Epicardial adipose tissue: at the heart of the obesity complications

Female obesity: clinical and psychological assessment toward the best treatment

Obesity is a heterogeneous condition which results from complex interactions among sex/gender, sociocultural, environmental, and biological factors. Obesity is more prevalent in women in most developed countries, and several clinical and psychological obesity complications show sex-specific patterns. Females differ regarding fat distribution, with males tending to store more visceral fat, which is highly correlated to increased cardiovascular risk. Although women are more likely to be diagnosed with obesity and appear more motivated to lose weight, as confirmed by their greater representation in clinical trials, males show better outcomes in terms of body weight and intra-abdominal fat loss and improvements in the metabolic risk profile. However, only a few relatively recent studies have investigated gender differences in obesity, and sex/gender is rarely considered in the assessment and management of the disease. This review summarizes the evidence of gender differences in obesity prevalence, contributing factors, clinical complications, and psychological challenges. In addition, we explored gender differences in response to obesity treatments in the specific context of new anti-obesity drugs.

Empagliflozin to elderly and obese patients with increased risk of developing heart failure: Study protocol for the Empire Prevent trial program

INTRODUCTION

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have previously demonstrated cardioprotective properties in patients with type 2 diabetes, suggesting a preventive effect on heart failure (HF). The Empire Prevent trial program investigates the therapeutic potential for HF prevention by evaluating the cardiac, metabolic, and renal effects of the SGLT2 inhibitor empagliflozin in patients with increased risk of developing HF, but without diabetes or established HF.

METHODS

The Empire Prevent trial program is an investigator-initiated, double-blind, randomized clinical trial program including elderly and obese patients (60-84 years, body mass index >28 kg/m2) with at least one manifestation of hypertension, cardiovascular or chronic kidney disease, but no history of diabetes or HF. The aims are to investigate the effects of empagliflozin on 1) physical capacity and left ventricular and atrial structural changes with peak oxygen consumption and left ventricular mass as primary endpoints (Empire Prevent Cardiac), and 2) cardiac-adipose tissue interaction and volume homeostasis with primary endpoints of changes in epicardial adipose tissue and estimated extracellular volume (Empire Prevent Metabolic). At present, 138 of 204 patients have been randomized in the Empire Prevent trial program. Patients are randomized 1:1 to 180 days treatment with empagliflozin 10 mg daily or placebo, while undergoing a comprehensive examination program at baseline and follow-up.

DISCUSSION

The Empire Prevent trial program will mark the first step towards elucidating the potential of SGLT2 inhibition for HF prevention in an outpatient setting in elderly and obese patients with increased risk of developing HF, but with no history of diabetes or established HF. Furthermore, the Empire Prevent trial program will supplement the larger event-driven trials by providing mechanistic insights to the beneficial effects of SGLT2 inhibition.

TRIAL REGISTRATION

Both parts of the trial program have been registered on September 13th 2021 (Clinical Trial Registration numbers: NCT05084235 and NCT05042973) before enrollment of the first patient. All patients will provide oral and written informed consent. The trial is approved by The Regional Committee on Health Research Ethics and the Danish Medicines Agency. Data will be disseminated through scientific meetings and peer-reviewed journals irrespective of outcome.

Increase of Epicardial Adipose Tissue (EAT) With Fat Infiltration of Right Ventricular Myocardium: Is it Always a High-Risk Stigmata or a Worrisome Feature?

Incidental epicardial adipose tissue (EAT) and subepicardial fat infiltration on CT scans are not uncommon and the differential diagnosis can be a challenge. Considering the vastness of the possible disorders, it is important to differentiate physiologic age-related condition from pathologic disease. We present a case of an asymptomatic 81-year-old woman in which according to ECG and CMR findings we considered as possible differential diagnoses arrhythmogenic cardiomyopathy (ACM) dominant-right variant, lipomatosis and physiological growth of epicardial fat. We focus on patient characteristics, location of the fat replacement, heart morphovolumetry, wall motion of the ventricles and absence of late gadolinium enhancement to diagnose pericardial fat hypertrophy and physiological fatty infiltration. The role of EAT is unclear and it could play a part in the development of atherosclerosis and atrial fibrillation. Therefore, the clinicians should not underestimate this condition even if it would be an incidental finding in asymptomatic patients.

Visceral adipose tissue and residual cardiovascular risk: a pathological link and new therapeutic options

Obesity is a heterogeneous disease that affects almost one-third of the global population. A clear association has been established between obesity and cardiovascular disease (CVD). However, CVD risk is known to be related more to the local distribution of fat than to total body fat. Visceral adipose tissue (VAT) in particular has a high impact on CVD risk. This manuscript reviews the role of VAT in residual CV risk and the available therapeutic strategies for decreasing residual CV risk related to VAT accumulation. Among the many pathways involved in residual CV risk, obesity and particularly VAT accumulation play a major role by generating low-grade systemic inflammation, which in turn has a high prognostic impact on all-cause mortality and myocardial infarction. In recent years, many therapeutic approaches have been developed to reduce body weight. Orlistat was shown to reduce both weight and VAT but has low tolerability and many drug-drug interactions. Naltrexone-bupropion combination lowers body weight but has frequent side effects and is contraindicated in patients with uncontrolled hypertension. Liraglutide and semaglutide, glucagon-like peptide 1 (GLP-1) agonists, are the latest drugs approved for the treatment of obesity, and both have been shown to induce significant body weight loss. Liraglutide, semaglutide and other GLP-1 agonists also showed a positive effect on CV outcomes in diabetic patients. In addition, liraglutide showed to specifically reduce VAT and inflammatory biomarkers in obese patients without diabetes. GLP-1 agonists are promising compounds to limit inflammation in human visceral adipocytes.

