Metformin to decrease COVID-19 severity and mortality: Molecular mechanisms and therapeutic potential

Metformin's anticancer odyssey: Revealing multifaceted mechanisms across diverse neoplastic terrains- a critical review

Metformin, initially prescribed as an oral hypoglycemic medication for type 2 diabetes, has recently gained attention for its potential anticancer effects. Its history dates to 1918, when guanidine, a component of the traditional European herb Galega officinalis, was found to reduce glycemia. This review precisely examines the mechanisms underlying Metformin's anticancer effects across various neoplastic conditions. This investigation explores the complex interactions between metformin and major signaling pathways associated with carcinogenesis, including AMP-activated protein kinase (AMPK), mTOR, and insulin-like growth factor (IGF) pathways. The review emphasizes Metformin's diverse effects on angiogenesis, inflammation, apoptosis, and cellular metabolism in cancer cells. Additionally, new data on metformin's capacity to alter the tumor microenvironment and enhance immune surveillance systems against cancer are examined. The review underscores Metformin's potential for repurposing in oncology, emphasizing its clinical relevance as an adjuvant therapy for various cancers. The review provides insightful information about the complex anticancer mechanisms of metformin by combining data from preclinical and clinical studies. These findings not only broaden our knowledge of the effects of metformin but also open new avenues for oncology research and treatment developments.

Unlocking the gut-liver axis: microbial contributions to the pathogenesis of metabolic-associated fatty liver disease

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a complex metabolic disorder characterized by hepatic lipid accumulation and subsequent inflammation. This condition is closely linked to metabolic syndrome and obesity, with its prevalence rising due to sedentary lifestyles and high-calorie diets. The pathogenesis of MAFLD involves multiple factors, including insulin resistance, lipotoxicity, oxidative stress, and inflammatory responses. The gut microbiota plays a crucial role in MAFLD development, with dysbiosis contributing to liver inflammation through various mechanisms, such as enhanced intestinal permeability and the translocation of bacterial products like lipopolysaccharide (LPS). Microbial metabolites, including short-chain fatty acids (SCFAs) and bile acids, influence hepatic function and immune responses, with potential implications for disease progression. Specific gut microbiome signatures have been identified in MAFLD patients, offering potential diagnostic and therapeutic targets. Moreover, gut-derived toxins, such as endotoxins, lipopolysaccharides, trimethylamine-N-oxide and bacterial metabolites, significantly influence liver damage and inflammation, highlighting the complex interplay between the gut microbiome and hepatic health. This review comprehensively examines the complex interplay between the gut microbiota and MAFLD, focusing on underlying pathogenic mechanisms, potential biomarkers, and emerging microbiome-targeted therapeutic strategies for disease management.

Involvement of metformin and aging in salivary expression of ACE2 and TMPRSS2

SARS-CoV-2-related proteins, ACE2 and TMPRSS2, are determinants of SARS-CoV-2 infection. Although these proteins are expressed in oral-related tissues, their expression patterns and modulatory mechanisms in the salivary glands remain unknown. We herein showed that full-length ACE2, which has both a fully functional enzyme catalytic site and high-affinity SARS-CoV-2 spike S1-binding sites, was more highly expressed in salivary glands than in oral mucosal epithelial cells and the lungs. Regarding TMPRSS2, zymogen and the cleaved form were both expressed in the salivary glands, whereas only zymogen was expressed in murine lacrimal glands and the lungs. Metformin, an AMPK activator, increased stimulated saliva secretion and full-length ACE2 expression and decreased cleaved TMPRSS2 expression in the salivary glands, and exerted the same effects on soluble ACE2 (sACE2) and sTMPRSS2 in saliva. Moreover, metformin decreased the expression of beta-galactosidase, a senescence marker, and ADAM17, a sheddase of ACE2 to sACE2, in the salivary glands. In aged mice, the expression of ACE2 was decreased in the salivary glands, whereas that of sACE2 was increased in saliva, presumably by the up-regulated expression of ADAM17. The expression of TMPRSS2 in the salivary glands and sTMPRSS2 in saliva were both increased. Collectively, these results suggest that the protein expression patterns of ACE2 and TMPRSS2 in the salivary glands differ from those in other oral-related cells and tissues, and also that metformin and aging affect the salivary expression of ACE2 and TMPRSS2, which have the potential as targets for preventing the transmission of SARS-CoV-2.

