Can Metformin Exert as an Active Drug on Endothelial Dysfunction in Diabetic Subjects?

Comprehensive treatment of diabetic endothelial dysfunction based on pathophysiological mechanism

Vascular endothelium is integral to the regulation of vascular homeostasis and maintenance of normal arterial function in healthy individuals. Endothelial dysfunction is a significant contributor to the advancement of atherosclerosis, which can precipitate cardiovascular complications. A notable correlation exists between diabetes and endothelial dysfunction, wherein chronic hyperglycemia and acute fluctuations in glucose levels exacerbate oxidative stress. This results in diminished nitric oxide synthesis and heightened production of endothelin-1, ultimately leading to endothelial impairment. In clinical settings, it is imperative to implement appropriate therapeutic strategies aimed at enhancing endothelial function to prevent and manage diabetes-associated vascular complications. Various antidiabetic agents, including insulin, GLP-1 receptor agonists, sulfonylureas, DPP-4 inhibitors, SGLT2 inhibitors, α-glucosidase inhibitors, thiazolidinediones (TZDs), and metformin, are effective in mitigating blood glucose variability and improving insulin sensitivity by lowering postprandial glucose levels. Additionally, traditional Chinese medicinal compounds, such as turmeric extract, resveratrol, matrine alkaloids, tanshinone, puerarin, tanshinol, paeonol, astragaloside, berberine, and quercetin, exhibit hypoglycemic properties and enhance vascular function through diverse mechanisms. Consequently, larger randomized controlled trials involving both pharmacological and herbal interventions are essential to elucidate their impact on endothelial dysfunction in patients with diabetes. This article aims to explore a comprehensive approach to the treatment of diabetic endothelial dysfunction based on an understanding of its pathophysiology.

Metformin's Effects on Cognitive Function from a Biovariance Perspective: A Narrative Review

This study examines the effects of metformin on brain functions focusing on the variability of the results reported in the literature. While some studies suggest that metformin may have neuroprotective effects in diabetic patients, others report an insignificant impact of metformin on cognitive function, or even a negative effect. We propose that this inconsistency may be due to intrinsic cellular-level variability among individuals, which we term "biovariance". Biovariance persists even in demographically homogeneous samples due to complex and stochastic biological processes. Additionally, the complex metabolic actions of metformin, including its influence on neuroenergetics and neuronal survival, may produce different effects depending on individual metabolic characteristics.

Metformin in Antiviral Therapy: Evidence and Perspectives

Metformin, a widely used antidiabetic medication, has emerged as a promising broad-spectrum antiviral agent due to its ability to modulate cellular pathways essential for viral replication. By activating AMPK, metformin depletes cellular energy reserves that viruses rely on, effectively limiting the replication of pathogens such as influenza, HIV, SARS-CoV-2, HBV, and HCV. Its role in inhibiting the mTOR pathway, crucial for viral protein synthesis and reactivation, is particularly significant in managing infections caused by HIV, CMV, and EBV. Furthermore, metformin reduces oxidative stress and reactive oxygen species (ROS), which are critical for replicating arboviruses such as Zika and dengue. The drug also regulates immune responses, cellular differentiation, and inflammation, disrupting the life cycle of HPV and potentially other viruses. These diverse mechanisms suppress viral replication, enhance immune system functionality, and contribute to better clinical outcomes. This multifaceted approach highlights metformin's potential as an adjunctive therapy in treating a wide range of viral infections.

The positive implication of natural antioxidants on oxidative stress-mediated diabetes mellitus complications

The complementary intervention to modulate diabetes mellitus (DM) metabolism has recently brought the global attention, since DM has become among the global burden diseases. Where, several related pathways elevate the production of superoxide in consequences. For example, the flux of glycation-derived end products (AGEs) could lead to the deactivation of insulin signaling pathways. In that context, many vitamins and phytochemicals in natural sources have high antioxidant impacts that reduce oxidative stress and cell damages. These chemicals could be applied as bioactive antidiabetic agents. Their mode of actions could be from regulating the intracellular reactive oxygen species (ROS) which cause several pro-inflammatory pathways related to the oxidative stress (OS) and DM. Besides, they have a great potential to control the epigenetic mutations and hyperglycemia and help in back the blood glucose to the normal level. Therefore, the current review addresses the important role of natural functional antioxidants in DM management and its association with its OS complications.

Curcumin is a potential therapeutic agent that ameliorates diabetes among non-alcoholic fatty liver disease coexist with type 2 diabetes

Type 2 diabetes mellitus (T2DM) and non-alcoholic fatty liver disease (NAFLD) harmonize and act synergistically in clinical practices. About 70–80% of diabetic patients develop NAFLD. At the same time, NAFLD existence increases T2DM development. Meanwhile, the presence of T2DM increases the progression to liver disease such as NAFLD, and to non-alcoholic steatohepatitis (NASH). The most prevalent chronic liver disease worldwide is a NAFLD. NAFLD and (T2DM) have a two-way pathophysiologic relationship, with the latter driving the development of the former into NASH. Nonetheless, NASH enhances the threat of cirrhosis as well as hepatocellular carcinoma (HCC), both cases in turn need transplantation of the liver. The only treatment for NAFLD is still lifestyle management because there are no FDA-approved drugs for the condition. In the current study, we review how curcumin (a naturally occurring phytopolyphenol pigment) treats NAFLD. Also we showed broad insights on curcumin-based therapy, by severe reduction of hepatic inflammation. Thus, our review showed that curcumin ingestion considerably decreased glycemic parameters (fasting blood glucose, glycosylated hemoglobin, insulin resistance index (HOMA-IR), and free fatty acids) and adipocyte-fatty acid binding protein (A-FABP), and adipokine released from adipocytes. Clinical trials are needed to evaluate the effects of curcumin and its specific dosage on liver enzymes, glycemic consequences, among NAFLD coexist with T2DM patients.

Metformin: Beyond Type 2 Diabetes Mellitus

Metformin was developed from an offshoot of Guanidine. It is known to be the first-line medication for type 2 diabetes mellitus, polycystic ovarian syndrome, and weight reduction. Metformin has also been shown to have effectiveness in the management of non-alcoholic fatty liver disease (NAFLD), liver cirrhosis, and various carcinomas like hepatocellular, colorectal, prostate, breast, urinary bladder, blood, melanoma, bone, skin, lung and so on. This narrative review focuses on the effect of metformin on non-alcoholic fatty liver disease, liver cirrhosis, and hepatocellular carcinoma. The search platforms for the topic were PubMed, Scopus, and Google search engine. Critical words for searching included 'Metformin,' AND 'Indications of Metformin,' AND 'Non-Alcoholic Fatty Liver Disease,' AND 'Metformin mechanism of action,' AND 'NAFLD management,' AND 'NAFLD and inflammation,' AND 'Metformin and insulin,' AND 'Metformin and inflammation,' AND 'Liver cirrhosis,' AND 'Hepatocellular carcinoma.' Lifestyle modification and the use of hypoglycemic agents can help improve liver conditions. Metformin has several mechanisms that enhance liver health, including reducing reactive oxygen species, nuclear factor kappa beta (NF-κB), liver enzymes, improving insulin sensitivity, and improving hepatic cell lipophagy. Long-term use of metformin may cause some adverse effects like lactic acidosis and gastrointestinal disturbance. Metformin long-term overdose may lead to a rise in hydrogen sulfide in liver cells, which calls for pharmacovigilance. Drug regulating authorities should provide approval for further research, and national and international guidelines need to be developed for liver diseases, perhaps with the inclusion of metformin as part of the management regime.

Gastrointestinal adverse events of metformin treatment in patients with type 2 diabetes mellitus: a systematic review and meta-analysis with meta-regression of observational studies

INTRODUCTION

Metformin is the most prescribed medication for type 2 diabetes mellitus (T2DM); there is a well-established link with the elevated incidence of gastrointestinal (GI) adverse events (AE) limiting its administration or intensification.

OBJECTIVES

The objective of this systematic review and meta-analysis of observational studies was to evaluate the pooled incidence of GI AE related to metformin use in patients with T2DM.

MATERIALS AND METHODS

PUB MED/CINAHL/Web of Science/Scopus were searched from database inception until 29.07.2024 for observational studies in English describing the frequency of GI AE in patients with T2DM treated with metformin. Random-effects meta-analyses were used to derive effect sizes: event rates.

RESULTS

From 7019 publications, we identified 211 potentially eligible full-text articles. Ultimately, 21 observational studies were included in the meta-analysis. The prevalence of GI AE was as follows: diarrhea 6.9% (95% CI: 0.038-0.123), bloating 6,2% (95% CI: 0.020-0.177), abdominal pain 5,3% (95% CI: 0.003-0.529), vomiting 2.4% (95%: CI 0.007-0.075), constipation 1.1% (95%: CI 0.001-0.100). The incidence of bloating (coefficient -4.46; p < 0.001), diarrhea (coefficient -1.17; p = 0.0951) abdominal pain (coefficient -2.80; p = 0.001), constipation (coefficient -5.78; p = 0.0014) and vomiting (coefficient -2.47; p < 0.001) were lower for extended release (XR) metformin than metformin immediate release (IR) formulation.

CONCLUSIONS

This study highlights the prevalence of GI AE in patients receiving metformin, with a diarrhea predominance, followed by bloating, diarrhea, abdominal pain, constipation, and vomiting. The incidence is lower in patients administered with XR metformin.

TRIAL REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021289975 , identifier CRD42021289975.

