Targeting Features of the Metabolic Syndrome Through Sympatholytic Effects of SGLT2 Inhibition

Anaemia predicts iron homoeostasis dysregulation and modulates the response to empagliflozin in heart failure with reduced ejection fraction: the EMPATROPISM-FE trial

BACKGROUND AND AIMS

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) impact iron metabolism in patients with heart failure but mechanisms are incompletely understood. This post hoc analysis explored interrelations between iron homeostasis, cardiac structure/function, exercise capacity, haematopoiesis, and sympathetic activity at baseline, and the effects of 6-month treatment with empagliflozin vs. placebo by anaemia status in EMPATROPISM-FE study participants.

METHODS

Myocardial iron content (MIC, estimated by cardiac magnetic resonance T2* imaging), left ventricular (LV) volumes and LV ejection fraction (LVEF), exercise capacity, laboratory iron markers (LIM), haemoglobin/haematocrit, erythropoietin, and plasma norepinephrine were determined at baseline and 6 months.

RESULTS

At baseline, 24/80 participants (30%) had anaemia (haemoglobin < 13/<12 mg/dL in men/women). Patients with vs. without anaemia had higher T2* (indicating lower MIC, P < .001), lower peak oxygen consumption (VO2max, P = .024) and hepcidin (P = .017), and higher erythropoietin (P = .040) and norepinephrine (P = .016). Across subgroups, lower MIC correlated with higher LV volumes (P < .01) and norepinephrine (P < .001), and lower LVEF (P < .01), VO2max (P < .001) and haemoglobin/haematocrit (P < .001). Associations with LIM were poor (all P > .10). Empagliflozin increased MIC (P < .012), improved exercise capacity, and activated haematopoiesis. Changes in LIM and norepinephrine suggested progressive systemic iron depletion and sympatholysis. LV reverse remodelling was greater in individuals with anaemia.

CONCLUSIONS

Dysregulated cellular iron uptake/availability may be a shared mechanism in myocardial structural/functional impairment, reduced exercise capacity, and restricted haematopoiesis in heart failure, which are worse in patients with anaemia, and improve with empagliflozin. Empagliflozin increases MIC and decreases norepinephrine. Given this inverse association, sympatholysis may help explain the diverse cardiac and systemic benefits from SGLT2i therapy.

CLINICAL TRIAL REGISTRATION

NCT03485222 (www.clinicaltrials.gov).

[Association between sociodemographic variables, healthy habits and stress with metabolic syndrome. A descriptive, cross-sectional study]

INTRODUCTION

Metabolic syndrome (MS) is a pathological condition that encompasses various cardiometabolic risk factors, such as obesity, dyslipidemia, hyperglycemia, and elevated blood pressure levels. It is considered a multifactorial pathological condition. The aim of this study is to assess how variables such as age, sex, socioeconomic status, tobacco and alcohol consumption, physical activity, adherence to the Mediterranean diet, and stress are associated with the prevalence of MS, determined using two different criteria.

MATERIALS AND METHODS

This is a descriptive, cross-sectional study conducted on 24,224 Spanish workers, evaluating the association between sociodemographic variables, health habits, and stress with MS, determined using two criteria: the National Cholesterol Education Program, Adult Treatment Panel III (NCEP ATP-III), and the International Diabetes Federation (IDF).

RESULTS

All the variables analyzed showed an association with the presence of MS when applying both criteria. Among them, the variables with the strongest association were age: odds ratio 5.55 (95% CI: 4.80-6.30) for MS using the NCEP ATP-III criteria and 6.71 (95% CI: 5.30-8.13) for IDF criteria; and type of job: odds ratio 3.42 (95% CI: 2.95-3.90) for NCEP ATP-III and 3.57 (95% CI: 3.12-4.03) for IDF.

CONCLUSIONS

The profile of an individual at higher risk of developing MS under both criteria would be an older male, manual laborer, smoker, habitual alcohol consumer, sedentary, with low adherence to the Mediterranean diet, and experiencing high levels of stress.