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.

AMP kinase: A promising therapeutic drug target for post-COVID-19 complications

The COVID-19 pandemic, caused by SARS-CoV-2, has resulted in severe respiratory issues and persistent complications, particularly affecting glucose metabolism. Patients with or without pre-existing diabetes often experience worsened symptoms, highlighting the need for innovative therapeutic approaches. AMPK, a crucial regulator of cellular energy balance, plays a pivotal role in glucose metabolism, insulin sensitivity, and inflammatory responses. AMPK activation, through allosteric or kinase-dependent mechanisms, impacts cellular processes like glucose uptake, fatty acid oxidation, and autophagy. The tissue-specific distribution of AMPK emphasizes its role in maintaining metabolic homeostasis throughout the body. Intriguingly, SARS-CoV-2 infection inhibits AMPK, contributing to metabolic dysregulation and post-COVID-19 complications. AMPK activators like capsaicinoids, curcumin, phytoestrogens, cilostazol, and momordicosides have demonstrated the potential to regulate AMPK activity. Compounds from various sources improve fatty acid oxidation and insulin sensitivity, with metformin showing opposing effects on AMPK activation compared to the virus, suggesting potential therapeutic options. The diverse effects of AMPK activation extend to its role in countering viral infections, further highlighting its significance in COVID-19. This review explores AMPK activation mechanisms, its role in metabolic disorders, and the potential use of natural compounds to target AMPK for post-COVID-19 complications. Also, it aims to review the possible methods of activating AMPK to prevent post-COVID-19 diabetes and cardiovascular complications. It also explores the use of natural compounds for their therapeutic effects in targeting the AMPK pathways. Targeting AMPK activation emerges as a promising avenue to mitigate the long-term effects of COVID-19, offering hope for improved patient outcomes and a better quality of life.

Metformin use and its association with various outcomes in COVID-19 patients with diabetes mellitus: a retrospective cohort study in a tertiary care facility

BACKGROUND

Evidence shows that diabetes raises the probability of contracting COVID-19 and associated complications. We hypothesize that metformin, being pleiotropic, may improve COVID-19 in diabetics.

METHODS

A retrospective cohort study was conducted with 421 COVID-19 patients with diabetes, hospitalized between 1st April 2020 and 31st March 2022 in a tertiary-care hospital. Patients with metformin or its combination constituted the study cohort (SC; n = 221), while other antidiabetics constituted the reference cohort (RC; n = 200).

RESULTS

SC and RC were matched for mean age ± SD (SC: 53.3 ± 5.7 vs. RC: 54.3 ± 8.2 years). The mean length of hospitalization (days) was significantly shorter in SC (9.0 ± 5.7) than in RC (12.7 ± 6) (p < 0.02). Metformin use was associated with reduction in mortality risk (OR: 0.106, 95% CI = 0.039-0.287; p < 0.001). Moreover, SC also improved levels of LDH (OR: 0.243, 95% CI = 0.104-0.566; p < 0.001), CRP (OR: 0.281, 95% CI = 0.120-0.659; p < 0.004), and D-dimer (OR: 0.220, 95% CI = 0.089-0.539; p < 0.001) than RC. The calculated number needed to treat for metformin was 3.1.

CONCLUSION

Metformin users have a decrease in hospital stay and mortality rates and improvement in LDH, CRP, and D-dimer levels. Therefore, metformin might protect against mortality in COVID-19 with diabetes.