The Crosstalk between Gut Microbiota and White Adipose Tissue Mitochondria in Obesity

Adipose tissue (AT) dysregulation is a key process in the pathophysiology of obesity and its cardiometabolic complications, but even if a growing body of evidence has been collected over recent decades, the underlying molecular basis of adiposopathy remains to be fully understood. In this context, mitochondria, the intracellular organelles that orchestrate energy production and undergo highly dynamic adaptive changes in response to changing environments, have emerged as crucial regulators of both white (WAT) and brown adipose tissue (BAT) metabolism and function. Given that the gut microbiota and its metabolites are able to regulate host metabolism, adipogenesis, WAT inflammation, and thermogenesis, we hypothesize that their frequently observed dysregulation in obesity could affect AT metabolism by exerting direct and indirect effects on AT mitochondria. By collecting and revising the current evidence on the connections between gut microbiota and AT mitochondria in obesity, we gained insights into the molecular biology of their hitherto largely unexplored crosstalk, tracing how gut microbiota may regulate AT mitochondrial function.

Pioglitazone reduces epicardial fat and improves diastolic function in patients with type 2 diabetes

AIMS

To examine the effect of pioglitazone on epicardial (EAT) and paracardial adipose tissue (PAT) and measures of diastolic function and insulin sensitivity in patients with type 2 diabetes mellitus (T2DM).

METHODS

Twelve patients with T2DM without clinically manifest cardiovascular disease and 12 subjects with normal glucose tolerance (NGT) underwent cardiac magnetic resonance imaging to quantitate EAT and PAT and diastolic function before and after pioglitazone treatment for 24 weeks. Whole-body insulin sensitivity was measured with a euglycaemic insulin clamp and the Matsuda Index (oral glucose tolerance test).

RESULTS

Pioglitazone reduced glycated haemoglobin by 0.9% (P < 0.05), increased HDL cholesterol by 7% (P < 0.05), reduced triacylglycerol by 42% (P < 0.01) and increased whole-body insulin-stimulated glucose uptake by 71% (P < 0.01) and Matsuda Index by 100% (P < 0.01). In patients with T2DM, EAT (P < 0.01) and PAT (P < 0.01) areas were greater compared with subjects with NGT, and decreased by 9% (P = 0.03) and 9% (P = 0.09), respectively, after pioglitazone treatment. Transmitral E/A flow rate and peak left ventricular flow rate (PLVFR) were reduced in T2DM versus NGT (P < 0.01) and increased following pioglitazone treatment (P < 0.01-0.05). At baseline normalized PLVFR inversely correlated with EAT (r = -0.45, P = 0.03) but not PAT (r = -0.29, P = 0.16). E/A was significantly and inversely correlated with EAT (r = -0.55, P = 0.006) and PAT (r = -0.40, P = 0.05). EAT and PAT were inversely correlated with whole-body insulin-stimulated glucose uptake (r = -0.68, P < 0.001) and with Matsuda Index (r = 0.99, P < 0.002).

CONCLUSION

Pioglitazone reduced EAT and PAT areas and improved left ventricular (LV) diastolic function in T2DM. EAT and PAT are inversely correlated (PAT less strongly) with LV diastolic function and both EAT and PAT are inversely correlated with measures of insulin sensitivity.

Palmitic acid methyl ester induces cardiac hypertrophy through activating the GPR receptor-mediated changes of intracellular calcium concentrations and mitochondrial functions

Myocardial hypertrophy is associated with a significant increase in intracellular Ca²⁺ , which can be induced by long-chain fatty acid. Palmitic acid methyl ester (PAME), a fatty acid ester released from adipose tissue, superior cervical ganglion, and retina, has been found to have anti-inflammation, antifibrosis, and peripheral vasodilation effects. However, the effects of PAME on cardiomyocytes are still unclear. The aim of this study was to determine whether PAME could disrupt the intracellular Ca²⁺ balance, leading to cardiomyocyte hypertrophy. Neonatal rat cardiomyocytes were treated with various concentrations (10-100 μM) of PAME for 1-4 days. Cytosolic Ca²⁺ and mitochondrial Ca²⁺ concentrations were examined using Fura-2 AM and Rhod-2, respectively. After treatment with PAME for 4 days, mitochondrial Ca²⁺ , an indicator of the state of mitochondrial permeability transition pore (MPTP), and cell death were monitored by flow cytometric analysis. ATP levels were detected using the ATP assay kit. Cardiomyocyte hypertrophy was analyzed by measuring the cardiac hypertrophy biomarker and cell area using quantitative real time-polymerase chain reaction, Western Blot analysis and immunofluorescence analysis. Our results show that PAME concentration- and time-dependently increased cytosolic and mitochondria Ca²⁺ through the mitochondrial calcium uniporter. Moreover, treatment with PAME for 4 days caused MPTP opening, thereby reducing ATP production and enhancing reactive oxygen species (ROS) generation, and finally led to cardiomyocyte hypertrophy. These effects caused by PAME treatment were attenuated by the G-protein coupled receptor 40 (GPR40) inhibitor. In conclusion, PAME impaired mitochondrial function, which in turn led to cardiomyocyte hypertrophy through increasing the mitochondrial Ca²⁺ levels mediated by activating the GPR40 signaling pathway.

Cellular cross talk between epicardial fat and cardiovascular risk

A variety of fat compartments have several local and systemic effect and play a crucial role in the maintenance of health and development of disease. For the past few years, special attention has been paid to epicardial fat. It is the visceral fat compartment of the heart and has several local and systemic effects. It can perform a role in the development of cardiometabolic risk. The epicardial adipose tissue (EAT) is a unique and multifunctional fat compartment of the heart. It is located between the myocardium and the visceral pericardium. During normal physiological conditions, the EAT has metabolic, thermogenic, and mechanical (cardioprotective) characteristics. The EAT can produce several adipocytokines and chemokines depending on microenvironments. It can influence through paracrine and vasocrine mechanism and participate in the development and progression of cardiovascular (CVS) diseases. In addition, metabolic disease leads to changes in both thickness and volume of the EAT, and it can modify the structure and the function of heart. It has been associated with various CVS diseases such as, cardiomyopathy, atrial fibrillation, and coronary artery disease. Therefore, EAT is a potential therapeutic target for CVS risk.