Uric acid in diabetic microvascular complications: Mechanisms and therapy

Uric acid (UA) is mainly synthesized in the liver, intestine, and vascular endothelium and excreted by the kidney (70 %) and intestine (30 %). Hyperuricemia (HUA) occurs when UA production exceeds excretion. Many studies have found that elevated UA is associated with diabetic microvascular complications (DMC), including diabetic retinopathy (DR), diabetic nephropathy (DN), and diabetic peripheral neuropathy (DPN). In addition, too high or too low UA levels will promote the occurrence and development of chronic diseases, but the relationship between UA and diabetic microvascular complications (DMC) is not clear. Therefore, the rational treatment of UA in patients with diabetes is essential. In this review, we summarize and discuss the mechanism and treatment of UA and DMC and may provide potential advice for rational drug selection.

Central SGLT2 mediate sympathoexcitation in hypertensive heart failure via attenuating subfornical organ endothelial cGAS ubiquitination to amplify neuroinflammation: Molecular mechanism behind sympatholytic effect of Empagliflozin

BACKGROUND

Sodium/glucose co-transporter 2 (SGLT2) inhibitors have transformed heart failure (HF) treatment, offering sympatholytic effects whose mechanisms are not fully understood. Our previous studies identified Cyclic GMP-AMP synthase (cGAS)-derived neuroinflammation in the Subfornical organ (SFO) as a promoter of sympathoexcitation, worsening myocardial remodeling in HF. This research explored the role of central SGLT2 in inducing endothelial cGAS-driven neuroinflammation in the SFO during HF and assessed the impact of SGLT2 inhibitors on this process.

METHODS

Hypertensive HF was induced in mice via Angiotensin II infusion for four weeks. SGLT2 expression and localization in the SFO were determined through immunoblotting and double-immunofluorescence staining. AAV9-TIE-shRNA (SGLT2) facilitated targeted SGLT2 knockdown in SFO endothelial cells (ECs), with subsequent analyses via immunoblotting, staining, and co-immunoprecipitation to investigate interactions with cGAS, mitochondrial alterations, and pro-inflammatory pathway activation. Renal sympathetic nerve activity and heart rate variability were measured to assess sympathetic output, alongside evaluations of cardiac function in HF mice.

RESULTS

In HF model mice, SGLT2 levels are markedly raised in SFO ECs, disrupting mitochondrial function and elevating oxidative stress. SGLT2 knockdown preserved mitochondrial integrity and function, reduced inflammation, and highlighted the influence of SGLT2 on mitochondrial health. SGLT2's interaction with cGAS prevented its ubiquitination and degradation, amplifying neuroinflammation and HF progression. Conversely, Empagliflozin counteracted these effects, suggesting that targeting the SGLT2-cGAS interaction as a novel HF treatment avenue.

CONCLUSION

This study revealed that SGLT2 directly reduced cGAS degradation in brain ECs, enhancing neuroinflammation in the SFO, and promoting sympathoexcitation and myocardial remodeling. The significance of the central SGLT2-cGAS interaction in cardiovascular disease mechanisms is emphasized.

Emerging Perspectives on the Impact of Diabetes Mellitus and Anti-Diabetic Drugs on Premenstrual Syndrome. A Narrative Review

Diabetes mellitus (DM) and premenstrual syndrome (PMS) are global health challenges. Both disorders are often linked to a range of physical and psychological symptoms that significantly impact the quality of life of many women. Yet, the exact relation between DM and PMS is not clear, and the management of both conditions poses a considerable challenge. In this review, we aimed to investigate the interplay between DM, anti-diabetic drugs, and the different theories and symptoms of PMS. Female sex hormones are implicated in the pathophysiology of PMS and can also impair blood glucose control. In addition, patients with diabetes face a higher susceptibility to anxiety and depression disorders, with a significant number of patients experiencing symptoms such as fatigue and difficulty concentrating, which are reported in patients with PMS as well. Complications related to diabetic medications, such as hypoglycemia (with sulfonylurea) and fluid retention (with thiazolidinediones) may also mediate PMS-like symptoms. DM can, in addition, disturb the normal gut microbiota (GM), with a consequent loss of beneficial GM metabolites that guard against PMS, particularly the short-chain fatty acids and serotonin. Among the several available anti-diabetic drugs, those (1) with an anti-inflammatory potential, (2) that can preserve the beneficial GM, and (3) possessing a lower risk for hypoglycemia, might have a favorable outcome in PMS women. Yet, well-designed clinical trials are needed to investigate the anti-diabetic drug(s) of choice for patients with diabetes and PMS.

