Epicardial adipose tissue: emerging physiological, pathophysiological and clinical features

Epicardial fat, cardiac geometry and cardiac function in patients with non-alcoholic fatty liver disease: association with the severity of liver disease

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) has been associated with increased cardiovascular risk, including coronary artery disease and cardiac dysfunction. In addition, recent evidence highlighted the possible role of epicardial fat as a new cardiometabolic risk factor. We tested the correlation between epicardial fat, alterations in cardiac geometry and function, and severity of liver damage, in patients with biopsy-proven NAFLD.

METHODS

The anthropometric, biochemical and metabolic features were recorded in 147 consecutive biopsy-proven NAFLD cases (Kleiner score). Epicardial fat thickness was measured by echocardiography.

RESULTS

Epicardial fat was higher in patients with severe vs. milder fibrosis (8.5 ± 3.0 vs. 7.2 ± 2.3 mm; p=0.006); this association was maintained at multivariate logistic regression analysis (OR 1.22, 95%C.I. 1.01-1.47; p=0.04) after correction for gender, age >50 years, visceral obesity, IFG/diabetes, non-alcoholic steatohepatitis and severe steatosis. Of note, 37.1% of patients with epicardial fat >7 mm (median value) had severe liver fibrosis, compared to 18.3% of the cases with lower epicardial fat (p=0.01). As for echocardiographic indices, after adjusting for cardiometabolic confounders, diastolic posterior-wall thickness (p=0.01), left ventricular mass (p=0.03), relative wall thickness (p=0.02), and left atrial volume (0.04), as well as ejection fraction (p=0.004), lower lateral TDI e' (p=0.009), E/A ratio (0.04) (cardiac geometry alterations and diastolic dysfunction) were linked to severe liver fibrosis.

CONCLUSIONS

In patients with NAFLD, a higher epicardial fat thickness is associated with the severity of liver fibrosis, in keeping with a possible pathogenic role of ectopic fat depots in whole body organ damage. In addition, morphological and functional cardiac alterations are more pronounced according to the severity of fibrosis. Further studies are needed to validate our results.

Preclinical evaluation of the immunomodulatory properties of cardiac adipose tissue progenitor cells using umbilical cord blood mesenchymal stem cells: a direct comparative study

Cell-based strategies to regenerate injured myocardial tissue have emerged over the past decade, but the optimum cell type is still under scrutiny. In this context, human adult epicardial fat surrounding the heart has been characterized as a reservoir of mesenchymal-like progenitor cells (cardiac ATDPCs) with potential clinical benefits. However, additional data on the possibility that these cells could trigger a deleterious immune response following implantation are needed. Thus, in the presented study, we took advantage of the well-established low immunogenicity of umbilical cord blood-derived mesenchymal stem cells (UCBMSCs) to comparatively assess the immunomodulatory properties of cardiac ATDPCs in an in vitro allostimulatory assay using allogeneic mature monocyte-derived dendritic cells (MDDCs). Similar to UCBMSCs, increasing amounts of seeded cardiac ATDPCs suppressed the alloproliferation of T cells in a dose-dependent manner. Secretion of proinflammatory cytokines (IL6, TNFα, and IFNγ) was also specifically modulated by the different numbers of cardiac ATDPCs cocultured. In summary, we show that cardiac ATDPCs abrogate T cell alloproliferation upon stimulation with allogeneic mature MDDCs, suggesting that they could further regulate a possible harmful immune response in vivo. Additionally, UCBMSCs can be considered as valuable tools to preclinically predict the immunogenicity of prospective regenerative cells.

The effect of hypertension and obesity on left ventricular geometry and cardiac functions in children and adolescents

OBJECTIVES

Obesity and hypertension are associated with structural and functional cardiac change in children and adults. The aim of the study is to evaluate the effect of hypertension and obesity on left ventricular geometric patterns and cardiac functions assessed by conventional and Doppler echocardiography.

METHODS

Four hundred and thirty obese children, aged 6-17 years and 150 age and sex-matched healthy controls, were included in the study. Left ventricular geometry was classified as concentric hypertrophy, eccentric hypertrophy, concentric remodeling and normal geometry.

RESULTS

Concentric hypertrophy group had the worst subclinical systolic and diastolic cardiac functions among all left ventricular geometric patterns. BMI and total adipose tissue mass are the predictors of abnormal ventricular geometry. Apart from the increase in carotid intima-media and epicardial adipose tissue thicknesses in different left ventricular geometry patterns, they are not predictable for abnormal geometry.

CONCLUSION

The variety of alterations in cardiac function and morphology that has been observed in obese adults, appears to start earlier in life. Obesity and hypertension were clearly associated with the left ventricular geometry. Also, subclinical systolic and load-depended diastolic dysfunctions can be detected in obese hypertensive children with concentric hypertrophy.

Adipogenesis and epicardial adipose tissue: a novel fate of the epicardium induced by mesenchymal transformation and PPARγ activation

The hearts of many mammalian species are surrounded by an extensive layer of fat called epicardial adipose tissue (EAT). The lineage origins and determinative mechanisms of EAT development are unclear, in part because mice and other experimentally tractable model organisms are thought to not have this tissue. In this study, we show that mouse hearts have EAT, localized to a specific region in the atrial-ventricular groove. Lineage analysis indicates that this adipose tissue originates from the epicardium, a multipotent epithelium that until now is only established to normally generate cardiac fibroblasts and coronary smooth muscle cells. We show that adoption of the adipocyte fate in vivo requires activation of the peroxisome proliferator activated receptor gamma (PPARγ) pathway, and that this fate can be ectopically induced in mouse ventricular epicardium, either in embryonic or adult stages, by expression and activation of PPARγ at times of epicardium-mesenchymal transformation. Human embryonic ventricular epicardial cells natively express PPARγ, which explains the abundant presence of fat seen in human hearts at birth and throughout life.

Epicardial adipose tissue: far more than a fat depot

Epicardial adipose tissue (EAT) refers to the fat depot that exists on the surface of the myocardium and is contained entirely beneath the pericardium, thus surrounding and in direct contact with the major coronary arteries and their branches. EAT is a biologically active organ that may play a role in the association between obesity and coronary artery disease (CAD). Given recent advances in non-invasive imaging modalities such a multidetector computed tomography (MDCT), EAT can be accurately measured and quantified. In this review, we focus on the evidence suggesting a role for EAT as a quantifiable risk marker in CAD, as well as describe the role EAT may play in the development and vulnerability of coronary artery plaque.

An association study between epicardial fat thickness and cognitive impairment in the elderly

The amount of fat surrounding the heart, called epicardial adipose tissue (EAT), is a marker of cardiometabolic risk and correlates with the quantity of visceral adipose tissue (VAT). The amount of VAT is associated with an increased risk of cardiovascular and cerebrovascular disease and with cognitive impairment. We aimed to evaluate the association between EAT thickness as a measure of VAT and cognitive function. In 71 elderly subjects (mean age 72.7 ± 7.1 yr) we measured EAT thickness through transthoracic echocardiography, assessed the metabolic profile through evaluation of biochemical parameters, and estimated the cognitive function via the Mini Mental State Examination (MMSE). We found that greater EAT thickness was associated with lower cognitive performance evaluated by MMSE (P < 0.01) independently of the presence or absence of metabolic syndrome or obesity. Lower MMSE results were also associated with the presence of metabolic syndrome (P < 0.01), elevated HOMA index (P < 0.01), and high BMI values (P < 0.01). The results of mediation analysis confirmed that the total effect of metabolic syndrome, HOMA, and BMI on MMSE is mainly explained by an indirect effect through EAT thickness. In conclusion, increased EAT thickness assessed by transthoracic echocardiography is associated with deficient results of psychometric tests assessing cognitive performance and may consistently foresee impairment of cognition in the elderly.

