Association of interleukin-18 levels with global arterial function and early structural changes in men without cardiovascular disease

Gut Microbiota in Hypertension and Atherosclerosis: A Review

Gut microbiota and its metabolites such as short chain fatty acids (SCFA), lipopolysaccharides (LPS), and trimethylamine-N-oxide (TMAO) impact cardiovascular health. In this review, we discuss how gut microbiota and gut metabolites can affect hypertension and atherosclerosis. Hypertensive patients were shown to have lower alpha diversity, lower abundance of SCFA-producing microbiota, and higher abundance of gram-negative bacteria, which are a source of LPS. Animal studies point towards a direct role for SCFAs in blood pressure regulation and show that LPS has pro-inflammatory effects. Translocation of LPS into the systemic circulation is a consequence of increased gut permeability. Atherosclerosis, a multifactorial disease, is influenced by the gut microbiota through multiple pathways. Many studies have focused on the pro-atherogenic role of TMAO, however, it is not clear if this is a causal factor. In addition, gut microbiota play a key role in bile acid metabolism and some interventions targeting bile acid receptors tend to decrease atherosclerosis. Concluding, gut microbiota affect hypertension and atherosclerosis through many pathways, providing a wide range of potential therapeutic targets. Challenges ahead include translation of findings and mechanisms to humans and development of therapeutic interventions that target cardiovascular risk by modulation of gut microbes and metabolites.

Short- and Long-Term Effects of Bariatric Surgery on Vascular Phenotype

BACKGROUND

Retinal microvascular diameters and large artery stiffness are valid biomarkers of cardiovascular risk. This study assessed short- and long-term micro- and macrovascular improvements after bariatric surgery (BS).

METHODS

Sixteen patients (44 ± 12 years) underwent BS in this observational study. Two weeks before as well as 6 weeks and 4 years after surgery, retinal vessel analysis and assessment of brachial-ankle pulse wave velocity (baPWV), cardio-ankle vascular index (CAVI), and anthropometry were performed. Three patients were lost to follow-up.

RESULTS

Six weeks after BS, retinal arteriolar diameters (CRAE) were wider (180.1 μm vs. 188.1 μm; p = 0.001), and the arteriolar-to-venular diameter ratio (AVR) was higher (0.82 vs. 0.86; p < 0.001) compared to baseline levels. During the 4 years of follow-up, the retinal changes sustained but further improvements did not occur. Both indices of large artery stiffness, baPWV and CAVI, remained unchanged 6 weeks and 4 years after surgery.

CONCLUSIONS

Retinal microvascular phenotype improved 6 weeks after BS. The improvements in microvascular health were maintained during 4 years of follow-up but, despite significant further reductions in body mass index, did not improve further long-term. baPWV and CAVI were unaffected after surgery indicating that BS primarily affects microvascular phenotype rather than large artery stiffness. Retinal vessel imaging seems to be a feasible diagnostic tool to monitor microvascular health after BS. Normalization of BMI and blood pressure may be necessary to achieve long-term improvement of large artery phenotype after BS.

Serial assessment of endothelial vasomotor function using optimal medical therapy predicts clinical outcomes in patients after complete coronary revascularization

Objective

Previous studies have demonstrated the importance of intensive optimal medical therapy (OMT) in patients with coronary artery disease (CAD). To investigate our hypothesis that patients with and without OMT achievement differed with respect to the risk of future cardiac events, we investigated the endothelial function in patients with CAD who underwent percutaneous coronary intervention (PCI) and contemporary medical therapy.

Methods

We conducted a prospective longitudinal cohort study to evaluate the endothelial function in 96 consecutive patients at 12 h after admission and 3 months at <12 h after admission and at 3 months after discharge by measuring the brachial artery dilatation after 5 min of forearm ischemia flow-mediated dilation (FMD). OMT achievement was defined as systolic blood pressure of ≤130 mm Hg, low-density lipoprotein cholesterol of ≤100 mg/dl, and hemoglobin A1c level of ≤7.0%. The primary endpoint was the incidence of composite major adverse cardiac or cerebrovascular events (MACCE) at 36 months.

