Minireview: are SGLT2 inhibitors heart savers in diabetes?

Biochemical and histopathological evidence for beneficial effects of Empagliflozin pretreatment on acetic acid-induced colitis in rats

BACKGROUND

Ulcerative Colitis (UC) is a disorder which oxidative stress plays a critical role in its pathogenesis. Empagliflozin (EMPA) is a sodium-glucose cotransporter-2 (SGLT2) inhibitor that has been shown to have anti-inflammatory and antioxidative effects. The aim of this study was to investigate the protective effects of EMPA on acetic acid (AA) induced colitis in rats.

METHODS

A total of twenty-four rats were divided into four groups (six animals in each group) as follows: (1) Control group; (2) acetic acid (AA)-induced colitis group (AA); (3) EMPA treatment group (AA + EMPA); (4) Dexamethasone (Dexa) treatment group (AA + Dexa). Animals in pre-treatment groups received EMPA (10 mg/kg, i.p.) or dexamethasone (4 mg/kg, i.p. as reference drug) for four consecutive days before induction of colitis by intra-rectal acetic acid (4% v/v) administration. Twenty-four hours after AA administration, rats were sacrificed and the colon tissues were removed for histopathological and biochemical evaluations.

RESULTS

Pretreatment with EMPA significantly decreased colon weight/length ratio (81.00 ± 5.28 mg/cm vs. 108.80 ± 5.51 mg/cm) as well as, macroscopic (2.50 ± 0.57 vs. 3.75 ± 0.25) and histological scores (3.3 ± 0.14 vs. 1.98 ± 0.14) compared to the AA-induced colitis group (p < 0.01). Pretreatment with EMPA significantly reduced malondialdehyde (MDA) (324.0 ± 15.93 vs. 476.7 ± 32.26 nmol/mg p < 0.001) and increased glutathione level (117.5 ± 4.48 vs. 94.38 ± 3.950 µmol/mg, p < 0.01) in comparison to the AA-induced colitis group. Furthermore, a significant increase in catalase (44.60 ± 4.02 vs.14.59 ± 2.03 U/mg, P < 0.01), superoxide dismutase (283.9 ± 18.11 vs. 156.4 ± 7.92 U/mg, p < 0.001), and glutathione peroxidase (10.38 ± 1.45 vs. 2.508 ± 0.37, p < 0.01) activities were observed by EMPA pretreatment when compared to the AA-induced colitis group. These results were in line with those of the reference drug.

CONCLUSIONS

It is concluded that EMPA could effectively reduce the severity of tissue injury in experimental colitis. This protective effect may be related to the antioxidative effects of EMPA drug.

Comparison of SGLT2 inhibitors with DPP-4 inhibitors combined with metformin in patients with acute myocardial infarction and diabetes mellitus

BACKGROUND

Although sodium-glucose cotransporter 2 inhibitors (SGLT2i) have demonstrated cardiovascular benefits in patients with type 2 diabetes mellitus, real-world evidence regarding their benefits to diabetic patients with acute myocardial infarction (AMI) is insufficient. This study evaluated cardiovascular outcomes by comparing SGLT2i with dipeptidyl peptidase-4 inhibitors (DPP-4i) in combination with metformin in diabetic patients with AMI.

METHODS

This study involved 779 diabetic participants with AMI from a Korean nationwide multicenter observational cohort, who were divided into two groups: (1) metformin plus SGLT2i group (SGLT2i group, n = 186) and (2) metformin plus DPP-4i (DPP-4i group, n = 593). The primary endpoint was one year of major adverse composite events (MACEs), a composite outcome of all-cause mortality, non-fatal myocardial infarction, any revascularization, cerebrovascular accident, and stent thrombosis. To balance the baseline differences, inverse probability of treatment weighting (IPTW) was performed.

