Activin A is associated with impaired myocardial glucose metabolism and left ventricular remodeling in patients with uncomplicated type 2 diabetes

Relationship between NT-proBNP, echocardiographic abnormalities and functional status in patients with subclinical siabetic cardiomyopathy

INTRODUCTION

Persons with diabetes are at risk for developing a cardiomyopathy through several pathophysiological mechanisms independent of traditional risk factors for heart failure. Among those with diabetic cardiomyopathy (DbCM), the relationship between natriuretic peptides, cardiac structural abnormalities and functional capacity is largely unknown.

METHODS

In this prespecified subgroup analysis of the Aldose Reductase Inhibition for Stabilization of Exercise Capacity in Heart Failure (ARISE-HF) trial, 685 participants with asymptomatic DbCM underwent baseline echocardiography data, laboratory investigations, and functional assessments. Participants were stratified by N-terminal pro-B type natriuretic peptide (NT-proBNP) quartiles, and correlation with echocardiographic and functional parameters were assessed using Spearman correlation test.

RESULTS

The median NT-proBNP was 71 (Q1, Q3: 33, 135) ng/L. No association was observed between NT-proBNP concentrations and echocardiographic parameters of either diastolic or systolic dysfunction including global longitudinal strain, left ventricular ejection fraction, left ventricular mass index, left atrial volume index, E/E', or right ventricular systolic pressure. In contrast, NT-proBNP was significantly correlated with overall Kansas City Cardiomyopathy Questionnaire score (rho = - 0.10; p = 0.007), the Physical Activity Scale in the Elderly (rho = - 0.12; p = 0.004), duration of cardiopulmonary exercise testing (rho = - 0.28; p < 0.001), peak VO2 (rho = - 0.26; p < 0.001), and ratio of minute ventilation/carbon dioxide production (rho = 0.12; p = 0.002). After adjustment for known confounders, the correlation with Physical Activity Scale in the Elderly and overall Kansas City Cardiomyopathy Questionnaire score was no longer significant.

CONCLUSION

Among patients with subclinical DbCM, elevated NT-proBNP concentrations are associated with worse health status, lower activity levels, and reduced functional capacity, but not with cardiac structural abnormalities. These findings suggest that regardless of cardiac structural abnormalities, biomarker concentrations reflect important deterioration in functional capacity in affected individuals.

TRIAL REGISTRATION

ARISE-HF, NCT04083339 Date Registered August 23, 2019.

Association between metformin treatment and coronary artery inflammation based on pericoronary adipose tissue attenuation in type 2 diabetes mellitus patients

Cardiovascular disease (CVD) is the leading cause of mortality in type 2 diabetes mellitus (T2DM) patients. The role of metformin in reducing cardiovascular events is well-established, but its effect on coronary artery inflammation in T2DM patients is still unclear. In this study, we evaluated 547 T2DM patients who underwent coronary computed tomography angiography (CCTA) at Wuhan Central Hospital. Using propensity score matching, we compared the attenuation of pericoronary adipose tissue (PCAT), an imaging marker of coronary artery inflammation, between patients treated with and without metformin. Multiple linear regression models were used to analyze the influence of metformin on PCAT attenuation. The results of the propensity-matched analysis showed that patients on metformin therapy had significantly lower PCAT attenuation, indicating reduced coronary inflammation. Specifically, the PCAT attenuation in the left anterior descending artery (LAD) and right coronary artery (RCA) was lower in the metformin group compared to the non-metformin group. Metformin use was independently associated with decreased LAD-PCAT attenuation in the multivariate regression analysis. The association of metformin with PCAT attenuation differed significantly in populations analyzed in subgroups of patients with obesity and chronic kidney disease. In conclusion, our study shows a preliminary signal that metformin therapy may be associated with decreased coronary artery inflammation in T2DM patients, as indicated by PCAT attenuation on CCTA. And this correlation may vary depending on the patient population. This initial finding suggests that PCAT attenuation could be potentially used as an imaging biomarker to monitor the anti-inflammatory effects of medication.

