The Effects of Sodium-Glucose Cotransporter 2 Inhibitors on Sympathetic Nervous Activity

Effects of oral antidiabetic agents on the renin-angiotensin-aldosterone system

BACKGROUND

The renin-angiotensin-aldosterone system (RAAS) is a vital endocrine system that plays a crucial role in maintaining homeostasis. However, excessive activation of the RAAS can contribute to the pathogenesis of certain diseases. Prolonged hyperglycemia leads to overactivation of the RAAS through the production of inflammatory factors and other mechanisms, ultimately resulting in diabetic complications. Oral antidiabetic agents are the cornerstone of diabetes treatment, and the effects of oral antidiabetic agents on the RAAS have not been clearly summarized.

OBJECTIVE

To review the effects of various types of oral antidiabetic agents on the components of the RAAS.

RESULTS

Sodium-glucose cotransporter inhibitors (SGLT2i) inhibit glucose and sodium reabsorption, which increases the flow of Na+ to the macula densa, thereby inhibiting tubuloglomerular feedback (TGF) and subsequently decreasing renin production. GLP-1 receptor agonists (GLP-1RA) and dipeptidyl peptidase-4 inhibitors (DPP-4i) can directly inhibit angiotensin II (Ang II) or indirectly suppress it by modulating TGF. These agents also affect Ang II type 1 receptors (AT1R) and Ang II type 2 receptors (AT2R) to mitigate Ang II and can indirectly interact with Ang II through Na+/H+ exchanger isotope 3 (NHE3). Thiazolidinediones (TZDs), as PPAR-γ agonists, can enhance the expression of the renin gene, inhibit the production of angiotensin-converting enzyme (ACE), regulate the levels of AT1R and AT2R, and decrease aldosterone production. Metformin also inhibits the production of renin and aldosterone in patients with polycystic ovary syndrome (PCOS).

CONCLUSIONS

These oral agents, which exhibit diverse effects on the components of the RAAS, modulate the activity of these components to exert antihypertensive, anti-inflammatory, cardioprotective, and renoprotective effects, thereby offering several beneficial outcomes in the management of diabetes.

Sodium-glucose cotransporter-2 inhibitor use in type 2 diabetes mellitus is associated with a lower rate of atrial arrhythmias in a hospitalized real-world population

Background

Sodium-glucose cotransporter-2 inhibitors (SGLT2is) have been associated with lower rates of cardiac arrhythmias in post hoc analyses. The real-world effect on cardiac arrhythmias is incompletely defined.

Objective

The purpose of this study was to determine the effects of SGLT2i on cardiac arrhythmias in a real-world, hospitalized population.

Methods

A retrospective cohort study was performed in South Australia, Australia. Patients (n = 882) with type 2 diabetes mellitus (T2DM) on oral diabetic therapy (33.6% females, median age 62.3 years) who received SGLT2i (for T2DM) were identified through public hospital admissions from 2011-2019. Patients were matched with 3282 contemporaneous controls with T2DM who did not receive SGLT2i. Baseline characteristics were adjusted using inverse probability treatment weighting. The primary outcome was incidence of atrial arrhythmias. Secondary outcomes included incidence of ventricular arrhythmias and cardiac arrest at 2 years.

Results

All-cause mortality was higher in the SGLT2i group (hazard ratio [HR] 2.02, 95% confidence interval [CI] 1.55-2.63, P <.001) despite propensity matching, highlighting the greater unmeasured comorbidity burden of the SGLT2i-treated group. Despite this, SGLT2i treatment was associated with fewer atrial arrhythmias (HR 0.17, 95% CI 0.07-0.41, P <.001) at 2 years. The relationship between SGLT2i use and ventricular arrhythmias (HR 0.25, 95% CI 0.06-1.03, P = .055) and cardiac arrest (HR 0.82, 95% CI 0.20-3.45, P = .796) did not reach statistical significance.

Conclusion

In this real-world, comorbid inpatient cohort, SGLT2i treatment was associated with a lower incidence of atrial arrhythmias. Prospective randomized trials evaluating SGLT2i as specific atrial fibrillation pharmacotherapy are underway.

Empagliflozin ameliorates ventricular arrhythmias by inhibiting sympathetic remodeling via nerve growth factor/tyrosine kinase receptor A pathway inhibition

BACKGROUND AND AIMS

Sodium-glucose cotransporter 2 inhibitors (SGLT2is) can ameliorate arrhythmias; however, the mechanisms underlying their antiarrhythmic effect remain unclear. Therefore, we aimed to test the hypothesis that the SGLT2i empagliflozin (EMPA) ameliorates ventricular arrhythmias caused by myocardial infarction (MI) by inhibiting sympathetic remodeling.

METHODS

Male nondiabetic Sprague-Dawley rats were divided into Sham ( n  = 10), MI ( n  = 13), low-EMPA (10 mg/kg/day; n  = 13), and high-EMPA (30 mg/kg/day; n  = 13) groups. Except for the Sham group, MI models were established by ligation of the left anterior descending coronary artery. After 4 weeks, the hearts were removed. Echocardiography, electrical stimulation, hematoxylin-eosin staining and Masson's staining, Western blotting, immunohistochemistry (IHC), and ELISA were performed.

RESULTS

Except for left ventricular posterior wall thickness (LVPWT), EMPA treatment significantly ameliorated the left ventricular anterior wall thickness (LVAWT), interventricular septum thickness (IVST), left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), and left ventricular ejection fraction (LVEF) in MI rats; there was no statistical difference between the low-EMPA and high-EMPA groups. The threshold for ventricular fibrillation induction and myocardial fibrosis was significantly ameliorated in EMPA-treated rats, and there was no statistical difference between the high-EMPA and low-EMPA groups. EMPA decreased the expression of nerve growth factor (NGF), tyrosine kinase receptor A (TrkA), tyrosine hydroxylase, and growth-associated protein 43 (GAP43) in the left ventricular infarction margin myocardium of MI rats, especially in the high-EMPA group, with a statistically significant difference between the high-EMPA and low-EMPA groups. High-EMPA significantly decreased noradrenaline (NE) levels in the blood of MI rats; however, there was no statistical difference between the low-EMPA and MI groups.

CONCLUSION

EMPA ameliorated the occurrence of ventricular arrhythmias in MI rats, which may be related to a reduction in sympathetic activity, inhibition of the NGF/TrkA pathway, inhibition of sympathetic remodeling, and improvement in cardiac function and cardiac structural remodeling.

SGLT2 Inhibitors and Kidney Protection: Mechanisms Beyond Tubuloglomerular Feedback

Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce the risk for kidney failure and are a key component of guideline-directed therapy for CKD. While SGLT2 inhibitors' ability to activate tubuloglomerular feedback and reduce hyperfiltration-mediated kidney injury is considered to be the central mechanism for kidney protection, recent data from experimental studies raise questions on the primacy of this mechanism. This review examines SGLT2 inhibitors' role in tubuloglomerular feedback and summarizes emerging evidence on following of SGLT2 inhibitors' other putative mechanisms for kidney protection: optimization of kidney's energy substrate utilization and delivery, regulation of autophagy and maintenance of cellular homeostasis, attenuation of sympathetic hyperactivity, and improvement in vascular health and microvascular function. It is imperative to examine the effect of SGLT2 inhibition on these different physiologic processes to help our understanding of mechanisms underpinning kidney protection with this important class of drugs.

Sodium-Glucose Cotransporter Protein 2 Inhibitors: Novel Application for the Treatment of Obesity-Associated Hypertension

Obesity is becoming increasingly prevalent in China and worldwide and is closely related to the development of hypertension. The pathophysiology of obesity-associated hypertension is complex, including an overactive sympathetic nervous system (SNS), activation of the renin-angiotensin-aldosterone system (RAAS), insulin resistance, hyperleptinemia, renal dysfunction, inflammatory responses, and endothelial function, which complicates treatment. Sodium-glucose cotransporter protein 2 (SGLT-2) inhibitors, novel hypoglycemic agents, have been shown to reduce body weight and blood pressure and may serve as potential novel agents for the treatment of obesity-associated hypertension. This review discusses the beneficial mechanisms of SGLT-2 inhibitors for the treatment of obesity-associated hypertension. SGLT-2 inhibitors can inhibit SNS activity, reduce RAAS activation, ameliorate insulin resistance, reduce leptin secretion, improve renal function, and inhibit inflammatory responses. SGLT-2 inhibitors can, therefore, simultaneously target multiple mechanisms of obesity-associated hypertension and may serve as an effective treatment for obesity-associated hypertension.

