Sodium-glucose cotransporter 2 inhibitors and mitochondrial functions: state of the art

Adipose tissue as target of environmental toxicants: focus on mitochondrial dysfunction and oxidative inflammation in metabolic dysfunction-associated steatotic liver disease

Obesity, diabetes, and their cardiovascular and hepatic comorbidities are alarming public health issues of the twenty-first century, which share mitochondrial dysfunction, oxidative stress, and chronic inflammation as common pathophysiological mechanisms. An increasing body of evidence links the combined exposure to multiple environmental toxicants with the occurrence and severity of metabolic diseases. Endocrine disruptors (EDs) are ubiquitous chemicals or mixtures with persistent deleterious effects on the living organisms beyond the endocrine system impairment; in particular, those known as metabolism-disrupting chemicals (MDCs), increase the risk of the metabolic pathologies in adult organism or its progeny. Being largely lipophilic, MDCs mainly target the adipose tissue and elicit mitochondrial dysfunction by interfering with mitochondrial bioenergetics, biogenesis, dynamics and/or other functions. Plastics, when broken down into micro- and nano-plastics (MNPs), have been detected in several human tissues, including the liver. The harmful interplay between inflammatory and redox processes, which mutually interact in a positive feed-back loop, hence the term oxidative inflammation ("OxInflammation"), occurs both at systemic and organ level. In both liver and adipose tissue, oxinflammation contributes to the progression of the metabolic dysfunction-associated steatotic liver disease (MASLD). Moreover, it has been reported that individuals with MASLD may be more susceptible to the harmful effects of toxicants (mainly, those related to mitochondria) and that chronic exposure to EDs/MDCs or MNPs may play a role in the development of the disease. While liver has been systematically investigated as major target organ for ambient chemicals, surprisingly, less information is available in the literature with respect to the adipose tissue. In this narrative review, we delve into the current literature on the most studied environmental toxicants (bisphenols, polychlorinated biphenyls, phthalates, tolylfluanid and tributyltin, per-fluoroalkyl and polyfluoroalkyl substances, heavy metals and MNPs), summarize their deleterious effects on adipose tissue, and address the role of dysregulated mitochondria and oxinflammation, particularly in the setting of MASLD.

GLP-1RA and SGLT2i Medications for Type 2 Diabetes and Alzheimer Disease and Related Dementias

Importance

The association between glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT2is) and risk of Alzheimer disease and related dementias (ADRD) remains to be confirmed.

Objective

To assess the risk of ADRD associated with GLP-1RAs and SGLT2is in people with type 2 diabetes (T2D).

Design, Setting, and Participants

This target trial emulation study used electronic health record data from OneFlorida+ Clinical Research Consortium from January 2014 to June 2023. Patients were 50 years or older with T2D and no prior diagnosis of ADRD or antidementia treatment. Among the 396 963 eligible patients with T2D, 33 858 were included in the GLP-1RA vs other glucose-lowering drug (GLD) cohort, 34 185 in the SGLT2i vs other GLD cohort, and 24 117 in the GLP-1RA vs SGLT2i cohort.

Exposures

Initiation of treatment with a GLP-1RA, SGLT2i, or other second-line GLD.

Main Outcomes and Measures

ADRD was identified using clinical diagnosis codes. Hazard ratios (HRs) with 95% CIs were estimated using Cox proportional hazard regression models with inverse probability of treatment weighting (IPTW) to adjust for potential confounders.

Results

This study included 33 858 patients in the GLP-1RA vs other GLD cohort (mean age, 65 years; 53.1% female), 34 185 patients in the SGLT2i vs other GLD cohort (mean age, 65.8 years; 49.3% female), and 24 117 patients in the GLP-1RA vs SGLT2i cohort (mean age, 63.8 years; 51.7% female). In IPTW-weighted cohorts, the incidence rate of ADRD was lower in GLP-1RA initiators compared with other GLD initiators (rate difference [RD], -2.26 per 1000 person-years [95% CI, -2.88 to -1.64]), yielding an HR of 0.67 (95% CI, 0.47-0.96). SGLT2i initiators had a lower incidence than other GLD initiators (RD, -3.05 per 1000 person-years [95% CI, -3.68 to -2.42]), yielding an HR of 0.57 (95% CI, 0.43-0.75). There was no difference between GLP-1RAs and SGLT2is, with an RD of -0.09 per 1000 person-years (95% CI, -0.80 to 0.63) and an HR of 0.97 (95% CI, 0.72-1.32).