Plasma activin A rises with declining kidney function and is independently associated with mortality in patients with chronic kidney disease

Background

Plasma (p-)activin A is elevated in chronic kidney disease-mineral and bone disorder (CKD-MBD). Activin A inhibition ameliorates CKD-MBD complications (vascular calcification and bone disease) in rodent CKD models. We examined whether p-activin A was associated with major adverse cardiovascular events (MACE), all-cause mortality and CKD-MBD complications in CKD patients.

Methods

The study included 916 participants (741 patients and 175 controls) from the prospective Copenhagen CKD cohort. Comparisons of p-activin A with estimated glomerular filtration rate (eGFR), coronary and thoracic aorta Agatston scores, and bone mineral density (BMD) were evaluated by univariable linear regression using Spearman's rank correlation, analysis of covariance and ordinal logistic regression with adjustments. Association of p-activin A with rates of MACE and all-cause mortality was evaluated by the Aalen-Johansen or Kaplan-Meier estimator, with subsequent multiple Cox regression analyses.

Results

P-activin A was increased by CKD stage 3 (124-225 pg/mL, P < .001) and correlated inversely with eGFR (r = -0.53, P < 0.01). P-activin A was associated with all-cause mortality [97 events, hazard ratio 1.55 (95% confidence interval 1.04; 2.32), P < 0.05] after adjusting for age, sex, diabetes mellitus (DM) and eGFR. Median follow-up was 4.36 (interquartile range 3.64-4.75) years. The association with MACE was not significant after eGFR adjustment. Agatston scores and BMD were not associated with p-activin A.

Conclusion

P-activin A increased with declining kidney function and was associated with all-cause mortality independently of age, sex, DM and eGFR. No association with MACE, vascular calcification or BMD was demonstrated.

Diminished vasculogenesis under inflammatory conditions is mediated by Activin A

Severe inflammatory stress often leads to vessel rarefaction and fibrosis, resulting in limited tissue recovery. However, signaling pathways mediating these processes are not completely understood. Patients with ischemic and inflammatory conditions have increased systemic Activin A level, which frequently correlates with the severity of pathology. Yet, Activin A's contribution to disease progression, specifically to vascular homeostasis and remodeling, is not well defined. This study investigated vasculogenesis in an inflammatory environment with an emphasis on Activin A's role. Exposure of endothelial cells (EC) and perivascular cells (adipose stromal cells, ASC) to inflammatory stimuli (represented by blood mononuclear cells from healthy donors activated with lipopolysaccharide, aPBMC) dramatically decreased EC tubulogenesis or caused vessel rarefaction compared to control co-cultures, concurrent with increased Activin A secretion. Both EC and ASC upregulated Inhibin Ba mRNA and Activin A secretion in response to aPBMC or their secretome. We identified TNFα (in EC) and IL-1β (in EC and ASC) as the exclusive inflammatory factors, present in aPBMC secretome, responsible for induction of Activin A. Similar to ASC, brain and placental pericytes upregulated Activin A in response to aPBMC and IL-1β, but not TNFα. Both these cytokines individually diminished EC tubulogenesis. Blocking Activin A with neutralizing IgG mitigated detrimental effects of aPBMC or TNFα/IL-1β on tubulogenesis in vitro and vessel formation in vivo. This study delineates the signaling pathway through which inflammatory cells have a detrimental effect on vessel formation and homeostasis, and highlights the central role of Activin A in this process. Transitory interference with Activin A during early phases of inflammatory or ischemic insult, with neutralizing antibodies or scavengers, may benefit vasculature preservation and overall tissue recovery.