The association between the hypertriglyceridaemia waist phenotype, cardiovascular risk factors and the metabolic syndrome in South African Asian-Indians

BACKGROUND AND AIMS

The combination of high triglycerides and increased waist circumference (HTGW) has not been examined as a predictor of cardiometabolic abnormalities or the metabolic syndrome (MetS) in high-risk Asian populations. This study examines the so-called hypertriglyceridemia waist (HTGW) phenotype, (high serum triglycerides [Tg]) and increased waist circumference (WC) as a predictor of cardiometabolic abnormalities in a high-risk Asian population.

METHODS

Data from the Phoenix Lifestyle Project, a cross-sectional study of 1349 South Asian Indians (15-65 years; 379 men; 970 women) in Durban, KwaZulu-Natal, were reclassified into different waist and Tg phenotypes using the demographic, anthropometric, and biochemical parameters. The HTGW phenotype was defined as WC ≥ 90 cm for men; ≥80 cm for women & TG ≥ 1.7 mmol/L. The MetS was determined using the harmonised criteria. Stepwise logistic regression was used to determine the strength of each phenotype as a predictor of the MetS.

RESULTS

The HTGW phenotype was recorded in 35.4% of participants, predominantly women (36.1%) and 8.2% smokers. Metabolic derangements and cardiovascular risk factors increased significantly in those with HTGW phenotype. After adjustment, multivariate logistic regression showed that the association between elevated total serum cholesterol, LDL, lowered HDL, diabetes and hypertension with HTGW persisted. The odds for participants with the HTGW phenotype developing the MetS was 19.7 (95% CI 13.9; 27.9). The degree of concordance between the HTGW was highest with the IDF and harmonised criteria for MetS.

CONCLUSION

The HTGW phenotype was associated with a significantly higher risk of developing additional lipid derangements, hypertension, diabetes and the MetS.

Epicardial Adipose Tissue as an Independent Cardiometabolic Risk Factor for Coronary Artery Disease

During the last decades, visceral adiposity has been at the forefront of scientific research because of its complex role in the pathogenesis of cardiovascular diseases. Epicardial adipose tissue (EAT) is the visceral lipid compartment between the myocardium and the visceral pericardium. Due to their unobstructed anatomic vicinity, epicardial fat and myocardium are nourished by the same microcirculation. It is widely known that EAT serves as an energy lipid source and thermoregulator for the human heart. In addition to this, epicardial fat exerts highly protective effects since it releases a great variety of anti-inflammatory molecules to the adjacent cardiac muscle. Taking into account the unique properties of human EAT, it is undoubtedly a key factor in cardiac physiology since it facilitates complex heart functions. Under pathological circumstances, however, epicardial fat promotes coronary atherosclerosis in a variety of ways. Therefore, the accurate estimation of epicardial fat thickness and volume could be utilized as an early detecting method and future medication target for coronary artery disease (CAD) elimination. Throughout the years, several therapeutic approaches for dysfunctional human EAT have been proposed. A balanced healthy diet, aerobic and anaerobic physical activity, bariatric surgery, and pharmacological treatment with either traditional or novel antidiabetic and antilipidemic drugs are some of the established medical approaches. In the present article, we review the current knowledge regarding the anatomic and physiological characteristics of epicardial fat. In addition to this, we describe the pathogenic mechanisms which refer to the crosstalk between epicardial fat alteration and coronary arterial atherosclerosis development. Lastly, we present both lifestyle and pharmacological methods as possible treatment options for EAT dysfunction.

Relationship between Epicardial and Coronary Adipose Tissue and the Expression of Adiponectin, Leptin, and Interleukin 6 in Patients with Coronary Artery Disease

Adipose tissue (AT) is an endocrine and paracrine organ that synthesizes biologically active adipocytokines, which affect inflammation, fibrosis, and atherogenesis. Epicardial and perivascular fat depots are of great interest to researchers, owing to their potential effects on the myocardium and blood vessels. The aim of the study was to assess the expression and secretion of adipocytokine genes in the AT of patients with coronary artery disease (CAD) and patients with aortic or mitral valve replacement. This study included 84 patients with CAD and 50 patients with aortic or mitral valve replacement. Adipocytes were isolated from subcutaneous, epicardial (EAT), and perivascular AT (PVAT), and were cultured for 24 h. EAT exhibited the lowest level of adiponectin gene expression and secretion, regardless of nosology, and high expression levels of the leptin gene and interleukin-6 (IL-6). However, EAT adipocytes in patients with CAD were characterized by more pronounced changes in comparison with the group with heart defects. High leptin and IL-6 levels resulted in increased pro-inflammatory activity, as observed in both EAT and PVAT adipocytes, especially in individuals with CAD. Therefore, our results revealed the pathogenetic significance of alterations in the adipokine and cytokine status of adipocytes of EAT and PVAT in patients with CAD.

Physical Exercise Potentially Targets Epicardial Adipose Tissue to Reduce Cardiovascular Disease Risk in Patients with Metabolic Diseases: Oxidative Stress and Inflammation Emerge as Major Therapeutic Targets

Excess epicardial adiposity, within a state of obesity and metabolic syndrome, is emerging as an important risk factor for the development of cardiovascular diseases (CVDs). Accordingly, increased epicardial fat thickness (EFT) implicates the exacerbation of pathological mechanisms involving oxidative stress and inflammation within the heart, which may accelerate the development of CVDs. This explains increased interest in targeting EFT reduction to attenuate the detrimental effects of oxidative stress and inflammation within the setting of metabolic syndrome. Here, we critically discuss clinical and preclinical evidence on the impact of physical exercise on EFT in correlation with reduced CVD risk within a setting of metabolic disease. This review also brings a unique perspective on the implications of oxidative stress and inflammation as major pathological consequences that link increased EFT to accelerated CVD risk in conditions of metabolic disease.

