Diastolic dysfunction in diabetes and the metabolic syndrome: promising potential for diagnosis and prognosis

T2D-LVDD: neural network-based predictive models for left ventricular diastolic dysfunction in type 2 diabetes

Cardiovascular disease complications are the leading cause of morbidity and mortality in patients with Type 2 diabetes (T2DM). Left ventricular diastolic dysfunction (LVDD) is one of the earliest myocardial characteristics of diabetic cardiac dysfunction. Therefore, we aimed to develop an LVDD-risk predictive model to diagnose cardiac dysfunction before severe cardiovascular complications arise. We trained an artificial neural network model to predict LVDD risk with patients' clinical information. The model showed better performance than classical machine learning methods such as logistic regression, random forest and support vector machine. We further explored LVDD-risk/protective features with interpretability methods in neural network. Finally, we provided a freely accessible web server called LVDD-risk, where users can submit their clinical information to obtain their LVDD-risk probability and the most noteworthy risk indicators.

Emirates consensus recommendations on cardiovascular risk management in type 2 diabetes

Background

The combination of cardiovascular disease and diabetes is a highly prevalent condition in the United Arab Emirates. Development and dissemination of evidence-based regional recommendations for optimal screening, treatment and referrals of people with diabetes and high cardiovascular risk is an important priority.

Consensus panel

An expert panel of diabetologists, endocrinologists and cardiologists from the Emirates Cardiac Society and Emirates Diabetes and Endocrine Society as well as different entities in the UAE, discussed and reviewed evidence and also a consensus report from the American Diabetes Association to formulate contextualized recommendations that could be applied for optimal management of cardiovascular risk in people with diabetes in the UAE.

Consensus findings

The combination of heart failure and other cardiovascular risks is a highly prevalent finding among people with diabetes in the United Arab Emirates. The causal inter-relationships between diabetes and heart failure are multifactorial and regular assessments of symptoms and steps for mitigation of risk factors are an important priority. The universal definition and classification of heart failure provides a useful framework for recommending optimal screening, treatment, and referral strategies to diabetic individuals at various stages of the cardiovascular continuum. Routine measurement (at least yearly) of natriuretic peptides and high-sensitivity troponins can help identify patients requiring cardiac imaging referrals. However, recommending routine measurements of natriuretic peptides and/or high-sensitivity troponins to all diabetic individuals must balance clinical judgment and cost implications. While SGLT2i must be an important part of the standard of care, insulin, GLP1 receptor agonists and/or metformin can be useful for additional glycemic control.

Conclusion

The consensus panel hopes that the recommendations presented herein can offer guidance for optimal screening, treatment and referral of people with a concomitance of diabetes and high cardiovascular risk in the United Arab Emirates.

Metformin Regulates Cardiac Ferroptosis to Reduce Metabolic Syndrome-Induced Cardiac Dysfunction

High-fat diet-induced metabolic syndrome (MetS) is closely associated with cardiac dysfunction. Recent research studies have indicated a potential association between MetS and ferroptosis. Furthermore, metformin can alleviate MetS-induced cardiac ferroptosis. Metformin is a classic biguanide anti-diabetic drug that has protective effects on cardiovascular diseases, which extend beyond its indirect glycemic control. This study aimed to assess whether MetS mediates cardiac ferroptosis, thereby causing oxidative stress and mitochondrial dysfunction. The results revealed that metformin can mitigate cardiac reactive oxygen species and mitochondrial damage, thereby preserving cardiac function. Mechanistic analysis revealed that metformin upregulates the expression of cardiac Nrf2. Moreover, Nrf2 downregulation compromises the cardio-protective effects of metformin. In summary, this study indicated that MetS promotes cardiac ferroptosis, and metformin plays a preventive and therapeutic role, partially through modulation of Nrf2 expression.

Embryonic alcohol exposure in zebrafish predisposes adults to cardiomyopathy and diastolic dysfunction

AIMS

Fetal alcohol spectrum disorders (FASDs) impact up to 0.8% of the global population. However, cardiovascular health outcomes in adult patients, along with predictive biomarkers for cardiac risk stratification, remain unknown. Our aim was to utilize a longitudinal cohort study in an animal model to evaluate the impact of embryonic alcohol exposure (EAE) on cardiac structure, function, and transcriptional profile across the lifespan.

METHODS AND RESULTS

Using zebrafish, we characterized the aftereffects of EAE in adults binned by congenital heart defect (CHD) severity. Chamber sizes were quantified on dissected adult hearts to identify structural changes indicative of cardiomyopathy. Using echocardiography, we quantified systolic function based on ejection fraction and longitudinal strain, and diastolic function based on ventricular filling dynamics, ventricular wall movement, and estimated atrial pressures. Finally, we performed RNA-sequencing on EAE ventricles and assessed how differentially expressed genes (DEGs) correlated with cardiac function. Here, we demonstrate that EAE causes cardiomyopathy and diastolic dysfunction through persistent alterations to ventricular wall structure and gene expression. Following abnormal ventricular morphogenesis, >30% of all EAE adults developed increased atrial-to-ventricular size ratios, abnormal ventricular filling dynamics, and reduced myocardial wall relaxation during early diastole despite preserved systolic function. RNA-sequencing of the EAE ventricle revealed novel and heart failure-associated genes (slc25a33, ankrd9, dusp2, dusp4, spry4, eya4, and edn1) whose expression levels were altered across the animal's lifespan or correlated with the degree of diastolic dysfunction detected in adulthood.

CONCLUSION

Our study identifies EAE as a risk factor for adult-onset cardiomyopathy and diastolic dysfunction, regardless of CHD status, and suggests novel molecular indicators of adult EAE-induced heart disease.

Interdependence between myocardial deformation and perfusion in patients with T2DM and HFpEF: a feature-tracking and stress perfusion CMR study

BACKGROUND

Patients with diabetes have an increased risk of developing heart failure with preserved ejection fraction (HFpEF). This study aimed to compare indices of myocardial deformation and perfusion between patients with type 2 diabetes mellitus (T2DM) with and without HFpEF and to investigate the relationship between myocardial strain and perfusion reserve.

METHODS

This study included 156 patients with T2DM without obstructive coronary artery disease (CAD) and 50 healthy volunteers who underwent cardiac magnetic resonance (CMR) examination at our center. Patients with T2DM were subdivided into the T2DM-HFpEF (n = 74) and the T2DM-non-HFpEF (n = 82) groups. The parameters of left ventricular (LV) and left atrial (LA) strain as well as stress myocardial perfusion were compared. The correlation between myocardial deformation and perfusion parameters was also assessed. Mediation analyses were used to evaluate the direct and indirect effects of T2DM on LA strain.

RESULTS

Patients with T2DM and HFpEF had reduced LV radial peak systolic strain rate (PSSR), LV circumferential peak diastolic strain rate (PDSR), LA reservoir strain, global myocardial perfusion reserve index (MPRI), and increased LA booster strain compared to patients with T2DM without HFpEF (all P < 0.05). Furthermore, LV longitudinal PSSR, LA reservoir, and LA conduit strain were notably impaired in patients with T2DM without HFpEF compared to controls (all P < 0.05), but LV torsion, LV radial PSSR, and LA booster strain compensated for these alterations (all P < 0.05). Multivariate linear regression analysis demonstrated that LA reservoir and LA booster strain were independently associated with global MPRI (β = 0.259, P < 0.001; β =  - 0.326, P < 0.001, respectively). Further, the difference in LA reservoir and LA booster strain between patients with T2DM with and without HFpEF was totally mediated by global MPRI. Global stress PI, LA booster, global rest PI, and global MPRI showed high accuracy in diagnosing HFpEF among patients with T2DM (areas under the curve [AUC]: 0.803, 0.790, 0.740, 0.740, respectively).

CONCLUSIONS

Patients with T2DM and HFpEF exhibited significant LV systolic and diastolic deformation, decreased LA reservoir strain, severe impairment of myocardial perfusion, and elevated LA booster strain that is a compensatory response in HFpEF. Global MPRI was identified as an independent influencing factor on LA reservoir and LA booster strain. The difference in LA reservoir and LA booster strain between patients with T2DM with and without HFpEF was totally mediated by global MPRI, suggesting a possible mechanistic link between microcirculation impairment and cardiac dysfunction in diabetes. Myocardial perfusion and LA strain may prove valuable for diagnosing and managing HFpEF in the future.

Fetal Strain and Strain Rate Measured with Speckle Tracking Echocardiography in Maternal Diabetes: Systematic Review

INTRODUCTION

The aim of this systematic review and meta-analysis was to evaluate fetal cardiac function in fetuses of mothers with diabetes compared to those of mothers without diabetes using 2D-STE.

METHODS

Embase, MEDLINE, and CENTRAL were searched for observational studies on 2D-STE fetal left and right ventricular global longitudinal strain and strain rate that included singleton, non-anomalous pregnancies complicated by pregestational or gestational diabetes mellitus compared to uncomplicated pregnancies. The strain values were pooled per 4 weeks of gestation for meta-analysis using random-effects models.

RESULTS

Fifteen studies met the criteria, including 990 fetuses of diabetic mothers and 1,645 control fetuses. The study design was cross-sectional in fourteen studies and longitudinal in one study. Gestational age, type of diabetes, ultrasound device, and 2D-STE software varied between the studies. Glycemic control and type of treatment were often lacking. In fetuses of diabetic mothers versus healthy mothers, left ventricular strain was significantly decreased (7 studies), increased (1 study), or not significantly different (7 studies). Right ventricular strain was decreased (7 studies), increased (1 study), or not different (2 studies). Left ventricular strain rate was decreased (3 studies), increased (1 study), or not different (2 studies). Right ventricular strain rate was increased (1 study) or not different (2 studies).

