Glycemic control by the SGLT2 inhibitor empagliflozin decreases aortic stiffness, renal resistivity index and kidney injury

The current landscape for diabetes treatment: Preventing diabetes-associated CV risk

Despite the risk of atherosclerosis has progressively declined over the past few decades, subjects with type 2 diabetes mellitus (T2DM) continue to experience substantial excess of atherosclerotic cardiovascular disease (ASCVD)-related events. Therefore, there is urgent need to treat ASCVD disease in T2DM earlier, more intensively, and with greater precision. Many factors concur to increase the risk of atherosclerosis, and multifactorial intervention remains the basis for effective prevention or reduction of atherosclerotic events. The role of anti-hyperglycemic medications in reducing the risk of ASCVD in subjects with T2DM has evolved over the past few years. Multiple cardiovascular outcome trials (CVOTs) with new and emerging glucose-lowering agents, namely SGLT2 inhibitors (SGLT2i) and GLP-1 receptor agonists (GLP1-RA), have demonstrated significant reductions of major cardiovascular events and additional benefits. This robust evidence has changed the landscape for managing people with T2DM. In addition to glycemic and ancillary extra-glycemic properties, SGLT2i and GLP1-RA might exert favorable effects on subclinical and clinical atherosclerosis. Therefore, the objective of this review is to discuss the available evidence supporting anti-atherosclerotic properties of SGLT2i and GLP1-RA, with a quick nod to sotagliflozin and tirzepatide.

Innovative Treatments to Counteract Endothelial Dysfunction in Chronic Kidney Disease Patients

In chronic kidney disease (CKD) patients, several risk factors contribute to the development of endothelial dysfunction (ED), which can be described as an alteration in the cell structure or in the function of the endothelium. Among the well-known CKD-related risk factors capable of altering the production of endothelium-derived relaxing factors, we include asymmetric dimethylarginine increase, reduced dimethylarginine dimethylamine hydrolase enzyme activity, low-grade chronic systemic inflammation, hyperhomocysteinemia, oxidative stress, insulin resistance, alteration of calcium phosphorus metabolism, and early aging. In this review, we also examined the most important techniques useful for studying ED in humans, which are divided into indirect and direct methods. The direct study of coronary endothelial function is considered the gold standard technique to evaluate if ED is present. In addition to the discussion of the main pharmacological treatments useful to counteract ED in CKD patients (namely sodium-glucose cotransporter 2 inhibitors and mineralocorticoid receptor antagonist), we elucidate innovative non-pharmacological treatments that are successful in accompanying the pharmacological ones. Among them, the most important are the consumption of extra virgin olive oil with high intake of minor polar compounds, adherence to a plant-dominant, low-protein diet (LPD), an adaptive physical activity program and, finally, ketoanalogue administration in combination with the LPD or the very low-protein diet.

SGLT-2 inhibitors as novel treatments of multiple organ fibrosis

Fibrosis, a significant health issue linked to chronic inflammatory diseases, affects various organs and can lead to serious damage and loss of function. Despite the availability of some treatments, their limitations necessitate the development of new therapeutic options. Sodium-glucose cotransporter 2 inhibitors (SGLT2i), known for their glucose-lowering ability, have shown promise in offering protective effects against fibrosis in multiple organs through glucose-independent mechanisms. This review explores the anti-fibrotic potential of SGLT2i across different tissues, providing insights into their underlying mechanisms and highlighting recent research advancements. The evidence positions SGLT2i as a potential future treatments for fibrotic diseases.

SGLT2 inhibitors: from glucose-lowering to cardiovascular benefits

An increasing number of individuals are at high risk of type 2 diabetes (T2D) and its cardiovascular complications, including heart failure (HF), chronic kidney disease (CKD), and eventually premature death. The sodium-glucose co-transporter-2 (SGLT2) protein sits in the proximal tubule of human nephrons to regulate glucose reabsorption and its inhibition by gliflozins represents the cornerstone of contemporary T2D and HF management. Herein, we aim to provide an updated overview of the pleiotropy of gliflozins, provide mechanistic insights and delineate related cardiovascular (CV) benefits. By discussing contemporary evidence obtained in preclinical models and landmark randomized controlled trials, we move from bench to bedside across the broad spectrum of cardio- and cerebrovascular diseases. With landmark randomized controlled trials confirming a reduction in major adverse CV events (MACE; composite endpoint of CV death, non-fatal myocardial infarction, and non-fatal stroke), SGLT2 inhibitors strongly mitigate the risk for heart failure hospitalization in diabetics and non-diabetics alike while conferring renoprotection in specific patient populations. Along four major pathophysiological axes (i.e. at systemic, vascular, cardiac, and renal levels), we provide insights into the key mechanisms that may underlie their beneficial effects, including gliflozins' role in the modulation of inflammation, oxidative stress, cellular energy metabolism, and housekeeping mechanisms. We also discuss how this drug class controls hyperglycaemia, ketogenesis, natriuresis, and hyperuricaemia, collectively contributing to their pleiotropic effects. Finally, evolving data in the setting of cerebrovascular diseases and arrhythmias are presented and potential implications for future research and clinical practice are comprehensively reviewed.

Cardiovascular Disease Management With Sodium-Glucose Cotransporter-2 Inhibitors in Patients With Type 2 Diabetes: A Cardiology Primer

Patients with type 2 diabetes face an elevated risk of cardiovascular disease. This review centers on sodium-glucose cotransporter-2 (SGLT2) inhibitors, a class of drugs that, according to a growing body of evidence, may have major potential for managing cardiovascular disease in patients with type 2 diabetes. This review presents findings from multiple clinical trials suggesting that SGLT2 inhibitors can not only serve as preventive therapeutic agents but also play a role in the active management of heart failure. The discussion includes the mechanism of action of SGLT2 inhibitors, emphasizing that they enhance urinary glucose excretion, which could lead to improved glycemic control and contribute to metabolic shifts beneficial to cardiac function. Alongside these cardiometabolic effects, safety concerns and practical considerations for prescribing these agents are addressed, taking into account potential adverse effects such as genitourinary infections and diabetic ketoacidosis as well as the financial implications for patients. Despite these drawbacks, therapeutic indications for SGLT2 inhibitors continue to expand, including for kidney protection, although further research is necessary to fully understand the mechanisms driving the cardioprotective and kidney-protective effects of SGLT2 inhibitors. By synthesizing current knowledge, this review intends to inform and guide clinical decision-making, thereby enhancing cardiovascular disease outcomes in patients with type 2 diabetes.

A Study to Evaluate the Effect of Sodium-Glucose Co-transporter 2 (SGLT2) Inhibitors on Oxidative Stress Parameters in Type 2 Diabetes Mellitus Patients

Introduction Diabetes mellitus (DM) is a global health issue with 50 million diabetics currently residing in India. Hyperglycemia causes tissue damage due to mitochondrial overproduction of reactive oxygen species. Sodium-glucose cotransporter-2 (SGLT2) inhibitors (SGLT2i) have shown a decrease in oxidative stress by either amelioration of free-radical generation or potentiation of cellular antioxidative capacity in preclinical studies. However, there is a paucity of published clinical studies. Hence, this study was undertaken to evaluate the effect of co-administration of SGLT2i with other drugs on oxidative stress in type 2 DM (T2DM) patients. Methods A prospective, parallel, open-label study in T2DM patients attending endocrinology OPD was conducted for a period of 12 months. At the clinician's discretion, patients were grouped as SGLT2i as an add-on to standard drugs vs standard drugs alone. Blood samples were collected at baseline and at the end of 12 weeks to estimate malondialdehyde (MDA), nitric oxide (NO), and glutathione (GSH) levels. Secondary parameters - glycemic indices and lipid profile - were estimated every four weeks. Results A total of 32 patients were enrolled in the study (16 per group). There was a significant decrease in MDA (p < 0.05) and NO (p < 0.01) and a highly significant increase in GSH (p < 0.001) at 12 weeks from baseline in the SGLT2i group. A reduction in fasting blood sugar (FBS) and post-prandial blood sugar (PPBS) and a 0.56% difference in HbA1c were also noted in the SGLT2i group. Significant lowering of low-density lipoprotein (LDL, p < 0.05) and elevation in HDL levels (p < 0.05) from baseline was seen in the SGLT2i group.  Conclusion Co-administration of SGLT2i with antidiabetic drugs demonstrated a significant effect in improving oxidative stress biomarkers and glycemic and lipid profiles among T2DM patients.