Reciprocal organ interactions during heart failure: a position paper from the ESC Working Group on Myocardial Function

Heart failure-either with reduced or preserved ejection fraction (HFrEF/HFpEF)-is a clinical syndrome of multifactorial and gender-dependent aetiology, indicating the insufficiency of the heart to pump blood adequately to maintain blood flow to meet the body's needs. Typical symptoms commonly include shortness of breath, excessive fatigue with impaired exercise capacity, and peripheral oedema, thereby alluding to the fact that heart failure is a syndrome that affects multiple organ systems. Patients suffering from progressed heart failure have a very limited life expectancy, lower than that of numerous cancer types. In this position paper, we provide an overview regarding interactions between the heart and other organ systems, the clinical evidence, underlying mechanisms, potential available or yet-to-establish animal models to study such interactions and finally discuss potential new drug interventions to be developed in the future. Our working group suggests that more experimental research is required to understand the individual molecular mechanisms underlying heart failure and reinforces the urgency for tailored therapeutic interventions that target not only the heart but also other related affected organ systems to effectively treat heart failure as a clinical syndrome that affects and involves multiple organs.

Atherosclerosis Pathways are Activated in Pericoronary Adipose Tissue of Patients with Coronary Artery Disease

PURPOSE

Perivascular release of inflammatory mediators may accelerate coronary lesion formation and contribute to plaque instability. Accordingly, we compared gene expression in pericoronary adipose tissue (PCAT) in patients with advanced coronary artery disease (CAD) and non-CAD controls.

PATIENTS AND METHODS

PCAT samples were collected during coronary bypass grafting from CAD patients (n = 21) and controls undergoing valve replacement surgery, with CAD excluded by coronary angiography (n = 19). Gene expression was measured by GeneChip™ Human Transcriptome Array 2.0. Obtained list of 1348 transcripts (2.0%) that passed the filter criteria was further analyzed by Ingenuity Pathway Analysis software, identifying 735 unique differentially expressed genes (DEGs).

RESULTS

Among the CAD patients, 416 (30.9%) transcripts were upregulated, and 932 (69.1%) were downregulated, compared to controls. The top upregulated genes were involved in inflammation and atherosclerosis (chemokines, interleukin-6, selectin E and low-density lipoprotein cholesterol (LDL-C) receptor), whereas the downregulated genes were involved in cardiac ischaemia and remodelling, platelet function and mitochondrial function (miR-3671, miR-4524a, multimerin, biglycan, tissue factor pathway inhibitor (TFPI), glucuronidases, miR-548, collagen type I, III, IV). Among the top upstream regulators, we identified molecules that have proinflammatory and atherosclerotic features (High Mobility Group Box 2 (HMGB2), platelet-derived growth platelet (PDGF) and evolutionarily conserved signaling intermediate in Toll pathways (ESCIT)). The activated pathway related to DEGs consisted of molecules with well-established role in the pathogenesis of atherosclerosis (TFPI, plasminogen activator, plasminogen activator, urokinase receptor (PLAUR), thrombomodulin). Moreover, we showed that 22 of the altered genes form a pro-atherogenic network.

CONCLUSION

Altered gene expression in PCAT of CAD patients, with genes upregulation and activation of pathway involved in inflammation and atherosclerosis, may be involved in CAD development and progression.

New Peptides as Potential Players in the Crosstalk Between the Brain and Obesity, Metabolic and Cardiovascular Diseases

According to the World Health Organization report published in 2016, 650 million people worldwide suffer from obesity, almost three times more than in 1975. Obesity is defined as excessive fat accumulation which may impair health with non-communicable diseases such as diabetes, cardiovascular diseases (hypertension, coronary artery disease, stroke), and some cancers. Despite medical advances, cardiovascular complications are still the leading causes of death arising from obesity. Excessive fat accumulation is caused by the imbalance between energy intake and expenditure. The pathogenesis of this process is complex and not fully understood, but current research is focused on the role of the complex crosstalk between the central nervous system (CNS), neuroendocrine and immune system including the autonomic nervous system, adipose tissue, digestive and cardiovascular systems. Additionally, special attention has been paid to newly discovered substances: neuropeptide 26RFa, preptin, and adropin. It was shown that the above peptides are synthesized both in numerous structures of the CNS and in many peripheral organs and tissues, such as the heart, adipose tissue, and the gastrointestinal tract. Recently, particular attention has been paid to the role of the presented peptides in the pathogenesis of obesity, metabolic and cardiovascular system diseases. This review summarizes the role of newly investigated peptides in the crosstalk between brain and peripheral organs in the pathogenesis of obesity, metabolic, and cardiovascular diseases.

Cardiac magnetic resonance imaging: insights into developmental programming and its consequences for aging

Cardiovascular diseases (CVD) are important consequences of adverse perinatal conditions such as fetal hypoxia and maternal malnutrition. Cardiac magnetic resonance imaging (CMR) can produce a wealth of physiological information related to the development of the heart. This review outlines the current state of CMR technologies and describes the physiological biomarkers that can be measured. These phenotypes include impaired ventricular and atrial function, maladaptive ventricular remodeling, and the proliferation of myocardial steatosis and fibrosis. The discussion outlines the applications of CMR to understanding the developmental pathways leading to impaired cardiac function. The use of CMR, both in animal models of developmental programming and in human studies, is described. Specific examples are given in a baboon model of intrauterine growth restriction (IUGR). CMR offers great potential as a tool for understanding the sequence of dysfunctional adaptations of developmental origin that can affect the human cardiovascular system.

Intraperitoneal, but not retroperitoneal, visceral adipose tissue is associated with diabetes mellitus: a cross-sectional, retrospective pilot analysis

AIM

Diabetes mellitus (DM) is associated with adverse outcomes, and visceral adipose tissue (VAT), classified into intraperitoneal VAT (IVAT) and retroperitoneal VAT (RVAT), is associated with insulin resistance. This study aimed to evaluate the association of IVAT and RVAT with the prevalence or incidence of DM.