Potential clinical biomarkers and perspectives in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is a serious cardiovascular complication and the leading cause of death in diabetic patients. Patients typically do not experience any symptoms and have normal systolic and diastolic cardiac functions in the early stages of DCM. Because the majority of cardiac tissue has already been destroyed by the time DCM is detected, research must be conducted on biomarkers for early DCM, early diagnosis of DCM patients, and early symptomatic management to minimize mortality rates among DCM patients. Most of the existing implemented clinical markers are not very specific for DCM, especially in the early stages of DCM. Recent studies have shown that a number of new novel markers, such as galactin-3 (Gal-3), adiponectin (APN), and irisin, have significant changes in the clinical course of the various stages of DCM, suggesting that we may have a positive effect on the identification of DCM. As a summary of the current state of knowledge regarding DCM biomarkers, this review aims to inspire new ideas for identifying clinical markers and related pathophysiologic mechanisms that could be used in the early diagnosis and treatment of DCM.

Emerging Therapy for Diabetic Cardiomyopathy: From Molecular Mechanism to Clinical Practice

Diabetic cardiomyopathy is characterized by abnormal myocardial structure or performance in the absence of coronary artery disease or significant valvular heart disease in patients with diabetes mellitus. The spectrum of diabetic cardiomyopathy ranges from subtle myocardial changes to myocardial fibrosis and diastolic function and finally to symptomatic heart failure. Except for sodium–glucose transport protein 2 inhibitors and possibly bariatric and metabolic surgery, there is currently no specific treatment for this distinct disease entity in patients with diabetes. The molecular mechanism of diabetic cardiomyopathy includes impaired nutrient-sensing signaling, dysregulated autophagy, impaired mitochondrial energetics, altered fuel utilization, oxidative stress and lipid peroxidation, advanced glycation end-products, inflammation, impaired calcium homeostasis, abnormal endothelial function and nitric oxide production, aberrant epidermal growth factor receptor signaling, the activation of the renin–angiotensin–aldosterone system and sympathetic hyperactivity, and extracellular matrix accumulation and fibrosis. Here, we summarize several important emerging treatments for diabetic cardiomyopathy targeting specific molecular mechanisms, with evidence from preclinical studies and clinical trials.

Effects of treatment of non-alcoholic fatty liver disease on heart failure with preserved ejection fraction

In the past few decades, non-alcoholic fatty liver disease (NAFLD) and heart failure with preserved ejection fraction (HFpEF) have become the most common chronic liver disease and the main form of heart failure (HF), respectively. NAFLD is closely associated with HFpEF by sharing common risk factors and/or by boosting systemic inflammation, releasing other secretory factors, and having an expansion of epicardial adipose tissue (EAT). Therefore, the treatments of NAFLD may also affect the development and prognosis of HFpEF. However, no specific drugs for NAFLD have been approved by the Food and Drug Administration (FDA) and some non-specific treatments for NAFLD are applied in the clinic. Currently, the treatments of NAFLD can be divided into non-pharmacological and pharmacological treatments. Non-pharmacological treatments mainly include dietary intervention, weight loss by exercise, caloric restriction, and bariatric surgery. Pharmacological treatments mainly include administering statins, thiazolidinediones, glucagon-like peptide-1 receptor agonists, sodium-glucose cotransporter 2 inhibitors, and metformin. This review will mainly focus on analyzing how these treatments may affect the development and prognosis of HFpEF.

Sotatercept analog improves cardiopulmonary remodeling and pulmonary hypertension in experimental left heart failure