Antianginal effects of empagliflozin in patients with type 2 diabetes and refractory angina; a randomized, double-blind placebo-controlled trial (EMPT-ANGINA Trial)

INTRODUCTION

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are emerging antidiabetic agents with various potential cardiovascular benefits. The EMPT-ANGINA trial examined the effect of empagliflozin on the angina burden in those with concurrent type 2 diabetes mellitus (T2DM) and refractory angina (RA).

METHOD

In this 8-week, double-blind, randomized, placebo-controlled trial, 75 patients with T2DM and RA were randomly assigned to one of two groups: empagliflozin (n = 37) and placebo (n = 38). The primary outcome was an improvement in angina, which was assessed by the Seattle Angina Questionnaire (SAQ). The secondary outcomes of this study included alterations in the SAQ domains and exercise test components.

RESULTS

The mean age of individuals in the empagliflozin and placebo groups was 67.46 ± 9.4 and 65.47 ± 7.0 years, respectively (p = .304). Patients who received empagliflozin showed a significant improvement in both the primary endpoint, which was the SAQ Summary Score (192.73 ± 20.70 vs. 224 ± 25.36, p < .001) and the secondary endpoints. Exercise test components, including treadmill exercise duration, time till angina, 1 mm ST-segment depression onset, and heart rate (HR) recovery, were all significantly improved in the empagliflozin group. This positive impact was reached with no clinically significant changes in resting and exertion HR or blood pressure. There were no significant side effects in the empagliflozin group (p = .125).

CONCLUSION

Empagliflozin can be safely added as a metabolic modulator agent to existing antianginal medications in individuals with concurrent T2DM and RA to reduce angina symptoms and enhance exercise capacity with minimal side effects.

Diabetes Mellitus in Acute Coronary Syndrome

The global prevalence of diabetes mellitus (DM) has led to a pandemic, with significant microvascular and macrovascular complications including coronary artery disease (CAD), which worsen clinical outcomes and cardiovascular prognosis. Patients with both acute coronary syndrome (ACS) and DM have worse prognosis and several pathophysiologic mechanisms have been implicated including, insulin resistance, hyperglycemia, endothelial dysfunction, platelet activation and aggregations as well as plaque characteristics and extent of coronary lesions. Therefore, regarding reperfusion strategies in the more complex anatomies coronary artery bypass surgery may be the preferred therapeutic strategy over percutaneous coronary intervention while both hyperglycemia and hypoglycemia should be avoided with closed monitoring of glycemic status during the acute phase of myocardial infraction. However, the best treatment strategy remains undefined. Non-insulin therapies, due to the low risk of hypoglycemia concurrently with the multifactorial CV protective effects, may be proved to be the best treatment option in the future. Nevertheless, evidence for the beneficial effects of glucagon like peptide-1 receptor agonists, dipeptidyl-peptidase 4 inhibitors and sodium glycose cotransporter 2 inhibitors, despite accumulating, is not robust and future randomized control trials may provide more definitive data.

Sodium-glucose cotransporter type 2 inhibitors and cardiac arrhythmias

The introduction of sodium-glucose cotransporter 2 (SGLT2) inhibitors as a new and effective class of therapeutic agents for type 2 diabetes (T2D) preventing the reabsorption of glucose in the kidneys and thus facilitating glucose excretion in the urine, but also as agents with cardiovascular benefits, particularly in patients with heart failure (HF), regardless of the diabetic status, has ushered in a new era in treating patients with T2D and/or HF. In addition, data have recently emerged indicating an antiarrhythmic effect of the SGLT2 inhibitors in patients with and without diabetes. Prospective studies, randomized controlled trials and meta-analyses have provided robust evidence for a protective and beneficial effect of these agents against atrial fibrillation, ventricular arrhythmias and sudden cardiac death. The antiarrhythmic mechanisms involved include reverse atrial and ventricular remodeling, amelioration of mitochondrial function, reduction of hypoglycemic episodes with their attendant arrhythmogenic effects, attenuated sympathetic nervous system activity, regulation of sodium and calcium homeostasis, and suppression of prolonged ventricular repolarization. These new data on antiarrhythmic actions of SGLT2 inhibitors are herein reviewed, potential mechanisms involved are discussed and pictorially illustrated, and treatment results on specific arrhythmias are described and tabulated.

Role and mechanisms of SGLT-2 inhibitors in the treatment of diabetic kidney disease

Diabetic kidney disease (DKD) is a chronic inflammatory condition that affects approximately 20-40% of individuals with diabetes. Sodium-glucose co-transporter 2 (SGLT-2) inhibitors, emerging as novel hypoglycemic agents, have demonstrated significant cardiorenal protective effects in patients with DKD. Initially, it was believed that the efficacy of SGLT-2 inhibitors declined as the estimated glomerular filtration rate (eGFR) decreased, which led to their preferential use in DKD patients at G1-G3 stages. However, recent findings from the DAPA-CKD and EMPA-KIDNEY studies have revealed equally beneficial cardiorenal effects of SGLT-2 inhibitors in individuals at stage G4 DKD, although the underlying mechanism behind this phenomenon remains unclear. In this comprehensive analysis, we provide a systematic review of the mechanisms and functioning of SGLT-2 inhibitors, potential renal protection mechanisms, and the therapeutic efficacy and safety of SGLT-2 inhibitors in kidney diseases, with a particular focus on stage G4 DKD. Gaining a deeper understanding of the renal protective effect of SGLT-2 inhibitors and their underlying mechanisms is highly significance for the successful utilization of these inhibitors in the treatment of diverse kidney disorders.

Effects of SGLT2 inhibitor administration on blood glucose level and body weight in type 1 diabetes rat model

The prevalence of diabetes worldwide is increasing and 629 million people are projected to have diabetes by 2045, and the most significant burden of the disease being concentrated in low- and middle-income countries (LMICs). Type 2 diabetes is mainly treated with insulin adjunctive therapies such as metformin to improve insulin sensitivity and sodium-glucose co-transporter 2 (SGLT2) inhibitors to lower blood glucose levels. However, there was limited study on the application of SGLT2 inhibitors on type 1 diabetes, particularly empagliflozin. Therefore, this study aimed to determine the effect of SGLT2 inhibitors on blood glucose levels and body weights in a rat model of type 1 diabetes. To mimic type 1 diabetes, the rats were injected with streptozotocin 60 mg intra-peritoneally. Twenty-four rat models were randomly divided into four groups: normal rat group (negative control), untreated diabetic rat group (positive control), type 1 diabetic rats treated with metformin, and type 1 diabetic rats treated with empagliflozin. Blood glucose levels and body weight were recorded before and after induced with streptozotocin and on weeks 4, 6, 8 and 10 of the treatment with anti-diabetic drugs. This study found that the blood glucose levels before and after treatment significantly decreased in all groups (p<0.05), except in the negative control group. Similar results were observed in body weight of the rats, which all groups experienced weight loss, except the negative control. These results suggested that apart from being used in type 2 diabetes, SGLT2 inhibitors may also be used as a treatment for type 1 diabetes.

Autonomic control of ventricular function in health and disease: current state of the art

PURPOSE

Cardiac autonomic dysfunction is one of the main pillars of cardiovascular pathophysiology. The purpose of this review is to provide an overview of the current state of the art on the pathological remodeling that occurs within the autonomic nervous system with cardiac injury and available neuromodulatory therapies for autonomic dysfunction in heart failure.

METHODS

Data from peer-reviewed publications on autonomic function in health and after cardiac injury are reviewed. The role of and evidence behind various neuromodulatory therapies both in preclinical investigation and in-use in clinical practice are summarized.

RESULTS

A harmonic interplay between the heart and the autonomic nervous system exists at multiple levels of the neuraxis. This interplay becomes disrupted in the setting of cardiovascular disease, resulting in pathological changes at multiple levels, from subcellular cardiac signaling of neurotransmitters to extra-cardiac, extra-thoracic remodeling. The subsequent detrimental cycle of sympathovagal imbalance, characterized by sympathoexcitation and parasympathetic withdrawal, predisposes to ventricular arrhythmias, progression of heart failure, and cardiac mortality. Knowledge on the etiology and pathophysiology of this condition has increased exponentially over the past few decades, resulting in a number of different neuromodulatory approaches. However, significant knowledge gaps in both sympathetic and parasympathetic interactions and causal factors that mediate progressive sympathoexcitation and parasympathetic dysfunction remain.

CONCLUSIONS

Although our understanding of autonomic imbalance in cardiovascular diseases has significantly increased, specific, pivotal mediators of this imbalance and the recognition and implementation of available autonomic parameters and neuromodulatory therapies are still lagging.