METHODS

In this cross-sectional, retrospective, cohort study, the prevalence and incidence of DM was analyzed in 803 and 624 middle-aged Japanese participants, respectively. The cross-sectional area of the abdominal adipose tissue was evaluated from an unenhanced computed tomography scan at the third lumbar vertebrae, and the IVAT or RVAT was analyzed using specialized software. The areas were normalized for the square value of the participants' height in meters and described as the IVAT or RVAT area index.

RESULTS

The IVAT area index (adjusted odds ratio [OR], 1.04; 95% confidence intervals [CI], 1.02-1.07, per 1.0 cm²/m²) or IVAT/RVAT area ratio (1.89; 1.23-2.85, per 1.0) was independently associated with the prevalence of DM, whereas the RVAT area index was not. During a follow-up (mean) of 3.7 years, 30 participants were diagnosed with DM. The IVAT area index (adjusted hazards ratio [HR], 1.02; 95% CI 1.003-1.04, per 1.0 cm²/m²) or IVAT/RVAT area ratio (2.25; 1.40-3.43, per 1.0) was independently associated with the incidence of DM, whereas the RVAT area index was not.

CONCLUSIONS

IVAT, but not RVAT, is associated with the prevalence or incidence of DM.

Nutrigenetics-personalized nutrition in obesity and cardiovascular diseases

Epidemiological data support the view that both obesity and cardiovascular diseases (CVD) account for a high proportion of total morbidity and mortality in adults throughout the world. Obesity and CVD have complex interplay mechanisms of genetic and environmental factors, including diet. Nutrition is an environmental factor and it has a predominant and recognizable role in health management and in the prevention of obesity and obesity-related diseases, including CVD. However, there is a marked variation in CVD in patients with obesity and the same dietary pattern. The different genetic polymorphisms could explain this variation, which leads to the emergence of the concept of nutrigenetics. Nutritional genomics or nutrigenetics is the science that studies and characterizes gene variants associated with differential response to specific nutrients and relating this variation to various diseases, such as CVD related to obesity. Thus, the personalized nutrition recommendations, based on the knowledge of an individual's genetic background, might improve the outcomes of a specific dietary intervention and represent a new dietary approach to improve health, reducing obesity and CVD. Given these premises, it is intuitive to suppose that the elucidation of diet and gene interactions could support more specific and effective dietary interventions in both obesity and CVD prevention through personalized nutrition based on nutrigenetics. This review aims to briefly summarize the role of the most important genes associated with obesity and CVD and to clarify the knowledge about the relation between nutrition and gene expression and the role of the main nutrition-related genes in obesity and CVD.

Obesity Phenotypes, Diabetes, and Cardiovascular Diseases

This review addresses the interplay between obesity, type 2 diabetes mellitus, and cardiovascular diseases. It is proposed that obesity, generally defined by an excess of body fat causing prejudice to health, can no longer be evaluated solely by the body mass index (expressed in kg/m²) because it represents a heterogeneous entity. For instance, several cardiometabolic imaging studies have shown that some individuals who have a normal weight or who are overweight are at high risk if they have an excess of visceral adipose tissue-a condition often accompanied by accumulation of fat in normally lean tissues (ectopic fat deposition in liver, heart, skeletal muscle, etc). On the other hand, individuals who are overweight or obese can nevertheless be at much lower risk than expected when faced with excess energy intake if they have the ability to expand their subcutaneous adipose tissue mass, particularly in the gluteal-femoral area. Hence, excessive amounts of visceral adipose tissue and of ectopic fat largely define the cardiovascular disease risk of overweight and moderate obesity. There is also a rapidly expanding subgroup of patients characterized by a high accumulation of body fat (severe obesity). Severe obesity is characterized by specific additional cardiovascular health issues that should receive attention. Because of the difficulties of normalizing body fat content in patients with severe obesity, more aggressive treatments have been studied in this subgroup of individuals such as obesity surgery, also referred to as metabolic surgery. On the basis of the above, we propose that we should refer to obesities rather than obesity.

Expression of Sfrp5/Wnt5a in human epicardial adipose tissue and their relationship with coronary artery disease

Secreted frizzled-related protein 5 (Sfrp5) primarily acts in combination with wingless-type family member 5a (Wnt5a), to inhibits chronic inflammation and repress atherosclerosis and other metabolic disorders. Epicardial adipose tissue (EAT), surrounding the heart and coronary arteries, has been found to be highly related to the progression of coronary artery disease through adipokines production. However, little is known about EAT-derived Sfrp5 and Wnt5a in humans. We aimed to investigate whether the EAT-derived Sfrp5/Wnt5a levels are altered in patients with CAD. Fifty-eight patients with CAD and 29 patients without CAD who underwent cardiac surgery were enrolled. Serum samples and paired adipose biopsies from EAT and subcutaneous adipose tissue (SAT) were collected, and Sfrp5 and Wnt5a levels were detected. Correlation and multivariate regression analyses were performed to determine the relationship between Sfrp5/Wnt5a expression and CAD and other clinical risk factors. According to the results, the CAD group had lower Sfrp5 and higher Wnt5a levels in EAT and serum (all p < 0.05). Serum Sfrp5 levels were significantly lower in CAD patients with impaired myocardial function. EAT Sfrp5 mRNA levels and serum Sfrp5 levels were both negatively associated with the presence of CAD, after adjustment for known biomarkers, EAT mRNA and serum Wnt5a levels correlated positively with the presence of CAD. Thus, we concluded that low Sfrp5 and high Wnt5a levels are associated with the presence of CAD, independent of other conventional risk factors.

