more likely to have NAFLD compared to those with mild AHI (p<0.001).

CONCLUSION

The prevalence of NAFLD is alarmingly high in this group of OSA patients. The degree of steatosis in patients with NAFLD was significantly correlated with severity of OSA, CIMT measurements, ICAM-1 and Lp(a). Our findings underscore screening for NAFLD in patients with OSA to ensure prompt risk stratification and management.

Arterial structure and function in Africans with HIV for > 5 years: longitudinal relationship with endothelial activation and cardiovascular risk markers

OBJECTIVES

We aimed to determine whether people with human immunodeficiency virus (PWHIV) have increased measures of arterial injury [carotid intima-media thickness (cIMT)] and large artery stiffness [carotid-femoral pulse wave velocity (cfPWV)] when compared with their counterparts without HIV, and whether baseline markers of endothelial activation and cardiovascular risk are associated with cIMT and cfPWV after 5 years.

METHODS

We matched 126 PWHIV from North West Province, South Africa, to 126 without HIV according to age, sex and locality. Cardiovascular risk and endothelial function markers [soluble intracellular adhesion molecule (ICAM-1) and soluble vascular cell adhesion molecule (VCAM-1)] were measured at baseline and cIMT and cfPWV at follow-up.

RESULTS

This study included 21.4% men. The use of antiretroviral therapy (ART) increased from 44.1% at baseline to 81.4% at follow-up. At follow-up, cIMT (P = 0.90) and cfPWV (P = 0.35) were similar in the groups. Despite elevated ICAM-1 and VCAM-1 in the PWHIV (all P < 0.001) at baseline, these markers did not associate with cIMT and cfPWV after 5 years. In multivariable-adjusted regression analysis, cIMT associated positively with age (β = 0.31, P = 0.002) and triglyceride: high-density lipoprotein-cholesterol (β = 0.23, P = 0.016) in PWHIV. Mean arterial pressure (MAP) (β = 0.28, P = 0.010) associated positively with cfPWV in the PWHIV. In the people without HIV, sex (β = 0.31, P = 0.004) and glycated haemoglobin (HbA1c) (β = 0.24, P = 0.026) associated with cIMT while age (β = 0.17, P = 0.049), sex (β = 0.29, P = 0.003), MAP (β = 0.31, P = 0.001) and HbA1c (β = 0.21, P = 0.041) associated positively with cfPWV.

CONCLUSIONS

Measures of arterial structure and function were similar in Africans with HIV and their age, sex and locality matched controls. Traditional cardiovascular risk markers rather than elevated endothelial activation at baseline were independently associated with cIMT and cfPWV over 5 years.

Interleukin-6 level is a powerful predictor of long-term cardiovascular mortality in patients with acute coronary syndrome

BACKGROUND

The interleukin-6 (IL-6) pathway has a crucial role in the pathogenesis of atherosclerosis, the main cause of cardiovascular diseases. We aimed to characterize the predictive value of inflammatory biomarkers on long-term cardiovascular mortality in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI).

METHODS

This prospective observational study included 322 consecutive patients with ACS undergoing PCI. Blood-derived biomarkers IL-6 and high-sensitivity C-reactive protein (hsCRP) were assessed at the time point of ACS. Patients were followed-up for 6 years. Long-term cardiovascular mortality was our primary endpoint. Adjusted Cox-regression analysis was used for prediction of events.

RESULTS

Elevated IL-6 values (≥3.3 pg/mL) emerged as an independent and the most powerful predictor for cardiovascular mortality: the ROC analysis showed that IL-6 was more accurate for cardiovascular mortality prediction as compared to hsCRP (IL-6: AUC = 0.72; 95%CI: 0.62-0.81; p = 0.009 vs hsCRP: AUC = 0.56; 95%CI: 0.41-0.72; p = 0.445). The positive predictive value of IL-6 for mortality was 9%, the negative predictive value 99%, sensitivity 94% and specificity 48%. The primary endpoint of long-term cardiovascular death occurred more frequently in patients with high vs low IL-6 (9.0% vs 0.5%, p = 0.001). The multivariate Cox regression analysis revealed that patients with high IL-6 (≥3.3 pg/mL) values were at 8.6-fold higher hazard to die than those with low IL-6 (<3.3 pg/mL) levels (adj. hazard ratio [HR] = 8.60, 95%CI: 1.07-69.32; p = 0.043).

CONCLUSION

In the setting of ACS, high IL-6 values are associated with substantial long-term cardiovascular mortality. Further, IL-6 performs as a superior predictor for cardiovascular death as compared to hsCRP.

Modulation of the interleukin-6 signalling pathway and incidence rates of atherosclerotic events and all-cause mortality: analyses from the Canakinumab Anti-Inflammatory Thrombosis Outcomes Study (CANTOS)

Aims

Canakinumab, a monoclonal antibody targeting interleukin (IL)-1β, reduces rates of recurrent cardiovascular events without lowering lipids. It is uncertain, however, to what extent these beneficial cardiovascular outcomes are mediated through interleukin-6 (IL-6) signalling, an issue with substantial pathophysiologic consequences and therapeutic implications.

Methods and results

A total of 4833 stable atherosclerosis patients in the Canakinumab Anti-Inflammatory Thrombosis Outcomes Study (CANTOS) had IL-6 levels measured before randomization and after treatment with placebo or one of three doses of canakinumab (50 mg, 150 mg, or 300 mg) given subcutaneously once every 3 months. Participants were followed for up to 5 years (median follow-up 3.7 years). Compared with those allocated to placebo, CANTOS participants receiving canakinumab who achieved on-treatment IL-6 levels below the study median value of 1.65 ng/L experienced a 32% reduction in major adverse cardiovascular events [MACE, multivariable adjusted hazard ratio (HRadj) 0.68, 95% confidence interval (CI) 0.56-0.82; P < 0.0001], a 30% reduction in MACE plus the additional endpoint of hospitalization for unstable angina requiring urgent revascularization (MACE+, HRadj 0.70, 95% CI 0.59-0.84; P < 0.0001), a 52% reduction in cardiovascular mortality (HRadj 0.48, 95% CI 0.34-0.68; P < 0.0001), and a 48% reduction in all-cause mortality (HRadj 0.52, 95% CI 0.40-0.68; P < 0.0001) with prolonged treatment. In contrast, those with on-treatment IL-6 levels equal to or above 1.65 ng/L after taking the first dose of canakinumab had no significant benefit for any of these endpoints. These differential findings based on the magnitude of IL-6 response were seen in analyses alternatively based on tertiles of on-treatment IL-6 levels, and in analyses using a statistical inference approach to estimate the effect of treatment among individuals who would achieve a targeted IL-6 level.

Conclusion

CANTOS provides proof of concept evidence in humans that modulation of the IL-6 signalling pathway, at least with canakinumab, associates with reduced cardiovascular event rates, independent of lipid lowering.

Clinical trial registration

ClinicalTrials.gov NCT01327846.