Advances in the Insulin-Heart Axis: Current Therapies and Future Directions

The insulin-heart axis plays a pivotal role in the pathophysiology of cardiovascular disease (CVD) in insulin-resistant states, including type 2 diabetes mellitus. Insulin resistance disrupts glucose and lipid metabolism, leading to systemic inflammation, oxidative stress, and atherogenesis, which contribute to heart failure (HF) and other CVDs. This review was conducted by systematically searching PubMed, Scopus, and Web of Science databases for peer-reviewed studies published in the past decade, focusing on therapeutic interventions targeting the insulin-heart axis. Studies were selected based on their relevance to insulin resistance, cardiovascular outcomes, and the efficacy of pharmacologic treatments. Key findings from the review highlight the efficacy of lifestyle modifications, such as dietary changes and physical activity, which remain the cornerstone of managing insulin resistance and improving cardiovascular outcomes. Moreover, pharmacologic interventions, such as metformin, sodium-glucose cotransporter 2 inhibitors, glucagon-like peptide-1 receptor agonists, and dipeptidyl peptidase-4 inhibitors, have shown efficacy in reducing cardiovascular risk by addressing metabolic dysfunction, reducing inflammation, and improving endothelial function. Furthermore, emerging treatments, such as angiotensin receptor-neprilysin inhibitors, and mechanical interventions like ventricular assist devices offer new avenues for managing HF in insulin-resistant patients. The potential of these therapies to improve left ventricular ejection fraction and reverse pathological cardiac remodeling highlights the importance of early intervention. However, challenges remain in optimizing treatment regimens and understanding the long-term cardiovascular effects of these agents. Future research should focus on personalized approaches that integrate lifestyle and pharmacologic therapies to effectively target the insulin-heart axis and mitigate the burden of cardiovascular complications in insulin-resistant populations.

Extended-release metformin in patients with prediabetes, chro­nic heart failure and abdominal obesity in light of the effect on fat depot compartments and glucose metabolism parameters

BACKGROUND: Considering the role of visceral adipose tissue deposition in the pathogenesis of heart failure with preserved ejection fraction (HFpEF) and the positive effect of metformin on weight loss, the effect of this drug on adipose tissue compartments in patients with HFpEF is interest.

AIM: To study the effect of extended-release metformin (XR) on various fat depots and parameters of insulin-glucose homeostasis in patients with HFpEF, prediabetes and abdominal obesity (AO).

MATERIALS AND METHODS: Study design: single-center, open-ended, randomized, prospective, controlled. The registration numbers of the study in the NARNIS register RNI.25.004. The study included 64 people (50% men, median age 58 [55.25; 59.75] years) with HFpEF, prediabetes and AO. All patients (groups A and B) received optimal HFpEF therapy. In group A (n=32), metformin XR 1000–1500 mg/day was additionally prescribed. All patients underwent general clinical examination, calculation of insulin resistance indices, ultrasound lipometry to determine the thickness of epicardial, preperitoneal and subcutaneous fat initially and after 6 months.

RESULTS: In group A patients, there was a decrease in waist circumference by 0.9% (p=0.002), hip circumference by 1.25% (p=0.001), body weight by 4.7% (p<0.0001), body mass index by 1.8% (p=0.001) compared with baseline. In the control group, the anthropometric parameters of the dynamics did not change. Also, in the metformin XR group, glucose levels decreased by 4.6% (p=0.009), glycated hemoglobin by 3.3% (p=0.047), insulin by 12.5% (p=0.024) and insulin resistance indices: HOMA-IR by 19.8% (p=0.009), FIRI by 19.8% (p=0.009). In contrast, patients from group B had an increase in fasting plasma insulin levels by 33.6% (p=0.035), with an increase in HOMA-IR indices by 27.4% (p=0.026) and FIRI by 26.9% (p=0.025). The dynamics of ultrasound lipometry parameters was observed only in group A: the thickness of the preperitoneal fat decreased by 14.5% (p<0.0001), the thickness of the subcutaneous fat decreased by 12.3% (p<0.0001).

CONCLUSION: In patients with prediabetes, HFpEF and AO, taking metformin XR 1000-1500 mg/day for 6 months against the background of optimal basic HFpEF therapy was associated with a decrease in subcutaneous and preperitoneal fat, also had a beneficial effect on glucose metabolism parameters compared with the control group.

Pharmacological characterization of the antidiabetic drug metformin in atherosclerosis inhibition: A comprehensive insight

BACKGROUND

Atherosclerosis (AS) is a progressive disease that interferes with blood flow, leading to cardiovascular complications such as hypertension, ischemic heart disease, ischemic stroke, and vascular ischemia. The progression of AS is correlated with inflammation, oxidative stress, and endothelial dysfunction. Various signaling pathways, like nuclear erythroid-related factor 2 (Nrf2) and Kruppel-like factor 2 (KLF2), are involved in the pathogenesis of AS. Nrf2 and KLF2 have anti-inflammatory and antioxidant properties. Thus, activation of these pathways may reduce the development of AS. Metformin, an insulin-sensitizing drug used in the management of type 2 diabetes mellitus (T2DM), increases the expression of Nrf2 and KLF2. AS is a common long-term macrovascular complication of T2DM. Thus, metformin, through its pleiotropic anti-inflammatory effect, may attenuate the development and progression of AS.

AIMS

Therefore, this review aims to investigate the possible role of metformin in AS concerning its effect on Nrf2 and KLF2 and inhibition of reactive oxygen species (ROS) formation. In addition to its antidiabetic effect, metformin can reduce cardiovascular morbidities and mortalities compared to other antidiabetic agents, even with similar blood glucose control by the Nrf2/KLF2 pathway activation.

CONCLUSION

In conclusion, metformin is an effective therapeutic strategy against the development and progression of AS, mainly through activation of the KLF2/Nrf2 axis.

Metformin synergizes with PD-1 blockade to promote normalization of tumor vessels via CD8T cells and IFNγ

Tumor blood vessels are highly leaky in structure and have poor blood perfusion, which hampers infiltration and function of CD8T cells within tumor. Normalizing tumor vessels is thus thought to be important in promoting the flux of immune T cells and enhancing ant-tumor immunity. However, how tumor vasculature is normalized is poorly understood. Metformin (Met) combined with ant-PD-1 therapy is known to stimulate proliferation of and to produce large amounts of IFNγ from tumor-infiltrating CD8T lymphocytes (CD8TILs). We found that the combination therapy promotes the pericyte coverage of tumor vascular endothelial cells (ECs) to improve blood perfusion and that it suppresses the hyperpermeability through the increase of VE-cadherin. Peripheral node addressin(PNAd) and vascular cell adhesion molecule (VCAM)-1, both implicated to promote tumor infiltration of CD8T cells, were also increased. Importantly, tumor vessel normalization, characterized as the reduced 70-kDa dextran leakage and the enhancement of VE-cadherin and VCAM-1, were canceled by anti-CD8 Ab or anti-IFNγ Ab injection to mice. The increased CD8TILs were also abrogated by anti-IFNγ Ab injection. In vascular ECs, flow cytometry analysis revealed that pSTAT1 expression was found to be associated with VE-cadherin expression. Moreover, in vitro treatment with Met and IFNγ enhanced VE-cadherin and VCAM-1 on human umbilical vein endothelial cells (HUVECs). The Kaplan-Meier method revealed a correlation of VE-cadherin or VCAM-1 levels with overall survival in patients treated with immune checkpoint inhibitors. These data indicate that IFNγ-mediated cross talk of CD8TILs with tumor vessels is important for creating a better tumor microenvironment and maintaining sustained antitumor immunity.

Bone effects of metformin monotherapy and its combination with teneligliptin: A 12-week follow-up study in patients with type 2 diabetes mellitus

AIMS

The skeletal effects of metformin monotherapy and in combination with teneligliptin are not well illustrated in patients with T2DM. To address this, we conducted an observational study to evaluate the effect of these oral hypoglycemic agents on bone turnover markers.

METHODS

We recruited patients with T2DM and first-ever prescribed metformin monotherapy or metformin combined with teneligliptin from a tertiary care teaching hospital in New Delhi, North India. Both bone formation and resorption markers, IL-6 and PTD, were estimated along with glycated hemoglobin at baseline and 12 weeks.

RESULTS

In both groups, hbA1c levels decreased significantly from baseline to 12 weeks. In the metformin-treated group, β-CTX, sRANKL, IL-6, and PTD decreased significantly, and no significant changes were observed in P1NP, OC, BAP, or OPG at 12 weeks from baseline. In the metformin + teneligliptin group, BAP, β-CTX, sRANKL, IL-6, and PTD decreased significantly, and no significant changes were observed in P1NP, OC, or OPG after 12 weeks from baseline.

CONCLUSIONS

The positive bone outcome of metformin or teneligliptin was linked to bone resorption rather than bone formation and was independent of changes in HbA1c or PTD. However, these results must be confirmed with well-designed RCTs with more extended follow-up periods.

Repurposing Metformin for the Treatment of Atrial Fibrillation: Current Insights

Metformin is an orally effective anti-hyperglycemic drug that despite being introduced over 60 years ago is still utilized by an estimated 120 to 150 million people worldwide for the treatment of type 2 diabetes (T2D). Metformin is used off-label for the treatment of polycystic ovary syndrome (PCOS) and for pre-diabetes and weight loss. Metformin is a safe, inexpensive drug with side effects mostly limited to gastrointestinal issues. Prospective clinical data from the United Kingdom Prospective Diabetes Study (UKPDS), completed in 1998, demonstrated that metformin not only has excellent therapeutic efficacy as an anti-diabetes drug but also that good glycemic control reduced the risk of micro- and macro-vascular complications, especially in obese patients and thereby reduced the risk of diabetes-associated cardiovascular disease (CVD). Based on a long history of clinical use and an excellent safety record metformin has been investigated to be repurposed for numerous other diseases including as an anti-aging agent, Alzheimer's disease and other dementias, cancer, COVID-19 and also atrial fibrillation (AF). AF is the most frequently diagnosed cardiac arrythmia and its prevalence is increasing globally as the population ages. The argument for repurposing metformin for AF is based on a combination of retrospective clinical data and in vivo and in vitro pre-clinical laboratory studies. In this review, we critically evaluate the evidence that metformin has cardioprotective actions and assess whether the clinical and pre-clinical evidence support the use of metformin to reduce the risk and treat AF.