RESULTS

After IPTW, the rate of MACEs in the SGLT2i group was not significantly lower than that in the DPP-4i group (hazard ratio [HR], 0.99; 95% confidence interval [Cl], 0.46 to 2.14, p = 0.983). In the unadjusted and adjusted analyses, all items for clinical outcomes were comparable between the two groups. In our exploratory analysis, the left ventricular ejection fraction showed a significant improvement in the SGLT2i group than in the DPP-4i group before achieving statistical balancing (6.10 ± 8.30 versus 2.95 ± 10.34, p = 0.007) and after IPTW adjustment (6.91 ± 8.91 versus 3.13 ± 10.41, p = 0.027).

CONCLUSIONS

Our findings demonstrated that SGLT2i did not influence the rate of MACEs compared with DPP-4i in combination with metformin in diabetic patients with AMI but did improve left ventricular ejection fraction.

TRIAL REGISTRATION

Not applicable (retrospectively registered).

Impact of SGLT2 inhibitors on the mechanisms of myocardial dysfunction in type 2 diabetes: A prospective non-randomized observational study in patients with type 2 diabetes mellitus without overt heart disease

AIMS

This prospective observational study evaluated the possible mechanisms of action of SGLT2 inhibitors (SGLT2i) in patients with type 2 diabetes mellitus (T2DM) without overt heart disease.

METHODS

The study was designed to verify whether SGLT2i impact biomarkers of: myocardial stress-NT-proBNP, inflammation-high sensitivity C-reactive protein, oxidative stress -myeloperoxidase, functional and structural echocardiographic parameters, in patients with T2DM on metformin (heart failure stages A and B) who needed treatment intensification with a second antidiabetic agent. The patients were divided in two groups - the ones planned to receive SGLT2i or DPP-4 inhibitor (except saxagliptin). At baseline, and after six months of therapy, 64 patients underwent blood analysis, physical and echocardiography examination.

RESULTS

There were no significant differences between the two groups in terms of biomarkers of myocyte and oxidative stress, inflammation and blood pressure. Body mass index, triglycerides, aspartate aminotransferase, uric acid, E/E', deceleration time and systolic pressure in the pulmonary artery significantly decreased, while stroke volume, indexed stroke volume, high-density lipoprotein, hematocrit and hemoglobin significantly increased in the group on SGLT2i.

CONCLUSIONS

According to the results, SGLT2i mechanisms of action comprise rapid changes in body composition and metabolic parameters, reduced cardiac load and improvement in diastolic and systolic parameters.

Mechanisms of current therapeutic strategies for heart failure: more questions than answers?

Heart failure (HF) is a complex, multifactorial and heterogeneous syndrome with substantial mortality and morbidity. Over the last few decades, numerous attempts have been made to develop targeted therapies that may attenuate the known pathophysiological pathways responsible for causing the progression of HF. However, therapies developed with this objective have sometimes failed to show benefit. The pathophysiological construct of HF with numerous aetiologies suggests that interventions with broad mechanisms of action which simultaneously target more than one pathway maybe more effective in improving the outcomes of patients with HF. Indeed, current therapeutics with clinical benefits in HF have targeted a wider range of intermediate phenotypes. Despite extensive scientific breakthroughs in HF research recently, questions persist regarding the ideal therapeutic targets which may help achieve maximum benefit. In this review, we evaluate the mechanism of action of current therapeutic strategies, the pathophysiological pathways they target and highlight remaining knowledge gaps regarding the mode of action of these interventions.

Insights into efficacy and safety of dapagliflozin treatment for the management in older adults with type 2 diabetes: a systematic review and meta-analysis

BACKGROUND

This study aimed to evaluate the efficacy and safety of dapagliflozin as a monotherapy glucose-lowering drug treatment for older adults with diabetes.

RESEARCH DESIGN & METHODS

Randomized controlled trial reports were retrieved from PubMed, Embase Cochrane Library, and Web of Science from database inception to 8 May 2021. Publication bias and heterogeneity were assessed using the Cochrane risk-of-bias tool and the Cochrane Q statistic, respectively.

RESULTS

Compared with placebo, dapagliflozin as a monotherapy glucose-lowering drug did improve the control of glycosylated hemoglobin and fasting plasma glucose levels in older adults. Our analysis also confirmed that the body weight of older adults was well controlled under treatment of dapagliflozin as a monotherapy glucose-lowering drug. Patients in older adults with diabetes took a higher risk of genital infection and renal impairment or failure after treatment of dapagliflozin. In addition, treatment with dapagliflozin reduced the risk of hypoglycemia, and did not reveal increased risk of urinary tract infection and developing fractures compared to placebo in older adults.