Results

Forty-nine (51%) patients achieved all three risk factor targets at 3 months. Although baseline FMD values did not differ between the OMT achievement and non-achievement groups, the 3-month FMD significantly improved in the OMT achievement group (6.6±3.5 vs. 5.2±2.9, p=0.03). Patients with improved FMD at 3 months had a lower rate of 36-month MACCE than those with persistently impaired FMD. A multiple Cox hazards analysis showed that OMT was a protective predictor of MACCE (hazard ratio, 0.19; 95% confidence interval, 0.04–0.88, p=0.03).

Conclusion

This study demonstrated a significant association between the serial measurement of endothelial function with OMT and the clinical outcome in patients after PCI.

Endothelial dysfunction evaluated by peripheral arterial tonometry is related with peak TnI values in patients with ST elevation myocardial infarction treated with primary angioplasty

PURPOSE

The role of endothelial-dependent function in patients with acute ST elevation myocardial infarction (STEMI) is not clear. Endothelial dysfunction may contribute to the pathophysiological processes occurring after STEMI and influence the extension of myocardial necrosis. Endothelial-dependent dysfunction evaluated by peripheral arterial tonometry (PAT) has already showed to be correlated with microvascular coronary endothelial dysfunction. Our purpose was to evaluate the impact of endothelial dysfunction on peak Troponin I (TnI) values, as a surrogate for the extension of myocardial infarction, in patients with STEMI treated with primary angioplasty (P-PCI).

METHODS

58 patients with STEMI treated with P-PCI (mean age 59.0 ± 14.0 years, 46 males) were included. Endothelial function was assessed by reactive hyperaemia index (RHI) determined by PAT. Patients were divided in two groups according to the previously reported RHI threshold for high risk (1.67). The extension of myocardial necrosis was evaluated by peak TnI levels.

RESULTS

RHI median value was 1.78 (IQR0.74);25 patients had endothelial dysfunction (RHI b 1.67). The two groups had no significant differences in age, gender, main risk factors and pain-to-balloon time. Patients with an RHI b 1.67 had significant larger infarcts: TnI 73.5 ng/mL (IQR 114.42 ng/mL) versus TnI 33.2 ng/mL (IQR 65.2 ng/mL); p = 0.028. On multivariate analysis, the presence of an RHI b 1.67 kept significant impact on TnI peak values (p=0.02).

CONCLUSIONS

The presence of endothelial-dependent dysfunction, assessed by PAT, is related with higher peak TnI values in STEMI patients treated with P-PCI. These results strength the possibility that endothelial-dependent dysfunction may be a marker of poor prognosis and eventually a therapeutic target in patients with STEMI.

Chronotropic Incompetence and Dynamic Postexercise Autonomic Dysfunction Are Associated with the Presence and Severity of Erectile Dysfunction

BACKGROUND

Exercise stress testing (EST) is crucial to determine cardiovascular (CV) risk in men with erectile dysfunction (ED). Low exercise workload, a slower rate of recovery following exercise, and an impaired capacity to increase heart rate (HR) during exercise testing (chronotropic incompetence) are independent predictors of adverse CV outcomes. Aim of this study was to investigate the association between ED and EST parameters.

METHODS

A total of 180 ED patients and 50 men without ED underwent maximal EST. Exercise parameters including exercise capacity (metabolic equivalents, METS), peak exercise time, HR at six METS, peak exercise, HR recovery (HRR) at 1 and 2 minutes and chronotropic index (CI) were evaluated in all individuals. Endothelial function was evaluated with flow-mediated dilatation (FMD) of the brachial artery.

RESULTS

ED patients had lower peak exercise time and thus lower calculated exercise capacity (P < 0.001) and reduced CI (P < 0.01) compared to men without ED. There was a significant association of ED severity with duration of exercise, peak workload, HRR 2 minutes after exercise, and CI (all P < 0.05). There also was a positive relation of HRR and CI with FMD (all P < 0.05).

