Effect of metformin on all-cause and cardiovascular mortality in patients with coronary artery diseases: a systematic review and an updated meta-analysis

Old drug, new tricks: the utility of metformin in infection and vaccination responses to influenza and SARS-CoV-2 in older adults

In the face of global pathogens such as influenza (flu) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), strategies beyond standard vaccines and virus-specific treatments are critically needed for older populations who are more susceptible to severe disease and death from these infections due to age-related immune dysregulation. Thus, complimentary therapeutics are needed to address the increased risk of complications and death in older adults. Metformin, an FDA approved diabetes drug, is an attractive therapeutic candidate to improve immune defenses and resilience in older adults facing viral challenge. Metformin is already a candidate anti-aging drug, but its benefits have potential to span beyond this and improve specific immune responses. Metformin can target multiple aging hallmarks as well as directly impact innate and adaptive immune cell subsets. Both retrospective and prospective studies have demonstrated metformin's efficacy in improving outcomes after SARS-CoV-2 or flu infections. Moreover, evidence from clinical trials has also suggested that metformin treatment can improve vaccination responses. In totality, these findings suggest that metformin can improve age-related declines in immunological resilience. Strategies to improve outcomes after infection or improve vaccine-induced protection are invaluable for older adults. Moreover, the ability to repurpose an already FDA approved drug has significant advantages in terms of necessary time and resources. Thus, metformin has great potential as a therapeutic to improve age-related immune dysregulation during flu and SARS-CoV-2 infections and should be further explored to confirm its ability to improve overall immunological resilience in older adults.

Drug-microbiota interactions: an emerging priority for precision medicine

Individual variability in drug response (IVDR) can be a major cause of adverse drug reactions (ADRs) and prolonged therapy, resulting in a substantial health and economic burden. Despite extensive research in pharmacogenomics regarding the impact of individual genetic background on pharmacokinetics (PK) and pharmacodynamics (PD), genetic diversity explains only a limited proportion of IVDR. The role of gut microbiota, also known as the second genome, and its metabolites in modulating therapeutic outcomes in human diseases have been highlighted by recent studies. Consequently, the burgeoning field of pharmacomicrobiomics aims to explore the correlation between microbiota variation and IVDR or ADRs. This review presents an up-to-date overview of the intricate interactions between gut microbiota and classical therapeutic agents for human systemic diseases, including cancer, cardiovascular diseases (CVDs), endocrine diseases, and others. We summarise how microbiota, directly and indirectly, modify the absorption, distribution, metabolism, and excretion (ADME) of drugs. Conversely, drugs can also modulate the composition and function of gut microbiota, leading to changes in microbial metabolism and immune response. We also discuss the practical challenges, strategies, and opportunities in this field, emphasizing the critical need to develop an innovative approach to multi-omics, integrate various data types, including human and microbiota genomic data, as well as translate lab data into clinical practice. To sum up, pharmacomicrobiomics represents a promising avenue to address IVDR and improve patient outcomes, and further research in this field is imperative to unlock its full potential for precision medicine.

Design and rationale of the myocardial infarction and new treatment with metformin study (MIMET) - Study protocol for a registry-based randomised clinical trial

AIMS

To investigate if addition of metformin to standard care (life-style advice) reduces the occurrence of cardiovascular events and death after myocardial infarction (MI) in patients with newly detected prediabetes.

METHODS

The Myocardial Infarction and new treatment with Metformin study (MIMET) is a large multicentre registry-based randomised clinical trial (R-RCT) within the SWEDEHEART registry platform expected to include 5160 patients with MI and newly detected prediabetes (identified with fasting blood glucose, HbA1c or 2-h glucose on oral glucose tolerance test) at ∼20 study sites in Sweden. Patients 18-80 years, without known diabetes and naïve to glucose lowering therapy, will be randomised 1:1 to open-label metformin therapy plus standard care or standard care alone.

OUTCOMES

Patients will be followed for 2 years for the primary outcome new cardiovascular event (first of death, non-fatal MI, hospitalisation for heart failure or non-fatal stroke). Secondary endpoints include individual components of the primary endpoint, diabetes diagnosis, initiation of any glucose lowering therapy, cancer, and treatment safety. Events will be collected from national healthcare registries.

CONCLUSIONS

The MIMET study will investigate if metformin is superior to standard care after myocardial infarction in preventing cardiovascular events in patients with prediabetes (Clinicaltrials.gov identifier: NCT05182970; EudraCT No: 2019-001487-30).

Metformin reduces the risk of developing influenza A virus related cardiovascular disease

This study investigated the drug repositioning potential of metformin for cardiovascular risk due to influenza A virus infection. Statistical analysis was performed to analyze factors related to the risk of death after IAV infection in diabetic patients. Through in vitro and in vivo experiments, the effect of metformin on influenza A virus infection in non-diabetic conditions was analyzed. In logistic regression analysis, influenza vaccination (OR = 0.378, p-value = 0.007, 0.186 < 95% C·I < 0.768) and metformin treatment (OR = 0.380, p-value = 0.016, 0.173 < 95% C·I < 0.835) were associated with a decreased influenza-related mortality in diabetic patients. In vitro and in vivo studies showed that viral replication and influenza A virus-induced cytokine expression were inhibited by metformin. In particular, MCP-1 and IP-10, cytokines related to cell infiltration and cardiovascular disease development, were significantly reduced by metformin under influenza A virus infection condition. As a result, the acute exacerbation of atherosclerosis caused by influenza A virus in mouse aorta was inhibited by metformin. In addition, we found that regulation of AKT/MAPK signaling plays an important role in the mechanism of metformin. In conclusion, we demonstrated the potential and mechanism of metformin as a treatment for acute exacerbation of atherosclerosis caused by influenza A virus infection.

Metformin mitigates radiation toxicity exerting antioxidant and genoprotective properties

The antidiabetic drug metformin (MF) exhibits redox-modulating effects in various pathologies associated with oxidative stress and mitigates ionizing radiation-induced toxicity, but the underlying mechanisms remain to be elucidated. Thus, we studied some radiomitigatory effects of MF and explored the possible mechanisms behind them. Highly sensitive luminescence methods and non-competitive enzyme-linked immunosorbent assay (ELISA) were used in in vitro studies, and in vivo the damage to bone marrow cells and its repair were assessed by the micronucleus test. In a solution, MF at concentrations exceeding 0.1 µM effectively intercepts •OH upon X-ray-irradiation, but does not react directly with H2O2. MF accelerates the decomposition of H2O2 catalyzed by copper ions. MF does not affect the radiation-induced formation of H2O2 in the solution of bovine gamma-globulin (BGG), but has a modulating effect on the generation of H2O2 in the solution of bovine serum albumin (BSA). MF at 0.05-1 mM decreases the radiation-induced formation of 8-oxoguanine in a DNA solution depending on the concentration of MF with a maximum at 0.25 mM. MF at doses of 3 mg/kg body weight (bw) and 30 mg/kg bw administered to mice after irradiation, but not before irradiation, reduces the frequency of micronucleus formation in polychromatophilic erythrocytes of mouse red bone marrow. Our work has shown that the radiomitigatory properties of MF are mediated by antioxidant mechanisms of action, possibly including its ability to chelate polyvalent metal ions.

Beyond Blood Sugar: Investigating the Cardiovascular Effects of Antidiabetic Drugs

Cardiovascular disease is a major comorbidity associated with diabetes mellitus. Various antidiabetic drugs are currently used to treat type 2 diabetes mellitus and have varying effects on the cardiovascular system. Some drugs, such as glucagon-like peptide 1 (GLP-1) agonists and sodium-glucose cotransporter 2 (SGLT-2) inhibitors, are cardioprotective, whereas others, such as insulin, have deleterious effects on the cardiovascular system. This narrative review assessed the impact of antidiabetic drugs on cardiovascular health in the management of diabetes mellitus. It critically examines various classes of these medications, including conventional options such as metformin and newer agents such as incretin-based therapies and SGLT-2.

