The role of epicardial and perivascular adipose tissue in the pathophysiology of cardiovascular disease

Carotid Extra-Media Thickness in Children: Relationships With Cardiometabolic Risk Factors and Endothelial Function

Background: Emerging evidence suggests that structural adventitial modifications and perivascular adipose tissue (PAT) may have a role in early atherogenesis. In a cohort of children and adolescents, we explored (1) the association of carotid extra-media thickness (cEMT), an ultrasound measure whose main determinants are arterial adventitia and PAT, with obesity and its cardiometabolic complications; and (2) the interplay between cEMT and endothelial function. Methods: The study participants included 286 youths (age, 6-16 years; 154 boys, and 132 girls). Anthropometric and laboratory parameters, liver ultrasound, vascular structure measures [cEMT and carotid intima-media thickness (cIMT)], endothelial function [brachial artery flow-mediated dilation (FMD)] were obtained in all subjects. Non-alcoholic fatty liver disease (NAFLD) was diagnosed in the presence of hepatic fat on ultrasonography, in the absence of other causes of liver disease. Diagnosis of metabolic syndrome (MetS) was established on the basis of three or more of the following cardiovascular disease (CVD) risk variables: abdominal obesity, high triglycerides, low high-density lipoprotein cholesterol, elevated blood pressure (BP), and impaired fasting glucose. Results: cEMT demonstrated significant associations with body-mass index (BMI) and waist circumference (WC), BP, insulin resistance, NAFLD, and inflammation. No association was found between cEMT and lipid values, and between cEMT and MetS. A stepwise multivariate linear regression analysis indicated that WC (β coefficient, 0.35; P < 0.0001) was the only determinant of cEMT, independently of other major cardiometabolic risk factors. Further adjustment for cIMT did not significantly alter this association. FMD was correlated to age, Tanner stage, total and abdominal obesity, BP, NAFLD, and cEMT. The association between FMD and cEMT was independent of age, sex, Tanner stage, WC, and BMI (β coefficient, -0.14; P = 0.027). After controlling for CVD risk factors and basal brachial artery diameter, cEMT remained associated with FMD (β coefficient, -0.11; P = 0.049). Conclusions: In youths, cEMT is associated with abdominal fat, a well-established body fat depot with important implications for cardiovascular diseases. Furthermore, cEMT is related to FMD, suggesting that arterial adventitia and PAT may be involved in the early changes in endothelial function.

Associations between Vaspin Levels and Coronary Artery Disease

The relationship between serum vaspin levels and metabolic or coronary artery disease is currently of interest for researchers. Although adipokine concentrations have been shown to be increased significantly in atherosclerotic lesions, the role adipokines in the atherosclerotic process remains to be elucidated. Vaspin is a new biological marker associated with obesity and impaired insulin sensitivity. Plasma vaspin concentration has been shown to correlate with the severity of coronary artery disease. Vascular inflammation triggered by vaspin inhibits atherogenesis by suppressing macrophage foam cell formation and vascular smooth muscle cell migration and proliferation. Vaspin also contributes to plaque stabilization by increasing collagen content and reducing the intraplaque macrophage to vascular smooth muscle cell ratio. The therapeutic goal concerning vaspin is to fight atherosclerosis and related diseases, as well as to maintain vascular health.

Effects of cold exposure revealed by global transcriptomic analysis in ferret peripheral blood mononuclear cells

Animal studies, mostly performed in rodents, show the beneficial anti-obesity effects of cold studies. This is due to thermogenic activation of brown adipose tissue (BAT), a tissue also recently discovered in adult humans. Studies in humans, however, are hampered by the accessibility of most tissues. In contrast, peripheral blood mononuclear cells (PBMC) are accessible and share the expression profile of different sets of genes with other tissues, including those that reflect metabolic responses. Ferrets are an animal model physiologically closer to humans than rodents. Here, we investigated the effects on ferrets of one-week acclimation to 4 °C by analysing the PBMC transcriptome. Cold exposure deeply affected PBMC gene expression, producing a widespread down-regulation of genes involved in different biological pathways (cell cycle, gene expression regulation/protein synthesis, immune response, signal transduction, and genes related to extracellular matrix/cytoskeleton), while thermogenic and glycogenolysis-related processes were increased. Results obtained in PBMC reflected those of adipose tissue, but hardly those of the liver. Our study, using ferret as a model, reinforce PBMC usefulness as sentinel biological material for cold-exposure studies in order to deepen our understanding of the general and specific pathways affected by cold acclimation. This is relevant for future development of therapies to be used clinically.

Epicardial Fat Volume Improves the Prediction of Obstructive Coronary Artery Disease Above Traditional Risk Factors and Coronary Calcium Score

BACKGROUND

Recent studies have demonstrated the tremendous potential of epicardial fat volume (EFV) to predict obstructive coronary artery disease. We aimed to develop a new model to estimate pretest probability of obstructive coronary artery disease using traditional risk factors with coronary calcium score and EFV and compare it with proposed models in Chinese patients who underwent coronary computed tomography angiography.

METHODS

The new models were derived from 5743 consecutive patients using multivariate logistic regression and validated in an internal cohort using invasive coronary angiography as the outcome and an external cohort with clinical outcome data. Hosmer-Lemeshow goodness-of-fit test, area under the receiver operating characteristic curve, integrated discrimination improvement and net reclassification improvement were calculated to validate and compare the performance of models.

RESULTS

EFV improved prediction above conventional risk factors and coronary calcium score (area under the receiver operating characteristic curve increased from 0.856 to 0.874, integrated discrimination improvement 0.0487, net reclassification improvement 0.1181, P<0.0001 for all). The final model included 5 predictors: age, sex, symptom, coronary calcium score, and EFV. Good internal validation and external validation of the new model were achieved, with positive net reclassification improvement and integrated discrimination improvement, excellent area under the receiver operating characteristic curve and favorable calibration. Further, the new model demonstrated a better prediction of clinical outcome, resulting in a more cost-effective risk stratification to optimize decision-making of downstream diagnosis and treatment.

CONCLUSIONS

Addition of EFV to conventional risk factors and coronary calcium score offered a more accurate and effective estimation for pretest probability of obstructive coronary artery disease, which may help to improve initial management of stable chest pain.

Relationship between epicardial adipose tissue and coronary vascular function in patients with suspected coronary artery disease and normal myocardial perfusion imaging

Aims

We evaluated the relationship between epicardial adipose tissue (EAT) and coronary vascular function assessed by rubidium-82 (82Rb) positron emission tomography/computed tomography (PET/CT) in patients with suspected coronary artery disease (CAD).

Methods and results

The study population included 270 patients with suspected CAD and normal myocardial perfusion at stress–rest 82Rb PET/CT. Coronary artery calcium (CAC) score and EAT volume were measured. Absolute myocardial blood flow (MBF) was computed in mL/min/ from the dynamic rest and stress imaging. Myocardial perfusion reserve (MPR) was defined as the ratio of hyperaemic to baseline MBF and it was considered reduced when <2. MPR was normal in 177 (65%) patients and reduced in 93 (35%). Patients with impaired MPR were older (P < 0.001) and had higher CAC score values (P = 0.033), EAT thickness (P = 0.009), and EAT volume (P < 0.001). At univariable logistic regression analysis, age, heart rate reserve (HRR), CAC score, EAT thickness, and EAT volume resulted significant predictors of reduced MPR, but only age (P = 0.002), HRR (P = 0.021), and EAT volume (P = 0.043) were independently associated with reduced MPR, at multivariable analysis. In patients with CAC score 0 (n = 114), a significant relation between EAT volume and MPR (P = 0.014) was observed, while the relationship was not significant (P = 0.21) in patients with CAC score >0 (n = 156).

Conclusion

In patients with suspected CAD and normal myocardial perfusion, EAT volume predicts hyperaemic MBF and reduced MPR, confirming that visceral pericardium fat may influence coronary vascular function. Thus, EAT evaluation has a potential role in the early identification of coronary vascular dysfunction.