Pulmonary hypertension due to left heart disease (PH-LHD) is the most frequent manifestation of PH but lacks any approved treatment. Activin receptor type IIA-Fc fusion protein (ActRIIA-Fc) was found previously to be efficacious in experimental and human pulmonary arterial hypertension (PAH). Here we tested the hypothesis that ActRIIA-Fc improves pulmonary vascular remodeling and alleviates PH in models of PH-LHD, specifically in subtypes of heart failure with reduced ejection fraction (PH-HFrEF) and preserved ejection fraction (PH-HFpEF). Treatment with murine ActRIIA-Fc reduced cardiac remodeling and improved cardiac function in two mouse models of left heart disease without PH, confirming that this inhibitor of activin-class ligand signaling can exert cardioprotective effects in heart failure. In a mouse model of PH-HFrEF with prolonged pressure overload caused by transverse aortic constriction, ActRIIA-Fc treatment significantly reduced pulmonary vascular remodeling, pulmonary fibrosis, and pulmonary hypertension while exerting beneficial structural, functional, and histological effects on both the left and right heart. Additionally, in an obese ZSF1-SU5416 rat model of PH-HFpEF with metabolic dysregulation, therapeutic treatment with ActRIIA-Fc normalized SMAD3 overactivation in pulmonary vascular and perivascular cells, reversed pathologic pulmonary vascular and cardiac remodeling, improved pulmonary and cardiac fibrosis, alleviated PH, and produced marked functional improvements in both cardiac ventricles. Studies in vitro revealed that treatment with ActRIIA-Fc prevents an abnormal, glucose-induced, activin-mediated, migratory phenotype in human pulmonary artery smooth muscle cells, providing a mechanism by which ActRIIA-Fc could exert therapeutic effects in experimental PH-HFpEF with metabolic dysregulation. Our results demonstrate that ActRIIA-Fc broadly corrects cardiopulmonary structure and function in experimental PH-LHD, including models of PH-HFrEF and PH-HFpEF, leading to alleviation of PH under diverse pathophysiological conditions. These findings highlight the important pathogenic contributions of activin-class ligands in multiple forms of experimental PH and support ongoing clinical evaluation of human ActRIIA-Fc (sotatercept) in patients with PH-HFpEF.

Impact of Dysfunctional Adipose Tissue Depots on the Cardiovascular System

Obesity with its associated complications represents a social, economic and health problem of utmost importance worldwide. Specifically, obese patients carry a significantly higher risk of developing cardiovascular disease compared to nonobese individuals. Multiple molecular mechanisms contribute to the impaired biological activity of the distinct adipose tissue depots in obesity, including secretion of proinflammatory mediators and reactive oxygen species, ultimately leading to an unfavorable impact on the cardiovascular system. This review summarizes data relating to the contribution of the main adipose tissue depots, including both remote (i.e., intra-abdominal, hepatic, skeletal, pancreatic, renal, and mesenteric adipose fat), and cardiac (i.e., the epicardial fat) adipose locations, on the cardiovascular system. Finally, we discuss both pharmacological and non-pharmacological strategies aimed at reducing cardiovascular risk through acting on adipose tissues, with particular attention to the epicardial fat.

Serum levels of Activin A: Marker of insulin resistance and cardiovascular risk in prediabetics

Background

A substantial proportion of health burden in diabetic individuals can be attributed to cardiovascular complications. The increasing risk of cardiovascular complications along the spectrum of dysglycemia warrants the need to devise novel markers for early assessment and management. Activin A is a multifunctional cytokine with an important role in glucose homeostasis and vascular diseases. It can thus serve as a guide for early identification of cardiovascular disease (CVD) risk in prediabetes.

Objective

The aim of the study was to measure serum levels of activin A in prediabetics, compare them with normoglycemic controls and find the correlation of activin A with markers of insulin resistance such as the homeostatic model assessment of insulin resistance (HOMA-IR).

Methods

Sixty prediabetic patients and similar age-, sex-, blood pressure-, and BMI-matched controls were recruited in the study. In both groups, serum levels of fasting blood glucose and post prandial glucose, glycated hemoglobin (HbA1c) and fasting insulin were measured. HOMA-IR values were calculated. Serum activin A levels were measured in both groups using ELISA. The obtained values were compared between the two groups.

Results

The median (IQR) of s. fasting insulin (mIU/L) in the case group was 15.3 (12.2-18.62) which was significantly higher than that in the control group, which was 6 (4.2-7.3). The median (IQR) of s. activin A (ng/mL) in the case group was 263.55 (227.18-279.56) which was significantly higher than that in the control group, which was 159.9 (150.73-178.75) (P < 0.001). There was a very strong positive correlation of s. activin A (ng/mL) with s. fasting insulin (mIU/L) and HOMA-IR (rho = 0.67 and 0.75, respectively, P < 0.001).