Cardioprotective Effects of Sodium Glucose Cotransporter 2 Inhibition in Angiotensin II-Dependent Hypertension Are Mediated by the Local Reduction of Sympathetic Activity and Inflammation

The cardioprotective effects of sodium glucose cotrasponter 2 (SGLT2) inhibitors seem to be independent from the effects on glycemic control, through little-known mechanisms. In this study, we investigate whether the cardioprotective effects of empagliflozin, a SGLT2 inhibitor, may be associated with myocardial sympathetic activity and inflammatory cell infiltration in an experimental model of angiotensin II-dependent hypertension. Angiotensin II (Ang II), Ang II plus Empagliflozin, physiological saline, or physiological saline plus empagliflozin were administered to Sprague Dawley rats for two weeks. Blood pressure was measured by plethysmographic method. Myocardial hypertrophy and fibrosis were analysed by histomorphometry, and inflammatory cell infiltration and tyrosine hydroxylase expression, implemented as a marker of sympathetic activity, were evaluated by immunohistochemistry. Ang II increased blood pressure, myocardial hypertrophy, fibrosis, inflammatory infiltrates and tyrosine hydroxylase expression, as compared to the control group. Empagliflozin administration prevented the development of myocardial hypertrophy, fibrosis, inflammatory infiltrates and tyrosine hydroxylase overexpression in Ang II-treated rats, without affecting blood glucose and the Ang II-dependent increase in blood pressure. These data demonstrate that the cardioprotective effects of SGLT2 inhibition in Ang II-dependent hypertension may result from the myocardial reduction of sympathetic activity and inflammation and are independent of the modulation of blood pressure and blood glucose levels.

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.

New Insight in Cardiorenal Syndrome: From Biomarkers to Therapy

Cardiorenal syndrome consists in the coexistence of acute or chronic dysfunction of heart and kidneys resulting in a cascade of feedback mechanisms and causing damage to both organs associated with high morbidity and mortality. In the last few years, different biomarkers have been investigated with the aim to achieve an early and accurate diagnosis of cardiorenal syndrome, to provide a prognostic role and to guide the development of targeted pharmacological and non-pharmacological therapies. In such a context, sodium-glucose cotransporter 2 (SGLT2) inhibitors, recommended as the first-line choice in the management of heart failure, might represent a promising strategy in the management of cardiorenal syndrome due to their efficacy in reducing both cardiac and renal outcomes. In this review, we will discuss the current knowledge on the pathophysiology of cardiorenal syndrome in adults, as well as the utility of biomarkers in cardiac and kidney dysfunction and potential insights into novel therapeutics.

Dapagliflozin attenuates myocardial remodeling in hypertension by activating the circadian rhythm signaling pathway

Sodium-glucose cotransporter 2 inhibitor (SGLT2i) is a new kind of antidiabetic drug which has shown beneficial effects in reducing heart failure-related hospitalization and cardiovascular-related mortality. The mechanisms are complicated. Our study aimed to investigate the effects of dapagliflozin on the myocardium of spontaneously hypertensive rats (SHRs) without heart failure. Wistar-Kyoto rats were used as normal controls. SHRs were randomly divided into the SHR group and the -treated group. After 8 weeks of dapagliflozin treatment, the morphology of heart tissues was examined. The mRNA expression profiles were identified via RNA sequencing (RNA-Seq). Various analysis methods were used to find the differentially expressed genes (DEGs) to predict gene function and coexpression. After dapagliflozin treatment, systolic blood pressure was significantly reduced compared with that in the SHR group. Myocardial remodeling was ameliorated compared with that in the SHR group. After dapagliflozin intervention, 75 DEGs (|log2-fold change | > 0 and Q value < 0.05) were identified in the heart tissues compared to the SHR group. Quantitative real-time PCR analysis confirmed that the expression of the circadian rhythm genes Per3, Bhlhe41, and Nr1d1 was significantly upregulated, while the results were coincident with the RNA-Seq results. Dapagliflozin may effectively inhibit myocardial remodeling and regulate blood pressure. The mechanisms may be related to the activation of the circadian rhythm signaling pathway.

Links between Metabolic Syndrome and Hypertension: The Relationship with the Current Antidiabetic Drugs

Hypertension poses a significant burden in the general population, being responsible for increasing cardiovascular morbidity and mortality, leading to adverse outcomes. Moreover, the association of hypertension with dyslipidaemia, obesity, and insulin resistance, also known as metabolic syndrome, further increases the overall cardiovascular risk of an individual. The complex pathophysiological overlap between the components of the metabolic syndrome may in part explain how novel antidiabetic drugs express pleiotropic effects. Taking into consideration that a significant proportion of patients do not achieve target blood pressure values or glucose levels, more efforts need to be undertaken to increase awareness among patients and physicians. Novel drugs, such as incretin-based therapies and renal glucose reuptake inhibitors, show promising results in decreasing cardiovascular events in patients with metabolic syndrome. The effects of sodium-glucose co-transporter-2 inhibitors are expressed at different levels, including renoprotection through glucosuria, natriuresis and decreased intraglomerular pressure, metabolic effects such as enhanced insulin sensitivity, cardiac protection through decreased myocardial oxidative stress and, to a lesser extent, decreased blood pressure values. These pleiotropic effects are also observed after treatment with glucagon-like peptide-1 receptor agonists, positively influencing the cardiovascular outcomes of patients with metabolic syndrome. The initial combination of the two classes may be the best choice in patients with type 2 diabetes mellitus and multiple cardiovascular risk factors because of their complementary mechanisms of action. In addition, the novel mineralocorticoid receptor antagonists show significant cardio-renal benefits, as well as anti-inflammatory and anti-fibrotic effects. Overall, the key to better control of hypertension in patients with metabolic syndrome is to consider targeting multiple pathogenic mechanisms, using a combination of the different therapeutic agents, as well as drastic lifestyle changes. This article will briefly summarize the association of hypertension with metabolic syndrome, as well as take into account the influence of antidiabetic drugs on blood pressure control.

The Emerging Role of Sodium-glucose Cotransporter 2 Inhibitors in Heart Failure

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are a relatively novel drug class that most cardiologists are becoming familiar with. By contrasting glucose reabsorption in the proximal convoluted tubule of the nephron, SGLT2 inhibition results in glycosuria with improved glycemic control. Although originally introduced as anti-diabetic medications, the cardiovascular effects of SGLT2i have progressively emerged, leading them to become one of the four pillars for the treatment of heart failure with reduced ejection fraction (HFrEF) according to the 2021 guidelines from the European Society of Cardiology. Also, two recent randomized trials have demonstrated SGLT2i as the first compounds with proven prognostic impact in heart failure with preserved ejection fraction (HFpEF), setting a milestone in the treatment for this condition. While the exact pathogenic mechanisms mediating the substantial reduction in cardiovascular death and heart failure (HF) hospitalizations are still controversial, there is growing clinical evidence on the efficacy and safety of SGLT2i in various subsets of patients with HF. As known, heart failure is a complex and heterogeneous clinical syndrome with a magnitude of phenotypes and a variety of underlying hemodynamic and physiological aspects which cannot be fully incorporated into the traditional left ventricular ejection fraction based classification adopted in clinical trials. The aim of this review is to provide an overview of the cardiovascular benefits and indications of SGLT2i across different HF patterns and to highlight current gaps in knowledge that should be addressed by future research.

Effect of SGLT-2 inhibitors on cardiac autonomic function in type 2 diabetes mellitus: a meta-analysis of randomized controlled trials

BACKGROUND

Cardiac autonomic neuropathy (CAN) is a common complication of type 2 diabetes mellitus (T2DM). We sought to determine whether sodium-glucose co-transporter-2 (SGLT-2) inhibitors affect indices of CAN in patients with T2DM.

METHODS

We searched for parallel group or cross-over randomized controlled trials (RCTs) enrolling adult subjects with T2DM, assigned to a SGLT-2 inhibitor versus placebo or active comparator and addressing their effect on CAN. PubMed, Cochrane Library and gray literature sources were searched. We set as primary efficacy outcome the change in the low-frequency-to-high-frequency (LF/HF) ratio. We set as secondary efficacy outcomes: first, the change in the standard deviation of all 5 min mean normal RR intervals and second, the change in the square root of the mean of the sum of the squares of differences between adjacent RR intervals (r-MSSD). Protocol has not been registered at a publicly available repository.