A Systematic Approach to Treating Early Metabolic Disease and Prediabetes

At least 70% of US adults have metabolic disease. However, less is done to address early disease (e.g., overweight, obesity, prediabetes) versus advanced disease (e.g., type 2 diabetes mellitus, coronary artery disease). Given the burden of advanced metabolic disease and the burgeoning pandemics of obesity and prediabetes a systematic response is required. To accomplish this, we offer several recommendations: (A) Patients with overweight, obesity, and/or prediabetes must be consistently diagnosed with these conditions in medical records to enable population health initiatives. (B) Patients with early metabolic disease should be offered in-person or virtual lifestyle interventions commensurate with the findings of the Diabetes Prevention Program. (C) Patients unable to participate in or otherwise failing lifestyle intervention must be screened to assess if they require pharmacotherapy. (D) Patients not indicated for, refusing, or failing pharmacotherapy must be screened to assess if they need bariatric surgery. (E) Regardless of treatment approach or lack of treatment, patients must be consistently screened for the progression of early metabolic disease to advanced disease to enable early control. Progression of metabolic disease from an overweight yet otherwise healthy person includes the development of prediabetes, obesity ± prediabetes, dyslipidemia, hypertension, type 2 diabetes, chronic kidney disease, coronary artery disease, and heart failure. Systematic approaches in health systems must be deployed with clear protocols and supported by streamlined technologies to manage their population's metabolic health from early through advanced metabolic disease. Additional research is needed to identify and validate optimal system-level interventions. Future research needs to identify strategies to roll out systematic interventions for the treatment of early metabolic disease and to improve the metabolic health among the progressively younger patients being impacted by obesity and diabetes.

All-cause mortality and cardiovascular outcomes with sodium-glucose Co-transporter 2 inhibitors, glucagon-like peptide-1 receptor agonists and with combination therapy in people with type 2 diabetes

AIM

To assess the relationship of sodium-glucose cotransporter-2 inhibitors (SGLT2i), glucagon-like peptide-1 receptor analogues (GLP-1RA) and their combination (SGLT2i + GLP-1RA) with 5-year risk of all-cause mortality, hospitalization and cardiovascular/macrovascular disease in people with type 2 diabetes.

MATERIALS AND METHODS

Retrospective cohort analysis of 2.2 million people with type 2 diabetes receiving insulin across 85 health care organizations using a global federated health research network. Three intervention cohorts (SGLT2i, GLP-1RA and SGLT2i + GLP-1RA) were compared against a control cohort (no SGLT2i/GLP-1RA). Propensity score matching for age, ischaemic heart disease, sex, hypertension, chronic kidney disease, heart failure and glycated haemoglobin was used to balance cohorts 1:1 (SGLT2i, n = 143 600; GLP-1RA, n = 186 841; SGLT-2i + GLP-1RA, n = 108 504). A sub-analysis comparing combination and monotherapy cohorts was also performed.

RESULTS

The intervention cohorts showed a reduced hazard ratio (HR, 95% confidence interval) over 5 years compared with the control cohort for all-cause mortality (SGLT2i 0.49, 0.48-0.50; GLP-1RA 0.47, 0.46-0.48; combination 0.25, 0.24-0.26), hospitalization (0.73, 0.72-0.74; 0.69, 0.68-0.69; 0.60, 0.59-0.61) and acute myocardial infarct (0.75, 0.72-0.78; 0.70, 0.68-0.73; 0.63, 0.60-0.66), respectively. All other outcomes showed a significant risk reduction in favour of the intervention cohorts. The sub-analysis showed a significant risk reduction in all-cause mortality for combination therapy versus SGLT2i (0.53, 0.50-0.55) and GLP-1RA (0.56, 0.54-0.59).

CONCLUSIONS

SGLT2i, GLP-1RAs or combination therapy confers mortality and cardiovascular protection in people with type 2 diabetes over 5 years. Combination therapy was associated with the greatest risk reduction in all-cause mortality versus a propensity matched control cohort. In addition, combination therapy offers a reduction in 5-year all-cause mortality when compared directly against either monotherapy.

Impact of Fixed Combination of Metformin and Pioglitazone on Insulin Resistance of Patients with Type 2 Diabetes: Results of a Randomized Open-Label Study

Aim

To compare the effect of metformin, a fixed combination of metformin and pioglitazone, or dapagliflozin on insulin resistance in patients with newly diagnosed type 2 diabetes.

Methods

In this 6-week randomized open-label trial, 58 patients were randomly assigned to insulin with metformin, a fixed combination of metformin and pioglitazone, or dapagliflozin for 4 weeks. Hyperinsulinemic euglycemic clamp tests and FreeStyle Libre Pro Sensor were used to evaluate the insulin sensitivity represented by glucose-infusion rate (M value) and glycemic control, respectively. The main outcome was changes in insulin resistance compared with baseline.

Results

The baseline characteristics were well matched among the three groups. When compared to baseline, insulin sensitivity after treatment was significantly improved. Further study revealed that the fixed combination of metformin and pioglitazone provided superior M-value improvement compared with metformin, but not different from dapagliflozin. Moreover, a greater reduction in insulin dose was observed in the fixed combination of metformin and pioglitazone group than the metformin or dapagliflozin group. However, there were no significant differences in the parameters of glycemic control within the groups.

Conclusion

In patients with newly diagnosed type 2 diabetes, a fixed combination of metformin and pioglitazone provided greater improvement in insulin resistance than metformin alone and similar changes in insulin resistance to dapagliflozin.

Metformin effects on cardiac parameters in non-diabetic Iraqi patients with heart failure and mid-range ejection fraction - a comparative two-arm parallel clinical study

Heart failure (HF) remains a difficult challenge to the healthcare system, necessitating promoting interventions and multidrug management. Metformin, typically used to manage diabetes, has emerged as a promising intervention in the treatment of HF. This study aimed to assess the effect of adding metformin to the standard treatment of HF on cardiac parameters. This clinical study comprised 60 newly diagnosed HF patients randomly assigned to two groups: Group C received standard HF treatment, while Group M received standard HF treatment in addition to daily metformin (500 mg). After 3 months of treatment, group M showed a significantly higher ejection fraction (EF) compared to Group C (6.1% and 3.2%, respectively; p-value=0.023) and a reduction in the left ventricular end-diastolic pressure (LVEDD) (0.28, and 0.21 mm respectively; p-value=0.029). No significant differences were observed in the interventricular septal thickness (IVST) or left ventricular end-systolic pressure (LVESD). For cardiac markers, N-Terminal pro-BNP (NT-proBNP) showed the highest reduction in Group M compared to Group C (719.9 pg/ml and 271.9 pg/ml respectively; p-value=0.009). No significant changes were reported for soluble ST2. Metformin demonstrated cardiac protective effects by increasing EF and reducing NT-proBNP. Given its affordability and accessibility, metformin offers a valuable addition to the current HF treatment options. This positive effect may be attributed to mechanisms that enhance the impact of conventional HF treatments or vice versa.

Metformin-mediated epigenetic modifications in diabetes and associated conditions: Biological and clinical relevance

An intricate interplay between genetic and environmental factors contributes to the development of type 2 diabetes (T2D) and its complications. Therefore, it is not surprising that the epigenome also plays a crucial role in the pathogenesis of T2D. Hyperglycemia can indeed trigger epigenetic modifications, thereby regulating different gene expression patterns. Such epigenetic changes can persist after normalizing serum glucose concentrations, suggesting the presence of a 'metabolic memory' of previous hyperglycemia which may also be epigenetically regulated. Metformin, a derivative of biguanide known to reduce serum glucose concentrations in patients with T2D, appears to exert additional pleiotropic effects that are mediated by multiple epigenetic modifications. Such modifications have been reported in various organs, tissues, and cellular compartments and appear to account for the effects of metformin on glycemic control as well as local and systemic inflammation, oxidant stress, and fibrosis. This review discusses the emerging evidence regarding the reported metformin-mediated epigenetic modifications, particularly on short and long non-coding RNAs, DNA methylation, and histone proteins post-translational modifications, their biological and clinical significance, potential therapeutic applications, and future research directions.

Metformin Impedes Oxidation of LDL In Vitro

Metformin is the most commonly prescribed glucose-lowering drug for the treatment of type 2 diabetes. The aim of this study was to investigate whether metformin is capable of impeding the oxidation of LDL, a crucial step in the development of endothelial dysfunction and atherosclerosis. LDL was oxidized by addition of CuCl2 in the presence of increasing concentrations of metformin. The extent of LDL oxidation was assessed by measuring lipid hydroperoxide and malondialdehyde concentrations, relative electrophoretic mobilities, and oxidation-specific immune epitopes. Cytotoxicity of oxLDL in the vascular endothelial cell line EA.hy926 was assessed using the alamarBlue viability test. Quantum chemical calculations were performed to determine free energies of reactions between metformin and radicals typical for lipid oxidation. Metformin concentration-dependently impeded the formation of lipid hydroperoxides, malondialdehyde, and oxidation-specific immune epitopes when oxidation of LDL was initiated by addition of Cu2+. The cytotoxicity of oxLDL was reduced when it was obtained under increasing concentrations of metformin. The quantum chemical calculations revealed that only the reaction of metformin with hydroxyl radicals is exergonic, whereas the reactions with hydroperoxyl radicals or superoxide radical anions are endergonic. Metformin, beside its glucose-lowering effect, might be a suitable agent to impede the development of atherosclerosis and associated CVD. This is due to its capability to impede LDL oxidation, most likely by scavenging hydroxyl radicals.