Cardiac adipose tissue and its relationship to diabetes mellitus and cardiovascular disease

Type-2 diabetes mellitus (T2DM) plays a central role in the development of cardiovascular disease (CVD). However, its relationship to epicardial adipose tissue (EAT) and pericardial adipose tissue (PAT) in particular is important in the pathophysiology of coronary artery disease. Owing to its close proximity to the heart and coronary vasculature, EAT exerts a direct metabolic impact by secreting proinflammatory adipokines and free fatty acids, which promote CVD locally. In this review, we have discussed the relationship between T2DM and cardiac fat deposits, particularly EAT and PAT, which together exert a big impact on the cardiovascular health.

Epicardial fat thickness as cardiovascular risk factor and therapeutic target in patients with rheumatoid arthritis treated with biological and nonbiological therapies

Rheumatoid arthritis (RA) is a chronic inflammatory disease associated with high cardiovascular morbidity and mortality. Epicardial adipose tissue (EAT) thickness may act as a therapeutic target during treatments with drugs modulating the adipose tissue. We evaluate EAT thickness in RA patients treated with biological and nonbiological disease-modifying antirheumatic drugs (DMARDs). A cross-sectional study was conducted with a cohort of 34 female RA patients and 16 controls matched for age and body mass index (BMI). Plasma glucose, basal insulin, plasma lipids, and high-sensitivity C-reactive protein (hs-CRP) were assessed. EAT thickness and left ventricular mass (LVM) were measured by echocardiography. No significant differences in waist circumference (WC), blood pressure, fasting blood glucose, basal insulin, and lipid parameters were found between the groups. The control group showed lower concentrations (P = 0.033) of hs-CRP and LVM (P = 0.0001) than those of the two RA groups. Patients treated with TNF-α inhibitors showed significantly lower EAT thickness than those treated with nonbiological DMARDs (8.56 ± 1.90 mm versus 9.71 ± 1.45 mm; P = 0.04). Women with no RA revealed reduced EAT thickness (5.39 ± 1.52 mm) as compared to all RA patients (P = 0.001). Results suggest that RA patients have greater EAT thickness than controls regardless of BMI and WC.

Nonalcoholic fatty liver disease and vascular disease: State-of-the-art

Nonalcoholic fatty liver disease (NAFLD), the most common of chronic liver disease in Western Country, is closely related to insulin resistance and oxidative stress and includes a wide spectrum of liver diseases ranging from steatosis alone, usually a benign and non-progressive condition, to nonalcoholic steatohepatitis (NASH), which may progress to liver fibrosis and cirrhosis. NAFLD is considered the hepatic manifestation of the metabolic syndrome with which shares several characteristics, however recent data suggest that NAFLD is linked to increased cardiovascular risk independently of the broad spectrum of risk factors of metabolic syndrome. Accumulating evidence suggests that the clinical burden of NAFLD is not restricted to liver-related morbidity and mortality, with the majority of deaths in NAFLD patients related to cardiovascular disease and cancer and not to the progression of liver disease. Retrospective and prospective studies provide evidence of a strong association between NAFLD and subclinical manifestation of atherosclerosis (increased intima-media thickness, endothelial dysfunction, arterial stiffness, impaired left ventricular function and coronary calcification). A general agreement emerging from these studies indicates that patients with NASH are at higher risk of cardiovascular diseases than those with simple steatosis, emphasizing the role of chronic inflammation in the pathogenesis of atherosclerosis of these patients. It is very likely that the different mechanisms involved in the pathogenesis of atherosclerosis in patients with NAFLD have a different relevance in the patients according to individual genetic background. In conclusion, in the presence of NAFLD patients should undergo a complete cardiovascular evaluation to prevent future atherosclerotic complications. Specific life-style modification and aggressive pharmaceutical modification will not only reduce the progression of liver disease, but also reduce morbidity for cardiovascular disease improving overall prognosis and survival.

Arrhythmogenic evidence for epicardial adipose tissue: heart rate variability and turbulence are influenced by epicardial fat thickness

BACKGROUND

Epicardial adipose tissue (EAT) is a local source of various hormones, cytokines, and vasoactive substances affecting the myocardium. EAT contains abundant ganglionic plexi that interact with the autonomic nervous system. Evidence of the association between EAT and arrhythmia is limited, with the exception of atrial fibrillation. This study aimed to investigate the relation between EAT and cardiac autonomic function using heart rate variability (HRV) and heart rate turbulence (HRT) parameters.

METHODS

All subjects underwent a 24-hour Holter recording to assess HRV and HRT parameters and a transthoracic echocardiography to measure EAT thickness. Patients were divided into two groups according to the median EAT thickness (3.9 mm). The higher EAT group consisted of 111 patients with a >3.9-mm thickness and the lower EAT group 113 patients with a ≤ 3.9-mm EAT thickness.

RESULTS

HRV and HRT parameters were significantly influenced in the higher EAT group. Moreover, we observed significant correlations between EAT thickness and Holter findings (standard deviation of all NN intervals [SDNN]: r = -0.462, P < 0.001; SDNN index: r = -0.349, P < 0.001; standard deviation of the average NN intervals: r = -0.465, P < 0.001; root mean square of successive differences: r = -0.251, P < 0.001; pNN50: r = -0.354, P < 0.001; turbulence onset: r = 0.172, P = 0.010; turbulence slope: r = -0.279, P < 0.001, HRT category: r = 0.169, P = 0.011). In multivariate regression analysis, EAT thickness was independently associated with all measures of HRV and HRT, with the exception of turbulence onset.

CONCLUSIONS

Sympathovagal imbalance, detected by HRV and HRT parameters, is related to EAT thickness. As sympathovagal imbalance is a predictor of arrhythmic events, EAT may play an important arrhythmogenic role not limited to atrial fibrillation.

Epicardial fat, rather than pericardial fat, is independently associated with diastolic filling in subjects without apparent heart disease

BACKGROUND AND AIM

Epicardial and pericardial fat are separate fat depots surrounding the heart. Previous studies found epicardial fat to be associated with diastolic dysfunction, but they had some limitations. Pericardial fat association with diastolic dysfunction was not examined. Our aim was to assess the relation of epicardial and pericardial fat with diastolic filling.

METHODS AND RESULTS

In 73 volunteers without known heart disease or complaints, using echocardiography, we measured epicardial and pericardial fat thickness from long(LAX) and short(SAX) axis views and assessed diastolic filling: mitral inflow (E/A ratio, E wave deceleration time[DT]), pulmonary vein flow (systolic/diastolic ratio [S/D], systolic filling fraction[SFR], late retrograde velocity[Ar]), color M-mode flow propagation velocity [Vp], and tissue Doppler derived mitral early annular velocities at the septum [e' sep] and lateral wall [e'-lat]. By Spearman's correlation, epicardial fat from LAX had a weak, but statistically significant correlations with several diastolic filling indices (SFR{rs = 0.29, P = 0.02}, Ar{rs = 0.3, P = 0.01}, Vp{rs = -0.3, P = 0.01}, e' sep{rs = -0.23, P = 0.04}, e' lat{rs = -0.26, P = 0.03}). In multivariate logistic regression model adjusting for age, gender, diabetes, systolic blood pressure and left ventricle mass index, epicardial fat thickness from LAX (and not from SAX) was the only independent predictor of e' [e' sep < 8: OR = 1.8, 95%CI = 1.1-2.9; e' lat<10: OR = 1.6, 95%CI = 1.01-2.6]. After adjustment, Pericardial fat measured from LAX was independent predictor of e' lat only[e' lat < 10:OR = 1.3, 95% CI 1.03-1.6).