Conclusion and Relevance

In people with T2D, both GLP-1RAs and SGLT2is were statistically significantly associated with decreased risk of ADRD compared with other GLDs, and no difference was observed between both drugs.

Assessment of Gliflozins prescribing pattern in a United Arab Emirates tertiary-level care hospital

Background

Sodium-Glucose Co-Transporter 2 (SGLT2) inhibitors, known as Gliflozins, have demonstrated efficacy in managing type 2 diabetes mellitus (T2DM) and providing cardiovascular and renal benefits. Given the prevalence of diabetes, heart failure (HF), and chronic kidney disease (CKD) in the UAE, there is a need to evaluate the prescribing patterns of Gliflozins in these population. The objective of this study was to explore the relationship between Gliflozins use for patients who were admitted to the hospital at least once from 2021 to 2023 and different clinical factors.

Methods

A retrospective medication review was conducted from 2021 to 2023 at tertiary-level care hospital in Ajman, UAE. Data were collected on prescribed Gliflozins, patient demographic information, BMI, HbA1c levels, and comorbidities (HF, CKD). Chi-square tests and binary logistic regression were used to explore associations between Gliflozin use and clinical factors.

Results

Out of the 255 patients' data collected, Gliflozin use was significantly associated with obesity (p = 0.002), higher HbA1c levels (p < 0.001), and comorbidities, particularly HF (61.5% of HF patients) and CKD. The use of Gliflozins increased each year. Patients with HF were 8.03 times more likely to use Gliflozins, and those with diabetes were 6.86 times more likely, underscoring the multidimensional role of these medications.

Conclusion

Gliflozin prescribing patterns in the UAE reflect global trends, with increased use among patients with diabetes, HF, and CKD. Further research is recommended to explore factors influencing prescription practices and optimize Gliflozin therapy if gliflozins use considerably increase in new diagnosis of diabetes and CKD even in mild conditions.

Metabolic reprogramming of peritoneal mesothelial cells in peritoneal dialysis-associated fibrosis: therapeutic targets and strategies

Peritoneal dialysis (PD) is considered a life-saving treatment for end-stage renal disease. However, prolonged PD use can lead to the development of peritoneal fibrosis (PF), diminishing its efficacy. Peritoneal mesothelial cells (PMCs) are key initiators of PF when they become damaged. Exposure to high glucose‑based peritoneal dialysis fluids (PDFs) contributes to PF development by directly affecting highly metabolically active PMCs. Recent research indicates that PMCs undergo metabolic reprogramming when exposed to high-glucose PDFs, including enhanced glycolysis, impaired oxidative phosphorylation, abnormal lipid metabolism, and mitochondrial dysfunction. Although this metabolic transition temporarily compensates for the cellular damage and maintains energy levels, its long-term impact on peritoneal tissue is concerning. Multiple studies have identified a close association between this shift in energy metabolism and PF, and may promote the progression of PF through various molecular mechanisms. This review explores recent findings regarding the role and mechanism of PMC metabolic reprogramming in PF progression. Moreover, it provides a summary of potential therapeutic strategies aimed at various metabolic processes, including glucose metabolism, lipid metabolism, and mitochondrial function. The review establishes that targeting metabolic reprogramming in PMCs may be a novel strategy for preventing and treating PD-associated fibrosis.