Relationship between epicardial and perivascular fatty tissue and adipokine-cytokine level in coronary artery disease patients

The aim of this study was to determine the relationship between the thickness of epicardial adipose tissue (EAT) and perivascular adipose tissue (PVAT) and the adipokine-cytokine profile of patients with coronary heart disease, which can be of significant importance for predicting the course of cardiovascular disease (CVD). Eighty-four patients with CVD were assessed and divided into two groups based on the presence of visceral obesity (VO). In patients with VO, the thickness of the epicardial deposits of the left and right ventricles were 1.75 and 1.43 times greater, respectively, than in patients without VO. For patients with VO, the prevalence of the volume of the left anterior descending artery was 10% higher, and the middle third of the envelope artery was 28% higher, when compared to patients without VO. When evaluating inflammatory status, it was established that the concentration of tumor necrosis factor-α, interleukin (IL)-1β, and leptin in the blood serum of patients with VO exceeded the values of patients without VO. The level of anti-inflammatory IL-10 was 2-times lower in patients with VO. The findings of this study show that increased EAT and PVAT are independent risk factors of CVD, as well as a possible model for the assessment of drug effectiveness for CVD.

Non-contrast cardiac CT-based quantitative evaluation of epicardial and intra-thoracic fat in healthy, recently menopausal women: Reproducibility data from the Kronos Early Estrogen Prevention Study

BACKGROUND

Cardiac fat is emerging as an important parameter for cardiovascular risk stratification. Accurate and reproducible volumetric measurements can facilitate in the serial assessment of cardiac fat by computed tomography (CT). We assessed the intra- and inter-observer variability of cardiac fat volumetric measurements using a semi-automated CT software.

METHODS

We used non-contrast coronary calcium CT scans to quantify epicardial and intra-thoracic fat volumes. Two expert readers analyzed baseline and follow up CT scans of 45 subjects by using a semi-automated CT software (QFAT 2.0, Cedars Sinai-Medical Center). Correlation and Bland-Altman analysis was performed for both intra- and inter-observer comparisons for each cardiac fat type.

RESULTS

The intra-observer correlation coefficients ranged between 0.86 to 0.99 and 0.87 to 0.99 for epicardial (median fat per reader (cm³) 20.9 to 25.7) and intra-thoracic (median fat per reader (cm³) 27.1 to 31.6) fat volumes respectively, with no significant differences between individual data points (all p > 0.38). The inter-observer correlation coefficient was 0.99 (p < 0.0001 for correlation) for both epicardial and intra-thoracic fat. By Bland-Altman analysis for epicardial fat measurements, mean difference of intra-observer was 0.90 cm³ with 95% confidence intervals (0.22,1.7) and -1.8 cm³ for inter-observer, with 95% CI (-2.9, -0.69). Bland-Altman plots for intra-thoracic fat measurements were similarly impressive for both inter- and intra-observer reads.

CONCLUSIONS

Our data showed that measuring epicardial and intra-thoracic fat volumes by CT using a semi-automated software has excellent intra-observer and inter-observer reliability. Cardiac fat volumes can be obtained easily and reproducibly from routine calcium scoring scans and may help in assessing cardiovascular risk.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT00154180; Keywords: Epicardial fat volume; intra-thoracic fat volume; computed tomography; intra-observer; inter-observer.

B-type natriuretic peptide levels and benign adiposity in obese heart failure patients

Obesity is a major risk factor for the development of chronic heart failure (CHF) and does not only pose diagnostic challenges, but also has prognostic implications for these patients. Paradoxically, obese patients with CHF have a better prognosis than thinner individuals. In recent years, it has been demonstrated that the adipose tissue, even in patients with HF, is not always detrimental, and that obesity may coexist with a phenotype of benign adiposity without systemic metabolic abnormalities. Experimental data have shown that natriuretic peptides (NPs), and in particular brain natriuretic peptide (BNP), play a major role in the communication of the heart with the adipose tissue. Body fat distribution and adipose tissue function show a large degree of heterogeneity among depots and may explain the complex relationship between NPs and body fat. NPs can affect both the quality and the behaviour of fatty tissue, promoting a healthy adipocyte phenotype, and can favourably affect body fat metabolism. In this article, we review the existing literature on the bidirectional effects of BNP and adipose tissue in HF and highlight the complexity of this relationship.

The adipo-fibrokine activin A is associated with metabolic abnormalities and left ventricular diastolic dysfunction in obese patients

Aims

Left ventricular diastolic dysfunction (LVDD) is common in obese subjects, and a relationship between epicardial adipose tissue (EAT), increased adipocytokines, and cardiovascular diseases has been reported. This study sought to examine as to whether the adipo‐fibrokine activin A is a link between increased EAT, the metabolic syndrome (MetS), and LVDD in severely obese subjects.

Methods and results

In 236 obese subjects (ø body mass index 39.8 ± 7.9 kg/m²) with a variable degree of the MetS and in 60 healthy non‐obese controls (ø body mass index 24.8 ± 3.4 kg/m²), serum activin A levels were measured and correlated with parameters of the MetS, epicardial fat thickness (EFT), and echocardiographic parameters of LVDD. Activin A levels were higher in obese than in non‐obese subjects (362 ± 124 vs. 301 ± 94 pg/mL, P = 0.0004), increased with the number of MetS components (from 285 ± 82 with no MetS component, 323 ± 94 with one or two MetS components, to 403 ± 131 pg/mL with ≥3 MetS components, P < 0.0001) and correlated with EFT (r = 0.41, P < 0.001). Furthermore, activin A levels were related to several parameters of LVDD [e.g. left atrial size (382 ± 117 vs. 352 125 pg/mL, P = 0.024), E/e′ (394 ± 108 vs. 356 ± 127 pg/mL, P = 0.005)]. LVDD was highest in MetS obese subjects with high EFT (44.3%) compared with MetS obese subjects with low EFT (27.0%), non‐MetS obese subjects with high EFT (24.2%), and non‐MetS obese subjects with low EFT (10.6%, P < 0.0001).

Conclusions

In severe obesity, activin A was significantly related to EFT, MetS, and LVDD, implicating MetS‐related alterations in the secretory profile of EAT in the pathogenesis of obesity‐related heart disease.

Cellular characterization of human epicardial adipose tissue: highly expressed PAPP-A regulates insulin-like growth factor I signaling in human cardiomyocytes

Little is known about the cellular biology of fat surrounding the human heart. In this study, we obtained paired samples of epicardial fat, the visceral fat depot attached to the heart, and subcutaneous skin fat from patients undergoing open heart surgery to test the hypothesis that human epicardial fat cells differentially express bioactive molecules that have the potential to affect cardiac function. First, we characterized the free fatty acids (FFAs), adipocytokines, and growth factors secreted by isolated adipocytes and preadipocytes in cell culture. There was little to distinguish the fat cell secretory products in terms of FFAs and adipocytokines. The most striking finding was that preadipocytes from epicardial adipose tissue expressed high levels of pregnancy-associated plasma protein-A (PAPP-A), a novel metalloproteinase that enhances local insulin-like growth factor (IGF) action through cleavage of inhibitory IGF binding protein-4 (IGFBP-4). PAPP-A levels were 15-fold higher in conditioned medium from epicardial preadipocytes than from subcutaneous preadipocytes (P < 0.0001). PAPP-A was not expressed in mature adipocytes. Next we determined whether PAPP-A could affect IGF-I signaling in a human cardiomyocyte cell line. IGF-I activated receptor-mediated auto-phosphorylation, and this was blocked by wild-type and protease-resistant IGFBP-4. Addition of PAPP-A induced cleavage of wild-type, but not protease-resistant, IGFBP-4 thereby restoring IGF-I action. A proteolytically defective PAPP-A had no effect. IGF-I receptor-mediated signaling through the phosphatidylinositol 3-kinase pathway was similarly inhibited by IGFBP-4 and restored by PAPP-A. Thus, human epicardial fat cells differentially express PAPP-A, which has the potential to affect IGF signaling in the heart.

Epicardial fat tissue in patients with diabetes mellitus: a systematic review and meta-analysis

Background

Epicardial fat tissue (EFT) is the visceral fat distributed along the coronary arteries between the pericardium and the myocardium. Increases in EFT are closely related to the occurrence of diabetes mellitus (DM) and cardiovascular disease. To further understand the link between EFT and DM, we conducted a meta-analysis of the relevant literature.

Methods

We systematically searched electronic databases for studies on EFT performed in DM patients and published up to 30 September 2018. We included data on EFT in a DM patient group and a non-DM control group. We then assessed the effect of DM on EFT by meta-analysis and trial sequential analysis (TSA). All statistical analyses were performed using Stata 12.0 and TSA software.

Results

A total of 13 studies (n = 1102 patients) were included in the final analysis. Compared with the control group, DM patients had significantly higher EFT (SMD: 1.23; 95% CI 0.98, 1.48; P = 0.000; TSA-adjusted 95% CI 0.91, 2.13; P < 0.0001). The TSA indicated that the available samples were sufficient and confirmed that firm evidence was reached. According to the regression analysis and subgroup analyses, DM typing, EFT ultrasound measurements, total cholesterol (TC) and triglyceride (TG) levels were confounding factors that significantly affected our results.