CONCLUSIONS

Epicardial fat measured from LAX is an independent predictor of myocardial relaxation. Pericardial fat independent association with diastolic filling is uncertain.

Increased epicardial fat and plasma leptin in type 1 diabetes independently of obesity

BACKGROUND AND AIM

Visceral fat and related adipokines, such as leptin and adiponectin, have been recently suggested to play a role in type 1 diabetes. Nevertheless epicardial fat, the visceral fat of the heart, has been poorly explored in type 1 diabetes. In this study we sought to measure epicardial fat thickness, plasma leptin and adiponectin levels in type 1 diabetic subjects.

METHODS AND RESULTS

15 subjects with type 1 diabetes (age 52.8 ± 12, 10 females, 5 males, BMI 27.8 ± 5.2) and 15 non-diabetic controls underwent echocardiographic epicardial fat thickness measurement and blood tests for adipokines and Hemoglobin A1c (HbA1c). There were no differences in BMI, age, sex, blood pressure, inflammatory markers and adiponectin between subjects with diabetes and controls. Daily insulin requirement of subjects with type 1 diabetes was 0.54 ± 0.2 UI/kg and HbA1c was 7.6 ± 1.0 reflecting acceptable glycemic control. Patients with Type 1 diabetes showed significantly higher epicardial fat thickness (7.2 ± 2.1 vs 4.9 ± 2.5 mm p < 0.01) and plasma leptin levels (25.9 ± 19 vs 18 ± 12 ng/ml p < 0.01) than controls. Leptin resulted in the best independent correlate of epicardial fat thickness (R(2) = 0.48, p = 0.04, β = 2.45).

CONCLUSIONS

Our study provides two major findings of novelty: 1) subjects with type 1 diabetes have higher epicardial fat and serum leptin levels than non-diabetic subjects, 2) epicardial fat thickness and serum leptin levels are the best independent correlates of each other in patients with type 1 diabetes independently of BMI, HbA1c, daily insulin requirement. The mechanisms that link epicardial fat to leptin levels in type 1 diabetes remain to be elucidated.

A low serum free triiodothyronine level is associated with epicardial adipose tissue in peritoneal dialysis patients

AIM

Cardiovascular disease is a major cause of mortality in dialysis patients. Epicardial adipose tissue (EAT) has been proposed as a cardiovascular risk marker in this population. Subclinical hypothyroidism and low free triiodothyronine (fT3) levels are associated with EAT in patients without chronic renal failure. The aim of this study was to investigate the relationship between EAT and low free T3 levels in peritoneal dialysis (PD) patients.

METHODS

A total of 125 prevalent PD patients were enrolled in this cross-sectional study. The epicardial fat thickness (EFT) was measured by echocardiography, and the endothelial function was assessed by flow mediated dilatation (FMD). Thyroid function tests were performed by an enzyme immunoassay.

RESULTS

The mean age of the patients was 51 ± 13, and the time on PD was 36 months. The mean EFT was 6.7 ± 2.9 mm. The EFT correlated positively with the patient age, systolic blood pressure (BP), mean BP, high sensitivity C-reactive protein (hs-CRP) level and body mass index (BMI), and negatively with the fT3 level and FMD. The median fT3 value was 2.53, and patients were divided according to their serum fT3 values (within the normal range and below the reference level). Compared with patients in the low fT3 group, the subjects in the normal fT3 group had higher serum albumin levels and FMD, but a lower BMI, plasma fasting glucose level, EFT, TSH level, hs-CRP level, low density lipoprotein (LDL) cholesterol level and mean BP in office measurements, and both the diastolic BP and mean BP by ambulatory blood pressure measurement. A multivariate linear regression analysis showed that the EFT was predicted by the hs-CRP and fT3 levels.

CONCLUSION

Low free T3 levels are associated with the epicardial fat thickness in PD patients. Further studies are needed to evaluate the pathogenesis and to support these findings.

Epicardial adipose tissue in endocrine and metabolic diseases

Epicardial adipose tissue has recently emerged as new risk factor and active player in metabolic and cardiovascular diseases. Albeit its physiological and pathological roles are not completely understood, a body of evidence indicates that epicardial adipose tissue is a fat depot with peculiar and unique features. Epicardial fat is able to synthesize, produce, and secrete bioactive molecules which are then transported into the adjacent myocardium through vasocrine and/or paracrine pathways. Based on these evidences, epicardial adipose tissue can be considered an endocrine organ. Epicardial fat is also thought to provide direct heating to the myocardium and protect the heart during unfavorable hemodynamic conditions, such as ischemia or hypoxia. Epicardial fat has been suggested to play an independent role in the development and progression of obesity- and diabetes-related cardiac abnormalities. Clinically, the thickness of epicardial fat can be easily and accurately measured. Epicardial fat thickness can serve as marker of visceral adiposity and visceral fat changes during weight loss interventions and treatments with drugs targeting the fat. The potential of modulating the epicardial fat with targeted pharmacological agents can open new avenues in the pharmacotherapy of endocrine and metabolic diseases. This review article will provide Endocrine's reader with a focus on epicardial adipose tissue in endocrinology. Novel, established, but also speculative findings on epicardial fat will be discussed from the unexplored perspective of both clinical and basic Endocrinologist.

Chemerin and CMKLR1 expression in human arteries and periadventitial fat: a possible role for local chemerin in atherosclerosis?

BACKGROUND

Depending on their anatomical location, different fat depots have a different capacity to produce bioactive peptides, called adipokines. Adipokines produced by periadventitial fat have been implicated in the pathogenesis of vascular disease, including atherosclerosis. Chemerin is an adipokine with an established role in immunity, adipose tissue function and metabolism, acting in autocrine, paracrine and endocrine manners. We investigated the protein expression of chemerin and its receptor, CMKLR1, in human aortas, coronary vessels and the respective periadventitial adipose tissue and correlated their expression with the presence of atherosclerosis.

METHODS

Immunohistochemistry for chemerin and CMKLR1 was performed on human aortic and coronary artery samples including the periadventitial adipose tissue. Aortic and coronary atherosclerotic lesions were assessed using the AHA classification.

RESULTS

Chemerin immunopositivity was noticed in both periadventitial fat depots, in vascular smooth muscle cells and foam cells in atherosclerotic lesions. Periadventitial fat and foam cell chemerin immunopositivity was statistically significantly correlated with the severity of atherosclerosis in both locations. CMKLR1 was expressed in vascular smooth muscle cells and foam cells in aortic and coronary vessels with atherosclerotic lesions. CMKLR1 immunostaining in foam cells was statistically significantly correlated with aortic atherosclerosis.

CONCLUSIONS

Our results lend some support to a presumable role of locally produced chemerin in the progression of atherosclerotic lesions, possibly acting through its CMKLR1 receptor. Further research will elucidate the role of chemerin signaling in atherosclerosis.

Does epicardial adipose tissue volume provide information about the presence and localization of coronary artery disease?

Objective

This study is important for the determination of branches and segments of the first atherosclerotic coronary artery. The objective was to examine the role of epicardial adipose tissue (EAT) volume in estimating the presence and localization of plaque of coronary arteries.

Methods

Our study is a retrospective study, consisting of 50 male (mean age: 45.5±12 yrs) and 58 female (mean age: 52.5±11.6 yrs). A total of 108 consecutive patients underwent coronary computerized tomography (CT) angiography. Each coronary artery segment was assessed for the presence of atherosclerotic plaque. According to the plaque-involved vessel, patients were grouped as without plaque; plaque-involved left anterior descending artery (LAD), right coronary artery (RCA), or circumflex artery (Cx); and mixed (two or more vessels).

