Empagliflozin lessened cardiac injury and reduced visceral adipocyte hypertrophy in prediabetic rats with metabolic syndrome

20S-O-Glc-DM treats metabolic syndrome-induced heart failure through regulating gut flora

Heart failure is a multifactorial disease, the percentage of patients with heart failure caused by metabolic syndrome is increasing year by year. The effect of gut flora dysbiosis on metabolic syndrome and heart failure has received widespread attention in recent years. Drugs to treat the condition urgently need to be discovered. C20DM, as a precursor compound of ginsenoside, is a small molecule compound obtained by biosynthetic means and is not available in natural products. In this project, we found that C20DM could improve the diversity of gut flora and elevate the expression of intestinal tight junction proteins-Occludin, Claudin, ZO-1, which inhibited the activity of the TLR4-MyD88-NF-kB pathway, and as a result, reduced myocardial inflammation and slowed down heart failure in metabolic syndrome mice. In conclusion, our study suggests that C20DM can treat heart failure by regulating gut flora, and it may be a candidate drug for treating metabolic syndrome-induced heart failure.

New insights into the cardio-renal benefits of SGLT2 inhibitors and the coordinated role of miR-30 family

Sodium-glucose co-transporter inhibitors (SGLTis) are the latest class of anti-hyperglycemic agents. In addition to inhibiting the absorption of glucose by the kidney causing glycosuria, these drugs also demonstrate cardio-renal benefits in diabetic subjects. miR-30 family, one of the most abundant microRNAs in the heart, has recently been linked to a setting of cardiovascular diseases and has been proposed as novel biomarkers in kidney dysfunctions as well; their expression is consistently dysregulated in a variety of cardio-renal dysfunctions. The mechanistic involvement and the potential interplay between miR-30 and SGLT2i effects have yet to be thoroughly elucidated. Recent research has stressed the relevance of this cluster of microRNAs as modulators of several pathological processes in the heart and kidneys, raising the possibility of these small ncRNAs playing a central role in various cardiovascular complications, notably, endothelial dysfunction and pathological remodeling. Here, we review current evidence supporting the pleiotropic effects of SGLT2is in cardiovascular and renal outcomes and investigate the link and the coordinated implication of the miR-30 family in endothelial dysfunction and cardiac remodeling. We also discuss the emerging role of circulating miR-30 as non-invasive biomarkers and attractive therapeutic targets for cardiovascular diseases and kidney diseases. Clinical evidence, as well as metabolic, cellular, and molecular aspects, are comprehensively covered.

Cardioprotection of Canagliflozin, Dapagliflozin, and Empagliflozin: Lessons from preclinical studies

Clinical and preclinical studies have elucidated the favorable effects of Inhibitors of Sodium-Glucose Cotransporter-2 (iSGLT2) in patients and animal models with type 2 diabetes. Notably, these inhibitors have shown significant benefits in reducing hospitalizations and mortality among patients with heart failure. However, despite their incorporation into clinical practice for indications beyond diabetes, the decision-making process regarding their use often lacks a systematic approach. The selection of iSGLT2 remains arbitrary, with only a limited number of studies simultaneously exploring the different classes of them. Currently, no unique guideline establishes their application in both clinical and basic research. This review delves into the prevalent use of iSGLT2 in animal models previously subjected to induced cardiac stress. We have compiled key findings related to cardioprotection across various animal models, encompassing diverse dosages and routes of administration. Beyond their established role in diabetes management, iSGLT2 has demonstrated utility as agents for safeguarding heart health and cardioprotection can be class-dependent among the iSGLT2. These findings may serve as valuable references for other researchers. Preclinical studies play a pivotal role in ensuring the safety of novel compounds or treatments for potential human use. By assessing side effects, toxicity, and optimal dosages, these studies offer a robust foundation for informed decisions, identifying interventions with the highest likelihood of success and minimal risk to patients. The insights gleaned from preclinical studies, which play a crucial role in highlighting areas of knowledge deficiency, can guide the exploration of novel mechanisms and strategies involving iSGLT2.

Multiple Benefits of Empagliflozin in PCOS: Evidence from a Preclinical Rat Model

Polycystic ovary syndrome (PCOS) is the most common complex endocrinological condition of women that is associated with infertility and metabolic disorders during the reproductive period. Recently, a great deal of research has focused on the etiopathogenesis of this disorder and the modulation of therapeutic approaches. There are still many controversies in the choice of therapy, and metformin is one of the most commonly used agents in the treatment of PCOS. Considering the link between metabolic disorders and PCOS, glycemic status is crucial in these patients, and sodium-glucose cotransporter type 2 inhibitors (SGLT2is) represent a potentially promising new therapeutic approach. These drugs have been shown to improve glucose metabolism, reduce adipose tissue, decrease oxidative stress, and protect the cardiovascular system. These data prompted us to investigate the effects of empagliflozin (EMPA) in a PCOS rat model and compare them with the effects of metformin. We confirmed that EMPA positively affects somatometric parameters, glucose and lipid metabolism, and the levels of sex hormones, as well as reduces oxidative stress and improves ovarian function and morphology. Administration of EMPA at doses of 5 mg/kg, 15 mg/kg, and 45 mg/kg during a 4-week treatment period improved, as induced by estradiol valerate and a high-fat diet, the metabolic and reproductive statuses in a PCOS rat model. The best effects, which were comparable to the effects of metformin, were achieved in groups receiving the middle and highest applied doses of EMPA. These results may prompt further clinical research on the use of EMPA in patients with PCOS.

SGLT2 inhibitors: how do they affect the cardiac cells

The first sodium-glucose cotransporter-2 inhibitor (SGLT2I), canagliflozin, was approved by the U.S. Food and Drug Administration for the treatment of type 2 diabetes in 2013. Since then, other members of this drug class (such as dapagliflozin, empagliflozin, and ertugliflozin) have become widely used. Unlike classical antidiabetic agents, these drugs do not interfere with insulin secretion or action, but instead promote renal glucose excretion. Since their approval, many preclinical and clinical studies have been conducted to investigate the diverse effects of SGLT2Is. While originally introduced as antidiabetic agents, the SGLT2Is are now recognized as pillars in the treatment of heart failure and chronic kidney disease, in patients with or without diabetes. The beneficial cardiac effects of this class have been attributed to several mechanisms. Among these, SGLT2Is inhibit fibrosis, hypertrophy, apoptosis, inflammation, and oxidative stress. They regulate mitochondrial function and ion transport, and stimulate autophagy through several underlying mechanisms. This review details the potential effects of SGLT2Is on cardiac cells.

Sodium-Glucose Cotransporter-2 Inhibitors in Patients With Acute Coronary Syndrome: A Modern Cinderella?

PURPOSE

Atherosclerotic cardiovascular disease remains a prominent global cause of mortality, with coronary artery disease representing its most prevalent manifestation. Recently, a novel class of antidiabetic medication, namely sodium-glucose cotransporter-2 (SGLT2) inhibitors, has been reported to have remarkable cardiorenal advantages for individuals with type 2 diabetes mellitus (DM), and they may reduce cardiorenal risk even in individuals without pre-existing DM. Currently, there is no evidence regarding the safety and efficacy of these drugs in acute coronary syndrome (ACS), regardless of diabetes status. This review aims to comprehensively present the available preclinical and clinical evidence regarding the potential role of SGLT2 inhibitors in the context of ACS, as adjuncts to standard-of-care treatment for this patient population, while also discussing potential short- and long-term cardiovascular benefits.

METHODS

A literature search was performed through MEDLINE (via PubMed), Cochrane Central Register of Controlled Trials, and Scopus until February 26, 2024. Eligible were preclinical and clinical studies, comprising randomized controlled trials (RCTs), real-world studies, and meta-analyses.

FINDINGS

Evidence from preclinical models indicates that the use of SGLT2 inhibitors is associated with a blunted ischemia-reperfusion injury and decreased myocardial infarct size, particularly after prior treatment. Although RCTs and real-world data hint at a potential benefit in acute ischemic settings, showing improvements in left ventricular systolic and diastolic function, decongestion, and various cardiometabolic parameters such as glycemia,body weight, and blood pressure, the recently published DAPA-MI (Dapagliflozin in Myocardial Infarction without Diabetes or Heart Failure) trial did not establish a clear advantage regarding surrogate cardiovascular end points of interest. SGLT2 inhibitors appear to provide a benefit in reducing contrast-induced acute kidney injury events in patients with ACS undergoing percutaneous coronary intervention. However, data on other safety concerns, such as treatment discontinuation because of hypotension, hypovolemia, or ketoacidosis, are currently limited.