Conclusions

Our meta-analysis suggests that the amount of EFT is significantly higher in DM patients than in non-DM patients.

Adipose tissues of MPC1± mice display altered lipid metabolism-related enzyme expression levels

Mitochondrial pyruvate carrier 1 (MPC1) is a component of the MPC1/MPC2 heterodimer that facilitates the transport of pyruvate into mitochondria. Pyruvate plays a central role in carbohydrate, fatty, and amino acid catabolism. The present study examined epididymal white adipose tissue (eWAT) and intrascapular brown adipose tissue (iBAT) from MPC1^± mice following 24 weeks of feeding, which indicated low energy accumulation as evidenced by low body and eWAT weight and adipocyte volume. To characterize molecular changes in energy metabolism, we analyzed the transcriptomes of the adipose tissues using RNA-Sequencing (RNA-Seq). The results showed that the fatty acid oxidation pathway was activated and several genes involved in this pathway were upregulated. Furthermore, qPCR and western blotting indicated that numerous genes and proteins that participate in lipolysis were also upregulated. Based on these findings, we propose that the energy deficiency caused by reduced MPC1 activity can be alleviated by activating the lipolytic pathway.

Fatty Acid Composition in Various Types of Cardiac Adipose Tissues and Its Relation to the Fatty Acid Content of Atrial Tissue

Diet, with its content of various types of fatty acids (FAs), is of great importance for cellular function. Adipose tissue (AT) serves as a storage for dietary FAs, but after appropriate activation it may also offer important biological properties, e.g., by releasing adipokines and cytokines to the surrounding milieu. Such effects may depend on the diet and type of FA involved. Similarly, the composition of FAs in the heart is also likely to be important for cardiac function. We investigated samples of epicardial adipose tissue (EAT), pericardial adipose tissue (PAT), subcutaneous adipose tissue (SCAT), and tissue from the right atrial appendage to compare the FA compositions in patients undergoing elective cardiac surgery. Minor differences among AT compartments were found, while the comparison of atrial tissue and EAT showed major differences in saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and n-3 and n-6 polyunsaturated fatty acids (PUFAs). These findings may be of importance for understanding biological availability, dietary effects, and the effects of FAs on the heart.

Evaluation of Epicardial Fat Thickness in Young Patients With Embolic Stroke of Undetermined Source

OBJECTIVES

Epicardial adipose tissue is metabolically active and is an important predictor of metabolic and cardiovascular diseases. This study investigated the echocardiographic epicardial adipose tissue measurement in young patients with embolic stroke of undetermined source (ESUS).

MATERIALS AND METHODS

We studied 77 volunteers, including 40 patients with ESUS (mean age 43±8 y, 16 female patients) and 37 healthy subjects (mean age 38±7 y, 20 female subjects). All necessary biochemical parameters were analyzed, and epicardial fat thickness (EFT) was measured by echocardiography in all subjects. Additional related diagnostic work-up was conducted in each patient, according to the patients' clinical presentation.

RESULTS

The patients with ESUS had a significantly higher EFT than the control group (5.51±0.82 vs. 3.96±0.51; P<0.01). Furthermore, there was a positive correlation between EFT and serum C-reactive protein levels (r=0.284; P<0.05). As an optimal cut-off point, a high-risk EFT value of 4.6 mm was determined to predict ESUS, with an 87.5% sensitivity and an 81.1% specificity.

CONCLUSION

We found that echocardiographic EFT was significantly higher in young patients with ESUS than in healthy individuals. Increased EFT might be a novel risk factor in these patients.

Adipogenic potential of perivascular adipose tissue preadipocytes is improved by coculture with primary adipocytes

Perivascular adipose tissue (PVAT) has the capacity to secrete vasoactive mediators with the potential to regulate vascular function. Given its location adjacent to the vasculature, PVAT dysfunction may be part of the pathophysiology of cardiovascular diseases. To study the mechanisms of PVAT dysfunction, several adipogenic models have been proposed. However, these approaches do not adequately reflect PVAT adipocyte phenotypes variability that depends on their anatomical location. Despite PVAT importance in modulating vascular function, to date, there is not a depot-specific adipogenic model for PVAT adipocytes. We present a model that uses coculturing of PVAT stromal vascular fraction derived preadipocytes with primary adipocytes isolated from the same PVAT. Preadipocytes were isolated from thoracic aorta PVAT and mesenteric resistance artery PVAT (mPVAT). Upon confluency, cells were induced to differentiate for 7 and 14 days using a standard protocol (SP) or standard protocol cocultured with primary adipocytes isolated from the same adipose depots (SPA) for 96, 120, and 144 h. SPA reduced the time for differentiation of stromal vascular fraction derived preadipocytes and increased their capacity to store lipids compared with SP as indicated by lipid accumulation, lipolytic responses, gene marker profile expression, and adiponectin secretion. The coculture system improved adipogenesis efficiency by enhancing lipid accumulation and reducing the time of induction, therefore, is a more efficient method compared to SP alone.

Effects of antidiabetic drugs on epicardial fat

Epicardial adipose tissue is defined as a deposit of adipocytes with pathophysiological properties similar to those of visceral fat, located in the space between the myocardial muscle and the pericardial sac. When compared with subcutaneous adipose tissue, visceral adipocytes show higher metabolic activity, lipolysis rates, increased insulin resistance along with more steroid hormone receptors. The epicardial adipose tissue interacts with numerous cardiovascular pathways via vasocrine and paracrine signalling comprised of pro- and anti-inflammatory cytokines excretion. Both the physiological differences between the two tissue types, as well as the fact that fat distribution and phenotype, rather than quantity, affect cardiovascular function and metabolic processes, establish epicardial fat as a biomarker for cardiovascular and metabolic syndrome. Numerous studies have underlined an association of altered epicardial fat morphology, type 2 diabetes mellitus (T2DM) and adverse cardiovascular events. In this review, we explore the prospect of using the epicardial adipose tissue as a therapeutic target in T2DM and describe the underlying mechanisms by which the antidiabetic drugs affect the pathophysiological processes induced from adipose tissue accumulation and possibly allow for more favourable cardiovascular outcomes though epicardial fat manipulation.

SFRP5 serves a beneficial role in arterial aging by inhibiting the proliferation, migration and inflammation of smooth muscle cells

Secreted frizzled-related protein 5 (SFRP5) is one of the anti-inflammatory adipokines secreted from white adipose tissue. However, little is known about the effect of SFRP5 on the cardiovascular system. The aim of the present study was to determine the effect of SFRP5 on smooth muscle cell (SMC) proliferation, migration and inflammation. The plasma levels of SFRP5 were evaluated in a cohort‑based elderly population using ELISA, and the expression of SFRP5 in Sprague‑Dawley rat aortas was detected using immunohistochemistry. SMC proliferation and migration were evaluated in vitro using 5‑ethynyl‑2'‑deoxyuridine cell proliferation and wound‑healing assays, respectively, while reactive oxygen species (ROS) production and cell signaling were assessed using a 2',7'‑dichlorodihydrofluorescein diacetate assay and immunoblotting, respectively. The results revealed that plasma levels of SFRP5 were positively correlated with age in the elderly Chinese cohort. Similarly, aorta SFRP5 expression was significantly higher in 15‑month‑old rats compared with 6‑month‑old rats. In vitro, SFRP5 significantly inhibited rat aortic SMC proliferation and migration that were induced by platelet‑derived growth factor (PDGF)‑BB, as well as inhibiting ROS generation. Compared with the effect of PDGF‑BB on SMCs, SFRP5 at 100 and 200 ng/ml significantly decreased SMC proliferation by 31.5 and 34.8%, respectively (P<0.05). SFRP5 at 100 and 200 ng/ml also inhibited the migration of SMCs by 24.9 and 28.4%, respectively, when compared with the effects of PDGF‑BB. SFRP5 attenuated the PDGF‑BB‑induced expression of β‑catenin and proliferating cell nuclear antigen, while p38 phosphorylation was significantly attenuated. Together, the present results suggested that SFRP5 may inhibit SMC proliferation, migration and inflammation by suppressing the Wnt/β‑catenin and p38/mitogen‑activated protein kinase signaling pathways.