Empagliflozin in diabetic cardiomyopathy: elucidating mechanisms, therapeutic potentials, and future directions

Diabetic cardiomyopathy (DCM) represents a significant health burden, exacerbated by the global increase in type 2 diabetes mellitus (T2DM). This condition contributes substantially to the morbidity and mortality associated with diabetes, primarily through myocardial dysfunction independent of coronary artery disease. Current treatment strategies focus on managing symptoms rather than targeting the underlying pathophysiological mechanisms, highlighting a critical need for specific therapeutic interventions. This review explores the multifaceted role of empagliflozin, a sodium-glucose cotransporter 2 (SGLT-2) inhibitor, in addressing the complex etiology of DCM. We discuss the key mechanisms by which hyperglycemia contributes to cardiac dysfunction, including oxidative stress, mitochondrial impairment, and inflammation, and how empagliflozin mitigates these effects. Empagliflozin's effects on reducing hospitalization for heart failure and potentially lowering cardiovascular mortality mark it as a promising candidate for DCM management. By elucidating the underlying mechanisms through which empagliflozin operates, this review underscores its therapeutic potential and paves the way for future research into its broader applications in diabetic cardiac care. This synthesis aims to foster a deeper understanding of DCM and encourage the integration of empagliflozin into treatment paradigms, offering hope for improved outcomes in patients suffering from this debilitating condition.

Empagliflozin Ameliorates the Oxidative Stress Profile in Type 2 Diabetic Patients with Heart Failure and Reduced Ejection Fraction: Results of a Randomized, Double-blind, Placebo-controlled Study

INTRODUCTION

In the present study, we evaluated the impact of empagliflozin on serum levels of oxidative stress parameters in individuals with type 2 diabetes (T2DM) who also suffer from heart failure with Reduced Ejection Fraction (HFrEF).

METHODS

In this prospective, single-center clinical trial, 80 patients with T2DM and HFrEF, stabilized on guideline-directed heart failure therapy and classified as New York Heart Association functional (NYHA) functional classes II or III, were randomized to receive either empagliflozin (10 mg/daily) or a matching placebo for a duration of 12 weeks. Serum levels of malondialdehyde (MDA), along with the activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx), were measured at baseline and after the 12-week treatment period.

RESULTS

The baseline demographic and clinical characteristics of the randomized patients were comparable across the study groups. As anticipated, empagliflozin demonstrated a significant reduction in fasting blood glucose (FBG) and glycated hemoglobin (HbA1c) compared to the placebo after 12 weeks of treatment. Additionally, in comparison to the placebo, empagliflozin significantly increased the antioxidant capacity by elevating serum activity of SOD and GPx, while reducing oxidative damage, as evidenced by diminished MDA levels. Empagliflozin-treated patients also experienced greater improvement in their NYHA functional classes by week 12, though no significant changes in Left Ventricular Ejection Fraction (LVEF) were observed.

CONCLUSION

The findings of this study shed light on the potential mechanisms through which SGLT2 inhibitors exert their beneficial effects on clinical outcomes in diabetic patients with HFrEF. This provides compelling evidence supporting the cardio-protective of SGLT2 inhibitors in this patient population.

CLINICAL TRIAL REGISTRATION NUMBER

The trial was registered at the Iranian Registry of Clinical Trials (https://irct.behdasht.gov.ir/trial/72825, identifier code: IRCT20120215009014N484). Registration date: 2022-09-30.

Mitochondrial Dysfunction in Cardiac Disease: The Fort Fell

Myocardial cells and the extracellular matrix achieve their functions through the availability of energy. In fact, the mechanical and electrical properties of the heart are heavily dependent on the balance between energy production and consumption. The energy produced is utilized in various forms, including kinetic, dynamic, and thermal energy. Although total energy remains nearly constant, the contribution of each form changes over time. Thermal energy increases, while dynamic and kinetic energy decrease, ultimately becoming insufficient to adequately support cardiac function. As a result, toxic byproducts, unfolded or misfolded proteins, free radicals, and other harmful substances accumulate within the myocardium. This leads to the failure of crucial processes such as myocardial contraction-relaxation coupling, ion exchange, cell growth, and regulation of apoptosis and necrosis. Consequently, both the micro- and macro-architecture of the heart are altered. Energy production and consumption depend on the heart's metabolic resources and the functional state of the cardiac structure, including cardiomyocytes, non-cardiomyocyte cells, and their metabolic and energetic behavior. Mitochondria, which are intracellular organelles that produce more than 95% of ATP, play a critical role in fulfilling all these requirements. Therefore, it is essential to gain a deeper understanding of their anatomy, function, and homeostatic properties.