Role of microRNA-15a-5p in the atherosclerotic inflammatory response and arterial injury improvement of diabetic by targeting FASN

The present study aims to investigate the mechanism of miR-15a-5p in the atherosclerotic (AS) inflammatory response and arterial injury improvement in diabetic rats by regulating fatty acid synthase (FASN). Initially, bioinformatics tools were applied to evaluate miRNAs and genes correlating with AS, and the target relation between miRNAs and FASN was measured using the Dual-Luciferase Reporter Assay. Subsequently the diabetic AS rat model was established and the surviving rats were divided into: negative control (NC), miR-15a-5p mimic, miR-15a-5p inhibitor, sh-FASN and miR-15a-5p + sh-FASN groups. Then a series of experiments were performed to examine the degree of AS in each group. The results revealed that compared with the NC group, the expressions of C-reactive protein (CRP), interleukin 6 (IL-6), intercellular cell adhesion molecule-1 (ICAM1) in rat arterial tissue, as well as the levels of low-density lipoprotein cholesterol (LDL-C), blood glucose (BG), triglycerides (TG), total cholesterol (TC) and Homocysteine (Hcy) in rat serum, were increased after inhibiting miR-15a-5p, while the level of high-density lipoprotein cholesterol (HDL-C) was decreased and the fat storage area was enlarged after this treatment (P<0.05). In the miR-15a-5p mimic and sh-FASN groups, serum HDL-C levels were increased and the fat storage areas in arteries were reduced. The levels of CRP, IL-6, ICAM1 in rat arterial tissue, along with the levels of LDL-C, BG, TG, TC and Hcy in rat serum, were decreased (P<0.05). Hematoxylin and Eosin (HE) staining and transmission electron microscopy (TEM) results showed AS lesions to be apparent in the arteries of rats in both the NC and miR-15a-5p inhibitor groups, but that in miR-15a-5p and sh-FASN group were improved, the miR-15a-5p mimic + sh-FASN group showed the most obvious improvement. Taken together, miR-15a-5p alleviates the inflammation response and arterial injury in diabetic AS rats by targeting FASN.

Inflammatory biomarkers and subclinical carotid atherosclerosis in HIV-infected and HIV-uninfected men in the Multicenter AIDS Cohort Study

BACKGROUND

HIV-infected persons have an increased risk of atherosclerosis relative to uninfected individuals. Inflammatory processes may contribute to this risk. We evaluated the associations of 10 biomarkers of systemic inflammation (CRP, IL-6, sTNF-αR1 and 2), monocyte activation (CCL2, sCD163, sCD14), coagulation (fibrinogen, D-dimer), and endothelial dysfunction (ICAM-1) with subclinical carotid atherosclerosis among participants in the Multicenter AIDS Cohort Study (MACS).

METHODS

Carotid plaque and intima media thickness (IMT) in the common carotid (CCA-IMT) and bifurcation region were assessed by B mode ultrasound among 452 HIV-infected and 276 HIV-uninfected men from 2010-2013. Associations between levels of each biomarker and presence of focal plaque and IMT were assessed by logistic and linear regression models, adjusting for demographics, risk behaviors, traditional cardiovascular disease (CVD) risk factors, and HIV disease characteristics.

RESULTS

Compared to HIV-uninfected men, HIV-infected men had significantly higher levels of 8 of the 10 biomarkers. Overall, men with sCD163, CCL2, IL-6, and CRP levels in the highest quintile had approximately 2 times the odds of carotid plaque relative to those with levels in the lowest quintile, independent of demographic and CVD risk factors. Fibrinogen levels were positively associated with CCA-IMT while ICAM-1, CCL2, and sTNF-αR1 levels were positively associated with bifurcation-IMT. Among HIV-uninfected men, higher levels of sTNF-αR2 were positively associated with CCA-IMT, fibrinogen with bifurcation-IMT and carotid plaque, and ICAM-1 with carotid plaque.

CONCLUSION

In addition to greater levels of systemic inflammation, heightened monocyte activation (sCD163, CCL2) may contribute to the burden of atherosclerosis among HIV-infected persons.

Regulation of platelet-activating factor-induced interleukin-8 expression by protein tyrosine phosphatase 1B

Background

Platelet-activating factor (PAF) is a potent lipid mediator whose involvement in the onset and progression of atherosclerosis is mediated by, among others, the modulation of cytokine expression patterns. The presence of multiple potential protein-tyrosine phosphatase (PTP) 1B substrates in PAF receptor signaling pathways brought us to investigate its involvement in PAF-induced cytokine expression in monocyte-derived dendritic cells (Mo-DCs) and to study the pathways involved in this modulation.

Methods

We used in-vitro-matured human dendritic cells and the HEK-293 cell line in our studies. PTP1B inhibition was though siRNAs and a selective inhibitor. Cytokine expression was studied with RT-PCR, luciferase assays and ELISA. Phosphorylation status of kinases and transcription factors was studied with western blotting.

Results

Here, we report that PTP1B was involved in the modulation of cytokine expression in PAF-stimulated Mo-DCs. A study of the down-regulation of PAF-induced IL-8 expression, by PTP1B, showed modulation of PAF-induced transactivation of the IL-8 promoter which was dependent on the presence of the C/EBPß -binding site. Results also suggested that PTP1B decreased PAF-induced IL-8 production by a glycogen synthase kinase (GSK)-3-dependent pathway via activation of the Src family kinases (SFK). These kinases activated an unidentified pathway at early stimulation times and the PI3K/Akt signaling pathway in a later phase. This change in GSK-3 activity decreased the C/EBPß phosphorylation levels of the threonine 235, a residue whose phosphorylation is known to increase C/EBPß transactivation potential, and consequently modified IL-8 expression.

Conclusion

The negative regulation of GSK-3 activity by PTP1B and the consequent decrease in phosphorylation of the C/EBPß transactivation domain could be an important negative feedback loop by which cells control their cytokine production after PAF stimulation.

Electronic supplementary material

The online version of this article (10.1186/s12964-019-0334-6) contains supplementary material, which is available to authorized users.

Femoral Artery Atherosclerosis Is Associated With Physical Function Across the Spectrum of the Ankle-Brachial Index: The San Diego Population Study

Background

The ankle‐brachial index (ABI) is inadequate to detect early‐stage atherosclerotic disease, when interventions to prevent functional decline may be the most effective. We determined associations of femoral artery atherosclerosis with physical functioning, across the spectrum of the ABI, and within the normal ABI range.

Methods and Results

In 2007–2011, 1103 multiethnic men and women participated in the San Diego Population Study, and completed all components of the summary performance score. Using Doppler ultrasound, superficial and common femoral intima media thickness and plaques were ascertained. Logistic regression was used to assess associations of femoral atherosclerosis with the summary performance score and its individual components. Models were adjusted for demographics, lifestyle factors, comorbidities, lipids, and kidney function. In adjusted models, among participants with a normal‐range ABI (1.00–1.30), the highest tertile of superficial intima media thickness was associated with lower odds of a perfect summary performance score of 12 (odds ratio=0.56 [0.36, 0.87], P=0.009), and lower odds of a 4‐m walk score of 4 (0.34 [0.16, 0.73], P=0.006) and chair rise score of 4 (0.56 [0.34, 0.94], P=0.03). Plaque presence (0.53 [0.29, 0.99], P=0.04) and greater total plaque burden (0.61 [0.43, 0.87], P=0.006) were associated with worse 4‐m walk performance in the normal‐range ABI group. Higher superficial intima media thickness was associated with lower summary performance score in all individuals (P=0.02).