Oxidative stress and the role of redox signalling in chronic kidney disease

Chronic kidney disease (CKD) is a major public health concern, underscoring a need to identify pathogenic mechanisms and potential therapeutic targets. Reactive oxygen species (ROS) are derivatives of oxygen molecules that are generated during aerobic metabolism and are involved in a variety of cellular functions that are governed by redox conditions. Low levels of ROS are required for diverse processes, including intracellular signal transduction, metabolism, immune and hypoxic responses, and transcriptional regulation. However, excess ROS can be pathological, and contribute to the development and progression of chronic diseases. Despite evidence linking elevated levels of ROS to CKD development and progression, the use of low-molecular-weight antioxidants to remove ROS has not been successful in preventing or slowing disease progression. More recent advances have enabled evaluation of the molecular interactions between specific ROS and their targets in redox signalling pathways. Such studies may pave the way for the development of sophisticated treatments that allow the selective control of specific ROS-mediated signalling pathways.

SGLT2 inhibitor improves the prognosis of patients with coronary heart disease and prevents in-stent restenosis

Coronary heart disease is a narrowing or obstruction of the vascular cavity caused by atherosclerosis of the coronary arteries, which leads to myocardial ischemia and hypoxia. At present, percutaneous coronary intervention (PCI) is an effective treatment for coronary atherosclerotic heart disease. Restenosis is the main limiting factor of the long-term success of PCI, and it is also a difficult problem in the field of intervention. Sodium-glucose cotransporter 2 (SGLT2) inhibitor is a new oral glucose-lowering agent used in the treatment of diabetes in recent years. Recent studies have shown that SGLT2 inhibitors can effectively improve the prognosis of patients after PCI and reduce the occurrence of restenosis. This review provides an overview of the clinical studies and mechanisms of SGLT2 inhibitors in the prevention of restenosis, providing a new option for improving the clinical prognosis of patients after PCI.

SGLT2 Inhibition in Heart Failure: Clues to Cardiac Effects?

Following the publication of several landmark clinical trials such as dapagliflozin in patients with heart failure and reduced ejection fraction, dapagliflozin evaluation to improve the lives of patients with preserved ejection fraction heart failure, and empagliflozin outcome trial in patients with chronic heart failure with preserved ejection fraction, sodium-glucose cotransport 2 inhibitors have been rapidly incorporated as a guideline-directed therapy in the treatment of heart failure. Moreover, their benefits appear to extend across the spectrum of left ventricular dysfunction which in some respects, can be seen as the holy grail of heart failure pharmacotherapy. Despite its plethora of proven cardioprotective benefits, the mechanisms by which it exerts these effects remain poorly understood, however, it is clear that these extend beyond that of promotion of glycosuria and natriuresis. Several hypotheses have emerged over the years including modification of cardiovascular risk profile via weight reduction, improved glucose homeostasis, blood pressure control, and natriuretic effect; however, these mechanisms do not fully explain the potent effects of the drug demonstrated in large-scale randomized trials. Other mechanisms may be at play, specifically the down-regulation of inflammatory pathways, improved myocardial sodium homeostasis, modulation of profibrotic pathways, and activation of nutrient deprivation signaling pathways promoting autophagic flux. This review seeks to summarize the cardioprotective benefits demonstrated in major clinical trials and provide a succinct review of the current theories of mechanisms of action, based on the most recent evidence derived from both clinical and laboratory data.

Neuraminidase inhibition improves endothelial function in diabetic mice

Neuraminidases cleave sialic acids from glycocalyx structures and plasma neuraminidase activity is elevated in type 2 diabetes (T2D). Therefore, we hypothesize circulating neuraminidase degrades the endothelial glycocalyx and diminishes flow-mediated dilation (FMD), whereas its inhibition restores shear mechanosensation and endothelial function in T2D settings. We found that compared with controls, subjects with T2D have higher plasma neuraminidase activity, reduced plasma nitrite concentrations, and diminished FMD. Ex vivo and in vivo neuraminidase exposure diminished FMD and reduced endothelial glycocalyx presence in mouse arteries. In cultured endothelial cells, neuraminidase reduced glycocalyx coverage. Inhalation of the neuraminidase inhibitor, zanamivir, reduced plasma neuraminidase activity, enhanced endothelial glycocalyx length, and improved FMD in diabetic mice. In humans, a single-arm trial (NCT04867707) of zanamivir inhalation did not reduce plasma neuraminidase activity, improved glycocalyx length, or enhanced FMD. Although zanamivir plasma concentrations in mice reached 225.8 ± 22.0 ng/mL, in humans were only 40.0 ± 7.2 ng/mL. These results highlight the potential of neuraminidase inhibition for ameliorating endothelial dysfunction in T2D and suggest the current Food and Drug Administration-approved inhaled dosage of zanamivir is insufficient to achieve desired outcomes in humans.NEW & NOTEWORTHY This work identifies neuraminidase as a key mediator of endothelial dysfunction in type 2 diabetes that may serve as a biomarker for impaired endothelial function and predictive of development and progression of cardiovascular pathologies associated with type 2 diabetes (T2D). Data show that intervention with the neuraminidase inhibitor zanamivir at effective plasma concentrations may represent a novel pharmacological strategy for restoring the glycocalyx and ameliorating endothelial dysfunction.

Empagliflozin Reverses Oxidized LDL-Induced RECK Suppression, Cardiotrophin-1 Expression, MMP Activation, and Human Aortic Smooth Muscle Cell Proliferation and Migration

Persistent oxidative stress and inflammation contribute causally to smooth muscle cell (SMC) proliferation and migration, the characteristic features of vascular proliferative diseases. Oxidatively modified low-density lipoproteins (OxLDL) elevate oxidative stress levels, inflammatory responses, and matrix metallopeptidase (MMP) activation, resulting ultimately in SMC migration, proliferation, and phenotype change. Reversion-inducing cysteine-rich protein with Kazal motifs (RECK) is a membrane-anchored MMP inhibitor. Empagliflozin is an SGLT2 inhibitor and exerts pleiotropic cardiovascular protective effects, including antioxidant and anti-inflammatory effects. Here, we investigated (i) whether OxLDL regulates RECK expression, (ii) whether ectopic expression of RECK reverses OxLDL-induced SMC migration and proliferation, and (iii) whether pretreatment with empagliflozin reverses OxLDL-induced RECK suppression, MMP activation, and SMC migration, proliferation, and differentiation. Indeed, results show that OxLDL at pathophysiological concentration promotes SMC migration and proliferation via NF-κB/miR-30b-dependent RECK suppression. Moreover, OxLDL changed the SMC phenotype to a more pro-inflammatory type, and this effect is blunted by RECK overexpression. Further, treatment with empagliflozin reversed OxLDL-induced miR-30b induction, RECK suppression, MMP activation, SMC migration, proliferation, and proinflammatory phenotype changes. OxLDL-induced cardiotrophin (CT)-1 expression and CT-1 stimulated SMC proliferation and migration in part via leukemia inhibitory factor receptor (LIFR) and glycoprotein 130 (gp130). Ectopic expression of RECK inhibited these effects by physically associating with LIFR and gp130, as evidenced by immunoprecipitation/immunoblotting and double immunofluorescence. Importantly, empagliflozin inhibited CT-1-induced mitogenic and migratory effects. Together, these results suggest the therapeutic potential of sustaining RECK expression or empagliflozin in vascular diseases characterized by SMC proliferation and migration.

Empagliflozin decreases ageing-associated arterial stiffening and vascular fibrosis under normoglycemic conditions

Arterial stiffness is a hallmark of vascular ageing and results in increased blood flow pulsatility to the periphery, damaging end-organs such as the heart, kidneys and brain. Treating or "reversing" arterial stiffness has therefore become a central target in the field of vascular ageing. SGLT2 inhibitors, initially developed in the context of type 2 diabetes mellitus, have become a cornerstone of heart failure treatment. Additionally, effects on the vasculature have been reported. Here, we demonstrate that treatment with the SGLT2 inhibitor empagliflozin (7 weeks, 15 mg/kg/day) decreased ageing-induced arterial stiffness of the aorta in old mice with normal blood glucose levels. However, no universal mechanism was identified. While empagliflozin reduced the ageing-associated increase in collagen type I in the medial layer of the abdominal infrarenal aorta and decreased medial TGF-β deposition, this was not observed in the thoracic descending aorta. Moreover, empagliflozin was not able to prevent elastin fragmentation. In conclusion, empagliflozin decreased arterial stiffness in aged mice, indicating that SGLT2 inhibition could be a valuable strategy in mitigating vascular ageing. Further research is warranted to unravel the underlying, possibly region-specific, mechanisms.

Outcomes Associated with Sodium-Glucose Cotransporter-2 Inhibitor Use in Acute Heart Failure Hospitalizations Complicated by AKI

Key Points

In a multicenter retrospective cohort study of adults hospitalized with acute heart failure, exposure to sodium-glucose cotransporter-2 inhibitor during AKI was associated with lower risk of 30-day mortality. Exposure to sodium-glucose cotransporter-2 inhibitor during acute heart failure–associated AKI was associated with no difference in time to renal recovery. The findings were reproducible in inverse probability-weighted analysis.