Insulin resistance before type 2 diabetes onset is associated with increased risk of albuminuria after diabetes onset: A prospective cohort study

AIM

Reduced renal insulin signalling is implicated in the pathogenesis of albuminuria. We sought to investigate whether insulin action and secretion, measured before diabetes onset, are associated with the development of albuminuria after diabetes onset.

MATERIALS AND METHODS

Baseline body composition, insulin sensitivity by hyperinsulinaemic-euglycaemic clamp at submaximal and maximal insulin stimulation (240 and 2400 pmol/m2/min; M-low and M-high), and insulin secretion by intravenous glucose tolerance test [acute insulin response (AIR)] were measured in 170 Southwestern Indigenous American adults who subsequently developed diabetes. After diabetes onset and during the median follow-up of 13.6 years, 81 participants (48%) developed albuminuria (urine albumin-to-creatinine ratio ≥30 mg/g). Separate associations of M-low, M-high and AIR (per 1-SD change) with the risk of albuminuria were assessed by Cox regression models adjusted for age, sex and body fat (%).

RESULTS

Participants who developed albuminuria were of similar age (26.4 ± 5.4 vs. 27.5 ± 6.1 years), sex (46% vs. 48% male), body fat (36.4 ± 7.5 vs. 35.7 ± 7.9%) and AIR [2.3 ± 0.3 vs. 2.3 ± 0.3, pmol/L (log)] as those who did not develop albuminuria but had lower insulin sensitivity [M-low: 0.33 ± 0.08 vs. 0.36 ± 0.12, p = .03; M-high: 0.87 ± 0.11 vs. 0.91 ± 0.12, p = .02; mg/kg-metabolic body size/min (log)]. In separate adjusted models, lower M-low and M-high were both associated with an increased risk for albuminuria [hazard ratio (HR) 1.51, 95% confidence interval (CI) 1.14, 2.00, p = .004; HR 1.31, 95% CI 1.06, 1.63, p = .01), whereas AIR was not (HR 1.15, 95% CI 0.87, 1.56, p = .3).

CONCLUSIONS

Lower insulin sensitivity is associated with the development of albuminuria, suggesting a role for insulin signalling in the pathogenesis of proteinuria.

Sodium-Glucose Cotransporter 2 Inhibitors Reduce the Risk of Hospitalization for Heart Failure and Amputation Rate Compared With Incretin-Based Therapy in Patients With Diabetic Foot Disease: A Nationwide Population-Based Study

OBJECTIVE

Major adverse cardiovascular event (MACE) outcomes associated with sodium-glucose cotransporter 2 inhibitor (SGLT2i) and glucagon-like peptide-1 receptor agonist (GLP-1 RA) therapies remain unclear in patients with type 2 diabetes and newly diagnosed diabetic foot complications (DFCs). This study examined the impact of SGLT2i and GLP-1 RA use on the rates of MACEs and amputations in patients with type 2 diabetes and without cardiovascular disease.

METHODS

Data from the Taiwan National Health Insurance Research Database (2004-2017) were analyzed, focusing on patients with type 2 diabetes without previous MACE and newly diagnosed DFCs. The primary outcome was the first MACE occurrence, and the secondary outcomes included MACE components, all-cause mortality, and lower extremity amputation (LEA) rates.

RESULTS

SGLT2i users showed a significant decrease in the MACE (hazard ratio [HR], 0.64; 95% confidence interval [CI], 0.46-0.88) and hospitalization for heart failure (HR, 0.54; 95% CI, 0.35-0.83) rates compared with dipeptidyl peptidase-4 inhibitor users. The amputation rates were also lower in SGLT2i users without LEA at the first DFC diagnosis (HR, 0.28; 95% CI, 0.10-0.75) and did not increase in those with a history of peripheral artery disease or LEA. No significant differences were observed between dipeptidyl peptidase-4 inhibitor and GLP-1 RA users in terms of the primary or secondary outcomes.

CONCLUSION

In patients with type 2 diabetes initially diagnosed with DFC, SGLT2i are effective in significantly reducing the hospitalization for heart failure and MACE rates. SGLT2i lower the amputation rates, especially in patients who have not previously had a LEA, than the dipeptidyl peptidase-4 inhibitor therapy.

View on Metformin: Antidiabetic and Pleiotropic Effects, Pharmacokinetics, Side Effects, and Sex-Related Differences

Metformin is a synthetic biguanide used as an antidiabetic drug in type 2 diabetes mellitus, achieved by studying the bioactive metabolites of Galega officinalis L. It is also used off-label for various other diseases, such as subclinical diabetes, obesity, polycystic ovary syndrome, etc. In addition, metformin is proposed as an add-on therapy for several conditions, including autoimmune diseases, neurodegenerative diseases, and cancer. Although metformin has been used for many decades, it is still the subject of many pharmacodynamic and pharmacokinetic studies in light of its extensive use. Metformin acts at the mitochondrial level by inhibiting the respiratory chain, thus increasing the AMP/ATP ratio and, subsequently, activating the AMP-activated protein kinase. However, several other mechanisms have been proposed, including binding to presenilin enhancer 2, increasing GLP1 release, and modification of microRNA expression. Regarding its pharmacokinetics, after oral administration, metformin is absorbed, distributed, and eliminated, mainly through the renal route, using transporters for cationic solutes, since it exists as an ionic molecule at physiological pH. In this review, particular consideration has been paid to literature data from the last 10 years, deepening the study of clinical trials inherent to new uses of metformin, the differences in effectiveness and safety observed between the sexes, and the unwanted side effects. For this last objective, metformin safety was also evaluated using both VigiBase and EudraVigilance, respectively, the WHO and European databases of the reported adverse drug reactions, to assess the extent of metformin side effects in real-life use.

Effectiveness of metformin for the reversal of cold-ischemia-induced damage in hepatosteatosis

BACKGROUND

Primary dysfunction and rejection are more common in donor liver tissues with steatosis. AMP-activated protein kinase (AMPK) assumes organ-protective functions during ischemia. Metformin was used for the activation of AMPK in hepatocytes. The aim of this study is to investigate the effectiveness of metformin administration for the reversal of cold-ischemia-induced damage in hepatosteatosis.

MATERIAL AND METHODS

Seven-week-old C7BL56 male-mice (n = 109) were separated into four groups depending on diet type and metformin use. A specific diet model was followed for 10 weeks to induce hepatosteatosis. A group of the animals was administered with metformin for the last four weeks via oral gavage. After resection, the liver tissues were perfused and kept for 0-6-12-24 h in the UW solution. Histopathological examinations were performed, and Western blot was utilized to analyze p-AMPK and AMPK expression levels.

RESULTS

Hepatosteatosis decreased significantly with metformin. The steatotic liver group had more prominent pericentral inflammation, necrosis as well as showing a decreased and more delayed AMPK response than the non-fat group. All these alterations could be corrected using metformin.

CONCLUSION

Metformin can increase the resistance of livers with hepatosteatosis to cold-ischemia-induced damage, which in turn may pave the way for successful transplantation of fatty living-donor livers.

Examining the clinical relevance of metformin as an antioxidant intervention

In physiological concentrations, reactive oxygen species play a vital role in regulating cell signaling and gene expression. Nevertheless, oxidative stress is implicated in the pathogenesis of numerous diseases and can inflict damage on diverse cell types and tissues. Thus, understanding the factors that mitigate the deleterious effects of oxidative stress is imperative for identifying new therapeutic targets. In light of the absence of direct treatment recommendations for reducing oxidative stress, there is a continuing need for fundamental research that utilizes innovative therapeutic approaches. Metformin, known for its multifaceted beneficial properties, is acknowledged for its ability to counteract the adverse effects of increased oxidative stress at both molecular and cellular levels. In this review, we delve into recent insights regarding metformin's antioxidant attributes, aiming to expand its clinical applicability. Our review proposes that metformin holds promise as a potential adjunctive therapy for various diseases, given its modulation of oxidative stress characteristics and regulation of diverse metabolic pathways. These pathways include lipid metabolism, hormone synthesis, and immunological responses, all of which may experience dysregulation in disease states, contributing to increased oxidative stress. Furthermore, our review introduces potential novel metformin-based interventions that may merit consideration in future research. Nevertheless, the necessity for clinical trials involving this drug remains imperative, as they are essential for establishing therapeutic dosages and addressing challenges associated with dose-dependent effects.