CONCLUSION

Fetuses of mothers with diabetes show evidence of systolic dysfunction, which is more visible in the right ventricle. Contradictory results are probably due to suboptimal study designs and variation in gestational age, diabetes severity, image acquisition, and software. Large prospective longitudinal studies are needed to assess fetal myocardial function with 2D-STE in pregestational diabetes mellitus type 1 and 2 and gestational diabetes mellitus pregnancies. The influence of glycemic control, BMI, and treatment should be evaluated.

Methanolic Extract of Phoenix Dactylifera Confers Protection against Experimental Diabetic Cardiomyopathy through Modulation of Glucolipid Metabolism and Cardiac Remodeling

The incidence of cardiovascular disorders is continuously rising, and there are no effective drugs to treat diabetes-associated heart failure. Thus, there is an urgent need to explore alternate approaches, including natural plant extracts, which have been successfully exploited for therapeutic purposes. The current study aimed to explore the cardioprotective potential of Phoenix dactylifera (PD) extract in experimental diabetic cardiomyopathy (DCM). Following in vitro phytochemical analyses, Wistar albino rats (N = 16, male; age 2-3 weeks) were fed with a high-fat or standard diet prior to injection of streptozotocin (35 mg/kg i.p.) after 2 months and separation into the following four treatment groups: healthy control, DCM control, DCM metformin (200 mg/kg/day, as the reference control), and DCM PD treatment (5 mg/kg/day). After 25 days, glucolipid and myocardial blood and serum markers were assessed along with histopathology and gene expression of both heart and pancreatic tissues. The PD treatment improved glucolipid balance (FBG 110 ± 5.5 mg/dL; insulin 17 ± 3.4 ng/mL; total cholesterol 75 ± 8.5 mg/dL) and oxidative stress (TOS 50 ± 7.8 H2O2equiv./L) in the DCM rats, which was associated with preserved structural integrity of both the pancreas and heart compared to the DCM control (FBG 301 ± 10 mg/dL; insulin 27 ± 3.4 ng/mL; total cholesterol 126 ± 10 mg/dL; TOS 165 ± 12 H2O2equiv./L). Gene expression analyses revealed that PD treatment upregulated the expression of insulin signaling genes in pancreatic tissue (INS-I 1.69 ± 0.02; INS-II 1.3 ± 0.02) and downregulated profibrotic gene expression in ventricular tissue (TGF-β 1.49 ± 0.04) compared to the DCM control (INS-I 0.6 ± 0.02; INS-II 0.49 ± 0.03; TGF-β 5.7 ± 0.34). Taken together, these data indicate that Phoenix dactylifera may offer cardioprotection in DCM by regulating glucolipid balance and metabolic signaling.

Correlations of Serum Lipid Parameters and Atherogenic Indices With Left Ventricular Diastolic Dysfunction Among Apparently Healthy Patients With Type 2 Diabetes Mellitus: A Multicenter In-Hospital Cross-Sectional Study

Background: In adolescents with Type 1 diabetes, lipid ratios are predictors of left ventricular diastolic dysfunction (LVDD). However, whether this also applies to adults with Type 2 Diabetes Mellitus (T2DM) is unclear. This study is aimed at assessing the correlations of serum lipid parameters and atherogenic indices with LVDD in patients with T2DM. Methods: This cross-sectional study included 203 patients with T2DM aged 59.9 ± 13.6 years (111 males, sex ratio: 1 : 2 in favor of males) from eight randomly selected urban hospitals. Demographic information was collected, an anthropometric assessment was performed, and blood pressure was measured. Fasting blood samples were obtained to assess total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TGs), glucose, and glycated hemoglobin. The atherogenic index of plasma (AIP), Castelli Risk Index I (CRI-I), Castelli Risk Index II (CRI-II), atherogenic coefficient, and non-HDL-C were determined using specific formulas. Diastolic function was assessed using echocardiography as per the 2016 updated guidelines of the American Society of Echocardiography (ASE) and the European Association of Cardiovascular Imaging (EACVI). Results: Approximately 47.8% of the participants had LVDD. Compared with participants with normal diastolic function, those with LVDD were more likely to be older than 55 years (p < 0.001), tended to have obesity (p = 0.045), had a higher risk of developing dyslipidemia (p = 0.041), and higher AIP and CRI-II (p < 0.05) levels while having similar low HDL-C and hypertriglyceridemia frequencies. In the multivariate model adjusting for age, high AIP (adjusted odds ratio [aOR], 3.37; 95% confidence interval [CI], 1.22-5.34) and high CRI-II (aOR: 3.80; 95% CI: 2.25-6.35) were independent determinants of LVDD. Conclusions: These results highlight the importance of considering atherogenic indices, primarily AIP and CRI-II in the management of T2DM patients. High AIP and high CRI-II could serve as surrogate markers of LVDD, an early cardiovascular manifestation in patients with T2DM.

Diastolic dysfunction in adults with uncomplicated obesity evaluated with left atrial and left ventricular tissue tracking and ventricular volume-time curve: a prospective cardiac magnetic resonance study

BACKGROUND

Obesity is commonly linked with heart failure (HF) with preserved ejection fraction, with diastolic dysfunction playing an important role in this type of HF. However, diastolic function has not been well clarified in obese patients free of overt comorbidities. We aimed to comprehensively assess diastolic function in adults with uncomplicated obesity by combining left atrial (LA) and left ventricular (LV) strain and ventricular volume-time curve based on cardiac magnetic resonance (CMR), and to evaluate its association with body fat distribution.

METHODS

A cross-sectional study was conducted with 49 uncomplicated obese participants and 43 healthy controls who were continuously recruited in West China Hospital, Sichuan University from September 2019 to June 2022. LA strain indices [total, passive, and active strains (εs, εe, and εa) and peak positive, early negative, and late negative strain rates (SRs, SRe, and SRa)], LV strain rates [peak diastolic strain rate (PDSR) and peak systolic strain rate (PSSR)], and LV volume-time curve parameters [peak filling rate index (PFRI) and peak ejection rate index (PERI)] were measured. Body fat distribution was assessed by dual-energy X-ray absorptiometry. Correlation between body fat distribution and LA and LV function was evaluated by multiple linear regression.

RESULTS

The obese participants had impaired diastolic function, manifested as lower LV circumferential and longitudinal PDSR (1.3±0.2 vs. 1.5±0.3 s-1, P=0.014; 0.8±0.2 vs. 1.1±0.2 s-1, P<0.001), LV PFRI (3.5±0.6 vs. 3.9±0.7 s-1, P=0.012), and declined LA reservoir function [εs and SRs (46.4%±8.4% vs. 51%±12%, P=0.045; 1.9±0.5 vs. 2.3±0.5 s-1, P<0.001)] and conduit function [εe and SRe (30.8%±8.0% vs. 35.5%±9.8%, P=0.019; -3.1±0.8 vs. -3.5±1.0 s-1, P=0.030)] compared with controls. The LA pumping function (εa and SRa) and LV systolic function [LV ejection fraction (LVEF), PSSR and PERI] were not different between obese and control participants. Multivariable analysis indicated that trunk fat had independent relationships with LA εe (β=-0.520, P<0.001) and LV circumferential PDSR (β=-0.418, P=0.003); visceral fat and peripheral fat were associated with LV longitudinal PDSR (β=-0.342, P=0.038; β=0.376, P=0.024); gynoid fat was associated with LA εs (β=0.384, P=0.014) and PFRI (β=0.286, P=0.047) in obesity.

CONCLUSIONS

The obese participants (uncomplicated obese adults with preserved LVEF) had impaired subclinical diastolic function. Central adipose tissue deposits (trunk fat and visceral fat) may exhibit inverse relationships with LV and LA function in obesity. However, peripheral adipose tissue deposits (peripheral fat and gynoid fat) may show positive relationships with LV and LA function.

IL-17 in type II diabetes mellitus (T2DM) immunopathogenesis and complications; molecular approaches

Chronic inflammation has long been considered the characteristic feature of type II diabetes mellitus (T2DM) Immunopathogenesis. Pro-inflammatory cytokines are considered the central drivers of the inflammatory cascade leading to β-cell dysfunction and insulin resistance (IR), two major pathologic events contributing to T2DM. Analyzing the cytokine profile of T2DM patients has also introduced interleukin-17 (IL-17) as an upstream regulator of inflammation, regarding its role in inducing the nuclear factor-kappa B (NF-κB) pathway. In diabetic tissues, IL-17 induces the expression of inflammatory cytokines and chemokines. Hence, IL-17 can deteriorate insulin signaling and β-cell function by activating the JNK pathway and inducing infiltration of neutrophils into pancreatic islets, respectively. Additionally, higher levels of IL-17 expression in patients with diabetic complications compared to non-complicated individuals have also proposed a role for IL-17 in T2DM complications. Here, we highlight the role of IL-17 in the Immunopathogenesis of T2DM and corresponding pathways, recent advances in preclinical and clinical studies targeting IL-17 in T2DM, and corresponding challenges and possible solutions.

Effects of Glucagon-Like Peptide-1 Receptor Agonist (GLP-1RA) on Cardiac Structure and Function: A Systematic Review and Meta-Analysis of Randomized-Controlled Trials

PURPOSE

Recent trials suggest glucagon-like peptide-1 receptor agonists (GLP-1RAs) may have a cardioprotective role by reducing major adverse cardiac events, stroke mortality and heart failure-related hospitalisations. We examined whether and how GLP-1RAs affect cardiac function in cardiovascular and metabolic diseases including type 2 diabetes, heart failure and post-myocardial infarction.

METHODS

In this PRISMA-adherent systematic review and meta-analysis, three databases were searched from inception to July 2021 and registered on PROSPERO (CRD42021259661).