Background

Although sodium-glucose cotransporter-2 inhibitor (SGLT2i) use during acute heart failure (AHF) hospitalizations is associated with symptomatic improvement, reduction in rehospitalizations, and mortality, these medications are often withheld during AKI because of concerns about worsening GFR. We aimed to investigate the safety of SGLT2i exposure during AKI among patients hospitalized with AHF. We hypothesized that SGLT2i exposure would not worsen mortality but may prolong return of creatinine to baseline.

Methods

This was a retrospective study of adults hospitalized across five Yale New Haven Health System hospitals between January 2020 and May 2022 with AHF complicated by Kidney Disease Improving Global Outcomes–defined AKI. Patients with stage 5 CKD and those with potential contraindications to SGLT2i were excluded. We tested the association of SGLT2i use with kidney function recovery at 14 days and death at 30 days using time-varying, multivariable Cox-regression analyses.

Results

Of 3305 individuals hospitalized with AHF and AKI, 356 received SGLT2i after AKI diagnosis either as initiation or continuation. The rate of renal recovery was not significantly different among those exposed and unexposed to SGLT2i after AKI (adjusted hazard ratio, 0.94; 95% confidence interval, 0.79 to 1.11; P = 0.46). SGLT2i exposure was associated with lower risk of 30-day mortality (adjusted hazard ratio, 0.45; 95% confidence interval, 0.23 to 0.87; P = 0.02). Sensitivity analyses using an inverse probability-weighted time-varying Cox regression analysis and using alternate definitions of AHF with different NT-proBNP cutoffs yielded similar results. Rates of renal recovery were similar between the exposed and unexposed cohorts regardless of the proximity of SGLT2i exposure to AKI diagnosis.

Conclusion

In adults experiencing AHF-associated AKI, exposure to SGLT2i was associated with decreased mortality and no delay in renal recovery. Prospective studies are needed to elucidate the effect of SGLT2i exposure during AKI, particularly during heart failure hospitalizations.

Comparative Safety Analysis of Empagliflozin in Type 2 Diabetes Mellitus Patients with Chronic Kidney Disease versus Normal Kidney Function: A Nationwide Cohort Study in Korea

BACKGROUND

Empagliflozin has been shown to reduce cardiovascular morbidity and mortality in patients with type 2 diabetes. Various research on its efficacy in patients with chronic kidney disease (CKD) have been actively conducted. So far, few studies have investigated the safety of these adverse effects specifically in Asians with CKD. We aim to address these safety concerns on a patient population of Asian CKD patients using real-world data.

METHODS

We conducted a retrospective cohort study using health insurance data from the Korean Health Insurance Review & Assessment Service and compared safety outcomes between empagliflozin and sitagliptin in 26,347 CKD patients diagnosed with diabetes. Adverse outcomes, including major adverse cardiac events (MACEs), all-cause mortality, myocardial infarction (MI), stroke, and hospitalization for heart failure (HHF), among others, were assessed.

RESULTS

Among a 1:1 matched cohort (6170 on empagliflozin, 6170 on sitagliptin), empagliflozin was associated with a significant reduction in MACEs, all-cause mortality, MI, hospitalization for unstable angina, coronary revascularization, HHF, hypoglycemic events, and urinary tract infections, but increased the risk of genital tract infections. No significant changes were observed for transient ischemic attack, acute kidney injury, volume depletion, diabetic ketoacidosis, thromboembolic events, and fractures.

CONCLUSIONS

The usage of empagliflozin in diabetic CKD patients shows a significant reduction in many adverse outcomes compared to sitagliptin, but with an increased risk of genital tract infections. These findings provide evidence for future clinical decision-making around the use of empagliflozin in Asian CKD patients.

Renal intrinsic cells remodeling in diabetic kidney disease and the regulatory effects of SGLT2 Inhibitors

Diabetic kidney disease (DKD) is a prevalent complication of diabetes and a major secondary factor leading to end-stage renal disease. The kidney, a vital organ, is composed of a heterogeneous group of intrinsic cells, including glomerular endothelial cells, podocytes, mesangial cells, tubular epithelial cells, and interstitial fibroblasts. In the context of DKD, hyperglycemia elicits direct or indirect injury to these intrinsic cells, leading to their structural and functional changes, such as cell proliferation, apoptosis, and transdifferentiation. The dynamic remodeling of intrinsic cells represents an adaptive response to stimulus during the pathogenesis of diabetic kidney disease. However, the persistent stimulus may trigger an irreversible remodeling, leading to fibrosis and functional deterioration of the kidney. Sodium-glucose cotransporter 2 (SGLT2) inhibitors, a new class of hypoglycemic drugs, exhibit efficacy in reducing blood glucose levels by curtailing renal tubular glucose reabsorption. Furthermore, SGLT2 inhibitors have been shown to modulate intrinsic cell remodeling in the kidney, ameliorate kidney structure and function, and decelerate DKD progression. This review will elaborate on the intrinsic cell remodeling in DKD and the underlying mechanism of SGLT2 inhibitors in modulating it from the perspective of the renal intrinsic cell, providing insights into the pathogenesis of DKD and the renal protective action of SGLT2 inhibitors.

Dapagliflozin prevents oxidative stress-induced endothelial dysfunction via sirtuin 1 activation

Recent studies have demonstrated that dapagliflozin, a sodium-glucose cotransporter type 2 (SGLT2) inhibitor, prevents endothelial dysfunction; however, direct effects of dapagliflozin on the endothelium under oxidative stress and the underlying mechanism of action are not completely understood. This study aimed to define the role and related mechanisms of dapagliflozin in hydrogen peroxide (H2O2)-induced endothelial dysfunction. The endothelium-dependent vasorelaxation effect of dapagliflozin was assessed in an organ bath study. Endothelial dysfunction was assessed using protein expression level and phosphorylation of endothelial nitric oxide synthase (eNOS), nitric oxide (NO), reactive oxygen species (ROS), senescence-associated beta-galactosidase (SA-β-gal) activity, and senescence marker proteins (p21, p53). Co-immunoprecipitation and protein acetylation were performed to detect protein interactions. Dapagliflozin exerted a direct vasorelaxant effect in the aortic rings of C57BL/6 J mice. Furthermore, there was a significant improvement in endothelium-dependent vasorelaxation in dapagliflozin-treated diabetic mice compared to vehicle controls. Moreover, intracellular ROS levels and ONOO- levels, increased by H2O2, were reduced by dapagliflozin. Importantly, dapagliflozin inhibited H2O2-induced senescence in the human umbilical vein endothelial cells (HUVECs), as indicated by reduced SA-β-gal, p21, and p53. Mechanistically, dapagliflozin reversed the H2O2-mediated inhibition of eNOS serine phosphorylation and sirtuin 1 (SIRT1) expression in endothelial cells. In particular, SIRT1-mediated eNOS deacetylation is reportedly involved in dapagliflozin-enhanced eNOS activity. These findings indicate that dapagliflozin ameliorates endothelial dysfunction by restoring eNOS activity, restoring NO bioavailability, and reducing ROS generation via SIRT1 activation in oxidative stress-stimulated endothelial cells.

A systematic review on renal effects of SGLT2 inhibitors in rodent models of diabetic nephropathy

We have performed a systematic review of studies reporting on the renal effects of SGLT2 inhibitors in rodent models of diabetes. In 105 studies, SGLT2 inhibitors improved not only the glycemic control but also various aspects of renal function in most cases. These nephroprotective effects were similarly reported whether treatment with the SGLT2 inhibitor started concomitant with the onset of diabetes (within 1 week), early after onset (1-4 weeks) or after nephropathy had developed (>4 weeks after onset) with the latter probably having the greatest translational value. They were observed across various animal models of type 1 and type 2 diabetes/obesity (4 and 23 models, respectively), although studies in the type 2 diabetes model of db/db mice more often had negative data than in other models. Among possibly underlying pathophysiological mechanisms of nephroprotection, treatment with SGLT2 inhibitors had beneficial effects on lipid metabolism, blood pressure, glomerulosclerosis as well as renal tubular fibrosis, apoptosis, oxidative stress, and inflammation. These pathomechanisms highly influence atherosclerosis and renal health, which are two major factors that lead to an enhanced mortality in patients with diabetes and/or chronic kidney disease. Interestingly, renal SGLT2 inhibitor effects did not always correlate with those on glucose homeostasis, particularly in a limited number of direct comparative studies with other anti-diabetic treatments, indicating that nephroprotection may at least partly occur by mechanisms other than improving glycemic control. Our analyses did not provide evidence for different nephroprotective efficacy between SGLT2 inhibitors. Importantly, only four of 105 studies reported on female animals, and none provided direct comparative data between sexes. We conclude that more data on female animals and more direct comparative studies with other anti-diabetic compounds and combinations of treatments are needed.