Extrarenal Benefits of SGLT2 Inhibitors in the Treatment of Cardiomyopathies

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have emerged as pivotal medications for heart failure, demonstrating remarkable cardiovascular benefits extending beyond their glucose-lowering effects. The unexpected cardiovascular advantages have intrigued and prompted the scientific community to delve into the mechanistic underpinnings of these novel actions. Preclinical studies have generated many mechanistic theories, ranging from their renal and extrarenal effects to potential direct actions on cardiac muscle cells, to elucidate the mechanisms linking these drugs to clinical cardiovascular outcomes. Despite the strengths and limitations of each theory, many await validation in human studies. Furthermore, whether SGLT2 inhibitors confer therapeutic benefits in specific subsets of cardiomyopathies akin to their efficacy in other heart failure populations remains unclear. By examining the shared pathological features between heart failure resulting from vascular diseases and other causes of cardiomyopathy, certain specific molecular actions of SGLT2 inhibitors (particularly those targeting cardiomyocytes) would support the concept that these medications will yield therapeutic benefits across a broad range of cardiomyopathies. This article aims to discuss the important mechanisms of SGLT2 inhibitors and their implications in hypertrophic and dilated cardiomyopathies. Furthermore, we offer insights into future research directions for SGLT2 inhibitor studies, which hold the potential to further elucidate the proposed biological mechanisms in greater detail.

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.

Sodium glucose cotransporter 2 inhibitor suppresses renal injury in rats with renal congestion

Renal congestion is an issue of cardiorenal syndrome in patients with heart failure. Recent clinical and basic studies suggest a renoprotective potential of sodium-glucose cotransporter (SGLT) 2 inhibitors. However, the effect on renal congestion and its mechanism is not fully understood. Thus, we aimed to clarify the effect of SGLT inhibition in a renal congestion model. Renal congestion was induced in the left kidney of male Sprague-Dawley rats by ligation of the inferior vena cava between the renal veins. The SGLT2 inhibitor tofogliflozin or vehicle was orally administered daily from the day before IVC ligation until two days after surgery. On the third postoperative day, both the right control kidney and the left congested kidney were harvested and analyzed. Kidney weight and water content was increased, and renal injury and fibrosis were observed in the left congested kidney. Kidney weight gain and hydration were improved with tofogliflozin treatment. Additionally, this treatment effectively reduced renal injury and fibrosis, particularly in the renal cortex. SGLT2 expression was observed in the congested kidney, but suppressed in the damaged tubular cells. Molecules associated with inflammation were increased in the congested kidney and reversed by tofogliflozin treatment. Mitochondrial dysfunction provoked by renal congestion was also improved by tofogliflozin treatment. Tofogliflozin protects against renal damage induced by renal congestion. SGLT2 inhibitors could be a candidate strategy for renal impairment associated with heart failure.

Hepatic benefits of sodium-glucose cotransporter 2 inhibitors in liver disorders

Diabetic patients are at higher risk of liver dysfunction compared with the normal population. Thus, using hypoglycemic agents to improve liver efficiency is important in these patients. Sodium-glucose cotransporters-2 inhibitors (SGLT2i) are newly developed antidiabetic drugs with potent glucose-lowering effects. However, recent limited evidence suggests that they have extra-glycemic benefits and may be able to exert protective effects on the liver. Hence, these drugs could serve as promising pharmacological agents with multiple benefits against different hepatic disorders. In this review, the current knowledge about the possible effects of SGLT2 inhibitors on different forms of liver complications and possible underlying mechanisms are discussed.