Upregulation of Anti-Angiogenic miR-106b-3p Correlates Negatively with IGF-1 and Vascular Health Parameters in a Model of Subclinical Cardiovascular Disease: Study with Metformin Therapy

Well-controlled type 1 diabetes mellitus (T1DM) is regarded as a model of subclinical cardiovascular disease (CVD), characterized by inflammation and adverse vascular health. However, the underlying mechanisms are not fully understood. We investigated insulin-like growth factor-1 (IGF-1) and IGF-binding protein-3 (IGFBP-3) levels, their correlation to miR-106b-3p expression in a subclinical CVD model, and the cardioprotective effect of metformin. A total of 20 controls and 29 well-controlled T1DM subjects were studied. Plasma IGF-1, IGFBP-3 levels, and miR-106b-3p expression in colony-forming unit-Hills were analyzed and compared with vascular markers. miR-106b-3p was upregulated in T1DM (p < 0.05) and negatively correlated with pro-angiogenic markers CD34+/100-lymphocytes (p < 0.05) and IGF-1 (p < 0.05). IGF-1 was downregulated in T1DM (p < 0.01), which was associated with increased inflammatory markers TNF-α, CRP, and IL-10 and reduced CD34+/100-lymphocytes. IGFBP-3 had no significant results. Metformin had no effect on IGF-1 but significantly reduced miR-106b-3p (p < 0.0001). An Ingenuity Pathway analysis predicted miR-106b-3p to inhibit PDGFA, PIK3CG, GDNF, and ADAMTS13, which activated CVD. Metformin was predicted to be cardioprotective by inhibiting miR-106b-3p. In conclusion: Subclinical CVD is characterized by a cardio-adverse profile of low IGF-1 and upregulated miR-106b-3p. We demonstrated that the cardioprotective effect of metformin may be via downregulation of upregulated miR-106b-3p and its effect on downstream targets.

Metformin alleviates bevacizumab-induced vascular endothelial injury in mice through growth differentiation factor 15 upregulation

Objectives

Bevacizumab is a commonly used anticancer drug in clinical practice, but it often leads to adverse reactions such as vascular endothelial damage, hypertension, arterial and venous thrombosis, and bleeding. This study investigated the protective effects of metformin against bevacizumab-induced vascular injury in a mouse model and examined the possible involvement of GDF15/PI3K/AKT/FOXO/PPARγ signaling in the effects.

Materials and Methods

C57 male mice were purchased. To investigate metformin, the mice were assigned to the saline, bevacizumab (15 mg every 3 days), metformin (1200 mg/day), and bevacizumab+metformin groups. To investigate GDF15, the mice were assigned to the siNC+bevacizumab, siNC+bevacizumab+metformin, siGDF15+bevacizumab, and siGDF15+bevacizumab+metformin groups. Histological staining was used to evaluate vascular injury. Flow cytometry was used to evaluate apoptosis. ELISA was used to measure plasma endothelial injury markers and proinflammatory cytokines. qRT-PCR and western blot were used to determine the expression of GDF15 and PI3K/AKT/FOXO/PPARγ in aortic tissues.

Results

Metformin alleviated bevacizumab-induced abdominal aortic injury, endothelial cell apoptosis, and systemic inflammation in mice (all P<0.05). Metformin up-regulated GDF15 expression and PI3K/AKT/FOXO/PPARγ signaling in the abdominal aorta of mice treated with bevacizumab (all P<0.05). siGDF15 abolished the vascular protective and anti-inflammatory effects of metformin (all P<0.05). siGDF15 suppressed PI3K/AKT/FOXO/PPARγ signaling in the abdominal aorta of mice treated with bevacizumab (all P<0.05).

Conclusion

Metformin attenuates bevacizumab-induced vascular endothelial injury, apoptosis, and systemic inflammation by activating GDF15/PI3K/AKT/FOXO/PPARγ signaling.

Polycystic Ovary Syndrome and Oxidative Stress-From Bench to Bedside

Oxidative stress (OS) is a condition that occurs as a result of an imbalance between the production of reactive oxygen species (ROS) and the body's ability to detoxify and neutralize them. It can play a role in a variety of reproductive system conditions, including polycystic ovary syndrome (PCOS), endometriosis, preeclampsia, and infertility. In this review, we briefly discuss the links between oxidative stress and PCOS. Mitochondrial mutations may lead to impaired oxidative phosphorylation (OXPHOS), decreased adenosine triphosphate (ATP) production, and an increased production of ROS. These functional consequences may contribute to the metabolic and hormonal dysregulation observed in PCOS. Studies have shown that OS negatively affects ovarian follicles and disrupts normal follicular development and maturation. Excessive ROS may damage oocytes and granulosa cells within the follicles, impairing their quality and compromising fertility. Impaired OXPHOS and mitochondrial dysfunction may contribute to insulin resistance (IR) by disrupting insulin signaling pathways and impairing glucose metabolism. Due to dysfunctional OXPHOS, reduced ATP production, may hinder insulin-stimulated glucose uptake, leading to IR. Hyperandrogenism promotes inflammation and IR, both of which can increase the production of ROS and lead to OS. A detrimental feedback loop ensues as IR escalates, causing elevated insulin levels that exacerbate OS. Exploring the relations between OS and PCOS is crucial to fully understand the role of OS in the pathophysiology of PCOS and to develop effective treatment strategies to improve the quality of life of women affected by this condition. The role of antioxidants as potential therapies is also discussed.

Metformin increases the expression of proinflammatory cytokines and inhibits supraspinatus fatty infiltration

BACKGROUND

After a rotator cuff (RC) tendon tear, the supraspinatus (SS) inflammatory response induces fatty infiltration (FI). Metformin has the effect of regulating the initial inflammatory response of atrophic muscles. Therefore, this study aimed to investigate the effect of metformin use on modulating the expression of proinflammatory cytokines and SS FI in an acute RC tear rat model.

METHODS

This study used 26 male Sprague-Dawley rats. Animals were randomly divided into two groups: The metformin group received metformin for 5 days after cutting the RC tendon, and the control group was administered only with saline after cutting the tendon. Metformin 50 mg/kg was intraperitoneally injected for 5 days. Three rats in each group were sacrificed 5 days after SS tendon rupture surgery, and 10 rats in each group were sacrificed 14 days after surgery. The SS was sampled 5 days after SS tendon tear surgery, and the expression of proinflammatory cytokines was measured by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). On day 14 after sampling, histological analysis of the SS was performed using hematoxylin and eosin, Masson's trichrome, and picrosirius red staining.

RESULTS

On day 5 of surgery, the expression values of interferon gamma (increased 7.2-fold, P < .01), tumor necrosis factor alpha (increased 13-fold, P < .05), interleukin-1β (increased 4.7-fold, P < .001), and interleukin-6 (increased 4.6-fold, P < .01) increased significantly in the metformin group compared with those in the control group. As a result of Oil Red O staining, SS FI was significantly suppressed in the metformin group compared with that in the control group (metformin group, 305 ± 50.3 µm2, P < .001; control group, 3136 ± 662.8 µm2, P < .001). In addition, the SS volume of the metformin group was not reduced compared with those of the control group, and the morphology and structure of the SS were better preserved.

CONCLUSIONS

The results of this study revealed that metformin can increase the expression of proinflammatory cytokines and suppress SS fat infiltration in delayed sutures.

Protein kinase C: A potential therapeutic target for endothelial dysfunction in diabetes

Protein kinase C (PKC) is a family of serine/threonine protein kinases that play an important role in many organs and systems and whose activation contributes significantly to endothelial dysfunction in diabetes. The increase in diacylglycerol (DAG) under high glucose conditions mediates PKC activation and synthesis, which stimulates oxidative stress and inflammation, resulting in impaired endothelial cell function. This article reviews the contribution of PKC to the development of diabetes-related endothelial dysfunction and summarizes the drugs that inhibit PKC activation, with the aim of exploring therapeutic modalities that may alleviate endothelial dysfunction in diabetic patients.

Metformin: A Review of Potential Mechanism and Therapeutic Utility Beyond Diabetes

Metformin has been designated as one of the most crucial first-line therapeutic agents in the management of type 2 diabetes mellitus. Primarily being an antihyperglycemic agent, metformin also has a plethora of pleiotropic effects on various systems and processes. It acts majorly by activating AMPK (Adenosine Monophosphate-Activated Protein Kinase) in the cells and reducing glucose output from the liver. It also decreases advanced glycation end products and reactive oxygen species production in the endothelium apart from regulating the glucose and lipid metabolism in the cardiomyocytes, hence minimizing the cardiovascular risks. Its anticancer, antiproliferative and apoptosis-inducing effects on malignant cells might prove instrumental in the malignancy of organs like the breast, kidney, brain, ovary, lung, and endometrium. Preclinical studies have also shown some evidence of metformin's neuroprotective role in Parkinson's disease, Alzheimer's disease, multiple sclerosis and Huntington's disease. Metformin exerts its pleiotropic effects through varied pathways of intracellular signalling and exact mechanism in the majority of them remains yet to be clearly defined. This article has extensively reviewed the therapeutic benefits of metformin and the details of its mechanism for a molecule of boon in various conditions like diabetes, prediabetes, obesity, polycystic ovarian disease, metabolic derangement in HIV, various cancers and aging.

Serum Concentrations and Dietary Intake of Vitamin B12 in Children and Adolescents on Metformin: A Case-Control Study

The International Society of Pediatric and Adolescent Diabetes (ISPAD) recommends metformin (MET) use for metabolic disturbances and hyperglycemia, either in combination with insulin therapy or alone. A caveat of MET therapy has been suggested to be biochemical vitamin B₁₂ deficiency, as seen mainly in studies conducted in adults. In the present case-control study, children and adolescents of different weight status tiers on MET therapy for a median of 17 months formed the cases group (n = 23) and were compared with their peers not taking MET (n = 46). Anthropometry, dietary intake, and blood assays were recorded for both groups. MET group members were older, heavier, and taller compared with the controls, although BMI z-scores did not differ. In parallel, blood phosphorus and alkaline phosphatase (ALP) concentrations were lower in the MET group, whereas MCV, Δ₄-androstenedione, and DHEA-S were higher. No differences were observed in the HOMA-IR, SHBG, hemoglobin, HbA1c, vitamin B₁₂, or serum 25(OH)D₃ concentrations between groups. Among those on MET, 17.4% exhibited vitamin B₁₂ deficiency, whereas none of the controls had low vitamin B₁₂ concentrations. Participants on MET therapy consumed less energy concerning their requirements, less vitamin B₁₂, more carbohydrates (as a percentage of the energy intake), and fewer fats (including saturated and trans fats) compared with their peers not on MET. None of the children received oral nutrient supplements with vitamin B₁₂. The results suggest that, in children and adolescents on MET therapy, the dietary intake of vitamin B₁₂ is suboptimal, with the median coverage reaching 54% of the age- and sex-specific recommended daily allowance. This low dietary intake, paired with MET, may act synergistically in reducing the circulating vitamin B₁₂ concentrations. Thus, caution is required when prescribing MET in children and adolescents, and replacement is warranted.