IMPLICATIONS

Despite the well-established cardiovascular benefits observed in the general population with type 2 DM and, more recently, in other patient groups irrespective of diabetes status, existing evidence does not support the use of SGLT2 inhibitors in the context of ACS. Definitive answers to this intriguing research question, which could potentially expand the therapeutic indications of this novel drug class, require large-scale, well-designed RCTs.

Research advances in the anti-inflammatory effects of SGLT inhibitors in type 2 diabetes mellitus

Diabetes mellitus is one of the most significant global burden diseases. It is well established that a chronic, systemic, low-grade inflammatory condition is strongly correlated with type 2 diabetes mellitus (T2D) and the development of target-organ damage (TOD). Sodium-glucose cotransporter inhibitors (SGLTis), novel oral drugs for the treatment of diabetes, act mainly by reducing glucose reabsorption in proximal renal tubules and/or the intestine. Several high-quality clinical trials and large observational studies have revealed that SGLTis significantly improve cardiovascular and renal outcomes in T2D patients. Increasing evidence suggests that this is closely related to their anti-inflammatory properties, which are mainly manifested by a reduction in plasma concentrations of inflammatory biomarkers. This review analyses the potential mechanisms behind the anti-inflammatory effects of SGLTis in diabetes and presents recent evidence of their therapeutic efficacy in treating diabetes and related TOD.

Empagliflozin protects against isoprenaline-induced fibrosis in rat heart through modulation of TGF-β/SMAD pathway

AIM

Cardiac fibrosis is characterized by excessive accumulation of fibrous tissue, particularly collagens, in the myocardium. Accumulated fibrous tissue renders myocardium stiffer and reduces its contractility. Empagliflozin is an oral hypoglycemic agent with extra-diabetic functional profile toward maintaining cardiac functions. The present study aimed to examine protective effect of empagliflozin against an in-vivo model of cardiac fibrosis induced by isoprenaline and targeting TGF-β/SMAD signaling as a possible pathway responsible for such effect.

MAIN METHODS

Sixty animals were divided into six groups; the first was normal, and the second was treated with isoprenaline only (5 mg/kg/day I.P.) as a control. The third received pirfenidone (500 mg/kg/day P.O.), and the remaining groups received graded doses (5, 10, 20 mg/kg respectively) of empagliflozin for 14 days before fibrosis induction by isoprenaline (5 mg/kg/day) for 30 days.

KEY FINDINGS

Isoprenaline increased cardiac enzymes, and cardiac tissues revealed elevated concentrations of transforming growth factor β (TGF-β1), monocyte chemoattractant protein 1 (MCP-1), tumor necrosis factor α (TNF-α), and c-jun N-terminal kinase (JNK) proteins. Expression of nuclear factor kappa B (NF-κB), alpha smooth muscle actin (α-SMA), collagens, suppressor of mothers against decapentaplegic (SMADs), connective tissue growth factor (CTGF), and fibronectin was upregulated. Empagliflozin improved the histological picture of heart tissue in comparison to fibrosis developed in controls, and protected against fibrosis through significant modulation of all mentioned parameters' concentrations and expressions.

SIGNIFICANCE

Empagliflozin demonstrated a promising protective approach against biological model of cardiac fibrosis through an anti-fibrotic effect through targeting TGF-β signaling pathways.

Expanding the possibilities of using sodium-glucose cotransporter 2 inhibitors in patients with heart failure

OBJECTIVE

Aim: To study the potential mechanisms of the beneficial cardiovascular effects of sodium-glucose cotransporter 2 (SGLT-2) inhibitors, the possibilities of improving the treatment and prognosis of patients with acute heart failure (HF) during their use.

PATIENTS AND METHODS

Materials and Methods: The data analysis of literary sources has been conducted regarding the results of existing studies evaluating the clinical benefit and safety of SGLT-2 inhibitors in patients with acute heart failure.

CONCLUSION

Conclusions: The peculiarities of the pharmacological action of SGLT-2 inhibitors and the obtained research results expand the possibilities of using this group of drugs, demonstrating encouraging prospects in improving the prognosis of patients hospitalized with acute heart failure.

Empagliflozin treatment of cardiotoxicity: A comprehensive review of clinical, immunobiological, neuroimmune, and therapeutic implications

Cancer and cardiovascular disorders are known as the two main leading causes of mortality worldwide. Cardiotoxicity is a critical and common adverse effect of cancer-related chemotherapy. Chemotherapy-induced cardiotoxicity has been associated with various cancer treatments, such as anthracyclines, immune checkpoint inhibitors, and kinase inhibitors. Different methods have been reported for the management of chemotherapy-induced cardiotoxicity. In this regard, sodium-glucose cotransporter-2 inhibitors (SGLT2i), a class of antidiabetic agents, have recently been applied to manage heart failure patients. Further, SGLT2i drugs such as EMPA exert protective cardiac and systemic effects. Moreover, it can reduce inflammation through the mediation of major inflammatory components, such as Nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasomes, Adenosine 5'-monophosphate-activated protein kinase (AMPK), and c-Jun N-terminal kinase (JNK) pathways, Signal transducer and activator of transcription (STAT), and overall decreasing transcription of proinflammatory cytokines. The clinical outcome of EMPA administration is related to improving cardiovascular risk factors, including body weight, lipid profile, blood pressure, and arterial stiffness. Intriguingly, SGLT2 suppressors can regulate microglia-driven hyperinflammation affecting neurological and cardiovascular disorders. In this review, we discuss the protective effects of EMPA in chemotherapy-induced cardiotoxicity from molecular, immunological, and neuroimmunological aspects to preclinical and clinical outcomes.

Effect of SGLT2 Inhibitor on Cardiomyopathy in a Rat Model of T2DM: Possible involvement of Cardiac Aquaporins

Diabetic cardiomyopathy (DCM) causes arrhythmia, heart failure, and sudden death. Empagliflozin, an SGLT-2 (Sodium glucose co-transporter) inhibitor, is an anti-diabetic medication that decreases blood glucose levels by stimulating urinary glucose excretion. Several aquaporins (AQPs) including AQP-1-3 and - 4 and their involvement in the pathogenesis in different cardiac diseases were detected. In the current study the effect of Empagliflozin on diabetic cardiomyopathy and the possible involvement of cardiac AQPs were investigated.

METHODS

56 adult male Sprague-Dawley rats were divided into 4 groups: Control, DCM: type 2 diabetic rats, low EMPA+DCM received empagliflozin (10 mg/kg/day) and high EMPA+DCM received empagliflozin (30 mg/kg/day) for 6 weeks.

RESULTS

Administration of both EMPA doses, especially in high dose group, led to significant improvement in ECG parameters. Also, a significant improvement in biochemical and cardiac oxidative stress markers (significant decrease in serum CK-MB, and malondialdehyde while increasing catalase) with decreased fibrosis and edema in histopathological examination and a significant attenuation in apoptosis (caspase-3) and edema (AQP-1& -4).

CONCLUSION

Both doses of Empagliflozin have a cardioprotective effect and reduced myocardial tissue edema with high dose having a greater effect. This might be due to attenuation of oxidative stress, fibrosis and edema mediated through AQP-1, - 3& - 4 expression.

Signaling pathways in vascular function and hypertension: molecular mechanisms and therapeutic interventions

Hypertension is a global public health issue and the leading cause of premature death in humans. Despite more than a century of research, hypertension remains difficult to cure due to its complex mechanisms involving multiple interactive factors and our limited understanding of it. Hypertension is a condition that is named after its clinical features. Vascular function is a factor that affects blood pressure directly, and it is a main strategy for clinically controlling BP to regulate constriction/relaxation function of blood vessels. Vascular elasticity, caliber, and reactivity are all characteristic indicators reflecting vascular function. Blood vessels are composed of three distinct layers, out of which the endothelial cells in intima and the smooth muscle cells in media are the main performers of vascular function. The alterations in signaling pathways in these cells are the key molecular mechanisms underlying vascular dysfunction and hypertension development. In this manuscript, we will comprehensively review the signaling pathways involved in vascular function regulation and hypertension progression, including calcium pathway, NO-NOsGC-cGMP pathway, various vascular remodeling pathways and some important upstream pathways such as renin-angiotensin-aldosterone system, oxidative stress-related signaling pathway, immunity/inflammation pathway, etc. Meanwhile, we will also summarize the treatment methods of hypertension that targets vascular function regulation and discuss the possibility of these signaling pathways being applied to clinical work.