Conclusion

Activin A, if combined with other atherosclerotic markers, might improve the assessment of insulin resistance and cardiovascular risk in prediabetics and lead to focus on lifestyle modifications and preventive medical therapy, thereby contributing to the prevention of CVD-related mortality and morbidity in these patients.

Epicardial Adipose Tissue and Cardiac Arrhythmias: Focus on Atrial Fibrillation

Atrial Fibrillation (AF) is the most frequent cardiac arrhythmia and its prevalence increases with age. AF is strongly associated with an increased risk of stroke, heart failure and cardiovascular mortality. Among the risk factors associated with AF onset and severity, obesity and inflammation play a prominent role. Numerous recent evidence suggested a role of epicardial adipose tissue (EAT), the visceral fat depot of the heart, in the development of AF. Several potential arrhythmogenic mechanisms have been attributed to EAT, including myocardial inflammation, fibrosis, oxidative stress, and fat infiltration. EAT is a local source of inflammatory mediators which potentially contribute to atrial collagen deposition and fibrosis, the anatomical substrate for AF. Moreover, the close proximity between EAT and myocardium allows the EAT to penetrate and generate atrial myocardium fat infiltrates that can alter atrial electrophysiological properties. These observations support the hypothesis of a strong implication of EAT in structural and electrical atrial remodeling, which underlies AF onset and burden. The measure of EAT, through different imaging methods, such as echocardiography, computed tomography and cardiac magnetic resonance, has been proposed as a useful prognostic tool to predict the presence, severity and recurrence of AF. Furthermore, EAT is increasingly emerging as a promising potential therapeutic target. This review aims to summarize the recent evidence exploring the potential role of EAT in the pathogenesis of AF, the main mechanisms by which EAT can promote structural and electrical atrial remodeling and the potential therapeutic strategies targeting the cardiac visceral fat.

Role of Epicardial Adipose Tissue in Cardiovascular Diseases: A Review

Simple Summary

Cardiovascular diseases (CVDs) are the leading causes of death worldwide. Epicardial adipose tissue (EAT) is one of the most important risk factors for cardiovascular events and a promising new therapeutic target in CVDs. Here, we summarize the currently available evidence regarding the role of EAT in the development of CVDs, including coronary artery disease, heart failure and atrial fibrillation; compile data regarding the association between EAT’s function and the course of COVID-19; and present new potential therapeutic possibilities, aiming at modifying EAT’s function. The development of novel therapies specifically targeting EAT could revolutionize the prognosis in CVDs.

Abstract

Cardiovascular diseases (CVDs) are the leading causes of death worldwide. Epicardial adipose tissue (EAT) is defined as a fat depot localized between the myocardial surface and the visceral layer of the pericardium and is a type of visceral fat. EAT is one of the most important risk factors for atherosclerosis and cardiovascular events and a promising new therapeutic target in CVDs. In health conditions, EAT has a protective function, including protection against hypothermia or mechanical stress, providing myocardial energy supply from free fatty acid and release of adiponectin. In patients with obesity, metabolic syndrome, or diabetes mellitus, EAT becomes a deleterious tissue promoting the development of CVDs. Previously, we showed an adverse modulation of gene expression in pericoronary adipose tissue in patients with coronary artery disease (CAD). Here, we summarize the currently available evidence regarding the role of EAT in the development of CVDs, including CAD, heart failure, and atrial fibrillation. Due to the rapid development of the COVID-19 pandemic, we also discuss data regarding the association between EAT and the course of COVID-19. Finally, we present the potential therapeutic possibilities aiming at modifying EAT’s function. The development of novel therapies specifically targeting EAT could revolutionize the prognosis in CVDs.