A Glimpse into Milestones of Insulin Resistance and an Updated Review of Its Management

Insulin is the main metabolic regulator of fuel molecules in the diet, such as carbohydrates, lipids, and proteins. It does so by facilitating glucose influx from the circulation into the liver, adipose tissue, and skeletal myocytes. The outcome of which is subjected to glycogenesis in skeletal muscle and lipogenesis in adipose tissue, as well as in the liver. Therefore, insulin has an anabolic action while, on the contrary, hypoinsulinemia promotes the reverse process. Protein breakdown in myocytes is also encountered during the late stages of diabetes mellitus. The balance of the blood glucose level in physiological conditions is maintained by virtue of the interactive functions of insulin and glucagon. In insulin resistance (IR), the balance is disturbed because glucose transporters (GLUTs) of cell membranes fail to respond to this peptide hormone, meaning that glucose molecules cannot be internalized into the cells, the consequence of which is hyperglycemia. To develop the full state of diabetes mellitus, IR should be associated with the impairment of insulin release from beta-cells of the pancreas. Periodic screening of individuals of high risk, such as those with obesity, hypercholesterolemia, and pregnant nulliparous women in antenatal control, is vital, as these are important checkpoints to detect cases of insulin resistance. This is pivotal as IR can be reversed, provided it is detected in its early stages, through healthy dietary habits, regular exercise, and the use of hypoglycemic agents. In this review, we discuss the pathophysiology, etiology, diagnosis, preventive methods, and management of IR in brief.

Overcoming chemoresistance in non-angiogenic colorectal cancer by metformin via inhibiting endothelial apoptosis and vascular immaturity

The development of chemoresistance which results in a poor prognosis often renders current treatments for colorectal cancer (CRC). In this study, we identified reduced microvessel density (MVD) and vascular immaturity resulting from endothelial apoptosis as therapeutic targets for overcoming chemoresistance. We focused on the effect of metformin on MVD, vascular maturity, and endothelial apoptosis of CRCs with a non-angiogenic phenotype, and further investigated its effect in overcoming chemoresistance. In situ transplanted cancer models were established to compare MVD, endothelial apoptosis and vascular maturity, and function in tumors from metformin- and vehicle-treated mice. An in vitro co-culture system was used to observe the effects of metformin on tumor cell-induced endothelial apoptosis. Transcriptome sequencing was performed for genetic screening. Non-angiogenic CRC developed independently of angiogenesis and was characterized by vascular leakage, immaturity, reduced MVD, and non-hypoxia. This phenomenon had also been observed in human CRC. Furthermore, non-angiogenic CRCs showed a worse response to chemotherapeutic drugs in vivo than in vitro. By suppressing endothelial apoptosis, metformin sensitized non-angiogenic CRCs to chemo-drugs via elevation of MVD and improvement of vascular maturity. Further results showed that endothelial apoptosis was induced by tumor cells via activation of caspase signaling, which was abrogated by metformin administration. These findings provide pre-clinical evidence for the involvement of endothelial apoptosis and subsequent vascular immaturity in the chemoresistance of non-angiogenic CRC. By suppressing endothelial apoptosis, metformin restores vascular maturity and function and sensitizes CRC to chemotherapeutic drugs via a vascular mechanism.

Eid R, Alqahtani SM, Abd Ellatif M, Al-Ani B, Albawardi A. Lower Extremity Arterial Disease in Type 2 Diabetes Mellitus: Metformin Inhibits Femoral Artery Ultrastructural Alterations as well as Vascular Tissue Levels of AGEs/ET-1 Axis-Mediated Inflammation and Modulation of Vascular iNOS and eNOS Expression

Lower extremity arterial disease (LEAD) is a major risk factor for amputation in diabetic patients. The advanced glycation end products (AGEs)/endothelin-1 (ET-1)/nitric oxide synthase (NOS) axis-mediated femoral artery injury with and without metformin has not been previously investigated. Type 2 diabetes mellitus (T2DM) was established in rats, with another group of rats treated for two weeks with 200 mg/kg metformin, before being induced with T2DM. The latter cohort were continued on metformin until they were sacrificed at week 12. Femoral artery injury was established in the diabetic group as demonstrated by substantial alterations to the femoral artery ultrastructure, which importantly were ameliorated by metformin. In addition, diabetes caused a significant (p < 0.0001) upregulation of vascular tissue levels of AGEs, ET-1, and iNOS, as well as high blood levels of glycated haemoglobin, TNF-α, and dyslipidemia. All of these parameters were also significantly inhibited by metformin. Moreover, metformin treatment augmented arterial eNOS expression which had been inhibited by diabetes progression. Furthermore, a significant correlation was observed between femoral artery endothelial tissue damage and glycemia, AGEs, ET-1, TNF-α, and dyslipidemia. Thus, in a rat model of T2DM-induced LEAD, an association between femoral artery tissue damage and the AGEs/ET-1/inflammation/NOS/dyslipidemia axis was demonstrated, with metformin treatment demonstrating beneficial vascular protective effects.

Effects of a Combination of Empagliflozin Plus Metformin vs. Metformin Monotherapy on NAFLD Progression in Type 2 Diabetes: The IMAGIN Pilot Study

Non-alcoholic fatty liver disease (NAFLD) comprises a heterogeneous group of metabolic liver diseases and is characterized by the presence of steatosis in at least 5% of hepatocytes. The aim of our study was to assess the effect of the combination therapy of empagliflozin + metformin vs. metformin monotherapy on NAFLD progression in type 2 diabetic (T2DM) patients. Sixty-three metformin-treated T2DM patients who were SGLT2i-naïve and had an ultrasound diagnosis of NAFLD (aged 60.95 ± 11.14 years; males, 57.1%) were included in the present analysis. Thirty-three started the combination therapy. All patients were observed for 6 months and routinely monitored with anthropometry, blood biochemistry, and FibroScan^®/CAP. At the 6-month follow-up, the combination therapy group presented a significant reduction in BMI (30.83 ± 3.5 vs. 28.48 ± 3.25), glycated hemoglobin (8.2 (7.4-8.8)) vs. 7.2 (6.8-7.9), ALT (68.5 (41.5-88.0) vs. 45.00 (38.00, 48.00)), CAP parameter (293.5 (270.0-319.25) vs. 267.00 (259.50, 283.75)) and steatosis degree (p = 0.001) in comparison with the control group, whose parameters remained almost stable over time. In patients affected by T2DM, the combination of empagliflozin + metformin vs. metformin monotherapy ameliorated liver steatosis, ALT levels, body weight, and glycated hemoglobin after a 6-month follow-up.

Effects of Endocrine Metabolic Factors on Hemocyte Parameters, Tumor Markers, and Blood Electrolytes in Patients with Hyperglycemia

Objective

This study was designed to investigate the effect of endocrine metabolic factors on hemocyte parameters, tumor markers, and blood electrolytes in patients with hyperglycemia.

Methods

In this study, 1791 patients with hyperglycemia were recruited and grouped according to different testing indexes, and their medical records and laboratory indexes were recorded and analyzed.

Results

In adult patients with hyperglycemia, we found that high-density lipoprotein cholesterol (HDL-C) was negatively correlated with white blood cell (WBC) and could exert an effect on WBC; triglyceride (TG) level was positively associated with lymphocyte (LYM#); age, TG, and P affected the level of LYM#; and uric acid (UA) level was positively related to eosinophil (EO#). Besides, age was positively correlated with red blood cell distribution width-coefficient of variation (RDW-CV) level; fasting blood glucose (FBG) and serum phosphorus (P) were negatively correlated with RDW-CV level; and age, creatinine (Cre), FBG, HDL-C, and P were influencing factors of RDW-CV level in adult hyperglycemic patients. HDL-C was negatively correlated with fibrinogen (Fib) level, and age, HDL-C, serum kalium (K), serum sodium (Na), and body mass index (BMI) were the influencing factors of Fib levels. TG was positively associated with neuron-specific enolase (NSE) level and affected the NSE level. Serum magnesium (Mg) was negatively related to carcinoembryonic antigen (CEA) level, and sex, age, FBG, Mg, and BMI could have an effect on CEA level. As well, age and FBG were positively associated with carbohydrate antigen 50 (CA50) levels, UA was negatively correlated with CA50 levels, and age, aspartate aminotransferase (AST), UA, and FBG were the influencing factors of CA50 levels. FBG was negatively related to Mg levels; K, serum zinc (Zn), and fasting C-peptide (C-P) were positively correlated with Mg levels; and FBG, K, Zn, and C-P had an effect on Mg levels.

Conclusion

Endocrine metabolic factors are closely related to hemocyte parameters, tumor markers, and blood electrolytes in patients with hyperglycemia.

Role of metformin in inflammation

BACKGROUND

Metformin has good anti-hyperglycemic effectiveness, but does not induce hypoglycemia，is very safe, and has become the preferred drug for the treatment of type 2 diabetes. Recently, the other effects of metformin, such as being anti-inflammatory and delaying aging, have also attracted increased attention.

METHODS AND RESULTS

The relevant literatures on pubmed and other websites for reading, classification and sorting, and did not involve any animal experiments.