Results

The differences in mean values between the two groups were compared using the independent samples t test. Mann-Whitney U test was used for the comparison of continuous variables among groups. While EAT volume was found to be higher in the group with plaque, the difference between the two groups was statistically significant (88.6±9.2 cm³, 67.4±7.2 cm³, respectively, p=0.001). EAT volume was 67.3±7.1 cm³ in the without plaque group, 97.7±22.8 cm³ in LAD, 79.7±10.1 cm³ in RCA, 70.7±8.9 cm³ in Cx, and 101.9±18.6 cm³ in mixed vessels. In the intragroup comparison, the EAT volume of plaque-involved LAD and mixed vessels was significantly higher than in the other groups. The EAT volume of plaque-involved RCA was significantly higher (p=0.015) than in plaque-involved Cx.

Conclusion

Increased EAT volume is directly proportional to the presence of coronary artery plaques, especially in LAD and with more than one artery.

Effect of hypertension on echocardiographic parameters in rheumatoid arthritis

OBJECTIVE

Hypertension (HTN) is common in rheumatoid arthritis (RA) patients. Both HTN and RA have a negative impact on echocardiographically determined parameters including wall thickness, chamber diameter, diastolic function, epicardial adipose tissue (EAT) and carotid intima media thickness (CIMT). We aimed to demonstrate the effect of HTN on these parameters in RA patients.

METHODS

Patients were divided into two groups: one group comprised 39 RA patients with HTN (7 male, mean age 56.3 ± 8.4 years) and the second comprised 38 age- and gender-matched RA patients without HTN (10 male, mean age 55.3 ± 7.4 years). We retrospectively analyzed the RA patients without overt structural heart disease by determining the study parameters from echocardiograph recordings. The two groups were compared in terms of echocardiographic parameters and disease characteristics.

RESULTS

RA characteristics, chamber sizes and wall thicknesses did not differ between the groups. CIMT was significantly increased in the RA with HTN group (median 0.9 mm, range 0.6-1.2 mm vs. median 0.8 mm, range 0.6-1.0 mm; p = 0.031). EAT was also significantly increased in the RA with HTN group (8.2 ± 1.8 mm vs. 7.4 ± 1.4 mm; p = 0.022). Septal early diastolic E' wave velocities were significantly decreased in the RA with HTN group (8.8 ± 2.4 cm/s vs. 10.2 ± 1.8 cm/s; p = 0.016).

CONCLUSION

HTN has a further negative impact on diastolic functions, CIMT and EAT in RA patients.

Epicardial adipose tissue and atrial fibrillation

Atrial fibrillation (AF) is the most frequent cardiac arrhythmia in clinical practice. AF is often associated with profound functional and structural alterations of the atrial myocardium that compose its substrate. Recently, a relationship between the thickness of epicardial adipose tissue (EAT) and the incidence and severity of AF has been reported. Adipose tissue is a biologically active organ regulating the metabolism of neighbouring organs. It is also a major source of cytokines. In the heart, EAT is contiguous with the myocardium without fascia boundaries resulting in paracrine effects through the release of adipokines. Indeed, Activin A, which is produced in abundance by EAT during heart failure or diabetes, shows a marked fibrotic effect on the atrial myocardium. The infiltration of adipocytes into the atrial myocardium could also disorganize the depolarization wave front favouring micro re-entry circuits and local conduction block. Finally, EAT contains progenitor cells in abundance and therefore could be a source of myofibroblasts producing extracellular matrix. The study on the role played by adipose tissue in the pathogenesis of AF is just starting and is highly likely to uncover new biomarkers and therapeutic targets for AF.

Validation of anthropometric indices of adiposity against whole-body magnetic resonance imaging--a study within the German European Prospective Investigation into Cancer and Nutrition (EPIC) cohorts

Background

In epidemiological studies, measures of body fat generally are obtained through anthropometric indices such as the body mass index (BMI), waist (WC), and hip circumferences (HC). Such indices, however, can only provide estimates of a person’s true body fat content, overall or by adipose compartment, and may have limited accuracy, especially for the visceral adipose compartment (VAT).

Objective

To determine the extent to which different body adipose tissue compartments are adequately predicted by anthropometry, and to identify anthropometric measures alone, or in combination to predict overall adiposity and specific adipose tissue compartments, independently of age and body size (height).

Methods

In a sub-study of 1,192 participants of the German EPIC (European Prospective Investigation into Cancer and Nutrition) cohorts, whole-body MRI was performed to determine adipose and muscle tissue compartments. Additional anthropometric measurements of BMI, WC and HC were taken.

Results

After adjusting for age and height, BMI, WC and HC were better predictors of total body volume (TBV), total adipose tissue (TAT) and subcutaneous adipose tissue (SAT) than for VAT, coronary adipose tissue (CAT) and skeletal muscle tissue (SMT). In both sexes, BMI was the best predictor for TBV (men: r = 0.72 [0.68–0.76], women: r = 0.80 [0.77–0.83]) and SMT (men: r = 0.52 [0.45–0.57], women: r = 0.48 [0.41–0.54]). WC was the best predictor variable for TAT (r = 0.48 [0.41–0.54]), VAT (r = 0.44 [0.37–0.50]) and CAT (r = 0.34 [0.26–0.41]) (men), and for VAT (r = 0.42 [0.35–0.49]) and CAT (r = 0.29 [0.22–0.37]) (women). BMI was the best predictor for TAT (r = 0.49 [0.43–0.55]) (women). HC was the best predictor for SAT (men (r = 0.39 [0.32–0.45]) and women (r = 0.52 [0.46–0.58])).

Conclusions

Especially the volumes of internal body fat compartments are poorly predicted by anthropometry. A possible implication may be that associations of chronic disease risks with the sizes of internal body fat as measured by BMI, WC and HC may be strongly underestimated.

Differential behavior between S100A9 and adiponectin in coronary artery disease. Plasma or epicardial fat

AIMS

S100A9 is a new inflammatory marker associated with obesity and cardiovascular disease. Because epicardial adipose tissue (EAT) is an inflammatory source in coronary artery disease (CAD), our aim was to evaluate the S100A9 levels in plasma and EAT and its association with CAD.

MAIN METHODS

Blood, EAT and/or subcutaneous adipose tissue (SAT) biopsies were obtained from 89 patients undergoing elective cardiac surgery. Plasma S100A9 and adiponectin were analyzed by enzyme-linked immunosorbent assay (ELISA) and mRNA expression in both fat pads and were measured by real-time polymerase chain reaction (PCR).

KEY FINDINGS

Our results have shown higher levels of plasma S100A9 in patients with CAD than those without (29 [10-50] vs. 17 [3-28] ng/mL; p=0.007). They were dependent on the number of injured-coronaries (p=0.002) with tendency toward negative association with plasma adiponectin (p=0.139). Although EAT expressed higher levels than SAT and their levels were higher in CAD patients, this last difference did not reach statistical significance. However, there was a positive correlation between neutrophils and EAT S100A9 expression (p=0.007) that may reveal an increase of neutrophil filtration on this fat pad.

SIGNIFICANCE

Plasma S100A9 levels are increased in chronic CAD. The absence of differences regarding EAT S100A9 expression levels indicates a differential inflammatory process between fat tissues and blood in CAD process.

Epicardial fat thickness and nonalcoholic fatty liver disease in obese subjects

OBJECTIVE

Ectopic fat accumulation within the heart and the liver are linked to an increased cardiovascular risk. Ultrasound-measured cardiac and liver steatosis are easily accessible markers of intra-organ ectopic fat accumulation. The hypothesis that echocardiographic epicardial fat thickness is independently associated with nonalcoholic fatty liver disease (NAFLD) in obese subjects is tested.

DESIGN AND METHODS

Sixty-two obese (BMI > 30 kg m⁻²) subjects with ultrasonographic evidence of NAFLD and 62 control obese subjects without history or signs of NAFLD underwent echocardiographic epicardial fat thickness measurement.