CONCLUSIONS

Dapagliflozin as a monotherapy glucose-lowering drug appeared to be an effective treatment for older adults with diabetes, although it might increase risk of genital infection and renal impairment or failure.

Cell-Target-Specific Anti-Inflammatory Effect of Empagliflozin: In Vitro Evidence in Human Cardiomyocytes

The antidiabetic sodium–glucose cotransporter type 2 inhibitor (SGLT2i) empagliflozin efficiently reduces heart failure (HF) hospitalization and cardiovascular death in type 2 diabetes (T2D). Empagliflozin-cardioprotection likely includes anti-inflammatory effects, regardless glucose lowering, but the underlying mechanisms remain unclear. Inflammation is a primary event in diabetic cardiomyopathy (DCM) and HF development. The interferon (IFN)γ-induced 10-kDa protein (IP-10/CXCL10), a T helper 1 (Th1)-type chemokine, promotes cardiac inflammation, fibrosis, and diseases, including DCM, ideally representing a therapeutic target. This preliminary study aims to explore whether empagliflozin directly affects Th1-challenged human cardiomyocytes, in terms of CXCL10 targeting. To this purpose, empagliflozin dose–response curves were performed in cultured human cardiomyocytes maintained within a Th1-dominant inflammatory microenvironment (IFNγ/TNFα), and CXCL10 release with the intracellular IFNγ-dependent signaling pathway (Stat-1) was investigated. To verify possible drug–cell-target specificity, the same assays were run in human skeletal muscle cells. Empagliflozin dose dependently inhibited CXCL10 secretion (IC50 = 76,14 × 10-9 M) in association with Stat-1 pathway impairment only in Th1-induced human cardiomyocytes, suggesting drug-selective cell-type-targeting. As CXCL10 plays multifaceted functions in cardiac remodeling toward HF and currently there is no effective method to prevent it, these preliminary data might be hypothesis generating to open new scenarios in the translational approach to SGLT2i-dependent cardioprotection.

Infarct size, inflammatory burden, and admission hyperglycemia in diabetic patients with acute myocardial infarction treated with SGLT2-inhibitors: a multicenter international registry

BACKGROUND

The inflammatory response occurring in acute myocardial infarction (AMI) has been proposed as a potential pharmacological target. Sodium-glucose co-transporter 2 inhibitors (SGLT2-I) currently receive intense clinical interest in patients with and without diabetes mellitus (DM) for their pleiotropic beneficial effects. We tested the hypothesis that SGLT2-I have anti-inflammatory effects along with glucose-lowering properties. Therefore, we investigated the link between stress hyperglycemia, inflammatory burden, and infarct size in a cohort of type 2 diabetic patients presenting with AMI treated with SGLT2-I versus other oral anti-diabetic (OAD) agents.

METHODS

In this multicenter international observational registry, consecutive diabetic AMI patients undergoing percutaneous coronary intervention (PCI) between 2018 and 2021 were enrolled. Based on the presence of anti-diabetic therapy at the admission, patients were divided into those receiving SGLT2-I (SGLT-I users) versus other OAD agents (non-SGLT2-I users). The following inflammatory markers were evaluated at different time points: white-blood-cell count, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), neutrophil-to-platelet ratio (NPR), and C-reactive protein. Infarct size was assessed by echocardiography and by peak troponin levels.

RESULTS

The study population consisted of 583 AMI patients (with or without ST-segment elevation): 98 SGLT2-I users and 485 non-SGLT-I users. Hyperglycemia at admission was less prevalent in the SGLT2-I group. Smaller infarct size was observed in patients treated with SGLT2-I compared to non-SGLT2-I group. On admission and at 24 h, inflammatory indices were significantly higher in non-SGLT2-I users compared to SGLT2-I patients, with a significant increase in neutrophil levels at 24 h. At multivariable analysis, the use of SGLT2-I was a significant predictor of reduced inflammatory response (OR 0.457, 95% CI 0.275-0.758, p = 0.002), independently of age, admission creatinine values, and admission glycemia. Conversely, peak troponin values and NSTEMI occurrence were independent predictors of a higher inflammatory status.