The lipidomic and inflammatory profiles of visceral and subcutaneous adipose tissues are distinctly regulated by the SGLT2 inhibitor empagliflozin in Zucker diabetic fatty rats

The pharmacological inhibition of sodium-glucose cotransporter 2 (SGLT2) has emerged as a treatment for patients with type 2 diabetes mellitus (T2DM), cardiovascular disease and/or other metabolic disturbances, although some of the mechanisms implicated in their beneficial effects are unknown. The SGLT2 inhibitor (SGLT2i) empagliflozin has been suggested as a regulator of adiposity, energy metabolism, and systemic inflammation in adipose tissue. The aim of our study was to evaluate the impact of a 6-week-empagliflozin treatment on the lipidome of visceral (VAT) and subcutaneous adipose tissue (SAT) from diabetic obese Zucker Diabetic Fatty (ZDF) rats using an untargeted metabolomics approach. We found that empagliflozin increases the content of diglycerides and oxidized fatty acids (FA) in VAT, while in SAT, it decreases the levels of several lysophospholipids and increases 2 phosphatidylcholines. Empagliflozin also reduces the expression of the cytokines interleukin-1 beta (IL-1β), IL-6, tumor necrosis factor-alpha (TNFα), monocyte-chemotactic protein-1 (MCP-1) and IL-10, and of Cd86 and Cd163 M1 and M2 macrophage markers in VAT, with no changes in SAT, except for a decrease in IL-1β. Empagliflozin treatment also shows an effect on lipolysis increasing the expression of hormone-sensitive lipase (HSL) in SAT and VAT and of adipose triglyceride lipase (ATGL) in VAT, together with a decrease in the adipose content of the FA transporter cluster of differentiation 36 (CD36). In conclusion, our data highlighted differences in the VAT and SAT lipidomes, inflammatory profiles and lipolytic function, which suggest a distinct metabolism of these two white adipose tissue depots after the empagliflozin treatment.

Novel Concepts in Nephron Sodium Transport: A Physiological and Clinical Perspective

The kidneys play a critical role in maintaining total body sodium (Na⁺) balance across a wide range of dietary intake, accomplished by a concerted effort involving multiple Na⁺ transporters along the nephron. Furthermore, nephron Na⁺ reabsorption and urinary Na⁺ excretion are closely linked to renal blood flow and glomerular filtration such that perturbations in either of them can modify Na⁺ transport along the nephron, ultimately resulting in hypertension and other Na⁺-retentive states. In this article, we provide a brief physiological overview of nephron Na⁺ transport and illustrate clinical syndromes and therapeutic agents that affect Na⁺ transporter function. We highlight recent advances in kidney Na⁺ transport, particularly the role of immune cells, lymphatics, and interstitial Na⁺ in regulating Na⁺ reabsorption, the emergence of potassium (K⁺) as a regulator of Na⁺ transport, and the evolution of the nephron to modulate Na⁺ transport.

Sodium-glucose Cotransporter 2 Inhibitors and Pathological Myocardial Hypertrophy

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a new type of oral hypoglycemic drugs that exert a hypoglycemic effect by blocking the reabsorption of glucose in the proximal renal tubules, thus promoting the excretion of glucose from urine. Their hypoglycemic effect is not dependent on insulin. Increasing data shows that SGLT2 inhibitors improve cardiovascular outcomes in patients with type 2 diabetes. Previous studies have demonstrated that SGLT2 inhibitors can reduce pathological myocardial hypertrophy with or without diabetes, but the exact mechanism remains to be elucidated. To clarify the relationship between SGLT2 inhibitors and pathological myocardial hypertrophy, with a view to providing a reference for the future treatment thereof, this study reviewed the possible mechanisms of SGLT2 inhibitors in attenuating pathological myocardial hypertrophy. We focused specifically on the mechanisms in terms of inflammation, oxidative stress, myocardial fibrosis, mitochondrial function, epicardial lipids, endothelial function, insulin resistance, cardiac hydrogen and sodium exchange, and autophagy.

Depot-specific adipose tissue modulation by SGLT2 inhibitors and GLP1 agonists mediates their cardioprotective effects in metabolic disease

Sodium-glucose transporter-2 inhibitors (SGLT-2i) and glucagon-like peptide 1 (GLP-1) receptor agonists are newer antidiabetic drug classes, which were recently shown to decrease cardiovascular (CV) morbidity and mortality in diabetic patients. CV benefits of these drugs could not be directly attributed to their blood glucose lowering capacity possibly implicating a pleotropic effect as a mediator of their impact on cardiovascular disease (CVD). Particularly, preclinical and clinical studies indicate that SGLT-2i(s) and GLP-1 receptor agonists are capable of differentially modulating distinct adipose pools reducing the accumulation of fat in some depots, promoting the healthy expansion of others, and/or enhancing their browning, leading to the suppression of the metabolically induced inflammatory processes. These changes are accompanied with improvements in markers of cardiac structure and injury, coronary and vascular endothelial healing and function, vascular remodeling, as well as reduction of atherogenesis. Here, through a summary of the available evidence, we bring forth our view that the observed CV benefit in response to SGLT-2i or GLP-1 agonists therapy might be driven by their ameliorative impact on adipose tissue inflammation.

Treatment of HFpEF beyond the SGLT2-Is: Does the Addition of GLP-1 RA Improve Cardiometabolic Risk and Outcomes in Diabetic Patients?

Heart failure with preserved ejection fraction (HFpEF) is a common clinical syndrome frequently seen in elderly patients, the incidence of which is steadily increasing due to an ageing population and the increasing incidence of diseases, such as diabetes, hypertension, obesity, chronic renal failure, and so on. It is a multifactorial disease with different phenotypic aspects that share left ventricular diastolic dysfunction, and is the cause of about 50% of hospitalizations for heart failure in the Western world. Due to the complexity of the disease, no specific therapies have been identified for a long time. Sodium-Glucose Co-Transporter 2 Inhibitors (SGLT2-Is) and Glucagon-Like Peptide Receptor Agonists (GLP-1 RAs) are antidiabetic drugs that have been shown to positively affect heart and kidney diseases. For SGLT2-Is, there are precise data on their potential benefits in heart failure with reduced ejection fraction (HFrEF) as well as in HFpEF; however, insufficient evidence is available for GLP-1 RAs. This review addresses the current knowledge on the cardiac effects and potential benefits of combined therapy with SGLT2-Is and GLP-1RAs in patients with HFpEF.

Benefits of SGLT2 inhibitors in arrhythmias

Some studies have shown that sodium-glucose cotransporter (SGLT) 2 inhibitors can definitively attenuate the occurrence of cardiovascular diseases such as heart failure (HF), dilated cardiomyopathy (DCM), and myocardial infarction. With the development of research, SGLT2 inhibitors can also reduce the risk of arrhythmias. So in this review, how SGLT2 inhibitors play a role in reducing the risk of arrhythmia from the perspective of electrical remodeling and structural remodeling are explored and then the possible mechanisms are discussed. Specifically, we focus on the role of SGLT2 inhibitors in Na+ and Ca2 + homeostasis and the transients of Na+ and Ca2 +, which could affect electrical remodeling and then lead to arrythmia. We also discuss the protective role of SGLT2 inhibitors in structural remodeling from the perspective of fibrosis, inflammation, oxidative stress, and apoptosis. Ultimately, it is clear that SGLT2 inhibitors have significant benefits on cardiovascular diseases such as HF, myocardial hypertrophy and myocardial infarction. It can be expected that SGLT2 inhibitors can reduce the risk of arrhythmia.

Effect of Dapagliflozin on Left Ventricular Diastolic Function in Diabetics - A Prospective Interventional Study

Objectives:

In patients with established heart failure, the SGLT2 inhibitor dapagliflozin found to alleviate the risk of worsening heart failure or cardiovascular mortality regardless of the presence of Diabetes Mellitus. To evaluate the effect of Dapagliflozin on Left Ventricular Diastolic function in Patients with Type 2 Diabetes Mellitus, to study the baseline Diastolic function in patients with type 2 diabetes mellitus and to study the Diastolic function at rest and after exercise in patients with type 2 diabetes mellitus 24 weeks after taking Dapagliflozin.

Materials and Methods:

It is a Prospective interventional Pilot study with study population consisting of T2DM who are 18 years and older with HbA1C between 7.0% to 10% and LV diastolic dysfunction of at least grade 1 on resting echocardiography. Baseline diastolic function was measured. Dapagliflozin 10 mg once daily was given to all patients for 24 weeks and then left ventricular diastolic function was measured by e’, E/A ratio, E/e’ at 24 weeks from baseline as assessed by Stress Echocardiography.

Results:

Diastolic Dysfunction grading between Baseline and post 24 weeks treatment with dapagliflozin, using Marginal Homogeneity Test showed p value <0.001 which is highly significant. Comparision of e’ at rest for baseline and post 24 weeks of treatment with dapagliflozin showed statistical significance. The e’ after exercise for baseline and post 24 weeks of treatment showed p value of <0.01. Comparision of E/e’ at rest and after exercise for baseline and post 24 weeks showed statistical significance.