RESULTS

Epicardial fat thickness was significantly higher (P < 0.01) in obese subjects with NAFLD when compared to those without NAFLD. Epicardial fat thickness was significantly higher (9.7 ± 0.2 vs. 8 ± 0.7 mm, P < 0.01) in subjects with severe (ultrasound score 3) than those with moderate (score 2) liver steatosis. Among waist circumference and BMI, epicardial fat thickness resulted in the best independent correlate of liver steatosis (R²  = 0.77, P < 0.001).

CONCLUSIONS

Our study suggests that epicardial fat is a good predictor of liver steatosis in obese subjects. Echocardiographic epicardial fat predicts ultrasound-measured fatty liver better than BMI or waist circumferences does. Patients with severe fatty liver infiltration presented with the highest amount of cardiac fat accumulation.

Cardiometabolic risk factors in patients with erectile dysfunction

Introduction. There is an increasing interest in the association between erectile dysfunction (ED) and cardiovascular risk factor. Epicardial adipose tissue (EAT) is associated with insulin resistance, increased cardiometabolic risk, and coronary artery disease. Our aim was to investigate relationships between epicardial fat thickness (EFT) as a cardiometabolic risk factor and erectile dysfunction. Method. We selected 30 erectile dysfunction patients without comorbidities and 30 healthy individuals. IIEF-5 score was applied to all patients, and IIEF-5 score below 22 was considered as erectile dysfunction. EFT was measured by echocardiography. Results. Body mass index (BMI) was higher in ED patients than those without ED (28.19 ± 4.45 kg/m² versus 23.84 ± 2.36 kg/m², P = 0.001, resp.). Waist circumstance (WC) was higher in ED patients than those without ED (106.60 ± 5.90 versus 87.86 ± 14.51, P = 0.001, resp.). EFT was higher in ED patients compared to non-ED patients (0.49 ± 0.09 cm versus 0.45 ± 0.03 cm, P = 0.016, resp.). There was positive correlation among BMI, WC, and EFT. There was negative correlation between EFT and IIEF-5 score (r : − 0.632, P = 0.001). Conclusion. EAT, BMI, and WC as cardiometabolic risk factors were higher in erectile dysfunction patients.

Ectopic fat deposition and global cardiometabolic risk: new paradigm in cardiovascular medicine

The obesity epidemic is a global public health concern that increases the likelihood of morbidity and mortality of metabolic and cardiovascular disease (CVD) and threatens to reduce life expectancy around the world. The concept of the metabolic syndrome (MetS) takes into account that visceral fat plays an essential role in the development of metabolic and cardiovascular diseases. However, MetS cannot be used to assess global CVD risk but is at best one more modifiable CVD risk factor. Thus, global cardiometabolic risk (the global risk of cardiovascular disease resulting from traditional risk factors combined with the additional contribution of the metabolic syndrome and/or insulin resistance) should be considered individually. There is solid evidence supporting the notion that excess abdominal fat is predictive of insulin resistance and the presence of related metabolic abnormalities currently referred to as MetS. Despite the fact that abdominal obesity is a highly prevalent feature of MetS, the mechanisms by which abdominal obesity is causally related to MetS are not fully elucidated. Besides visceral fat accumulation, ectopic lipid deposition, especially in liver and skeletal muscle, has been implicated in the pathophysiology of diabetes, insulin resistance and obesity-related disorders. Also, ectopic fat deposition could be deteriorated in the heart components such as (1) circulatory and locally recruited fat, (2) intra- and extra-myocellular fat, (3) perivascular fat, and (4) pericardial fat. In this review, the contribution of ectopic lipid deposition to global cardiometabolic risk is reviewed and also discussed are potential underlying mechanisms including adipocytokine, insulin resistance and lipotoxicity.

Epicardial adipose tissue thickness is increased in patients with cardiac syndrome X

BACKGROUND

Cardiac syndrome X (CSX) is defined as normal coronary arteries with angina pectoris and a positive stress test. Epicardial adipose tissue (EAT) plays an important role in inflammatory process in cardiovascular system, therefore EAT may affect the pathogenesis of different cardiovascular disease. The aim of this study was to investigate the EAT thickness in patients with CSX and compare normal subjects.

METHODS

We prospectively enrolled 30 consecutive patients with CSX. The control group consisted of 30 age and sex-matched individuals with anginal chest pain and a negative treadmill or myocardial perfusion scan test. EAT thickness was measured by transthoracic echocardiography.

RESULTS

There were no differences in baseline clinical, biochemical and echocardiographic characteristics between CSX patients and the control group. Patients with CSX had significantly increased EAT thickness than those of the controls (3.43 ± 0.88 vs. 2.34 ± 0.89 mm, p=0.0001).

CONCLUSION

We found that EAT thickness is increased in patients with CSX. This finding suggests that EAT may contribute to the etiopathogenesis of the CSX.

Association of epicardial fat with left ventricular diastolic function in subjects with metabolic syndrome: assessment using 2-dimensional echocardiography

Background

Metabolic syndrome (MetS) is related with left ventricular diastolic dysfunction (LVDD) and poor cardiovascular outcome. Epicardial adipose tissue (EAT) thickness, measured by echocardiography, is increased in subjects with MetS. However, the association of EAT with LV diastolic function has not been evaluated in subjects with MetS.

Methods

In this retrospective study, EAT thickness was measured in 1,486 consecutive asymptomatic patients with no known heart disease who had transthoracic echocardiography during a self-referred healthcare exam. Subjects with a history of ischemic heart disease, cardiomyopathy or significant valvular heart disease were excluded. LVDD was defined as E/e’ ratio ≥ 15. Subjects were grouped into two groups, those with MetS and those without.

Results

MetS was present in 346 subjects. There was no difference in LV systolic function between the two groups. However compared to patients without MetS, patients with MetS had larger left atrium (LA) size and higher E/e’ ratio (38 ± 5 versus 35 ± 5 mm for LA and 10.0 ± 3.3 versus 8.7 ± 2.7 for E/e’ ratio in subjects with versus without MetS both p < 0.001). LVDD was found in 27 (7.8%) subjects with MetS, compared to 30 (2.6%) subjects without MetS (p < 0.001). In subjects with MetS, EAT was significantly correlated with LVDD, even after adjusting for other cardiometabolic risk factors such as age, systolic blood pressure, BMI, blood glucose and LDL cholesterol (OR 1.845, 95% CI 1.153-2.951, p = 0.011).

Conclusion

Greater EAT is found in subjects with MetS. EAT is significantly associated with LVDD in subjects with MetS, even after adjusting for other risk factors.

Adiponectin and p53 mRNA in epicardial and subcutaneous fat from heart failure patients

OBJECTIVE

Heart failure (HF) is associated with a pro-inflammatory state in epicardial fat, but the involved mechanisms are not entirely clear. The aim of our study was to assess the relationship between p53 and adiponectin mRNA in epicardial adipose tissue (EAT) and subcutaneous adipose tissue (SAT) in patients with heart failure and its sympathetic regulation.

METHODS

Epicardial adipose tissue and SAT samples were obtained from 63 patients undergoing elective cardiac surgery. EAT and SAT explants culture from seven patients were stimulated with isoprenaline 0.1 or 1 uM for 6 h. p53 and adiponectin mRNA expression was measured in frozen biopsies or explants culture from both fat pads by real-time polymerase chain reaction (PCR).

RESULTS

We observed that EAT expressed more p53 mRNA than SAT (1.73 ± 0.07 vs. 1.69 ± 0.04, P < 0.001) and its levels were higher in HF patients (1.75 ± 0.07 vs. 1.70 ± 0.04, P < 0.01 in EAT and 1.70 ± 0.04 vs. 1.67 ± 0.04, P < 0.05 in SAT). Moreover, p53 mRNA expression was negatively correlated with adiponectin in EAT. After analysing the p53 mRNA regulation by isoprenaline, we observed that only EAT p53 expression increased after adrenergic stimulation (1.63 ± 0.01 vs. 1.66 ± 0.02; P = 0.024).

