SGLT-2 Inhibitors and Cardiovascular Protection: Lessons and Gaps in Understanding the Current Outcome Trials and Possible Benefits of Combining SGLT-2 Inhibitors With GLP-1 Agonists

SGLT2 Inhibitor Canagliflozin Alleviates High Glucose-Induced Inflammatory Toxicity in BV-2 Microglia

Patients with diabetes mellitus can experience hyperglycemia, which affects brain function and produces cognitive impairment or neurodegeneration. Neuroinflammation is an important cause of cognitive dysfunction. Sodium-glucose cotransporter 2 (SGLT2) inhibitors are antihyperglycemic agents that reportedly possess anti-inflammatory properties and may produce beneficial cognitive effects. We hypothesized that SGLT2 inhibitors alleviate hyperglycemia-related inflammation in brain immune cells. Cultured BV-2 microglia were exposed to high glucose (HG) in the absence or presence of SGLT2 inhibitors including canagliflozin (Cana), dapagliflozin (Dapa), empagliflozin (Empa), and ertugliflozin (Ertu). Afterward, we evaluated the cytotoxic and inflammatory responses by specific biochemical assays. Treatments with non-toxic Cana or Dapa, but not Empa or Ertu, inhibited proliferation without cell death. Only Cana rescued BV-2 microglia from HG-induced cytotoxicity, including apoptosis or autophagic degradation. None of SGLT2 inhibitors affected the HG-stimulated induction of stress proteins HO-1 and HSP70. Also, compared to the other three SGLT2 inhibitors, Cana was better at inhibiting HG-induced oxidative/inflammatory stress, as evidenced by its ability to repress proinflammatory factors (e.g., oxygen free radicals, iNOS, NLRP3, IL-1β, and TNF-α) other than COX-2. Cana's action to alleviate HG insults was mediated not by altering SGLT2 protein expression, but by reducing HG-stimulated signaling activities of NFκB, JNK, p38, and PI3K/Akt pathways. Particularly, Cana imitated the effects of NFκB inhibitor on HG-induced iNOS and COX-2. Of the four SGLT2 inhibitors, Cana provided BV-2 microglia with the best protection against HG-induced inflammatory toxicity. Thus, Cana may help to reduce innate neuroimmune damage caused by hyperglycemia.

The Ketogenic Effect of SGLT-2 Inhibitors-Beneficial or Harmful?

Sodium-glucose cotransporter-2 (SGLT-2) inhibitors, also called gliflozins or flozins, are a class of drugs that have been increasingly used in the management of type 2 diabetes mellitus (T2DM) due to their glucose-lowering, cardiovascular (CV), and renal positive effects. However, recent studies suggest that SGLT-2 inhibitors might also have a ketogenic effect, increasing ketone body production. While this can be beneficial for some patients, it may also result in several potential unfavorable effects, such as decreased bone mineral density, infections, and ketoacidosis, among others. Due to the intricate and multifaceted impact caused by SGLT-2 inhibitors, this initially anti-diabetic class of medications has been effectively used to treat both patients with chronic kidney disease (CKD) and those with heart failure (HF). Additionally, their therapeutic potential appears to extend beyond the currently investigated conditions. The objective of this review article is to present a thorough summary of the latest research on the mechanism of action of SGLT-2 inhibitors, their ketogenesis, and their potential synergy with the ketogenic diet for managing diabetes. The article particularly discusses the benefits and risks of combining SGLT-2 inhibitors with the ketogenic diet and their clinical applications and compares them with other anti-diabetic agents in terms of ketogenic effects. It also explores future directions regarding the ketogenic effects of SGLT-2 inhibitors.