The measurement of both carotid intima-media thickness and epicardial adipose tissue thickness in children with epilepsy receiving antiepileptic drug therapy

OBJECTIVE

The aim of this study was to evaluate the carotid intima-media thickness together with the thickness of the epicardial adipose tissue in patients receiving antiepileptic drug therapy and to investigate the presence of increased cardiovascular risk in these patients.

METHODS

The study included a total of 52 patients comprising 32 males and 20 females who were diagnosed as having epilepsy and who were using one or more antiepileptic drugs. The control group consisted of 34 healthy individuals comprising 16 males and 18 females. The individuals selected for the study group were requested to go to the hospital after overnight fasting. After blood sampling for serum lipid value, the carotid intima-media thickness was measured with high resolution B-mode ultrasonography and epicardial adipose tissue thickness with echocardiography in the patients and the control group subjects.

RESULTS

The carotid intima-media thickness was determined as 0.47 ± 0.05 mm in the patient group and 0.44 ± 0.04 mm in the control group (p = 0.028). The carotid intima-media thickness was measured as 0.45 ± 0.05 mm in patients with epilepsy taking monotherapy and 0.49 ± 0.04 mm in those taking polytherapy (p = 0.003). The epicardial adipose tissue thickness was determined as 3.42 ± 0.09 mm in the patient group and 1.72 ± 0.90 mm in the control group (p = 0.000). The epicardial adipose tissue thickness was measured as 3.16 ± 0.87 mm in patients with epilepsy taking monotherapy and 3.77 ± 0.83 mm in those taking polytherapy (p = 0.041).

CONCLUSIONS

It was determined that carotid intima-media thickness and epicardial adipose tissue thickness were significantly high in children with epilepsy taking long-term antiepileptic drugs. These results demonstrate that these patients could be at increased risk of the development of cardiovascular complications. There is a need for more extensive studies on this subject.

Epicardial adipose tissue as a metabolic transducer: role in heart failure and coronary artery disease

Obesity and diabetes are strongly associated with metabolic and cardiovascular disorders including dyslipidemia, coronary artery disease, hypertension, and heart failure. Adipose tissue is identified as a complex endocrine organ, which by exerting a wide array of regulatory functions at the cellular, tissue and systemic levels can have profound effects on the cardiovascular system. Different terms including "epicardial," "pericardial," and "paracardial" have been used to describe adipose tissue deposits surrounding the heart. Epicardial adipose tissue (EAT) is a unique and multifaceted fat depot with local and systemic effects. The functional and anatomic proximity of EAT to the myocardium enables endocrine, paracrine, and vasocrine effects on the heart. EAT displays a large secretosome, which regulates physiological and pathophysiological processes in the heart. Perivascular adipose tissue (PVAT) secretes adipose-derived relaxing factor, which is a "cocktail" of cytokines, adipokines, microRNAs, and cellular mediators, with a potent effect on paracrine regulation of vascular tone, vascular smooth muscle cell proliferation, migration, atherosclerosis-susceptibility, and restenosis. Although there are various physiological functions of the EAT and PVAT, a phenotypic transformation can lead to a major pathogenic role in various cardiovascular diseases. The equilibrium between the physiological and pathophysiological properties of EAT is very delicate and susceptible to the influences of intrinsic and extrinsic factors. Various adipokines secreted from EAT and PVAT have a profound effect on the myocardium and coronary arteries; targeting these adipokines could be an important therapeutic approach to counteract cardiovascular disease.

White blood cells count as an indicator to identify whether obesity leads to increased risk of type 2 diabetes

AIMS

Obesity promotes a variety of poor health outcomes, including type 2 diabetes (T2D). However, not all obese people are at an elevated risk of T2D. Obesity is closely linked to chronic inflammation. In addition, inflammation is an important contributor to T2D via the processes of insulin resistance and islet β-cell failure. Therefore, we hypothesize that white blood cells (WBC) count, a marker of subclinical inflammation, can be used as an indicator to identify whether or not obesity leads to increased risk of T2D. To investigate this hypothesis, we conducted a prospective cohort study in a general population.

METHODS

A total of 47,678 subjects were followed up from 2007 to 2016. WBC count was determined by automated hematology analyzer. T2D and obesity were defined in accordance with the criteria of the World Health Organization. Adjusted Cox proportional hazards regression models were used to assess relationships between obese status, WBC count and the incidence of T2D.

RESULTS

During the approximately ∼9-year follow-up period (median duration of follow-up: 3.48y), 1463 subjects developed T2D. In the final multivariate model, the hazard ratios (95% confidence interval) of T2D for obese participants with elevated WBC count, non-obese participants with elevated WBC count, and non-obese participants with low WBC count, when compared to obese participants with low WBC count were: 1.22(1.03-1.44), 1.37(1.12-1.66) and 0.99(0.83-1.20), respectively.

CONCLUSIONS

This study demonstrated that WBC count can be used as an indicator to identify whether or not obesity leads to increased risk of T2D.

Interplay between epicardial adipose tissue, metabolic and cardiovascular diseases

Cardiovascular disease is the primary cause of death in obese and diabetic patients. In these groups of patients, the alterations of epicardial adipose tissue (EAT) contribute to both vascular and myocardial dysfunction. Therefore, it is of clinical interest to determine the mechanisms by which EAT influences cardiovascular disease. Two key factors contribute to the tight intercommunication among EAT, coronary arteries and myocardium. One is the close anatomical proximity between these tissues. The other is the capacity of EAT to secrete cytokines and other molecules with paracrine and vasocrine effects on the cardiovascular system. Epidemiological studies have demonstrated that EAT thickness is associated with not only metabolic syndrome but also atherosclerosis and heart failure. The evaluation of EAT using imaging modalities, although effective, presents several disadvantages including radiation exposure, limited availability and elevated costs. Therefore, there is a clinical interest in EAT as a source of new biomarkers of cardiovascular and endocrine alterations. In this review, we revise the mechanisms involved in the protective and pathological role of EAT and present the molecules released by EAT with greater potential to become biomarkers of cardiometabolic alterations.

Microenvironment of Immune Cells Within the Visceral Adipose Tissue Sensu Lato vs. Epicardial Adipose Tissue: What Do We Know?

The chronic low-grade inflammation of the visceral adipose tissue is now fully established as one of the main contributors to metabolic disorders such as insulin resistance, subsequently leading to metabolic syndrome and other associated cardiometabolic pathologies. The orchestration of immune response and the "ratio of responsibility" of different immune cell populations have been studied extensively over the last few years within the visceral adipose tissue in general sense (sensu lato). However, it is essential to clearly distinguish different types of visceral fat distribution. Visceral adipose tissue is not only the classical omental or epididymal depot, but includes also specific type of fat in the close vicinity to the myocardium-the epicardial adipose tissue. Disruption of this type of fat during obesity was found to have a unique and direct influence over the cardiovascular disease development. Therefore, epicardial adipose tissue and other types of visceral adipose tissue depots should be studied separately. The purpose of this review is to explore the present knowledge about the morphology and dynamics of individual populations of immune cells within the visceral adipose tissue sensu lato in comparison to the knowledge regarding the epicardial adipose tissue specifically.

Dobutamine Stress Echocardiography Unmasks Early Left Ventricular Dysfunction in Asymptomatic Patients with Uncomplicated Type 2 Diabetes: A Comprehensive Two-Dimensional Speckle-Tracking Imaging Study

BACKGROUND

Discrepancies are present in the literature on resting myocardial mechanics in patients with uncomplicated type 2 diabetes mellitus (T2DM). Data are noticeably sparse regarding circumferential function and torsional mechanics. Resting deformation imaging may not be sensitive enough to detect subtle dysfunctions. The aim of this study was thus to comprehensively evaluate myocardial mechanics in patients with T2DM at rest and to investigate whether dobutamine stress echocardiography could unmask functional alterations that would remain otherwise subtle at rest.

METHODS

Forty-four patients with T2DM and 35 healthy control subjects of similar age and sex were prospectively recruited. After conventional echocardiography, myocardial mechanics was evaluated at rest and during low-dose dobutamine stress echocardiography (target heart rate, 110 beats/min).

RESULTS

Patients with T2DM presented with altered global diastolic function but preserved systolic function. Deformation imaging indexes were similar between groups at rest, but significant differences were noticed under dobutamine infusion for longitudinal strain (-21.2 ± 2.4% vs -24.2 ± 2.5%, P < .001), circumferential strain (apex, -32.3 ± 5.3% vs -36.3 ± 5.3%, P = .002; papillary muscle, -25.6 ± 3.2% vs -28.0 ± 3.6%, P = .001; base, -23.2 ± 3.6% vs -25.3 ± 3.8%, P = .03), apical (11.2 ± 4.4° vs 14.1 ± 6.3°, P = .020) and basal (-12.2 ± 3.3° vs -14.3 ± 3.9°, P = .021) rotation, and twist (21.9 ± 5.9° vs 26.8 ± 8.3°, P = .007). Multivariate analysis identified epicardial fat, dyslipidemia, and fasting glycaemia as significant contributors to the changes from rest to dobutamine.