CONCLUSION

Metformin has anti-inflammatory effects through multiple routes, which provides potential therapeutic targets for certain inflammatory diseases, such as neuroinflammation and rheumatoid arthritis. In addition, inflammation is a key component of tumor occurrence and development ; thus, targeted inflammatory intervention is a significant benefit for both cancer prevention and treatment. Therefore, metformin may have further potential for inflammation-related disease prevention and treatmen. However, the inflammatory mechanism is complex; various molecules are connected and influence each other. For example, metformin significantly inhibits p65 nuclear translocation, but pretreatment with compound C, an AMPK inhibitor, abolishes this effect, and silencing of HMGB1 inhibits NF-κB activation . SIRT1 deacetylates FoxO, increasing its transcriptional activity . mTOR in dendritic cells regulates FoxO1 via AKT. The interactions among various molecules should be further explored to clarify their specific mechanisms and provide more direction for the treatment of inflammatory diseases, as well as cancer.

Metformin and Its Immune-Mediated Effects in Various Diseases

Metformin has been a long-standing prescribed drug for treatment of type 2 diabetes (T2D) and its beneficial effects on virus infection, autoimmune diseases, aging and cancers are also recognized. Metformin modulates the differentiation and activation of various immune-mediated cells such as CD4+ and CD+8 T cells. The activation of adenosine 5'-monophosphate-activated protein kinase (AMPK) and mammalian target of rapamycin complex 1 (mTORC1) pathway may be involved in this process. Recent studies using Extracellular Flux Analyzer demonstrated that metformin alters the activities of glycolysis, oxidative phosphorylation (OXPHOS), lipid oxidation, and glutaminolysis, which tightly link to the modulation of cytokine production in CD4+ and CD+8 T cells in various disease states, such as virus infection, autoimmune diseases, aging and cancers.

Current Knowledge on the Pathophysiology of Lean/Normal-Weight Type 2 Diabetes

Since early times, being overweight and obesity have been associated with impaired glucose metabolism and type 2 diabetes (T2D). Similarly, a less frequent adult-onset diabetes in low body mass index (BMI) people has been known for many decades. This form is mainly found in developing countries, whereby the largest increase in diabetes incidence is expected in coming years. The number of non-obese patients with T2D is also on the rise among non-white ethnic minorities living in high-income Western countries due to growing migratory flows. A great deal of energy has been spent on understanding the mechanisms that bind obesity to T2D. Conversely, the pathophysiologic features and factors driving the risk of T2D development in non-obese people are still much debated. To reduce the global burden of diabetes, we need to understand why not all obese people develop T2D and not all those with T2D are obese. Moreover, through both an effective prevention and the implementation of an individualized clinical management in all people with diabetes, it is hoped that this will help to reduce this global burden. The purpose of this review is to take stock of current knowledge about the pathophysiology of diabetes not associated to obesity and to highlight which aspects are worthy of future studies.

Gut microbiota is correlated with gastrointestinal adverse events of metformin in patients with type 2 diabetes

Aim

Gastrointestinal discomfort is the most common adverse event in metformin treatment for type 2 diabetes. The mechanism of action of metformin is associated with gut microbiota. However, the gut microbial community structure related to metformin-induced gastrointestinal adverse events remains unclear. This study aimed to investigate it.

Methods

50 patients with newly diagnosed diabetes were treated with metformin 1500mg/d for 12 weeks. The patients were divided into two groups according to whether gastrointestinal adverse events occurred (group B) or did not occur (group A) after treatment. The fecal bacterial communities and short-chain fatty acids (SCFAs) were sequenced and compared. 70 diabetes mice were randomly divided into 8 groups and treated with metformin (Met), clindamycin (Clin) and/or SCFA, which were the Met+/Clin+, Met+/Clin-, Met-/Clin+, Met-/Clin-, Met+/SCFA+, Met+/SCFA-, Met-/SCFA+ and Met-/SCFA- group. After 4 weeks of metformin treatment, blood glucose, food intake, fecal SCFAs, gut microbiota and gut hormones were measured.

Results

Metformin increased the abundance of Phascolarctobacterium, Intestinimonas and Clostridium III. Functional prediction analysis showed that the propanoate metabolism pathway was significantly up-regulated. The concentrations of acetic acid and propanoic acid in feces were significantly increased. The abundance of Clostridium sensu stricto, Streptococcus and Akkermansia induced by metformin in group B was higher than that in group A. The propanoate metabolism pathway and propanoic acid in feces were significantly up-regulated in group B. In the animal experiments, the food intake decreased and glucose control increased in metformin groups compared with those in the control groups. The total GLP-1 level in the Met+/Clin- group was significantly higher than that in the Met-/Clin- group, while there was no statistical difference between the Met-/Clin- and Met+/Clin+ group. The total GLP-1 level in the Met-/SCFA+ group was significantly higher than that in the Met-/SCFA-group, while the levels of total GLP-1 and active GLP-1 in the Met+/SCFA- group and the Met+/SCFA+ group were significantly higher than those in the Met-/SCFA-group.

Conclusions

Our data suggest that metformin promotes the secretion of intestinal hormones such as GLP-1 by increasing the abundance of SCFA-producing bacteria, which not only plays an anti-diabetic role, but also may causes gastrointestinal adverse events.

Glycated Haemoglobin A1c Variability Score Elicits Kidney Function Decline in Chinese People Living with Type 2 Diabetes

Our aim was to investigate the association of glycated haemoglobin A1c (HbA1c) variability score (HVS) with estimated glomerular filtration rate (eGFR) slope in Chinese adults living with type 2 diabetes. This cohort study included adults with type 2 diabetes attending outpatient clinics between 2011 and 2019 from a large electronic medical record-based database of diabetes in China (WECODe). We estimated the individual-level visit-to-visit HbA1c variability using HVS, a proportion of changes in HbA1c of ≥0.5% (5.5 mmol/mol). We estimated the odds of people experiencing a rapid eGFR annual decline using a logistic regression and differences across HVS categories in the mean eGFR slope using a mixed-effect model. The analysis involved 2397 individuals and a median follow-up of 4.7 years. Compared with people with HVS ≤ 20%, those with HVS of 60% to 80% had 11% higher odds of experiencing rapid eGFR annual decline, with an extra eGFR decline of 0.93 mL/min/1.73 m2 per year on average; those with HVS > 80% showed 26% higher odds of experiencing a rapid eGFR annual decline, with an extra decline of 1.83 mL/min/1.73 m2 per year on average. Chinese adults with type 2 diabetes and HVS > 60% could experience a more rapid eGFR decline.

Endothelium-Derived Relaxing Factors and Endothelial Function: A Systematic Review

BACKGROUND

The endothelium plays a pivotal role in homeostatic mechanisms. It specifically modulates vascular tone by releasing vasodilatory mediators, which act on the vascular smooth muscle. Large amounts of work have been dedicated towards identifying mediators of vasodilation and vasoconstriction alongside the deleterious effects of reactive oxygen species on the endothelium. We conducted a systematic review to study the role of the factors released by the endothelium and the effects on the vessels alongside its role in atherosclerosis.

METHODS

A search was conducted with appropriate search terms. Specific attention was offered to the effects of emerging modulators of endothelial functions focusing the analysis on studies that investigated the role of reactive oxygen species (ROS), perivascular adipose tissue, shear stress, AMP-activated protein kinase, potassium channels, bone morphogenic protein 4, and P2Y2 receptor.

RESULTS

530 citations were reviewed, with 35 studies included in the final systematic review. The endpoints were evaluated in these studies which offered an extensive discussion on emerging modulators of endothelial functions. Specific factors such as reactive oxygen species had deleterious effects, especially in the obese and elderly. Another important finding included the shear stress-induced endothelial nitric oxide (NO), which may delay development of atherosclerosis. Perivascular Adipose Tissue (PVAT) also contributes to reparative measures against atherosclerosis, although this may turn pathological in obese subjects. Some of these factors may be targets for pharmaceutical agents in the near future.

CONCLUSION

The complex role and function of the endothelium is vital for regular homeostasis. Dysregulation may drive atherogenesis; thus, efforts should be placed at considering therapeutic options by targeting some of the factors noted.

Quality and Characteristics of 4241 Case Reports of Lactic Acidosis in Metformin Users Reported to a Large Pharmacovigilance Database

Objective

Metformin-associated lactic acidosis (MaLA) occurs rarely and is thus difficult to study. We analysed 4241 individual case safety reports of lactic acidosis (LA) that implicated metformin as a suspected drug reported to the pharmacovigilance database of Merck KGaA, Darmstadt, Germany. The primary objective was to review reports for quality and completeness of data to support diagnoses of MaLA. We also explored the correlations between reported biomarkers, and associations between biomarkers and outcomes.

Research Design and Methods

Records were analysed for completeness in supporting diagnoses of LA or metformin-associated LA (MaLA), against commonly used diagnostic criteria. Correlations between indices of exposure to metformin and biomarkers of LA and mortality were investigated.

Results

Missing data was common, especially for plasma metformin. Clinical/biomarker evidence supported a diagnosis of LA in only 33% of cases (LA subpopulation) and of MaLA in only 9% (MaLA subpopulation). The metformin plasma level correlated weakly with plasma lactate (positive) and pH (negative). About one-fifth (21.9%) of cases reported a fatal outcome. Metformin exposure (plasma level or dose) was not associated with increased mortality risk (there was a suggestion of decreased risk at higher levels of exposure to metformin). Plasma lactate was the only variable associated with increased risk of mortality. Examination of concomitant risk factors for MaLA identified renal dysfunction (including of iatrogenic origin) as a potential driver of mortality in this population.