Correlative Study on Impaired Prostaglandin E2 Regulation in Epicardial Adipose Tissue and its Role in Maladaptive Cardiac Remodeling via EPAC2 and ST2 Signaling in Overweight Cardiovascular Disease Subjects

There is recent evidence that the dysfunctional responses of a peculiar visceral fat deposit known as epicardial adipose tissue (EAT) can directly promote cardiac enlargement in the case of obesity. Here, we observed a newer molecular pattern associated with LV dysfunction mediated by prostaglandin E2 (PGE₂) deregulation in EAT in a cardiovascular disease (CVD) population. A series of 33 overweight CVD males were enrolled and their EAT thickness, LV mass, and volumes were measured by echocardiography. Blood, plasma, EAT, and SAT biopsies were collected for molecular and proteomic assays. Our data show that PGE₂ biosynthetic enzyme (PTGES-2) correlates with echocardiographic parameters of LV enlargement: LV diameters, LV end diastolic volume, and LV masses. Moreover, PTGES-2 is directly associated with EPAC2 gene (r = 0.70, p < 0.0001), known as a molecular inducer of ST2/IL-33 mediators involved in maladaptive heart remodelling. Furthermore, PGE₂ receptor 3 (PTEGER3) results are downregulated and its expression is inversely associated with ST2/IL-33 expression. Contrarily, PGE₂ receptor 4 (PTGER4) is upregulated in EAT and directly correlates with ST2 molecular expression. Our data suggest that excessive body fatness can shift the EAT transcriptome to a pro-tissue remodelling profile, may be driven by PGE₂ deregulation, with consequent promotion of EPAC2 and ST2 signalling.

Stem cells from human cardiac adipose tissue depots show different gene expression and functional capacities

BACKGROUND

The composition and function of the adipose tissue covering the heart are poorly known. In this study, we have investigated the epicardial adipose tissue (EAT) covering the cardiac ventricular muscle and the EAT covering the left anterior descending artery (LAD) on the human heart, to identify their resident stem cell functional activity.

METHODS

EAT covering the cardiac ventricular muscle was isolated from the apex (avoiding areas irrigated by major vessels) of the heart (ventricular myocardium adipose tissue (VMAT)) and from the area covering the epicardial arterial sulcus of the LAD (PVAT) in human hearts excised during heart transplant surgery. Adipose stem cells (ASCs) from both adipose tissue depots were immediately isolated and phenotypically characterized by flow cytometry. The different behavior of these ASCs and their released secretome microvesicles (MVs) were investigated by molecular and cellular analysis.

RESULTS

ASCs from both VMAT (mASCs) and the PVAT (pASCs) were characterized by the expression of CD105, CD44, CD29, CD90, and CD73. The angiogenic-related genes VEGFA, COL18A1, and TF, as well as the miRNA126-3p and miRNA145-5p, were analyzed in both ASC types. Both ASCs were functionally able to form tube-like structures in three-dimensional basement membrane substrates. Interestingly, pASCs showed a higher level of expression of VEGFA and reduced level of COL18A1 than mASCs. Furthermore, MVs released by mASCs significantly induced human microvascular endothelial cell migration.

CONCLUSION

Our study indicates for the first time that the resident ASCs in human epicardial adipose tissue display a depot-specific angiogenic function. Additionally, we have demonstrated that resident stem cells are able to regulate microvascular endothelial cell function by the release of MVs.

The endocrine function of adipose tissues in health and cardiometabolic disease

In addition to their role in glucose and lipid metabolism, adipocytes respond differentially to physiological cues or metabolic stress by releasing endocrine factors that regulate diverse processes, such as energy expenditure, appetite control, glucose homeostasis, insulin sensitivity, inflammation and tissue repair. Both energy-storing white adipocytes and thermogenic brown and beige adipocytes secrete hormones, which can be peptides (adipokines), lipids (lipokines) and exosomal microRNAs. Some of these factors have defined targets; for example, adiponectin and leptin signal through their respective receptors that are expressed in multiple organs. For other adipocyte hormones, receptors are more promiscuous or remain to be identified. Furthermore, many of these hormones are also produced by other organs and tissues, which makes defining the endocrine contribution of adipose tissues a challenge. In this Review, we discuss the functional role of adipose tissue-derived endocrine hormones for metabolic adaptations to the environment and we highlight how these factors contribute to the development of cardiometabolic diseases. We also cover how this knowledge can be translated into human therapies. In addition, we discuss recent findings that emphasize the endocrine role of white versus thermogenic adipocytes in conditions of health and disease.

Sodium-glucose co-transporter-2 inhibitors (SGLT2i) use and risk of amputation: an expert panel overview of the evidence

Sodium-glucose co-transporter-2 inhibitors (SGLT2i) are oral antidiabetic agents that exert their glucose-lowering effect by increasing renal excretion of glucose. These drugs have been reported to beneficially affect cardiovascular (CV) and renal outcomes. However, concerns have recently been raised in relation to increased risk of lower-extremities amputation with canagliflozin and it remains unclear whether and to what extent this side effect could also occur with other SGLT2i. The present expert panel overview focuses on the three SGLT2i available and widely used in the US and Europe, i.e. empagliflozin, canagliflozin and dapagliflozin and only refers briefly to other SGLT2i for which less data are available. The results of large CV outcome trials with these SGLT2i are presented, focusing specifically on the data in relation to amputation risk. The potential pathophysiological mechanisms involved in this side effect are discussed. Furthermore, available data reporting amputation cases in SGLT2i users are critically reviewed. The expert panel concludes that, based on current data, increased amputation risk seems to be related only to canagliflozin, thus representing a drug-effect rather than a SGLT2i class-effect. The exact pathways underlying this drug-induced adverse event, possibly related to off-target drug effects rather than SGLT2 inhibition per se, should be elucidated in future studies. Continuous monitoring and pharmacovigilance is necessary and head to head trials would also be essential to provide definitive conclusions.