Conclusions

Findings suggest that use of femoral artery atherosclerosis measures may be effective in individuals with a normal‐range ABI, especially, for example, those with diabetes mellitus or a family history of peripheral artery disease, when detection can lead to earlier intervention to prevent functional declines and improve quality of life.

Ex vivo foam cell formation is enhanced in monocytes from older individuals by both extrinsic and intrinsic mechanisms

Aging is the strongest predictor of cardiovascular diseases such as atherosclerosis, which are the leading causes of morbidity and mortality in elderly men. Monocytes play an important role in atherosclerosis by differentiating into foam cells (lipid-laden macrophages) and producing atherogenic proinflammatory cytokines. Monocytes from the elderly have an inflammatory phenotype that may promote atherosclerotic plaque development; here we examined whether they are more atherogenic than those from younger individuals. Using an in vitro model of monocyte transmigration and foam cell formation, monocytes from older men (median age [range]: 75 [58-85] years, n=20) formed foam cells more readily than those of younger men (32 [23-46] years, n=20) (P<0.003) following transmigration across a TNF-activated endothelial monolayer. Compared to young men, monocytes from the elderly had impaired cholesterol efflux and lower expression of regulators of cholesterol transport and metabolism. Foam cell formation was enhanced by soluble factors in serum from older men, but did not correlate with plasma lipid levels. Of the three subsets, intermediate monocytes formed the most foam cells. Therefore, both cellular changes to monocytes and soluble plasma factors in older men primes monocytes for foam cell formation following transendothelial migration, which may contribute to enhanced atherosclerosis in this population.

Circulating adhesion molecules and arterial stiffness

Aim

VCAM-1 and ICAM-1 are two important members of the immunoglobulin gene superfamily of adhesion molecules, and their potential role as biomarkers of diagnosis, severity and prognosis of cardiovascular disease has been investigated in a number of clinical studies. The aim of the present study was to determine the relationship between circulating ICAM-1 and VCAM-1 levels and aortic stiffness in patients referred for echocardiographic examination.

Methods

Aortic distensibility was determined by echocardiography using systolic and diastolic aortic diameters in 63 consecutive patients referred for echocardiography. Venous samples were collected in the morning after a 12-hour overnight fast, and serum concentrations of ICAM-1 and VCAM-1 were measured using commercial enzyme immunoassay kits.

Results

Data of a total of 63 participants (mean age 55.6 ± 10.5 years, 31 male) were included in the study. Circulating levels of adhesion molecules were VCAM-1: 12.604 ± 3.904 ng/ml and ICAM-1: 45.417 ± 31.429 ng/ml. We were unable to demonstrate any correlation between indices of aortic stiffness and VCAM-1 and ICAM-1 levels.

Conclusion

The role of soluble adhesion molecules in cardiovascular disease has not been fully established and clinical studies show inconsistent results. Our results indicate that levels of circulating adhesion molecules cannot be used as markers of aortic stiffness in patients.

Involvement of leucocyte/endothelial cell interactions in anorexia nervosa

BACKGROUND

Anorexia nervosa is a common psychiatric disorder in adolescence and is related to cardiovascular complications. Our aim was to study the effect of anorexia nervosa on metabolic parameters, leucocyte-endothelium interactions, adhesion molecules and proinflammatory cytokines.

MATERIALS AND METHODS

This multicentre, cross-sectional, case-control study employed a population of 24 anorexic female patients and 36 controls. We evaluated anthropometric and metabolic parameters, interactions between leucocytes polymorphonuclear neutrophils (PMN) and human umbilical vein endothelial cells (HUVEC), proinflammatory cytokines such as tumour necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) and soluble cellular adhesion molecules (CAMs) including E-selectin, vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1).

RESULTS

Anorexia nervosa was related to a decrease in weight, body mass index, waist circumference, systolic blood pressure, glucose, insulin and HOMA-IR, and an increase in HDL cholesterol. These effects disappeared after adjusting for BMI. Anorexia nervosa induced a decrease in PMN rolling velocity and an increase in PMN rolling flux and PMN adhesion. Increases in IL-6 and TNF-α and adhesion molecule VCAM-1 were also observed.

CONCLUSIONS

This study supports the hypothesis of an association between anorexia nervosa, inflammation and the induction of leucocyte-endothelium interactions. These findings may explain, in part at least, the increased risk of vascular disease among patients with anorexia nervosa.

Disruption of p21-activated kinase 1 gene diminishes atherosclerosis in apolipoprotein E-deficient mice

Pak1 plays an important role in various cellular processes, including cell motility, polarity, survival and proliferation. To date, its role in atherogenesis has not been explored. Here we report the effect of Pak1 on atherogenesis using atherosclerosis-prone apolipoprotein E-deficient (ApoE^−/−) mice as a model. Disruption of Pak1 in ApoE^−/− mice results in reduced plaque burden, significantly attenuates circulating IL-6 and MCP-1 levels, limits the expression of adhesion molecules and diminishes the macrophage content in the aortic root of ApoE^−/− mice. We also observed reduced oxidized LDL uptake and increased cholesterol efflux by macrophages and smooth muscle cells of ApoE^−/−:Pak1^−/− mice as compared with ApoE^−/− mice. In addition, we detect increased Pak1 phosphorylation in human atherosclerotic arteries, suggesting its role in human atherogenesis. Altogether, these results identify Pak1 as an important factor in the initiation and progression of atherogenesis.

Atherogenesis involves coordinated action of different cell types and factors. Here the authors show that the kinase Pak1 represents a key pro-atherogenic factor affecting the function of macrophages and vascular smooth muscle cells, including their production of proinflammatory cytokine IL-6 and chemokine MCP-1, and retention of cholesterol.

Association of inflammatory markers and poor outcome in diabetic patients presenting with ST segment elevation myocardial infarction

OBJECTIVE

Carbohydrate metabolism disorders (CMD) significantly impact the development and progression of all forms of ischemic heart disease, and inflammation is regarded as a general pathogenetic link between CMD and ischemic heart disease.

METHODS

A total of 601 patients with ST segment elevation myocardial infarction (MI) (STEMI), admitted within 24 hours from the onset of symptoms during 1 year, were included in this registry study. The blood levels of inflammation markers were measured at days 10-14 with further follow up at 1 year.