RESULTS

20 reports of 19 randomized placebo-controlled trials including 2062 participants were meta-analyzed. Among type 2 diabetes patients, GLP-1RA resulted in improved systolic function measured by circumferential strain (mean difference [MD]= -5.48; 95% CI: -10.47 to -0.49; P= 0.03; I2= 89%) and diastolic dysfunction measured by E / A (MD= -0.15; 95% CI: -0.25 to -0.05; P= 0.003; I2= 0%). For post-myocardial infarction patients, GLP-1RA reduced infarct size (g) (MD= -5.36; 95% CI: -10.68 to -0.04; P= 0.05; I2= 78%). Liraglutide, but not exenatide, demonstrated improved systolic function, by increasing left ventricular ejection fraction (MD= 4.89; 95% CI: 3.62 to 6.16; P< 0.00001; I2= 0%) and reducing left ventricular end-systolic volume (MD= -4.15; 95% CI: -7.49 to -0.81; P = 0.01; I2= 0%). Among heart failure patients, no significant changes were noted.

CONCLUSION

GLP-1RA drugs may improve systolic and diastolic function in type 2 diabetes and reduce infarct size post-acute myocardial infarction with no demonstrable effect on cardiac function in heart failure. Tailored recommendations for the use of GLP-1RAs for cardioprotection should be considered for each patient's condition.

A genetic mouse model of lean-NAFLD unveils sexual dimorphism in the liver-heart axis

Lean patients with NAFLD may develop cardiac complications independently of pre-existent metabolic disruptions and comorbidities. To address the underlying mechanisms independent of the development of obesity, we used a murine model of hepatic mitochondrial deficiency. The liver-heart axis was studied as these mice develop microvesicular steatosis without obesity. Our results unveil a sex-dependent phenotypic remodeling beyond liver damage. Males, more than females, show fasting hypoglycemia and increased insulin sensitivity. They exhibit diastolic dysfunction, remodeling of the circulating lipoproteins and cardiac lipidome. Conversely, females do not manifest cardiac dysfunction but exhibit cardiometabolic impairments supported by impaired mitochondrial integrity and β-oxidation, remodeling of circulating lipoproteins and intracardiac accumulation of deleterious triglycerides. This study underscores metabolic defects in the liver resulting in significant sex-dependent cardiac abnormalities independent of obesity. This experimental model may prove useful to better understand the sex-related variability, notably in the heart, involved in the progression of lean-NAFLD.

Type 1 Diabetes and Cardiovascular Health

Type 1 diabetes (T1D) is associated with an increased risk of cardiovascular disease (CVD). CVD occurs much earlier in people with T1D than in the general population, and several risk factors have been identified some of which are modifiable. Risk prediction models and imaging tests to detect early signs of CVD have not been extensively validated. Strategies to promote cardiovascular health (CVH) in T1D include identifying risk factors, early treatment to achieve CVH targets, and improving the education of health care providers and people with T1D.

Nrf2 Pathway and Oxidative Stress as a Common Target for Treatment of Diabetes and Its Comorbidities

Diabetes is a chronic disease that induces many comorbidities, including cardiovascular disease, nephropathy, and liver damage. Many mechanisms have been suggested as to how diabetes leads to these comorbidities, of which increased oxidative stress in diabetic patients has been strongly implicated. Limited knowledge of antioxidative antidiabetic drugs and substances that can address diabetic comorbidities through the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway calls for detailed investigation. This review will describe how diabetes increases oxidative stress, the general impact of that oxidative stress, and how oxidative stress primarily contributes to diabetic comorbidities. It will also address how treatments for diabetes, especially focusing on their effects on the Nrf2 antioxidative pathway, have been shown to similarly affect the Nrf2 pathway of the heart, kidney, and liver systems. This review demonstrates that the Nrf2 pathway is a common pathogenic component of diabetes and its associated comorbidities, potentially identifying this pathway as a target to guide future treatments.

Cross-sectional associations between questionnaire-measured physical activity and tissue doppler indices of left ventricular diastolic function

BACKGROUND

The prevalence of left ventricular (LV) diastolic dysfunction has been increasing over the past decade, and to date, effective pharmacotherapies that enhance LV diastolic function have not yet been identified. Though some data has demonstrated the beneficial effects of exercise training on LV diastolic function, little is known about the adaptations of diastolic function to daily physical activity (PA). Accordingly, our study aimed to investigate the impact of daily PA on tissue Doppler indices of LV diastolic function.

METHODS

A total of 432 participants were enrolled for clinically indicated echocardiography from July 2019 to July 2020 at Peking University People's Hospital. Participants aged ≥ 18 years were included if they had stable PA in the past six months and normal LV systolic function. A questionnaire was used to collect demographic characteristics, medical history, and daily PA. According to PA Guidelines for Americans, we identified these participants into low-intensity PA (LPA) group and moderate-high-intensity PA (MHPA) group. Propensity score matching (PSM) was performed to match potential confounding factors between the two groups. The clinical characteristics and echocardiographic parameters between LPA group and MHPA group were compared using student's t-test, Mann-Whitney U test, and chi-square test as appropriate.

RESULTS

After matching potential confounding factors using PSM with a 1:3 matching ratio, our final analysis included 86 cases in the MHPA group and 214 cases in the LPA group. All demographic characteristics and comorbidities were statistically similar between the two groups. Compared to the LPA group, the MHPA group showed higher septal e' (7.9 ± 2.9 cm/s versus 7.2 ± 2.6 cm/s, P = 0.047). Other echocardiographic parameters associated with LV diastolic function concerning lateral e' and average E/e', also trended towards improved LV diastolic function in the MHPA group, but failed to reach statistical significance.

CONCLUSIONS

Our study demonstrated that moderate-high-intensity daily PA was associated with improved septal e', suggesting that moderate-high-intensity PA could potentially ameliorate LV diastolic dysfunction.

Metabolic syndrome - cardiac structure and functional analysis by echocardiography; a cross sectional comparative study

OBJECTIVES

Metabolic syndrome (MS) is a collection of metabolic disorders including hyperglycemia, hypertension and dyslipidemia. The outcome of metabolic syndrome depends on structural changes in heart like increased left atrial size or increased left ventricular mass. This study was done to determine the echocardiography abnormalities in metabolic syndrome.

METHODS

After obtaining informed consent, 75 subjects with metabolic syndrome and 75 controls were included in the study. 2D echo/M mode examination was performed for all. Aortic root, left atrial size, left atrial volume, septal wall thickness during systole (SWs) and diastole (SWd), posterior wall thickness during systole (PWs) and diastole (PWd), left ventricle dimension during systole (LVDs) and diastole (LVDd), and ejection fraction were measured. The values were compared between the groups.

RESULTS

After adjustment for age, sex, smoking, alcohol and BMI; left ventricular diameter in systole and diastole was significantly more than controls (p<0.001); HR of 1.29 (95% CI 1.13-1.46), 1.29 (95% CI 1.15-1.45) respectively. Left ventricular mass and left atrial volume were increased significantly in subjects with metabolic syndrome (p<0.001); HR were 1.06 (95% CI 1.03-1.08), 1.13 (95% CI 1.06-1.19) respectively. Ejection fraction was low normal in subjects with metabolic syndrome compared to controls (p<0.05); HR 0.90 (95% CI 0.83-0.98).

CONCLUSIONS

Cardiac abnormalities were common in subjects with metabolic syndrome, predominantly affecting the left ventricular mass, diameter and left atrial volume. Early life style modifications are essential to prevent these complications.

Diet-Induced Microbiome's Impact on Heart Failure: A Double-Edged Sword

Heart failure (HF) is a debilitating disease with a significant clinical and economic impact worldwide. Multiple factors seem to increase the risk of developing HF, such as hypertension, obesity and diabetes. Since chronic inflammation plays a significant role in HF pathophysiology and gut dysbiosis is associated with low-grade chronic inflammation, the risk of cardiovascular diseases is likely modulated by the gut microbiome (GM). Considerable progress has been made in HF management. However, there is a need to find new strategies to reduce mortality and increase the quality of life, mainly of HFpEF patients, since its prevalence continues to rise. Recent studies validate that lifestyle changes, such as diet modulation, represent a potential therapeutic approach to improve several cardiometabolic diseases, although their effects on the GM and its indirect cardiac impact still warrant further research. Hence, in this paper, we aim to clarify the link between HF and the human microbiome.

Significant Association between Subclinical Left Cardiac Dysfunction and Liver Stiffness in Metabolic Syndrome Patients with Diabetes Mellitus and Non-Alcoholic Fatty Liver Disease

Background and Objectives: Diabetes mellitus (DM) is connected to both cardiovascular disease and non-alcoholic fatty liver disease (NAFLD), and is an important component of metabolic syndrome (MetS). NAFLD can be detected and quantified using the vibration controlled transient elastography (VCTE) and the controlled attenuation parameter (CAP), whereas traditional and two-dimensional speckle tracking echocardiography (2D-STE) can reveal subclinical abnormalities in heart function. We sought to see if there was a link between left cardiac dysfunction and different levels of hepatic fibrosis in MetS patients with DM and NAFLD. Patients and Methods: We recruited successive adult subjects with MetS and a normal left ventricular ejection fraction, who were divided into two groups according to the presence or absence of DM. The presence of NAFLD was established by CAP and VCTE, while conventional and 2D-STE were used to assess left heart's systolic and diastolic function. The mean age of the MetS subjects was 62 ± 10 years, 82 (55%) were men. The distribution of liver steatosis severity was similar among diabetics and non-diabetics, while liver fibrosis grade 2 and 3 was significantly more frequent in diabetics (p = 0.02, respectively p = 0.001). LV diastolic dysfunction was found in 52% of diabetic and in 36% of non-diabetic MetS patients (p = 0.04). 2D-STE identified in the diabetic subjects increased LA stiffness (40% versus 24%, p = 0.03) and reduced global left ventricular longitudinal strain (47% versus 16%, p < 0.0001). Liver fibrosis grade ≥ 2 was identified as an independent predictor of both subclinical LV systolic dysfunction and of LA dysfunction in MetS patients with DM (p < 0.0001). Conclusions: The current investigation confirms the link between liver stiffness and subclinical cardiac dysfunction as detected by 2D-STE in MetS patients with DM. The novel parameters derived from LA and LV 2D-STE have demonstrated greater sensitivity compared to the older measurements, and a substantial connection with hepatic fibrosis.