Exploring the Efficacy of Alpha-Lipoic Acid in Comorbid Osteoarthritis and Type 2 Diabetes Mellitus

Background/Objectives. The comorbidity of osteoarthritis and type 2 diabetes mellitus poses a complex clinical challenge, complicating patient management due to overlapping pathophysiological mechanisms. This research aims to analyze the exacerbation of clinical symptoms and biochemical markers in patients with OA and T2DM compared to those with OA alone. Methods. We employed various assessment methods to evaluate inflammation, oxidative stress, and glycemic control in both cohorts. This study includes the administration of alpha-lipoic acid (ALA) to patients with comorbid OA and T2DM, monitoring its effects on joint function, inflammatory markers, oxidative stress levels, and glycemic control. Results. The findings indicate that T2DM significantly worsens clinical symptoms and biochemical markers in OA patients. Those with both conditions exhibited elevated indicators of inflammation and oxidative stress compared to OA-only patients. Additionally, correlations among metabolic, psychological, and inflammatory factors were identified. Body mass index emerged as a potential predictor for the deterioration of evaluated parameters. The analysis revealed that ALA administration led to statistically significant improvements in WOMAC pain scores, the Lequesne Algofunctional Index, and the AIMS-P compared to the control group. Conclusions. Further research into ALA's effects on OA progression in patients with comorbidities is essential for developing personalized treatment approaches.

Targeting senescent cells in aging and COVID-19: from cellular mechanisms to therapeutic opportunities

The COVID-19 pandemic has caused a global health crisis and significant social economic burden. While most individuals experience mild or non-specific symptoms, elderly individuals are at a higher risk of developing severe symptoms and life-threatening complications. Exploring the key factors associated with clinical severity highlights that key characteristics of aging, such as cellular senescence, immune dysregulation, metabolic alterations, and impaired regenerative potential, contribute to disruption of tissue homeostasis of the lung and worse clinical outcome. Senolytic and senomorphic drugs, which are anti-aging treatments designed to eliminate senescent cells or decrease the associated phenotypes, have shown promise in alleviating age-related dysfunctions and offer a novel approach to treating diseases that share certain aspects of underlying mechanisms with aging, including COVID-19. This review summarizes the current understanding of aging in COVID-19 progression, and highlights recent findings on anti-aging drugs that could be repurposed for COVID-19 treatment to complement existing therapies.

Genomic insight into COVID-19 severity in MAFLD patients: a single-center prospective cohort study

This study investigated the influence of single nucleotide polymorphisms (SNPs) in genes associated with the interferon pathway (IFNAR2 rs2236757), antiviral response (OAS1 rs10774671, OAS3 rs10735079), and viral entry (ACE2 rs2074192) on COVID-19 severity and their association with nonalcoholic fatty liver disease (MAFLD). We did not observe a significant association between the investigated SNPs and COVID-19 severity. While the IFNAR2 rs2236757 A allele was correlated with higher creatinine levels upon admission and the G allele was correlated with lower band neutrophils upon discharge, these findings require further investigation. The distribution of OAS gene polymorphisms (rs10774671 and rs10735079) did not differ between MAFLD patients and non-MAFLD patients. Our study population's distribution of ACE2 rs2074192 genotypes and alleles differed from that of the European reference population. Overall, our findings suggest that these specific SNPs may not be major contributors to COVID-19 severity in our patient population, highlighting the potential role of other genetic factors and environmental influences.

Diabetes and Osteoarthritis: Exploring the Interactions and Therapeutic Implications of Insulin, Metformin, and GLP-1-Based Interventions