RESULTS

The analysis of acute-phase percutaneous coronary intervention impact on the 1-year outcomes showed that endovascular revascularization significantly improved the 1-year prognosis of STEMI patients both with and without CMD. The analysis of inflammation markers showed significantly higher levels of interleukin (IL)-6 and sCD40L in MI patients with diabetes mellitus, and impaired glucose tolerance. Additionally, the patients with impaired glucose tolerance had significantly higher IL-12 levels. In the diabetic MI patients, the odds ratio of a poor 1-year outcome was high for patients with a high Killip classification of acute heart failure upon admission.

CONCLUSION

Persistent inflammation in STEMI patients with CMD undergoing percutaneous coronary intervention might be responsible for vascular complications within 1 year after MI. Comorbid diabetes mellitus or impaired glucose tolerance can amplify the significance of the inflammatory response for the development of adverse 1-year outcomes.

Assessment of the body composition and parameters of the cardiovascular risk in juvenile idiopathic arthritis

The study was aimed to evaluate cardiovascular risk parameters, body mass index (BMI) centiles for sex and age, and body fat percentage using the electric bioimpedance method in children with juvenile idiopathic arthritis (JIA). 30 children with JIA participated in the study. A control group included 20 children. Patients were well matched for the age and sex. The body mass and body fat percentage were determined using the segmental body composition analyser; the BMI centiles were determined. All patients had the following parameters determined: lipid profile, hsCRP, homocysteine, and IL-6. The intima media thickness (IMT) was measured. Patients with JIA had significantly lower body weight, BMI, and the BMI centile compared to the control group. The IL-6 levels were significantly higher in patients with JIA compared to the control group. There were no differences between two groups with regard to the lipid profile, % content of the fat tissue, homocysteine levels, hsCRP, and IMT. Further studies are necessary to search for reasons for lower BMI and BMI centile in children with JIA and to attempt to answer the question of whether lower BMI increases the cardiovascular risk in these patients, similarly as in patients with rheumatoid arthritis (RA).

Lipoprotein-associated phospholipase A2 and cardiovascular disease risk in HIV infection

OBJECTIVES

HIV-infected patients on antiretroviral therapy (ART) have an increased cardiovascular disease (CVD) risk as a result of heightened inflammation and immune activation, despite at times having normal lipids and few traditional risk factors. Biomarkers are needed to identify such patients before a clinical event. Lipoprotein-associated phospholipase A2 (Lp-PLA2 ) predicts CVD events in the general population. This study investigated the relationship between Lp-PLA2 and markers of CVD risk, systemic inflammation, immune activation, and coagulation in HIV infection.

METHODS

One hundred subjects on stable ART with normal fasting low-density lipoprotein (LDL) cholesterol were enrolled in the study. Plasma Lp-PLA2 concentrations were measured by enzyme-linked immunosorbent assay (ELISA; > 200 ng/mL was considered high CVD risk). Subclinical atherosclerosis, endothelial function, inflammation, immune activation and fasting lipids were also evaluated.

RESULTS

The median age of the patients was 47 years and 77% were male. Median (range) Lp-PLA2 was 209 (71-402) ng/mL. Fifty-seven per cent of patients had Lp-PLA2 concentrations > 200 ng/mL. Lp-PLA2 was positively correlated with soluble markers of inflammation or immune activation (tumour necrosis factor receptor-II, intercellular and vascular cellular adhesion molecules, and CD14; all R = 0.3; P < 0.01), and negatively correlated with coagulation markers (D-dimer and fibrinogen; both R = -0.2; P < 0.04). Lp-PLA2 was not correlated with lipids, coronary artery calcium score, or flow-mediated vasodilation, but trended towards a significant correlation with carotid intima-media thickness (R = 0.2; P = 0.05).

CONCLUSIONS

In this population with stable ART and normal LDL cholesterol, Lp-PLA2 was in the high CVD risk category in the majority of subjects. Lp-PLA2 appears to be associated with inflammation/immune activation, but also with anti-thrombotic effects. Lp-PLA2 may represent a valuable early biomarker of CVD risk in HIV infection before subclinical atherosclerosis can be detected.

Effect of 24 weeks of statin therapy on systemic and vascular inflammation in HIV-infected subjects receiving antiretroviral therapy

BACKGROUND

Human immunodeficiency virus (HIV)-infected individuals are at increased risk of cardiovascular disease (CVD) due in part to inflammation. Statins decrease inflammation in the general population, but their effect during HIV infection is largely unknown.

METHODS

This is an ongoing randomized, double-blinded, placebo-controlled trial to evaluate the effect of statin therapy on inflammatory markers during HIV infection. Subjects received rosuvastatin 10 mg daily or placebo for 24 weeks. Subjects were receiving stable (>12 weeks) antiretroviral therapy and had a low-density lipoprotein (LDL) cholesterol level of ≤130 mg/dL and evidence of heightened immune activation or inflammation. This was a prespecified interim analysis.

RESULTS

A total of 147 subjects were enrolled (78% were male, 70% were black, and the median age was 47 years). By 24 weeks, LDL cholesterol levels had decreased in the statin group, compared with an increase in the placebo group (-28% vs +3.8%; P < .01). A 10% reduction in the lipoprotein-associated phospholipase A2 (Lp-PLA2) level was seen in the statin group, compared with a 2% reduction in the placebo group (P < .01). In multivariable regression, receipt of statin treatment and having a nadir CD4(+) T-cell count of ≤100 cell/µL were the only statistically significant predictors of a decrease in Lp-PLA2 level. Markers of systemic inflammation did not change significantly between groups.

CONCLUSIONS

Twenty-four weeks of rosuvastatin therapy significantly decreased the level of Lp-PLA2, a vascular-specific, inflammatory enzyme that predicts cardiovascular events in the general population. Statins may hold promise as a means of attenuating CVD risk in HIV-infected individuals by decreasing Lp-PLA2 levels.

Microbial translocation in the pathogenesis of HIV infection and AIDS

In pathogenic simian immunodeficiency virus (SIV) and human immunodeficiency virus (HIV) infections, the translocation of microbial products from the gastrointestinal (GI) tract to portal and systemic circulation has been proposed as a major driver of the chronic immune activation that is associated with disease progression. Consistently, microbial translocation is not present in nonpathogenic SIV infections of natural host species. In vivo studies demonstrated that HIV/SIV-associated microbial translocation results from a series of immunopathological events occurring at the GI mucosa: (i) early and severe mucosal CD4(+) depletion, (ii) mucosal immune hyperactivation/persistent inflammation; (iii) damage to the integrity of the intestinal epithelium with enterocyte apoptosis and tight junction disruption; and (iv) subverted the gut microbiome, with a predominance of opportunistic bacteria. Direct in situ evidence of microbial translocation has been provided for SIV-infected rhesus macaques showing translocated microbial products in the intestinal lamina propria and distant sites. While the mechanisms by which microbial translocation causes immune activation remain controversial, a key pathogenic event appears to be innate immunity activation via Toll-like receptors and other pathogen recognition receptors. Accumulating clinical observations suggest that microbial translocation might affect HIV disease progression, response to therapy, and non-AIDS comorbidities. Given its detrimental effect on overall immunity, several interventions to prevent/block microbial translocation are currently under investigation as novel therapeutic agents for HIV/AIDS.