CONCLUSIONS

Type 2 diabetic AMI patients receiving SGLT2-I exhibited significantly reduced inflammatory response and smaller infarct size compared to those receiving other OAD agents, independently of glucose-metabolic control. Our findings are hypothesis generating and provide new insights on the cardioprotective effects of SGLT2-I in the setting of coronary artery disease.

TRIAL REGISTRATION

Data are part of the ongoing observational registry: SGLT2-I AMI PROTECT.

CLINICALTRIALS

gov Identifier: NCT05261867.

An Up-to-Date Article Regarding Particularities of Drug Treatment in Patients with Chronic Heart Failure

Since the prevalence of heart failure (HF) increases with age, HF is now one of the most common reasons for the hospitalization of elderly people. Although the treatment strategies and overall outcomes of HF patients have improved over time, hospitalization and mortality rates remain elevated, especially in developed countries where populations are aging. Therefore, this paper is intended to be a valuable multidisciplinary source of information for both doctors (cardiologists and general physicians) and pharmacists in order to decrease the morbidity and mortality of heart failure patients. We address several aspects regarding pharmacological treatment (including new approaches in HF treatment strategies [sacubitril/valsartan combination and sodium glucose co-transporter-2 inhibitors]), as well as the particularities of patients (age-induced changes and sex differences) and treatment (pharmacokinetic and pharmacodynamic changes in drugs; cardiorenal syndrome). The article also highlights several drugs and food supplements that may worsen the prognosis of HF patients and discusses some potential drug-drug interactions, their consequences and recommendations for health care providers, as well as the risks of adverse drug reactions and treatment discontinuation, as an interdisciplinary approach to treatment is essential for HF patients.

SGLT2 Inhibitors and Ketone Metabolism in Heart Failure

Sodium-glucose cotransporter-2 (SGLT2) inhibitors have emerged as powerful drugs that can be used to treat heart failure (HF) patients, both with preserved and reduced ejection fraction and in the presence or absence of type 2 diabetes. While the mechanisms underlying the salutary effects of SGLT2 inhibitors have not been fully elucidated, there is clear evidence for a beneficial metabolic effect of these drugs. In this review, we discuss the effects of SGLT2 inhibitors on cardiac energy provision secondary to ketone bodies, pathological ventricular remodeling, and inflammation in patients with HF. While the specific contribution of ketone bodies to the pleiotropic cardiovascular benefits of SGLT2 inhibitors requires further clarification, ketone bodies themselves may also be used as a therapy for HF.

Sodium-glucose cotransporter 2 inhibitors’ mechanisms of action in heart failure

Three major cardiovascular outcome trials (CVOTs) with a new class of antidiabetic drugs - sodium-glucose cotransporter 2 (SGLT2) inhibitors (EMPA-REG OUTCOME trial with empagliflozin, CANVAS Program with canagliflozin, DECLARE-TIMI 58 with dapagliflozin) unexpectedly showed that cardiovascular outcomes could be improved possibly due to a reduction in heart failure risk, which seems to be the most sensitive outcome of SGLT2 inhibition. No other CVOT to date has shown any significant benefit on heart failure events. Even more impressive findings came recently from the DAPA-HF trial in patients with confirmed and well-treated heart failure: Dapagliflozin was shown to reduce heart failure risk for patients with heart failure with reduced ejection fraction regardless of diabetes status. Nevertheless, despite their possible wide clinical implications, there is much doubt about the mechanisms of action and a lot of questions to unravel, especially now when their benefits translated to non-diabetic patients, rising doubts about the validity of some current mechanistic assumptions.The time frame of their cardiovascular benefits excludes glucose-lowering and antiatherosclerotic-mediated effects and multiple other mechanisms, direct cardiac as well as systemic, are suggested to explain their early cardiorenal benefits. These are: Anti-inflammatory, antifibrotic, antioxidative, antiapoptotic properties, then renoprotective and hemodynamic effects, attenuation of glucotoxicity, reduction of uric acid levels and epicardial adipose tissue, modification of neurohumoral system and cardiac fuel energetics, sodium-hydrogen exchange inhibition. The most logic explanation seems that SGLT2 inhibitors timely target various mechanisms underpinning heart failure pathogenesis. All the proposed mechanisms of their action could interfere with evolution of heart failure and are discussed separately within the main text.