HMEJ-mediated site-specific integration of a myostatin inhibitor increases skeletal muscle mass in porcine

As a robust antagonist of myostatin (MSTN), follistatin (FST) is an important regulator of skeletal muscle development, and the delivery of FST to muscle tissue represents a potential therapeutic strategy for muscular dystrophies. The N terminus and FSI domain of FST are the functional domains for MSTN binding. Here, we aimed to achieve site-specific integration of FSI-I-I, including the signal peptide, N terminus, and three FSI domains, into the last codon of the porcine MSTN gene using a homology-mediated end joining (HMEJ)-based strategy mediated by CRISPR-Cas9. Based on somatic cell nuclear transfer (SCNT) technology, we successfully obtained FSI-I-I knockin pigs. H&E staining of longissimus dorsi and gastrocnemius cross-sections showed larger myofiber sizes in FSI-I-I knockin pigs than in controls. Moreover, the Smad and Erk pathways were inhibited, whereas the PI3k/Akt pathway was activated in FSI-I-I knockin pigs. In addition, the levels of MyoD, Myf5, and MyoG transcription were upregulated while that of MRF4 was downregulated in FSI-I-I knockin pigs. These results indicate that the FSI-I-I gene mediates skeletal muscle hypertrophy through an MSTN-related signaling pathway and the expression of myogenic regulatory factors. Overall, FSI-I-I knockin pigs with hypertrophic muscle tissue hold great promise as a therapeutic model for human muscular dystrophies.

Role of novel biomarkers in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is commonly defined as cardiomyopathy in patients with diabetes mellitus in the absence of coronary artery disease and hypertension. As DCM is now recognized as a cause of substantial morbidity and mortality among patients with diabetes mellitus and clinical diagnosis is still inappropriate, various expert groups struggled to identify a suitable biomarker that will help in the recognition and management of DCM, with little success so far. Hence, we thought it important to address the role of biomarkers that have shown potential in either human or animal studies and which could eventually result in mitigating the poor outcomes of DCM. Among the array of biomarkers we thoroughly analyzed, long noncoding ribonucleic acids, soluble form of suppression of tumorigenicity 2 and galectin-3 seem to be most beneficial for DCM detection, as their plasma/serum levels accurately correlate with the early stages of DCM. The combination of relatively inexpensive and accurate speckle tracking echocardiography with some of the highlighted biomarkers may be a promising screening method for newly diagnosed diabetes mellitus type 2 patients. The purpose of the screening test would be to direct affected patients to more specific confirmation tests. This perspective is in concordance with current guidelines that accentuate the importance of an interdisciplinary team-based approach.

Left Atrial Myopathy in Atrial Fibrillation and Heart Failure: Clinical Implications, Mechanisms, and Therapeutic Targets

PURPOSE OF REVIEW

This review discusses the mechanisms, clinical implications, and treatments of left atrial (LA) myopathy in comorbid atrial fibrillation (AF) and heart failure (HF) across the spectrum of ejection fraction.

RECENT FINDINGS

AF and HF are highly comorbid conditions. Left atrial (LA) myopathy, characterized by impairments in LA structure, function, or electrical conduction, plays a fundamental role in the development of both AF and HF with preserved ejection fraction (AF-HFpEF) along with AF and HF with reduced ejection fraction (AF-HFrEF). While the nature of LA myopathy in AF-HFpEF is unique from that of AF-HFrEF, LA myopathy also leads to progression of both of these conditions. There may be a vulnerable cohort of AF-HF patients who have a disproportionate degree of LA myopathy compared with left ventricular (LV) dysfunction. Further investigations are required to identify therapies to improve LA function in this cohort.

Diabetic cardiomyopathy

The relationship between diabetes and heart failure is complex and bidirectional. Nevertheless, the existence of a cardiomyopathy attributable exclusively to diabetes has been and is still the subject of controversy, due, among other reasons, to a lack of a consensus definition. There is also no unanimous agreement in terms of the physiopathogenic findings that need to be present in the definition of diabetic cardiomyopathy or on its classification, which, added to the lack of diagnostic methods and treatments specific for this disease, limits its general understanding. Studies conducted on diabetic cardiomyopathy, however, suggest a unique physiopathogenesis different from that of other diseases. Similarly, new treatments have been shown to play a potential role in this disease. The following review provides an update on diabetic cardiomyopathy.