Diabetes mellitus (DM) and osteoarthritis (OA) are prevalent chronic conditions with shared pathophysiological links, including inflammation and metabolic dysregulation. This study investigates the potential impact of insulin, metformin, and GLP-1-based therapies on OA progression. Methods involved a literature review of clinical trials and mechanistic studies exploring the effects of these medications on OA outcomes. Results indicate that insulin, beyond its role in glycemic control, may modulate inflammatory pathways relevant to OA, potentially influencing joint health. Metformin, recognized for its anti-inflammatory properties via AMPK activation, shows promise in mitigating OA progression by preserving cartilage integrity and reducing inflammatory markers. GLP-1-based therapies, known for enhancing insulin secretion and improving metabolic profiles in DM, also exhibit anti-inflammatory effects that may benefit OA by suppressing cytokine-mediated joint inflammation and supporting cartilage repair mechanisms. Conclusions suggest that these medications, while primarily indicated for diabetes management, hold therapeutic potential in OA by targeting common underlying mechanisms. Further clinical trials are warranted to validate these findings and explore optimal therapeutic strategies for managing both DM and OA comorbidities effectively.

Metformin Mitigates Sepsis-Induced Acute Lung Injury and Inflammation in Young Mice by Suppressing the S100A8/A9-NLRP3-IL-1β Signaling Pathway

Background

Globally, the subsequent complications that accompany sepsis result in remarkable morbidity and mortality rates. The lung is among the vulnerable organs that incur the sepsis-linked inflammatory storm and frequently culminates into ARDS/ALI. The metformin-prescribed anti-diabetic drug has been revealed with anti-inflammatory effects in sepsis, but the underlying mechanisms remain unclear. This study aimed to ascertain metformin's effects and functions in a young mouse model of sepsis-induced ALI.

Methods

Mice were randomly divided into 4 groups: sham, sham+ Met, CLP, and CLP+ Met. CLP was established as the sepsis-induced ALI model accompanied by intraperitoneal metformin treatment. At day 7, the survival state of mice was noted, including survival rate, weight, and M-CASS. Lung histological pathology and injury scores were determined by hematoxylin-eosin staining. The pulmonary coefficient was used to evaluate pulmonary edema. Furthermore, IL-1β, CCL3, CXCL11, S100A8, S100A9 and NLRP3 expression in tissues collected from lungs were determined by qPCR, IL-1β, IL-18, TNF-α by ELISA, caspase-1, ASC, NLRP3, P65, p-P65, GSDMD-F, GSDMD-N, IL-1β and S100A8/A9 by Western blot.

Results

The data affirmed that metformin enhanced the survival rate, lessened lung tissue injury, and diminished the expression of inflammatory factors in young mice with sepsis induced by CLP. In contrast to sham mice, the CLP mice were affirmed to manifest ALI-linked pathologies following CLP-induced sepsis. The expressions of pro-inflammatory factors, for instance, IL-1β, IL-18, TNF-α, CXCL11, S100A8, and S100A9 are markedly enhanced by CLP, while metformin abolished this adverse effect. Western blot analyses indicated that metformin inhibited the sepsis-induced activation of GSDMD and the upregulation of S100A8/A9, NLRP3, and ASC.

Conclusion

Metformin could improve the survival rate, lessen lung tissue injury, and minimize the expression of inflammatory factors in young mice with sepsis induced by CLP. Metformin reduced sepsis-induced ALI via inhibiting the NF-κB signaling pathway and inhibiting pyroptosis by the S100A8/A9-NLRP3-IL-1β pathway.

Anti-Inflammatory Potential of the Anti-Diabetic Drug Metformin in the Prevention of Inflammatory Complications and Infectious Diseases Including COVID-19: A Narrative Review

Metformin, a widely used first-line anti-diabetic therapy for the treatment of type-2 diabetes, has been shown to lower hyperglycemia levels in the blood by enhancing insulin actions. For several decades this drug has been used globally to successfully control hyperglycemia. Lactic acidosis has been shown to be a major adverse effect of metformin in some type-2 diabetic patients, but several studies suggest that it is a typically well-tolerated and safe drug in most patients. Further, recent studies also indicate its potential to reduce the symptoms associated with various inflammatory complications and infectious diseases including coronavirus disease 2019 (COVID-19). These studies suggest that besides diabetes, metformin could be used as an adjuvant drug to control inflammatory and infectious diseases. In this article, we discuss the current understanding of the role of the anti-diabetic drug metformin in the prevention of various inflammatory complications and infectious diseases in both diabetics and non-diabetics.