Effects of pregnancy on endothelial function and cardiovascular disease risk in HIV-infected women

OBJECTIVE

This study assessed flow-mediated vasodilation (FMD) and brachial artery diameter (BAD) in HIV-infected pregnant women compared to healthy pregnant controls, and determined their relationships to variables of interest, including the HIV status.

METHODS

Subjects were enrolled prospectively for this longitudinal, observational study. Body mass index (BMI), blood pressure (BP), fasting lipoprotein profiles, homeostasis model assessment of insulin resistance (HOMA-IR), FMD, and BAD were assessed at 10-12, 20-22, and 32-35weeks gestation in HIV-infected women and healthy controls aged 18-45years with singleton pregnancies.

RESULTS

Fourteen HIV-infected women and 19 controls were enrolled. Groups were similar at baseline except there were more Caucasians in the control group (P<0.01). FMD and BAD did not change during pregnancy in either group, and there were no differences between groups. In multivariable regression analysis, FMD was associated with BAD (P=0.002), but not with age, BMI, BP, TC, TG, HOMA-IR, or HIV status. No variables were associated with BAD.

CONCLUSION

No differences were observed in FMD or BAD between HIV-infected and healthy pregnant women, and neither measure changed significantly during pregnancy. HIV status did not affect endothelial function or brachial artery diameter. Pregnancy does not appear to further increase the CVD risk associated with HIV infection.

T-cell phenotypes, apoptosis and inflammation in HIV+ patients on virologically effective cART with early atherosclerosis

Objective

We investigated the potential relationship between T-cell phenotype, inflammation, endotoxemia, and atherosclerosis evaluated by carotid intima-media thickness (IMT) in a cohort of HIV-positive patients undergoing long-term virologically suppressive combination antiretroviral therapy (cART).

Design

We studied 163 patients receiving virologically suppressive cART.

Methods

We measured IMT (carotid ultrasound); CD4+/CD8+ T-cell activation (CD38, CD45R0), differentiation (CD127), apoptosis (CD95), and senescence (CD28, CD57) (flow cytometry); plasma sCD14, IL-6, TNF- α, sVCAM-1, hs-CRP, anti-CMV IgG (ELISA); LPS (LAL). The results were compared by Mann-Whitney, Kruskal-Wallis or Chi-square tests, and factors associated with IMT were evaluated by multivariable logistic regression.

Results

Of 163 patients, 112 demonstrated normal IMT (nIMT), whereas 51 (31.3%) had pathological IMT (pIMT: ≥1 mm). Of the patients with pIMT, 22 demonstrated an increased IMT (iIMT), and 29 were shown to have plaques. These patient groups had comparable nadir and current CD4+, VLs and total length of time on cART. Despite similar proportions of CD38-expressing CD8+ cells (p = .95), pIMT patients exhibited higher activated memory CD8+CD38+CD45R0+ cells (p = .038) and apoptotic CD4+CD95+ (p = .01) and CD8+CD95+ cells (p = .003). In comparison to nIMT patients, iIMT patients tended to have lower numbers of early differentiated CD28+CD57− memory CD4+ (p = .048) and CD28–CD57−CD8+ cells (p = .006), both of which are associated with a higher proliferative potential. Despite no differences in plasma LPS levels, pIMT patients showed significantly higher circulating levels of sCD14 than did nIMT patients (p = .046). No differences in anti-CMV IgG was shown. Although circulating levels of sCD14 seemed to be associated with a risk of ATS in an unadjusted analysis, this effect was lost after adjusting for classical cardiovascular predictors.

Conclusions

Despite the provision of full viral suppression by cART, a hyperactivated, pro-apoptotic T-cell profile characterizes HIV-infected patients with early vascular damage, for whom the potential contribution of subclinical endotoxemia and anti-CMV immunity should be investigated further.

Tesaglitazar ameliorates non-alcoholic fatty liver disease and atherosclerosis development in diabetic low-density lipoprotein receptor-deficient mice

Previous research has demonstrated that the dual PPARα/γ agonist tesaglitazar reduces atherosclerosis in a mouse model of hyperlipidemia by reducing both lipid content and inflammation in the aorta. However, much of the underlying mechanism of tesaglitazar in non-alcoholic fatty liver disease (NAFLD) remains less clear. The aim of the present study was to determine whether tesaglitazar attenuates NAFLD and atherosclerosis development in diabetic low-density lipoprotein receptor-deficient (LDLr^−/−) mice. Female LDLr^−/− mice (3 weeks old) were induced by a high-fat diet (HFD) combined with low-dose streptozotocin (STZ) injection to develop an animal model of type 2 diabetes (T2DM). The mice were randomly divided into two groups: diabetic group (untreated diabetic mice, n=15) and tesaglitazar therapeutic group (n=15, 20 μg/kg/day oral treatment for 6 weeks). Fifteen LDLr^−/− mice were fed with an HFD as the control group. Tesaglitazar decreased serum glucose and lipid levels compared with the diabetic mice. Tesaglitazar significantly reduced atherosclerotic lesions, lipid accumulation in the liver, macrophage infiltration, and decreased total hepatic cholesterol and triglyceride content compared to the diabetic mice. In addition, tesaglitazar reduced inflammatory markers at both the serum and mRNA levels. Our data suggest that tesaglitazar may be effective in preventing NAFLD and atherosclerosis in a pre-existing diabetic condition by regulating glucose and lipid metabolism, and the inflammatory response.

[Influence of non-alcoholic fatty liver disease on cardiovascular disease]

Non-alcoholic fatty liver disease encompasses a spectrum ranging from simple steatosis to steatohepatitis without excess alcohol intake and is considered to be the hepatic manifestation of metabolic syndrome. Recent studies indicate that non-alcoholic fatty liver disease is closely related to cardiovascular disease, especially to thickening of the intima-media layer of the carotid artery, as the morphostructural manifestation of the presence of subclinical atheromatosis. Therefore, the correct management of non-alcoholic fatty liver disease would allow the natural history of both the liver disease and the atherosclerosis to be modified.

Zinc oxide nanoparticles-induced intercellular adhesion molecule 1 expression requires Rac1/Cdc42, mixed lineage kinase 3, and c-Jun N-terminal kinase activation in endothelial cells

The explosive development of nanotechnology has caused an increase in unintended biohazards in humans and in the ecosystem. Similar to particulate matter, nanoparticles (NPs) are strongly correlated with the increase in incidences of cardiovascular diseases, yet the mechanisms behind this correlation remain unclear. Within the testing concentrations of 0.1-10 μg/ml, which did not cause a marked drop in cell viability, zinc oxide NPs (ZnO-NPs) induced intercellular adhesion molecule-1 (ICAM-1) messenger RNA, and protein expression in both concentration- and time-dependent manner in treated human umbilical vein endothelial cells (HUVECs). ZnO-NPs treatment cause the activation of Ras-related C3 botulinum toxin substrate 1 (Rac1)/cell division control protein 42 homolog (Cdc42) and protein accumulation of mixed lineage kinase 3 (MLK3), followed by c-Jun N-terminal kinase (JNK) and transcription factor c-Jun activation. Induction of ICAM-1 and phosphorylation of JNK and c-Jun could be inhibited by either JNK inhibitor SP600125 or Rac guanosine triphosphatase inhibitor NSC23766 pretreatment. In addition, pretreatment with NSC23766 significantly reduced MLK3 accumulation, suggesting the involvement of Rac1/Cdc42-MLK3-JNK-c-Jun signaling in the regulation of ZnO-NPs-induced ICAM-1 expression, whereas these signaling factors were not activated in zinc oxide microparticles (ZnO-MPs)-treated HUVECs. The increase of ICAM-1 expression on ZnO-NPs-treated HUVECs enables leukocytes to adhere and has been identified as an indicator of vascular inflammation. Our data are essential for safety evaluation of the clinical usage of ZnO-NPs in daily supplements, cosmetics, and biomedicines.