Mechanisms of Cardiovascular Benefits of Sodium Glucose Co-Transporter 2 (SGLT2) Inhibitors: A State-of-the-Art Review

Recent clinical trials have shown that sodium glucose co-transport 2 (SGLT2) inhibitors have dramatic beneficial cardiovascular outcomes. These include a reduced incidence of cardiovascular death and heart failure hospitalization in people with and without diabetes, and those with and without prevalent heart failure. The actual mechanism(s) responsible for these beneficial effects are not completely clear. Several potential theses have been proposed to explain the cardioprotective effects of SGLT2 inhibition, which include diuresis/natriuresis, blood pressure reduction, erythropoiesis, improved cardiac energy metabolism, inflammation reduction, inhibition of the sympathetic nervous system, prevention of adverse cardiac remodeling, prevention of ischemia/reperfusion injury, inhibition of the Na+/H+-exchanger, inhibition of SGLT1, reduction in hyperuricemia, increasing autophagy and lysosomal degradation, decreasing epicardial fat mass, increasing erythropoietin levels, increasing circulating pro-vascular progenitor cells, decreasing oxidative stress, and improving vascular function. The strengths and weaknesses of these proposed mechanisms are reviewed in an effort to try to synthesize and prioritize the mechanisms as they relate to clinical event reduction.

Prevention of cardiac allograft vasculopathy - A new possible indication for SGLT-2 inhibitors?

One of the main risk factors influencing patient survival after heart transplantation is cardiac allograft vasculopathy, the leading cause of death after the first year of transplantation. It is an entity of multifactorial origin including both humoral and cellular alloimmune responses as well as immunologic-independent factors such as graft injury, ischaemia-reperfusion injury, oxidative stress, cytomegalovirus infection, hyperlipidaemia, diabetes mellitus and hypertension. A fundamental characteristic of cardiac allograft vasculopathy is vascular remodelling, initially driven by the injury and apoptosis of endothelial cells, then by the migration of smooth muscle cells leading to intimal thickening and ultimately allograft vessel occlusion. Since cardiac allograft vasculopathy occurs within the first year of transplantation, prevention strategies should be implemented early. The disease could be partially prevented with overall cardiovascular risk reduction, mainly by controlling diabetes, hyperlipidemia and hypertension that can be related to the recipient but also induced or augmented by immunosuppressive drugs used. Current therapeutic options are only partially effective in postponing the development of vascular lesions. Diabetes is an important issue in the management of patients following cardiac transplantation. Although it is highly prevalent among heart transplant recipients (23% at 1 year increasing to 37% at 5 years after the procedure), no specific therapeutic protocols have been recommended yet. Sodium-glucose cotransporter-2 (SGLT-2) inhibitors are a novel class of antidiabetic drugs that produce glycosuric and natriuretic effects by inhibiting glucose and sodium reabsorption from the renal proximal tubules and have already shown benefits in cardiovascular outcome trials. Our hypothesis is that SGLT-2 inhibitors could prevent or delay the development of cardiac allograft vasculopathy targeting various mechanisms underpinning its pathogenesis due to their antidiabetic, antihypertensive, anti-inflammatory, antifibrotic, antioxidative and antiapoptotic effects, as well as through amelioration of endothelial dysfunction, ischaemia-reperfusion injury and modification of neurohumoral system. All the segments of the proposed theory that could interfere with evolution of vasculopathy are discussed separately within the main text. The implications for the science if the hypothesis were to be confirmed are as follows: prolongation of lifespan in heart transplant patients with diabetes, reduction of polypragmasia in posttransplant patients while targeting several mechanisms with one drug, and the possibility of spreading the indications even to patients without diabetes.