Frequency of Mortality and Adverse Outcomes of COVID-19 in Hospitalized Type 2 Diabetics with a History of Sitagliptin or Metformin Use

Background: The relationship between various blood glucose-lowering treatments for type 2 diabetes mellitus (T2DM) and the mortality and complication rates of COVID-19 infection holds significant relevance. Objectives: This retrospective study aimed to investigate the clinical progression of COVID-19 in T2DM patients previously treated with sitagliptin, metformin, or a combination of both. Methods: The study reviewed the medical records of T2DM patients with COVID-19 who had received treatment with sitagliptin, metformin, or both. Participants were selected from those admitted to Naft Hospital in Ahvaz, Iran, from March 2020 to March 2022. Data on mortality and adverse outcomes related to COVID-19 were gathered from the medical records. Results: The study included 529 diabetic patients treated with metformin (n = 197), sitagliptin (n = 231), or both (n = 101) for a minimum of three months. The overall mortality rate among diabetic patients was 15.1%, with the metformin group showing the highest mortality rate at 28.9% (P < 0.0001). Significant differences were observed among the three treatment groups in terms of the frequency of acute respiratory failure (P < 0.0001), stroke (P = 0.002), pulmonary embolism (P < 0.0001), and the necessity for ICU admission (P < 0.0001). Nonetheless, the incidence of myocardial infarction did not significantly differ between the groups. Conclusions: The findings suggest that sitagliptin use for blood sugar control in T2DM patients may help reduce adverse outcomes and the risk of death due to COVID-19. Mortality and morbidity rates were found to be higher in patients treated with metformin compared to those in the other groups.

Metformin Inhibits Zika Virus Infection in Trophoblast Cell Line

Zika virus (ZIKV) infections have been associated with severe clinical outcomes, which may include neurological manifestations, especially in newborns with intrauterine infection. However, licensed vaccines and specific antiviral agents are not yet available. Therefore, a safe and low-cost therapy is required, especially for pregnant women. In this regard, metformin, an FDA-approved drug used to treat gestational diabetes, has previously exhibited an anti-ZIKA effect in vitro in HUVEC cells by activating AMPK. In this study, we evaluated metformin treatment during ZIKV infection in vitro in a JEG3-permissive trophoblast cell line. Our results demonstrate that metformin affects viral replication and protein synthesis and reverses cytoskeletal changes promoted by ZIKV infection. In addition, it reduces lipid droplet formation, which is associated with lipogenic activation of infection. Taken together, our results indicate that metformin has potential as an antiviral agent against ZIKV infection in vitro in trophoblast cells.

Metformin Alters mRNA Expression of FOXP3, RORC, and TBX21 and Modulates Gut Microbiota in COVID-19 Patients with Type 2 Diabetes

COVID-19 remains a significant global concern, particularly for individuals with type 2 diabetes who face an elevated risk of hospitalization and mortality. Metformin, a primary treatment for type 2 diabetes, demonstrates promising pleiotropic properties that may substantially mitigate disease severity and expedite recovery. Our study of the gut microbiota and the mRNA expression of pro-inflammatory and anti-inflammatory T-lymphocyte subpopulations showed that metformin increases bacterial diversity while modulating gene expression related to T-lymphocytes. This study found that people who did not take metformin had a downregulated expression of FOXP3 by 6.62-fold, upregulated expression of RORC by 29.0-fold, and upregulated TBX21 by 1.78-fold, compared to the control group. On the other hand, metformin patients showed a 1.96-fold upregulation in FOXP3 expression compared to the control group, along with a 1.84-fold downregulation in RORC expression and an 11.4-fold downregulation in TBX21 expression. Additionally, we found a correlation with gut microbiota (F/B ratio and alpha-diversity index) and pro-inflammatory biomarkers. This novel observation of metformin's impact on T-cells and gut microbiota opens new horizons for further exploration through clinical trials to validate and confirm our data. The potential of metformin to modulate immune responses and enhance gut microbiota diversity suggests a promising avenue for therapeutic interventions in individuals with type 2 diabetes facing an increased risk of severe outcomes from COVID-19.