Circulating soluble intercellular adhesion molecule 1 and subclinical atherosclerosis: the Coronary Artery Risk Development in Young Adults Study

BACKGROUND

Soluble intercellular adhesion molecule 1 (sICAM-1) is associated with endothelial dysfunction and clinical cardiovascular disease. We investigated the relationship of subclinical atherosclerosis with sICAM-1 concentration.

METHODS

sICAM-1 concentration was assayed at year 15 of the Coronary Artery Risk Development in Young Adults (CARDIA) Study (black and white men and women, average age 40 years). We assessed progression of coronary artery calcification (CAC) through year 20 (n = 2378), and both carotid artery stenosis (n = 2432) and intima-media thickness (IMT) at year 20 (n = 2240).

RESULTS

Median sICAM-1 was 145.9 μg/L. Among a subgroup with advanced atherosclerotic plaque (either CAC or stenosis), IMT was 0.010 (95% CI 0.003-0.017 mm) higher per SD of sICAM-1 (44 μg/L) in a model adjusted for age, race, sex, clinic, smoking, exercise, body size, education, blood pressure, antihypertensive medication, plasma lipids, and cholesterol-lowering medication. With the same adjustment, the odds ratio (OR) for the presence of year-20 carotid artery stenosis per SD of sICAM-1 was 1.12 (95% CI 1.01-1.25, P < 0.04), whereas for occurrence of CAC progression the OR was 1.16 (1.04-1.31, P < 0.01). The associations with CAC and carotid stenosis were strongest in the top 20th of the sICAM-1 distribution.

CONCLUSIONS

sICAM-1 concentration may be an early biomarker that indicates changes in the artery wall that accompany atherosclerosis, as well as the presence of advanced plaque in the coronary and carotid arteries. This finding holds in people with low total burden of atherosclerosis, decades before the development of clinical CVD.

Negative and competitive social interactions are related to heightened proinflammatory cytokine activity

Research has consistently documented that social relationships influence physical health, a link that may implicate systemic inflammation. We examined whether daily social interactions predict levels of proinflammatory cytokines IL-6 and the soluble receptor for tumor necrosis factor-α (sTNFαRII) and their reactivity to a social stressor. One-hundred twenty-two healthy young adults completed daily diaries for 8 d that assessed positive, negative, and competitive social interactions. Participants then engaged in laboratory stress challenges, and IL-6 and sTNFαRII were collected at baseline and at 25- and 80-min poststressor, from oral mucosal transudate. Negative social interactions predicted elevated sTNFαRII at baseline, and IL-6 and sTNFαRII 25-min poststressor, as well as total output of sTNFαRII. Competitive social interactions predicted elevated baseline levels of IL-6 and sTNFαRII and total output of both cytokines. These findings suggest that daily social interactions that are negative and competitive are associated prospectively with heightened proinflammatory cytokine activity.

Influenza vaccination promotes stable atherosclerotic plaques in apoE knockout mice

OBJECTIVE

Current evidence suggests a relationship between seasonal Influenza viral infection and cardiovascular disease (CVD). Experimental animals inoculated with Influenza A virus have shown to develop thrombotic complications similar to those seen in humans. Conversely, several epidemiological studies and clinical trials have suggested that Influenza vaccination may have a protective effect on CVD. However, the potential mechanisms behind this protective effect remain unstudied. We aimed to study the effect of Influenza vaccination on atherosclerotic plaque development in apoE(-/-) mice.

METHODS AND RESULTS

The effect of immunization with increasing doses of Influenza vaccine (0.38, 1.8, 9 and 45 μg/0.5 mL Vaxigrip®, Sanofi-Aventis) on atherogenesis was compared with that of animals immunized with Pneumo23® (pneumococcus vaccine, Sanofi-Aventis) and control group inoculated with phosphate buffered saline (PBS). Animals vaccinated with 45 μg/0.5 mL Vaxigrip®, (the same dose used to immunize humans adults against Influenza) developed smaller atherosclerotic lesions with lower lipid content but richer in smooth muscle cells and collagen when compared with control animals. Concomitantly, they showed lower levels of interferon gamma (IFNγ), interleukin (IL)-2 and tumor necrosis factor alpha (TNFα) but higher levels of IL-4. Furthermore, we found increased levels of anti-Influenza immunoglobulin (Ig) G1 or anti-Pneumo23® IgM specific antibodies in a time and dose dependent fashion in animals immunized with these vaccines.

CONCLUSIONS

These results indicate that vaccination against Influenza may protect against the development of CVD by promoting smaller and stable atherosclerotic plaques and by inducing atheroprotective immune responses.

Self-efficacy buffers the relationship between dementia caregiving stress and circulating concentrations of the proinflammatory cytokine interleukin-6

OBJECTIVE

the proinflammatory cytokine interleukin (IL)-6 has been linked with health morbidity, particularly risk for cardiovascular disease (CVD). The purpose of this study was to investigate the potential protective role of coping self-efficacy on the relationship between caregiving stress and circulating concentrations of IL-6.

METHODS

a total of 62 elderly caregivers of patients with Alzheimer's disease (mean age: 74 years) were assessed for plasma concentrations of IL-6, caregiving-related overload, and coping self-efficacy. Multiple regression was used to examine the main effects of stress and self-efficacy, as well as the interaction between stress and self-efficacy, in predicting plasma IL-6 after controlling for age, gender, resting blood pressure, and obesity.

RESULTS

there was a significant interaction between stress and self-efficacy in predicting IL-6. Post-hoc examination indicated that when self-efficacy was low, stress was significantly related to IL-6 (β = 0.43). However, when self-efficacy was high, stress was not significantly related to IL-6 (β = -0.10).

CONCLUSION

caregiving stress in combination with low coping self-efficacy is significantly related to IL-6, a known risk marker for health morbidity, particularly CVD. However, stress was not associated with IL-6 with high self-efficacy. Although limited and preliminary, these results point to a potential protective effect of self-efficacy on caregiver health that can be tested in longitudinal studies.