Metformin protects against pulmonary hypertension-induced right ventricular dysfunction in an age- and sex-specific manner independent of cardiac AMPK

Right ventricular (RV) function is the strongest predictor of survival in age-related heart failure as well as other clinical contexts in which aging populations suffer significant morbidity and mortality. However, despite the significance of maintaining RV function with age and disease, mechanisms of RV failure remain poorly understood and no RV-directed therapies exist. The antidiabetic drug and AMP-activated protein kinase (AMPK) activator metformin protects against left ventricular dysfunction, suggesting cardioprotective properties may translate to the RV. Here, we aimed to understand the impact of advanced age on pulmonary hypertension (PH)-induced right ventricular dysfunction. We further aimed to test whether metformin is cardioprotective in the RV and whether the protection afforded by metformin requires cardiac AMPK. We used a murine model of PH by exposing adult (4-6 mo) and aged (18 mo) male and female mice to hypobaric hypoxia (HH) for 4 wk. Cardiopulmonary remodeling was exacerbated in aged mice compared with adult mice as evidenced by elevated RV weight and impaired RV systolic function. Metformin attenuated HH-induced RV dysfunction but only in adult male mice. Metformin still protected the adult male RV even in the absence of cardiac AMPK. Together, we suggest that aging exacerbates PH-induced RV remodeling and that metformin may represent a therapeutic option for this disease in a sex- and age-dependent manner, but in an AMPK-independent manner. Ongoing efforts are aimed at elucidating the molecular basis for RV remodeling as well as delineating the mechanisms of cardioprotection provided by metformin in the absence of cardiac AMPK.NEW & NOTEWORTHY Right ventricular (RV) function predicts survival in age-related disease, yet mechanisms of RV failure are unclear. We show that aged mice undergo exacerbated RV remodeling compared with young. We tested the AMPK activator metformin to improve RV function and show that metformin attenuates RV remodeling only in adult male mice via a mechanism that does not require cardiac AMPK. Metformin is therapeutic for RV dysfunction in an age- and sex-specific manner independent of cardiac AMPK.

Association of Metformin Use with Iron Deficiency Anemia in Urban Chinese Patients with Type 2 Diabetes

BACKGROUND

Previous evidence yielded contradictory findings on the relationship between metformin and anemia. This study aims to assess whether metformin use is associated with iron-deficiency anemia (IDA) risk in patients with type 2 diabetes (T2D) in Beijing, China.

METHODS

Overall, 60,327 newly diagnosed T2D patients were included based on a historical cohort study design. The information pertaining to these patients was gathered from the Beijing Medical Claim Data for Employees Database. These patients were then categorized into the metformin and non-metformin groups and matched on a 1:1 propensity score based on their initial antidiabetic prescription. The Cox proportional hazards models were utilized to calculate the incidences and the hazard ratios (HRs).

RESULTS

The study enrolled 27,960 patients with type 2 diabetes, with 13,980 patients in each of the initial glucose-lowering prescription groups: metformin and non-metformin. During a median follow-up period of 4.84 years, 4832 patients developed IDA. The incidence of IDA was significantly lower in the metformin group (26.08/1000 person-years) than in the non-metformin group (43.20/1000 person-years). Among the three groups divided by the proportion of days covered by metformin, we found a negative correlation between the proportion of days covered by metformin and the risk of IDA. The risk of IDA in patients with a proportion of days covered by metformin of <20%, 20-79%, and ≥80% was 0.43 (0.38, 0.48), 0.37 (0.34, 0.42), and 0.91 (0.85, 0.98), respectively, compared to the non-metformin group. We also performed subgroup analyses and sensitivity analyses: the incidence of IDA in the metformin group was lower than that in the non-metformin group in all subgroups, and the protective effect was more significant in subgroups of patients aged ≥65, with Charlson comorbidity index (CCI) ≥2, and with gastric acid inhibitor use.

CONCLUSIONS

In Chinese patients with T2DM, metformin treatment was associated with a decreased risk of IDA admission, and this risk responded positively to the proportion of days covered by metformin. These findings suggest that metformin may have a pleiotropic effect on IDA in patients with type 2 diabetes. Our study has important clinical implications for the management of patients with diabetes and other conditions that increase the risk of IDA.

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.

The development and benefits of metformin in various diseases

Metformin has been used for the treatment of type II diabetes mellitus for decades due to its safety, low cost, and outstanding hypoglycemic effect clinically. The mechanisms underlying these benefits are complex and still not fully understood. Inhibition of mitochondrial respiratory-chain complex I is the most described downstream mechanism of metformin, leading to reduced ATP production and activation of AMP-activated protein kinase (AMPK). Meanwhile, many novel targets of metformin have been gradually discovered. In recent years, multiple pre-clinical and clinical studies are committed to extend the indications of metformin in addition to diabetes. Herein, we summarized the benefits of metformin in four types of diseases, including metabolic associated diseases, cancer, aging and age-related diseases, neurological disorders. We comprehensively discussed the pharmacokinetic properties and the mechanisms of action, treatment strategies, the clinical application, the potential risk of metformin in various diseases. This review provides a brief summary of the benefits and concerns of metformin, aiming to interest scientists to consider and explore the common and specific mechanisms and guiding for the further research. Although there have been countless studies of metformin, longitudinal research in each field is still much warranted.

Glycemic outcomes of people with diabetes mellitus in Brazilian primary health care

Background

The capillary blood glucose monitoring program at home a challenge in primary health care. Therefore, it is fundamental to identify the glycemic control of people with diabetes mellitus through HBA1c and to analyze its associated factors.

Objective

To identify the glycemic profile of people with Diabetes Mellitus (DM) through HbA1c and analyze factors associated.

Materials & methods

Cross-sectional study developed in Ribeirão Preto, São Paulo, Brazil. Secondary data from the electronic health record of people registered in the Primary Health Care system were used. A sample of 3181 participants was obtained. People with HbA1c < 7.0% (53 mmol/mol) were considered to have adequate glycemic control. For people aged ≥ 55 years, a less stringent target, < 8.0% (64 mmol/mol), was also considered. The odds ratio was the measure of effect analyzed with their respective 95% Confidence Intervals (95% CI).

Results

Adequate glycemic control with HbA1c < 7.0% (53 mmol/mol) was found in 44.8% of people and, when using the less rigid target, HbA1c < 8.0% (64 mmol/mol) for people aged ≥ 55 years-old, 70.6% had adequate glycemic control. Age and drug therapy were associated with adequate glycemic control (p < 0.001), which was more frequent among older people and those who used only metformin.

Conclusion

The study shows that the achievement of adequate glycemic control is still a challenge, especially with regard to younger people and those who use insulin.

Metformin Use Is Associated With Lower Mortality in Veterans With Diabetes Hospitalized With Pneumonia

BACKGROUND

Recent studies suggest that metformin use may be associated with improved infectious disease-related outcomes, whereas other papers suggest potentially worse outcomes in serious bacterial infections. Our purpose was to examine the association of prior outpatient prescription of metformin on 30- and 90-day mortality for older veterans with pre-existing diabetes hospitalized with pneumonia.

METHODS

We conducted a retrospective cohort study using national Department of Veterans Affairs data of patients ≥65 years with a prior history of diabetes who were hospitalized with pneumonia over a 10-year period (fiscal years 2002-2012.) For our primary analysis, we created a propensity score and matched metformin users to nonusers 1:1.

RESULTS

We identified 34 759 patients who met the inclusion criteria, 20.3% of whom were prescribed metformin. Unadjusted 30-day mortality was 9.6% for those who received metformin versus 13.9% in nonusers (P < .003), and 90-day mortality was 15.8% for those who received metformin versus 23.0% for nonusers (P < .0001). For the propensity score model, we matched 6899 metformin users to 6899 nonusers. After propensity matching, both 30-day (relative risk [RR]: .86; 95% confidence interval [CI]: .78-.95) and 90-day (RR: .85; 95% CI: .79-.92) mortality was significantly lower for metformin users.

CONCLUSIONS

Prior receipt of metformin was associated with significantly lower mortality after adjusting for potential confounders. Additional research is needed to examine the safety and potential benefits of metformin use in patients with respiratory infections.