The role of SARS-CoV-2-mediated NF-κB activation in COVID-19 patients

The SARS-CoV-2 pandemic, now in its third year, has had a profound impact on public health and economics all over the world. Different populations showed varied susceptibility to this virus and mortality after infection. Clinical and laboratory data revealed that the uncontrolled inflammatory response plays an important role in their poor outcome. Herein, we summarized the role of NF-κB activation during SARS-CoV-2 invasion and replication, particularly the angiotensin-converting enzyme 2 (ACE2)-mediated NF-κB activation. Then we summarized the COVID-19 drugs' impact on NF-κB activation and their problems. A favorable prognosis is linked with timely treatment with NF-κB activation inhibitors, such as TNFα, IL-1β, and IL-6 monoclonal antibodies. However, further clinical researches are still required to clarify the time window, dosage of administration, contraindication, and potential side effects of these drugs, particularly for COVID-19 patients with hypertension, hyperglycemia, diabetes, or other chronic diseases.

Gene expression of protein kinase AMP-activated catalytic subunit alpha 1 (PRKAA1), solute carrier family 2 member 1 (SLC2A1) and mechanistic target of rapamycin (MTOR) in metformin-treated type 2 diabetes patients with COVID-19: impact on inflammation markers

The COVID-19 pandemic has resulted in a global health crisis that has severely impacted patients with type 2 diabetes (T2D). T2D patients have a higher risk of experiencing severe COVID-19 symptoms, hospitalization, and mortality compared to patients without diabetes. The dysregulated immune response in T2D patients can exacerbate the severity of COVID-19 symptoms. Insulin therapy, a common treatment for T2D patients, has been linked to increased mortality in COVID-19 patients with T2D. However, metformin, an anti-diabetic medication, has been shown to have anti-inflammatory properties that may mitigate the cytokine storm observed in severe COVID-19 cases. In this study, we investigated how the PRKAA1, SLC2A1, and MTOR genes contribute to inflammation markers in COVID-19 patients with T2D, who were receiving either insulin or metformin therapy. Our findings revealed that metformin treatment was associated with reduced expression of genes involved in Th1/Th17 cell differentiation. These results suggest that metformin could be a potential treatment option for T2D patients with COVID-19 due to its anti-inflammatory properties, which may improve patient outcomes.

Exploring Paxlovid Efficacy in COVID-19 Patients with MAFLD: Insights from a Single-Center Prospective Cohort Study

This study investigates the intricate interplay between Metabolic-associated Fatty Liver Disease (MAFLD) and COVID-19, exploring the impact of MAFLD on disease severity, outcomes, and the efficacy of the antiviral agent Paxlovid (nirmatrelvir/ritonavir). MAFLD, affecting a quarter of the global population, emerges as a potential risk factor for severe COVID-19, yet the underlying pathophysiological mechanisms remain elusive. This study focuses on the clinical significance of Paxlovid, the first orally bioavailable antiviral agent granted Emergency Use Authorization in the United States. Notably, outcomes from phase II/III trials exhibit an 88% relative risk reduction in COVID-19-associated hospitalization or mortality among high-risk patients. Despite conflicting data on the association between MAFLD and COVID-19 severity, this research strives to bridge the gap by evaluating the effectiveness of Paxlovid in MAFLD patients with COVID-19, addressing the scarcity of relevant studies.