RESULTS

We pooled data from four RCTs in a total of 247 subjects with T2DM. SGLT-2 inhibitor treatment did not have a significant effect on LF/HF ratio (MD = - 0.11, 95% CI - 0.35 to 0.12, I² = 0%, p = 0.36). SGLT-2 inhibitor treatment did not have a significant impact either on SDNN (MD = - 2.83, 95% CI - 7.41 to 1.75, I² = 31%, p = 0.23), or on r-MSSD (MD = - 0.14, 95% CI - 3.52 to 3.25, I² = 46%, p = 0.94). Overall risk of bias was graded as low across the selected RCTs.

CONCLUSION

SGLT-2 inhibitor treatment in patients with T2DM does not seem to provide any significant beneficial effect on CAN indices.

Empagliflozin Improves the MicroRNA Signature of Endothelial Dysfunction in Patients with Heart Failure with Preserved Ejection Fraction and Diabetes

Endothelial dysfunction represents a key mechanism underlying heart failure with preserved ejection fraction (HFpEF), diabetes mellitus (DM), and frailty. However, reliable biomarkers to monitor endothelial dysfunction in these patients are lacking. In this study, we evaluated the expression of a panel of circulating microRNAs (miRs) involved in the regulation of endothelial function in a population of frail older adults with HFpEF and DM treated for 3 months with empagliflozin, metformin, or insulin. We identified a distinctive pattern of miRs that were significantly regulated in HFpEF patients compared to healthy controls and to HFpEF patients treated with the sodium glucose cotransporter 2 (SGLT2) inhibitor empagliflozin. Three miRs were significantly downregulated (miR-126, miR-342-3p, and miR-638) and two were significantly upregulated (miR-21 and miR-92) in HFpEF patients compared to healthy controls. Strikingly, two of these miRs (miR-21 and miR-92) were significantly reduced in HFpEF patients after the 3-month treatment with empagliflozin, whereas no significant differences in the profile of endothelial miRs were detected in patients treated with metformin or insulin. Taken together, our findings demonstrate for the first time that specific circulating miRs involved in the regulation of endothelial function are significantly regulated in frail HFpEF patients with DM and in response to SGLT2 inhibition. SIGNIFICANCE STATEMENT: We have identified a novel microRNA signature functionally involved in the regulation of endothelial function that is significantly regulated in frail patients with HFpEF and diabetes. Moreover, the treatment with the SGLT2 inhibitor empagliflozin caused a modification of some of these microRNAs in a direction that was opposite to what observed in HFpEF patients, indicating a rescue of endothelial function. Our findings are relevant for clinical practice inasmuch as we were able to establish novel biomarkers of disease and response to therapy.

Pleiotropic effect of sodium-glucose cotransporter 2 inhibitors on blood pressure

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have been incorporated as guideline-directed medical therapy for heart failure with reduced ejection fraction. Recent trials clearly established the efficacy of SGLT2 inhibitors on cardiac remodeling while preventing renal function decline in patients with or without diabetes mellitus. Blood pressure reduction during SGLT2 inhibitors use has been proposed through pleiotropic pathways and as a potential contributor that translates to cardiovascular benefits. The mechanisms underlying this decrease in blood pressure are not simply glycemic control. Orchestrating fluid status, modulation of sodium content and renin-angiotensin-activation system, anti-fibrosis and anti-inflammatory effect, ameliorating the characteristics of metabolic syndrome, as well as restoration of circadian rhythm all contributed to the BP lowering effect by SGLT2 inhibitors. Although SGLT2 inhibitors has not been demonstrated as anti-hypertensive agents thus far, their effects on BP alteration are clinically significant. In this review, we revisited the evidence correlating SGLT2 inhibitor use with blood pressure level. Future research directions will focus on the signaling pathway of SGLT2 inhibitors for fluid removal, atherosclerosis, vasoconstriction, and eventually hypertension.

Portal Hypertension in Nonalcoholic Fatty Liver Disease: From Pathogenesis to Clinical Practice

Portal hypertension in nonalcoholic fatty liver disease (NAFLD) mostly occur in cirrhotic stage. However, several experimental and clinical studies showed evidence of portal hypertension in NAFLD without significant or advance fibrosis. This early development of portal hypertension in NAFLD is associated with liver sinusoidal contraction by hepatocellular lipid accumulation and ballooning, which is also accompanied by capillarization and dysfunction of liver sinusoidal endothelial cells. Both of these impaired mechanical and molecular components can cause an increase in intrahepatic vascular resistance which lead to the increase of portal pressure in the absence of significant liver fibrosis. Extrahepatic factors such as insulin resistance and gut dysbiosis may also contribute to liver sinusoidal endothelial dysfunction and early portal hypertension in NAFLD. The clinical impact of early portal hypertension in NAFLD is still unclear. However, clinical tools for diagnosis and monitoring of portal hypertension in NAFLD are being investigated to predict high-risk patients and to guide therapy.

SGLT2 Inhibitors in Chronic Kidney Disease: From Mechanisms to Clinical Practice

In recent years, sodium-glucose co-transporter 2 inhibitors (SGLT2i) have demonstrated beneficial renoprotective effects, which culminated in the recent approval of their use for patients with chronic kidney disease (CKD), following a similar path to one they had already crossed due to their cardioprotective effects, meaning that SGLT2i represent a cornerstone of heart failure therapy. In the present review, we aimed to discuss the pathophysiological mechanisms operating in CKD that are targeted with SGLT2i, either directly or indirectly. Furthermore, we presented clinical evidence of SGLT2i in CKD with respect to the presence of diabetes mellitus. Despite initial safety concerns with regard to euglycemic diabetic ketoacidosis and transient decline in glomerular filtration rate, the accumulating clinical data are reassuring. In summary, although SGLT2i provide clinicians with an exciting new treatment option for patients with CKD, further research is needed to determine which subgroups of patients with CKD will benefit the most, and which the least, from this therapeutical option.

In-hospital arrhythmic burden reduction in diabetic patients with acute myocardial infarction treated with SGLT2-inhibitors: Insights from the SGLT2-I AMI PROTECT study

Background

Sodium-glucose co-transporter 2 inhibitors (SGLT2-i) have shown significant cardiovascular benefits in patients with and without type 2 diabetes mellitus (T2DM). They have also gained interest for their potential anti-arrhythmic role and their ability to reduce the occurrence of atrial fibrillation (AF) and ventricular arrhythmias (VAs) in T2DM and heart failure patients.

Objectives

To investigate in-hospital new-onset cardiac arrhythmias in a cohort of T2DM patients presenting with acute myocardial infarction (AMI) treated with SGLT2-i vs. other oral anti-diabetic agents (non-SGLT2-i users).

Methods

Patients from the SGLT2-I AMI PROTECT registry (NCT05261867) were stratified according to the use of SGLT2-i before admission for AMI, divided into SGLT2-i users vs. non-SGLT2-i users. In-hospital outcomes included the occurrence of in-hospital new-onset cardiac arrhythmias (NOCAs), defined as a composite of new-onset AF and sustained new-onset ventricular tachycardia (VT) and/or ventricular fibrillation (VF) during hospitalization.

Results

The study population comprised 646 AMI patients categorized into SGLT2-i users (111 patients) and non-SGLT2-i users (535 patients). SGLT2-i users had a lower rate of NOCAs compared with non-SGLT2-i users (6.3 vs. 15.7%, p = 0.010). Moreover, SGLT2-i was associated with a lower rate of AF and VT/VF considered individually (p = 0.032). In the multivariate logistic regression model, after adjusting for all confounding factors, the use of SGLT2-i was identified as an independent predictor of the lower occurrence of NOCAs (OR = 0.35; 95%CI 0.14-0.86; p = 0.022). At multinomial logistic regression, after adjusting for potential confounders, SGLT2-i therapy remained an independent predictor of VT/VF occurrence (OR = 0.20; 95%CI 0.04-0.97; p = 0.046) but not of AF occurrence.

Conclusions

In T2DM patients, the use of SGLT2-i was associated with a lower risk of new-onset arrhythmic events during hospitalization for AMI. In particular, the primary effect was expressed in the reduction of VAs. These findings emphasize the cardioprotective effects of SGLT2-i in the setting of AMI beyond glycemic control.

Trial registration

Data are part of the observational international registry: SGLT2-I AMI PROTECT. ClinicalTrials.gov, identifier: NCT05261867.

A review of cardiovascular benefits of SGLT2 inhibitors

Sodium-glucose cotransporter 2 inhibitor (SGLT2I) is a new type of hypoglycemic drug that targets the kidney. As research continues to advance on this topic, it has been found that SGLT2I has multiple protective effects, such as hypoglycemic, cardio-renal protective, antihypertensive, and lipid-lowering effects. This review discusses the current concepts and possible mechanisms of SGLT2I in the treatment of heart failure, myocardial infarction, hypertension, cardiomyopathy and arrhythmia to provide a reference for clinicians to use drugs more reasonably and scientifically.