Conclusion

Despite the high frequency of missing data, this is the largest analysis of cases of MaLA supported by measurements of circulating metformin, and lactate, and pH, to date. Plasma lactate, and not metformin dose or plasma level, appeared to be the main driver of mortality in the setting of LA or MaLA. Further research with more complete case reports is required.

Metformin Reduces the Incidence of Sensorineural Hearing Loss in Patients With Type 2 Diabetes Mellitus: A Retrospective Chart Review

Introduction and objectives

Acquired sensorineural hearing loss (SNHL) has become a critical societal issue in recent years. SNHL is considered a risk factor for type 2 diabetes mellitus (T2DM). Metformin is commonly used to treat T2DM. However, its effects on SNHL have not been reported yet. Hence, this study aimed to evaluate the association between the use of metformin and SNHL incidence.

Patients and methods

In this retrospective matched-cohort study, the medical records of 1219 patients with T2DM aged >18 years from our hospital’s inpatient database from January 1, 2012, to December 31, 2019, were examined, and matched cohorts were generated (76 patients receiving metformin and 76 not receiving metformin). A multivariable logistic regression analysis was performed to investigate the factors influencing the incidence of SNHL.

Results

After adjustment by propensity matching, multivariable logistic regression analysis revealed that the non-use of metformin increased the risk of developing SNHL (odds ratio, 0.26; 95% confidence interval, 0.07-0.93; p = 0.03).

Conclusions

This study demonstrated an association between the use of metformin and a reduced incidence of SNHL among patients with T2DM.

Metformin and risk of gingival/periodontal diseases in diabetes patients: A retrospective cohort study

AIM

To compare the risk of gingival and periodontal diseases (GPD) between ever users and never users of metformin in patients with type 2 diabetes mellitus.

METHODS

The Taiwan's National Health Insurance database was used to enroll 423,949 patients with new onset diabetes mellitus from 1999 to 2005. After excluding ineligible patients, 60,309 ever users and 5578 never users were followed up for the incidence of GPD from January 1, 2006 until December 31, 2011. Propensity score-weighted hazard ratios were estimated by Cox regression.

RESULTS

GPD was newly diagnosed in 18,528 ever users (incidence: 7746.51 per 100,000 person-years) and 2283 never users (incidence: 12158.59 per 100,000 person-years). The hazard ratio that compared ever users to never users was 0.627 (95% confidence interval: 0.600-0.655). When metformin use was categorized by tertiles of cumulative duration and cumulative dose, the risk significantly reduced in a dose-response pattern when the cumulative duration reached approximately 2 years or the cumulative dose reached 670 grams. Analyses on the tertiles of defined daily dose of metformin showed that the reduction of GPD risk could be seen in all three subgroups but the benefit would be greater when the daily dose increased.

CONCLUSION

Long-term use of metformin is associated with a significantly reduced risk of GPD.

COVID-19, Endothelium and the Cardiometabolic Patient: A Possible Role for Capillary Leak Syndrome

Capillary leak syndrome is an under-diagnosed condition leading to serious hypoalbuminemia with diffuse edema, pulmonary edema, severe hypotension, and possibly death. Sepsis leading to hemophagocytic lymphohistiocytosis (HLH) is a major risk factor; however, capillary hyper-permeability is the core underlying pathophysiological mechanism. Endothelial dysfunction plays a major role in cardiometabolic disease through insulin resistance, lipotoxicity, and, eventually, oxidative stress and chronic inflammation. We review the literature concerning the aforementioned mechanisms as well-established risk factors for adverse COVID-19 outcomes. We especially focus on data regarding the underlying endothelial effects of SARS-CoV-2 infection, including direct damage and increased vascular leakage through a hyper-inflammatory cascade and diminished nitric oxide bioavailability. Interestingly, an increased incidence of hypoalbuminemia has been observed in patients with severe COVID-19, especially those with underlying cardiometabolic disease. Importantly, low albumin levels present a strong, positive association with poor disease outcomes. Therefore, in this review article, we highlight the important role of cardiovascular risk factors on endothelium integrity and the possible link of endothelial damage in the hypoalbuminemia-associated adverse prognosis of COVID-19 patients.

Coronary Microvascular Dysfunction in Diabetes Mellitus: Pathogenetic Mechanisms and Potential Therapeutic Options

Diabetic patients are frequently affected by coronary microvascular dysfunction (CMD), a condition consisting of a combination of altered vasomotion and long-term structural change to coronary arterioles leading to impaired regulation of blood flow in response to changing cardiomyocyte oxygen requirements. The pathogenesis of this microvascular complication is complex and not completely known, involving several alterations among which hyperglycemia and insulin resistance play particularly central roles leading to oxidative stress, inflammatory activation and altered barrier function of endothelium. CMD significantly contributes to cardiac events such as angina or infarction without obstructive coronary artery disease, as well as heart failure, especially the phenotype associated with preserved ejection fraction, which greatly impact cardiovascular (CV) prognosis. To date, no treatments specifically target this vascular damage, but recent experimental studies and some clinical investigations have produced data in favor of potential beneficial effects on coronary micro vessels caused by two classes of glucose-lowering drugs: glucagon-like peptide 1 (GLP-1)-based therapy and inhibitors of sodium-glucose cotransporter-2 (SGLT2). The purpose of this review is to describe pathophysiological mechanisms, clinical manifestations of CMD with particular reference to diabetes, and to summarize the protective effects of antidiabetic drugs on the myocardial microvascular compartment.

Reactive Oxygen Species Scavenging Nanomedicine for the Treatment of Ischemic Heart Disease

Ischemic heart disease (IHD) is the leading cause of disability and mortality worldwide. Reactive oxygen species (ROS) have been shown to play key roles in the progression of diabetes, hypertension, and hypercholesterolemia, which are independent risk factors that lead to atherosclerosis and the development of IHD. Engineered biomaterial-based nanomedicines are under extensive investigation and exploration, serving as smart and multifunctional nanocarriers for synergistic therapeutic effect. Capitalizing on cell/molecule-targeting drug delivery, nanomedicines present enhanced specificity and safety with favorable pharmacokinetics and pharmacodynamics. Herein, the roles of ROS in both IHD and its risk factors are discussed, highlighting cardiovascular medications that have antioxidant properties, and summarizing the advantages, properties, and recent achievements of nanomedicines that have ROS scavenging capacity for the treatment of diabetes, hypertension, hypercholesterolemia, atherosclerosis, ischemia/reperfusion, and myocardial infarction. Finally, the current challenges of nanomedicines for ROS-scavenging treatment of IHD and possible future directions are discussed from a clinical perspective.

Upregulated miR-18a-5p in Colony Forming Unit-Hill’s in Subclinical Cardiovascular Disease and Metformin Therapy; MERIT Study

Colony forming unit-Hill’s (CFU-Hill’s) colonies are hematopoietic-derived cells that participate in neovasculogenesis and serve as a biomarker for vascular health. In animals, overexpression of miR-18a-5p was shown to be pro-atherogenic. We had shown that well-controlled type 1 diabetes mellitus (T1DM) is characterized by an inflammatory state, endothelial dysfunction, and reduced number of CFU-Hill’s, a model of subclinical cardiovascular disease (CVD). MERIT study explored the role of miR-18a-5p expression in CFU-Hill’s colonies in T1DM, and the cardioprotective effect of metformin in subclinical CVD. In T1DM, miR-18a-5p was significantly upregulated whereas metformin reduced it to HC levels. MiR-18a-5p was inversely correlated with CFU-Hill’s colonies, CD34+, CD34+CD133+ cells, and positively with IL-10, C-reactive protein, vascular endothelial growth factor-D (VEGF-D), and thrombomodulin. The receiver operating characteristic curve demonstrated, miR-18a-5p as a biomarker of T1DM, and upregulated miR-18a-5p defining subclinical CVD at HbA1c of 44.5 mmol/mol (pre-diabetes). Ingenuity pathway analysis documented miR-18a-5p inhibiting mRNA expression of insulin-like growth factor-1, estrogen receptor-1, hypoxia-inducible factor-1α cellular communication network factor-2, and protein inhibitor of activated STAT 3, whilst metformin upregulated these mRNAs via transforming growth factor beta-1 and VEGF. We confirmed the pro-atherogenic effect of miR-18a-5p in subclinical CVD and identified several target genes for future CVD therapies.

Endothelial Dysfunction, Erectile Deficit and Cardiovascular Disease: An Overview of the Pathogenetic Links

Erectile dysfunction (ED) is a condition with multifactorial pathogenesis, quite common among men, especially those above 60 years old. A vascular etiology is the most common cause. The interaction between chronic inflammation, androgens, and cardiovascular risk factors determines macroscopically invisible alterations such as endothelial dysfunction and subsequent atherosclerosis and flow-limiting stenosis that affects both penile and coronary arteries. Thus, ED and cardiovascular disease (CVD) should be considered two different manifestations of the same systemic disorder, with a shared aetiological factor being endothelial dysfunction. Moreover, the penile arteries have a smaller size compared with coronary arteries; thus, for the same level of arteriopathy, a more significant blood flow reduction will occur in erectile tissue compared with coronary circulation. As a result, ED often precedes CVD by 2–5 years, and its diagnosis offers a time window for cardiovascular risk mitigation. Growing evidence suggests, in fact, that patients presenting with ED should be investigated for CVD even if they have no symptoms. Early detection could facilitate prompt intervention and a reduction in long-term complications. In this review, we provide an overview of the pathogenetic mechanisms behind arteriogenic ED and CVD, focusing on the role of endothelial dysfunction as the common denominator of the two disorders. Developed algorithms that may help identify those patients complaining of ED who should undergo detailed cardiologic assessment and receive intensive treatment for risk factors are also analyzed.