Antidiabetic Drug Efficacy in Reduction of Mortality during the COVID-19 Pandemic

Background and Objectives: The COVID-19 pandemic caused by the Coronavirus SARS-CoV-2 is a complex challenge for the existing scientific and medical landscape. It is an ongoing public health crisis, with over 245,373,039 confirmed cases globally, including 4,979,421 deaths as of 29 October 2021. Exploring molecular mechanisms correlated with the disease's severity has demonstrated significant factors of immune compromise, noted in diabetic patients with SARS-CoV-2 infections. Among diabetics, the altered function of the immune system allows for better penetration of the virus into epithelial cells, increased viral binding affinity due to hyperglycemia, reduced T cell function, decreased viral clearance, high risks of cytokine storm, and hyper-inflammatory responses, altogether increasing the susceptibility of these patients to an extreme COVID-19 disease course. Materials and Methods: This research involved a systematic literature search among various databases comprising PubMed and Google Scholar in determining credible studies about the effects of antidiabetic drugs on the high mortality rates among diabetic patients infected with COVID-19. The primary search found 103 results. Duplicated results, non-pertinent articles, and the unavailability of full text were excluded. Finally, we included 74 articles in our review. The inclusion criteria included articles published during 2020-2023, studies that reported a low risk of bias, and articles published in English. Exclusion criteria included studies published in non-peer-reviewed sources, such as conference abstracts, thesis papers, or non-academic publications. Results: Among the studied anti-diabetic drugs, Metformin, the Glucagon-like peptide 1 receptor agonist (GLP-1RA), and Sodium-glucose co-transporter 2 inhibitors (SGLT-2i) have demonstrated decreased mortality rates among diabetic patients infected with COVID-19. Insulin and Dipeptidyl peptidase 4 inhibitors (DPP-4i) have demonstrated increased mortality rates, while Sulfonylureas, Thiazolidinedione (TZD), and Alpha-glucosidase inhibitors (AGI) have demonstrated mortality-neutral results.

Unveiling the potential pleiotropic effects of metformin in treating COVID-19: a comprehensive review

This review article explores the potential of metformin, a medication commonly used for type 2 diabetes, as an antiviral and anti-inflammatory agent in the context of coronavirus disease 2019 (COVID-19). Metformin has demonstrated inhibitory effects on the growth of SARS-CoV-2 in cell culture models and has shown promising results in reducing viral load and achieving undetectable viral levels in clinical trials. Additionally, metformin exhibits anti-inflammatory properties by reducing the production of pro-inflammatory cytokines and modulating immune cell function, which may help prevent cytokine storms associated with severe COVID-19. The drug's ability to regulate the balance between pro-inflammatory Th17 cells and anti-inflammatory Treg cells suggests its potential in mitigating inflammation and restoring T cell functionality. Furthermore, metformin's modulation of the gut microbiota, particularly changes in bacterial taxa and the production of short-chain fatty acids, may contribute to its therapeutic effects. The interplay between metformin, bile acids, the gut microbiome, glucagon-like peptide-1 secretion, and glycemic control has implications for the management of diabetes and potential interventions in COVID-19. By refreshing the current evidence, this review highlights the potential of metformin as a therapeutic option in the management of COVID-19, while also exploring its effects on the gut microbiome and immunometabolism.

Genetic Predictors of Comorbid Course of COVID-19 and MAFLD: A Comprehensive Analysis

Metabolic-associated fatty liver disease (MAFLD) and its potential impact on the severity of COVID-19 have gained significant attention during the pandemic. This review aimed to explore the genetic determinants associated with MAFLD, previously recognized as non-alcoholic fatty liver disease (NAFLD), and their potential influence on COVID-19 outcomes. Various genetic polymorphisms, including PNPLA3 (rs738409), GCKR (rs780094), TM6SF2 (rs58542926), and LYPLAL1 (rs12137855), have been investigated in relation to MAFLD susceptibility and progression. Genome-wide association studies and meta-analyses have revealed associations between these genetic variants and MAFLD risk, as well as their effects on lipid metabolism, glucose regulation, and liver function. Furthermore, emerging evidence suggests a possible connection between these MAFLD-associated polymorphisms and the severity of COVID-19. Studies exploring the association between indicated genetic variants and COVID-19 outcomes have shown conflicting results. Some studies observed a potential protective effect of certain variants against severe COVID-19, while others reported no significant associations. This review highlights the importance of understanding the genetic determinants of MAFLD and its potential implications for COVID-19 outcomes. Further research is needed to elucidate the precise mechanisms linking these genetic variants to disease severity and to develop gene profiling tools for the early prediction of COVID-19 outcomes. If confirmed as determinants of disease severity, these genetic polymorphisms could aid in the identification of high-risk individuals and in improving the management of COVID-19.