CONCLUSIONS

These findings demonstrate the usefulness of dobutamine stress echocardiography in establishing impairments in myocardial mechanics in patients with uncomplicated T2DM. Systemic metabolic disturbances and epicardial fat act as the main contributors to the blunted response to dobutamine stress in these patients.

Association of asymptomatic target organ damage with secreted frizzled related protein 5 in the elderly: the Northern Shanghai Study

Objective

Secreted frizzled related protein 5 (SFRP5) is a novel anti-inflammatory adipokine that is implicated in metabolic and cardiovascular disease (CVD). However, little is known about the relevance of SFRP5 with asymptomatic hypertensive target organ damages (TODs). We aimed to investigate the association between SFRP5 and TOD in a large population.

Clinical trial registration

NCT02368938.

Methods

A total of 1,745 community-dwelling elderly subjects aged over 65 years from northern Shanghai were recruited in the study. Plasma SFRP5 level was measured by an enzyme-linked immunosorbent assay. Asymptomatic TODs, including left ventricular mass index, peak transmitral pulsed Doppler velocity/early diastolic tissue Doppler velocity, carotid intima–media thickness (CIMT), pulse wave velocity (PWV), estimated glomerular filtration rate, and urinary albumin–creatinine ratio were evaluated.

Results

Plasma SFRP5 level was negatively associated with body mass index, waist/hip ratio, and fasting blood glucose (all P<0.001). Men, compared with women, had lower plasma SFRP5 level (4.19 vs 5.13 ng/mL, P<0.001). Additionally, plasma SFRP5 level was lower in diabetics than in those without diabetes (4.30 vs 4.81 ng/mL, P<0.05). Furthermore, an inverse association was observed between SFRP5 and PWV and CIMT (both P<0.05). Lastly, the multivariate logistic regression analysis showed lower SFRP5 level was significantly associated with increased arterial stiffness in the elderly (odds ratio 0.83, 95% confidence interval 0.71 to 0.99 per 1 standard deviation increase, P<0.05).

Conclusion

Plasma SFRP5 level was inversely correlated with conventional cardiovascular risk factors, and low plasma SFRP5 was also significantly associated with arterial stiffening in the elderly Chinese population.

Role of Perivascular Adipose Tissue in Health and Disease

Perivascular adipose tissue (PVAT) is cushion of fat tissue surrounding blood vessels, which is phenotypically different from other adipose tissue depots. PVAT is composed of adipocytes and stromal vascular fraction, constituted by different populations of immune cells, endothelial cells, and adipose-derived stromal cells. It expresses and releases an important number of vasoactive factors with paracrine effects on vascular structure and function. In healthy individuals, these factors elicit a net anticontractile and anti-inflammatory paracrine effect aimed at meeting hemodynamic and metabolic demands of specific organs and regions of the body. Pathophysiological situations, such as obesity, diabetes or hypertension, induce changes in its amount and in the expression pattern of vasoactive factors leading to a PVAT dysfunction in which the beneficial paracrine influence of PVAT is shifted to a pro-oxidant, proinflammatory, contractile, and trophic environment leading to functional and structural cardiovascular alterations and cardiovascular disease. Many different PVATs surrounding a variety of blood vessels have been described and exhibit regional differences. Both protective and deleterious influence of PVAT differs regionally depending on the specific vascular bed contributing to variations in the susceptibility of arteries and veins to vascular disease. PVAT therefore, might represent a novel target for pharmacological intervention in cardiovascular disease. © 2018 American Physiological Society. Compr Physiol 8:23-59, 2018.

Gene expression profiling reveals heterogeneity of perivascular adipose tissues surrounding coronary and internal thoracic arteries

The internal thoracic artery (ITA) that differs from coronary artery (CA), rarely develops atherosclerosis. Understanding the mechanism underlying such a difference will help to pave a new way to the prevention and treatment of the disease. We hypothesize herein that the difference in susceptibility to atherosclerosis between CA and ITA is attributable to the heterogeneity of perivascular adipose tissues (PVATs) surrounding these two kinds of arteries, i.e. PVAT-CA and PVAT-ITA. We isolated PVAT from eight patients of coronary heart disease (CHD) and four non-CHD patients. Gene expression patterns were analyzed by using Agilent whole gene expression profile chips. By comparison between PVAT-CA and PVAT-ITA, we identified 2053 differentially expressed genes, of which 1042 were up-regulated and 1011 were down-regulated, respectively, in CHD group. KEGG pathway and gene ontology (GO) analysis revealed that those differentially expressed genes related to inflammation, lipid metabolism and myocardial processes were particularly noted in the CHD group, but not in non-CHD. Several selected genes, including interleukin-1β (IL-1β), interleukin-6 (IL-6), Toll-like receptor 2 (TLR2), Toll-interleukin 1 receptor domain containing adaptor protein (TIRAP), serum amyloid A2 (SAA2), and Leptin were validated by real-time PCR analysis. The results showed that the expression levels of IL-1β, IL-6, and Leptin were significantly higher in PVAT-CA than in PVAT-ITA (P = 0.016, 0.021, and 0.018) in CHD patients. Levels of TLR2, TIRAP, and SAA2 expression were also higher in PVAT-CA, however no significant difference was observed (P = 0.054, 0.092, and 0.058). In conclusion, our findings demonstrate differential gene expression patterns between PVAT-CA and PVAT-ITA, revealing a high heterogeneity in PVAT. Particularly, those genes related to inflammation, lipid metabolism and myocardial processes are differentially expressed in PVAT-CA and PVAT-ITA in CHD patients, suggesting an important role of PVAT in the development of coronary atherosclerosis.

Adipokines at the crossroad between obesity and cardiovascular disease

Obesity, and especially excessive visceral adipose tissue accumulation, is considered as a low-grade inflammatory state that is responsible for adipocyte dysfunction and associated metabolic disorders. Adipose tissue displays endocrine functions by releasing pro- or antiinflammatory bioactive molecules named adipokines. An altered expression of these molecules, provoked by obesity or adipocyte dysregulation, contributes to major metabolic diseases such as insulin resistance and type 2 diabetes mellitus that are important risk factors for cardiovascular disease. However, obesity is also characterised by the expansion of perivascular adipose tissue that acts locally via diffusion of adipokines into the vascular wall. Local inflammation within blood vessels induced by adipokines contributes to the onset of endothelial dysfunction, atherosclerosis and thrombosis, but also to vascular remodelling and hypertension. A fast expansion of obesity is expected in the near future, which will rapidly increase the incidence of these cardiovascular diseases. The focus of this review is to summarise the link between metabolic and cardiovascular disease and discuss current treatment approaches, limitations and future perspectives for more targeted therapies.

Cold exposure down-regulates immune response pathways in ferret aortic perivascular adipose tissue

Perivascular adipose tissue (PVAT) surrounds blood vessels and releases paracrine factors, such as cytokines, which regulate local inflammation. The inflammatory state of PVAT has an important role in vascular disease; a pro-inflammatory state has been related with atherosclerosis development, whereas an anti-inflammatory one is protective. Cold exposure beneficially affects immune responses and, could thus impact the pathogenesis of cardiovascular diseases. In this study, we investigated the effects of one-week of cold exposure at 4°C of ferrets on aortic PVAT (aPVAT) versus subcutaneous adipose tissue. Ferrets were used because of the similarity of their adipose tissues to those of humans. A ferret-specific Agilent microarray was designed to cover the complete ferret genome and global gene expression analysis was performed. The data showed that cold exposure altered gene expression mainly in aPVAT. Most of the regulated genes were associated with cell cycle, immune response and gene expression regulation, and were mainly down-regulated. Regarding the effects on immune response, cold acclimation decreased the expression of genes involved in antigen recognition and presentation, cytokine signalling and immune system maturation and activation. This immunosuppressive gene expression pattern was depot-specific, as it was not observed in the inguinal subcutaneous depot. Interestingly, this depression in immune response related genes was also evident in peripheral blood mononuclear cells (PBMC). In conclusion, these results reveal that cold acclimation produces an inhibition of immune response-related pathways in aPVAT, reflected in PBMC, indicative of an anti-inflammatory response, which can potentially be exploited for the enhancement or maintenance of cardiovascular health.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Adiponectin improves endothelial function in mesenteric arteries of rats fed a high-fat diet: role of perivascular adipose tissue

BACKGROUND AND PURPOSE

Adiponectin, the most abundant peptide secreted by adipocytes, is involved in the regulation of energy metabolism and vascular physiology. Here, we have investigated the effects of exogenous administration of adiponectin on metabolism, vascular reactivity and perivascular adipose tissue (PVAT) of mesenteric arteries in Wistar rats fed a high-fat diet.