SGLT2 inhibitors: an evidence-based update on cardiovascular implications

INTRODUCTION

Sodium Glucose co-Transporter 2 (SGLT2) inhibitors (also known as 'gliflozins') represent a cornerstone to treat diabetes mellitus. Moreover, recent randomized clinical trials have demonstrated important cardioprotective effects of gliflozins, independent of the presence of diabetes. Herein, we summarize the recent therapeutic progress in the cardiovascular field obtained with SGLT2 inhibitors.

AREA COVERED

We critically examine the rationale and results of recent clinical studies examining the effects of SGLT2 inhibitors on cardiovascular outcomes, along with a brief overview of the main ongoing trials that have been designed in order to answer the many pending questions in the field of gliflozins and cardiovascular disease.

EXPERT OPINION

The favorable results of several clinical trials have broadened the therapeutic scenario for SGLT2 inhibitors, opening, at the same time, new challenges. Additionally, recent preclinical findings have evidenced off-target effects of SGLT2 inhibitors.

Brain Endothelial Cells Play a Central Role in the Development of Enlarged Perivascular Spaces in the Metabolic Syndrome

Brain capillary endothelial cell(s) (BECs) have numerous functions, including their semipermeable interface-barrier (transfer and diffusion of solutes), trophic (metabolic homeostasis), tonic (vascular hemodynamics), and trafficking (vascular permeability, coagulation, and leukocyte extravasation) functions to provide brain homeostasis. BECs also serve as the brain's sentinel cell of the innate immune system and are capable of antigen presentation. In metabolic syndrome (MetS), there are two regions resulting in the proinflammatory signaling of BECs, namely visceral adipose tissue depots supplying excessive peripheral cytokines/chemokines (pCCs) and gut microbiota dysbiotic regions supplying excessive soluble lipopolysaccharide (sLPS), small LPS-enriched extracellular vesicle exosomes (lpsEVexos), and pCCs. This dual signaling of BECs at their receptor sites results in BEC activation and dysfunction (BECact/dys) and neuroinflammation. sLPS and lpsEVexos signal BECs' toll-like receptor 4, which then signals translocated nuclear factor kappa B (NFkB). Translocated NFkB promotes the synthesis and secretion of BEC proinflammatory cytokines and chemokines. Specifically, the chemokine CCL5 (RANTES) is capable of attracting microglia cells to BECs. BEC neuroinflammation activates perivascular space(s) (PVS) resident macrophages. Excessive phagocytosis by reactive resident PVS macrophages results in a stagnation-like obstruction, which along with increased capillary permeability due to BECact/dys could expand the fluid volume within the PVS to result in enlarged PVS (EPVS). Importantly, this remodeling may result in pre- and post-capillary EPVS that would contribute to their identification on T2-weighted MRI, which are considered to be biomarkers for cerebral small vessel disease.

The Role of Cardiac Fibrosis in Diabetic Cardiomyopathy: From Pathophysiology to Clinical Diagnostic Tools

Diabetes mellitus (DM) is a chronic metabolic disorder characterized by hyperglycemia due to inadequate insulin secretion, resistance, or both. The cardiovascular complications of DM are the leading cause of morbidity and mortality in diabetic patients. There are three major types of pathophysiologic cardiac remodeling including coronary artery atherosclerosis, cardiac autonomic neuropathy, and DM cardiomyopathy in patients with DM. DM cardiomyopathy is a distinct cardiomyopathy characterized by myocardial dysfunction in the absence of coronary artery disease, hypertension, and valvular heart disease. Cardiac fibrosis, defined as the excessive deposition of extracellular matrix (ECM) proteins, is a hallmark of DM cardiomyopathy. The pathophysiology of cardiac fibrosis in DM cardiomyopathy is complex and involves multiple cellular and molecular mechanisms. Cardiac fibrosis contributes to the development of heart failure with preserved ejection fraction (HFpEF), which increases mortality and the incidence of hospitalizations. As medical technology advances, the severity of cardiac fibrosis in DM cardiomyopathy can be evaluated by non-invasive imaging modalities such as echocardiography, heart computed tomography (CT), cardiac magnetic resonance imaging (MRI), and nuclear imaging. In this review article, we will discuss the pathophysiology of cardiac fibrosis in DM cardiomyopathy, non-invasive imaging modalities to evaluate the severity of cardiac fibrosis, and therapeutic strategies for DM cardiomyopathy.

Overview and New Insights into the Metabolic Syndrome: Risk Factors and Emerging Variables in the Development of Type 2 Diabetes and Cerebrocardiovascular Disease

Metabolic syndrome (MetS) is considered a metabolic disorder that has been steadily increasing globally and seems to parallel the increasing prevalence of obesity. It consists of a cluster of risk factors which traditionally includes obesity and hyperlipidemia, hyperinsulinemia, hypertension, and hyperglycemia. These four core risk factors are associated with insulin resistance (IR) and, importantly, the MetS is known to increase the risk for developing cerebrocardiovascular disease and type 2 diabetes mellitus. The MetS had its early origins in IR and syndrome X. It has undergone numerous name changes, with additional risk factors and variables being added over the years; however, it has remained as the MetS worldwide for the past three decades. This overview continues to add novel insights to the MetS and suggests that leptin resistance with hyperleptinemia, aberrant mitochondrial stress and reactive oxygen species (ROS), impaired folate-mediated one-carbon metabolism with hyperhomocysteinemia, vascular stiffening, microalbuminuria, and visceral adipose tissues extracellular vesicle exosomes be added to the list of associated variables. Notably, the role of a dysfunctional and activated endothelium and deficient nitric oxide bioavailability along with a dysfunctional and attenuated endothelial glycocalyx, vascular inflammation, systemic metainflammation, and the important role of ROS and reactive species interactome are discussed. With new insights and knowledge regarding the MetS comes the possibility of new findings through further research.

Ultrastructural Remodeling of the Blood-Brain Barrier and Neurovascular Unit by Lipopolysaccharide-Induced Neuroinflammation

The blood-brain barrier (BBB) is an interface primarily comprised of brain endothelial cells (BECs), separating the central nervous system (CNS) from the systemic circulation while carefully regulating the transport of molecules and inflammatory cells, and maintaining the required steady-state environment. Inflammation modulates many BBB functions, but the ultrastructural cytoarchitectural changes of the BBB with inflammation are understudied. Inflammation was induced in male 8-10-week-old CD-1 mice with intraperitoneal lipopolysaccharide (LPS), using a regimen (3 mg/kg at 0, 6, and 24 h) that caused robust BBB disruption but had minimal lethality at the study timepoint of 28 h. Perfusion-fixed brains were collected and the frontal cortical layer III regions were analyzed using a transmission electron microscopy (TEM). The LPS-treated mice had pronounced ultrastructural remodeling changes in BECs that included plasma membrane ruffling, increased numbers of extracellular microvesicles, small exosome formation, aberrant BEC mitochondria, increased BEC transcytosis, while tight junctions appeared to be unaltered. Aberrant pericytes were contracted with rounded nuclei and a loss of their elongated cytoplasmic processes. Surveilling microglial cells were attracted to the neurovascular unit (NVU) of BECs, and astrocyte detachment and separation were associated with the formation of a perivascular space and pericapillary edema. The LPS treatment resulted in numerous ultrastructural aberrant remodeling changes to the neurovascular unit's BECs, microglia, pericytes, and astrocytes. In summary, a disturbance of the NVU morphology is a consequence of LPS treatment.

Bibliometric and visualized analysis of sodium-Glucose cotransporter 2 inhibitors

Background: Sodium-glucose cotransporter 2 inhibitors have proved to be extremely effective and reliable in reducing hyperglycemia, and have also been used for the treatment of cardiovascular and renal disease in patients with or without type 2 diabetes. Thousands of research articles on SGLT2 inhibitors have been published in the past, but few bibliometric analyses have systematically been studied this field. We aimed to visualize the global research hotspots and trends of SGLT2 inhibitors using a bibliometric analysis to provide new evidence and ideas for researchers and clinicians in this field. Methods: We retrieved publications from Science Citation Index Expanded of Web of Science Core Collection in 2004-2022 on 1 July 2022. Microsoft Excel, CiteSpace and VOSviewer were employed to collect publication data, analyze publication trends, and visualize relevant results. Results: We identified 4,419 original research articles on SGLT2 inhibitors published between 2004 and the first half of 2022. Global SGLT2 inhibitors-related research increased rapidly from 2004 to 2022, especially recently. United States made the greatest contribution to the topic, with (1,629, 36.86%) publications and citations (88,892). AstraZeneca was the most prolific institutions (272, 6.16%). Heerspink HJL published the most related articles (98), whereas Zinman B was cited the most frequently (1,784 citations). Diabetes Obesity and Metabolism was the journal with the most studies (406, 9.19%), and The New England Journal of Medicine was the most commonly cited journal (11,617 citations), with nine of the top 10 co-cited references published in this journal. The emerging keywords "heart failure," "diabetic cardiomyopathy," "ejection fraction," "mortality," "biomarker," "fibrosis," "ampk," and "guideline" appeared the most recently as research frontiers. Conclusion: United States is the leader in SGLT2 inhibitor research. Recently, the research on SGLT2 inhibitors has focused on clinical trials, related mechanisms, and therapy. In the future, the research on SGLT2 inhibitors will delve into molecular mechanisms, especially those related to fibrosis and AMPK, revealing the link between SGLT2 inhibitors and heart failure and diabetic cardiomyopathy will be the next research hotspot.