The function, mechanisms, and clinical applications of metformin: potential drug, unlimited potentials

Metformin has been used clinically for more than 60 years. As time goes by, more and more miraculous effects of metformin beyond the clinic have been discovered and discussed. In addition to the clinically approved hypoglycemic effect, it also has a positive metabolic regulation effect on the human body that cannot be ignored. Such as anti-cancer, anti-aging, brain repair, cardiovascular protection, gastrointestinal regulation, hair growth and inhibition of thyroid nodules, and other nonclinical effects. Metformin affects almost the entire body in the situation taking it over a long period, and the preventive effects of metformin in addition to treating diabetes are also beginning to be recommended in some guidelines. This review is mainly composed of four parts: the development history of metformin, the progress of clinical efficacy, the nonclinical efficacy of metformin, and the consideration and prospect of its application.

Metformin pretreatment potentiates the antiproliferative action of doxorubicin against breast cancer

OBJECTIVES

The present study aimed to evaluate the effect of metformin pretreatment on the potentiation of antiproliferative action of doxorubicin against breast cancer.

MATERIAL AND METHODS

Female Wistar rats were administered with 7,12-Dimethylbenz(a)anthracene (DMBA) (35mg) in 1mL olive oil subcutaneously beneath the mammary gland. Animals were pretreated with metformin (Met) 200mg/kg two weeks before DMBA administration. DMBA control groups received doxorubicin (Dox) (4mg/kg and 2mg/kg), Met (200mg/kg) alone and in combination with Dox (4mg/kg). Met pre-treated DMBA control groups received Dox 4mg/kg and 2mg/kg.

RESULTS

Met pre-treated groups treated with Dox exhibited a decrease in tumor incidence, tumor volume and increased survival rate than the DMBA group. Organ-to-body weight ratios and histopathology of heart, liver and lungs of Met pre-treated groups treated with Dox showed lesser toxicity than Dox treated DMBA control groups. There was a noteworthy decrease in malondialdehyde levels and a substantial increase in the levels of reduced glutathione together with a significant decrease in the levels of inflammatory markers like IL-6, IL-1β and NF-κB in Met pre-treated groups treated with Dox. Histopathology of breast tumors revealed better control of tumors in Met pre-treated groups treated with Dox than DMBA control group. Immunohistochemistry and real-time PCR data revealed a significant reduction in Ki67 expression in Met pre-treated groups treated with Dox as compared to the DMBA control group.

CONCLUSION

The present study suggests that metformin pretreatment potentiates the antiproliferative action of doxorubicin against breast cancer.

Substituent effects of sulfonamide derivatives of metformin that can dually improve cellular glucose utilization and anti-coagulation

Metformin, the most frequently prescribed medicine for the management of type 2 diabetes, has been shown to reduce cardiovascular events in diabetic patients in pre-clinical and clinical studies. The present work reports the design, synthesis, and biological assessment of the impact of six benzenesulfonamide biguanides on various aspects of hemostasis, cell function, red blood cell integrity (RBC), and their ability to uptake glucose in human umbilical endothelial cells (HUVECs). It was found that all synthesized o- and m-benzenesulfonamides, particularly derivatives with nitro (3) and amino groups (4), are characterized by a good safety profile in HUVECs, which was further confirmed in the cellular integrity studies. The biguanide analogues with methoxy group (1, 2) and an amino substituent (5, 6) significantly increased glucose utilization in HUVECs, similarly to the parent drug. Intriguingly, compounds 1, 3, and 6 favourably influenced some of the coagulation parameters. Furthermore, derivative 3 also slowed the process of fibrin polymerization, indicating more beneficial anti-coagulant properties than metformin. None of the novel metformin analogues interact strongly with the erythrocyte lipid-protein bilayer. Our findings indicate that derivative 3 has highly desirable anti-coagulant properties, and compounds 1 and 6 have potential dual-action activity, including anti-hyperglycaemic properties and anti-coagulant activity. As such, these derivatives can be used as lead molecules for further development of anti-diabetic agents with a beneficial effect on hypercoagulability.

Metformin: new applications for an old drug

Metformin is a biguanide, evolved as one of the most widely used medicines. The applications of this component include but are not limited to reducing blood glucose, weight loss, and polycystic ovary syndrome. Studies about other probable indications have emerged, indicating that this agent can also be utilized for other purposes. In this review, applications of metformin are noticed based on the current evidence. Metformin commonly is used as an off-label drug in non-alcoholic fatty liver disease (NAFLD), but it worsens inflammation and should not be used for this purpose, according to the latest research. Metformin decreased the risk of death in patients with liver cirrhosis. It is an effective agent in the prevention and improvement of survival in patients suffering hepatocellular carcinoma. There is evidence of the beneficial effects of metformin in colorectal cancer, early-stage prostate cancer, breast cancer, urothelial cancer, blood cancer, melanoma, and bone cancer, suggesting metformin as a potent anti-tumor agent. Metformin shows neuroprotective effects and provides a potential therapeutic benefit for mild cognitive impairment and Alzheimer's disease (AD). It also has been shown to improve mental function and reduce the incidence of dementia. Another condition that metformin has been shown to slow the progression of is Duchenne muscular dystrophy. Regarding infectious diseases, tuberculosis (TB) and coronavirus disease (COVID-19) are among the conditions suggested to be affected by metformin. The beneficial effects of metformin in cardiovascular diseases were also reported in the literature. Concerning renal function, studies showed that daily oral administration of metformin could ameliorate kidney fibrosis and normalize kidney structure and function. This study reviewed the clinical and preclinical evidence about the possible benefits of metformin based on recent studies. Numerous questions like whether these probable indications of metformin can be observed in non-diabetics, need to be described by future basic experiments and clinical studies.

The modifier effect of physical activity, body mass index, and age on the association of metformin and chronic back pain: A cross-sectional analysis of 21,899 participants from the UK Biobank

BACKGROUND

There is growing evidence of the anti-inflammatory effect of the anti-diabetic drug metformin and its use to reduce pain. However, we currently lack studies investigating whether metformin is associated with a reduction in chronic back pain prevalence when considering physical activity levels, body mass index (BMI), and age.

OBJECTIVE

To investigate whether use of metformin is associated with lower levels of reporting of chronic back pain in a large cohort with type 2 diabetes when stratified for physical activity, BMI, and age.

METHODS

This is a cross-sectional study of 21,889 participants with type 2 diabetes who were drawn from the UK Biobank database. We investigated whether people using metformin reported a higher prevalence of chronic low back pain than those who did not. Type 2 diabetes, chronic back pain, and metformin were self-reported. Participants were stratified according to their physical activity level (low, moderate and high), BMI (normal, overweight, and obese), and age (40 to <50; 50 to < 60; and ≥60 years). Logistic regression models were built for each physical activity level, BMI and age category to investigate the prevalence of chronic back pain amongst those using and not using metformin.

RESULTS

Participants who were using metformin and who had low levels of physical activity [OR 0.87, 95%CI 0.78 to 0.96] or who were obese [OR 0.90, 95%CI 0.86 to 0.98] or older [OR 0.85, 95%CI 0.78 to 0.93] had lower odds of reporting chronic back pain than their counterparts.

CONCLUSION

The anti-diabetic drug metformin might reduce prevalence of chronic low back pain in people who are older, overweight, or less active. These findings should be confirmed in studies using a longitudinal design.

Approved Nanomedicine against Diseases

Nanomedicine is a branch of medicine using nanotechnology to prevent and treat diseases. Nanotechnology represents one of the most effective approaches in elevating a drug's treatment efficacy and reducing toxicity by improving drug solubility, altering biodistribution, and controlling the release. The development of nanotechnology and materials has brought a profound revolution to medicine, significantly affecting the treatment of various major diseases such as cancer, injection, and cardiovascular diseases. Nanomedicine has experienced explosive growth in the past few years. Although the clinical transition of nanomedicine is not very satisfactory, traditional drugs still occupy a dominant position in formulation development, but increasingly active drugs have adopted nanoscale forms to limit side effects and improve efficacy. The review summarized the approved nanomedicine, its indications, and the properties of commonly used nanocarriers and nanotechnology.

Clinical Application of Metformin Use in Anhui Province, China: A Cross-Sectional Study

Purpose

Given the importance of metformin, reasonable utilization is essential. We designed a cross-sectional survey on physicians' attitude and clinical application of metformin in Anhui Province, China.

Methods

The survey was distributed via an electronic questionnaire among endocrinologists and general practitioners. Seven representative questions were used to evaluate professional levels.

Results

Among the 477 valid responses, 72.75% of the respondents preferred to prescribe metformin extended-release, while only 34.38% of them would prescribe metformin extended-release at the correct frequency. More than half of the respondents thought that estimated glomerular filtration rate ˂ 45 mL/min/1.73 m² should be the contraindication of metformin prescription. Less than 10% of the physicians selected correct responses for two questions regarding metformin usage and contrast agent. Physicians with higher levels of hospital grades, education background and professional titles as well as working in general hospitals and in the Department of Endocrinology achieved high scores (P˂0.05). Logistic regression showed that department was an independent predictor for high scores.