Sodium glucose cotransporter-2 inhibitors and heart disease: Current perspectives

Sodium glucose cotransporter-2 inhibitors (SGLT-2i) are antidiabetic medications with remarkable cardiovascular (CV) benefits proven by multiple randomised controlled trials and real-world data. These drugs are also useful in the prevention of CV disease (CVD) in patients with diabetes mellitus (DM). Although DM as such is a huge risk factor for CVD, the CV benefits of SGLT-2i are not just because of antidiabetic effects. These molecules have proven beneficial roles in prevention and management of nondiabetic CVD and renal disease as well. There are various molecular mechanisms for the organ protective effects of SGLT-2i which are still being elucidated. Proper understanding of the role of SGLT-2i in prevention and management of CVD is important not only for the cardiologists but also for other specialists caring for various illnesses which can directly or indirectly impact care of heart diseases. This clinical review compiles the current evidence on the rational use of SGLT-2i in clinical practice.

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 and SGLT1 inhibitors suppress the activities of the RVLM neurons in newborn Wistar rats

Hypertension is well-known to often coexist with diabetes mellitus (DM) in humans. Treatment with sodium-glucose cotransporter 2 (SGLT2) inhibitors has been shown to decrease both the blood glucose and the blood pressure (BP) in such patients. Some reports show that SGLT2 inhibitors improve the BP by decreasing the activities of the sympathetic nervous system. Therefore, we hypothesized that SGLT2 inhibitors might alleviate hypertension via attenuating sympathetic nervous activity. Combined SGLT2/SGLT1 inhibitor therapy is also reported as being rather effective for decreasing the BP. In this study, we examined the effects of SGLT2 and SGLT1 inhibitors on the bulbospinal neurons of the rostral ventrolateral medulla (RVLM). To investigate whether bulbospinal RVLM neurons are sensitive to SGLT2 and SGLT1 inhibitors, we examined the changes in the neuronal membrane potentials (MPs) of these neurons using the whole-cell patch-clamp technique during superfusion of the cells with the SGLT2 and SGLT1 inhibitors. A brainstem-spinal cord preparation was used for the experiments. Our results showed that superfusion of the RVLM neurons with SGLT2 and SGLT1 inhibitor solutions induced hyperpolarization of the neurons. Histological examination revealed the presence of SGLT2s and SGLT1s in the RVLM neurons, and also colocalization of SGLT2s with SGLT1s. These results suggest the involvement of SGLT2s and SGLT1s in regulating the activities of the RVLM neurons, so that SGLT2 and SGLT1 inhibitors may inactivate the RVLM neurons hyperpolarized by empagliflozin. SGLT2 and SGLT1 inhibitors suppressed the activities of the bulbospinal RVLM neurons in the brainstem-spinal preparations, suggesting the possibilities of lowering BP by decreasing the sympathetic nerve activities. RVLM, rostral ventrolateral medulla. IML, intralateral cell column. aCSF, artificial cerebrospinal fluid.

Sodium-glucose cotransporter type 2 inhibitors and cardiac arrhythmias

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

The Impact of SGLT2 Inhibitors in the Heart and Kidneys Regardless of Diabetes Status

Chronic Kidney Disease (CKD) and Cardiovascular Disease (CVD) are two devastating diseases that may occur in nondiabetics or individuals with diabetes and, when combined, it is referred to as cardiorenal disease. The impact of cardiorenal disease on society, the economy and the healthcare system is enormous. Although there are numerous therapies for cardiorenal disease, one therapy showing a great deal of promise is sodium-dependent glucose cotransporter 2 (SGLT2) inhibitors. The SGLT family member, SGLT2, is often implicated in the pathogenesis of a range of diseases, and the dysregulation of the activity of SGLT2 markedly effects the transport of glucose and sodium across the luminal membrane of renal cells. Inhibitors of SGLT2 were developed based on the antidiabetic action initiated by inhibiting renal glucose reabsorption, thereby increasing glucosuria. Of great medical significance, large-scale clinical trials utilizing a range of SGLT2 inhibitors have demonstrated both metabolic and biochemical benefits via numerous novel mechanisms, such as sympathoinhibition, which will be discussed in this review. In summary, SGLT2 inhibitors clearly exert cardio-renal protection in people with and without diabetes in both preclinical and clinical settings. This exciting class of inhibitors improve hyperglycemia, high blood pressure, hyperlipidemia and diabetic retinopathy via multiple mechanisms, of which many are yet to be elucidated.