SGLT2 Inhibitor Empagliflozin Modulates Ion Channels in Adult Zebrafish Heart

Empagliflozin, an inhibitor of sodium-glucose co-transporter 2 (iSGLT2), improves cardiovascular outcomes in patients with and without diabetes and possesses an antiarrhythmic activity. However, the mechanisms of these protective effects have not been fully elucidated. This study aimed to explore the impact of empagliflozin on ion channel activity and electrophysiological characteristics in the ventricular myocardium. The main cardiac ionic currents (I_Na, I_CaL, I_CaT, I_Kr, I_Ks) and action potentials (APs) were studied in zebrafish. Whole-cell currents were measured using the patch clamp method in the isolated ventricular cardiomyocytes. The conventional sharp glass microelectrode technique was applied for the recording of APs from the ventricular myocardium of the excised heart. Empagliflozin pretreatment compared to the control group enhanced potassium I_Kr step current density in the range of testing potentials from 0 to +30 mV, I_Kr tail current density in the range of testing potentials from +10 to +70 mV, and I_Ks current density in the range of testing potentials from −10 to +20 mV. Moreover, in the ventricular myocardium, empagliflozin pretreatment shortened AP duration APD as shown by reduced APD50 and APD90. Empagliflozin had no influence on sodium (I_Na) and L- and T-type calcium currents (I_CaL and I_CaT) in zebrafish ventricular cardiomyocytes. Thus, we conclude that empagliflozin increases the rapid and slow components of delayed rectifier K⁺ current (I_Kr and I_Ks). This mechanism could be favorable for cardiac protection.

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.

Impact of sodium-glucose co-transporter inhibitors on cardiac autonomic function and mortality: no time to die

Sodium-glucose co-transporter 2 (SGLT2) inhibitors have been shown to improve cardiovascular outcomes not only in patients with diabetes but also in those with heart failure, irrespective of diabetic status. However, the mechanisms underlying the cardioprotective effects of these newer anti-diabetic drugs remain to be fully elucidated. One exciting avenue that has been recently explored in both preclinical and clinical studies is the modulation of the cardiovascular autonomic nervous system. A reduction in sympathetic nervous system activity by SGLT2 inhibitors may potentially translate into a reduction in arrhythmic risk and sudden arrhythmic death, which may explain, at least partly, the cardioprotection shown in the cardiovascular outcome trials with different SGLT2 inhibitors. Although some of the data from the preclinical and clinical studies are promising, overall the findings can be contradictory. This highlights the need for more studies to address gaps in our knowledge of these novel drugs. The present review offers an in depth overview of the existing literature regarding the role of SGLT2 inhibitors in modulating cardiovascular autonomic function as one of the possible pathways of their cardioprotective effects.

Sodium-Glucose Cotransporter-2 Inhibitors-from the Treatment of Diabetes to Therapy of Chronic Heart Failure

Sodium-glucose cotransporter-2 (SGLT2) inhibitors are currently the second-line pharmacotherapy in type 2 diabetes, particularly through their effectiveness in reducing glycemia, but also due to their cardioprotective and nephroprotective effects. In light of surprisingly satisfactory results from large, randomized trials on gliflozins, SGLT2 received the highest recommendation (Class IA) with the highest level of evidence (A) in the treatment algorithm for HF with reduced LVEF in recent ESC HF guidelines. This great breakthrough in the treatment of HF is due to different mechanisms of action of gliflozins that are reported to be able to change the natural course of HF by reducing the risk of both hospitalization and death. They are recommended regardless of the patient’s diabetes status. This review summarizes the up-to-date literature on their beneficial and pleiotropic impact on the cardiovascular system.

Sodium-glucose cotransporter 2 inhibitors as the first universal treatment of chronic kidney disease

In the last five years, the medical community was astonishingly surprised by the sequential large outcome trials that displayed the renal effects of sodium glucose co-transporter inhibitors (SGLT2Is) in type 2 diabetes mellitus (T2DM) patients with or without chronic kidney disease (CKD). This favorable effect was later disclosed in non-diabetic CKD patients. The EMPA-REG OUTCOME trial was the first trial that showed a reduction for the need for dialysis in patients suffering diabetic kidney disease (DKD) by 55%. This figure is double the score achieved by the angiotensin receptor blocker, Losartan, in RENAAL trial. The need for dialysis in DAPA-CKD trial was reduced in diabetic and non-diabetic CKD patients by 33%. The renal-specific composite outcome was reduced by 39% in EMPA-REG trial, 40% in CANVAS study, 47% in DECLARE-TIMI 58 study, 34% in CREDENCE trial, and 44% in DAPA-CKD trial. The greater surprise is the significant favorable effect of SGLT2Is on overall mortality in CKD patients with or without T2DM. Similar survival benefit was not previously encountered with any of the medications used in CKD patients with or without diabetes. In this review, we disclose the results of the DAPA-CKD trial, the CREDENCE trial and those of several cardiovascular outcome trials (CVOT) that used different SGLT2Is and showed that patients with lower eGFR levels may have greater benefit with respect to cardiovascular morbidity than patients with normal kidney function. In addition, we discuss the different mechanisms of action that explain the renal beneficial effects of SGLT2Is.

Kidney Angiotensin in Cardiovascular Disease: Formation and Drug Targeting

The concept of local formation of angiotensin II in the kidney has changed over the last 10-15 years. Local synthesis of angiotensinogen in the proximal tubule has been proposed, combined with prorenin synthesis in the collecting duct. Binding of prorenin via the so-called (pro)renin receptor has been introduced, as well as megalin-mediated uptake of filtered plasma-derived renin-angiotensin system (RAS) components. Moreover, angiotensin metabolites other than angiotensin II [notably angiotensin-(1-7)] exist, and angiotensins exert their effects via three different receptors, of which angiotensin II type 2 and Mas receptors are considered renoprotective, possibly in a sex-specific manner, whereas angiotensin II type 1 (AT1) receptors are believed to be deleterious. Additionally, internalized angiotensin II may stimulate intracellular receptors. Angiotensin-converting enzyme 2 (ACE2) not only generates angiotensin-(1-7) but also acts as coronavirus receptor. Multiple, if not all, cardiovascular diseases involve the kidney RAS, with renal AT1 receptors often being claimed to exert a crucial role. Urinary RAS component levels, depending on filtration, reabsorption, and local release, are believed to reflect renal RAS activity. Finally, both existing drugs (RAS inhibitors, cyclooxygenase inhibitors) and novel drugs (angiotensin receptor/neprilysin inhibitors, sodium-glucose cotransporter-2 inhibitors, soluble ACE2) affect renal angiotensin formation, thereby displaying cardiovascular efficacy. Particular in the case of the latter three, an important question is to what degree they induce renoprotection (e.g., in a renal RAS-dependent manner). This review provides a unifying view, explaining not only how kidney angiotensin formation occurs and how it is affected by drugs but also why drugs are renoprotective when altering the renal RAS. SIGNIFICANCE STATEMENT: Angiotensin formation in the kidney is widely accepted but little understood, and multiple, often contrasting concepts have been put forward over the last two decades. This paper offers a unifying view, simultaneously explaining how existing and novel drugs exert renoprotection by interfering with kidney angiotensin formation.

Dapagliflozin for the treatment of chronic kidney disease

INTRODUCTION

Sodium-dependent glucose cotransporter 2 (SGLT2) is a glucose transporter expressed on the proximal tubular cells, where it reabsorbs glucose from the glomerular filtrate. SGLT2 inhibitors (SGLT2is), initially developed as an antidiabetic drug, have recently attracted considerable attention because they have cardiorenal protective effects. Among SGLT2is, dapagliflozin was the first to demonstrate the renoprotective effect in patients with and without diabetes and has been approved for chronic kidney disease (CKD) treatment.

AREAS COVERED

This review covers the pharmacological characteristics and the clinical efficacy and safety profiles of dapagliflozin, including comparison with other SGLT2is and risk modification strategies.

EXPERT OPINION

In DAPA-CKD, dapagliflozin reduced the primary outcome (≥50% estimated glomerular filtration rate [eGFR] decline, end-stage kidney disease [ESKD], or renal or cardiovascular [CV] death) by 39% in CKD patients. This beneficial effect was consistent across prespecified subgroups, including those based on the presence of diabetes. Dapagliflozin also decreased the CV composite outcome and all-cause death by 29% and 31%, respectively. Although an increased risk of adverse events such as ketoacidosis and volume depletion has been reported, the robust renal and CV benefits of dapagliflozin are expected to outweigh potential risks. SGLT2is, including dapagliflozin, will constitute the mainstay of CKD treatment.