EXPERIMENTAL APPROACH

The effects of adiponectin on NO-dependent and independent vasorelaxation were investigated in isolated mesenteric arteries from 12-month-old male Wistar rats (W12m) fed a high-fat diet (HFD) for 4 months and compared with those from age-matched rats given a control diet. Adiponectin ((96 μg·day-1 ) was administered by continuous infusion with a minipump, implanted subcutaneously, for 28 days.

KEY RESULTS

Chronic adiponectin treatment reduced body weight, total cholesterol, free fatty acids, fasting glucose and area under the curve of intraperitoneal glucose tolerance test, compared with HFD rats. It also normalized NO-dependent vasorelaxation increasing endothelial NO synthase (eNOS) phosphorylation in mesenteric arteries of HFD rats. In PVAT from aged (W12m) and HFD rats there was increased expression of chemokines and pro-inflammatory adipokines, the latter being important contributors to endothelial dysfunction. Infusion of adiponectin reduced these changes.

CONCLUSIONS AND IMPLICATIONS

Adiponectin normalized endothelial cell function by a mechanism that involved increased eNOS phoshorylation and decreased PVAT inflammation. Detailed characterization of the adiponectin signalling pathway in the vasculature and perivascular fat is likely to provide novel approaches to the management of atherosclerosis and metabolic disease.

LINKED ARTICLES

This article is part of a themed section on Molecular Mechanisms Regulating Perivascular Adipose Tissue - Potential Pharmacological Targets? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.20/issuetoc.

Role of Epicardial Adipose Tissue in Health and Disease: A Matter of Fat?

Epicardial adipose tissue (EAT) is a small but very biologically active ectopic fat depot that surrounds the heart. Given its rapid metabolism, thermogenic capacity, unique transcriptome, secretory profile, and simply measurability, epicardial fat has drawn increasing attention among researchers attempting to elucidate its putative role in health and cardiovascular diseases. The cellular crosstalk between epicardial adipocytes and cells of the vascular wall or myocytes is high and suggests a local role for this tissue. The balance between protective and proinflammatory/profibrotic cytokines, chemokines, and adipokines released by EAT seem to be a key element in atherogenesis and could represent a future therapeutic target. EAT amount has been found to predict clinical coronary outcomes. EAT can also modulate cardiac structure and function. Its amount has been associated with atrial fibrillation, coronary artery disease, and sleep apnea syndrome. Conversely, a beiging fat profile of EAT has been identified. In this review, we describe the current state of knowledge regarding the anatomy, physiology and pathophysiological role of EAT, and the factors more globally leading to ectopic fat development. We will also highlight the most recent findings on the origin of this ectopic tissue, and its association with cardiac diseases. © 2017 American Physiological Society. Compr Physiol 7:1051-1082, 2017.

Epicardial Adipose Tissue Removal Potentiates Outward Remodeling and Arrests Coronary Atherogenesis

BACKGROUND

Pericoronary epicardial adipose tissue (cEAT) serves as a metabolic and paracrine organ that contributes to inflammation and is associated with macrovascular coronary artery disease (CAD) development. Although there is a strong correlation in humans between cEAT volume and CAD severity, there remains a paucity of experimental data demonstrating a causal link of cEAT to CAD. The current study tested the hypothesis that surgical resection of cEAT attenuates inflammation and CAD progression.

METHODS

Female Ossabaw miniature swine (n = 12) were fed an atherogenic diet for 8 months and randomly allocated into sham (n = 5) or adipectomy (n = 7) groups. Both groups underwent a thoracotomy, opening of the pericardial sac, and placement of radioopaque clips to mark the proximal left anterior descending artery. Adipectomy swine underwent removal of 1 to 1.5 cm2 of cEAT from the proximal artery. After sham or adipectomy, CAD severity was assessed with intravascular ultrasonography. Swine recovered for an additional 3 months on an atherogenic diet, and CAD was assessed immediately before euthanasia. Artery sections were processed for histologic and immunohistochemical analysis.

RESULTS

Severity of CAD as assessed by percent stenosis was reduced in the adipectomy cohort compared with shams; however, plaque size remained unaltered, whereas larger plaque sizes developed in sham-operated swine. Adipectomy resulted in an expanded arterial diameter, similar to the Glagov phenomenon of positive outward remodeling. No differences in inflammatory marker expression were observed.

CONCLUSIONS

These data indicate that cEAT resection did not alter inflammatory marker expression, but arrested CAD progression through increased positive outward remodeling and arrest of atherogenesis.

Ahsan C. Hypertension in diabetes and the risk of cardiovascular disease

Hypertension (HTN) is an important risk factor for cardiovascular disease and its many manifestations. It shares pathogenic pathways with diabetes and is part of a common metabolic entity, the metabolic syndrome. When combined with diabetes, HTN has been shown to predict and promote increased risk for cardiovascular disease events over and above each risk factor alone. Of the components of this metabolic syndrome, HTN is relatively easy to diagnose and thereby more accessible for implementing preventive and treatment strategies. The recent release of Joint National Committee-8 guidelines for the treatment of HTN has fueled a debate on treatment target goals.

Perivascular adipose tissue as a regulator of vascular disease pathogenesis: identifying novel therapeutic targets

Adipose tissue (AT) is an active endocrine organ with the ability to dynamically secrete a wide range of adipocytokines. Importantly, its secretory profile is altered in various cardiovascular disease states. AT surrounding vessels, or perivascular AT (PVAT), is recognized in particular as an important local regulator of vascular function and dysfunction. Specifically, PVAT has the ability to sense vascular paracrine signals and respond by secreting a variety of vasoactive adipocytokines. Due to the crucial role of PVAT in regulating many aspects of vascular biology, it may constitute a novel therapeutic target for the prevention and treatment of vascular disease pathogenesis. Signalling pathways in PVAT, such as those using adiponectin, H₂ S, glucagon-like peptide 1 or pro-inflammatory cytokines, are among the potential novel pharmacological therapeutic targets of PVAT.

LINKED ARTICLES

This article is part of a themed section on Molecular Mechanisms Regulating Perivascular Adipose Tissue - Potential Pharmacological Targets? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.20/issuetoc.

Secretory products from epicardial adipose tissue from patients with type 2 diabetes impair mitochondrial β-oxidation in cardiomyocytes via activation of the cardiac renin-angiotensin system and induction of miR-208a

Secretory products from epicardial adipose tissue (EAT) from patients with type 2 diabetes (T2D) impair cardiomyocyte function. These changes associate with alterations in miRNA expression, including the induction of miR-208a. Recent studies suggest that activation of the cardiac-specific renin-angiotensin system (RAS) may affect cardiac energy metabolism via induction of miR-208a. This study investigated whether cardiomyocyte dysfunction induced by conditioned media (CM) from EAT-T2D involves activation of the RAS/miR-208a pathway. Therefore, primary adult rat cardiomyocytes were incubated with CM generated from EAT biopsies from patients with T2D and without T2D (ND). Exposing cardiomyocytes to CM-EAT-T2D reduced sarcomere shortening and increased miR-208a expression versus cells exposed to CM-EAT-ND or control medium. The angiotensin II receptor type 1 (AGTR1) antagonist losartan reversed these effects. Accordingly, incubation with angiotensin II (Ang II) reduced sarcomere shortening, and lowered palmitate-induced mitochondrial respiration and carnitine palmitoyltransferase 1c (CPT1c) expression in cardiomyocytes. Locked-nucleic-acid-mediated inhibition of miR-208a function reversed the detrimental effects induced by Ang II. Interestingly, Ang II levels in CM-EAT-T2D were increased by 2.6-fold after culture with cardiomyocytes. The paracrine activation of the cardiac-specific RAS by CM-EAT-T2D was corroborated by increases in the expression of AGTR1 and renin, as well as a reduction in angiotensin-converting enzyme 2 levels. Collectively, these data show that secretory products from EAT-T2D impair cardiomyocyte contractile function and mitochondrial β-oxidation via activation of the cardiac-specific RAS system and induction of miR-208a, and suggest that alterations in the secretory profile of EAT may contribute to the development of diabetes-related heart disease.