Management of Type 2 Diabetes in Frail Older Adults

Aging is one of the most important factors associated with the dramatic increase in the prevalence of type 2 diabetes mellitus (T2DM) globally. In addition to traditional micro- and macrovascular complications, diabetes mellitus (DM) in older adults is of great importance due to its independent relationship with frailty, which is defined as a decline in functional reserves and vulnerability to stressors. Frailty assessment enables the determination of biological age, thus predicting potential complications in older adults and identifying tailored treatment strategies. Although the latest guidelines have acknowledged the frailty concept and provided recommendations specific to this subgroup of older adults, frail older adults are particularly considered only as anorexic, malnourished people for whom relaxed treatment targets should be set. However, this approach bypasses other metabolic phenotypes in the context of diabetes and frailty. Recently, a spectrum of metabolic phenotypes in the context of frailty in DM was suggested, and the two edges of this spectrum were defined as "anorexic malnourished (AM)" and "sarcopenic obese (SO)." These two edges were suggested to require different strategies: Opposite to the AM phenotype requiring less stringent targets and de-intensification of treatments, tight blood glucose control with agents promoting weight loss was recommended in the SO group. Our suggestion is that, regardless of their phenotype, weight loss should not be the primary goal in DM management in older adults who are overweight or obese, because of the increased malnutrition prevalence in older adults suffering from DM compared with standard older adults. Furthermore, overweight older adults have been reported to have the lowest risk of mortality compared with other groups. On the other hand, obese older individuals may benefit from intensive lifestyle interventions including caloric restriction and regular exercise with the assurance of at least 1 g/kg/day high-quality protein intake. Besides metformin (MF), sodium-glucose cotransporter-2 inhibitors (SGLT-2i) or glucagon-like peptide-1 receptor agonists (GLP-1RA) should be considered in appropriate SO cases, due to high evidence of cardiorenal benefits. MF should be avoided in the AM phenotype due to their weight loss property. Although weight loss is not desired in AM phenotype, SGLT-2i may still be preferred with close follow-up in certain individuals demonstrating high cardiovascular disease (CVD) risk. Of note, SGLT-2i should be considered earlier in the diabetes treatment in both groups due to their multiple benefits, i.e., organ protective effects, the potential to reduce polypharmacy, and improve frailty status. The concept of different metabolic phenotypes in frail older adults with diabetes once again shows "one size fits all" cannot be applied in geriatric medicine, and a tailored, individualized approach should be adopted to get the highest benefit from treatments.

Elnosary M, L. Ashour M, M. Abd El-Moneam N, A. Shreadah M. Flavonoids Biosynthesis in Plants as a Defense Mechanism: Role and Function Concerning Pharmacodynamics and Pharmacokinetic Properties

Flavonoids are a major class of secondary metabolites that comprises more than 6000 compounds that have been identified. They are biosynthesized via the phenylpropanoid metabolic pathway that involves groups of enzymes such as isomerases, hydroxylases, and reductases that greatly affect the determination of the flavonoid skeleton. For example, transferase enzymes responsible for the modification of sugar result in changes in the physiological activity of the flavonoids and changes in their physical properties, such as solubility, reactivity, and interaction with cellular target molecules, which affect their pharmacodynamics and pharmacokinetic properties. In addition, flavonoids have diverse biological activities such as antioxidants, anticancer, and antiviral in managing Alzheimer’s disease. However, most marine flavonoids are still incompletely discovered because marine flavonoid biosynthesis is produced and possesses unique substitutions that are not commonly found in terrestrial bioactive compounds. The current chapter will illustrate the importance of flavonoids’ role in metabolism and the main difference between marine and terrestrial flavonoids.

The Neuronal and Non-Neuronal Pathways of Sodium-Glucose Cotransporter-2 Inhibitor on Body Weight-Loss and Insulin Resistance

With the emergence of sodium-glucose cotransporter 2 inhibitors (SGLT2i), the treatment of type 2 diabetes mellitus (T2DM) has achieved a new milestone, of which the insulin-independent mechanism could produce weight loss, improve insulin resistance (IR) and exert other protective effects. Besides the well-acknowledged biochemical processes, the dysregulated balance between sympathetic and parasympathetic activity may play a significant role in IR and obesity. Weight loss caused by SGLT-2i could be achieved via activating the liver-brain-adipose neural axis in adipocytes. We previously demonstrated that SGLT-2 are widely expressed in central nervous system (CNS) tissues, and SGLT-2i could inhibit central areas associated with autonomic control through unidentified pathways, indicating that the role of the central sympathetic inhibition of SGLT-2i on blood pressure and weight loss. However, the exact pathway of SGLT2i related to these effects and to what extent it depends on the neural system are not fully understood. The evidence of how SGLT-2i interacts with the nervous system is worth exploring. Therefore, in this review, we will illustrate the potential neurological processes by which SGLT2i improves IR in skeletal muscle, liver, adipose tissue, and other insulin-target organs via the CNS and sympathetic nervous system/parasympathetic nervous system (SNS/PNS).