Conclusion:

The diastolic function has been significantly improved after 24 weeks of using dapagliflozin. The diastolic function parameters between age and sex groups at baseline and post 24 weeks of treatment with dapagliflozin does not correlate.

Empagliflozin Ameliorates Progression From Prediabetes to Diabetes and Improves Hepatic Lipid Metabolism: A Systematic Review

Diabetes mellitus (DM) and hepatic steatosis are two of the most common metabolic syndromes that affect the health of people globally. Empagliflozin (EMPA) is a promising drug of choice for the diabetic population. Recent studies have shown its beneficial effects not only on diabetic patients but also on patients suffering from cardiac, hepatic, neurological, or pancreatic anomalies. In this paper, we systematically searched electronic databases to compile literature that focuses on EMPA’s effect on the prediabetic population, diabetic population, and hepatic lipid metabolism. We focus on the mechanism of EMPA, specifically by which it increases insulin sensitivity and fat browning and reduces fat accumulation. Overall, we hypothesized that by its effect on weight loss and reducing inflammatory markers and insulin resistance (IR), EMPA decreases the rate of prediabetes to diabetes conversion. We concluded that by improving hepatic and serum triglyceride, decreasing visceral fat, and its positive impact on hepatic steatosis, the drug improves hepatic lipid metabolism. Further research should be done on this matter.

Antiarrhythmic effects and mechanisms of sodium-glucose cotransporter 2 inhibitors: A mini review

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are a new type of oral hypoglycaemic agent with good cardiovascular protective effects. There are several lines of clinical evidence suggest that SGLT2i can significantly reduce the risks of heart failure, cardiovascular death, and delay the progression of chronic kidney disease. In addition, recent basic and clinical studies have also reported that SGLT2i also has good anti-arrhythmic effects. However, the exact mechanism is poorly understood. The aim of this review is to summarize recent clinical findings, studies of laboratory animals, and related study about this aspect of the antiarrhythmic effects of SGLT2i, to further explore its underlying mechanisms, safety, and prospects for clinical applications of it.

Assessing the risk factors for myocardial infarction in diet-induced prediabetes: myocardial tissue changes

Background

Hyperglycaemia is known to result in oxidative stress tissue injury and dysfunction. Interestingly, studies have reported hepatic and renal oxidative stress injury during prediabetes; however, any injury to the myocardium during prediabetes has not been investigated. Hence this study aims to assess changes in the myocardial tissue in an HFHC diet-induced model of prediabetes.

Methods

Male Sprague Dawley rats were randomly grouped into non-prediabetes and prediabetes (n = 6 in each group) and consumed a standard rat chow or fed a high-fat-high-carbohydrate diet respectively for a 20-week prediabetes induction period. Post induction, prediabetes was confirmed using the ADA criteria. Aldose reductase, NADH oxidase 1, superoxide dismutase, glutathione peroxide, cardiac troponins were analysed in cardiac tissue homogenate using specific ELISA kits. Lipid peroxidation was estimated by determining the concentration of malondialdehyde in the heart tissue homogenate according to the previously described protocol. Myocardial tissue sections were stained with H&E stain and analysed using Leica microsystem. All data were expressed as means ± SEM. Statistical comparisons were performed with Graph Pad instat Software using the Student's two-sided t-test. Pearson correlation coefficient was calculated to assess the association. Value of p < 0.05 was considered statistically significant.

Results

The prediabetes group showed a markedly high oxidative stress as indicated by significantly increased NADH oxidase 1 and malondialdehyde while superoxide dismutase and glutathione peroxide were decreased compared to non-prediabetes group. There was no statistical difference between cardiac troponin I and T in the non-prediabetes and prediabetes groups. Cardiac troponins had a weak positive association with glycated haemoglobin.

Conclusion

The findings of this study demonstrate that prediabetes is associated with myocardial injury through oxidative stress. Future studies are to investigate cardiac contractile function and include more cardiac biomarkers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02758-8.

Endothelial Dysfunction in Heart Failure With Preserved Ejection Fraction: What are the Experimental Proofs?

Heart failure with preserved ejection fraction (HFpEF) has been recognized as the greatest single unmet need in cardiovascular medicine. Indeed, the morbi-mortality of HFpEF is high and as the population ages and the comorbidities increase, so considerably does the prevalence of HFpEF. However, HFpEF pathophysiology is still poorly understood and therapeutic targets are missing. An unifying, but untested, theory of the pathophysiology of HFpEF, proposed in 2013, suggests that cardiovascular risk factors lead to a systemic inflammation, which triggers endothelial cells (EC) and coronary microvascular dysfunction. This cardiac small vessel disease is proposed to be responsible for cardiac wall stiffening and diastolic dysfunction. This paradigm is based on the fact that microvascular dysfunction is highly prevalent in HFpEF patients. More specifically, HFpEF patients have been shown to have decreased cardiac microvascular density, systemic endothelial dysfunction and a lower mean coronary flow reserve. Importantly, impaired coronary microvascular function has been associated with the severity of HF. This review discusses evidence supporting the causal role of endothelial dysfunction in the pathophysiology of HFpEF in human and experimental models.

Effects of the SGLT2 Inhibition on Cardiac Remodeling in Streptozotocin-Induced Diabetic Rats, a Model of Type 1 Diabetes Mellitus

Clinical trials have shown that sodium glucose co-transporter 2 (SGLT2) inhibitors improve clinical outcomes in diabetes mellitus (DM) patients. As most studies were performed in Type 2 DM, the cardiovascular effects of SGLT2 inhibition still require clarification in Type 1 DM. We analyzed the effects of SGLT2 inhibitor dapagliflozin on cardiac remodeling in rats with streptozotocin-induced diabetes, an experimental model of Type 1 DM. Methods: Male Wistar rats were assigned into four groups: control (C, n = 14); control treated with dapagliflozin (C + DAPA, n = 14); diabetes (DM, n = 20); and diabetes treated with dapagliflozin (DM + DAPA, n = 20) for 8 weeks. Dapagliflozin dosage was 5 mg/kg/day. Statistical analyses: ANOVA and Tukey or Kruskal−Wallis and Dunn. Results: DM + DAPA presented decreased blood pressure and glycemia and increased body weight compared to DM (C 507 ± 52; C + DAPA 474 ± 50; DM 381 ± 52 *; DM + DAPA 430 ± 48 # g; * p < 0.05 vs. C; # p < 0.05 vs. C + DAPA and DM + DAPA). DM echocardiogram presented left ventricular and left atrium dilation with impaired systolic and diastolic function. Cardiac changes were attenuated by dapagliflozin. Myocardial hydroxyproline concentration and interstitial collagen fraction did not differ between groups. The expression of Type III collagen was lower in DM and DM + DAPA than their controls. Type I collagen expression and Type I-to-III collagen ratio were lower in DM + DAPA than C + DAPA. DM + DAPA had lower lipid hydroperoxide concentration (C 275 ± 42; C + DAPA 299 ± 50; DM 385 ± 54 *; DM + DAPA 304 ± 40 # nmol/g tissue; * p < 0.05 vs. C; # p < 0.05 vs. DM) and higher superoxide dismutase and glutathione peroxidase activity than DM. Advanced glycation end products did not differ between groups. Conclusion: Dapagliflozin is safe, increases body weight, decreases glycemia and oxidative stress, and attenuates cardiac remodeling in an experimental rat model of Type 1 diabetes mellitus.

An Overview of the Cardiorenal Protective Mechanisms of SGLT2 Inhibitors

Sodium-glucose co-transporter 2 (SGLT2) inhibitors block glucose reabsorption in the renal proximal tubule, an insulin-independent mechanism that plays a critical role in glycemic regulation in diabetes. In addition to their glucose-lowering effects, SGLT2 inhibitors prevent both renal damage and the onset of chronic kidney disease and cardiovascular events, in particular heart failure with both reduced and preserved ejection fraction. These unexpected benefits prompted changes in treatment guidelines and scientific interest in the underlying mechanisms. Aside from the target effects of SGLT2 inhibition, a wide spectrum of beneficial actions is described for the kidney and the heart, even though the cardiac tissue does not express SGLT2 channels. Correction of cardiorenal risk factors, metabolic adjustments ameliorating myocardial substrate utilization, and optimization of ventricular loading conditions through effects on diuresis, natriuresis, and vascular function appear to be the main underlying mechanisms for the observed cardiorenal protection. Additional clinical advantages associated with using SGLT2 inhibitors are antifibrotic effects due to correction of inflammation and oxidative stress, modulation of mitochondrial function, and autophagy. Much research is required to understand the numerous and complex pathways involved in SGLT2 inhibition. This review summarizes the current known mechanisms of SGLT2-mediated cardiorenal protection.