CONCLUSIONS

p53 mRNA expression levels, inversely correlated with adiponectin, increase in EAT of HF patients and can be regulated by sympathetic activation pathway. Our findings can help to explain the deleterious effect of sympathetic activation in HF.

Relationship between epicardial adipose tissue and subclinical coronary artery disease in patients with extra-cardiac arterial disease

OBJECTIVE

Epicardial adipose tissue (EAT) and mediastinal adipose tissue (MAT) are linked to coronary artery disease (CAD). The association between EAT, MAT, and severity of CAD in known extra-cardiac arterial disease was investigated.

DESIGN AND METHODS

Sixty-five cardiac asymptomatic patients (mean age 65 ± 8 years, 69% male) with peripheral arterial disease, carotid stenosis, or aortic aneurysm underwent coronary computed tomography angiography. Patients were divided into non-significant (<50% stenosis, N = 35), single vessel (N = 15) and multi-vessel CAD (N = 15). EAT and MAT were quantified on computed tomography images using volumetric software.

RESULTS

Subgroups did not significantly differ by age, gender, or cardiovascular risk factors. Median EAT was 99.5, 98.0, and 112.0 cm(3) (P = 0.38) and median MAT was 66.0, 90.0, and 81.0 cm(3) (P = 0.53) for non-significant, single vessel, and multi-vessel CAD, respectively. In age- and gender-adjusted analysis, only EAT was significantly associated with CAD (odds ratio [OR] 1.12 [95% confidence interval, 1.01-1.25] per 10 cm(3) increase in EAT; P = 0.04). This remained in multivariate-adjusted analysis (OR 1.21 [1.04-1.39]; P = 0.01).

CONCLUSIONS

In patients with known extra-cardiac arterial disease, CAD is correlated with EAT, but not with MAT. These results suggest that EAT has a local effect on coronary atherosclerosis, apart from the endocrine effect of visceral fat.

Increased epicardial adipose tissue thickness is linked to aortic stiffness in patients with primary hypertension

AIMS

In patients with hypertension (HT), increased aortic stiffness is related to higher cardiovascular morbidity and mortality. Recent investigations have shown that epicardial adipose tissue (EAT) is a new potential cardiometabolic risk factor. The aim of our study was to examine the relation between echocardiographically measured EAT thickness and aortic stiffness in patients with primary HT.

METHODS

The study included 144 newly diagnosed and untreated essential hypertensive outpatients. Transthoracic echocardiographic EAT thickness and aortic stiffness measurements were performed for all study participants. Afterwards patients were divided in two groups according to their median EAT thickness values. The patients with EAT thickness of < 7 mm were included in group 1 and patients with EAT thickness of ≥ 7 mm were included in group 2.

RESULTS

Aortic strain and distensibility parameters of group 2 were lower than in group 1. The aortic stiffness index of group 2 was found to be higher than group 1. Multivariate regression analysis revealed that EAT thickness was the only independent variable for all three parameters of aortic stiffness index, aortic strain and aortic distensibility.

CONCLUSION

In patients with newly diagnosed primary HT, increased EAT thickness was significantly linked to impaired aortic elastic properties independently of other conventional adiposity measurements.

Automated quantification of epicardial adipose tissue using CT angiography: evaluation of a prototype software

OBJECTIVES

This study evaluated the performance of a novel automated software tool for epicardial fat volume (EFV) quantification compared to a standard manual technique at coronary CT angiography (cCTA).

METHODS

cCTA data sets of 70 patients (58.6 ± 12.9 years, 33 men) were retrospectively analysed using two different post-processing software applications. Observer 1 performed a manual single-plane pericardial border definition and EFVM segmentation (manual approach). Two observers used a software program with fully automated 3D pericardial border definition and EFVA calculation (automated approach). EFV and time required for measuring EFV (including software processing time and manual optimization time) for each method were recorded. Intraobserver and interobserver reliability was assessed on the prototype software measurements. T test, Spearman's rho, and Bland-Altman plots were used for statistical analysis.

RESULTS

The final EFVA (with manual border optimization) was strongly correlated with the manual axial segmentation measurement (60.9 ± 33.2 mL vs. 65.8 ± 37.0 mL, rho = 0.970, P < 0.001). A mean of 3.9 ± 1.9 manual border edits were performed to optimize the automated process. The software prototype required significantly less time to perform the measurements (135.6 ± 24.6 s vs. 314.3 ± 76.3 s, P < 0.001) and showed high reliability (ICC > 0.9).

CONCLUSIONS

Automated EFVA quantification is an accurate and time-saving method for quantification of EFV compared to established manual axial segmentation methods.

KEY POINTS

• Manual epicardial fat volume quantification correlates with risk factors but is time-consuming. • The novel software prototype automates measurement of epicardial fat volume with good accuracy. • This novel approach is less time-consuming and could be incorporated into clinical workflow.

Intima-media thickness in severe obesity: links with BMI and metabolic status but not with systemic or adipose tissue inflammation

OBJECTIVE

Obesity is associated with cardiovascular risk and a low-grade inflammatory state in both blood and adipose tissue (AT). Whether inflammation contributes to vascular alteration remains an open question. To test this hypothesis, we measured arterial intima-media thickness (IMT), which reflects subclinical atherosclerosis, in severely obese subjects and explored associations with systemic inflammation and AT inflammation.

RESEARCH DESIGN AND METHODS

IMT of the carotid artery (C-IMT) and IMT of the femoral artery (F-IMT) were measured in 132 nonobese (control) subjects (BMI 22.3 kg/m2; mean age 44.8 years) and 232 subjects who were severely obese without diabetes (OB/ND; n = 146; BMI 48.3 kg/m2; age 38.2 years) or severely obese with type 2 diabetes (OB/D; n = 86; BMI 47.0; age 49.4 years). In 57 OB/ND subjects, circulating soluble E-selectin, matrix metalloproteinase 9, myeloperoxidase, soluble intracellular adhesion molecule 1, soluble vascular cell adhesion molecule 1, tissue plasminogen activator inhibitor 1, cystatin C, cathepsin S, and soluble CD14 were measured in serum. AT macrophages were quantified by CD68 immunochemistry.

RESULTS

Both C-IMT and F-IMT increased in OB/ND and OB/D patients. In OB/ND patients, age was the sole independent determinant of IMT. No significant association was found with circulating inflammation-related molecules, number of CD68+ cells, or the presence of crown-like structures in visceral or subcutaneous AT of OB/ND patients.

CONCLUSIONS

IMT increased with severe obesity but was not influenced by the degree of systemic inflammation or AT macrophage accumulation.

Perivascular adipose tissue of the descending thoracic aorta is associated with systemic lupus erythematosus and vascular calcification in women

OBJECTIVE

Women with systemic lupus erythematosus (SLE) have an increased risk of cardiovascular disease (CVD). Traditional CVD and SLE-disease related risk factors do not fully account for this increased risk. Perivascular adipose tissue (PVAT) is a visceral adipose depot in close proximity to blood vessels possibly influencing CVD. We hypothesized that women with SLE have an increased volume of descending thoracic aortic PVAT (aPVAT) associated with increased vascular calcification.

METHODS

Using electron beam computed tomography, we quantified the aPVAT in clinically CVD-free SLE women (n = 135) and age-/race-matched healthy controls (HC, n = 152). Coronary artery calcification (CAC) and aortic calcification (AC) were quantified using Agatston scores and the aPVAT was quantified using standard Hounsfield Units (HU) for adipose tissue.