CONCLUSIONS

This study shows interrelationships between exercise capacity, HRR, CI, and ED. Abnormal HRR and CI are associated with systemic endothelial dysfunction. These findings imply pathophysiological links and may have important implications for the estimation of cardiovascular risk in ED patients.

Interleukin-12 is associated with arterial stiffness in healthy individuals

BACKGROUND

Atherosclerotic cardiovascular disease (CVD) is a chronic inflammatory disease mediated by the proinflammatory cytokines interleukin-12 (IL-12) and interleukin-18 (IL-18). Evidence suggests that IL-12 is dominant in early atherosclerosis, while IL-18 is critical in advanced atherosclerosis. In this study, we explore the association between IL-12 and IL-18 and arterial stiffness in healthy individuals.

METHODS

We performed a cross-sectional study examining pulse wave velocity (PWV), augmentation index (AIx), IL-12, and IL-18 in healthy individuals (N = 53) without CVD risk factors.

RESULTS

In multivariate regression, age (P < 0.01), systolic blood pressure (P = 0.05), and IL-12 (P < 0.01) were positively associated with PWV, and high-density lipoprotein (P = 0.04) was negatively associated with PWV (model R (2) = 0.476, P < 0.01).

CONCLUSIONS

IL-12, but not IL-18, is associated with PWV in healthy individuals without clinical CVD, supporting a role for IL-12 in early atherosclerosis as suggested by animal studies.

Clinical correlates and prognostic value of flow mediated dilation in patients with non-ST segment elevation acute coronary syndromes

Endothelial dysfunction can predict cardiovascular outcomes in several populations of patients. The aim of this study was to assess the severity, time course, and clinical implications of endothelial dysfunction in patients with non-ST-segment elevation (NSTE) acute coronary syndromes (ACS). Sixty patients with NSTE ACS (mean age 62 ± 8 years, 44 men) and 40 controls with stable coronary artery disease (CAD) (mean age 63 ± 10 years, 27 men) were studied. In patients with NSTE ACS and in those with stable CAD, endothelial function was assessed <12 hours after admission and at 3-month follow-up by measuring right brachial artery dilation after 5 minutes of forearm ischemia (flow-mediated dilation [FMD]). Clinical outcomes were assessed after a median follow-up period of 32 months (range 14 to 36). The primary end point was a combination of cardiac death or readmission for new ACS or recurrence of angina pectoris. FMD on admission was significantly lower in patients with NSTE ACS compared to those with stable CAD (2.1 ± 1.2% vs 4.8 ± 1.9%, p <0.001). FMD improved significantly at 3-month follow-up in patients with NSTE ACS, becoming comparable to that in patients with stable CAD (5.7 ± 2.6% vs 5.5 ± 1.7%, p = 0.93). During follow-up, 14 cardiac events (23%) occurred in patients with NSTE ACS. On multivariate analysis, only diabetes (hazard ratio 18.1, 95% confidence interval 3.9 to 83.9, p <0.001) and FMD at 3 months (hazard ratio 0.78, 95% confidence interval 0.61 to 0.99, p = 0.04) were independent predictors of the primary end point in patients with NSTE ACS. In conclusion, endothelial function is markedly impaired in the acute phase of NSTE ACS but improves significantly at 3-month follow-up. In patients with NSTE ACS, FMD at 3 months after the acute event is a significant independent predictor of cardiac outcomes.

Early prediction of acute kidney injury in patients with acute myocardial injury

INTRODUCTION

Previous studies have revealed that acute myocardial infarction (AMI) with acute kidney injury (AKI), about 17%, is strongly related to long-term mortality and heart failure. The dynamic changes in renal function during AMI are strongly related to long-term mortality and heart failure.