Beneficial cardiovascular and remodeling effects of SGLT2 inhibitors: pathophysiologic mechanisms

INTRODUCTION

The intent of this paper is to review the data regarding the multipotential effects of the sodium-glucose cotransporter 2 (SGLT 2) inhibitors, their cardiovascular protective effects, and their mechanism of action.

AREAS COVERED

The SGLT2 inhibitors exert their beneficial antidiabetic and cardioprotective effects through increased glucose excretion from the kidneys, blood pressure and weight lowering, vasodilation and other potential beneficial effects. They have been used for the treatment of patients with type 2 diabetes mellitus (T2DM) as well as in patients with cardiovascular disease (CVD), coronary artery disease (CAD),and heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF). In order to get a better understanding of their mechanism of action for their multiple cardiovascular protective effects, a Medline search of the English language literature was conducted between 2015 and February 2022 and 46 pertinent papers were selected.

EXPERT OPINION

The analysis of data clearly demonstrated that the use of the SGLT2 inhibitors besides their antidiabetic effects, provide additional protection against CVD, CAD, and HFrEF and HFpEF, and death, but not stroke, in both diabetic and non-diabetic patients. Therefore, they should be preferably used for the treatment of patients with T2DM with preexisting CVD, CAD, and HFrEF and HFpEF.

Effects of Sodium-Glucose Cotransporter 2 Inhibitors on Water and Sodium Metabolism

Sodium-glucose cotransporter 2 (SGLT2) inhibitors exert hypoglycemic and diuretic effects by inhibiting the absorption of sodium and glucose from the proximal tubule. Currently available data indicate that SGLT2 inhibitors transiently enhance urinary sodium excretion and urinary volume. When combined with loop diuretics, SGLT2 inhibitors exert a synergistic natriuretic effect. The favorable diuretic profile of SGLT2 inhibitors may confer benefits to volume management in patients with heart failure but this natriuretic effect may not be the dominant mechanism for the superior long-term outcomes observed with these agents in patients with heart failure. The first part of this review explores the causes of transient natriuresis and the diuretic mechanisms of SGLT2 inhibitors. The second part provides an overview of the synergistic effects of combining SGLT2 inhibitors with loop diuretics, and the third part summarizes the mechanisms of cardiovascular protection associated with the diuretic effects of SGLT2 inhibitors.

SGLT2 inhibitor dapagliflozin prevents atherosclerotic and cardiac complications in experimental type 1 diabetes

Introduction

Cardiovascular disease (CVD) is two to five times more prevalent in diabetic patients and is the leading cause of death. Therefore, identification of novel therapeutic strategies that reduce the risk of CVD is a research priority. Clinical trials showed that reduction in the relative risk of heart failure by sodium-glucose cotransporter 2 inhibitors (SGLT2i) are partly beyond their glucose lowering effects, however, the molecular mechanisms are still elusive. Here we investigated the role of SGLT2i dapagliflozin (DAPA) in the prevention of diabetes-induced cardiovascular complications.

Methods

Type 1 diabetes was induced with streptozotocin (65 mg/bwkg, ip.) in adult, male Wistar rats. Following the onset of diabetes rats were treated for six weeks with DAPA (1 mg/bwkg/day, po.).

Results

DAPA decreased blood glucose levels (D: 37±2.7 vs. D+DAPA: 18±5.6 mmol/L; p<0.05) and prevented metabolic decline. Aortic intima-media thickening was mitigated by DAPA. DAPA abolished cardiac hypertrophy, and myocardial damage. Cardiac inflammation and fibrosis were also moderated after DAPA treatment.

Conclusions

These data support the preventive and protective role of SGLT2i in diabetes-associated cardiovascular disease. SGLT2i may provide novel therapeutic strategy to hinder the development of cardiovascular diseases in type 1 diabetes, thereby improve the outcomes.

Sodium-Glucose Co-transporter-2 Inhibitor of Dapagliflozin Attenuates Myocardial Ischemia/Reperfusion Injury by Limiting NLRP3 Inflammasome Activation and Modulating Autophagy

Background: The sodium-glucose co-transporter-2 (SGLT-2) inhibitor dapagliflozin improves cardiovascular outcomes in patients with type 2 diabetes in a manner that is partially independent of its hypoglycemic effect. These observations suggest that it may exert a cardioprotective effect by another mechanism. This study explored the effects of dapagliflozin on myocardial ischemia/reperfusion injury in a mouse model. Materials and Methods: For the in vivo I/R studies, mice received 40 mg/kg/d dapagliflozin, starting 7 days before I/R. Evans Blue/TTC double-staining was used to determine the infarct size. Serum levels of cTnI, CK-MB, and LDH were measured. Inflammation, autophagy protein expression, and caspase-1 activity changes were measured at the protein level. Primary cardiomyocytes were used to investigate the direct effect of dapagliflozin on cardiomyocytes and to verify whether they have the same effect as observed in in vivo experiments. Result: A high dose of dapagliflozin significantly reduced infarct size and decreased the serum levels of cTnI, CK-MB, and LDH. Dapagliflozin also reduced serum levels of IL-1β, reduced expression of myocardial inflammation-related proteins, and inhibited cardiac caspase-1 activity. The treatment restored autophagy flux and promoted the degradation of autophagosomes. Relief of inflammation relied on autophagosome phagocytosis of NLRP3 and autophagosome clearance after lysosome improvement. 10 μM dapagliflozin reduced intracellular Ca²⁺ and Na⁺ in primary cardiomyocytes, and increasing NHE1 and NCX expression mitigated dapagliflozin effects on autophagy. Conclusion: Dapagliflozin protects against myocardial ischemia/reperfusion injury independently of its hypoglycemic effect. High-dose dapagliflozin pretreatment might limit NLRP3 inflammasome activation and mediate its selective autophagy. Dapagliflozin directly acts on cardiomyocytes through NHE1/NCX.

Dysregulated Epicardial Adipose Tissue as a Risk Factor and Potential Therapeutic Target of Heart Failure with Preserved Ejection Fraction in Diabetes

Cardiovascular (CV) disease and heart failure (HF) are the leading cause of mortality in type 2 diabetes (T2DM), a metabolic disease which represents a fast-growing health challenge worldwide. Specifically, T2DM induces a cluster of systemic metabolic and non-metabolic signaling which may promote myocardium derangements such as inflammation, fibrosis, and myocyte stiffness, which represent the hallmarks of heart failure with preserved ejection fraction (HFpEF). On the other hand, several observational studies have reported that patients with T2DM have an abnormally enlarged and biologically transformed epicardial adipose tissue (EAT) compared with non-diabetic controls. This expanded EAT not only causes a mechanical constriction of the diastolic filling but is also a source of pro-inflammatory mediators capable of causing inflammation, microcirculatory dysfunction and fibrosis of the underlying myocardium, thus impairing the relaxability of the left ventricle and increasing its filling pressure. In addition to representing a potential CV risk factor, emerging evidence shows that EAT may guide the therapeutic decision in diabetic patients as drugs such as metformin, glucagon-like peptide‑1 (GLP-1) receptor agonists and sodium-glucose cotransporter 2 inhibitors (SGLT2-Is), have been associated with attenuation of EAT enlargement.

Empagliflozin Alleviates Left Ventricle Hypertrophy in High-Fat-Fed Mice by Modulating Renin Angiotensin Pathway

Aims. The cardiobenefits of empagliflozin are multidimensional, and some mechanisms are still unclear. The aim of the present study was to evaluate the effect of treatment with empagliflozin on biometric parameters and gene expression in the local cardiac RAS, oxidative stress, and endoplasmic reticulum pathways in a mouse model. Main Methods. Forty male C57BL/6 mice were fed with control (C) or high-fat (HF) diets for 10 weeks. After that, the groups were redistributed according to the treatment with empagliflozin—CE or HFE. The empagliflozin was administered via food for 5 weeks (10 mg/kg/day). We performed biochemical analyses, blood pressure monitoring, oral glucose tolerance test, left ventricle (LV) stereology, RT-qPCR for genes related to classical and counterregulatory local RAS, oxidative stress, and endoplasmic reticulum stress. Key Findings. In comparison to HF, HFE decreased body mass and improved glucose intolerance and insulin resistance. The cardiac parameters were enhanced after treatment as expressed by decrease in plasma cholesterol, plasma uric acid, and systolic blood pressure. In addition, LV analysis showed that empagliflozin reduces cardiomyocyte area and LV thickness. The local RAS had less activity of the classical pathway and positive effects on the counterregulatory pathway. Empagliflozin treatment also decreased oxidative stress and endoplasmic reticulum stress-related genes. Significance. Our results suggests that empagliflozin modulates the local RAS pathway towards alleviation of oxidative stress and ER stress in the LV, which may be a route to its effects on improved cardiac remodeling.