RESULTS

Women with SLE had greater median aPVAT (32.2 cm(3) vs HC aPVAT 28.6 cm(3), p = 0.0071) and greater median AC (26.0 vs HC AC 6.0, p = 0.0013) than the healthy control women. Total aPVAT (per 25 cm(3)) remained significantly associated with SLE after adjusting for CVD risk factors (Odds Ratio 1.74 [95% Confidence Interval: 1.04-2.9], p = 0.034), but was attenuated when adjusting for circulating inflammatory markers (p = 0.34). In a logistic regression analysis, SLE aPVAT (per 25 cm(3)) was associated with AC (6.78 [2.0-23], p = 0.0019), which remained significant after adjusting for circulating inflammatory markers (p = 0.0074), and CAC (2.66 [1.4-5.0], p = 0.0028).

CONCLUSIONS

Total aPVAT is greater in clinically CVD-free SLE women than in age-/race-matched controls and is associated with calcification in different vascular beds.

Relationships between total and regional adiposity and epicardial fat in obese women: how can dual-energy X-ray absorptiometry be associated with echocardiographic epicardial fat measurements?

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Obesity is an increasingly prevalent metabolic disorder and it is associated with a large number of comorbidities, including cardiovascular diseases. Adipose tissue is an active endocrine organ and its ectopic depots and distribution have different metabolic meanings on risks for health; as a matter of fact, epicardial fat seems to play a specific role in cardiovascular diseases. The use of dual-energy X-ray absorptiometry (DXA) to evaluate and follow-up patients affected by obesity is becoming a very important point in the management of the disease.

WHAT THIS STUDY ADDS

An investigation of the association between epicardial fat and regional adiposity by DXA in female obese patients. The total amount of central (trunk) fat mass is more strongly correlated than android visceral fat mass to epicardial thickness in obese women. In the interpretation of whole-body DXA data, physician should consider trunk fat mass for good and independent predictivity on epicardial fat depots. Our aim was to analyse in a population of obese women the relationship between the amount of epicardial fat as measured by transthoracic echocardiography (US) and the parameters of regional adiposity by dual-energy X-ray absorptiometry (DXA), with particular reference to a new software for visceral fat assessment and to a new 'heart-suited' regions of interests (ROIs). Sixty patients who satisfied technical inclusion criteria underwent whole-body DXA scan and US on the same day. Total and android fat mass (FM) and FM percentage (FM%) were considered as well as visceral fat (VAT) subcompartment in the android region; moreover, six new ROIs were designed on whole-body DXA images for the investigation of adiposity parameters at heart level. US provided epicardial fat thickness (EPI-thickness) and area (EPI-area), as measured following previously validated methods. Body mass index (BMI), gynoid and lower limbs (FM and FM%) were found not statistically correlated with EPI-thickness. The highest correlation was achieved by trunk FM (and FM%, with r = 0.544 and 0.480 respectively, P < 0.001), followed by ROI-1 FM (ROI-1 was drawn following thoroughly the cardiac profile), and android FM. Multivariate analysis including age, weight, BMI, trunk FM and the new ROIs (added one by one), retained in the final model trunk FM. Correlations of DXA with EPI-area were superimposable. In obese women, VAT or other new-designed ROIs are not better correlated than traditional ROIs (i.e. trunk) with epicardial fat amount.

Epicardial fat thickness and left ventricular mass in subjects with adrenal incidentaloma

Emerging evidences indicate that patients diagnosed with adrenal incidentaloma may present with cardiovascular complications. Epicardial fat is known to play a role in left ventricle (LV) changes. Whether epicardial fat can be associated with LV mass (LVM) in patients with incidentaloma is unknown. We test the hypothesis that echocardiographic epicardial fat thickness is independently related to LVM in a well-studied group of subjects with adrenal incidentaloma. 46 consecutive patients (age 59 ± 9 years) with imaging diagnosis of adrenal incidentaloma and 30 healthy controls underwent echocardiogram for epicardial fat thickness and LVM measurement. Non-functional incidentaloma was confirmed in 40 subjects, whereas 6 patients were actually diagnosed with mild Cushing's syndrome. Epicardial fat thickness was significantly higher in patients with incidentaloma and mild Cushing's syndrome when compared to controls, (p < 0.01 for both). LVM(h2.7) was higher in subjects with adrenal incidentaloma than in controls and higher in subjects with mild Cushing's syndrome than in those with adrenal incidentaloma (p < 0.05 and p < 0.01). Multiple regression analysis showed that epicardial fat thickness was the best correlate (R (2) = 0.36, β 2.8, p < 0.01) of LVM in overall study patients. We showed for the first time that (1) epicardial fat thickness and LVM are higher in subjects with adrenal incidentaloma and (2) epicardial fat thickness independently correlates with LVM. Echocardiographic epicardial fat may serve as non-invasive marker of visceral fat and earlier cardiac abnormalities in patients with adrenal incidentaloma.

Relationship between epicardial adipose tissue volume measured using coronary computed tomography angiography and atherosclerotic plaque characteristics in patients with severe coronary artery stenosis

Aim

To investigate the relationship between epicardial adipose tissue (EAT) volume and coronary plaque composition.

Methods

EAT volume (measured using coronary computed tomography angiography) and coronary plaque characteristics were assessed on a per-segment basis (modified 15-segment American College of Cardiology/American Heart Association classification) in patients with severe coronary artery stenosis. Coronary plaques were classified into four types: 1, calcified plaques; 2, mixed plaques (calcification dominant); 3, mixed plaques (non-calcification dominant); and 4, non-calcified plaques. The gold standard for luminal stenosis was conventional coronary angiography.

Results

In 365 patients (mean age 58.7 ± 8.0 years), EAT volume was 169.85 ± 29.94 ml. There were no significant between-group differences in patient characteristics. Statistically significant differences in EAT volume between non-calcified and calcified plaque groups were observed. EAT volume showed a positive correlation with total cholesterol and low-density-lipoprotein cholesterol, and a very weak correlation with age, triglyceride, body mass index and high-density-lipoprotein cholesterol.

Conclusion

EAT volume was higher in the presence of non-calcified and mixed plaques in patients with ≥50% severe coronary artery stenosis.

Ectopic fat and cardiometabolic and vascular risk

Given that the variation in how regional adipose tissue handles and stores excess dietary energy has substantial cardiometabolic implications, ectopic fat distribution might be an important predictor of cardiometabolic and vascular risk, in addition to overall obesity itself. Conceptually, ectopic fat depots may be divided into systemically acting fat depots and locally acting fat depots. Systemically acting fat depots include visceral fat, fat in the liver, muscle, or neck, and subcutaneous fat. Accumulation in the abdominal visceral area, compared with overall obesity, has an equally or more important role in the development of cardiometabolic risk. Fat depots in liver/muscle tissue cause adverse cardiometabolic effects by affecting energy metabolism. Fat depots in lower-body subcutaneous areas may be protective regarding cardiometabolic risk, by trapping remnant energy. Fat accumulation in the neck is a unique type of fat depot that may increase cardiovascular risk by increasing insulin resistance. Locally acting fat depots include pericardial fat, perivascular fat, and renal sinus fat. These fat depots have effects primarily on adjacent anatomic organs, directly via lipotoxicity and indirectly via cytokine secretion. Pericardial fat is associated with coronary atherosclerosis. Perivascular fat may play an independent role in adverse vascular biology, including arterial stiffness. Renal sinus fat is a unique fat depot that may confer additional cardiometabolic risk. Thus, ectopic fat depots may contribute to the understanding of the link between body composition and cardiometabolic risk. In this review, we focus on the role and clinical implications of ectopic fat depots in cardiometabolic and vascular risk.