Perivascular adipose tissue alleviates inflammatory factors and stenosis in diabetic blood vessels

Adipose tissue can modulate disease processes in a depot-specific manner. However, the functional properties of perivascular adipocytes, and their influence on the pathophysiology of blood vessel walls, remain to be determined. In this study, we aimed to investigate whether perivascular adipose tissue could have an ameliorative effect on blood vessels damaged in diabetes. Using in vitro coculture, and in vivo transplantation model simulating diabetic angioplasty-induced injury, we showed that perivascular adipose tissue has an important function in protecting blood vessels from high glucose impairment. Levels of inflammatory cytokines, including intercellular cell adhesion molecule-1 and osteopontin, were markedly reduced, whereas that of endothelial nitric-oxide synthase was markedly elevated in vascular walls. These depot-specific differences in blood vessels exposed to high levels of glucose were demonstrable both in vivo, with transplanted adipose tissues, and in vitro, when vascular endothelial cells were cocultured with adipocytes. In addition, intimal hyperplasia was also decreased by transplanted perivascular adipose tissue after balloon injury combined with hyperglycemia. We conclude that perivascular adipocytes can reduce inflammation in blood vessels and promote the normal function of endothelium, which could afford a new therapeutic strategy in vascular walls damaged by diabetes.

Pregnancy-driven cardiovascular maternal miR-29 plasticity in obesity

BACKGROUND

Obesity in pregnancy (MO) is a risk factor for maternal and/or fetal cardiovascular system disorders. This study evaluated maternal CVS expression of microRNA-29 family and its target molecules in MO to test the hypotheses: CVS miR-29 concentrations are increased in pregnancy and decreased in MO.

METHODS

Non-pregnant (n=4), pregnant obese (POb, n=4), and pregnant non-obese (PnOb, n=4) baboons (Papio spp.) were studied. Maternal left ventricle (LV), left atrium (LA), and aortic arch (AA) were collected at the end of gestation. Expression of MiR-29 and elastin (ELN) mRNA were quantified.

RESULTS

LA miR-29 (a, c) expression was highest in PnOb. In the LV, miR-29b expression trended lower (P=.059) for PnOb animals. ELN mRNA expression correlated positively with miR-29b expression in AA (r=.76, P=.03).

CONCLUSION

Maternal obesity diminishes miR-29 adaptation to pregnancy. Pharmacologic, tissue-specific targeting of miRNA-29 may represent a strategy for prevention and treatment of MO complications.

Localizing factors in atherosclerosis

Atherosclerotic vascular disease is the leading cause of death worldwide. Although the entire vascular bed is constantly exposed to the same risk factors, atheromatous lesions present a distinct intra-individual pattern of localization and progression, being consistently more frequent in specific segments of the arterial vascular bed. This peculiar distribution may be related to selective sensitivity of such locations to the influence of risk factors or to histopathological and flow differences, and has relevant clinical implications, as the prognosis of the disease varies according to localization. We here review the theories that have been formulated to explain such preferential locations, as its understanding can be useful to pursue diagnostic screening strategies and focused preventive measures.

Insulin Signaling and Heart Failure

Heart failure is associated with generalized insulin resistance. Moreover, insulin-resistant states such as type 2 diabetes mellitus and obesity increases the risk of heart failure even after adjusting for traditional risk factors. Insulin resistance or type 2 diabetes mellitus alters the systemic and neurohumoral milieu, leading to changes in metabolism and signaling pathways in the heart that may contribute to myocardial dysfunction. In addition, changes in insulin signaling within cardiomyocytes develop in the failing heart. The changes range from activation of proximal insulin signaling pathways that may contribute to adverse left ventricular remodeling and mitochondrial dysfunction to repression of distal elements of insulin signaling pathways such as forkhead box O transcriptional signaling or glucose transport, which may also impair cardiac metabolism, structure, and function. This article will review the complexities of insulin signaling within the myocardium and ways in which these pathways are altered in heart failure or in conditions associated with generalized insulin resistance. The implications of these changes for therapeutic approaches to treating or preventing heart failure will be discussed.

Epicardial Adipose Tissue Contributes to the Development of Non-Calcified Coronary Plaque: A 5-Year Computed Tomography Follow-up Study

Aim: Epicardial adipose tissue (EAT) has been suggested as a contributing factor for coronary atherosclerosis based on the previous cross-sectional studies and pathophysiologic background. However, a causal relationship between EAT and the development of non-calcified coronary plaque (NCP) has not been investigated.

Methods: A total of 122 asymptomatic individuals (age, 56.0 ± 7.6 years; male, 80.3%) without prior history of coronary artery disease (CAD) or metabolic syndrome and without NCP or obstructive CAD at baseline cardiac computed tomography (CT) were enrolled. Repeat cardiac CT was performed with an interval of more than 5 years. Epicardial fat volume index (EFVi; cm³/m²) was assessed in relation to the development of NCP on the follow-up CT where the results were classified into “calcified plaque (CP),” “no plaque,” and “NCP” groups.

Results: On the follow-up CT performed with a median interval of 65.4 months, we observed newly developed NCP in 24 (19.7%) participants. Baseline EFVi was significantly higher in the NCP group (79.9 ± 30.3 cm³/m²) than in the CP group (63.7 ± 22.7 cm³/m²; P = 0.019) and in the no plaque group (62.5 ± 24.7 cm³/m²; P = 0.021). Multivariable logistic regression analysis demonstrated that the presence of diabetes (OR, 9.081; 95% CI, 1.682–49.034; P = 0.010) and the 3rd tertile of EFVi (OR, 4.297; 95% CI, 1.040–17.757; P = 0.044 compared to the 1st tertile) were the significant predictors for the development of NCP on follow-up CT.

Conclusions: Greater amount of EAT at baseline CT independently predicts the development of NCP in asymptomatic individuals.

Relationship between Regional Fat Distribution and Hypertrophic Cardiomyopathy Phenotype

Background

Hypertrophic cardiomyopathy (HCM), the most common genetic heart disease, is characterized by heterogeneous phenotypic expression. Body mass index has been associated with LV mass and heart failure symptoms in HCM. The aim of our study was to investigate whether regional (trunk, appendicular, epicardial) fat distribution and extent could be related to hypertrophy severity and pattern in HCM.

Methods

Cardiovascular magnetic resonance was performed in 32 subjects with echocardiography-based diagnosis of HCM (22M/10F, 57.2±12.6 years) characterized by predominant hypertrophy at the interventricular septum (IVS). Regional fat distribution was assessed by dual-energy X-ray absorptiometry.

Results

Gender differences were detected in maximum IVS thickness (M: 18.3±3.8 mm vs. F: 14.3±4 mm, p = 0.012), right ventricle (RV) systolic function (M: 61.3±6.7%; F: 67.5±6.3%, p = 0.048), indexed RV end-diastolic (M: 64.8±16.3 ml/m²; F: 50.7±15.5 ml/m², p = 0.04) and end-systolic volumes (M: 24.3±8.3 ml/m²; F: 16.7±7.4 ml/m², p = 0.04). After adjusting for age and gender, maximum IVS thickness was associated with truncal fat (Tr-FAT) (β = 0.43, p = 0.02), but not with either appendicular or epicardial fat. Epicardial fat resulted independently associated with NT-proBNP levels (β = 0.63, p = 0.04). Late Gadolinium Enhancement-positive subjects displayed greater maximum IVS thickness (p = 0.02), LV mass index (p = 0.015) and NT-proBNP levels (p = 0.04), but no associations with fat amount or distribution were observed.

Conclusion

Truncal, but not appendicular or epicardial fat amount, seems to be related with maximum IVS thickness, the hallmark feature in our cohort of HCM patients. Further prospective researches are needed to assess a potential causative effect of central adiposity on HCM phenotype.