Molecular and neural roles of sodium-glucose cotransporter 2 inhibitors in alleviating neurocognitive impairment in diabetic mice

Diabetes causes a variety of molecular changes in the brain, making it a real risk factor for the development of cognitive dysfunction. Complex pathogenesis and clinical heterogeneity of cognitive impairment makes the efficacy of current drugs limited. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) gained our attention as drugs with potential beneficial effects on the CNS. In the present study, these drugs ameliorated the cognitive impairment associated with diabetes. Moreover, we verified whether SGLT2i can mediate the degradation of amyloid precursor protein (APP) and modulation of gene expression (Bdnf, Snca, App) involved in the control of neuronal proliferation and memory. The results of our research proved the participation of SGLT2i in the multifactorial process of neuroprotection. SGLT2i attenuate the neurocognitive impairment through the restoration of neurotrophin levels, modulation of neuroinflammatory signaling, and gene expression of Snca, Bdnf, and App in the brain of diabetic mice. The targeting of the above-mentioned genes is currently seen as one of the most promising and developed therapeutic strategies for diseases associated with cognitive dysfunction. The results of this work could form the basis of a future administration of SGLT2i in diabetics with neurocognitive impairment.

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

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

Sodium-glucose co-transporter-2 inhibitors in patients with type 2 diabetes mellitus without established cardiovascular disease: Do they have a role in primary prevention?

Most guidelines and cardiovascular outcome trials (CVOTs) focus on secondary prevention of cardiovascular disease (CVD) in type 2 diabetes mellitus (T2DM). Patients with T2DM without established CVD (eCVD) also form a critical cohort, for whom primary prevention with timely pharmacological and non-pharmacological interventions can effectively prevent or delay the onset of CVD. Sodium-glucose co-transporter 2 inhibitors (SGLT2i) have demonstrated a promising role for primary prevention of CVD in CVOTs and real-world studies. The 2019 American College of Cardiology/American Heart Association guidelines on primary prevention of CVD recommend SGLT2i as one of the add-on treatment options to metformin for adults with T2DM and glycated hemoglobin >7% who have cardiovascular (CV) risk factors. The outcomes with maximal response to SGLT2i use in primary prevention are hospitalization for heart failure and chronic kidney disease. The cardiorenal benefits with SGLT2i are attributed to pleiotropic effects on CV risk factors, and interference with glucose and sodium handling in kidneys, independent of their glycemic benefits. Results therefore support a role for SGLT2i not only in patients with T2DM and eCVD but also in patients with T2DM without eCVD. This review examines the evidence for potential role of SGLT2i for primary prevention of CVD in T2DM.

Perspective of SGLT2 Inhibition in Treatment of Conditions Connected to Neuronal Loss: Focus on Alzheimer's Disease and Ischemia-Related Brain Injury

Sodium-glucose co-transporter 2 inhibitors (SGLT2i) are oral anti-hyperglycemic agents approved for the treatment of type 2 diabetes mellitus. Some reports suggest their presence in the central nervous system and possible neuroprotective properties. SGLT2 inhibition by empagliflozin has shown to reduce amyloid burden in cortical regions of APP/PS1xd/db mice. The same effect was noticed regarding tau pathology and brain atrophy volume. Empagliflozin presented beneficial effect on cognitive function, which may be connected to an increase in cerebral brain-derived neurotrophic factor. Canagliflozin and dapagliflozin may possess acetylcholinesterase inhibiting activity, resembling in this matter Alzheimer’s disease-registered therapies. SGLT2 inhibitors may prove to impact risk factors of atherosclerosis and pathways participating both in acute and late stage of stroke. Their mechanism of action can be related to induction in hepatocyte nuclear factor-1α, vascular endothelial growth factor-A, and proinflammatory factors limitation. Empagliflozin may have a positive effect on preservation of neurovascular unit in diabetic mice, preventing its aberrant remodeling. Canagliflozin seems to present some cytostatic properties by limiting both human and mice endothelial cells proliferation. The paper presents potential mechanisms of SGLT-2 inhibitors in conditions connected with neuronal damage, with special emphasis on Alzheimer’s disease and cerebral ischemia.

Cardiovascular outcome trials of glucose-lowering therapies

INTRODUCTION

Early initiated and long-term sustained intensive glucose control is associated with a significantly decreased risk of cardiovascular events and all-cause mortality, over and above the well-established decline in the risk of microvascular disease. Based on the recent cardiovascular outcome trial (CVOT) data, this review focuses on the various benefits of the newer medications with their positioning in the treatment algorithm and explores the place of the older medications in the management of type 2 diabetes mellitus (T2DM).