Empagliflozin Induces White Adipocyte Browning and Modulates Mitochondrial Dynamics in KK Cg-Ay/J Mice and Mouse Adipocytes

Background: White adipose tissue (WAT) browning is a promising target for obesity prevention and treatment. Empagliflozin has emerged as an agent with weight-loss potential in clinical and in vivo studies, but the mechanisms underlying its effect are not fully understood. Here, we investigated whether empagliflozin could induce WAT browning and mitochondrial alterations in KK Cg-Ay/J (KKAy) mice, and explored the mechanisms of its effects.

Methods: Eight-week-old male KKAy mice were administered empagliflozin or saline for 8 weeks and compared with control C57BL/6J mice. Mature 3T3-L1 adipocytes were treated in the presence or absence of empagliflozin. Mitochondrial biosynthesis, dynamics, and function were evaluated by gene expression analyses, fluorescence microscopy, and enzymatic assays. The roles of adenosine monophosphate–activated protein kinase (AMPK) and peroxisome proliferator–activated receptor-γ coactivator-1-alpha (PGC-1α) were determined through AICAR (5-Aminoimidazole-4-carboxamide1-β-D-ribofuranoside)/Compound C and RNA interference, respectively.

Results: Empagliflozin substantially reduced the bodyweight of KKAy mice. Mice treated with empagliflozin exhibited elevated cold-induced thermogenesis and higher expression levels of uncoupling protein 1 (UCP1) and other brown adipose tissue signature proteins in epididymal and perirenal WAT, which was an indication of browning in these WAT depots. At the same time, empagliflozin enhanced fusion protein mitofusin 2 (MFN2) expression, while decreasing the levels of the fission marker phosphorylated dynamin-related protein 1 (Ser616) [p-DRP1 (Ser616)] in epididymal and perirenal WAT. Empagliflozin also increased mitochondrial biogenesis and fusion, improved mitochondrial integrity and function, and promoted browning of 3T3-L1 adipocytes. Further, we found that AMPK signaling activity played an indispensable role in empagliflozin-induced browning and mitochondrial biogenesis, and that PGC-1α was required for empagliflozin-induced fusion. Whether empagliflozin activates AMPK by inhibition of SGLT2 or by independent mechanisms remains to be tested.

Conclusion: Our results suggest that empagliflozin is a promising anti-obesity treatment, which can immediately induce WAT browning mitochondrial biogenesis, and regulate mitochondrial dynamics.

Beneficial effects of sodium glucose cotransporter 2 inhibitors on left ventricular mass in patients with diabetes mellitus

BACKGROUND

Sodium glucose cotransporter 2 inhibitor (SGLT2i) has recently been suggested to reduce the risk of cardiovascular events. Left ventricular hypertrophy (LVH) is associated with cardiovascular events. Diabetic macroangiopathy is a crucial complication in patients with diabetes mellitus (DM). This study examined the effect of SGLT2i on LVH in patients with type 2 DM (T2DM).

METHODS

The retrospective cohort study was conducted in consecutive outpatients with T2DM from 2010 to 2020. Left ventricular mass index (LVMI) was used as an indicator of LVH based on echocardiography. The minimum follow-up period was 1 year. After propensity score-matching for clinical profiles, patients who underwent annual echocardiography twice for a routine checkup and took SGLT2i were defined to the SGLT2i group, whereas patients without SGLT2 inhibitors were defined to the non-SGLT2 group. SGLT2i was administered after baseline echocardiography followed by a second examination.

RESULTS

LVMI levels in the SGLT2i group (n = 169) significantly decreased from baseline compared with those in the non-SGLT2i group (n = 169), % changes in LVMI2.7(g/m^2.7 ) in median (interquartile ranges [IQR]) were - 7.7 (-18.7, 2.5) vs -3.6 (-14.3, 5.8), respectively, P = 0.017). In a subgroup analysis, LVMI levels in the patients who had LVH in the SGLT2i group more significantly decreased than those without LVH, % changes in LVMI2.7(g/m^2.7 ) in median (IQR) were -13.5 (-22.1, -2.4) vs -2.8 (-12.6, 9.8), respectively, P < 0.001).

CONCLUSIONS

SGLT2i treatment was shown to improve LVH in patients with T2DM and may play a pivotal role in the future treatment of diabetic cardiovascular complications.

Overview of Sodium-Glucose Co-transporter 2 (SGLT2) Inhibitors for the Treatment of Non-diabetic Heart Failure Patients

Heart failure (HF) is a clinical syndrome that results from any structural or functional impairment of ventricular filling or ejection of blood, and results in low life quality and expectancy, creating a significant burden on the healthcare system. The pharmacological HF management has remained unchanged for a decade, however, several randomized clinical trials have demonstrated the potential clinical benefits of sodium-glucose cotransporter-2 inhibitors, an antidiabetic agent, by reducing the rate of hospitalizations for HF, cardiovascular death, and all-cause death. The cardioprotective effects are characterized by reduction of inflammatory, metabolic and ionic dyshomeostasis despite the diabetic status. Since the United States Food and Drug Administration (FDA) approval in May 2020, SGLT2 inhibitors have been used mostly in heart failure with reduced ejection fraction (HFrEF). In this review article, we provide a comprehensive overview of the potential benefits, effectiveness, and safety profile of SGLT2 inhibitors used in HF patients with no history of diabetes mellitus.

Fibrosis of the diabetic heart: Clinical significance, molecular mechanisms, and therapeutic opportunities

In patients with diabetes, myocardial fibrosis may contribute to the pathogenesis of heart failure and arrhythmogenesis, increasing ventricular stiffness and delaying conduction. Diabetic myocardial fibrosis involves effects of hyperglycemia, lipotoxicity and insulin resistance on cardiac fibroblasts, directly resulting in increased matrix secretion, and activation of paracrine signaling in cardiomyocytes, immune and vascular cells, that release fibroblast-activating mediators. Neurohumoral pathways, cytokines, growth factors, oxidative stress, advanced glycation end-products (AGEs), and matricellular proteins have been implicated in diabetic fibrosis; however, the molecular links between the metabolic perturbations and activation of a fibrogenic program remain poorly understood. Although existing therapies using glucose- and lipid-lowering agents and neurohumoral inhibition may act in part by attenuating myocardial collagen deposition, specific therapies targeting the fibrotic response are lacking. This review manuscript discusses the clinical significance, molecular mechanisms and cell biology of diabetic cardiac fibrosis and proposes therapeutic targets that may attenuate the fibrotic response, preventing heart failure progression.

Effects of a 12-Month Treatment with Glucagon-like Peptide-1 Receptor Agonists, Sodium-Glucose Cotransporter-2 Inhibitors, and Their Combination on Oxidant and Antioxidant Biomarkers in Patients with Type 2 Diabetes

Imbalance between oxidative stress burden and antioxidant capacity is implicated in the course of atherosclerosis among type 2 diabetic patients. We addressed the effects of insulin, glucagon-like peptide-1 receptor agonists (GLP1-RA), sodium-glucose cotransporter-2 inhibitors (SGLT-2i), and their combination on levels of oxidant and antioxidant biomarkers. We recruited a total of 160 type 2 diabetics, who received insulin (n = 40), liraglutide (n = 40), empagliflozin (n = 40), or their combination (GLP-1RA+SGLT-2i) (n = 40). We measured at baseline, at 4 and at 12 months of treatment: (a) Thiobarbituric Acid Reactive Substances (TBARS), (b) Malondialdehyde (MDA), (c) Reducing Power (RP), (d) 2,2¢-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid) radical (ABTS) and (e) Total Antioxidant Capacity TAC). Dual treatment resulted in significant improvement of TBARS, MDA, and ABTS at four months compared with the other groups (p < 0.05 for all comparisons). At twelve months, all participants improved TBARS, MDA, and ABTS (p < 0.05). At 12 months, GLP1-RA and GLP-1RA+SGLT2-i provided a greater reduction of TBARS (−8.76% and −9.83%) compared with insulin or SGLT2i (−0.5% and 3.22%), (p < 0.05). GLP1-RA and GLP-1RA+SGLT-2i showed a greater reduction of MDA (−30.15% and −31.44%) compared with insulin or SGLT2i (4.72% and −3.74%), (p < 0.05). SGLT2i and GLP-1RA+SGLT2-i showed increase of ABTS (12.87% and 14.13%) compared with insulin or GLP1-RA (2.44% and −3.44%), (p < 0.05). Only combined treatment resulted in increase of TAC compared with the other groups after 12 months of treatment (p < 0.05).12-month treatment with GLP1-RA and SGLT2i resulted in reduction of biomarkers responsible for oxidative modifications and increase of antioxidant biomarker, respectively. The combination treatment was superior and additive to each separate agent and also the beneficial effects appeared earlier.