Mechanisms underlying the blood pressure lowering effects of dapagliflozin, exenatide, and their combination in people with type 2 diabetes: a secondary analysis of a randomized trial

BACKGROUND

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP-1RA) lower blood pressure (BP). When SGLT2i and GLP-1RA are combined, synergistic effects on BP have been observed. The mechanisms underlying these BP reductions are incompletely understood. The aim of this study was to assess the mechanisms underlying the BP reduction with the SGLT2i dapagliflozin, GLP-1RA exenatide, and dapagliflozin-exenatide compared with placebo in people with obesity and type 2 diabetes.

METHODS

Sixty-six people with type 2 diabetes were randomized to 16 weeks of dapagliflozin 10 mg/day, exenatide 10 µg twice daily, dapagliflozin-exenatide, or placebo treatment. The effect of treatments on estimates of: (1) plasma volume (calculated by Strauss formula, bioimpedance spectroscopy, hematocrit, (2) autonomic nervous system activity (heart rate variability), (3) arterial stiffness (pulse wave applanometry), (4) systemic hemodynamic parameters including peripheral vascular resistance, cardiac output and stroke volume (all derived from non-invasively systemic hemodynamic monitoring), and (5) natriuresis (24-hour urine collection) were assessed after 10 days and 16 weeks of treatment.

RESULTS

After 10 days, dapagliflozin reduced systolic BP (SBP) by - 4.7 mmHg, and reduced plasma volume. After 16 weeks, dapagliflozin reduced SBP by - 4.4 mmHg, and reduced sympathetic nervous system (SNS) activity. Exenatide had no effect on SBP, but reduced parasympathetic nervous system activity after 10 days and 16 weeks. After 10 days, dapagliflozin-exenatide reduced SBP by - 4.2 mmHg, and reduced plasma volume. After 16 weeks, dapagliflozin-exenatide reduced SBP by - 6.8 mmHg, and the reduction in plasma volume was still observed, but SNS activity was unaffected.

CONCLUSIONS

The dapagliflozin-induced plasma volume contraction may contribute to the initial SBP reduction, while a reduction in SNS activity may contribute to the persistent SBP reduction. Dapagliflozin-exenatide resulted in the largest decrease in SBP. The effect on plasma volume was comparable to dapagliflozin monotherapy, and SNS activity was not reduced, therefore other mechanisms are likely to contribute to the blood pressure lowering effect of this combination, which need further investigation. Trial registration Clinicaltrials.gov, NCT03361098.

Empagliflozin Ameliorates Preeclampsia and Reduces Postpartum Susceptibility to Adriamycin in a Mouse Model Induced by Angiotensin Receptor Agonistic Autoantibodies

Preeclampsia (PE) is the leading cause of maternal and perinatal morbidity and mortality and also is a risk factor for cardiovascular and kidney disease later in life. PE is associated with oversecretion of autoantibodies against angiotensin II type 1 receptor (AT1-AA) by the placenta into the maternal circulation. Here, we sought to determine the therapeutic value of the sodium-glucose co-transporter 2 (SGLT2) inhibitor empagliflozin (EMPA) in mice with AT1-AA-induced preeclampsia. Pregnant mice were injected with AT1-AA at gestation day (GD) 13 and treated daily with EMPA until GD 19, at which point some of the maternal mice were sacrificed and assessed. The other maternal mice were labored on time and challenged with adriamycin (ADR) at 12 weeks postpartum; their offspring were assessed for fetal outcomes. We showed that EMPA treatment significantly relieved high systolic blood pressure and proteinuria and ameliorated kidney injury in PE mice without affecting fetal outcomes. EMPA also ameliorated podocyte injury and oxidative stress, reduced the expression of SGLT2 and activated the AMPK/SIRT1 signaling pathway in vivo and in vitro. Remarkably, EMPA treatment during pregnancy reduced ADR-induced kidney and podocyte injury postpartum. These findings suggest that EMPA could be a potential pharmacological agent for PE.

Cellular interplay between cardiomyocytes and non-myocytes in diabetic cardiomyopathy

Patients with Type 2 diabetes mellitus (T2DM) frequently exhibit a distinctive cardiac phenotype known as diabetic cardiomyopathy. Cardiac complications associated with T2DM include cardiac inflammation, hypertrophy, fibrosis and diastolic dysfunction in the early stages of the disease, which can progress to systolic dysfunction and heart failure. Effective therapeutic options for diabetic cardiomyopathy are limited and often have conflicting results. The lack of effective treatments for diabetic cardiomyopathy is due in part, to our poor understanding of the disease development and progression, as well as a lack of robust and valid preclinical human models that can accurately recapitulate the pathophysiology of the human heart. In addition to cardiomyocytes, the heart contains a heterogeneous population of non-myocytes including fibroblasts, vascular cells, autonomic neurons and immune cells. These cardiac non-myocytes play important roles in cardiac homeostasis and disease, yet the effect of hyperglycaemia and hyperlipidaemia on these cell types are often overlooked in preclinical models of diabetic cardiomyopathy. The advent of human induced pluripotent stem cells provides a new paradigm in which to model diabetic cardiomyopathy as they can be differentiated into all cell types in the human heart. This review will discuss the roles of cardiac non-myocytes and their dynamic intercellular interactions in the pathogenesis of diabetic cardiomyopathy. We will also discuss the use of sodium-glucose cotransporter 2 inhibitors as a therapy for diabetic cardiomyopathy and their known impacts on non-myocytes. These developments will no doubt facilitate the discovery of novel treatment targets for preventing the onset and progression of diabetic cardiomyopathy.

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.

Interaction between sodium-glucose co-transporter 2 and the sympathetic nervous system

PURPOSE OF REVIEW

Sodium-glucose co-transporter 2 (SGLT2) inhibitors have taken centre stage in research and therapeutic efforts to modulate hard clinical outcomes in patients with heightened cardiovascular and renal risk profiles. Sympathetic nervous system (SNS) activation is a prominent feature across several cardiovascular and renal disease states. This review reflects on the remarkable clinical impact of SGLT2 inhibitors on cardiorenal outcomes, and navigates the evidence for a proposed clinically relevant interaction between SGLT2 and the SNS.

RECENT FINDINGS

SGLT2 inhibitors exert several pleiotropic effects beyond glucose-lowering. These include, but are not limited to, diuresis and natriuresis, blood pressure lowering, reduction in inflammation and oxidative stress, stimulation of erythropoiesis, and improvement in cardiac energetics. Treatment with SGLT2 inhibitors is associated with significant improvement in cardiorenal outcomes irrespective of diabetes status. In addition, evidence from preclinical studies points to a strong signal of a bidirectional temporal association between SGLT2 inhibition and reduction in SNS activation.

SUMMARY

Ongoing preclinical and clinical trials aimed at unravelling the proposed interaction between SGLT and SNS will enhance our understanding of their individual and/or collective contributions to cardiovascular disease progression and guide future targeted therapeutic interventions.

Newer Drugs to Reduce High Blood Pressure and Mitigate Hypertensive Target Organ Damage

PURPOSE OF REVIEW

This review aims to investigate the blood pressure (BP)-lowering effects of emerging drugs developed to treat diabetic kidney disease and heart failure (HF). We summarize the potential pathophysiological mechanisms responsible for mitigating hypertensive target organ damage and evaluating the available clinical data on these newer drugs.

RECENT FINDINGS

Nonsteroidal dihydropyridine-based mineralocorticoid receptor antagonists (MRAs), dual angiotensin II receptor-neprilysin inhibitors (valsartan with sacubitril), sodium-glucose cotransporter 2 inhibitors (SGLT2i), and soluble guanylate cyclase stimulators are new classes of chemical agents that have distinct mechanisms of action and have been shown to be effective for the treatment of cardiovascular (CV) disease (CVD), HF, and type 2 diabetes mellitus (T2D). These drugs can be used either alone or in combination with other antihypertensive and CV drugs. Among these, SGLT2i and valsartan with sacubitril offer new avenues to reduce CVD mortality. SGLT2i have a mild-to-moderate effect on BP lowering with a favorable effect on CV and renal hemodynamics and have been shown to produce a significant reduction in the incidence of major adverse CVD events (as monotherapy or add-on therapy) compared with controls (placebo or non-SGLT2i treatment). Most of the participants in these studies had hypertension (HTN) at baseline and were receiving antihypertensive therapy, including renin-angiotensin system blockers. The combination of valsartan with sacubitril also lowers BP in the short term and has demonstrated a striking reduction in CVD mortality and morbidity in HF patients with a reduced left ventricular ejection fraction. If widely adopted, these novel therapeutic agents hold significant promise for reducing the public health burden posed by HTN and CVD. Based on the results of several clinical trials and considering the high prevalence of HTN and T2D, these new classes of agents have emerged as powerful therapeutic tools in managing and lowering the BP of patients with diabetic kidney disease and HF.