Conclusion

Physicians, especially non-endocrinologists, are not at a professional level for prescribing metformin. Physicians should be highly vigilant in terms of standardized prescription for metformin. The guidelines or consensuses about diabetes care for physicians should be promoted.

Cellular Senescence and Ageing

Cellular senescence has become a subject of great interest within the ageing research field over the last 60 years, from the first observation in vitro by Leonard Hayflick and Paul Moorhead in 1961, to novel findings of phenotypic sub-types and senescence-like phenotype in post-mitotic cells. It has essential roles in wound healing, tumour suppression and the very first stages of human development, while causing widespread damage and dysfunction with age leading to a raft of age-related diseases. This chapter discusses these roles and their interlinking pathways, and how the observed accumulation of senescent cells with age has initiated a whole new field of ageing research, covering pathologies in the heart, liver, kidneys, muscles, brain and bone. This chapter will also examine how senescent cell accumulation presents in these different tissues, along with their roles in disease development. Finally, there is much focus on developing treatments for senescent cell accumulation in advanced age as a method of alleviating age-related disease. We will discuss here the various senolytic and senostatic treatment approaches and their successes and limitations, and the innovative new strategies being developed to address the differing effects of cellular senescence in ageing and disease.

Hyperinsulinemia and plasma glucose level independently associated with all-cause and cardiovascular mortality in Chinese people without diabetes-A post-hoc analysis of the 30-year follow-up of Da Qing diabetes and IGT study

AIMS

We aimed to characterize the effect of insulin resistance and plasma glucose on all-cause and cardiovascular disease (CVD) death.

METHODS

A total of 462 individuals without diabetes in the original Da Qing Diabetes and IGT Study were enrolled in the present analysis, and further divided into G1 (low insulin low glucose), G2 (high insulin low glucose), G3 (low insulin high glucose) and G4 (high insulin high glucose) groups according to medians of glucose and insulin level at baseline. The all-cause and CVD death were assessed from 1986 to 2016.

RESULTS

During the 30-year follow-up, compared with G1, G2, G3, and G4 groups were all at increased death risk after adjusting covariates. G2 and G3 were associated with similar risks in both all-cause (G2: HR 1.65, 95%CI 1.02-2.67; G3: HR 1.76, 95%CI 1.11-2.81) and CVD death (G2: HR 2.03, 95%CI 1.01-4.05; G3: HR 1.85, 95%CI 0.93-3.68). The highest risk was observed in G4 (all-cause death: HR 2.32, 95%CI 1.45-3.69; CVD death: HR 2.68, 95%CI 1.35-5.29).

CONCLUSIONS

In this post-hoc study, participants with either high glucose or high insulin were related to increased risk of mortality, implying that strategies targeting eliminating both hyperglycemia and hyperinsulinemia may favor the long-term outcomes.

Metformin in therapeutic applications in human diseases: its mechanism of action and clinical study

Metformin, a biguanide drug, is the most commonly used first-line medication for type 2 diabetes mellites due to its outstanding glucose-lowering ability. After oral administration of 1 g, metformin peaked plasma concentration of approximately 20-30 μM in 3 h, and then it mainly accumulated in the gastrointestinal tract, liver and kidney. Substantial studies have indicated that metformin exerts its beneficial or deleterious effect by multiple mechanisms, apart from AMPK-dependent mechanism, also including several AMPK-independent mechanisms, such as restoring of redox balance, affecting mitochondrial function, modulating gut microbiome and regulating several other signals, such as FBP1, PP2A, FGF21, SIRT1 and mTOR. On the basis of these multiple mechanisms, researchers tried to repurpose this old drug and further explored the possible indications and adverse effects of metformin. Through investigating with clinical studies, researchers concluded that in addition to decreasing cardiovascular events and anti-obesity, metformin is also beneficial for neurodegenerative disease, polycystic ovary syndrome, aging, cancer and COVID-19, however, it also induces some adverse effects, such as gastrointestinal complaints, lactic acidosis, vitamin B12 deficiency, neurodegenerative disease and offspring impairment. Of note, the dose of metformin used in most studies is much higher than its clinically relevant dose, which may cast doubt on the actual effects of metformin on these disease in the clinic. This review summarizes these research developments on the mechanism of action and clinical evidence of metformin and discusses its therapeutic potential and clinical safety.

A blast from the past: To tame time with metformin

The strong evidence of metformin use in subjects affected by type 2 diabetes (T2DM) on health outcomes, together with data from pre-clinical studies, has led the gerontological research to study the therapeutic potential of such a drug as a slow-aging strategy. However, despite clinical use for over fifty years as an anti-diabetic drug, the mechanisms of action beyond glycemic control remain unclear. In this review, we have deeply examined the literature, doing a narrative review from the metformin story, through mechanisms of action to slow down aging potential, from lower organisms to humans. Based on the available evidence, we conclude that metformin, as shown in lower organisms and mice, may be effective in humans' longevity. A complete analysis and follow-up of ongoing clinical trials may provide more definitive answers as to whether metformin should be promoted beyond its use to treat T2DM as a drug that enhances both healthspan and lifespan.

Comparison of Mitochondrial Adenosine Triphosphate-Sensitive Potassium Channel High- vs Low-Affinity Sulfonylureas and Cardiovascular Outcomes in Patients With Type 2 Diabetes Treated With Metformin

IMPORTANCE

Sulfonylureas are frequently used as add-on to metformin in type 2 diabetes (T2D), and individual sulfonylurea agents carry different risks of cardiovascular disease. Sulfonylureas' different affinities to cardiac mitochondrial adenosine triphosphate-sensitive potassium (mitoKATP) channels have been speculated to account for the intraclass difference in cardiovascular risk from in vitro and ex vivo studies; however, this hypothesis has not been assessed in a general population with diabetes receiving sulfonylureas added to metformin.

OBJECTIVE

To compare the risk of myocardial infarction (MI), ischemic stroke, or cardiovascular death in patients with T2D treated with mitoKATP channel high-affinity sulfonylureas and low-affinity sulfonylureas as add-on to metformin.

DESIGN, SETTING, AND PARTICIPANTS

This is a new-user, active-comparator, and propensity score-matched cohort study with analysis of the Taiwanese Diabetes Mellitus Health Database from 2006, to 2017. Data analysis was performed from August 2020 to July 2021.

EXPOSURES

Cardiac mitoKATP channel high-affinity (glyburide and glipizide) and low-affinity (gliclazide and glimepiride) sulfonylureas combined with metformin.

MAIN OUTCOMES AND MEASURES

Primary outcome was major adverse cardiovascular events (MACEs), a composite of cardiovascular death or hospitalization for either MI or ischemic stroke. Secondary outcomes included individual MACE components, heart failure, arrhythmia, all-cause mortality, and severe hypoglycemia. Cox proportional hazards models were used to estimate adjusted hazard ratios (aHRs).

RESULTS

Each sulfonylurea group comprised 53 714 patients (mean [SD] age, 54.7 [12.1] years; 31 962 men [59.5%]). MitoKATP channel high-affinity sulfonylureas vs low-affinity sulfonylureas when combined with metformin were associated with an increased risk of MACE (aHR, 1.18; 95% CI, 1.03-1.34), MI (aHR, 1.34; 95% CI, 1.04-1.73), all-cause mortality (aHR, 1.27; 95% CI, 1.03-1.57), and severe hypoglycemia (aHR, 1.82; 95% CI, 1.58-2.10), but not with increased risks of ischemic stroke, cardiovascular death, arrhythmia, and heart failure. The duration analyses revealed the highest MACE risk during 1 to 90 days after initiation of mitoKATP channel high-affinity sulfonylureas (aHR, 6.06; 95% CI, 4.86-7.55).

CONCLUSIONS AND RELEVANCE

Use of mitoKATP channel high-affinity sulfonylureas vs low-affinity sulfonylureas was associated with an increased MACE risk in patients with T2D concomitantly receiving metformin, suggesting that high-affinity blockage of the mitoKATP channels could account for sulfonylurea-associated MACEs.