Bexagliflozin for type 2 diabetes: an overview of the data

Introduction: Sodium-glucose cotransporter-2 (SGLT2) inhibitors are a relatively novel glucose-lowering drugs (GLDs) which additionally promote weight loss and blood pressure reduction among other beneficial effects.Areas covered: This review reflects on the extra-glycemic effects of SGLT2 inhibitors and their impact on important clinical endpoints, and provides an overview of data relating to a newer member of the SGLT2 inhibitor class, bexagliflozin.Expert opinion: SGLT2 inhibitors, while consolidating glycemic control as adjunctive therapy, indisputably affect cardio-renal benefits in the T2D population which is prevalently afflicted by heightened cardiovascular risk and a disproportionately increased incidence of unfavorable cardiovascular and renal outcomes. The data from landmark trials demonstrate that beneficial effects of SGLT2 inhibitors extend to non-diabetic patients with chronic kidney disease (CKD) and/or heart failure with reduced ejection fraction (HFrEF). Preliminary findings from the BEST trial suggest that Bexagliflozin's effects reflect those of other licensed drugs in its class. Bexagliflozin has also been shown to be safe and effective in patients with diabetes and CKD stage 3b. If and when approved, it presents physicians with the prospect of an additional therapeutic option in managing patients with type 2 diabetes mellitus (T2D), and conceivably also, nondiabetic patients with established CKD and/or HFrEF.

The Na/K-ATPase Signaling and SGLT2 Inhibitor-Mediated Cardiorenal Protection: A Crossed Road?

In different large-scale clinic outcome trials, sodium (Na⁺)/glucose co-transporter 2 (SGLT2) inhibitors showed profound cardiac- and renal-protective effects, making them revolutionary treatments for heart failure and kidney disease. Different theories are proposed according to the emerging protective effects other than the original purpose of glucose-lowering in diabetic patients. As the ATP-dependent primary ion transporter providing the Na⁺ gradient to drive other Na⁺-dependent transporters, the possible role of the sodium–potassium adenosine triphosphatase (Na/K-ATPase) as the primary ion transporter and its signaling function is not explored.

Effects of Sodium-Glucose Linked Transporter 2 Inhibition With Ertugliflozin on Mitochondrial Function, Energetics, and Metabolic Gene Expression in the Presence and Absence of Diabetes Mellitus in Mice

Background Inhibitors of the sodium-glucose linked transporter 2 improve cardiovascular outcomes in patients with or without type 2 diabetes mellitus, but the effects on cardiac energetics and mitochondrial function are unknown. We assessed the effects of sodium-glucose linked transporter 2 inhibition on mitochondrial function, high-energy phosphates, and genes encoding mitochondrial proteins in hearts of mice with and without diet-induced diabetic cardiomyopathy. Methods and Results Mice fed a control diet or a high-fat, high-sucrose diet received ertugliflozin mixed with the diet (0.5 mg/g of diet) for 4 months. Isolated mitochondria were assessed for functional capacity. High-energy phosphates were assessed by 31P nuclear magnetic resonance spectroscopy concurrently with contractile performance in isolated beating hearts. The high-fat, high-sucrose diet caused myocardial hypertrophy, diastolic dysfunction, mitochondrial dysfunction, and impaired energetic response, all of which were prevented by ertugliflozin. With both diets, ertugliflozin caused supernormalization of contractile reserve, as measured by rate×pressure product at high work demand. Likewise, the myocardial gene sets most enriched by ertugliflozin were for oxidative phosphorylation and fatty acid metabolism, both of which were enriched independent of diet. Conclusions Ertugliflozin not only prevented high-fat, high-sucrose-induced pathological cardiac remodeling, but improved contractile reserve and induced the expression of oxidative phosphorylation and fatty acid metabolism gene sets independent of diabetic status. These effects of sodium-glucose linked transporter 2 inhibition on cardiac energetics and metabolism may contribute to improved structure and function in cardiac diseases associated with mitochondrial dysfunction, such as heart failure.

Sodium-Glucose Co-Transporter 2 Inhibitors and Insights from Biomarker Measurement in Heart Failure Patients

BACKGROUND

Several large trials have demonstrated cardiac benefits in patients with and without established cardiovascular disease treated with sodium-glucose co-transporter 2 inhibitors (SGLT2i). Most recently, in patients with heart failure with reduced ejection fraction (HFrEF), the risk of worsening HF or cardiovascular death was lower among those who received dapagliflozin than among those who received placebo, regardless of the presence or absence of diabetes. Biomarkers may provide insight into understanding the mechanism of cardiovascular benefit observed in patients receiving SLGT2i. Several mechanisms have been proposed, including improvement in ventricular unloading due to the natriuretic effects, afterload reduction via reduction in blood pressure and improvement in vascular function, improvement in cardiac metabolism and bioenergetics, and reduction in cardiac fibrosis and necrosis, among others.

CONTENT

We discuss several animal and human studies on the effect of SGLT2i on various biomarkers. Modest reduction or blunting of rise over time in concentrations of atrial natriuretic peptide, B-type natriuretic peptide, and N-terminal pro B-type natriuretic peptide and reduction in high-sensitivity troponin has been observed in patients receiving SLGT2i. Concentrations of biomarkers such as sST2 and galectin-3 have been unchanged whereas inflammatory markers such as fibronectin 1, interleukin-6, matrix metalloproteinase 7, and tumor necrosis factor-1 are decreased with SGLT2i therapy.

SUMMARY

The effect of SLGT2i on various circulating biomarkers allows insight into the understanding of mechanisms of cardiovascular benefits with SGLT2i use. Further studies are needed to understand such mechanisms and to understand how biomarkers can be used for risk prediction and personalization of care in patients receiving SLGT2i.

Study rationale and design of a study of EMPAgliflozin's effects in patients with type 2 diabetes mellitus and Coronary ARtery disease: the EMPA-CARD randomized controlled trial

Background

Recent trials have revealed that sodium-glucose co-transporter 2 inhibitors (SGLT2-i) are effective against hyperglycemia and also reduce micro- and macro-vascular complications in patients with type 2 diabetes mellitus (T2DM). Most of the beneficial cardiovascular effects have been investigated in patients with heart failure and coronary artery disease (CAD). Yet, few human studies have been conducted to investigate the molecular mechanisms underlying these clinically beneficial effects in patients with CAD. Accordingly, the EMPA-CARD trial was designed to focus on the molecular effects of empagliflozin in patients with T2DM and CAD.

Methods

In this multicenter, triple-blind randomized controlled trial, patients with documented known T2DM and CAD will be recruited. They will be randomized on a 1:1 ratio and assigned into two groups of empagliflozin 10 mg/daily and placebo. The primary endpoint is the effect of empagliflozin on changes of plasma interleukin 6 (IL-6) after 26 weeks of treatment. The secondary endpoints will consist of changes in other inflammatory biomarkers (Interleukin 1-beta and high-sensitive C-reactive protein), markers of oxidative stress, platelet function, and glycemic status.

Discussion

The EMPA-CARD trial mainly tests the hypothesis that SGLT2 inhibition by empagliflozin may improve inflammatory status measured as reduction in inflammatory biomarkers in patients with T2DM and CAD. The results will provide information about the underlying mechanisms of SGLT2 inhibition that mediate the beneficial effects of this medication on clinical outcomes.

Trial registration

Iranian Registry of Clinical Trials. www.IRCT.ir, Identifier: IRCT20190412043247N2. Registration Date: 6/13/2020. Registration timing: prospective.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02131-1.

Mechanisms and Therapeutic Prospects of Diabetic Cardiomyopathy Through the Inflammatory Response

The incidence of heart failure (HF) continues to increase rapidly in patients with diabetes. It is marked by myocardial remodeling, including fibrosis, hypertrophy, and cell death, leading to diastolic dysfunction with or without systolic dysfunction. Diabetic cardiomyopathy (DCM) is a distinct myocardial disease in the absence of coronary artery disease. DCM is partially induced by chronic systemic inflammation, underpinned by a hostile environment due to hyperglycemia, hyperlipidemia, hyperinsulinemia, and insulin resistance. The detrimental role of leukocytes, cytokines, and chemokines is evident in the diabetic heart, yet the precise role of inflammation as a cause or consequence of DCM remains incompletely understood. Here, we provide a concise review of the inflammatory signaling mechanisms contributing to the clinical complications of diabetes-associated HF. Overall, the impact of inflammation on the onset and development of DCM suggests the potential benefits of targeting inflammatory cascades to prevent DCM. This review is tailored to outline the known effects of the current anti-diabetic drugs, anti-inflammatory therapies, and natural compounds on inflammation, which mitigate HF progression in diabetic populations.