Interleukin-6 as an independent predictor of future cardiovascular events in high-risk Japanese patients: comparison with C-reactive protein

Inflammation is associated with the development of atherosclerotic vascular lesions and some inflammatory parameters are used as cardiovascular (CV) risk markers. The present study was designed to assess the predictive power of interleukin (IL)-6 for future CV events. In 121 Japanese patients with multiple CV risk factors and/or disease, serum concentrations of IL-6 and high sensitive C-reactive protein (hs-CRP) were measured. During follow-up periods (mean, 2.9 years) after the baseline assessment, 50 patients newly experienced CV events such as stroke/transient ischemic attack (n=10), heart failure hospitalization (n=6), acute coronary syndrome (n=7), and revascularization for coronary artery disease (n=15) and peripheral arterial disease (n=12). The serum level of IL-6, but not hs-CRP, was significantly higher in patients who had CV events than in event-free subjects (3.9±2.6 and 3.0±2.2 pg/mL, P=0.04). When the patients were divided into three groups by tertiles of basal levels of IL-6 (<1.85, 1.85-3.77, and ≥3.77 pg/mL), cumulative event-free rates by the Kaplan-Meier method were decreased according to the increase in basal IL-6 levels (65%, 50%, and 19% in the lowest, middle, and highest tertiles of IL-6, respectively; log-rank test, P=0.002). By univariate Cox regression analysis, previous CV disease, creatinine clearance, and serum IL-6 levels were significantly associated with CV events during follow-up. Among these possible predictors, the highest tertile of IL-6 was only an independent determinant for the morbidity in the multivariate analysis (hazard ratio 2.80 vs. lowest tertile, P=0.006). These findings indicate that IL-6 is a powerful independent predictor of future CV events in high-risk Japanese patients, suggesting its predictive value is superior to that of hs-CRP.

Expanded network of inflammatory markers of atherogenesis: where are we now?

Inflammatory biomarkers play a pivotal role in atherosclerotic lesions. The plasma levels of these markers are predictive of adverse outcomes such as myocardial infarction and cardiovascular death. The immune system is involved at all stages of atherogenesis via activation of monocytes/macrophages and T lymphocytes. Circulating proinflammatory cytokines and chemokines produced by these cells interact with specific receptors on various cells and activate specific signaling pathways, leading to inflammation-induced atherosclerotic lesions. Recent studies have focused on predictive value of inflammatory biomarkers such as C-reactive protein and interleukin-6. These biomarkers were shown to be associated with poor quality of life and predictive of adverse events in coronary atherosclerosis and left ventricular dysfunction. Vascular predictive value of other numerous inflammatory markers is being investigated. We herein analyze the role of several mediators of inflammation, affecting vascular functions and leading toward atherosclerotic lesions.

Expanded Network of Inflammatory Markers of Atherogenesis: Where Are We Now?

Inflammatory biomarkers play a pivotal role in atherosclerotic lesions. The plasma levels of these markers are predictive of adverse outcomes such as myocardial infarction and cardiovascular death. The immune system is involved at all stages of atherogenesisviaactivation of monocytes/macrophages and T lymphocytes.Circulating proinflammatory cytokines and chemokines produced by these cells interact with specific receptors on various cells and activate specific signaling pathways, leading to inflammation-induced atherosclerotic lesions. Recent studies have focused on predictive value of inflammatory biomarkers such as C-reactive protein and interleukin-6. These biomarkers were shown to be associated with poor quality of life and predictive of adverse events in coronary atherosclerosis and left ventricular dysfunction. Vascular predictive value of other numerous inflammatory markers is being investigated. We herein analyze the role of several mediators of inflammation, affecting vascular functions and leading toward atherosclerotic lesions.

Relationship between inflammatory markers, endothelial activation markers, and carotid intima-media thickness in HIV-infected patients receiving antiretroviral therapy

BACKGROUND

Human immunodeficiency virus (HIV)-infected patients are at increased risk of cardiovascular disease, which may be related to chronic inflammation and endothelial dysfunction despite virological control with antiretroviral therapy. The relationship between carotid intima-media thickness (IMT), a surrogate marker for cardiovascular disease, proinflammatory cytokines, and endothelial activation markers has not been fully explored in HIV-infected patients who are receiving antiretroviral therapy.

METHODS

We conducted a prospective, cross-sectional, observational study of treated HIV-infected patients and healthy control subjects to evaluate the relationship between carotid IMT, proinflammatory cytokines, endothelial activation biomarkers, and metabolic parameters in treated HIV-infected patients, compared with healthy control subjects.

RESULTS

We enrolled 73 HIV-infected patients and 21 control subjects. Common carotid artery and internal carotid artery IMT measurements, as well as tumor necrosis factor-alpha, high-sensitivity C-reactive protein, interleukin-6, myeloperoxidase, and soluble vascular cell adhesion molecule-1 levels were higher in the HIV-infected group. High-sensitivity C-reactive protein was the only biomarker that was positively correlated with carotid IMT in both groups. In the HIV-infected group, soluble vascular cell adhesion molecule-1 was positively correlated with all inflammatory cytokine levels. In multiple regression analysis, soluble vascular cell adhesion molecule-1, myeloperoxidase, and tumor necrosis factor-alpha levels were all associated with internal carotid artery IMT in the HIV-infected group, whereas age was associated with both common carotid artery and internal carotid artery IMT.

CONCLUSIONS

Enhanced endothelial activation, inflammation, and increased carotid IMT occur in HIV-infected patients despite antiretroviral therapy. Inflammatory markers are associated with endothelial activation, and both are associated with internal carotid artery IMT, supporting a potential role of inflammation in endothelial activation and cardiovascular disease in HIV infection.

Differential associations between soluble cellular adhesion molecules and atherosclerosis in the Dallas Heart Study: a distinct role for soluble endothelial cell-selective adhesion molecule

OBJECTIVE

Endothelial cell-selective adhesion molecule (ESAM) is a junctional-type cellular adhesion molecule (CAM) that is uniquely expressed in vascular endothelium and activated platelets and mediates neutrophil and monocyte diapedesis across the endothelium. Given its role in endothelial pathobiology, we hypothesized that soluble ESAM (sESAM) would be independently associated with atherosclerosis and vascular stiffness.

METHODS AND RESULTS

We measured sESAM, soluble intercellular adhesion molecule (sICAM)-1, and soluble vascular cell adhesion molecule (sVCAM)-1 in 3222 subjects participating in the Dallas Heart Study, a probability-based population sample. Coronary artery calcium (CAC) was measured by electron beam computed tomography, and abdominal aortic wall thickness (AWT), aortic plaque burden (APB), and aortic compliance (AC) by MRI. Increasing levels of sESAM were associated with all major cardiovascular risk factors as well as with inflammatory markers such as monocyte chemoattractant protein-1, but only weakly correlated with sICAM-1 and sVCAM-1. In multivariate analyses, sESAM was independently associated with prevalent CAC (OR 1.2 per SD increase, 95% CI 1.1 to 1.3; P=0.005), AWT (P=0.035), and AC (P=0.006), but not APB (P=0.15). In contrast, no independent associations were observed between sICAM-1 or sVCAM-1 and any of the atherosclerosis phenotypes.