The Impact of Cardiac Comorbidity Sequence at Baseline and Mortality Risk in Type 2 Diabetes Mellitus: A Retrospective Population-Based Cohort Study

Introduction: The presence of multiple comorbidities increases the risk of all-cause mortality, but the effects of the comorbidity sequence before the baseline date on mortality remain unexplored. This study investigated the relationship between coronary heart disease (CHD), atrial fibrillation (AF) and heart failure (HF) through their sequence of development and the effect on all-cause mortality risk in type 2 diabetes mellitus. Methods: This study included patients with type 2 diabetes mellitus prescribed antidiabetic/cardiovascular medications in public hospitals of Hong Kong between 1 January 2009 and 31 December 2009, with follow-up until death or 31 December 2019. The Cox regression was used to identify comorbidity sequences predicting all-cause mortality in patients with different medication subgroups. Results: A total of 249,291 patients (age: 66.0 ± 12.4 years, 47.4% male) were included. At baseline, 7564, 10,900 and 25,589 patients had AF, HF and CHD, respectively. Over follow-up (3524 ± 1218 days), 85,870 patients died (mortality rate: 35.7 per 1000 person-years). Sulphonylurea users with CHD developing later and insulin users with CHD developing earlier in the disease course had lower mortality risks. Amongst insulin users with two of the three comorbidities, those with CHD with preceding AF (hazard ratio (HR): 3.06, 95% CI: [2.60−3.61], p < 0.001) or HF (HR: 3.84 [3.47−4.24], p < 0.001) had a higher mortality. In users of lipid-lowering agents with all three comorbidities, those with preceding AF had a higher risk of mortality (AF-CHD-HF: HR: 3.22, [2.24−4.61], p < 0.001; AF-HF-CHD: HR: 3.71, [2.66−5.16], p < 0.001). Conclusions: The sequence of comorbidity development affects the risk of all-cause mortality to varying degrees in diabetic patients on different antidiabetic/cardiovascular medications.

Anthracycline-induced cardiotoxicity and senescence

Cancer continues to place a heavy burden on healthcare systems around the world. Although cancer survivorship continues to improve, cardiotoxicity leading to cardiomyopathy and heart failure as a consequence of cancer therapy is rising, and yesterday's cancer survivors are fast becoming today's heart failure patients. Although the mechanisms driving cardiotoxicity are complex, cellular senescence is gaining attention as a major contributor to chemotherapy-induced cardiotoxicity and, therefore, may also represent a novel therapeutic target to prevent this disease. Cellular senescence is a well-recognized response to clinical doses of chemotherapies, including anthracyclines, and is defined by cell cycle exit, phenotypic alterations which include mitochondrial dysfunction, and the expression of the pro-senescent, pro-fibrotic, and pro-inflammatory senescence-associated phenotype. Senescence has an established involvement in promoting myocardial remodeling during aging, and studies have demonstrated that the elimination of senescence can attenuate the pathophysiology of several cardiovascular diseases. Most recently, pharmacology-mediated elimination of senescence, using a class of drugs termed senolytics, has been demonstrated to prevent myocardial dysfunction in preclinical models of chemotherapy-induced cardiotoxicity. In this review, we will discuss the evidence that anthracycline-induced senescence causes the long-term cardiotoxicity of anticancer chemotherapies, consider how the senescent phenotype may promote myocardial dysfunction, and examine the exciting possibility that targeting senescence may prove a therapeutic strategy to prevent or even reverse chemotherapy-induced cardiac dysfunction.

The effect of metformin on cardiovascular markers in female mice consuming a high fat diet

BACKGROUND

Metformin, widely used to treat diabetes, is now considered a candidate therapeutic for treatment of cardiovascular disease. This study aimed to assess whether metformin's non-glycaemic effects could mitigate cardiovascular disease indices in female mice consuming a high fat diet (HFD).

METHODS

Four-week old female Arc:Arc(S) mice were placed on a standard (std) chow diet or Western-style HFD (22% fat, 0.15% cholesterol). At ∼8 months, the mice were administered 150 mg/kg metformin or vehicle (control) via intraperitoneal injection for 11 days. Blood pressure was measured (tail cuff plethysmography) at Day 9 and 11 of treatment. On Day 11, mice were weighed and culled. The mesenteric arcade and kidneys were collected for assessment of vascular reactivity (wire myography), and assessment of expression of cardiometabolic markers (qPCR), respectively.

RESULTS

The HFD fed female mice were significantly heavier than those receiving the std diet at 1-12 weeks on diet, and at cull. Mice on a std diet with metformin treatment were significantly heavier at cull than the mice on a std diet administered the control treatment. Metformin treatment did not alter the weight of the mice receiving the HFD. Neither the HFD (compared to the std diet), nor metformin treatment (compared to control treatment) altered blood pressure, vascular reactivity, or expression of cardiometabolic markers in the kidney.

CONCLUSION

Consumption of a Western-style HFD (without high salt/sugar levels) did not alter the cardiovascular markers measured. Further studies are required to establish the non-glycaemic, cardio-protective effects of metformin in high-risk cohorts.

Relationship between metformin use and lactic acidosis in advanced chronic kidney disease: The REMIND-TMU study

BACKGROUND

Evidence of metformin-associated lactic acidosis (MALA) in advanced chronic kidney disease (CKD) has been limited due to high mortality rate but rare incidence rate. The mechanism of increased MALA in advanced CKD is mainly based on the hypothesis of decreased drug elimination, which might also be confounded by increased comorbidities as CKD progresses. The goal of the study is to analyze the incidence and associated factors of lactic acidosis between metformin user and non-user with advanced CKD.

METHODS

This study used a three million population-based, propensity score-matched cohort from 2008 to 2016. The primary outcome was laboratory-defined lactic acidosis. Relationships between the probability of lactic acidosis and various estimated glomerular filtration rate (eGFR) values in advanced CKD patients were also presented in regression analysis.

RESULTS

Adults with type 2 diabetes whose eGFR was <30 mL/min/1.73 m² were enrolled in this study. After the process of propensity score matching, 7707 patients were divided into metformin and non-metformin groups. In linear regression model, metformin significantly increased the risk of lactic acidosis (p=0.0204) as the eGFR declined in advanced CKD over a mean follow up of over 600 days even after confounder adjustment with age, sex and comorbidities.

CONCLUSIONS

Metformin was associated with a significant increased risk of laboratory-defined lactic acidosis (p=0.0204) even after adjusting confounder such as age, sex and underlying comorbidities. This "REMIND" study reminds us that metformin-associated lactic acidosis is mainly caused by decreased drug renal elimination other than underlying comorbidities in advanced CKD patients.

Metformin: Activation of 5′ AMP-activated protein kinase and its emerging potential beyond anti-hyperglycemic action

Metformin is a plant-based drug belonging to the class of biguanides and is known to treat type-2 diabetes mellitus (T2DM). The drug, combined with controlling blood glucose levels, improves the body’s response to insulin. In addition, trials have identified the cardioprotective potential of metformin in the diabetic population receiving the drug. Activation of 5′ AMP-activated protein kinase (AMPK) is the major pathway for these potential beneficial effects of metformin. Historically, much emphasis has been placed on the potential indications of metformin beyond its anti-diabetic use. This review aims to appraise other potential uses of metformin primarily mediated by the activation of AMPK. We also discuss various mechanisms, other than AMPK activation, by which metformin could produce beneficial effects for different conditions. Databases including PubMed/MEDLINE and Embase were searched for literature relevant to the review’s objective. Reports from both research and review articles were considered. We found that metformin has diverse effects on the human body systems. It has been shown to exert anti-inflammatory, antioxidant, cardioprotective, metabolic, neuroprotective, anti-cancer, and antimicrobial effects and has now even been identified as effective against SARS-CoV-2. Above all, the AMPK pathway has been recognized as responsible for metformin’s efficiency and effectiveness. Owing to its extensive potential, it has the capability to become a part of treatment regimens for diseases apart from T2DM.

Using Computational Drug-Gene Analysis to Identify Novel Therapeutic Candidates for Retinal Neuroprotection

Retinal cell death is responsible for irreversible vision loss in many retinal disorders. No commercially approved treatments are currently available to attenuate retinal cell loss and preserve vision. We seek to identify chemicals/drugs with thoroughly-studied biological functions that possess neuroprotective effects in the retina using a computational bioinformatics approach. We queried the National Center for Biotechnology Information (NCBI) to identify genes associated with retinal neuroprotection. Enrichment analysis was performed using ToppGene to identify compounds related to the identified genes. This analysis constructs a Pharmacome from multiple drug-gene interaction databases to predict compounds with statistically significant associations to genes involved in retinal neuroprotection. Compounds with known deleterious effects (e.g., asbestos, ethanol) or with no clinical indications (e.g., paraquat, ozone) were manually filtered. We identified numerous drug/chemical classes associated to multiple genes implicated in retinal neuroprotection using a systematic computational approach. Anti-diabetics, lipid-lowering medicines, and antioxidants are among the treatments anticipated by this analysis, and many of these drugs could be readily repurposed for retinal neuroprotection. Our technique serves as an unbiased tool that can be utilized in the future to lead focused preclinical and clinical investigations for complex processes such as neuroprotection, as well as a wide range of other ocular pathologies.