Exercise as A Potential Therapeutic Target for Diabetic Cardiomyopathy: Insight into the Underlying Mechanisms

Diabetes mellitus is associated with cardiovascular, ophthalmic, and renal comorbidities. Among these, diabetic cardiomyopathy (DCM) causes the most severe symptoms and is considered to be a major health problem worldwide. Exercise is widely known as an effective strategy for the prevention and treatment of many chronic diseases. Importantly, the onset of complications arising due to diabetes can be delayed or even prevented by exercise. Regular exercise is reported to have positive effects on diabetes mellitus and the development of DCM. The protective effects of exercise include prevention of cardiac apoptosis, fibrosis, oxidative stress, and microvascular diseases, as well as improvement in cardiac mitochondrial function and calcium regulation. This review summarizes the recent scientific findings to describe the potential mechanisms by which exercise may prevent DCM and heart failure.

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

Aims

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

Methods and results

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

Conclusions

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

Interplay between epicardial adipose tissue, metabolic and cardiovascular diseases

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

Emerging Actors in Diabetic Cardiomyopathy: Heartbreaker Biomarkers or Therapeutic Targets?

The diabetic heart is characterized by metabolic disturbances that are often accompanied by local inflammation, oxidative stress, myocardial fibrosis, and cardiomyocyte apoptosis. Overall changes result in contractile dysfunction, concentric left ventricular (LV) hypertrophy, and dilated cardiomyopathy, that together affect cardiac output and eventually lead to heart failure, the foremost cause of death in diabetic patients. There are currently several validated biomarkers for the diagnosis and risk assessment of cardiac diseases, but none is capable of discriminating patients with diabetic cardiomyopathy (DCM). In this review we point to several novel candidate biomarkers from new activated molecular pathways (including microRNAs) with the potential to detect or prevent DCM in its early stages, or even to treat it once established. The prospective use of selected biomarkers that integrate inflammation, oxidative stress, fibrosis, and metabolic dysregulation is widely discussed.

Hyperglycemia is associated with reduced testicular function and activin dysregulation in the Ins2Akita+/- mouse model of type 1 diabetes

Type 1 diabetes (T1D) is associated with subfertility in men. We hypothesised that this results from inhibitory effects of chronic hyperglycemia on testicular function and used the Ins2^Akita+/- mouse model to investigate this. Diabetic mice exhibited progressive testicular dysfunction, with a 30% reduction in testis weight at 24 weeks of age. Diabetic mice showed significantly reduced seminiferous tubule diameters and increased spermatogenic disruption, although testes morphology appeared grossly normal. Unexpectedly, serum LH and intra-testicular testosterone were similar in all groups. Ins2^Akita+/- mice displayed elevation of the testicular inflammatory cytokines activin A and IL-6. Intratesticular activin B was downregulated, while the activin regulatory proteins, follistatin and inhibin, were unchanged. Activin signalling, measured by pSmad3 and Smad4 production, was enhanced in diabetic mice only. These results suggest that prolonged exposure to hyperglycemia in the Ins2^Akita+/- mice leads to progressive testicular disruption mediated by testicular activin activity, rather than hormonal dysregulation.