CONCLUSIONS

In this first reported clinical study of sESAM in humans, sESAM levels were independently associated with CAC, AWT, and AC, whereas sICAM-1 and sVCAM-1 were not. These findings support a unique role of this cellular adhesion molecule in atherosclerosis and suggest the need for further exploration of sESAM as a predictive biomarker and potential mediator of atherosclerosis.

Serum IL-6 levels are associated with significant coronary stenosis in cardiovascularly asymptomatic inner-city black adults in the US

OBJECTIVES AND DESIGN

The objective of this study was to explore whether increased levels of inflammatory cytokines are associated with the risk of clinically silent coronary artery disease.

SUBJECTS

Three-hundred-fifty-six black adults aged 25-54 residing in inner city of Baltimore, Maryland, United States were included in this study.

METHODS

Sociodemographics were assessed as were lipid profiles, IL-6, tumor necrosis factor-alpha (TNF-alpha), soluble intercellular adhesion molecule-1 (sICAM-1), and high-sensitivity C-reactive protein (hs-CRP) levels. Computed tomography (CT) coronary angiography was performed.

RESULTS

Coronary calcification was identified in 22.5 % participants and 14 % had significant (>or=50 %) coronary stenosis. Multiple logistic regression analyses suggested that IL-6 levels were independently associated with the presence of coronary calcification and significant coronary stenosis, while TNF-alpha, sICAM-1 and hs-CRP levels were not.

CONCLUSIONS

This study underscores a critical role for IL-6 in atherosclerosis and suggests that IL-6 may be a marker for significant coronary stenosis in cardiovascularly asymptomatic individuals.

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

OBJECTIVES

To assess the association of inflammatory and endothelial activation biomarkers with the presence of lipoatrophy in HIV-infected subjects and to examine the role of HIV, antiretroviral therapy (ART), and metabolic parameters in endothelial activation and inflammation.

DESIGN

Prospective, cross-sectional study including 4 groups: HIV+ on ART with HIV-1 RNA<1000 copies/mL with and without clinical lipoatrophy, HIV+ ART naive, and healthy controls.

METHODS

We measured plasma levels of inflammatory cytokines (tumor necrosis factor-alpha, soluble tumor necrosis factor receptors I and II, interleukin-6, C-reactive protein, and myeloperoxidase) and endothelial activation markers (soluble intercellular and vascular cell adhesion molecules and von Willebrand factor).

RESULTS

We enrolled 182 subjects. Limb fat and lipoatrophy status were not correlated with endothelial markers. Endothelial markers were higher in HIV+ ART naive when compared with healthy controls and with HIV+ on ART but were similar between HIV+ on ART and healthy controls. Neither endothelial nor inflammatory markers were correlated with HIV duration, CD4 count, lipids, glucose, or specific ART. Strong correlations were found between some inflammatory cytokines and endothelial markers.

CONCLUSIONS

There is enhanced endothelial activation in ART naive, whereas HIV+ on ART has similar values to healthy controls. Lipoatrophy did not seem to affect endothelial activation. Results highlight a potential association between heightened inflammation and endothelial activation.

Th2-dependent cytokine release in patients treated with coronary angioplasty

AIM

The aim of this study is to investigate the T helper (Th)2-dependent release of interleukin(IL)-4 and IL-13 in patients with unstable angina treated with coronary angioplasty (PCI).

METHODS

This study involved 48 consecutive patients with unstable angina who underwent PCI. Blood samples were taken before and 48 h after PCI to evaluate serum IL-4 and IL-13 levels. Coronary atherosclerosis was assessed in terms of the severity of the treated lesions and the presence of multivessel disease, and compared with IL release.

RESULTS

Before and after PCI, serum IL-4 levels were, respectively, 53.1+/-110.7 and 35.1+/-16.9 pg/ml (P not significant), and serum IL-13 levels 6.7+/-3.7 and 6.0+/-2.9 pg/ml (P<0.05). A correlation was present between the severity of the treated coronary lesions and serum IL-13 levels (r 0.36; P<0.05). The patients with multivessel coronary artery disease had a higher periprocedure ratio of IL-4 than those with single-vessel coronary artery disease (1.46+/-0.76 vs. 0.89+/-0.34, P<0.001).

CONCLUSION

A significant decrease was observed in Th2-dependent IL concentrations after PCI; increased Th2-dependent IL levels before PCI seem to correlate with the severity of coronary atherosclerosis.

Epidermal growth factor levels are related to diastolic blood pressure and carotid artery stiffness

OBJECTIVES

The epidermal growth factor (EGF) is believed to be involved in vascular remodelling. EGF receptors are expressed in human atherosclerotic tissue.

DESIGN

In order to study the role of EGF in vascular remodelling and early progression of atherosclerosis, 17 men and 16 women aged 20 to 45 years were recruited. Common Carotid Artery Stiffness index (CCA SI) and blood pressure were evaluated. In addition, serum levels of EGF and blood lipids were measured.

RESULTS

The levels of serum EGF were significantly correlated to diastolic blood pressure (p<0.05) and CCA SI (p<0.05). Subjects with EGF concentrations in the upper median had significantly lower levels of HDL (High Density Lipoproteins) (p<0.05) and ApoA1 (Apolipoprotein) (p<0.05) than those with EGF concentrations in the lower median.

DISCUSSION

High serum level of EGF is associated with elevated diastolic blood pressure and increased vessel stiffness suggesting a possible functional role of EGF in the cardiovascular system in a healthy population.

Inflammatory angiogenesis in atherogenesis--a double-edged sword

The adventitia and the outer layers of media of an atherosclerosis-prone arterial wall are vascularized by vasa vasorum. Upon growth of an atherosclerotic lesion in the intima, neovascular sprouts originating from the adventitial vasa vasorum enter the lesion, the local proangiogenic micromilieu in the lesion being created by intramural hypoxia, by increased intramural oxidant stress, and by inflammatory cell infiltration (macrophages, T cells and mast cells). The angiogenic factors present in the lesions include various growth factors, chemokines, cytokines, proteinases, and several other factors possessing direct or indirect angiogenic activities, while the current list of antiangiogenic factors is smaller. An imbalance between endogenous inducers and inhibitors of angiogenesis, with a predominance of the former ones, is essential for the development of neovessels during the progression of the lesion. By providing oxygen and nutrients to the cells of atherosclerotic lesions, neovascularization initially tends to prevent cellular death and so contributes to plaque growth and stabilization. However, the inflammatory cells may induce rupture of the fragile neovessels, and so cause intraplaque hemorrhage and ensuing plaque destabilization. Pharmacological inhibition of angiogenesis in atherosclerotic plaques with ensuing inhibition of lesion progression has been achieved in animal models, but clinical studies aiming at regulation of angiogenesis in the atherosclerotic arterial wall can be designed only after we have reached a firm conclusion about the role of angiogenesis at various stages of lesion development--good or bad.