Blood Pressure and Dapagliflozin in Heart Failure With Mildly Reduced or Preserved Ejection Fraction: DELIVER

BACKGROUND

Optimizing systolic blood pressure (SBP) in heart failure (HF) with preserved ejection fraction carries a Class I recommendation but with limited evidence. Sodium-glucose cotransporter 2 (SGLT2) inhibitors have antihypertensive effects across cardiovascular disease.

OBJECTIVES

The authors examined the interplay between SBP and treatment effects of dapagliflozin on SBP and cardiovascular outcomes.

METHODS

The authors analyzed 6,263 DELIVER (Dapagliflozin Evaluation to Improve the LIVEs of Patients With PReserved Ejection Fraction Heart Failure) participants and related baseline and mean achieved SBP categories (<120, 120-129, 130-139, ≥140 mm Hg) to the primary outcome (cardiovascular death or worsening HF), secondary outcomes, and safety events. They analyzed whether the blood pressure-lowering effects of dapagliflozin accounted for its treatment effects by adjusting for the change in SBP from baseline to 1 month.

RESULTS

The average age was 72 ± 10 years and 44% were women. SBP <120 mm Hg was associated with higher HF and mortality events, although amputation and stroke risk increased with higher SBP. Dapagliflozin reduced SBP by 1.8 (95% CI: 1.1-2.5) mm Hg compared with placebo at 1 month. The treatment effect of dapagliflozin on the primary outcome and Kansas City Cardiomyopathy Questionnaire total symptom score was consistent across SBP (interaction P = 0.15 and P = 0.98, respectively). Adverse events between arms were similar across SBP categories. The treatment effect was not accounted for by reducing blood pressure.

CONCLUSIONS

In DELIVER, risk by SBP was augmented in the lowest and highest categories and varied by endpoint examined. Dapagliflozin modestly decreased SBP compared with placebo. Dapagliflozin was similarly efficacious and safe across the range of baseline SBP. The beneficial effects of dapagliflozin were not accounted for the changes in SBP. (Dapagliflozin Evaluation to Improve the LIVEs of Patients With PReserved Ejection Fraction Heart Failure [DELIVER]; NCT03619213).

Favorable effect of renal denervation on elevated renal vascular resistance in patients with resistant hypertension and type 2 diabetes mellitus

Objective

To assess the effect of renal denervation (RDN) on renal vascular resistance and renal function in patients with drug-resistant hypertension (HTN) and type 2 diabetes mellitus (T2DM).

Materials and methods

Fifty-nine patients (mean age 60.3 ± 7.9 years, 25 men) with resistant HTN [mean 24-h ambulatory blood pressure (BP) 158.0 ± 16.3/82.5 ± 12.7 mmHg, systolic/diastolic] and T2DM (mean HbA1c 7.5 ± 1.5%) were included in the single-arm prospective study and underwent RDN. Renal resistive index (RRI) derived from ultrasound Doppler; estimated glomerular filtration rate (Chronic Kidney Disease Epidemiology Collaboration formula), office and 24-h ambulatory BP were measured at baseline, 6, and 12 months after RDN to evaluate the respective changes in renal vascular resistance, renal function, and BP during treatment.

Results

Forty-three patients completed 12 months follow-up. The RRI changed depending on the baseline value. Specifically, the RRI decreased significantly in patients with elevated baseline RRI values ≥ 0.7 {n = 23; -0.024 [95% confidence interval (CI): -0.046, -0.002], p = 0.035} and did not change in those with baseline RRI < 0.7 [n = 36; 0.024 (95% CI: -0.002, 0.050), p = 0.069]. No significant change was observed in eGFR whereas BP was significantly reduced at 12 months after RDN by -10.9 (95% CI: -16.7, -5.0)/-5.5 (95% CI: -8.7, -2.4) mmHg, systolic/diastolic. No relationship was found between the changes in RRI and BP.

Conclusion

Our study shows that RDN can decrease elevated renal vascular resistance (RRI > 0.7) and stabilize kidney function in patients with RHTN and T2DM independently of its BP-lowering effect.

SGLT2 Inhibitors: New Hope for the Treatment of Acute Myocardial Infarction?

Among all of the new antidiabetic drugs, an increasing number of studies have evaluated the relationship between the sodium-glucose cotransporter 2 inhibitors (SGLT2i) and acute myocardial infarction (AMI). Since SGLT2i like empagliflozin, canagliflozin, and recently, dapagliflozin have shown impressive positive effects in patients with chronic heart failure with reduced ejection fraction (HFrEF), it has increased research interest to explore the cardiac molecular mechanisms underlying the clinical benefits and attracted more attention to the effects of SGLT2i on a series of cardiovascular events. Experimental and clinical data on SGLT2i treatment after AMI is limited. This is a review of the clinical and preclinical effects of SGLT2i, focusing on available data on the effects of SGLT2i in AMI patients with a brief overview of ongoing trials.

Empagliflozin ameliorates type 2 diabetes mellitus-related diabetic nephropathy via altering the gut microbiota

BACKGROUND

The dysregulation of gut microbiota can be found in patients with type 2 diabetes mellitus (T2DM)-related diabetic nephropathy (DN). Inhibitors of sodium-glucose co-transporter 2 (SGLT2) were reported to affect gut microbiota. This study aimed to identify whether empagliflozin (EMPA) attenuated DN via regulating gut microbiota.

MATERIALS AND METHODS

The high-fat diet (HFD) combining streptozocin (STZ) injection was performed to induce DN in mice. The therapeutic effects of EMPA were observed by staining of renal tissues and urine albumin/creatinine ratio (UACR). Mouse feces were collected for 16S rRNA sequencing. Fecal short-chain fatty acids (SCFAs) and fecal and serum lipopolysaccharide (LPS) were determined. An antibiotic-ablated model was established to confirm the role of the gut microbiota in the actions of EMPA.

RESULTS

EMPA reduced the elevation of blood glucose and UACR caused by HFD/STZ. It inhibited the thickening of the colonic crypt and restored goblet cells and the expressions of ZO-1 and Occludin. The 16S rRNA sequencing showed that the diversity of gut microbiota was reduced after HFD/STZ treatment, while it was restored after EMPA treatment. The LPS-producing bacteria, Oscillibacter, and the SCFA-producing bacteria, Bateroid and Odoribacter, were changed after EMPA administration. The therapeutic effects of EMPA on ABX-treated mice were reduced. Meanwhile, the level of fecal SCFAs was decreased, while the levels of fecal and serum LPS were elevated, in T2DM mice, and they were negated by the administration of EMPA.

CONCLUSION

EMPA ameliorates T2DM-related DN via altering the gut microbiota, especially reducing LPS-producing bacteria and increasing SCFA-producing bacteria.

From Diabetes Care to Heart Failure Management: A Potential Therapeutic Approach Combining SGLT2 Inhibitors and Plant Extracts

Diabetes is a complex chronic disease, and among the affected patients, cardiovascular disease (CVD)is the most common cause of death. Consequently, the evidence for the cardiovascular benefit of glycaemic control may reduce long-term CVD rates. Over the years, multiple pharmacological approaches aimed at controlling blood glucose levels were unable to significantly reduce diabetes-related cardiovascular events. In this view, a therapeutic strategy combining SGLT2 inhibitors and plant extracts might represent a promising solution. Indeed, countering the main cardiometabolic risk factor using plant extracts could potentiate the cardioprotective action of SGLT2 inhibitors. This review highlights the main molecular mechanisms underlying these beneficial effects that could contribute to the better management of diabetic patients.

Effects of dapagliflozin on volume status and systemic haemodynamics in patients with chronic kidney disease without diabetes: Results from DAPASALT and DIAMOND

AIMS

To assess the effect of sodium-glucose cotransporter-2 inhibitor dapagliflozin on natriuresis, blood pressure (BP) and volume status in patients with chronic kidney disease (CKD) without diabetes.

MATERIALS AND METHODS

We performed a mechanistic open-label study (DAPASALT) to evaluate the effects of dapagliflozin on 24-hour sodium excretion, 24-hour BP, extracellular volume, and markers of volume status during a standardized sodium diet (150 mmol/d) in six patients with CKD. In parallel, in a placebo-controlled double-blind crossover trial (DIAMOND), we determined the effects of 6 weeks of dapagliflozin on markers of volume status in 53 patients with CKD.