Impact of glycemic control on biventricular function in patients with type 2 diabetes mellitus: a cardiac magnetic resonance tissue tracking study

BACKGROUND

Poor glycemic control is associated with left ventricular (LV) dysfunction in patients with type 2 diabetes mellitus (T2DM). Nonetheless, the association between glycemic control and right ventricular (RV) function in T2DM has not been studied. This study aimed to evaluate the correlation between glycemic control and biventricular function and assess whether one ventricular function was mediated by the other ventricular changes using cardiac magnetic resonance.

MATERIALS AND METHODS

A total of 91 T2DM patients with normal ejection fraction were enrolled and divided into two groups according to glycated hemoglobin (HbA1c) with a cut off 7%. Twenty controls were included. Biventricular ventricular strain parameters, including global peak systolic radial strain, global peak systolic circumferential strain (GCS), global peak systolic longitudinal strain (GLS), peak diastolic radial strain rate (RSR), peak diastolic circumferential strain rate (CSR) and peak diastolic longitudinal strain rate (LSR) were measured.

RESULTS

Compared with controls, patients with both HbA1c < 7% and HbA1c ≥ 7% showed significantly lower LVGCS, LVGLS, LVCSR, LVLSR, RVGLS, RVRSR, RVCSR and RVLSR. Patients with HbA1c ≥ 7% elicited significantly higher RVGCS than controls and lower LVGLS, LVCSR, LVLSR, RVGLS and RVLSR. Multivariable linear regression demonstrated that HbA1c was independently associated with LVGLS, LVLSR, RVGLS and RVLSR after adjustment for traditional risk factors. LV (RV) was not statistically mediated by the other ventricular alterations.

CONCLUSION

In T2DM patients, glycemic control was independently associated with impaired LV and RV systolic and diastolic function and these associations were not mediated by the other ventricular changes.

Positive feedback loop of miR-320 and CD36 regulates the hyperglycemic memory-induced diabetic diastolic cardiac dysfunction

Intensive glycemic control is insufficient for reducing the risk of heart failure among patients with diabetes mellitus (DM). While the "hyperglycemic memory" phenomenon is well documented, little is known about its underlying mechanisms. In this study, a type 1 DM model was established in C57BL/6 mice using streptozotocin (STZ). Leptin receptor-deficient (db/db) mice were used as a model of type 2 DM. A type 9 adeno-associated virus was used to overexpress or knock down miR-320 in vivo. Diastolic dysfunction was observed in the type 1 DM mice with elevated miR-320 expression. However, glycemic control using insulin failed to reverse diastolic dysfunction. miR-320 knockdown protected against STZ-induced diastolic dysfunction. Similar results were observed in the type 2 DM mice. In vitro, we found that miR-320 promoted CD36 expression, which in turn induced further miR-320 expression. CD36 was rapidly induced by hyperglycemia at protein level compared with the much slower induction of miR-320, suggesting a positive feedback loop of CD36/miR-320 with CD36 protein induction as the initial triggering event. In conclusion, in DM-induced cardiac injury, miR-320 and CD36 mutually enhance each other's expression, leading to a positive feedback loop and a sustained hyperlipidemic state in the heart.

Serum Uric Acid Is Associated with the Progression of Left Ventricular Diastolic Dysfunction in Apparently Healthy Subjects

Background

Left ventricular (LV) diastolic dysfunction (LVDD) is the defining feature of heart failure with preserved ejection fraction (HFpEF) and predicts subsequent incident heart failure (HF) and all-cause mortality. Mounting evidence reveals that cardiometabolic risk factors play critical roles in the development of LVDD. In this study, we sought to investigate the relation between serum uric acid (SUA) level and the progression of LVDD in apparently healthy patients.

Methods

A total of 1082 apparently healthy subjects without diagnosed cardiovascular disease and LVDD were consecutively enrolled. SUA levels were measured, and repeat echocardiography and tissue Doppler imaging (TDI) were performed at baseline and during 1-year follow-up.

Results

By dividing the study population based on quartiles of SUA, we found subjects in higher quartiles had greater increases in TDI-derived early diastolic velocity (e′) and E (peak LV filling velocity)/e′ ratios during 1-year follow-up. After multivariate adjustment, high SUA persisted to be an independent predictor for the subsequent worsening of LVDD (odds ratio: 1.351 [95% CI 1.125~1.625], per 100 μmol/L SUA). Subgroup analysis suggested that the association between SUA and LVDD development was more pronounced in subjects without other cardiometabolic risk factors involved. Factor analysis demonstrated that high SUA was the major cardiometabolic attribute in patients with LVDD progression.

Conclusion

Our findings suggest that high SUA is an independent cardiometabolic risk factor for the progression of LVDD in apparently healthy subjects.

Electrocardiographic and cardiometabolic risk markers of left ventricular diastolic dysfunction in physically active adults: CHIEF heart study

AIM

This study was aimed to investigate the association of cardiometabolic and ECG markers with left ventricular diastolic dysfunction (LVDD) in physically active Asian young adults, which has not been clarified in prior studies.

METHODS AND RESULTS

A total of 2,019 men aged 18-43 years were included from the military in Taiwan. All the subjects underwent anthropometric, hemodynamic, and blood metabolic marker measurements. Physical fitness was investigated by time for a 3,000-m run. LVDD was defined by presence of either one of the three echocardiographic criteria: (1) mitral inflow E/A ratio < 0.8 with a peak E velocity of > 50 cm/s, (2) tissue Doppler lateral mitral annulus e' <10 cm/s, and (3) E/e' ratio > 14. Multiple logistic regressions with adjustments for age, physical fitness, and pulse rate were conducted to determine the association of cardiometabolic and ECG markers with LVDD. The prevalence of LVDD was estimated to be 4.16% (N = 84). Of the cardiometabolic markers, central obesity, defined as waist circumference ≥ 90 cm, was the only independent marker of LVDD [odds ratio (OR) and 95% confidence interval: 2.97 (1.63-5.41)]. There were no association for hypertension, prediabetes, and dyslipidemia. Of the ECG markers, left atrial enlargement and incomplete right bundle branch block/intraventricular conduction delay were the independent ECG markers of LVDD [OR: 2.98 (1.28-6.94) and 1.94 (1.09-3.47), respectively]. There was borderline association for Cornell-based left ventricular hypertrophy and inferior T wave inversion [OR: 1.94 (0.97-3.63) and 2.44 (0.98-6.08), respectively].

CONCLUSION

In the physically active Asian young male adults, central obesity and some ECG markers for left heart abnormalities were useful to identify LVDD.

The Role of Mitochondria in Metabolic Syndrome–Associated Cardiomyopathy

With the rapid development of society, the incidence of metabolic syndrome (MS) is increasing rapidly. Evidence indicated that patients diagnosed with MS usually suffered from cardiomyopathy, called metabolic syndrome–associated cardiomyopathy (MSC). The clinical characteristics of MSC included cardiac hypertrophy and diastolic dysfunction, followed by heart failure. Despite many studies on this topic, the detailed mechanisms are not clear yet. As the center of cellular metabolism, mitochondria are crucial for maintaining heart function, while mitochondria dysfunction plays a vital role through mechanisms such as mitochondrial energy deprivation, calcium disorder, and ROS (reactive oxygen species) imbalance during the development of MSC. Accordingly, in this review, we will summarize the characteristics of MSC and especially focus on the mechanisms related to mitochondria. In addition, we will update new therapeutic strategies in this field.

The Predictive Value of Carotid Artery Strain and Strain-Rate in Assessing the 3-Year Risk for Stroke and Acute Coronary Syndrome in Patients with Metabolic Syndrome

Purpose

The goal of this study is to see if carotid strain and strain rate can predict major cardio-vascular events (MACE) in people who have metabolic syndrome (MS) over a 3-year period of time.

Methods

In this prospective observational research, we enrolled 220 adult MS patients (60.7 ± 7.5 years old, 53% male). Two-dimensional common carotid carotid artery (CCA) speckle-tracking ultrasound was used to determine the peak circumferential strain (CS) and the peak circumferential strain rate (CSR). Clinical outcomes were assessed throughout a three-year follow-up period.

Results

After a 3-year follow-up period follow-up, 14 (7%) experienced MACE: Eight (4%) suffered an atherothrombotic ischemic stroke, four (2%) had acute coronary syndrome, and two (1%) were hospitalized for heart failure. Univariate regression analysis of the clinical and echocardiographic features of the MS patients found that age, systemic hypertension, diabetes mellitus, and the CCA circumferential strain and strain rate were significantly associated with the risk of MACE. Multivariate logistic regression identified two independent predictors of MACE in patients with MS, namely the CCA-related CS (%) and CSR (1/s), p < 0.01. The Receiver operating characteristic (ROC) curve analyses of these independent predictors of MACE indicated appropriate sensitivities and specificities. CS (AUC = 0.806, sensitivity = 82.6%, specificity = 79.2%, p < 0.0001) and CSR (AUC = 0.779, sensitivity = 82.6%, specificity = 72.4%, p < 0.0001) with cut-off values of ≤ 2.9% for carotid CS and ≤ 0.35 s - 1 for carotid CSR. Using these cut-off values, we obtained Kaplan-Meier survival curves, and these showed that MACE, ischemic stroke, and ACS-free survival was significantly lower among the MS patients with lower carotid CS and CSR (p < 0.0001).

Conclusions

Carotid CS and CSR were independent predictors of major cardio- and cerebro-vascular events in prospectively monitored MS patients without established cardiovascular disease. Carotid deformation could be valuable as an early prognostic indicator for the cardiovascular risk in this population group.

Cardiac remodeling and subclinical left ventricular dysfunction in adults with uncomplicated obesity: a cardiovascular magnetic resonance study

BACKGROUND

Obesity often exists alongside comorbidities and increases the risk of heart failure and cardiovascular mortality. However, the specific effects of obesity on cardiac structure and function have not been clarified. This study set out to evaluate left ventricular (LV) geometric and functional changes using cardiovascular magnetic resonance imaging (CMR) in adults with uncomplicated obesity.