Growing role of SGLT2i in heart failure: evidence from clinical trials

INTRODUCTION

: There is an unmet need for therapies that improve overall mortality and morbidity for patients with preserved ejection fraction, who comprise roughly half of all heart failure (HF) cases. The growing role of sodium-glucose cotransporter-2 inhibitors (SGLT2is) in cardiovascular outcomes provides a paradigm shift in the treatment of HF.

AREAS COVERED

: This review article provides a general overview of the growing role of SGLT2is and summarizes the mechanism of action, side effects, and contraindications for the treatment of HF. We also discuss recent clinical trials measuring the effects of different SGLT2is as possible treatment options for HF with reduced ejection fraction and HF with mid-range and preserved EF. We conducted a review of all the randomized, controlled studies with SGLT2is in patients with known heart failure with and without type-2 diabetes (T2DM). We performed a literature search in PubMed, Google Scholar, the Web of Science, and the Cochrane Library while screening results by the use of titles and abstracts.

EXPERT OPINION

: The promising pathophysiological profile of SGLT2i and their role in cardioprotective effects demonstrate an invaluable discovery in the management of patients with HF irrespective of their diabetes status.

Effects and mechanisms of SGLT2 inhibitors on the NLRP3 inflammasome, with a focus on atherosclerosis

Atherosclerosis is a lipid-driven chronic inflammatory disease that is widespread in the walls of large and medium-sized arteries. Its pathogenesis is not fully understood. The currently known pathogenesis includes activation of pro-inflammatory signaling pathways in the body, increased oxidative stress, and increased expression of cytokines/chemokines. In the innate immune response, inflammatory vesicles are an important component with the ability to promote the expression and maturation of inflammatory factors, release large amounts of inflammatory cytokines, trigger a cascade of inflammatory responses, and clear pathogens and damaged cells. Studies in the last few years have demonstrated that NLRP3 inflammatory vesicles play a crucial role in the development of atherosclerosis as well as its complications. Several studies have shown that NLRP3 binding to ligands promotes inflammasome formation, activates caspase-1, and ultimately promotes its maturation and the maturation and production of IL-1β and IL-18. IL-1β and IL-18 are considered to be the two most prominent inflammatory cytokines in the inflammasome that promote the development of atherosclerosis. SGLT2 inhibitors are novel hypoglycemic agents that also have significant antiatherosclerotic effects. However, their exact mechanism is not yet clear. This article is a review of the literature on the effects and mechanisms of SGLT2 inhibitors on the NLRP3 inflammasome, focusing on their role in antiatherosclerosis.

Cardiorenal protection with SGLT2 inhibitors in patients with diabetes mellitus: from biomarkers to clinical outcomes in heart failure and diabetic kidney disease

Type 2 diabetes (T2D) is one of the most common causes of chronic kidney disease (CKD) and cardiovascular (CV) disease. Until recently, glycemic and BP control were the cornerstones for preventing progression of CKD and CV disease associated with T2D. However, there has been a paradigm shift in treatment since the publication of the first clinical trial demonstrating benefits of sodium glucose cotransporter 2 (SGLT2) inhibitors in 2015. SGLT2 inhibitors have been shown to reduce the risk of major adverse CV events and progression of kidney disease in the setting of T2D. However, the elucidation of mechanisms of underlying these clinical benefits is the subject of ongoing investigation. Experimental studies have shown that SGLT2 inhibitors have diverse pleiotropic effects such as modulation of neurohormones such as the renin-angiotensin-aldosterone system, increasing hematocrit, altering energy substrate use, and attenuating systemic inflammation and oxidative stress, all of which have been implicated in the CV and kidney protective effects of SGLT2 inhibitors. In this review, we highlight biomarkers linked with diabetic kidney disease and heart failure and discuss how SGLT2 inhibitor-associated changes potentially mediate the cardiorenal protection observed with these therapies.

Effects of the sodium-glucose cotransporter 2 inhibitor empagliflozin on vascular function in patients with chronic heart failure

AIMS

Impairment of vascular function contributes to the progression of chronic heart failure (HF) by increasing the afterload. Treatment with selective sodium-glucose cotransporter 2 (SGLT2) inhibitors improves the prognosis of HF, but the precise mechanisms remain unclear. The aim of this study was to analyse the effect of empagliflozin on vascular function in patients with HF.

METHODS AND RESULTS

In an investigator initiated, double-blind, randomized, placebo-controlled, parallel-group, clinical study, patients with HF NYHA II-III and an ejection fraction of 49% or less were randomized 2:1 to receive empagliflozin 10 mg once daily or placebo for 3 months. A total of 74 patients (15% female), aged 66 ± 9 years, with a mean ejection fraction of 39 ± 8% and a median NTproBNP of 558 pg/mL (IQR 219-1051 pg/mL), were included. Vascular parameters such as central systolic blood pressure (cSBP), central pulse pressure (cPP), forward (FPH), and reflected pressure pulse height (RPH) decreased under resting conditions after 1 and 3 months (1 month: cSBP -6.4 ± 8.3 mmHg, P < 0.001, cPP -3.0 ± 6.6 mmHg, P = 0.004, FPH -2.5 ± 4.5 mmHg, P = 0.001, RPH -1.6 ± 3.0 mmHg, P = 0.001; 3 months: cSBP -4.6 ± 8.4 mmHg, P = 0.001, cPP -3.1 ± 4.8 mmHg, P < 0.001, FPH -1.7 ± 3.7 mmHg, P = 0.004, RPH -1.4 ± 2.5 mmHg, P = 0.001) in patients treated with empagliflozin (n = 45). In accordance, cSBP and cPP decreased in patients with empagliflozin treatment under 24 h ambulatory conditions after 1 and 3 months (1 month: cSBP -4.8 ± 10.1 mmHg, P = 0.003, cPP -2.0 ± 5.7 mmHg, P = 0.026; 3 months: cSBP -4.7 ± 9.0 mmHg, P = 0.002, cPP -2.1 ± 6.4 mmHg, P = 0.044). In the placebo group, there was no significant change after 1 and 3 months. The decrease in cSBP under resting conditions (-5.7 ± 2.4 mmHg, P = 0.019) after 1 month and in cSBP (-6.0 ± 2.6, P = 0.027) as well as in pulse wave velocity (-0.5 ± 0.2 m/s, P = 0.021) under 24 h ambulatory conditions after 3 months was greater in the empagliflozin group than in the placebo group.

CONCLUSIONS

We found an improvement of vascular function after treatment with empagliflozin that indicates decreased afterload of the left ventricle and may contribute to the beneficial effects of SGLT2 inhibition in HF.

Different Responses of Muscle Sympathetic Nerve Activity to Dapagliflozin Between Patients With Type 2 Diabetes With and Without Heart Failure

Background Sodium-glucose cotransporter 2 inhibitors improve cardiovascular outcomes in patients with diabetes with and without heart failure (HF). However, their influence on sympathetic nerve activity (SNA) remains unclear. The purpose of this study was to evaluate the effect of sodium-glucose cotransporter 2 inhibitors on SNA and compare the responses of SNA to sodium-glucose cotransporter 2 inhibitors in patients with type 2 diabetes with and without HF. Methods and Results Eighteen patients with type 2 diabetes, 10 with HF (65.4±3.68 years) and 8 without HF (63.3±3.62 years), were included. Muscle SNA (MSNA), heart rate, and blood pressure were recorded before and 12 weeks after administration of dapagliflozin (5 mg/day). Sympathetic and cardiovagal baroreflex sensitivity were simultaneously calculated. Brain natriuretic peptide level increased significantly at baseline in patients with HF than those without HF, while MSNA, blood pressure, and hemoglobin A1c did not differ between the 2 groups. Fasting blood glucose and homeostatic model assessment of insulin resistance did not change in either group after administering dapagliflozin. MSNA decreased significantly in both groups. However, the reduction in MSNA was significantly higher in patients with HF than patients with non-HF (-20.2±3.46 versus -9.38±3.65 bursts/100 heartbeats; P=0.049), which was concordant with the decrease in brain natriuretic peptide. Conclusions Dapagliflozin significantly decreased MSNA in patients with type 2 diabetes regardless of its blood glucose-lowering effect. Moreover, the reduction in MSNA was more prominent in patients with HF than in patients with non-HF. These results indicate that the cardioprotective effects of sodium-glucose cotransporter 2 inhibitors may, in part, be attributed to improved SNA.