OBJECTIVES

Our study used clinical parameters and AKI biomarkers including neutrophil gelatinase-associated lipocalin, interleukin (IL)-6, IL-18, and cystatin C to evaluate prognostic relevance of AKI in the setting of AMI.

METHODS

This prospective study was conducted from November 2009 to January 2011 and enrolled sequential 96 patients with catheter-proven AMI; it was approved by the institutional review board of Chang Gung Memorial Hospital, Taiwan (institutional review board no. 99-0140B) and conformed to the tenets of the Declaration of Helsinki. The definition of AKI is the elevation of serum creatinine of more than 0.3 mg/dL within 48 hours.

RESULTS

Our results show that the incidence of AKI after AMI is 17.7% (17 patients). The following could be statistically related to AKI after AMI: age (P = .012), cardiac functions (Killip stage and echocardiogram; P = .003 each), Thrombolysis in Myocardial Infarction (TIMI) flow grade (P < .001), stenting (P < .001), neutrophil gelatinase-associated lipocalin (P = .005), IL-6 (P = .01), IL-18 (P = .002), and cystatin C (P = .002) in serum. The TIMI flow grade and serum cystatin C were shown to be important predictors by using multivariate analysis. Both TIMI flow lower than grade 2 and serum cystatin C of more than 1364 mg/L could be used to predict AKI (both overall correctness, 0.78). Moreover, IL-6 in serum is also associated with the major cardiovascular events after AMI (P = .02), as demonstrated in our study.

CONCLUSION

In conclusion, the worse TIMI flow and high plasma cystatin C can be used to predict AKI after AMI. Moreover, IL-6 can also be used as a 30-day major cardiovascular event indicator after AMI. A larger prospective and longitudinal study should follow the relationship between AKI predictors after AMI.

Hypertensive nephropathy in children - do we diagnose early enough?

BACKGROUND/AIMS

The aim was to evaluate the level of neutrophil gelatinase-associated lipocalin (NGAL), interleukin 18 (IL-18) and retinol binding protein (RBP) in children with primary hypertension and no features of hypertensive nephropathy.

METHODS

The study group consisted of 19 children (15 males) aged 14.8 ± 2.18 years with primary hypertension. Estimated glomerular filtration rate (eGFR) and albumin/creatinine ratio (ACR) were within the normal range. Mean blood pressure (BP) was 141/79 mmHg (mean systolic BP percentile was 98, mean diastolic BP percentile was 80). Ambulatory BP measurement (ABPM), blood and urine biochemical measurements and features of end organ damage were assessed. The control group consisted of 20 healthy children.

RESULTS

Hypertensive children showed significantly increased serum and urine NGAL concentration vs controls. Urine RBP was significantly higher in the study group vs controls. A positive correlation was found between urine NGAL and the index of mean systolic BP measured in ABPM, between urine IL-18 and the index of office diastolic BP, between serum NGAL and ACR, and between urine NGAL concentration and serum HDL.

CONCLUSION

In children with primary hypertension, increased serum and urine NGAL may reflect kidney injury earlier than typical markers of hypertensive nephropathy.

Inflammasome activation of IL-18 results in endothelial progenitor cell dysfunction in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease with heterogeneous manifestations including severe organ damage and vascular dysfunction leading to premature atherosclerosis. IFN-α has been proposed to have an important role in the development of lupus and lupus-related cardiovascular disease, partly by repression of IL-1 pathways leading to impairments in vascular repair induced by endothelial progenitor cells (EPCs) and circulating angiogenic cells (CACs). Counterintuitively, SLE patients also display transcriptional upregulation of the IL-1β/IL-18 processing machinery, the inflammasome. To understand this dichotomy and its impact on SLE-related cardiovascular disease, we examined cultures of human and murine control or lupus EPC/CACs to determine the role of the inflammasome in endothelial differentiation. We show that caspase-1 inhibition improves dysfunctional SLE EPC/CAC differentiation into mature endothelial cells and blocks IFN-α-mediated repression of this differentiation, implicating inflammasome activation as a crucial downstream pathway leading to aberrant vasculogenesis. Furthermore, serum IL-18 levels are elevated in SLE and correlate with EPC/CAC dysfunction. Exogenous IL-18 inhibits endothelial differentiation in control EPC/CACs and neutralization of IL-18 in SLE EPC/CAC cultures restores their capacity to differentiate into mature endothelial cells, supporting a deleterious effect of IL-18 on vascular repair in vivo. Upregulation of the inflammasome machinery was operational in vivo, as evidenced by gene array analysis of lupus nephritis biopsies. Thus, the effects of IFN-α are complex and contribute to an elevated risk of cardiovascular disease by suppression of IL-1β pathways and by upregulation of the inflammasome machinery and potentiation of IL-18 activation.