RESULTS

In DAPASALT (mean age 65 years, mean estimated glomerular filtration rate [eGFR] 39.4 mL/min/1.73 m² , median urine albumin:creatinine ratio [UACR] 111 mg/g), dapagliflozin did not change 24-hour sodium and volume excretion during 2 weeks of treatment. Dapagliflozin was associated with a modest increase in 24-hour glucose excretion on Day 4, which persisted at Day 14 and reversed to baseline after discontinuation. Mean 24-hour systolic BP decreased by -9.3 (95% confidence interval [CI] -19.1, 0.4) mmHg after 4 days and was sustained at Day 14 and at wash-out. Renin, angiotensin II, urinary aldosterone and copeptin levels increased from baseline. In DIAMOND (mean age 51 years, mean eGFR 59.0 mL/min/1.73 m² , median UACR 608 mg/g), compared to placebo, dapagliflozin increased plasma renin (38.5 [95% CI 7.4, 78.8]%), aldosterone (19.1 [95% CI -5.9, 50.8]%), and copeptin levels (7.3 [95% CI 0.1, 14.5] pmol/L).

CONCLUSIONS

During a standardized sodium diet, dapagliflozin decreased BP but did not increase 24-hour sodium and volume excretion. The lack of increased natriuresis and diuresis may be attributed to activation of intra-renal compensatory mechanisms to prevent excessive water loss.

Lack of renoprotective effects of targeting the endothelin A receptor and (or) sodium glucose transporter 2 in a mouse model of Type 2 diabetic kidney disease

Two recent clinical trials, using sodium glucose cotransporter (SGLT2) or endothelin-A receptor (ET-A) blocker, reported the first efficacious treatments in 18 years to slow progression of diabetic kidney disease (DKD). We hypothesized that combined inhibition of SGLT2 and ET-A receptor may confer greater protection against renal injury than either agent alone. Uninephrectomized male db/db mice were randomized to four groups: vehicle, SGLT2 inhibitor (dapagliflozin (dapa), 1 mg/kg/day), ET-A blocker (atrasentan (atra), 5 mg/kg/day), or dual treatment from 10 weeks until 22 weeks of age. At 10 weeks of age, no differences were observed in body weight, blood glucose or urinary albumin excretion among the four groups. At 16 and 22 weeks of age, body weight was lower and blood glucose levels higher in the vehicle and atra groups compared with dapa- and dual-treated groups. No notable differences were observed among the four groups in urinary albumin excretion at weeks 16 and 22. Histological analysis showed mild glomerulosclerosis and tubular injury (<5%) in all four groups with reduced glomerulosclerosis in the dual treatment group compared with vehicle. Individual or combined treatment with an SGLT2 inhibitor and (or) an ET-A antagonist did not confer renoprotective effects in this model.

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.

Sodium-glucose Cotransporter Type 2 Inhibitors: A New Insight into the Molecular Mechanisms of Diabetic Nephropathy

Diabetic nephropathy is one of the chronic microvascular complications of diabetes and is a leading cause of end-stage renal disease. Fortunately, clinical trials have demonstrated that sodium-glucose cotransporter type 2 inhibitors could decrease proteinuria and improve renal endpoints and are promising agents for the treatment of diabetic nephropathy. The renoprotective effects of sodium-glucose cotransporter type 2 inhibitors cannot be simply attributed to their advantages in aspects of metabolic benefits, such as glycemic control, lowering blood pressure, and control of serum uric acid, or improving hemodynamics associated with decreased glomerular filtration pressure. Some preclinical evidence suggests that sodium-glucose cotransporter type 2 inhibitors exert their renoprotective effects by multiple mechanisms, including attenuation of oxidative and endoplasmic reticulum stresses, anti-fibrosis and anti-inflammation, protection of podocytes, suppression of megalin function, improvement of renal hypoxia, restored mitochondrial dysfunction and autophagy, as well as inhibition of sodium-hydrogen exchanger 3. In the present study, the detailed molecular mechanisms of sodium-glucose cotransporter type 2 inhibitors with the actions of diabetic nephropathy were reviewed, with the purpose of providing the basis for drug selection for the treatment of diabetic nephropathy.

Impact of Sodium–Glucose Cotransporter 2 (SGLT2) Inhibitors on Arterial Stiffness and Vascular Aging—What Do We Know So Far? (A Narrative Review)

Vascular aging, early vascular aging or supernormal vascular aging are concepts used for estimating the cardiovascular risk at a certain age. From the famous line of Thomas Sydenham that “a man is as old as his arteries” to the present day, clinical studies in the field of molecular biology of the vasculature have demonstrated the active role of vascular endothelium in the onset of cardiovascular diseases. Arterial stiffness is an important cardiovascular risk factor associated with the occurrence of cardiovascular events and a high risk of morbidity and mortality, especially in the presence of diabetes. Sodium–glucose cotransporter 2 inhibitors decrease arterial stiffness and vascular resistance by decreasing endothelial cell activation, stimulating direct vasorelaxation and ameliorating endothelial dysfunction or expression of pro-atherogenic cells and molecules.

Mechanisms of Cardiorenal Protection With SGLT2 Inhibitors in Patients With T2DM Based on Network Pharmacology

Purpose

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have cardiorenal protective effects regardless of whether they are combined with type 2 diabetes mellitus, but their specific pharmacological mechanisms remain undetermined.

Materials and Methods

We used databases to obtain information on the disease targets of “Chronic Kidney Disease,” “Heart Failure,” and “Type 2 Diabetes Mellitus” as well as the targets of SGLT2 inhibitors. After screening the common targets, we used Cytoscape 3.8.2 software to construct SGLT2 inhibitors' regulatory network and protein-protein interaction network. The clusterProfiler R package was used to perform gene ontology functional analysis and Kyoto encyclopedia of genes and genomes pathway enrichment analyses on the target genes. Molecular docking was utilized to verify the relationship between SGLT2 inhibitors and core targets.

Results

Seven different SGLT2 inhibitors were found to have cardiorenal protective effects on 146 targets. The main mechanisms of action may be associated with lipid and atherosclerosis, MAPK signaling pathway, Rap1 signaling pathway, endocrine resistance, fluid shear stress, atherosclerosis, TNF signaling pathway, relaxin signaling pathway, neurotrophin signaling pathway, and AGEs-RAGE signaling pathway in diabetic complications were related. Docking of SGLT2 inhibitors with key targets such as GAPDH, MAPK3, MMP9, MAPK1, and NRAS revealed that these compounds bind to proteins spontaneously.

Conclusion

Based on pharmacological networks, this study elucidates the potential mechanisms of action of SGLT2 inhibitors from a systemic and holistic perspective. These key targets and pathways will provide new ideas for future studies on the pharmacological mechanisms of cardiorenal protection by SGLT2 inhibitors.

The Mighty Mitochondria Are Unifying Organelles and Metabolic Hubs in Multiple Organs of Obesity, Insulin Resistance, Metabolic Syndrome, and Type 2 Diabetes: An Observational Ultrastructure Study

Mitochondria (Mt) are essential cellular organelles for the production of energy and thermogenesis. Mt also serve a host of functions in addition to energy production, which include cell signaling, metabolism, cell death, and aging. Due to the central role of Mt in metabolism as metabolic hubs, there has been renewed interest in how Mt impact metabolic pathways and multiple pathologies. This review shares multiple observational ultrastructural findings in multiple cells and organs to depict aberrant mitochondrial (aMt) remodeling in pre-clinical rodent models. Further, it is intended to show how remodeling of Mt are associated with obesity, insulin resistance, metabolic syndrome (MetS), and type 2 diabetes mellitus (T2DM). Specifically, Mt remodeling in hypertensive and insulin-resistant lean models (Ren2 rat models), lean mice with streptozotocin-induced diabetes, obesity models including diet-induced obesity, genetic leptin-deficient ob/ob, and leptin receptor-deficient db/db diabetic mice are examined. Indeed, aMt dysfunction and damage have been implicated in multiple pathogenic diseases. Manipulation of Mt such as the induction of Mt biogenesis coupled with improvement of mitophagy machinery may be helpful to remove leaky damaged aMt in order to prevent the complications associated with the generation of superoxide-derived reactive oxygen species and the subsequent reactive species interactome. A better understanding of Mt remodeling may help to unlock many of the mysteries in obesity, insulin resistance, MetS, T2DM, and the associated complications of diabetic end-organ disease.