METHODS

Forty-eight patients with uncomplicated obesity [body mass index (BMI) mean ± SD: 29.8±2.1 kg/m2] and 25 healthy controls were included in this study. CMR was used to assess LV geometry, global systolic function, and strains, and to quantify epicardial adipose tissue (EAT). Body composition was measured by dual X-ray absorptiometry.

RESULTS

Compared with healthy controls, patients with obesity had increased LV size, mass, and myocardial thickness, and impaired myocardial contractility, with lower global radial, circumferential, and longitudinal peak strains (PS), and circumferential and longitudinal peak diastolic strain rates (PDSR; all P<0.05). Multivariable linear regression showed that BMI was independently associated with LV maximum myocardial thickness (LVMMT) (β=0.197, P=0.016). Visceral adipose tissue (VAT) was independently associated with LV global longitudinal PS (β=-2.684, P=0.001), and both longitudinal (β=-0.192, P=0.002) and circumferential (β=-0.165, P=0.014) PDSR. Homeostasis model assessment of insulin resistance (HOMA-IR) was mildly correlated with BMI (r=0.327) and body fat percentage (BF%) (r=0.295) in patients with obesity (all P<0.05). HOMA-IR was independently associated with LV global circumferential PS (β=-0.276, P=0.04) and PDSR (β=-0.036, P=0.026).

CONCLUSIONS

Extensive LV geometric remodeling and marked changes in cardiac strains were observed in adults with obesity. Tissue tracking with CMR can reveal subclinical impaired ventricular function with preserved LV ejection fraction in such patients. BMI was independently related to LV remodeling in obesity. HOMA-IR and VAT are potentially superior to BMI as predictors of subclinical dysfunction, assessed by strain, in obesity.

TRIAL REGISTRY

This study has been registered with the Chinese Clinical Trial Registry (ID: ChiCTR1900026476; Effect of lifestyle intervention on metabolism of obese patients based on smart phone software).

Novel oral edaravone attenuates diastolic dysfunction of diabetic cardiomyopathy by activating the Nrf2 signaling pathway

Oxidative stress plays a crucial role in the pathophysiology of diastolic dysfunction associated with diabetic cardiomyopathy. Novel oral edaravone (OED) alleviates oxidative stress by scavenging free radicals and may be suitable for the treatment of chronic diseases such as diabetic cardiomyopathy. Oral administration of OED to type 2 diabetic rats (induced by high-sugar/high-fat diet and intraperitoneal injection of streptozotocin) for 4 w decreased malondialdehyde and increased superoxide dismutase. Moreover, it significantly improved ratios of early to late diastolic peak velocity, myocardium hypertrophy accompanied by decreased cross-sectional areas of cardiomyocytes, the proportion of apoptotic cells, collagen volume fractions, and deposition of collagen I/III. In H9c2 cells, OED reduced reactive oxygen species, cell surface area, and numbers of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling-positive cells induced by glucolipotoxicity. OED remarkably upregulated expression of the nuclear factor E2-related factor (Nrf2) signaling pathway both in vivo and in vitro. In addition, OED promoted Nrf2 nuclear translocation and upregulated nicotinamide adenine dinucleotide phosphate quinone oxidoreductase and heme oxygenase. Silencing of Nrf2 abolished the protective effect of OED in H9c2 cells. Our findings demonstrate that OED has the therapeutic potential to ameliorate diastolic dysfunction associated with diabetic cardiomyopathy. Its effect was mainly achieved by attenuating hyperglycemia and hyperlipidemia-induced cardiomyocyte hypertrophy, apoptosis, and fibrosis by activating the Nrf2 signaling pathway.

A presystolic wave could easily detect subclinical left ventricular dysfunction in prediabetic patients with no history of hypertension

BACKGROUND

Prediabetes is associated with left ventricular (LV) systolic and diastolic dysfunction. A presystolic wave (PSW) is detected on late diastole from the Doppler examination of the LV outflow tract and is related to LV dysfunction. LV dysfunction could be detected with different echocardiographic methods, including conventional Doppler and Tissue Doppler imaging (TDI), 2D speckle tracking echocardiography, and myocardial performance index (MPI). In this study, we aimed to investigate the association of the presence of PSW with LV dysfunction assessed by different echocardiographic methods.

METHODS

A total of 137 prediabetic normotensive patients were enrolled in this study. Eighty-one (59.1%) patients had a PSW and 36 (40.9%) patients had not PSW on the Doppler examinations. Echocardiographic features were compared between these groups. LV dysfunction was determined based on MPI, LV global longitudinal strain (LVGLS), and conventional Doppler and TDI measurements.

RESULTS

There were no differences between groups regarding clinical and laboratory parameters, except LDL, which was significantly higher in the PSW-positive group. The PSW-positive group had lower E, Em, Ea, E/A, Em/Am, Ea/Aa, LVGLS and higher A, Am, Aa, E/e', isovolumetric relaxation time, and MPI than PSW-negatives. PSW velocity was moderately correlated with MPI (R = .33, p = .003) and LVGLS (R = .35, p = .001). The presence of PSW was independently associated with LV dysfunction assessed by MPI (OR = 3.87, p < .001), LVGLS (OR = 10.29, p < .001), and conventional Doppler and TDI parameters (OR = 8.87, p < .001).

CONCLUSION

PSW was significantly associated with subclinical LV dysfunction in prediabetic normotensive patients assessed with three echocardiographic methods.

Evidence for human diabetic cardiomyopathy

Growing interest has been accumulated in the definition of worsening effects of diabetes in the cardiovascular system. This is associated with epidemiological data regarding the high incidence of heart failure (HF) in diabetic patients. To investigate the detrimental effects both of hyperglycemia and insulin resistance, a lot of preclinical models were developed. However, the evidence of pathogenic and histological alterations of the so-called diabetic cardiomyopathy (DCM) is still poorly understood in humans. Here, we provide a stringent literature analysis to investigate unique data regarding human DCM. This approach established that lipotoxic-related events might play a central role in the initiation and progression of human DCM. The major limitation in the acquisition of human data is due to the fact of heart specimen availability. Postmortem analysis revealed the end stage of the disease; thus, we need to gain knowledge on the pathogenic events from the early stages until cardiac fibrosis underlying the end-stage HF.

Potential determinants of the E/e' ratio in non-dialysis compared with dialysis patients

Aim

We hypothesized that arterial function and N‐terminal natriuretic peptide (NT‐proBNP) levels as a marker of volume overload, relate differently to E/e′ as an index of diastolic function in dialysis compared with non‐dialysis patients with chronic kidney disease. We further examined whether cardiovascular risk factors attenuated these relationships.

Methods

We assessed cardiovascular risk factors and determined arterial function indices by applanation tonometry using SphygmoCor software and E/e′ by echocardiography in 103 (62 non‐dialysis and 41 dialysis) patients.

Results

In established confounder adjusted analysis, dialysis status impacted the pulse wave velocity‐E/e′ relationship (interaction p = .01) but not the NT‐proBNP level‐E/e′ association (interaction p = .1). Upon entering arterial function measures and NT‐proBNP levels simultaneously in regression models, arterial function measures were associated with E/e′ (p = .008 to .04) in non‐dialysis patients whereas NT‐proBNP levels were related to E/e′ in dialysis patients (p = .009 to .04). Bivariate associations were found between diabetes (p < .0001) and E/e′ in non‐dialysis patients, and haemoglobin concentrations and E/e′ (p = .02) in those on dialysis. Upon adjustment for diabetes in non‐dialysis patients, only central pulse pressure remained associated with E/e′ (p = .02); when haemoglobin concentrations were adjusted for in dialysis patients, NT‐proBNP levels were no longer associated with E/e′ (p = .2). In separate models, haemoglobin levels were associated with E/e′ independent of left ventricular mass index and preload and afterload measures (p = .02 to .03).

Conclusion

The main determinants of E/e′ may differ in non‐dialysis compared with dialysis patients. These include arterial function and diabetes in non‐dialysis patients, and volume overload and anaemia in dialysis patients.

Impaired diastolic function is prevalent and problematic in people with chronic kidney disease. Using the ratio of E to e′ as a measure of impaired diastolic function, the factors most strongly associated with this metric were different depending on whether participants had dialysis‐dependent CKD or not.

Echocardiographic evaluation of the effect of poor blood glucose control on left ventricular function and ascending aorta elasticity

BACKGROUND AND AIMS

Type 2 diabetes mellitus (T2DM) is associated with high cardiovascular risk. Preclinical left ventricular (LV) dysfunction and subclinical arterial stiffness have been documented in patients with T2DM. The aims of this study were to investigate whether there were any differences in LV function and ascending aorta elasticity between T2DM patients with controlled [defined as glycosylated hemoglobin (HbA1c) <6.5%] and uncontrolled (HbA1c ≥6.5%) blood glucose.

METHODS

We studied 86 T2DM patients: 42 T2DM patients with controlled blood glucose (controlled T2DM group) and 44 T2DM patients with uncontrolled blood glucose (uncontrolled T2DM group), and 40 healthy subjects as control. They all underwent transthoracic echocardiography examination, LV systolic function was evaluated by global longitudinal strain (GLS) and LV diastolic function was defined as the ratio of the early diastolic transmitral flow velocity (E) to average mitral annular velocity (e¯). Ascending aorta inner diameters and brachial blood pressure were measured to calculate ascending aorta elastic parameters: compliance (C), distensibility (D), strain (S), stiffness index (SI), Peterson's elastic modulus (EM).

RESULTS

Compared to control, T2DM patients had reduced GLS, increased E/e ̅ and impaired ascending aorta elasticity. Furthermore, LV function and ascending aorta elasticity were more severely damaged in uncontrolled T2DM group compared with controlled T2DM group. By Pearson correlation analysis, the level of HbA_1c was independently associated with the parameters of the LV function and ascending aorta elasticity.