Examining the relationship between metformin dose and cancer survival: A SEER-Medicare analysis

Cancer is a major health problem in the U.S and type 2 diabetes mellitus (T2DM) is known to increase the risk for the development of many cancers. Metformin, a first-line therapy for treating T2DM, is increasingly being used for its anticancer effects; however, the literature is limited on the effect of metformin dose on overall survival in patients with stage IV cancer. Overall survival was defined as the time interval from the date of diagnosis to the last known follow-up or death from any cause. Subjects who were alive on December 31, 2016 were censored. In this cohort study we examined the relationship between metformin dose and overall survival in persons with both T2DM and stage IV lung, breast, colorectal, prostate, or pancreas cancers. We used a retrospective study design with Cox proportional hazards regression analysis of the 2007-2016 of the Surveillance Epidemiology and End Results-Medicare (SEER) dataset. Of the 7,725 patients, 2,981(38.5%) had been prescribed metformin. Patients who used metformin had significantly better overall survival in both unadjusted (Unadjusted HR, 0.73; 95% CI, 0.69-0.76; p < 0.001) and adjusted models (adjusted HR, 0.77; 95% CI, 0.73-0.81; p < 0.001). The overall survival between patients who took metformin with average daily dose ≥ 1000mg or < 1000mg were not statistically significant (aHR, 1.00; 95% CI, 0.93-1.08; p = 0.90). Metformin use regardless of dose is associated with increased overall survival in older adults with stage IV cancer.

Metformin's Impact on the Microvascular Response to Insulin

Metformin improves insulin's action on whole-body glucose metabolism in various insulin-resistant populations. The detailed cellular mechanism(s) for its metabolic actions are multiple and still incompletely understood. Beyond metabolic actions, metformin also impacts microvascular function. However, the effects of metformin on microvascular function and microvascular insulin action specifically are poorly defined. In this mini-review, we summarize what is currently known about metformin's beneficial impact on both microvascular function and the microvascular response to insulin while highlighting methodologic issues in the literature that limit straightforward mechanistic understanding of these effects. We examine potential mechanisms for these effects based on pharmacologically dosed studies and propose that metformin may improve human microvascular insulin resistance by attenuating oxidative stress, inflammation, and endothelial dysfunction. Finally, we explore several important evidence gaps and discuss avenues for future investigation that may clarify whether metformin's ability to improve microvascular insulin sensitivity is linked to its positive impact on vascular outcomes.

Interactions of Autophagy and the Immune System in Health and Diseases

Autophagy is a highly conserved process that utilizes lysosomes to selectively degrade a variety of intracellular cargo, thus providing quality control over cellular components and maintaining cellular regulatory functions. Autophagy is triggered by multiple stimuli ranging from nutrient starvation to microbial infection. Autophagy extensively shapes and modulates the inflammatory response, the concerted action of immune cells, and secreted mediators aimed to eradicate a microbial infection or to heal sterile tissue damage. Here, we first review how autophagy affects innate immune signaling, cell-autonomous immune defense, and adaptive immunity. Then, we discuss the role of non-canonical autophagy in microbial infections and inflammation. Finally, we review how crosstalk between autophagy and inflammation influences infectious, metabolic, and autoimmune disorders.

Changing Patterns of Antihyperglycaemic Treatment among Patients with Type 2 Diabetes in Hungary between 2015 and 2020-Nationwide Data from a Register-Based Analysis

Background and objectives: In the last couple of years, pharmacological management of patients with type 2 diabetes mellitus (T2DM) have been markedly renewed. The aim of this study was to analyse the changes in prescribing patterns of antidiabetic drugs for treating patients with T2DM in Hungary between 2015 and 2020. Material and Methods: In this retrospective, nationwide analysis, we used the central database of the National Health Insurance Fund. We present annual numbers and their proportion of T2DM patients with different treatment regimens. Results: In the period of 2015−2020, the number of incident cases decreased from 60,049 to 29,865, while prevalent cases increased from 682,274 to 752,367. Patients with metformin (MET) monotherapy had the highest prevalence (31% in 2020). Prevalence of insulin (INS) monotherapy continuously but slightly decreased from 29% to 27% while that of sulfonylurea (SU) monotherapy markedly decreased from 37% to 20%. Dipeptidyl peptidase (DPP-4) inhibitors remained popular in 2020 as monotherapy (5%), in dual combination with MET (12%) and in triple combination with MET and SU (5%). The prevalence of patients with sodium-glucose co-transporter-2 (SGLT-2) inhibitors increased from 1% to 4% in monotherapy, from <1% to 6% in dual combination with MET, and from <1% to 2% in triple oral combination with MET and SU or DPP-4-inhibitors. The prevalence of patients using glucagon-like peptide-1 receptor agonists (GLP-1-RAs) also increased but remained around 1−2% both in monotherapy and combinations. For initiating antihyperglycaemic treatment, MET monotherapy was the most frequently used regime in 2020 (50%), followed by monotherapy with SUs (16%) or INS (10%). After initial MET monotherapy, the incidence rates of patients with add-on GLP-1-RAs (2%, 3%, and 4%) and those of add-on SGLT-2 inhibitors (4%, 6%, and 8%) slowly increased in the subsequent 24, 48, and 72 months, respectively. Conclusions: In the period of 2015−2020, we documented important changes in trends of antihyperglycaemic therapeutic patterns in patients with T2DM which followed the new scientific recommendations but remained below our expectations regarding timing and magnitude. More efforts are warranted to implement new agents with cardiovascular/renal benefits into therapeutic management in time, in a much larger proportion of T2DM population, and without delay.

[Cardiovascular preventive recommendations. PAPPS 2022 thematic updates. Working groups of the PAPPS]

The recommendations of the semFYC's Program for Preventive Activities and Health Promotion (PAPPS) for the prevention of cardiovascular diseases (CVD) are presented. The following sections are included: epidemiological review, where the current morbidity and mortality of CVD in Spain and its evolution as well as the main risk factors are described; cardiovascular (CV) risk and recommendations for the calculation of CV risk; main risk factors such as arterial hypertension, dyslipidemia and diabetes mellitus, describing the method for their diagnosis, therapeutic objectives and recommendations for lifestyle measures and pharmacological treatment; indications for antiplatelet therapy, and recommendations for screening of atrial fibrillation, and recommendations for management of chronic conditions. The quality of testing and the strength of the recommendation are included in the main recommendations.

Effect of metformin on adverse outcomes in T2DM patients: Systemic review and meta-analysis of observational studies

Background

The cardiovascular protection effect of metformin on patients with type 2 diabetes mellitus (T2DM) remains inconclusive. This systemic review and meta-analysis were to estimate the effect of metformin on mortality and cardiovascular events among patients with T2DM.

Methods

A search of the Pubmed and EMBASE databases up to December 2021 was performed. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were pooled by a random-effects model with an inverse variance method.

Results

A total of 39 studies involving 2473009 T2DM patients were adopted. Compared to non-metformin therapy, the use of metformin was not significantly associated with a reduced risk of major adverse cardiovascular event (MACE) (HR = 1.06, 95%CI 0.91–1.22; I² = 82%), hospitalization (HR = 0.85, 95%CI 0.64–1.13; I² = 98%), heart failure (HR = 0.86, 95%CI 0.60–1.25; I² = 99%), stroke (HR = 1.16, 95%CI 0.88–1.53; I² = 84%), and risk of AMI (HR = 0.88, 95%CI 0.69–1.14; I² = 88%) in T2DM patients. Metformin was also not associated with significantly lowered risk of MACE compared to dipeptidyl peptidase-4 inhibitor (DPP-4i) in T2DM patients (HR = 0.95, 95%CI 0.73–1.23; I² = 84%).

Conclusions

The effect of metformin on some cardiovascular outcomes was not significantly better than the non-metformin therapy or DPP-4i in T2DM patients based on observational studies.