Obesity and Heart Failure with Preserved Ejection Fraction

Obese heart failure with preserved ejection fraction (HFpEF) is a distinct HFpEF phenotype. Sodium retention, high circulating neurohormone levels, alterations in energy substrate metabolism, group 3 pulmonary hypertension, pericardial restraint, and systemic inflammation are central pathophysiologic mechanisms. Confirming the diagnosis may be challenging and high suspicion is required. Reduction of visceral adipose tissue, via caloric restriction and/or bariatric surgery, may improve outcomes in obese HFpEF patients. Furthermore, mineralocorticoid receptor inhibition, neprilysin inhibition, and sodium-glucose cotransporter 2 inhibition can ameliorate the effects of adiposity on the cardiovascular system, allowing for promising new treatment targets for the obese HFpEF phenotype.

Empagliflozin alleviates ethanol-induced cardiomyocyte injury through inhibition of mitochondrial apoptosis via a SIRT1/PTEN/Akt pathway

Ethanol-induced myocardial injury involves multiple pathophysiological processes including apoptosis. Empagliflozin (EMPA), is a novel hypoglycaemic drug which possesses multiple pharmacologically relevant protective effects, including anti-apoptotic, anti-inflammatory and antioxidant effects. However, whether EMPA treatment has a protective effect on ethanol-induced myocardial injury has not been assessed, to the best of our knowledge. Therefore, the aim of this study was to determine the effect of EMPA treatment on ethanol-induced myocardial injury and the underlying mechanism. An ethanol-induced myocardial injury model was established by culturing H9c2 cells treated with 200 mmol/L ethanol for 24 hours, and additional groups of ethanol treated cells were also treated with EMPA with or without SIRT1 inhibitors prior to ethanol treatment. Cell viability and apoptosis were assessed using a CCK-8 assay and flow cytometry, respectively. The expression of apoptosis-related proteins was assessed using western blotting. The results showed that EMPA pretreatment resulted in increased cell viability and a decrease in LDH activity. Moreover, EMPA pretreatment significantly reduced apoptosis of cardiomyocytes, and reduced the expression of cleaved caspase 3. Furthermore, EMPA increased the expression of SIRT1, increased the phosphorylation levels of Akt, and reduced the expression of PTEN. EMPA also reduced ethanol-induced mitochondrial apoptosis, increasing the Bcl-2/Bax ratio and the mitochondrial membrane potential. However, the cardioprotective effects of EMPA were abrogated when cells were pretreated with a SIRT1 inhibitor. In conclusion, EMPA can alleviate ethanol-induced myocardial injury by inhibiting mitochondrial apoptosis via the SIRT1/PTEN/Akt pathway. Therefore, EMPA may be a novel target for treatment of ethanol-induced myocardial injury.

Empagliflozin therapy and insulin resistance-associated disorders: effects and promises beyond a diabetic state

Empagliflozin is a SGLT2 inhibitor that has shown remarkable cardiovascular and renal activities in patients with type 2 diabetes (T2D). Preclinical and clinical studies of empagliflozin in T2D population have demonstrated significant improvements in body weight, waist circumference, insulin sensitivity, and blood pressure – effects beyond its antihyperglycaemic control. Moreover, several studies suggested that this drug possesses significant anti-inflammatory and antioxidative stress properties. This paper explores extensively the main preclinical and clinical evidence of empagliflozin administration in insulin resistance-related disorders beyond a diabetic state. It also discusses its future perspectives, as a therapeutic approach, in this high cardiovascular-risk population.

Protective effects of dapagliflozin against oxidative stress-induced cell injury in human proximal tubular cells

Elevated reactive oxygen species (ROS) in type 2 diabetes cause cellular damage in many organs. Recently, the new class of glucose-lowering agents, SGLT-2 inhibitors, have been shown to reduce the risk of developing diabetic complications; however, the mechanisms of such beneficial effect are largely unknown. Here we aimed to investigate the effects of dapagliflozin on cell proliferation and cell death under oxidative stress conditions and explore its underlying mechanisms. Human proximal tubular cells (HK-2) were used. Cell growth and death were monitored by cell counting, water-soluble tetrazolium-1 (WST-1) and lactate dehydrogenase (LDH) assays, and flow cytometry. The cytosolic and mitochondrial (ROS) production was measured using fluorescent probes (H2DCFDA and MitoSOX) under normal and oxidative stress conditions mimicked by addition of H₂O₂. Intracellular Ca²⁺ dynamics was monitored by FlexStation 3 using cell-permeable Ca²⁺ dye Fura-PE3/AM. Dapagliflozin (0.1–10 μM) had no effect on HK-2 cell proliferation under normal conditions, but an inhibitory effect was seen at an extreme high concentration (100 μM). However, dapagliflozin at 0.1 to 5 μM showed remarkable protective effects against H₂O₂-induced cell injury via increasing the viable cell number at phase G0/G1. The elevated cytosolic and mitochondrial ROS under oxidative stress was significantly decreased by dapagliflozin. Dapagliflozin increased the basal intracellular [Ca²⁺]_i in proximal tubular cells, but did not affect calcium release from endoplasmic reticulum and store-operated Ca²⁺ entry. The H₂O₂-sensitive TRPM2 channel seemed to be involved in the Ca²⁺ dynamics regulated by dapagliflozin. However, dapagliflozin had no direct effects on ORAI1, ORAI3, TRPC4 and TRPC5 channels. Our results suggest that dapagliflozin shows anti-oxidative properties by reducing cytosolic and mitochondrial ROS production and altering Ca²⁺ dynamics, and thus exerts its protective effects against cell damage under oxidative stress environment.

SGLT2 inhibitors: a focus on cardiac benefits and potential mechanisms

This paper highlights the cardioprotective potential of sodium-glucose cotransporter 2 inhibitors (SLGT2i), as well as several most discussed mechanisms responsible for their cardioprotection. Cardiovascular diseases are considered a primary cause of death in nearly 80% of type 2 diabetes mellitus (T2DM) patients, with a 2-4-fold greater incidence of heart failure (HF) among diabetics. As novel hypoglycemics, SGLT2i showed exceptional cardiovascular benefits, reflected through robust reductions of cardiovascular mortality and hospitalization for HF in T2DM patients. Recently, those effects have been reported even in patients with HF and reduced ejection fraction irrespectively of diabetic status, suggesting that cardioprotective effects of SGLT2i are driven independently of their hypoglycemic actions. SGLT2i exerted hemodynamic and metabolic effects, partially driven by natriuresis and osmotic diuresis. However, those systemic effects are modest, and therefore cannot be completely related to the cardiac benefits of these agents in T2DM patients. Hence, increased circulating ketone levels during SGLT2i administration have brought out another hypothesis of a cardiac metabolic switch. Moreover, SGLT2i influence ion homeostasis and exert anti-inflammatory and antifibrotic effects. Their enviable influence on oxidative stress markers, as well as anti- and pro-apoptotic factors, have also been reported. However, since the main mechanistical contributor of their cardioprotection has not been elucidated yet, a joint action of systemic and molecular mechanisms has been suggested. In the light of ongoing trials evaluating the effects of SGLT2i in patients with HF and preserved ejection fraction, a new chapter of beneficial SGLT2i mechanisms is expected, which might resolve their main underlying action.

SGLT2 Inhibitors: A Novel Player in the Treatment and Prevention of Diabetic Cardiomyopathy

Diabetic cardiomyopathy (DCM) characterized by diastolic and systolic dysfunction independently of hypertension and coronary heart disease, eventually develops into heart failure, which is strongly linked to a high prevalence of mortality in people with diabetes mellitus (DM). Sodium-glucose cotransporter type2 inhibitors (SGLT2Is) are a novel type of hypoglycemic agent in increasing urinary glucose and sodium excretion. Excitingly, the EMPA-REG clinical trial proved that empagliflozin significantly reduced the relative risk of cardiovascular (CV) death and hospitalization for heart failure (HHF) in patients with type 2 DM (T2DM) plus CV disease (CVD). The EMPRISE trial showed that empagliflozin decreased the risk of HHF in T2DM patients with and without a CVD history in routine care. These beneficial effects of SGLT2Is could not be entirely attributed to glucose-lowering or natriuretic action. There could be potential direct mechanisms of SGLT2Is in cardioprotection. Recent studies have shown the effects of SGLT2Is on cardiac iron homeostasis, mitochondrial function, anti-inflammation, anti-fibrosis, antioxidative stress, and renin-angiotensin-aldosterone system activity, as well as GlcNAcylation in the heart. This article reviews the current literature on the effects of SGLT2Is on DCM in preclinical studies. Possible molecular mechanisms regarding potential benefits of SGLT2Is for DCM are highlighted, with the purpose of providing a novel strategy for preventing DCM.