CONCLUSIONS

T2DM can impair the LV myocardial function and ascending aorta elastic properties, which may be further impaired by poor blood glucose control.

Novel technologies in the management of heart failure with preserved ejection fraction: a promise during the time of disappointment from pharmacological approaches?

PURPOSE OF REVIEW

Despite numerous attempts, none of a wide variety of tested drugs achieved meaningful improvement in the outcomes of heart failure with preserved ejection fraction (HFpEF), making new therapeutic strategies a major unmet medical need. The medical device industry embraced the challenge, developing novel technologies directed to face specific aspects of the pathophysiology of HFpEF. This review focuses on some of the most promising technologies attaining meaningful clinical progress recently in the field of HFpEF therapy.

RECENT FINDINGS

Implantable pulmonary artery pressure, monitoring for optimization of medical therapy, proved to be beneficial in heart failure admissions in a large postmarketing clinical study. Investigational devices, such as inter-atrial shunts and transvenous phrenic nerve stimulators for the treatment of central sleep apnea with Cheyne-Stokes breathing, are currently being evaluated in HFpEF cohorts in recent trials.

SUMMARY

Device-based therapies for HFpEF demonstrated encouraging safety and efficacy results in various stages of the disease. Further efforts are needed to ensure that these devices will reach clinical use and contribute to the management of HFpEF patients.

Significant Association Between Left Ventricular Diastolic Dysfunction, Left Atrial Performance and Liver Stiffness in Patients with Metabolic Syndrome and Non-Alcoholic Fatty Liver Disease

PURPOSE

The constitutive elements of the metabolic syndrome (MetS) are linked with both non-alcoholic fatty liver disease (NAFLD) and cardiovascular disease. Controlled attenuation parameter (CAP), and vibration controlled transient elastography (VCTE), are able to detect and quantify NAFLD, while conventional and two-dimensional speckle tracking echocardiography (2D-STE) is capable to identify subclinical changes in cardiac function. We wanted to evaluate whether there is any correspondence between left ventricular (LV) diastolic dysfunction and different degrees of liver steatosis and fibrosis in MetS subjects with NAFLD.

PATIENTS AND METHODS

A total of 150 adult subjects having MetS and a normal left ventricular (LV) systolic function were recorded in the study, while 150 age- and sex- matched adults without MetS were enrolled as controls. NAFLD was established by VCTE and CAP. The left heart systolic and diastolic function was evaluated by conventional and 2D-ST echocardiography. Left atrial (LA) stiffness was calculated as the ratio between the E/A ratio and the LA reservoir-strain.

RESULTS

In univariate regression analysis, the variables associated with LV diastolic dysfunction in MetS patients were: liver steatosis grade ≥2, liver fibrosis grade ≥2, the longitudinal LA peak strain during the reservoir phase, the LA strain rate during ventricular contraction and the LA stiffness. In multivariate logistic regression, two variables were selected as independent predictors of LV diastolic dysfunction, namely the liver stiffness (P=0.0003) and the LA stiffness (P<0.0001). LA stiffness predicted subclinical LV diastolic dysfunction in MetS patients with a sensitivity of 45% and a specificity of 96% when using a cut-off value >0.38, and was significantly correlated with liver steatosis stage ≥2 and liver fibrosis stage ≥2.

CONCLUSION

The present study confirms the association between liver stiffness, LA stiffness and LV diastolic dysfunction in MetS patients. Our study suggests that liver elastography and 2D-STE should become habitual assessments in MetS patients.

[Relationship between left ventricular diastolic dysfunction and coronary disease in type 2 diabetes mellitus]

INTRODUCTION

Type 2 diabetes is associated with an increased risk of coronary disease and is the leading cause of morbidity and mortality in this population. The main objective of our work is to study the correlation of diastolic function of the left ventricle with coronary disease in type 2 diabetics.

MATERIAL AND METHODS

Analytical cross-sectional, monocentric prospective-looking study of 703 type 2 diabetic patients performed at the Military Regional Hospital of Constantine over a period of 04 years (2016-2019). We excluded 338 patients who did not receive coronary angiography; thus 365 patients are ultimately analyzed. Evaluation of diastolic function was performed by two-dimensional transthoracic echocardiography with the search of coronary disease. The data was analyzed using the Epi Info 7.2.1.0 with study of the relationship of the diastolic function to coronary disease by multiple logistic regression.

RESULTS

The average age of our final cohort is 57,7±6,5 years, an average of 7.4±1.8% of glycated hemoglobin, an average of 5,8±4,1 years of diabetes, a sex ratio to 1.27. 49.3% had diastolic dysfunction. The prevalence of coronary disease is 32,9%. In multivariate analysis; diastolic dysfunction is correlated with coronary involvement significantly (OR=2.02, _95% CI [1.50 - 2.90], p=0.02).

CONCLUSION

The prevalence of diastolic dysfunction is high in type 2 diabetics and is significantly correlated with coronary heart disease.

The role of insulin resistance in the relation of visceral, abdominal subcutaneous and total body fat to cardiovascular function

BACKGROUND AND AIMS

The separate cardiovascular effects of type 2 diabetes and adiposity remain to be examined. This study aimed to investigate the role of insulin resistance in the relations of visceral (VAT), abdominal subcutaneous (aSAT) adipose tissue and total body fat (TBF) to cardiovascular remodeling.

METHODS AND RESULTS

In this cross-sectional analysis of the population-based Netherlands Epidemiology of Obesity study, 914 middle-aged individuals (46% men) were included. Participants underwent magnetic resonance imaging. Standardized linear regression coefficients (95%CI) were calculated, adjusted for potential confounding factors. All fat depots and insulin resistance (HOMA-IR), separate from VAT and TBF, were associated with lower mitral early and late peak filling rate ratios (E/A): -0.04 (-0.09;0.01) per SD (54 cm²) VAT; -0.05 (-0.10;0.00) per SD (94 cm²) aSAT; -0.09 (-0.16;-0.02) per SD (8%) TBF; -0.11 (-0.17;-0.05) per 10-fold increase in HOMA-IR, whereas VAT and TBF were differently associated with left ventricular (LV) end-diastolic volume: -8.9 (-11.7;-6.1) mL per SD VAT; +5.4 (1.1;9.7) mL per SD TBF. After adding HOMA-IR to the model to evaluate the mediating role of insulin resistance, change in E/A was -0.02 (-0.07;0.04) per SD VAT; -0.03 (-0.08;0.02) per SD aSAT; -0.06 (-0.13;0.01) per SD TBF, and change in LV end-diastolic volume was -7.0 (-9.7;-4.3) mL per SD VAT. In women, adiposity but not HOMA-IR was related to higher aortic arch pulse wave velocity.

CONCLUSION

Insulin resistance was associated with reduced diastolic function, separately from VAT and TBF, and partly mediated the associations between adiposity depots and lower diastolic function.

Association Between Subclinical Left Ventricular Myocardial Systolic Dysfunction Detected by Strain and Strain‑Rate Imaging and Liver Steatosis and Fibrosis Detected by Elastography and Controlled Attenuation Parameter in Patients with Metabolic Syndrome

PURPOSE

The components of metabolic syndrome (MS) are risk factors for developing both cardiovascular disease (CVD) and non-alcoholic fatty liver disease (NAFLD). Strain (SI) and strain‑rate imaging (SRI) are able to recognize early changes in cardiac function. Vibration-controlled transient elastography (VCTE) and controlled attenuation parameter (CAP) detect and quantify liver fibrosis and steatosis. We aimed to assess whether there is any correlation between liver fibrosis and steatosis and left ventricular (LV) dysfunction in MS patients.

PATIENTS AND METHODS

A total of 150 adults with MS were registered in the study. They were compared with a control group of 150 age- and sex-matched adults without MS. After the classic echocardiographic assessment of LV function, two-dimensional speckle echocardiography (2D-STE) was used to evaluate LV peak systolic strain (S) and peak systolic strain rate (SR), while liver steatosis and fibrosis were evaluated by VCTE and CAP.

RESULTS

LV diastolic dysfunction was significantly more frequent among the patients with MS. We found significant differences between the two groups regarding the presence of subtle LV systolic dysfunction, detected by reduced values of S and SR. The risk for LV diastolic dysfunction was 3.6 times higher in MS with severe steatosis and 8 times higher in patients with severe fibrosis, P<0.0001. The risk for LV systolic dysfunction was double in MS with severe steatosis and 1.7 times higher in MS with severe fibrosis, P<0.0001.

CONCLUSION

In MS patients with normal LV ejection fraction, conventional echocardiography parameters identified diastolic LV dysfunction, while SI and SRI identified subtle impairment of systolic LV dysfunction. The presence of hepatic steatosis and fibrosis increases significantly the risk for cardiac dysfunction in MS patients (P<0.0001).

Mitochondrial Dysfunction in Diabetic Cardiomyopathy: The Possible Therapeutic Roles of Phenolic Acids

As the powerhouse of the cells, mitochondria play a very important role in ensuring that cells continue to function. Mitochondrial dysfunction is one of the main factors contributing to the development of cardiomyopathy in diabetes mellitus. In early development of diabetic cardiomyopathy (DCM), patients present with myocardial fibrosis, dysfunctional remodeling and diastolic dysfunction, which later develop into systolic dysfunction and eventually heart failure. Cardiac mitochondrial dysfunction has been implicated in the development and progression of DCM. Thus, it is important to develop novel therapeutics in order to prevent the progression of DCM, especially by targeting mitochondrial dysfunction. To date, a number of studies have reported the potential of phenolic acids in exerting the cardioprotective effect by combating mitochondrial dysfunction, implicating its potential to be adopted in DCM therapies. Therefore, the aim of this review is to provide a concise overview of mitochondrial dysfunction in the development of DCM and the potential role of phenolic acids in combating cardiac mitochondrial dysfunction. Such information can be used for future development of phenolic acids as means of treating DCM by alleviating the cardiac mitochondrial dysfunction.