Metformin: Is it a drug for all reasons and diseases?

Metformin was first used to treat type 2 diabetes in the late 1950s and in 2022 remains the first-choice drug used daily by approximately 150 million people. An accumulation of positive pre-clinical and clinical data has stimulated interest in re-purposing metformin to treat a variety of diseases including COVID-19. In polycystic ovary syndrome metformin improves insulin sensitivity. In type 1 diabetes metformin may help reduce the insulin dose. Meta-analysis and data from pre-clinical and clinical studies link metformin to a reduction in the incidence of cancer. Clinical trials, including MILES (Metformin In Longevity Study), and TAME (Targeting Aging with Metformin), have been designed to determine if metformin can offset aging and extend lifespan. Pre-clinical and clinical data suggest that metformin, via suppression of pro-inflammatory pathways, protection of mitochondria and vascular function, and direct actions on neuronal stem cells, may protect against neurodegenerative diseases. Metformin has also been studied for its anti-bacterial, -viral, -malaria efficacy. Collectively, these data raise the question: Is metformin a drug for all diseases? It remains unclear as to whether all of these putative beneficial effects are secondary to its actions as an anti-hyperglycemic and insulin-sensitizing drug, or result from other cellular actions, including inhibition of mTOR (mammalian target for rapamycin), or direct anti-viral actions. Clarification is also sought as to whether data from ex vivo studies based on the use of high concentrations of metformin can be translated into clinical benefits, or whether they reflect a 'Paracelsus' effect. The environmental impact of metformin, a drug with no known metabolites, is another emerging issue that has been linked to endocrine disruption in fish, and extensive use in T2D has also raised concerns over effects on human reproduction. The objectives for this review are to: 1) evaluate the putative mechanism(s) of action of metformin; 2) analyze the controversial evidence for metformin's effectiveness in the treatment of diseases other than type 2 diabetes; 3) assess the reproducibility of the data, and finally 4) reach an informed conclusion as to whether metformin is a drug for all diseases and reasons. We conclude that the primary clinical benefits of metformin result from its insulin-sensitizing and antihyperglycaemic effects that secondarily contribute to a reduced risk of a number of diseases and thereby enhancing healthspan. However, benefits like improving vascular endothelial function that are independent of effects on glucose homeostasis add to metformin's therapeutic actions.

Metformin: When Should We Fear Lactic Acidosis?

Metformin, a molecule belonging to the biguanide family, represents one of the most commonly prescribed medications for the treatment of diabetes mellitus in the world. Over the sixty years during which it has been used, many benefits have been described, which are not limited to the treatment of diabetes mellitus. However, since metformin is similar to other members of the same drug family, there is still much concern regarding the risk of lactic acidosis. This article aims to highlight the correlation between the use of metformin and the onset of renal damage or lactic acidosis. Metformin-associated lactic acidosis exists; however, it is rare. The appropriate use of the drug, under safe conditions, induces benefits without risks.

Metformin Serves as a Novel Drug Treatment for Arterial Thrombosis: Inhibitory Mechanisms on Collagen-Induced Human Platelet Activation

Metformin is widely used as first-line medication for type 2 diabetes (T2D), the main disease comorbid with kidney disease, cardiovascular diseases (CVDs), and retinopathy. Platelets are crucial in platelet-dependent arterial thrombosis, which causes CVDs and cerebrovascular diseases. Research indicates that metformin may improve these diseases; metformin reportedly reduced platelet activation in rats. However, no reports have included human platelets. We investigated the mechanisms underlying metformin’s effects on platelet activation by using human platelets and evaluated its in vivo effectiveness in experimental mice. Metformin inhibited platelet aggregation stimulated by collagen but not by arachidonic acid, U46619, or thrombin. Metformin suppressed ATP release, [Ca2+]i mobilization, and P-selectin expression, as well as phospholipase C (PLC)γ2/protein kinase C (PKC), p38 mitogen-activated protein kinase (MAPK), and phosphoinositide 3-kinase (PI3K)/Akt/glycogen synthase kinase-3β (GSK3β) phosphorylation. Metformin did not affect vasodilator-stimulated phosphoprotein (VASP) phosphorylation. In the animal studies, metformin reduced acute pulmonary thromboembolism mortality without increasing bleeding times. These results provide insights into the role and mechanisms of metformin in human platelet activation. Metformin decreased platelet activation by interfering with the PLCγ2/PKC, PI3K/Akt/GSK3β, and p38 MAPK pathways through a VASP-independent mechanism. Metformin demonstrates promise as a new class of antiplatelet agent that can inhibit platelet activation.

Triptolide alleviates ox-LDL-induced endothelial inflammation via attenuating the oxidative stress-mediated NF-κB pathway

Background

Endothelial inflammation triggered by oxidized LDL (ox-LDL) is a crucial mechanism involved in atherosclerosis. Triptolide (TP), a primary active ingredient of the traditional Chinese medicine Tripterygium wilfordii Hook F, possesses antioxidant and anti-inflammatory properties in vivo. However, limited information is available regarding these effects on endothelial inflammation occurring in atherosclerosis.

Objectives

This study investigated the effects and possible mechanisms of action of TP on ox–LDL-induced inflammatory responses in human umbilical vein endothelial cells.

Methods

Human umbilical vein endothelial cells were preincubated with TP at the indicated concentrations for 1 hour and then incubated with ox-LDL (50 µg/mL) for the indicated times.

Results

Preincubation of cultured human umbilical vein endothelial cells with TP inhibited ox–LDL-induced cytokine and chemokine production, adhesion molecule expression, and monocyte adhesion in a concentration-dependent manner. The concentrations of 8-isoprostane, malondialdehyde, and superoxide increased after human umbilical vein endothelial cells were exposed to ox-LDL, which were associated with decreased activities of total superoxide dismutase and its isoenzyme (ie, CuZn- superoxide dismutase). Preincubation with TP reversed ox–LDL-induced effects in all events. Moreover, preincubation with TP also attenuated ox–LDL-induced nuclear factor-kappa B transcriptional activation in a concentration-dependent manner, via the suppression of inhibitor of kappa Balpha (IκBα) phosphorylation and subsequent nuclear factor-kappa B DNA binding.

Conclusions

These data indicate that TP inhibits ox–LDL-induced endothelial inflammation, possibly via suppression of the oxidative stress-dependent activation of the nuclear factor-kappa B signaling pathway.

Endothelial Dysfunction Is Associated with Decreased Nitric Oxide Bioavailability in Dysglycaemic Subjects and First-Degree Relatives of Type 2 Diabetic Patients

Oxidative stress plays an important role in the pathogenesis of diabetes. We investigated oxidative stress and nitrite/nitrate concentrations at baseline and during postprandial hyperglycaemia in 40 first-degree relatives (FDRs) of diabetic patients with normal oral glucose tolerance test (OGTT) results, 40 subjects with abnormal OGTT results (dysglycaemic) and 20 subjects with normal OGTT results (normoglycaemic). Malondialdehyde (MDA), protein carbonyls (PCs), nitrite/nitrate plasma levels, the perfused boundary region (PBR—Glycocheck) of the sublingual microvessels, a marker of glycocalyx integrity, coronary flow reserve (CFR) and left ventricular global longitudinal strain (GLS) were assessed at 0 and 120 min of the OGTT. Insulin sensitivity was evaluated using Matsuda and the insulin sensitivity index (ISI). In all subjects, there were no significant changes in MDA or PC after the OGTT (p > 0.05). Compared with normoglycaemic subjects, FDRs and dysglycaemic subjects had significantly decreased nitrite/nitrate levels (−3% vs. −24% vs. −30%, respectively), an increased PBR and reduced CFR and GLS at 120 min (p < 0.05). The percent reduction in nitrite/nitrate was associated with abnormal Matsuda and ISI results, reversely related with the percent increase in PBR (r = −0.60) and positively related with the percent decrease in CFR (r = 0.39) and GLS (r = 0.48) (p < 0.05). Insulin resistance is associated with reduced nitric oxide bioavailability and coronary and myocardial dysfunction in FDRs and dysglycaemic subjects.

Empagliflozin-Metformin Combination Has Antioxidative and Anti-Inflammatory Properties that Correlate with Vascular Protection in Adults with Type 1 Diabetes

Methods

40 individuals with type 1 diabetes (average age of 44.7 ± 2.5 years) were randomized into four groups: (1) control (placebo), (2) empagliflozin 25 mg daily, (3) metformin 2000 mg daily, and (4) empagliflozin-metformin combination (25 mg and 2000 mg daily, respectively). At inclusion and after 12 weeks of treatment, the blood samples were collected, and the oxidative stress (total antioxidative status (TAS), superoxide dismutase (SOD), glutathione peroxidase (GPx), uric acid, advanced oxidation protein products (AOPP), advanced glycosylation end products ((AGE) and isoprostane), and inflammation (C-reactive protein (CRP) and interleukin-6 (IL-6)) parameters were determined.

Results

The empagliflozin-metformin combination increased levels of the antioxidants (TAS, SOD, and GPx up to 1.1-fold; P < 0.01), decreased the levels of prooxidants (AOPP and isoprostanes up to 1.2-fold, P < 0.01; AGE up to 1.5-fold, P < 0.01), and decreased inflammatory parameters (up to 1.5-fold, CRP P < 0.01; IL-6 P < 0.001). Antioxidative action was associated with the improvement in arterial function (obtained in the previous study) in the empagliflozin-metformin combination group.

Conclusion

Empagliflozin-metformin combination has strong antioxidative and anti-inflammatory capacity, in adults with type 1 diabetes that is greater than that for the individual drugs. Its antioxidative activity at least partially explains the improvement in arterial function. Therefore, it appears that the combination provides the most powerful vascular protection.