AREAS COVERED

We searched the literature for glucose-lowering therapies for patients with T2DM. We included CVOTs conducted for newer sulphonylureas, thiazolidinediones, insulin degludec, DPP-4 inhibitors, SGLT2 inhibitors, and GLP-1 receptor agonists.

EXPERT OPINION

Selection of glucose-lowering therapy in the management of T2DM should be individualized and based on patient characteristics, associated comorbidities, patient preference, affordability and adherence to treatment. In view of the benefits seen in the CVOTs with SGLT2 inhibitors and GLP-1 receptor agonists, these newer classes should be the preferred choice in patients with/without established atherosclerotic cardiovascular disease and chronic kidney disease.

Differential indication for SGLT-2 inhibitors versus GLP-1 receptor agonists in patients with established atherosclerotic heart disease or at risk for congestive heart failure

SGLT-2 inhibitors and most GLP-1 receptor agonists demonstrated cardiovascular superiority and reduction of cardiovascular and overall mortality. These results stand as a turning point in the management of diabetes, shifting the focus from controlling glucose levels to mastering the extra-glycemic effects of these new drugs. This narrative review will discuss recent CVOT with focus on SGLT-2 inhibitors and GLP-1 receptor agonists to distinguish relevant patients' characteristics as potential predictors for therapeutic efficacy. It will also examine their efficacy and safety, the differences in their cardiovascular and renal benefits, aiming to convey clinical suggestions for everyday practice.

Effect of Sodium-Glucose Cotransporter-2 Inhibitors versus Dipeptidyl Peptidase 4 Inhibitors on Cardiovascular Function in Patients with Type 2 Diabetes Mellitus and Coronary Artery Disease

Background

Randomized controlled trials demonstrated lowering risks of cardiovascular events with sodium-glucose cotransporter-2 (SGLT2) inhibitors in patients with type 2 diabetes mellitus (T2DM) and high cardiovascular risk. We analyzed the effects of cardiovascular function on SGLT2 inhibitors compared with dipeptidyl peptidase-4 (DPP4) inhibitors in T2DM with atherosclerotic cardiovascular disease (ASCVD) or heart failure (HF).

Methods

This is a retrospective, observational, single center study. Data from 89 patients with ASCVD or HF from January 2015 to February 2018 were analyzed regarding the effect of SGLT2 inhibitors and DPP4 inhibitors. Cardiovascular function was assessed by 2-D echocardiography and N-terminal prohormone of brain natriuretic peptide (NT-pro BNP).

Results

A total of 89 patients with T2DM were considered in two groups of SGLT2 inhibitors (n=41) and DPP4 inhibitors (n=48). The mean follow-up period was 2 years, with a total of 89 patient-years. Despite no significant change in systolic function, SGLT2 inhibitors improved cardiovascular function, as demonstrated by a reduced left ventricular ejection fraction less than 40%, ratio of mitral peak velocity of early filling velocity to early diastolic mitral annular velocity, ratio of early to late ventricular filling velocities, and NT-pro BNP compared with the DPP4 inhibitor group.

Conclusion

SGLT2 inhibitors improve cardiovascular function in T2DM with coronary artery disease compared to DPP4 inhibitors.

Diabesity and antidiabetic drugs

The prevalence of "diabesity" - diabetes related to obesity - has increased tremendously over the past few decades because of the global obesity epidemic. Although bariatric surgery is the best treatment option for patients with diabesity, a majority of patients are managed only with antidiabetic drugs for various reasons. Diabetes control with antidiabetic agents may affect diabesity outcomes positively or negatively because of their effects on body weight and other metabolic parameters. For this reason, rational use of anti-diabetic medications is imperative to optimise long-term management of diabesity. Understanding the molecular mechanisms of antidiabetic drugs and/or drug combinations on diabesity outcomes are therefore important not only for the basic scientists but also for clinicians. This review explores the molecular signalling cascades of antidiabetic medications in the management of diabesity.