Epicardial fat: the role of testosterone and lipid metabolism in a cohort of patients with Klinefelter syndrome

CONTEXT

Klinefelter syndrome (KS), in which subjects have additional copies of X chromosomes, is the most common male sex chromosome abnormality, with a prevalence of 1 in 660 and an incidence of about 1 in 500-700 newborns. Its sign and symptoms include infertility, generally low testosterone levels, and an increased prevalence of obesity and metabolic syndrome. Epicardial fat thickness (EFT) reflects visceral adiposity rather than general obesity.

OBJECTIVE

The aim of this study was to analyze echocardiographic EFT in a cohort of patients with KS in comparison with non-obese and obese euploid controls, and to evaluate its correlation with biochemical parameters.

DESIGN, SETTING AND PARTICIPANTS

Two hundred and twenty-one KS patients referred to our Rare Endocrine Diseases clinic and 77 age-matched controls underwent Doppler echocardiography and a full investigation of anthropometric and body composition, Serum levels of total testosterone (T), estradiol (E2), sex hormone binding globulin (SHBG), fasting plasma glucose, insulin, cholesterol and triglycerides were obtained. All participants underwent dual energy X-ray absorptiometry (DEXA) scan to assess truncal body fat (TrBF).

MAIN OUTCOME MEASURE

EFT, body composition and metabolic parameters in KS patients and how they are affected by genotype.

RESULTS

EFT was greater in KS patients than in healthy non-obese (NOb) controls, but lower than in obese (OB) controls. When KS patients were divided into groups (hypogonadal; eugonadal; receiving testosterone replacement therapy [TRT]), EFT was greater in hypogonadal patients than in NOb controls and eugonadal patients, but showed no difference from the OB controls or TRT patients. Hypogonadal patients showed increased TrBF in comparison with NOb controls and eugonadal and TRT patients, and similar TrBF to OB controls. As expected, there was a strong correlation between BMI and EFT in both KS patients and controls (P < 0.0001). In contrast, there was a strong inverse correlation between testosterone and EFT in the control group, but not in KS patients. EFT was significantly correlated with TrBF in both populations (P < 0.0001). Multivariate analyses showed that the major determinants of both EFT and TrBF were BMI and the presence of KS itself. Testosterone and triglycerides were not included as variables in the models.

CONCLUSION

EFT in hypogonadal KS subjects was similar to that of the obese eugonadal controls. Even though there was a direct correlation between BMI and EFT in both populations, the influence of TrBF on EFT was stronger. The presence of the supernumerary X chromosome appeared to be one of the strongest determinants of EFT and TrBF, independent of testosterone levels.

Emerging measurements of atherosclerosis: extra-media thickness, epicardial adipose tissue, and periarterial adipose tissue intima media adventitia index in morbidly obese patients undergoing bariatric surgery

Introduction

Increased values of emerging fat indices are correlated with increased cardiovascular risk.

Aim

To examine the novel non-invasive predictors of coronary disease, namely the carotid extra-media thickness (EMT), PATIMA, and epicardial adipose tissue (EAT), in a group of patients with morbid obesity.

Material and methods

We examined a group of 40 morbidly obese (OB) patients and a control group (CG). All patients were subjected to anthropometric measurements, as well as laboratory and ultrasound examinations.

Results

EATmean and EMTmean differed significantly between groups (OB vs. CG): 5.09 vs. 3.50 and 808.50 vs. 737.00, p < 0.0001, respectively.

Conclusions

Strong correlations were found between novel non-invasive predictors of coronary disease, namely the carotid extra-media thickness, PATIMA, and epicardial adipose tissue. The above-mentioned fat indices were not found to correlate significantly with BMI or other body weight-related parameters used to assess the adipose tissue content. Further studies are required.

Obesity and cardiovascular disease: revisiting an old relationship

A wealth of clinical and epidemiological evidence has linked obesity to a broad spectrum of cardiovascular diseases (CVD) including coronary heart disease, heart failure, hypertension, stroke, atrial fibrillation and sudden cardiac death. Obesity can increase CVD morbidity and mortality directly and indirectly. Direct effects are mediated by obesity-induced structural and functional adaptations of the cardiovascular system to accommodate excess body weight, as well as by adipokine effects on inflammation and vascular homeostasis. Indirect effects are mediated by co-existing CVD risk factors such as insulin resistance, hyperglycemia, hypertension and dyslipidemia. Adipose tissue (AT) quality and functionality are more relevant aspects for cardiometabolic risk than its total amount. The consequences of maladaptive AT expansion in obesity are local and systemic: the local include inflammation, hypoxia, dysregulated adipokine secretion and impaired mitochondrial function; the systemic comprise insulin resistance, abnormal glucose/lipid metabolism, hypertension, a pro-inflammatory and pro-thrombotic state and endothelial dysfunction, all of which provide linking mechanisms for the association between obesity and CVD. The present narrative review summarizes the major pathophysiological links between obesity and CVD (traditional and novel concepts), analyses the heterogeneity of obesity-related cardiometabolic consequences, and provides an overview of the cardiovascular impact of weight loss interventions.

Linking Arrhythmias and Adipocytes: Insights, Mechanisms, and Future Directions

Obesity and atrial fibrillation have risen to epidemic levels worldwide and may continue to grow over the next decades. Emerging evidence suggests that obesity promotes atrial and ventricular arrhythmias. This has led to trials employing various strategies with the ultimate goal of decreasing the atrial arrhythmic burden in obese patients. The effectiveness of these interventions remains to be determined. Obesity is defined by the expansion of adipose mass, making adipocytes a prime candidate to mediate the pro-arrhythmogenic effects of obesity. The molecular mechanisms linking obesity and adipocytes to increased arrhythmogenicity in both the atria and ventricles remain poorly understood. In this focused review, we highlight areas of potential molecular interplay between adipocytes and cardiomyocytes. The effects of adipocytes may be direct, local or remote. Direct effect refers to adipocyte or fatty infiltration of the atrial and ventricular myocardium itself, possibly causing increased dispersion of normal myocardial electrical signals and fibrotic substrate of adipocytes that promote reentry or adipocytes serving as a direct source of aberrant signals. Local effects may originate from nearby adipose depots, specifically epicardial adipose tissue (EAT) and pericardial adipose tissue, which may play a role in the secretion of adipokines and chemokines that can incite inflammation given the direct contact and disrupt the conduction system. Adipocytes can also have a remote effect on the myocardium arising from their systemic secretion of adipokines, cytokines and metabolites. These factors may lead to mitochondrial dysfunction, oxidative stress, autophagy, mitophagy, autonomic dysfunction, and cardiomyocyte death to ultimately produce a pro-arrhythmogenic state. By better understanding the molecular mechanisms connecting dysfunctional adipocytes and arrhythmias, novel therapies may be developed to sever the link between obesity and arrhythmias.