Short-and long-term administration of imeglimin counters cardiorenal dysfunction in a rat model of metabolic syndrome

INTRODUCTION

Imeglimin, a glucose-lowering agent targeting mitochondrial bioenergetics, decreases reactive oxygen species (ROS) overproduction and improves glucose homeostasis. We investigated whether this is associated with protective effects on metabolic syndrome-related left ventricular (LV) and vascular dysfunctions.

METHODS

We used Zucker fa/fa rats to assess the effects on LV function, LV tissue perfusion, LV oxidative stress and vascular function induced by imeglimin administered orally for 9 or 90 days at a dose of 150 mg/kg twice daily.

RESULTS

Compared to untreated animals, 9- and 90-day imeglimin treatment decreased LV end-diastolic pressure and LV end-diastolic pressure-volume relation, increased LV tissue perfusion and decreased LV ROS production. Simultaneously, imeglimin restored acetylcholine-mediated coronary relaxation and mesenteric flow-mediated dilation. One hour after imeglimin administration, when glucose plasma levels were not yet modified, imeglimin reduced LV mitochondrial ROS production and improved LV function. Ninety-day imeglimin treatment reduced related LV and kidney fibrosis and improved kidney function.

CONCLUSION

In a rat model, mimicking Human metabolic syndrome, imeglimin immediately countered metabolic syndrome-related cardiac diastolic and vascular dysfunction by reducing oxidative stress/increased NO bioavailability and improving myocardial perfusion and after 90-day treatment myocardial and kidney structure, effects that are, at least in part, independent from glucose control.

Left ventricular myocardial deformation: a study on diastolic function in the Chinese male population and its relationship with fat distribution

Background

Obesity has become an epidemic in China with its increased prevalence, especially in the male population. Disparities in fat distribution rather than increasing body mass index (BMI) confer the risk of different diseases, including cardiac abnormalities. Therefore, early detection of cardiac abnormalities is important for treatment to reverse the progression to heart failure. Nowadays, strain analysis based on cardiac magnetic resonance (CMR) imaging has been established to assess myocardial function in diverse cardiac diseases. We aimed to assess the relationship between fat distribution and subclinical diastolic dysfunction in obese Chinese men assessed by deformation registration algorithm (DRA)-based myocardial strain rate (SR) analysis.

Methods

A total of 115 male participants with different BMI underwent CMR scanning using a 1.5T MAGNETOM Aera (Siemens Healthcare, Erlangen, Germany) and computed tomography (CT) scan. All the participants were enrolled from September 2017 to April 2018. They were classified into 3 groups according to their BMIs with 23 and 27.5 kg/m² being the cutoff values. A Trufi-Strain prototype software (version 2.0, Siemens Healthcare, Erlangen, Germany) was used to quantify SR in both early and late diastole from CMR cine images. Ratios of early and late SRs were calculated. Areas of epicardial and pericardial adipose tissue (EAT and PAT) were measured on a single 4-chamber-view slice of cine images. Volumes of visceral and subcutaneous adipose tissue (VAT and SAT) were acquired semi-automatically from CT images using the dedicated software Cardiac Risk2.0 (Siemens Healthcare). Waist and hip circumferences were manually measured (WC and HC). Analysis of variance or nonparametric tests, along with correlation and stepwise multivariate regression analysis models, was applied for statistical analysis.

Results

Peak late diastolic SRs were higher in obese men compared with their lean counterparts [-36.25±10.46 vs. -29.46±8.17, 66.97±18.58 vs. 45.62 (42.44, 55.96), and 56.81±15.07 vs. 41.40±6.41 for radial, circumferential, and longitudinal SRs, respectively; P<0.05]. All SR ratios in the obese subgroups were lower than those of lean men (3.12±1.14 vs. 4.63±1.24, 2.12±0.58 vs. 2.96±0.62 and 1.63±0.50 vs. 2.20±0.63 for radial, circumferential, and longitudinal directions, respectively; P<0.05). EAT was a significant predictor of diastolic function assessed by radial and circumferential SR ratios (β=-0.439 and -0.337 respectively; all P<0.001), while VAT was a significant predictor of circumferential and longitudinal SR ratios (β=-0.216 and -0.355, respectively, P<0.05).

Conclusions

Decreased LV diastolic function assessed by DRA-based SR analysis in obesity is associated with fat distribution. Furthermore, EAT and VAT might be better predictors of a decrease of diastolic function in obese Chinese men than BMI.

Sodium-glucose co-transporter 2 inhibitors and heart failure-the present and the future

Type 2 diabetes mellitus is associated with an increased risk of heart failure. The prevalence of type 2 diabetes mellitus is on an upward trend. Heart failure represents one of the major causes for hospitalisation and mortality despite advances in management. Recent cardiovascular outcome trials have demonstrated that sodium-glucose co-transporter 2 inhibitors, which were introduced to the market in 2013, can incur a clinically significant risk reduction in heart failure outcomes in such patients. In this review, we discuss the epidemiology and pathophysiology of heart failure in diabetes and explore the landmark trials, the potential mechanisms of benefit of SGLT-2 inhibitors in heart failure, how the trials have led to major changes in treatment guidelines, and future potential directions for use of these drugs, including in those without diabetes.

Echocardiographic Changes in Newly Diagnosed Type 2 Diabetes Mellitus Patients with and without Hypertension

Background

Whether type 2 diabetes mellitus (T2DM) is independently associated with structural heart abnormalities is controversial because of confounders associated with T2DM. This study aimed to investigate echocardiographic features in patients with newly diagnosed T2DM, exploring changes in cardiac structure and function.

Material/Methods

This was a retrospective study of new T2DM cases treated at the Second People’s Hospital Affiliated to Nanjing Medical University (Changzhou) in 2014–2016. In all, 128 T2DM cases were included (62 hypertensive and 66 non-hypertensive individuals). Controls were selected among individuals who underwent examination at the same department/period. Interventricular septal thickness (IVST), left ventricular end-diastolic diameter (LVEDD), posterior left ventricular wall thickness (PWTD), left ventricle mass (LVM), end-diastolic thickness of left ventricular posterior wall (Dd), aortic root diameter, left atrial diameter (LAd), left atrial diameter fraction-shortening values, and left ventricular ejection fraction (LVEF) were determined routinely.

Results

IVST, LVEDD, PWTD, Dd, LAd, and left atrial diameter fraction-shortening values were larger in patients with T2DM (all P<0.05 vs. controls). LVM was higher in T2DM patients (median, 57.12 vs. 54.77 g, P=0.001). There were no differences in aortic root diameter and EF (both P>0.05). Multivariable analysis showed that IVST (OR=1.33, 95% CI: 1.01–1.76, P=0.04), LAd (OR=1.16, 95% CI: 1.07–1.25, P<0.001), TGs (OR=1.34, 95% CI: 1.09–1.63, P=0.005), and HDL (OR=1.46, 95% CI: 1.02–2.08, P=0.04) were independently associated with hypertension in patients with T2DM.

Conclusions

Patients with newly diagnosed T2DM already display structural heart abnormalities. LAd and IVST are independently associated with hypertension in these patients, probably contributing to increased cardiovascular risk.

Exercise Training Promotes Cardiac Hydrogen Sulfide Biosynthesis and Mitigates Pyroptosis to Prevent High-Fat Diet-Induced Diabetic Cardiomyopathy

Obesity increases the risk of developing diabetes and subsequently, diabetic cardiomyopathy (DMCM). Reduced cardioprotective antioxidant hydrogen sulfide (H₂S) and increased inflammatory cell death via pyroptosis contribute to adverse cardiac remodeling and DMCM. Although exercise training (EX) has cardioprotective effects, it is unclear whether EX mitigates obesity-induced DMCM by increasing H₂S biosynthesis and mitigating pyroptosis in the heart. C57BL6 mice were fed a high-fat diet (HFD) while undergoing treadmill EX for 20 weeks. HFD mice developed obesity, hyperglycemia, and insulin resistance, which were reduced by EX. Left ventricle pressure-volume measurement revealed that obese mice developed reduced diastolic function with preserved ejection fraction, which was improved by EX. Cardiac dysfunction was accompanied by increased cardiac pyroptosis signaling, structural remodeling, and metabolic remodeling, indicated by accumulation of lipid droplets in the heart. Notably, EX increased cardiac H₂S concentration and expression of H₂S biosynthesis enzymes. HFD-induced obesity led to features of type 2 diabetes (T2DM), and subsequently DMCM. EX during the HFD regimen prevented the development of DMCM, possibly by promoting H₂S-mediated cardioprotection and alleviating pyroptosis. This is the first report of EX modulating H₂S and pyroptotic signaling in the heart.

Cardiac magnetic resonance feature tracking for quantifying right ventricular deformation in type 2 diabetes mellitus patients

To determine the feasibility of deformation analysis in the right ventricle (RV) using cardiovascular magnetic resonance myocardial feature tracking (CMR-FT) in type 2 diabetes mellitus (T2DM) patients. We enrolled 104 T2DM patients, including 14 with impaired right ventricular ejection fraction (RVEF) and 90 with preserved RVEF, and 26 healthy controls in this prospective study. CMR was used to determine RV feature-tracking parameters. RV strain parameters were compared among the controls, patients with preserved and reduced RVEF. Binary logistic regression was used to predict RV dysfunction. Receiver operating characteristic analysis was used to assess the diagnostic accuracy. The agreement was tested by Bland-Altman analysis. Compared with controls, longitudinal and circumferential global peak strain (PS) and PS at mid-ventricular, apical slices were significantly decreased in T2DM patients with or without reduced RVEF (p < 0.05). Within the T2DM patients, the global longitudinal PS (GLPS) and the longitudinal PS at mid-ventricular segments were significantly reduced in the reduced RVEF group than in preserved RVEF groups (p < 0.05). GLPS was an independent predictor of RV dysfunction (odds ratio: 1.246, 95% CI: 1.037-1.496; p = 0.019). The GLPS demonstrated greater diagnostic accuracy (area under curve: 0.716) to predict RV dysfunction. On Bland-Altman analysis, global circumferential PS and GLPS had the best intra- and inter-observer agreement, respectively. In T2DM patients, CMR-FT could quantify RV deformation and identify subclinical RV dysfunction in those with normal RVEF. Further, RV strain parameters are potential predictors for RV dysfunction in T2DM patients.