The Mechanism of Sodium-Glucose Cotransporter-2 Inhibitors in Reducing Uric Acid in Type 2 Diabetes Mellitus

Hyperuricemia is a common comorbidity in patients with type 2 diabetes mellitus (T2DM), as insulin resistance (IR) or hyperinsulinemia is associated with higher serum uric acid (SUA) levels due to decreased uric acid (UA) secretion, and SUA vice versa is an important risk factor that promotes the occurrence and progression of T2DM and its complications. Growing evidence suggests that sodium-glucose cotransporter 2 inhibitors (SGLT-2i), a novel anti-diabetic drug initially developed to treat T2DM, may exert favorable effects in reducing SUA. Currently, one of the possible mechanisms is that SGLT2i increases urinary glucose excretion, probably inhibiting glucose transport 9 (GLUT9)-mediated uric acid reabsorption in the collecting duct, resulting in increased uric acid excretion in exchange for glucose reabsorption. Regardless of this possible mechanism, the underlying comprehensive mechanisms remain poorly elucidated. Therefore, in the present review, a variety of other potential mechanisms will be covered to identify the therapeutic role of SGLT-2i in hyperuricemia.

Metabolic Syndrome-Related Kidney Injury: A Review and Update

Metabolic syndrome (MetS) includes visceral obesity, hyperglycemia, dyslipidemia, and hypertension. The prevalence of MetS is 20-25%, which is an important risk factor for chronic kidney disease (CKD). MetS causes effects on renal pathophysiology, including glomerular hyperfiltration, RAAS, microalbuminuria, profibrotic factors and podocyte injury. This review compares several criteria of MetS and analyzes their differences. MetS and the pathogenesis of CKD includes insulin resistance, obesity, dyslipidemia, inflammation, oxidative stress, and endothelial dysfunction. The intervention of MetS-related renal damage is the focus of this article and includes controlling body weight, hypertension, hyperglycemia, and hyperlipidemia, requiring all components to meet the criteria. In addition, interventions such as endoplasmic reticulum stress, oxidative stress, gut microbiota, body metabolism, appetite inhibition, podocyte apoptosis, and mesenchymal stem cells are reviewed.

Col4a3-/- Mice on Balb/C Background Have Less Severe Cardiorespiratory Phenotype and SGLT2 Over-Expression Compared to 129x1/SvJ and C57Bl/6 Backgrounds

Alport syndrome (AS) is a hereditary renal disorder with no etiological therapy. In the preclinical Col4a3-/- model of AS, disease progression and severity vary depending on mouse strain. The sodium-glucose cotransporter 2 (SGLT2) is emerging as an attractive therapeutic target in cardiac/renal pathologies, but its application to AS remains untested. This study investigates cardiorespiratory function and SGLT2 renal expression in Col4a3-/- mice from three different genetic backgrounds, 129x1/SvJ, C57Bl/6 and Balb/C. male Col4a3-/- 129x1/SvJ mice displayed alterations consistent with heart failure with preserved ejection fraction (HFpEF). Female, but not male, C57Bl/6 and Balb/C Col4a3-/- mice exhibited mild changes in systolic and diastolic function of the heart by echocardiography. Male C57Bl/6 Col4a3-/- mice presented systolic dysfunction by invasive hemodynamic analysis. All strains except Balb/C males demonstrated alterations in respiratory function. SGLT2 expression was significantly increased in AS compared to WT mice from all strains. However, cardiorespiratory abnormalities and SGLT2 over-expression were significantly less in AS Balb/C mice compared to the other two strains. Systolic blood pressure was significantly elevated only in mutant 129x1/SvJ mice. The results provide further evidence for strain-dependent cardiorespiratory and hypertensive phenotype variations in mouse AS models, corroborated by renal SGLT2 expression, and support ongoing initiatives to develop SGLT2 inhibitors for the treatment of AS.