Attenuated Risk Association of End-Stage Kidney Disease with Metformin in Type 2 Diabetes with eGFR Categories 1-4

Type 2 diabetes (T2D)-associated end-stage kidney disease (ESKD) is a global burden, while the renoprotective effects of metformin remain controversial. In a population-based cohort (2002-2018) including 96,643 patients with T2D observed for 0.7 million person-years, we estimated the risk association of metformin and its dose-relationship with ESKD in a propensity-score overlap-weighting (PS-OW) cohort by eGFR categories. Amongst 96,643, 83,881 (86.8%) had eGFR-G1/G2 (≥60 mL/min/1.73 m2), 8762 (9.1%) had eGFR-G3a (≥45-60 mL/min/1.73 m2), 3051 (3.2%) had eGFR-G3b (≥30-45 mL/min/1.73 m2), and 949 (1.0%) had eGFR-G4 (≥15-30 mL/min/1.73 m2). The respective proportions of metformin users in these eGFR categories were 95.1%, 81.9%, 53.8%, and 20.8%. In the PS-OW cohort with 88,771 new-metformin and 7872 other oral glucose-lowering-drugs (OGLDs) users, the respective incidence rates of ESKD were 2.8 versus 22.4/1000 person-years. Metformin use associated with reduced risk of ESKD (hazard ratio (HR) = 0.43 [95% CI: 0.35-0.52] in eGFR-G1/G2, 0.64 [0.52-0.79] in eGFR-G3a, 0.67 [0.56-0.80] in eGFR-G3b, and 0.63 [0.48-0.83] in eGFR-G4). Metformin use was associated with reduced or neutral risk of major adverse cardiovascular events (MACE) (7.2 versus 16.0/1000 person-years) and all-cause mortality (14.6 versus 65.1/1000 person-years). Time-weighted mean daily metformin dose was 1000 mg in eGFR-G1/G2, 850 mg in eGFR-G3a, 650 mg in eGFR-G3b, and 500 mg in eGFR-G4. In a subcohort of 14,766 patients observed for 0.1 million person-years, the respective incidence rates of lactic acidosis and HR in metformin users and non-users were 42.5 versus 226.4 events/100,000 person-years (p = 0.03) for eGFR-G1/G2 (HR = 0.57, 0.25-1.30) and 54.5 versus 300.6 events/100,000 person-years (p = 0.01) for eGFR-G3/G4 (HR = 0.49, 0.19-1.30). These real-world data underscore the major benefits and low risk of lactic acidosis with metformin use down to an eGFR of 30 mL/min/1.73 m2 and possibly even 15 mL/min/1.73 m2, while reinforcing the importance of dose adjustment and frequent monitoring of eGFR.

Effect of metformin on left ventricular mass and functional parameters in non-diabetic patients: a meta-analysis of randomized clinical trials

BACKGROUND

Left ventricular hypertrophy is a common finding in patients with ischemic heart disease and is associated with mortality in patients with cardiovascular disease (CVD). Metformin, an antidiabetic drug, has been shown to reduce oxidative stress and left ventricular mass index (LVMI) in animal hypertrophy models. We summarized evidence regarding the effect of metformin on LVMI and LVEF.

METHODS

Electronic databases were searched for randomized clinical trials (RCTs) that used metformin in non-diabetic patients with or without pre-existing CVD. The standardized mean change using change score standardization (SMCC) was calculated for each study. The random-effects model was used to pool the SMCC across studies. Meta-regression analysis was used to assess the association of heart failure (HF), metformin dose, and duration with the SMCC.

RESULTS

Data synthesis from nine RCTs (754 patients) showed that metformin use resulted in higher reduction in LVMI after 12 months (SMCC = -0.63, 95% CI - 1.23; - 0.04, p = 0.04) and an overall higher reduction in LVMI (SMCC = -0.5, 95% CI - 0.84; - 0.16, p < 0.01). These values equate to absolute values of 11.3 (95% CI 22.1-0.72) and 8.97 (95% CI 15.06-2.87) g/m2, respectively. The overall improvement in LVEF was also higher in metformin users after excluding one outlier (SMCC = 0.26, 95% CI 0.03-0.49, P = 0.03) which translates to a higher absolute improvement of 2.99% (95% CI 0.34; 5.63). Subgroup analysis revealed a favorable effect for metformin on LVEF in patients who received > 1000 mg/day (SMCC = 0.28, 95% CI 0.04; 0.52, P = 0.04), and patients with HF (SMCC = 0.23; 95% CI 0.1; 0.36; P = 0.004). These values translate to a higher increase of 2.64% and 3.21%, respectively.

CONCLUSION

Results suggest a favorable effect for metformin on LVMI and LVEF in patients with or without pre-existing CVD. Additional trials are needed to address the long-term effect of metformin. Registration The study was registered on the PROSPERO database with the registration number CRD42021239368 ( https://www.crd.york.ac.uk/prospero ).

Anti-obesity therapy for cardiovascular disease prevention: potential expected roles of glucagon-like peptide-1 receptor agonists

Obesity is characterized by visceral fat accumulation and various metabolic disturbances that cause metabolic syndrome and obesity-related cardiovascular diseases (ORCVDs). Hence, treatments targeting obesity should also prevent ORCVDs. Nonetheless, lifestyle modification therapy alone is still insufficient to reduce the risk of ORCVDs, although most cardiovascular guidelines still list it as the only treatment for obesity. Additionally, conventional anti-obesity drugs, such as orlistat, phentermine-topiramate, and naltrexone-bupropion, can reduce body weight but have not demonstrated a clear reduction in the risk of ORCVDs. To overcome this unmet clinical need, newer anti-obesity drugs must exhibit not only sufficient and long-lasting weight loss but also obvious cardiovascular benefits. Given recent clinical findings and evidences, in this context glucagon-like peptide-1 receptor agonist is currently available as a candidate that is clinically positioned as a first-line anti-obesity agent for the effective prevention of ORCVDs in people with obesity.

Emerging role of neutrophil extracellular traps in the complications of diabetes mellitus

Immune dysfunction is widely regarded as one of the central tenants underpinning the pathophysiology of diabetes mellitus (DM) and its complications. When discussing immunity, the role of neutrophils must be accounted for: neutrophils are the most abundant of the circulating immune cells and are the first to be recruited to sites of inflammation, where they contribute to host defense via phagocytosis, degranulation, and extrusion of neutrophil extracellular traps (NETs). NETs are composed of DNA associated with nuclear and cytosolic neutrophil proteins. Although originally reported as an antimicrobial strategy to prevent microbial dissemination, a growing body of evidence has implicated NETs in the pathophysiology of various autoimmune and metabolic disorders. In these disorders, NETs propagate a pathologic inflammatory response with consequent tissue injury and thrombosis. Many diabetic complications—such as stroke, retinopathy, impaired wound healing, and coronary artery disease—involve these mechanisms. Therefore, in this review, we discuss laboratory and clinical data informing our understanding of the role of NETs in the development of these complications. NET markers, including myeloperoxidase, citrullinated histone H3, neutrophil elastase, and cell-free double-stranded DNA, can easily be measured in serum or be detected via immunohistochemical/immunocytochemical staining of tissue specimens. Therefore, NET constituents potentially constitute reliable biomarkers for use in the management of diabetic patients. However, no NET-targeting drug is currently approved for the treatment of diabetic complications; a candidate drug will require the outcomes of well-designed, robust clinical trials assessing whether NET inhibition can benefit patients in terms of morbidity, quality of life, health expenditures, and mortality. Therefore, much work remains to be done in translating these encouraging pieces of data into clinical trials for NET-targeting medications to be used in the clinic.

Multimorbidity and combined interventions for patients with coronary heart disease in Chinese population: Latent class analysis of a multi-center study

BACKGROUND AND AIMS

This study aimed to explore the profile of multimorbidity phenotype clusters and their discrepancy in mortality and the efficiency of combined interventions on blood pressure, glucose and lipid in each cluster.

METHODS

Fine and Gray competing risk regression models and Kaplan-Meier curves were used to assess the association between multimorbidity and mortality and rehospitalization. Fine and Gray competing risk regression models and subgroup analyses were used to estimate the relations between combined interventions and mortality.

RESULTS

Three distinct multimorbidity clusters were observed: Class 1 named severe class, Class 2 termed moderate class, and Class 3 named mild class. Competing risk regression models revealed that patients in Class 1 have the greatest burden of mortality and rehospitalization compared to Class 3 after confounder adjustment, with HRs 1.43 (95% CI 1.30-1.56, P < 0.001) and 2.97 (95% CI 2.74-3.21, P < 0.001), respectively. The patients in Class 2 have moderate risk of mortality and rehospitalization compared to Class 3 after confounder adjustment, with HRs 1.41 (95% CI 1.30-1.52, P < 0.001) and 2.39 (95% CI 2.23-2.56, P < 0.001), respectively. Furthermore, we found that combined interventions on blood pressure, glucose and lipid simultaneously could further benefit on survival compared to each individual intervention or two in combine.

CONCLUSIONS

This study found that multimorbidity among patients with CHD was common and increased the risks of death and rehospitalization. Three multimorbidity clusters that were significantly associated with death and rehospitalization were identified. Simultaneous intervention on blood pressure, glucose and lipid level may further benefit CHD patient in survival.