Caloric restriction: powerful protection for the aging heart and vasculature

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in the United States. Research has shown that the majority of the cardiometabolic alterations associated with an increased risk of CVD (e.g., insulin resistance/type 2 diabetes, abdominal obesity, dyslipidemia, hypertension, and inflammation) can be prevented, and even reversed, with the implementation of healthier diets and regular exercise. Data from animal and human studies indicate that more drastic interventions, i.e., calorie restriction with adequate nutrition (CR), may have additional beneficial effects on several metabolic and molecular factors that are modulating cardiovascular aging itself (e.g., cardiac and arterial stiffness and heart rate variability). The purpose of this article is to review the current knowledge on the effects of CR on the aging of the cardiovascular system and CVD risk in rodents, monkeys, and humans. Taken together, research shows that CR has numerous beneficial effects on the aging cardiovascular system, some of which are likely related to reductions in inflammation and oxidative stress. In the vasculature, CR appears to protect against endothelial dysfunction and arterial stiffness and attenuates atherogenesis by improving several cardiometabolic risk factors. In the heart, CR attenuates age-related changes in the myocardium (i.e., CR protects against fibrosis, reduces cardiomyocyte apoptosis, prevents myosin isoform shifts, etc.) and preserves or improves left ventricular diastolic function. These effects, in combination with other benefits of CR, such as protection against obesity, diabetes, hypertension, and cancer, suggest that CR may have a major beneficial effect on health span, life span, and quality of life in humans.

Increased arterial stiffness and impaired endothelial function in nonalcoholic Fatty liver disease: a pilot study

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease both in the general and pediatric population and has been associated with increased cardiovascular risk. Arterial function and early atherosclerotic changes are markers of cardiovascular disease and independent predictors of the corresponding risk. Through a global approach, we investigated the relationships between NAFLD and functional arterial changes and early atherosclerosis.

METHODS

A total of 23 consecutive patients (mean age 55 ± 14 years, 11 males) with biopsy evidence of NAFLD and 28 control subjects matched for age, gender, body mass index, and other cardiovascular risk factors participated in the study.

RESULTS

Compared to controls, NAFLD subjects had significantly higher carotid-femoral pulse wave velocity (PWV; 8.2 ± 1.3 m/s vs. 6.9 ± 1.3 m/s, P = 0.001), higher carotid intima-media thickness (IMT; 0.79 ± 0.18 mm vs. 0.67 ± 0.13 mm, P = 0.01), and reduced flow-mediated dilatation (FMD; 1.92 ± 2.11% vs. 4.8 ± 2.43%, P < 0.001). In multivariable analysis, presence of NAFLD was an independent determinant of both PWV and FMD, whereas leptin was an independent determinant of PWV (B = 0.036, P < 0.05), and adiponectin was independently associated with FMD (B = 0.104, P < 0.05). In addition, histological activity of liver disease expressed by the global Brunt Grade was associated independently with FMD (B = -1.054, P < 0.05).

CONCLUSIONS

NAFLD is associated with arterial stiffness and endothelial dysfunction. Given the important independent prognostic role of these arterial indexes, these findings have important implications for increased cardiovascular risk in patients with NAFLD.