Diagnostic approaches for diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is a cardiac dysfunction which affects approximately 12% of diabetic patients, leading to overt heart failure and death. However, there is not an efficient and specific methodology for DCM diagnosis, possibly because molecular mechanisms are not fully elucidated, and it remains asymptomatic for many years. Also, DCM frequently coexists with other comorbidities such as hypertension, obesity, dyslipidemia, and vasculopathies. Thus, human DCM is not specifically identified after heart failure is established. In this sense, echocardiography has been traditionally considered the gold standard imaging test to evaluate the presence of cardiac dysfunction, although other techniques may cover earlier DCM detection by quantification of altered myocardial metabolism and strain. In this sense, Phase-Magnetic Resonance Imaging and 2D/3D-Speckle Tracking Echocardiography may potentially diagnose and stratify diabetic patients. Additionally, this information could be completed with a quantification of specific plasma biomarkers related to related to initial stages of the disease. Cardiotrophin-1, activin A, insulin-like growth factor binding protein-7 (IGFBP-7) and Heart fatty-acid binding protein have demonstrated a stable positive correlation with cardiac hypertrophy, contractibility and steatosis responses. Thus, we suggest a combination of minimally-invasive diagnosis tools for human DCM recognition based on imaging techniques and measurements of related plasma biomarkers.

Activin A Predicts Left Ventricular Remodeling and Mortality in Patients with ST-Elevation Myocardial Infarction

BACKGROUND

Activin A levels increase in a variety of heart diseases including ST-elevation myocardial infarction (STEMI). The aim of this study is to investigate whether the level of activin A can be beneficial in predicting left ventricular remodeling, heart failure, and death in patients with ST-elevation myocardial infarction (STEMI).

METHODS

We enrolled 278 patients with STEMI who had their activin A levels measured on day 2 of hospitalization. Echocardiographic studies were performed at baseline and were repeated 6 months later. Thereafter, the clinical events of these patients were followed for a maximum of 3 years, including all-cause death and readmission for heart failure.

RESULTS

During hospitalization, higher activin A level was associated with higher triglyceride level, lower left ventricular ejection fraction (LVEF), and lower left ventricular end diastolic ventricular volume index (LVEDVI) in multivariable linear regression model. During follow-up, patients with activin A levels > 129 pg/ml had significantly lower LVEF, and higher LVEDVI at 6 months. Kaplan-Meier survival curves showed that activin A level > 129 pg/ml was a predictor of all-cause death (p = 0.022), but not a predictor of heart failure (p = 0.767).

CONCLUSIONS

Activin A level > 129 pg/ml predicts worse left ventricular remodeling and all-cause death in STEMI.

Visceral adiposity is associated with altered myocardial glucose uptake measured by (18)FDG-PET in 346 subjects with normal glucose tolerance, prediabetes, and type 2 diabetes

Background

The heart requires constant sources of energy mostly from free fatty acids (FFA) and glucose. The alteration in myocardial substrate metabolism occurs in the heart of diabetic patients, but its specific association with other metabolic variables remains unclear. We aimed to evaluate glucose uptake in hearts of subjects with normal glucose tolerance (NGT), prediabetes, and type 2 diabetes mellitus (T2DM) using [¹⁸F]-fluorodeoxyglucose-positron emission tomography (¹⁸FDG-PET) in association with visceral and subcutaneous adiposity, and metabolic laboratory parameters.

Methods

A total of 346 individuals (NGT, n = 76; prediabetes, n = 208; T2DM, n = 62) in a health promotion center of a tertiary hospital were enrolled. The fasting myocardial glucose uptake, and visceral and subcutaneous fat areas were evaluated using ¹⁸FDG-PET and abdominal computed tomography, respectively.

Results

Myocardial glucose uptake was significantly decreased in subjects with T2DM compared to the NGT or prediabetes groups (p for trend = 0.001). Multivariate linear regression analyses revealed that visceral fat area (β = −0.22, p = 0.018), fasting FFA (β = −0.39, p < 0.001), and uric acid levels (β = −0.21, p = 0.007) were independent determinants of myocardial glucose uptake. Multiple logistic analyses demonstrated that decreased myocardial glucose uptake (OR 2.32; 95 % CI 1.02–5.29, p = 0.045) and visceral fat area (OR 1.02, 95 % CI 1.01–1.03, p = 0.018) were associated with T2DM.

Conclusions

Our findings indicate visceral adiposity is strongly associated with the alteration of myocardial glucose uptake evaluated by ¹⁸FDG-PET, and its association further relates to T2DM.