Impact of SGLT2 inhibitors in comparison with DPP4 inhibitors on ascites and death in veterans with cirrhosis on metformin

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) may have favourable neurohumoral and metabolic effects in patients with chronic liver disease. However, studies examining SGLT2i in this population have been limited to patients with non-alcoholic fatty liver disease and have focused on surrogate biomarkers. Our aim was to evaluate whether SGLT2i can reduce the incidence of ascites and death over a period of 36 months in patients with cirrhosis and diabetes mellitus. Using electronic health data from Veterans Affairs hospitals in the United States, we conducted a propensity score matched intention-to-treat analysis among veterans on metformin who subsequently received either SGLT2i or dipeptidyl peptidase-4 inhibitors. Among 423 matched pairs (in total, 846 patients), we found no significant difference in the risk for ascites (hazard ratio 0.68 for SGLT2i, 95% confidence interval 0.37-1.25; p = .22) but did find that SGLT2i users had a reduced risk for death (adjusted hazard ratio 0.33, 95% confidence interval 0.11-0.99; p < .05). In comparison with dipeptidyl peptidase-4 inhibitors, SGLT2i may improve survival for patients with cirrhosis who require additional pharmacotherapy for diabetes mellitus beyond metformin, but confirmatory studies are necessary.

Sodium-glucose cotransporter 2 inhibitors as the first universal treatment of chronic kidney disease

In the last five years, the medical community was astonishingly surprised by the sequential large outcome trials that displayed the renal effects of sodium glucose co-transporter inhibitors (SGLT2Is) in type 2 diabetes mellitus (T2DM) patients with or without chronic kidney disease (CKD). This favorable effect was later disclosed in non-diabetic CKD patients. The EMPA-REG OUTCOME trial was the first trial that showed a reduction for the need for dialysis in patients suffering diabetic kidney disease (DKD) by 55%. This figure is double the score achieved by the angiotensin receptor blocker, Losartan, in RENAAL trial. The need for dialysis in DAPA-CKD trial was reduced in diabetic and non-diabetic CKD patients by 33%. The renal-specific composite outcome was reduced by 39% in EMPA-REG trial, 40% in CANVAS study, 47% in DECLARE-TIMI 58 study, 34% in CREDENCE trial, and 44% in DAPA-CKD trial. The greater surprise is the significant favorable effect of SGLT2Is on overall mortality in CKD patients with or without T2DM. Similar survival benefit was not previously encountered with any of the medications used in CKD patients with or without diabetes. In this review, we disclose the results of the DAPA-CKD trial, the CREDENCE trial and those of several cardiovascular outcome trials (CVOT) that used different SGLT2Is and showed that patients with lower eGFR levels may have greater benefit with respect to cardiovascular morbidity than patients with normal kidney function. In addition, we discuss the different mechanisms of action that explain the renal beneficial effects of SGLT2Is.

Inhibition of sodium-glucose cotransporter 2 to slow the progression of chronic kidney disease

Chronic kidney disease (CKD) is a major public health problem, increasing the risk of cardiovascular events and death and potentially leading to kidney failure. Novel drugs that slow the progression of this non-communicable disease are therefore urgently needed. Initially developed as glucose-lowering drugs, inhibitors of the sodium-glucose cotransporter 2 (SGLT2) drastically reduce the overall mortality and cardiovascular events and slow the progression of CKD. Kidney protection conferred by SGLT2 inhibitors is independent from the presence of diabetes, observed on top of renin-angiotensin system inhibition and consistent across a wide range of categories of glomerular filtration rate and albuminuria. The mechanisms through which SGLT2 inhibitors improve kidney outcomes are likely multifactorial. Inhibition of SGLT2 in the kidney proximal tubule results in natriuresis and glucosuria, with beneficial effects on metabolic control, blood pressure and body weight. In addition, SGLT2 inhibitors also improve intraglomerular hemodynamics, podocyte integrity, cell metabolism, and erythropoiesis and reduce hypoxia, oxidative stress, sympathetic nervous activity, inflammation and fibrosis. The major impact of SGLT2 inhibitors on kidney outcomes, along with the excellent safety profile of this new class of drugs, open novel avenues for the treatment of CKD in patients with and without diabetes.

Impact of Sodium-Glucose Co-Transporter 2 Inhibitors on Cardiac Protection

Sodium–glucose co-transporter 2 (SGLT2) inhibitors have been approved as a new class of anti-diabetic drugs for type 2 diabetes mellitus (T2DM). The SGLT2 inhibitors reduce glucose reabsorption through renal systems, thus improving glycemic control in all stages of diabetes mellitus, independent of insulin. This class of drugs has the advantages of no clinically relevant hypoglycemia and working in synergy when combined with currently available anti-diabetic drugs. While improving sugar level control in these patients, SGLT2 inhibitors also have the advantages of blood-pressure improvement and bodyweight reduction, with potential cardiac and renal protection. In randomized control trials for patients with diabetes, SGLT2 inhibitors not only improved cardiovascular and renal outcomes, but also hospitalization for heart failure, with this effect extending to those without diabetes mellitus. Recently, dynamic communication between autophagy and the innate immune system with Beclin 1-TLR9-SIRT3 complexes in response to SGLT2 inhibitors that may serve as a potential treatment strategy for heart failure was discovered. In this review, the background molecular pathways leading to the clinical benefits are examined in this new class of anti-diabetic drugs, the SGLT2 inhibitors.

Could Dapagliflozin Attenuate COVID-19 Progression in High-Risk Patients With or Without Diabetes? Behind DARE-19 Concept

ABSTRACT

Epidemiological studies indicate that diabetes is the second most common comorbidity in COVID-19 (coronavirus disease 2019). Dapagliflozin, a sodium-glucose co-transporter 2 inhibitor, exerts direct cardioprotective and nephroprotective effects. DARE-19 (Dapagliflozin in Respiratory Failure in Patients With COVID-19), an ongoing clinical trial, is designed to investigate the impact of dapagliflozin on COVID-19 progression. This article discusses the potential favorable impact of dapagliflozin on COVID-19 and its complications.

Effects of 6 weeks of treatment with dapagliflozin, a sodium-glucose co-transporter-2 inhibitor, on myocardial function and metabolism in patients with type 2 diabetes: A randomized, placebo-controlled, exploratory study

AIM

To explore the early effects of dapagliflozin on myocardial function and metabolism in patients with type 2 diabetes without heart failure.

MATERIALS AND METHODS

Patients with type 2 diabetes on metformin treatment were randomized to double-blind, 6-week placebo or dapagliflozin 10 mg daily treatment. Investigations included cardiac function and structure with myocardial resonance imaging; cardiac oxygen consumption, perfusion and efficiency with [¹¹ C]-acetate positron emission tomography (PET); and cardiac and hepatic fatty acid uptake with [¹⁸ F]-6-thia-heptadecanoic acid PET, analysed by ANCOVA as least square means with 95% confidence intervals.

RESULTS

Evaluable patients (placebo: n = 24, dapagliflozin: n = 25; 53% males) had a mean age of 64.4 years, a body mass index of 30.2 kg/m² and an HbA1c of 6.7%. Body weight and HbA1c were significantly decreased by dapagliflozin versus placebo. Dapagliflozin had no effect on myocardial efficiency, but external left ventricular (LV) work (-0.095 [-0.145, -0.043] J/g/min) and LV oxygen consumption were significantly reduced (-0.30 [-0.49, -0.12] J/g/min) by dapagliflozin, although the changes were not statistically significant versus changes in the placebo group. Change in left atrial maximal volume with dapagliflozin versus placebo was -3.19 (-6.32, -0.07) mL/m² (p = .056). Peak global radial strain decreased with dapagliflozin versus placebo (-3.92% [-7.57%, -0.28%]; p = .035), while peak global longitudinal and circumferential strains were unchanged. Hepatic fatty acid uptake was increased by dapagliflozin versus placebo (0.024 [0.004, 0.044] μmol/g/min; p = .018), while cardiac uptake was unchanged.

CONCLUSIONS

This exploratory study indicates reduced heart work but limited effects on myocardial function, efficiency and cardiac fatty acid uptake, while hepatic fatty acid uptake increased, after 6 weeks of treatment with dapagliflozin.