Ambient fine particulate matter and ozone exposures induce inflammation in epicardial and perirenal adipose tissues in rats fed a high fructose diet

Background

Inflammation and oxidative stress play critical roles in the pathogenesis of inhaled air pollutant-mediated metabolic disease. Inflammation in the adipose tissues niches are widely believed to exert important effects on organ dysfunction. Recent data from both human and animal models suggest a role for inflammation and oxidative stress in epicardial adipose tissue (EAT) as a risk factor for the development of cardiovascular disease. We hypothesized that inhalational exposure to concentrated ambient fine particulates (CAPs) and ozone (O₃) exaggerates inflammation and oxidative stress in EAT and perirenal adipose tissue (PAT).

Methods

Eight- week-old Male Sprague–Dawley rats were fed a normal diet (ND) or high fructose diet (HFr) for 8 weeks, and then exposed to ambient AIR, CAPs at a mean of 356 μg/m³, O₃ at 0.485 ppm, or CAPs (441 μg/m³) + O₃ (0.497 ppm) in Dearborn, MI, 8 hours/day, 5 days/week, for 9 days over 2 weeks.

Results

EAT and PAT showed whitish color in gross, and less mitochondria, higher mRNA expression of white adipose specific and lower brown adipose specific genes than in brown adipose tissues. Exposure to CAPs and O₃ resulted in the increase of macrophage infiltration in both EAT and PAT of HFr groups. Proinflammatory genes of Tnf-α, Mcp-1 and leptin were significantly upregulated while IL-10 and adiponectin, known as antiinflammatory genes, were reduced after the exposures. CAPs and O₃ exposures also induced an increase in inducible nitric oxide synthase (iNOS) protein expression, and decrease in mitochondrial area in EAT and PAT. We also found significant increases in macrophages of HFr-O₃ rats. The synergetic interaction of HFr and dirty air exposure on the inflammation was found in most of the experiments. Surprisingly, exposure to CAPs or O₃ induced more significant inflammation and oxidative stress than co-exposure of CAPs and O₃ in EAT and PAT.

Conclusion

EAT and PAT are both white adipose tissues. Short-term exposure to CAPs and O₃, especially with high fructose diet, induced inflammation and oxidative stress in EAT and PAT in rats. These findings may provide a link between air-pollution exposure and accelerated susceptibility to cardiovascular disease and metabolic complications.

Childhood obesity and cardiovascular dysfunction

Obesity-related cardiovascular disease in children is becoming more prevalent in conjunction with the rise in childhood obesity. Children with obesity are predisposed to an increased risk of cardiovascular morbidity and mortality in adulthood. Importantly, research in children with obesity over the last decade has demonstrated that children may exhibit early signs of cardiovascular dysfunction as a result of their excess adiposity, often independent of other obesity-related comorbidities such as dyslipidemia and insulin resistance. The clinical evidence is accumulating to suggest that the cardiovascular damage, once observed only in adults, is also occurring in obese children. The objective of this review is to provide a synopsis of the current research on cardiovascular abnormalities in children with obesity and highlight the importance and need for early detection and prevention programs to mitigate this potentially serious health problem.

Echocardiographically measured epicardial fat predicts restenosis after coronary stenting

OBJECTIVE

Epicardial adipose tissue (EAT), deposited around subepicardial coronary vessels, may contribute directly to perivascular inflammation and smooth muscle cell proliferation. This study assessed the relationship between EAT and in-stent restenosis.

METHODS

Four hundred and seven patients had received successful coronary intervention. EAT thickness was measured by echocardiography. Angiographic follow-up was obtained between 6 months and 2 years. Restenosis was defined as target lesion revascularization (TLR). EAT thickness of patients was compared by TLR controlling for additional well-known predictors of restenosis. The TLR-free survival analysis according to EAT thickness was estimated using the Kaplan-Meier method and the differences between groups were assessed by the log-rank test.

RESULTS

Median EAT thickness was significantly increased in patients undergoing TLR compared with those without restenosis (3.7 vs. 3.0 mm, p = 0.001). EAT thickness was one of the independent factors associated with restenosis (Odds ratio = 1.19, 95% confidence interval = 1.01-1.33, p = 0.007). The TLR-free survival of patients with thick EAT was significantly worse than patients with thin EAT (log-rank p = 0.001).

CONCLUSIONS

EAT thickness is related with restenosis and may provide additional information for future restenosis.

The Norwegian Stroke in the Young Study (NOR-SYS): rationale and design

BACKGROUND

Ischemic stroke in young adults is a major health problem being associated with a higher vascular morbidity and mortality compared to controls, and a stroke recurrence rate of 25% during the first decade. The assumed cause of infarction and the detected risk factors determine the early- and long-term treatment. However, for many patients the cause of stroke remains unknown. Risk factor profile and etiology differ in young and elderly ischemic stroke patients, and atherosclerosis is the determined underlying condition in 10 to 15%. However, subclinical atherosclerosis is probably more prevalent and may go unrecognized.

METHODS/DESIGN

NOR-SYS is a prospective long-term research program. Standardized methods are used for anamnestic, clinical, laboratory, imaging, and ultrasound data collection in ischemic stroke patients aged ≤60 years, their partners and joint adult offspring. The ultrasound protocol includes the assessment of intracranial, carotid and femoral arteries, abdominal aorta, and the estimation of VAT. To date, the study is a single centre study with approximately 400 patients, 250 partners and 350 adult offspring expected to be recruited at our site.

DISCUSSION

NOR-SYS aims to increase our knowledge about heredity and the development of arterial vascular disease in young patients with ischemic stroke and their families. Moreover, optimization of diagnostics, prophylaxis and early intervention are major targets with the intention to reduce stroke recurrence and other clinical arterial events, physical disability, cognitive impairment and death.

The normal limits, subclinical significance, related metabolic derangements and distinct biological effects of body site-specific adiposity in relatively healthy population

Background

The accumulation of visceral adipose tissue that occurs with normal aging is associated with increased cardiovascular risks. However, the clinical significance, biological effects, and related cardiometabolic derangements of body-site specific adiposity in a relatively healthy population have not been well characterized.

Materials and Methods

In this cross-sectional study, we consecutively enrolled 608 asymptomatic subjects (mean age: 47.3 years, 27% female) from 2050 subjects undergoing an annual health survey in Taiwan. We measured pericardial (PCF) and thoracic peri-aortic (TAT) adipose tissue volumes by 16-slice multi-detector computed tomography (MDCT) (Aquarius 3D Workstation, TeraRecon, San Mateo, CA, USA) and related these to clinical characteristics, body fat composition (Tanita 305 Corporation, Tokyo, Japan), coronary calcium score (CCS), serum insulin, high-sensitivity C-reactive protein (Hs-CRP) level and circulating leukocytes count. Metabolic risk was scored by Adult Treatment Panel III guidelines.

Results

TAT, PCF, and total body fat composition all increased with aging and higher metabolic scores (all p<0.05). Only TAT, however, was associated with higher circulating leukocyte counts (ß-coef.:0.24, p<0.05), serum insulin (ß-coef.:0.17, p<0.05) and high sensitivity C-reactive protein (ß-coef.:0.24, p<0.05). These relationships persisted after adjustment in multivariable models (all p<0.05). A TAT volume of 8.29 ml yielded the largest area under the receiver operating characteristic curve (AUROC: 0.79, 95%CI: 0.74–0.83) to identify metabolic syndrome. TAT but not PCF correlated with higher coronary calcium score after adjustment for clinical variables (all p<0.05).

Conclusion

In our study, we observe that age-related body-site specific accumulation of adipose tissue may have distinct biological effects. Compared to other adiposity measures, peri-aortic adiposity is more tightly associated with cardiometabolic risk profiles and subclinical atherosclerosis in a relatively healthy population.