Epicardial fat in heart failure patients with mid-range and preserved ejection fraction

Aims

Adipose tissue and inflammation may play a role in the pathophysiology of patients with heart failure (HF) with mildly reduced or preserved ejection fraction. We therefore investigated epicardial fat in patients with HF with preserved (HFpEF) and mid‐range ejection fraction (HFmrEF), and related this to co‐morbidities, plasma biomarkers and cardiac structure.

Methods and results

A total of 64 HF patients with left ventricular ejection fraction >40% and 20 controls underwent routine cardiac magnetic resonance examination. Epicardial fat volume was quantified on short‐axis cine stacks covering the entire epicardium and was related to clinical correlates, biomarkers associated with inflammation and myocardial injury, and cardiac function and contractility on cardiac magnetic resonance. HF patients and controls were of comparable age, sex and body mass index. Total epicardial fat volume was significantly higher in HF patients compared to controls (107 mL/m² vs. 77 mL/m², P <0.0001). HF patients with atrial fibrillation and/or type 2 diabetes mellitus had more epicardial fat than HF patients without these co‐morbidities (116 vs. 100 mL/m², P =0.03, and 120 vs. 97 mL/m², P =0.001, respectively). Creatine kinase‐MB, troponin T and glycated haemoglobin in patients with HF were positively correlated with epicardial fat volume (R =0.37, P =0.006; R =0.35, P =0.01; and R =0.42, P =0.002, respectively).

Conclusion

Heart failure patients had more epicardial fat compared to controls, despite similar body mass index. Epicardial fat volume was associated with the presence of atrial fibrillation and type 2 diabetes mellitus and with biomarkers related to myocardial injury. The clinical implications of these findings are unclear, but warrant further investigation.

Obesity, ectopic fat and cardiac metabolism

INTRODUCTION

Obesity is recognized as a risk factor for cardiovascular disease, expending independent adverse effects on the cardiovascular system. This relationship is complex due to several associations with cardiovascular disease risk factors/markers such as hypertension, dyslipidemia, insulin resistance/dysglycemia, or type 2 diabetes mellitus. Obesity induces a variety of cardiovascular system structural adaptations, from subclinical myocardial dysfunction to severe left ventricular systolic heart failure. Abnormalities in cardiac metabolism and subsequent cardiac energy, have been proposed as major contributors to obesity-related cardiovascular disease. Ectopic fat depots play an important role in several of the hypotheses postulated to explain the association between obesity, cardiac metabolism and cardiac dysfunction.

AREAS COVERED

In this review, we addressed with contemporary studies how obesity-associated metabolic conditions and ectopic cardiac fat accumulation, translate into cardiac energy metabolism disturbances that may lead to adverse effects on the cardiovascular system.

EXPERT COMMENTARY

Obesity and ectopic fat accumulation has long been related to metabolic diseases and adverse cardiovascular outcomes. Recent imaging advances have just started to address the complex interplays between obesity, ectopic fat depots, cardiac metabolism and the risk of obesity-related cardiovascular disease. A better comprehension of these obesity-associated metabolic disturbances will lead to earlier detection of patients at increased risk of cardiovascular disease and to the development of novel therapeutic metabolic targets to treat a wide variety of cardiovascular diseases.

Type 2 diabetes: Does pancreatic fat really matter?

With the increasing prevalence of obesity, the interest of research in nonalcoholic fatty pancreas disease (NAFPD) has grown. Even though the pancreas appears more susceptible to lipid accumulation compared with the liver, NAFPD has been less investigated due to the limits in detecting techniques. Several definitions and synonyms for NAFPD are used by authors and can be misleading. This, together with differences in methodology and ethnicity, make the integration and comparison of studies on this topic challenging. NAFPD could be used as an early indicator of ectopic fat deposition, which is recognized as a key factor of obesity cardio-metabolic complications. However, evidence that NAFPD has a pathogenetic role in type 2 diabetes is also emerging. This article reviews the current state of knowledge on the clinical and pathophysiologic relevance of NAFPD in β-cell function and insulin resistance.

Obesity phenotypes: depot-differences in adipose tissue and their clinical implications

Obesity, defined as excess fat mass, increases risks for multiple chronic diseases, such as type 2 diabetes, cardiovascular disease, and several types of cancer. Beyond adiposity per se, the pattern of fat distribution, android or truncal as compared to gynoid or peripheral, has a profound influence on systemic metabolism and hence risk for obesity complications. Not only factors as genetics, environment, gender, and age account for the apparent compartmentalization of white adipose tissue (WAT) in the body. Indeed, the heterogeneity among different anatomical depots also appears to stem from their intrinsic diversity, including cellular developmental origin, proliferative capacity, glucose and lipid metabolism, insulin sensitivity, cytokine pattern, thermogenic ability, and vascularization. Under the obese condition, these depot-specific differences translate into specific WAT distribution patterns, giving rise to different cardiometabolic consequences. This review summarizes the clinical and mechanistic evidence for the depot-specific differences and the phenotypic characteristics of different WAT depots that link their depot-specific biology to obesity-specific complications.