SGLT2 inhibition attenuates arterial dysfunction and decreases vascular F-actin content and expression of proteins associated with oxidative stress in aged mice

Aging of the vasculature is characterized by endothelial dysfunction and arterial stiffening, two key events in the pathogenesis of cardiovascular disease (CVD). Treatment with sodium glucose transporter 2 (SGLT2) inhibitors is now known to decrease cardiovascular morbidity and mortality in type 2 diabetes. However, whether SGLT2 inhibition attenuates vascular aging is unknown. We first confirmed in a cohort of adult subjects that aging is associated with impaired endothelial function and increased arterial stiffness and that these two variables are inversely correlated. Next, we investigated whether SGLT2 inhibition with empagliflozin (Empa) ameliorates endothelial dysfunction and reduces arterial stiffness in aged mice with confirmed vascular dysfunction. Specifically, we assessed mesenteric artery endothelial function and stiffness (via flow-mediated dilation and pressure myography mechanical responses, respectively) and aortic stiffness (in vivo via pulse wave velocity and ex vivo via atomic force microscopy) in Empa-treated (14 mg/kg/day for 6 weeks) and control 80-week-old C57BL/6 J male mice. We report that Empa-treated mice exhibited improved mesenteric endothelial function compared with control, in parallel with reduced mesenteric artery and aortic stiffness. Additionally, Empa-treated mice had greater vascular endothelial nitric oxide synthase activation, lower phosphorylated cofilin, and filamentous actin content, with downregulation of pathways involved in production of reactive oxygen species. Our findings demonstrate that Empa improves endothelial function and reduces arterial stiffness in a preclinical model of aging, making SGLT2 inhibition a potential therapeutic alternative to reduce the progression of CVD in older individuals.

Identification and Validation of miR-222-3p and miR-409-3p as Plasma Biomarkers in Gestational Diabetes Mellitus Sharing Validated Target Genes Involved in Metabolic Homeostasis

Gestational diabetes mellitus (GDM) causes both maternal and fetal adverse outcomes. The deregulation of microRNAs (miRNAs) in GDM suggests their involvement in GDM pathogenesis and complications. Exosomes are extracellular vesicles (EVs) of endosomal origin, released via exocytosis into the extracellular compartment. Through EVs, miRNAs are delivered in distant target cells and are able to affect gene expression. In this study, miRNA expression was analyzed to find new miRNAs that could improve GDM classification and molecular characterization. MiRNA were profiled in total plasma and EVs in GDM patients and normal glucose tolerance (NGT) women. Samples were collected at third trimester of gestation from two diabetes centers. MiRNA expression was profiled in a discovery cohort using the multiplexed NanoString nCounter Human v3 miRNA. Validation analysis was performed in a second independent cohort using RT-qPCR. A set of miRNAs resulted to be differentially expressed (DE) in total plasma and EVs in GDM. Among them, total plasma miR-222-3p and miR-409-3p were validated in the independent cohort. MiR-222-3p levels correlated with fasting plasma glucose (FPG) (p < 0.001) and birth weight (p = 0.012), whereas miR-409-3p expression correlated with FPG (p < 0.001) and inversely with gestational age (p = 0.001). The major validated target genes of the deregulated miRNAs were consistently linked to type 2 diabetes and GDM pathophysiology. MiR-222-3p and miR-409-3p are two circulating biomarkers that could improve GDM classification power and act in the context of the molecular events leading to the metabolic alterations observed in GDM.

Characteristics and molecular mechanisms through which SGLT2 inhibitors improve metabolic diseases: A mechanism review

Metabolic diseases, such as diabetes, gout and hyperlipidemia are global health challenges. Among them, diabetes has been extensively investigated. Type 2 diabetes mellitus (T2DM), which is characterized by hyperglycemia, is a complex metabolic disease that is associated with various metabolic disorders. The newly developed oral hypoglycemic agent, sodium-glucose cotransporter 2 (SGLT2) inhibitor, has been associated with glucose-lowering effects and it affects metabolism in various ways. However, the potential mechanisms of SGLT2 inhibitors in metabolic diseases have not fully reviewed. Many of the effects beyond glycemic control must be considered off-target effects. Therefore, we reviewed the effects of SGLT2 inhibition on metabolic diseases such as obesity, hypertension, hyperlipidemia, hyperuricemia, fatty liver disease, insulin resistance, osteoporosis and fractures. Moreover, we elucidated their molecular mechanisms to provide a theoretical basis for metabolic disease treatment.

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.

Old and Novel Therapeutic Approaches in the Management of Hyperglycemia, an Important Risk Factor for Atherosclerosis

Hyperglycemia is considered one of the main risk factors for atherosclerosis, since high glucose levels trigger multiple pathological processes, such as oxidative stress and hyperproduction of pro-inflammatory mediators, leading to endothelial dysfunction. In this context, recently approved drugs, such as glucagon-like-peptide-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT2i), could be considered a powerful tool for to reduce glucose concentration and cardiovascular risk. Interestingly, many patients with type 2 diabetes mellitus (T2DM) and insulin resistance have been found to be deficient in vitamin D. Recent studies pointed out the unfavorable prognostic values of T2DM and vitamin D deficiency in patients with cardiac dysfunction, either when considered individually or together, which shed light on the role of vitamin D in general health status. New evidence suggests that SGLT2i could adversely affect the production of vitamin D, thereby increasing the risk of fractures, which are common in patients with T2DM. Therefore, given the biological effects of vitamin D as an anti-inflammatory mediator and a regulator of endothelial function and calcium equilibrium, these new findings should be taken into consideration as well. The aim of this review is to gather the latest advancements regarding the use of antidiabetic and antiplatelet drugs coupled with vitamin D supplementation to control glucose levels, therefore reducing the risk of coronary artery disease (CAD).

Effect of empagliflozin on coronary microvascular function in patients with type 2 diabetes mellitus–A randomized, placebo-controlled cross-over study

Purpose

Results from large scale cardiovascular outcome trials in patients with type 2 diabetes mellitus (DM2) have found that sodium-glucose cotransporter 2 inhibitors (SGLT2i) reduce cardiovascular death and hospitalization for heart failure, but the mechanisms behind the beneficial cardiovascular effects are not fully understood. We tested the hypothesis that the SGLT2i, empagliflozin, improves non-endothelial dependent coronary microvascular function, thereby leading to better cardiac function.

Methods

Patients with DM2 followed at the endocrinology outpatient clinic at Bispebjerg University Hospital were included in a double blinded, placebo-controlled cross-over study. Participants were allocated equally to each treatment sequence using simple randomization and treated with empagliflozin 25 mg and placebo for 12 weeks, interrupted by 2 weeks wash-out period. The primary outcome was coronary microvascular function, assessed as coronary flow velocity reserve (CFVR) and measured with transthoracic doppler echocardiography. Echocardiographic parameters of cardiac function were measured, and blood samples were analyzed for a broad panel of cardiovascular biomarkers.

Results

Thirteen patients were randomized to each sequence and 10 and 9 completed the study according to protocol, respectively, and were included in the analysis of outcome parameters. We found no improvement in CFVR (change in the empagliflozin period was -0.16 (SD 0.58)). There were no effects on cardiac systolic function or indicators of cardiac filling pressure. Well-known effects of empagliflozin were obtained, such as weight loss and reduction in Hba1c level. Creatinine level increased but remained within normal range. We observed a clear trend of reduction in cardiovascular biomarkers after empagliflozin treatment and increased levels after the placebo period. No serious adverse reactions were reported.

Conclusions

Despite effect on weight-loss, Hba1c and biomarkers, treatment with empagliflozin for 12 weeks did not improve CFVR in patients with DM2.

Cystamine reduces vascular stiffness in Western diet-fed female mice

Consumption of diets high in fat, sugar, and salt (Western diet, WD) is associated with accelerated arterial stiffening, a major independent risk factor for cardiovascular disease (CVD). Women with obesity are more prone to develop arterial stiffening leading to more frequent and severe CVD compared with men. As tissue transglutaminase (TG2) has been implicated in vascular stiffening, our goal herein was to determine the efficacy of cystamine, a nonspecific TG2 inhibitor, at reducing vascular stiffness in female mice chronically fed a WD. Three experimental groups of female mice were created. One was fed regular chow diet (CD) for 43 wk starting at 4 wk of age. The second was fed a WD for the same 43 wk, whereas a third cohort was fed WD, but also received cystamine (216 mg/kg/day) in the drinking water during the last 8 wk on the diet (WD + C). All vascular stiffness parameters assessed, including aortic pulse wave velocity and the incremental modulus of elasticity of isolated femoral and mesenteric arteries, were significantly increased in WD- versus CD-fed mice, and reduced in WD + C versus WD-fed mice. These changes coincided with respectively augmented and diminished vascular wall collagen and F-actin content, with no associated effect in blood pressure. In cultured human vascular smooth muscle cells, cystamine reduced TG2 activity, F-actin:G-actin ratio, collagen compaction capacity, and cellular stiffness. We conclude that cystamine treatment represents an effective approach to reduce vascular stiffness in female mice in the setting of WD consumption, likely because of its TG2 inhibitory capacity.NEW & NOTEWORTHY This study evaluates the novel role of transglutaminase 2 (TG2) inhibition to directly treat vascular stiffness. Our data demonstrate that cystamine, a nonspecific TG2 inhibitor, improves vascular stiffness induced by a diet rich in fat, fructose, and salt. This research suggests that TG2 inhibition might bear therapeutic potential to reduce the disproportionate burden of cardiovascular disease in females in conditions of chronic overnutrition.