Increased Epicardial Fat Thickness Correlates with Aortic Stiffness and N-Terminal Pro-Brain Natriuretic Peptide Levels in Acute Ischemic Stroke Patients

Epicardial fat, a metabolically active tissue, has emerged as a risk factor and active player in metabolic and cardiovascular diseases. We investigated epicardial fat thickness in patients who had sustained an acute ischemic stroke, and we evaluated the relationship of epicardial fat thickness with other prognostic factors. We enrolled 61 consecutive patients (age, ≥18 yr) who had sustained a first acute ischemic stroke and had been admitted to our hospital within 24 hours of the onset of stroke symptoms. The control group comprised 82 consecutive sex- and age-matched patients free of past or current stroke who had been admitted to our cardiology clinics. Blood samples were taken for measurement of N-terminal pro-brain natriuretic peptide (NT-proBNP) levels at admission. Aortic stiffness indices and epicardial fat thickness were measured by means of transthoracic echocardiography within the first 48 hours. In comparison with the control group, the patients with acute ischemic stroke had significantly higher epicardial fat thickness (4.8 ± 0.9 vs 3.8 ± 0.7 mm; P <0.001), lower aortic distensibility (2.5 ± 0.8 vs 3.4 ± 0.9 cm(2) ·dyn(-1); P <0.001) and lower aortic strain (5.5% ± 1.9% vs 6.4% ± 1.8%; P=0.003). We found a significant association between epicardial fat thickness, NT-proBNP levels, and arterial dysfunction in patients who had sustained acute ischemic stroke. Increased epicardial fat thickness might be a novel risk factor and might enable evaluation of subclinical target-organ damage in these patients.

Atrial fibrillation coincides with the advanced glycation end product N(ε)-(carboxymethyl)lysine in the atrium

Presence of advanced glycation end products (AGEs) in the heart induces a proinflammatory phenotype. However, the presence of AGEs within atrial tissue of atrial fibrillation (AF) patients is unknown and was analyzed here. Left atrial appendage tissue from 33 AF patients and 9 controls was analyzed for the presence of the major AGEs N(ε)-(carboxymethyl)lysine (CML), VCAM-1, neutrophilic granulocytes, lymphocytes, and macrophages in both the fat tissue and myocardium separately. The total amount of fibrosis was also analyzed. Presence of CML was significantly higher in blood vessels of the left atrial appendage in AF patients as compared to controls, independent of diabetes mellitus. In AF patients, VCAM-1 expression in blood vessels and the numbers of infiltrated neutrophilic granulocytes, lymphocytes, and macrophages significantly increased compared to controls, and were highest in the fat tissue; there was no significant difference in fibrosis compared to controls. Interestingly, total amount of CML and fibrosis in AF and control patients correlated positively. Finally, there was no difference between AF patients based on AF type or surgical indication in the presence of CML, VCAM-1 expression, inflammatory cells, and fibrosis. Our results indicate that in AF the intramyocardial blood vessels of the left atrial appendage have an increased CML presence and proinflammatory status coinciding with a local increase in the number of inflammatory cells.

Perivascular adipose tissue: An unique fat compartment relevant for the cardiometabolic syndrome

Type 2 diabetes and its major risk factor, obesity, are an increasing worldwide health problem. The exact mechanisms that link obesity with insulin resistance, type 2 diabetes, hypertension, cardiovascular complications and renal diseases, are still not clarified sufficiently. Adipose tissue in general is an active endocrine and paracrine organ that may influence the development of these disorders. Excessive body fat in general obesity may also cause quantitative and functional alterations of specific adipose tissue compartments. Beside visceral and subcutaneous fat depots which exert systemic effects by the release of adipokines, cytokines and hormones, there are also locally acting fat depots such as peri- and epicardial fat, perivascular fat, and renal sinus fat. Perivascular adipose tissue is in close contact with the adventitia of large, medium and small diameter arteries, possesses unique features differing from other fat depots and may act also independently of general obesity. An increasing number of studies are dealing with the "good" or "bad" characteristics and functions of normally sized and dramatically increased perivascular fat mass in lean or heavily obese individuals. This review describes the origin of perivascular adipose tissue, its different locations, the dual role of a physiological and unphysiological fat mass and its impact on diabetes, cardiovascular and renal diseases. Clinical studies, new imaging methods, as well as basic research in cell culture experiments in the last decade helped to elucidate the various aspects of the unique fat compartment.

Automated quantification of epicardial adipose tissue in cardiac magnetic resonance imaging

Cardiovascular disease is one of the leading causes of death worldwide. Epicardial adipose tissue (EAT) has emerged as an independent predictor of high cardiometabolic risk. Cardiovascular MRI has proven to be a feasible and reproducible method to assess EAT quantitatively. We present a novel approach for the automated quantification of EAT using "a priori" anatomical information. We extracted a region of interest (ROI) in the end-diastolic heart phase followed by a GVF-snake algorithm to smooth it. For the EAT and endocardial boundary detection, a Law's texture filter is applied. Left and right ventricle are localized using spatial prior information. Then, thresholding is applied to quantify the cardiac muscle. For the EAT, it is differentiated from the paracardial fat by K-cosine curvature analysis. Results for 10 morbidly obese patients show no significant differences between manual and automatic quantification with a remarkable time and effort saving between them.

New Insights into the Role of Metformin Effects on Serum Omentin-1 Levels in Acute Myocardial Infarction: Cross-Sectional Study

Background. Serum omentin-1 level was low in the most types of ischemic heart disease compared to normal subjects; it also dependently correlated with coronary heart disease; thus, omentin-1 is regarded as a novel biomarker in IHD. Objective. The aim of the present study was to establish the links between omentin-1 and acute myocardial infarction in metformin patients. Subjects and Methods. A cross-sectional study was performed on eighty-five patients with type II DM and acute MI. They are divided as follows: Group I, 62 patients with type II DM who received metformin prior to onset of acute MI; Group II, 23 patients with type II DM who did not receive metformin prior to onset of acute MI; and Group III, 30 normal healthy controls. Venous blood was drawn from each participant for determination of lipid profile, plasma omentin-1, cardiac troponin-I (cTn-I) and other routine tests. Results. Patients that presented with acute MI that received metformin show a significant difference in all biochemical parameters (p < 0.001); metformin increases serum omentin-1 level and decreases serum cardiac troponin-I level compared with control subjects and nonmetformin treated patients. Conclusion. Metformin pharmacotherapy increases omentin-1 serum levels and may be regarded as a potential agent in the prevention of the occurrences of acute MI in diabetic patients.

Is the Amount of Coronary Perivascular Fat Related to Atherosclerosis?

Interesting and stimulating data about the effect of the perivascular adipose tissue size on atherogenesis are based mainly on CT findings. We studied this topic by directly analyzing perivascular adipose tissue in explanted hearts from patients undergoing transplantation. Ninety-six consecutive patients were included, including 58 with atherosclerotic coronary heart disease (CHD) and 38 with dilation cardiomyopathy (DCMP). The area of perivascular fat, area of the coronary artery wall, and ratio of CD68-positive macrophages within the perivascular fat and within the vascular wall were quantified by immunohistochemistry. There was no significant difference in the perivascular adipose tissue size between the two groups. Nevertheless, there was a significantly higher number of macrophages in the coronary arterial wall of CHD patients. In addition, we found a close relationship between the ratio of macrophages in the arterial wall and adjacent perivascular adipose tissue in the CHD group, but not in the DCMP group. According to our data interaction between macrophages in the arterial wall and macrophages in surrounding adipose tissue could be more important mechanism of atherogenesis than the size of this tissue itself.

STAT4 contributes to adipose tissue inflammation and atherosclerosis

Adipose tissue (AT) inflammation is an emerging factor contributing to cardiovascular disease. STAT4 is a transcription factor expressed in adipocytes and in immune cells and contributes to AT inflammation and insulin resistance in obesity. The objective of this study was to determine the effect of STAT4 deficiency on visceral and peri-aortic AT inflammation in a model of atherosclerosis without obesity. Stat4(-/-)Apoe(-/-) mice and Apoe(-/-) controls were kept either on chow or Western diet for 12 weeks. Visceral and peri-aortic AT were collected and analyzed for immune composition by flow cytometry and for cytokine/chemokine expression by real-time PCR. Stat4(-/-)Apoe(-/-) and Apoe(-/-) mice had similar body weight, plasma glucose, and lipids. Western diet significantly increased macrophage, CD4+, CD8+, and NK cells in peri-aortic and visceral fat in Apoe(-/-) mice. In contrast, in Stat4(-/-)Apoe(-/-) mice, a Western diet failed to increase the percentage of immune cells infiltrating the AT. Also, IL12p40, TNFa, CCL5, CXCL10, and CX3CL1 were significantly reduced in the peri-aortic fat in Stat4(-/-)Apoe(-/-) mice. Importantly, Stat4(-/-)Apoe(-/-) mice on a Western diet had significantly reduced plaque burden vs Apoe(-/-) controls. In conclusion, STAT4 deletion reduces inflammation in peri-vascular and visceral AT and this may contribute via direct or indirect effects to reduced atheroma formation.