Impact of acute hyperglycemia on layer-specific left ventricular strain in asymptomatic diabetic patients: an analysis based on two-dimensional speckle tracking echocardiography

BACKGROUND

Hyperglycemia has detrimental effect on ischemic myocardium, but the impact of acute hyperglycemia on the myocardium in asymptomatic diabetic patients has not been fully elucidated. Thus, this follow-up study was aimed to investigate the effects and reversibility of acute hyperglycemia on regional contractile function of left ventricle (LV) in diabetic patients without cardiovascular disease.

METHODS

The two-dimensional speckle tracking echocardiography (2D-STE), including multilayer strain analysis, was used for evaluation of global and regional LV function in asymptomatic, normotensive patients with uncomplicated diabetes, with acute hyperglycemia ( ≥ 11.1 mmol/l) (Group A, n = 67), or with optimal metabolic control (fasting plasma glucose < 7 mmol/l and HbA1c < 7%) (Group B, n = 20), while 20 healthy individuals served as controls (Group C). In group A, after 72 h of i.v. continuous insulin treatment (at the time euglycemia was achieved) (second examination) and after 3 months following acute hyperglycemia (third examination) 2D-STE was repeated.

RESULTS

Global longitudinal strain (GLS) (- 19.6 ± 0.4%) in Group A was significantly lower in comparison to both groups B (- 21.3 ± 0.4%; p < 0.05) and C (- 21.9 ± 0.4%; p < 0.01) at baseline, while we could not detect the differences between groups B and C. Peak systolic longitudinal endocardial (Endo), mid-myocardial (Mid) and epicardial (Epi) layer strain were significantly lower in group A at baseline compared to both groups B and C. Deterioration in peak systolic circumferential strain was observed at basal LV level, in all three layers (Endo, Mid and Epi) and in mid-cavity LV level in Epi layer in group A in comparison to group C. Moreover, in group A, after euglycemia was achieved (at second and third examination) GLS, as well as peak longitudinal and circumferential strain remain the same.

CONCLUSION

Acute hyperglycemia in asymptomatic diabetic patients has significant negative effects on systolic LV myocardial mechanics primarily by reducing GLS and multilayer peak systolic longitudinal and circumferential strain which was not reversible after three months of good glycemic control.

Metabolic Syndrome Exacerbates Pulmonary Hypertension due to Left Heart Disease

RATIONALE

Pulmonary hypertension (PH) due to left heart disease (LHD), or group 2 PH, is the most prevalent form of PH worldwide. PH due to LHD is often associated with metabolic syndrome (MetS). In 12% to 13% of cases, patients with PH due to LHD display vascular remodeling of pulmonary arteries (PAs) associated with poor prognosis. Unfortunately, the underlying mechanisms remain unknown; PH-targeted therapies for this group are nonexistent, and the development of a new preclinical model is crucial. Among the numerous pathways dysregulated in MetS, inflammation plays also a critical role in both PH and vascular remodeling.

OBJECTIVE

We hypothesized that MetS and inflammation may trigger the development of vascular remodeling in group 2 PH.

METHODS AND RESULTS

Using supracoronary aortic banding, we induced diastolic dysfunction in rats. Then we induced MetS by a combination of high-fat diet and olanzapine treatment. We used metformin treatment and anti-IL-6 (interleukin-6) antibodies to inhibit the IL-6 pathway. Compared with sham conditions, only supracoronary aortic banding+MetS rats developed precapillary PH, as measured by both echocardiography and right/left heart catheterization. PH in supracoronary aortic banding+MetS was associated with macrophage accumulation and increased IL-6 production in lung. PH was also associated with STAT3 (signal transducer and activator of transcription 3) activation and increased proliferation of PA smooth muscle cells, which contributes to remodeling of distal PA. We reported macrophage accumulation, increased IL-6 levels, and STAT3 activation in the lung of group 2 PH patients. In vitro, IL-6 activates STAT3 and induces human PA smooth muscle cell proliferation. Metformin treatment decreased inflammation, IL-6 levels, STAT3 activation, and human PA smooth muscle cell proliferation. In vivo, in the supracoronary aortic banding+MetS animals, reducing IL-6, either by anti-IL-6 antibody or metformin treatment, reversed pulmonary vascular remodeling and improve PH due to LHD.

CONCLUSIONS

We developed a new preclinical model of group 2 PH by combining MetS with LHD. We showed that MetS exacerbates group 2 PH. We provided evidence for the importance of the IL-6-STAT3 pathway in our experimental model of group 2 PH and human patients.

Can blood glucose value really be referred to as a metabolic parameter?

In clinical guidelines, near-normoglycaemia is recommended as the basic therapeutic target in diabetes mellitus. This proposal suggests that euglycaemia is associated with eumetabolism and that hyperglycaemia is an indicator of dysmetabolism. The authors analysed the relationship between short/long-term blood glucose values and cellular metabolism in various pathophysiological settings. The following types of dysmetabolism are suggested: "hyperglycaemic dysmetabolism based on insulin deficiency", "hyperglycaemic dysmetabolism based on glucose toxicity", "euglycaemic dysmetabolism", "dysmetabolism of ischaemic/reperfusional origin", and "chronic stress-mediated dysmetabolism". The relationship between dysmetabolic states of various origin was also analysed. The authors conclude that the blood glucose value can only be accepted as a general metabolic parameter with marked limitations. The main arguments of this statement are that euglycaemia is not necessarily associated with eumetabolism and that acute hyperglycaemia does not necessarily indicate dysmetabolism. Identical cell metabolic performance can be supported by different biochemical energy-producing mechanisms associated with identical blood glucose values. Both positive and negative metabolic balance of cell metabolism can occur at identical blood glucose values. A further finding is that chronic hyperglycaemia acts simultaneously as a marker and as a maker of dysmetabolism; therefore, the achievement of near normoglycaemia remains the basic therapeutic goal in diabetes treatment. Insulin administration can beneficially influence dysmetabolic states of various origins. In the evolution of and interrelationships among various dysmetabolic states, the central role of chronic stress is emphasized. Discrepancies between blood glucose values and cellular metabolism are substantiated by the transporter nature of the blood glucose value; this value reflects the result of bidirectional glucose movement into and out of the tissues.

Rationale, design and study protocol of the randomised controlled trial: Diabetes Interventional Assessment of Slimming or Training tO Lessen Inconspicuous Cardiovascular Dysfunction (the DIASTOLIC study)

INTRODUCTION

Despite their young age and relatively short duration of disease, younger adults with type 2 diabetes (T2D) already have diastolic dysfunction and may be at risk of incipient heart failure. Whether weight loss or exercise training improve cardiac dysfunction in people with T2D remains to be established.

METHODS AND ANALYSIS

Prospective, randomised, open-label, blind endpoint trial. The primary aim of the study is to determine if diastolic function can be improved by either a meal replacement plan or a supervised exercise programme, compared with guideline-directed care. A total of 90 obese participants with T2D (aged 18-65 years), diabetes duration <12 years and not on insulin treatment will be randomised to either guideline-directed clinical care with lifestyle coaching, a low-energy meal replacement diet (average ≈810 kcal/day) or a supervised exercise programme for 12 weeks. Participants undergo glycometabolic profiling, cardiopulmonary exercise testing, echocardiography and MRI scanning to assesses cardiac structure and function and dual-energy X-ray absorptiometry scanning for body composition. Key secondary aims are to assess the effects of the interventions on glycaemic control and insulin resistance, exercise capacity, blood pressure, changes in body composition and association of favourable cardiac remodelling with improvements in weight loss, exercise capacity and glycometabolic control.

ETHICS AND DISSEMINATION

The study has full ethical approval, and data collection was completed in August 2018. The study results will be submitted for publication within 6 months of completion.

TRIAL REGISTRATION NUMBER

NCT02590822; Pre-results.

Magnesium supplementation improves diabetic mitochondrial and cardiac diastolic function

In heart failure and type 2 diabetes mellitus (DM), the majority of patients have hypomagnesemia, and magnesium (Mg) supplementation has improved cardiac function and insulin resistance. Recently, we have shown that DM can cause cardiac diastolic dysfunction (DD). Therefore, we hypothesized that Mg supplementation would improve diastolic function in DM. High-fat diet-induced diabetic mouse hearts showed increased cardiac DD and hypertrophy. Mice with DM showed a significantly increased E/e' ratio (the ratio of transmitral Doppler early filling velocity [E] to tissue Doppler early diastolic mitral annular velocity [e']) in the echocardiogram, left ventricular end diastolic volume (LVEDV), incidence of DD, left ventricular posterior wall thickness in diastole (PWTd), and ratio of heart weight to tibia length (HW/TL) when compared with controls. DM mice also had hypomagnesemia. Ventricular cardiomyocytes isolated from DM mice exhibited decreased mitochondrial ATP production, a 1.7- ± 0.2-fold increase of mitochondrial ROS, depolarization of the mitochondrial membrane potential, and mitochondrial Ca2+ overload. Dietary Mg administration (50 mg/ml in the drinking water) for 6 weeks increased plasma Mg concentration and improved cardiac function. At the cellular level, Mg improved mitochondrial function with increased ATP, decreased mitochondrial ROS and Ca2+ overload, and repolarized mitochondrial membrane potential. In conclusion, Mg supplementation improved mitochondrial function, reduced oxidative stress, and prevented DD in DM.