The Effect of Sodium-Dependent Glucose Cotransporter 2 Inhibitor Tofogliflozin on Neurovascular Coupling in the Retina in Type 2 Diabetic Mice

We investigated the effect of tofogliflozin, a sodium-dependent glucose cotransporter 2 inhibitor (SGLT2i), on retinal blood flow dysregulation, neural retinal dysfunction, and the impaired neurovascular coupling in type 2 diabetic mice. Tofogliflozin was added to mouse chow to deliver 5 mg/kg/day and 6-week-old mice were fed for 8 weeks. The longitudinal changes in the retinal neuronal function and blood flow responses to systemic hyperoxia and flicker stimulation were evaluated every 2 weeks in diabetic db/db mice that received tofogliflozin (n =6) or placebo (n = 6) from 8 to 14 weeks of age. We also evaluated glial activation and vascular endothelial growth factor (VEGF) expression by immunofluorescence. Tofogliflozin treatment caused a sustained decrease in blood glucose in db/db mice from 8 weeks of the treatment. In tofogliflozin-treated db/db mice, both responses improved from 8 to 14 weeks of age, compared with vehicle-treated diabetic mice. Subsequently, the electroretinography implicit time for the oscillatory potential was significantly improved in SGLT2i-treated db/db mice. The systemic tofogliflozin treatment prevented the activation of glial fibrillary acidic protein and VEGF protein expression, as detected by immunofluorescence. Our results suggest that glycemic control with tofogliflozin significantly improved the impaired retinal neurovascular coupling in type 2 diabetic mice with the inhibition of retinal glial activation.

Renal outcomes with sodium-glucose cotransporters 2 inhibitors

Diabetic nephropathy (DN) is one of the most serious complications of diabetes. Therefore, delaying and preventing the progression of DN becomes an important goal in the clinical treatment of type 2 diabetes mellitus. Recent studies confirm that sodium-glucose cotransporters 2 inhibitors (SGLT2is) have been regarded as effective glucose-lowering drugs with renal protective effect. In this review, we summarize in detail the present knowledge of the effects of SGLT2is on renal outcomes by analyzing the experimental data in preclinical study, the effects of SGLT2is on estimated glomerular flitration rates (eGFRs) and urinary albumin-creatinine ratios (UACRs) from clinical trials and observational studies, and renal events (such as renal death or renal failure requiring renal replacement therapy) in some large prospective cardiovaslucar outcomes trials. The underlying mechanisms for renoprotective activity of SGLT2is have been demondtrated in multiple diabetic and nondiabetic animal models including kidney-specific effects and secondary kidney effects related to amelioration in blood glucose and blood pressure. In conclusion, these promising results show that SGLT2is act beneficially in terms of the kidney for diabetic patients.

Effects of SGLT2 Inhibitors on Atherosclerosis: Lessons from Cardiovascular Clinical Outcomes in Type 2 Diabetic Patients and Basic Researches

Atherosclerosis-caused cardiovascular diseases (CVD) are the leading cause of mortality in type 2 diabetes mellitus (T2DM). Sodium-glucose cotransporter 2 (SGLT2) inhibitors are effective oral drugs for the treatment of T2DM patients. Multiple pre-clinical and clinical studies have indicated that SGLT2 inhibitors not only reduce blood glucose but also confer benefits with regard to body weight, insulin resistance, lipid profiles and blood pressure. Recently, some cardiovascular outcome trials have demonstrated the safety and cardiovascular benefits of SGLT2 inhibitors beyond glycemic control. The SGLT2 inhibitors empagliflozin, canagliflozin, dapagliflozin and ertugliflozin reduce the rates of major adverse cardiovascular events and of hospitalization for heart failure in T2DM patients regardless of CVD. The potential mechanisms of SGLT2 inhibitors on cardioprotection may be involved in improving the function of vascular endothelial cells, suppressing oxidative stress, inhibiting inflammation and regulating autophagy, which further protect from the progression of atherosclerosis. Here, we summarized the pre-clinical and clinical evidence of SGLT2 inhibitors on cardioprotection and discussed the potential molecular mechanisms of SGLT2 inhibitors in preventing the pathogenesis of atherosclerosis and CVD.

Predicted Cardiac Functional Responses to Renal Actions of SGLT2i in the DAPACARD Trial Population: A Mathematical Modeling Analysis

Sodium-glucose cotransporter-2 inhibitors (SGLT2is) have been shown to reduce the risk of worsening heart failure (HF) in subjects with HF and a reduced ejection fraction (HFrEF) in multiple clinical trials. The DAPACARD clinical trial was conducted to examine the effects of DAPAgliflozin on CARDiac substrate uptake, myocardial efficiency, and myocardial contractile work in type 2 diabetes mellitus (T2DM) subjects. As a complement to the clinical study, a mechanistic mathematical model of cardiorenal physiology was used to quantify the influence of established natriuretic/diuretic effects of SGLT2i on cardiac function (myocardial efficiency and global longitudinal strain). Virtual participants reflecting the participant-level characteristics in the DAPACARD trial were produced by varying model parameters over physiologically plausible ranges. A second virtual population was generated by inducing a state of HFrEF in the DAPACARD T2DM virtual participants (DAPACARD-HFrEF virtual participants) for comparison. Cardiac responses to placebo and SGLT2i were simulated over 42 days. Cardiac hemodynamic improvements were predicted in DAPACARD-HFrEF virtual participants but not in DAPACARD virtual participants. In particular, the natriuresis/diuresis induced by SGLT2i improved the global longitudinal strain and myocardial efficiency in DAPACARD-HFrEF virtual participants within the first 14 days (change from baseline: global longitudinal strain: -0.95% and myocardial efficiency: 0.34%), whereas the global longitudinal strain and myocardial efficiency in DAPACARD virtual participants were slightly worse (change from baseline: global longitudinal strain: 0.35% and myocardial efficiency: -0.01%). The results of the DAPACARD virtual participants modeling were in line with the clinical data but do not preclude additional effects from other mechanisms of SGLT2i. This article is protected by copyright. All rights reserved.

Hypertension in Diabetes: An Update of Basic Mechanisms and Clinical Disease

Epidemiological studies have documented that insulin resistance and diabetes not only constitute metabolic abnormalities but also predispose to hypertension, vascular stiffness, and associated cardiovascular disease. Meanwhile, excessive arterial stiffness and impaired vasorelaxation, in turn, contribute to worsening insulin resistance and the development of diabetes. Molecular mechanisms promoting hypertension in diabetes include inappropriate activation of the renin-angiotensin-aldosterone system and sympathetic nervous system, mitochondria dysfunction, excessive oxidative stress, and systemic inflammation. This review highlights recent studies which have uncovered new underlying mechanisms for the increased propensity for the development of hypertension in association with diabetes. These include enhanced activation of epithelial sodium channels, alterations in extracellular vesicles and their microRNAs, abnormal gut microbiota, and increased renal sodium-glucose cotransporter activity, which collectively predispose to hypertension in association with diabetes. This review also covers socioeconomic factors and currently recommended blood pressure targets and related treatment strategies in diabetic patients with hypertension.

Cardiovascular Benefits from Gliflozins: Effects on Endothelial Function

Type 2 diabetes mellitus (T2DM) is a known independent risk factor for atherosclerotic cardiovascular disease (CVD) and solid epidemiological evidence points to heart failure (HF) as one of the most common complications of diabetes. For this reason, it is imperative to consider the prevention of CV outcomes as an effective goal for the management of diabetic patients, as important as lowering blood glucose. Endothelial dysfunction (ED) is an early event of atherosclerosis involving adhesion molecules, chemokines, and leucocytes to enhance low-density lipoprotein oxidation, platelet activation, and vascular smooth muscle cell proliferation and migration. This abnormal vascular phenotype represents an important risk factor for the genesis of any complication of diabetes, contributing to the pathogenesis of not only macrovascular disease but also microvascular damage. Gliflozins are a novel class of anti-hyperglycemic agents used for the treatment of Type 2 diabetes mellitus (T2DM) that selectively inhibit the sodium glucose transporter 2 (SGLT2) in the kidneys and have provoked large interest in scientific community due to their cardiovascular beneficial effects, whose underlying pathophysiology is still not fully understood. This review aimed to analyze the cardiovascular protective mechanisms of SGLT2 inhibition in patients T2DM and their impact on endothelial function.