Metformin for Treatment of Acute COVID-19: Systematic Review of Clinical Trial Data Against SARS-CoV-2

BACKGROUND

Observational and preclinical data suggest metformin may prevent severe coronavirus disease 2019 (COVID-19) outcomes.

PURPOSE

We conducted a systematic review of randomized, placebo-controlled clinical trials of metformin treatment for COVID-19 to determine whether metformin affects clinical or laboratory outcomes in individuals infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and present a structured summary of preclinical data.

STUDY SELECTION

Two independent reviewers searched PubMed, Scopus, Cochrane COVID-19 Study Register, and ClinicalTrials.gov on 1 February 2023 with no date restrictions for trials where investigators randomized adults with COVID-19 to metformin versus control and assessed clinical and/or laboratory outcomes of interest. The Cochrane Risk of Bias 2 tool was used to assess bias.

DATA EXTRACTION

Two reviewers extracted data pertaining to prespecified outcomes of each interest from each included trial.

DATA SYNTHESIS

The synthesis plan was developed a priori and was guided by Synthesis Without Meta-analysis (SWiM) guidelines. Summary tables and narrative synthesis were used (PROSPERO, 2022, CRD42022349896). Three randomized trials met inclusion criteria. In two of the trials investigators found that metformin improved clinical outcomes (prevented need for oxygen and prevented need for acute health care use), and in the third trial a larger portion of adults with diabetes were enrolled but results did show a direction of benefit similar to that of the other trials in the per-protocol group. In the largest trial, subjects were enrolled during the delta and omicron waves and vaccinated individuals were included. The certainty of evidence that metformin prevents health care use due to COVID-19 was moderate per Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria. Many preclinical studies have shown metformin to be effective against SARS-CoV-2.

LIMITATIONS

Limitations include inclusion of only three trials and heterogeneity between trials.

CONCLUSIONS

Future trials will help define the role of metformin in COVID-19 treatment guidelines.

Metformin Therapy Changes Gut Microbiota Alpha-Diversity in COVID-19 Patients with Type 2 Diabetes: The Role of SARS-CoV-2 Variants and Antibiotic Treatment

The gut microbiota play a crucial role in maintaining host health and have a significant impact on human health and disease. In this study, we investigated the alpha diversity of gut microbiota in COVID-19 patients and analyzed the impact of COVID-19 variants, antibiotic treatment, type 2 diabetes (T2D), and metformin therapy on gut microbiota composition and diversity. We used a culture-based method to analyze the gut microbiota and calculated alpha-diversity using the Shannon H' and Simpson 1/D indices. We collected clinical data, such as the length of hospital stay (LoS), C-reactive protein (CRP) levels, and neutrophil-to-lymphocyte ratio. We found that patients with T2D had significantly lower alpha-diversity than those without T2D. Antibiotic use was associated with a reduction in alpha-diversity, while metformin therapy was associated with an increase. We did not find significant differences in alpha-diversity between the Delta and Omicron groups. The length of hospital stay, CRP levels, and NLR showed weak to moderate correlations with alpha diversity. Our findings suggest that maintaining a diverse gut microbiota may benefit COVID-19 patients with T2D. Interventions to preserve or restore gut microbiota diversity, such as avoiding unnecessary antibiotic use, promoting metformin therapy, and incorporating probiotics, may improve patient outcomes.

Clinically Evaluated COVID-19 Drugs with Therapeutic Potential for Biological Warfare Agents

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak resulted in hundreds of millions of coronavirus cases, as well as millions of deaths worldwide. Coronavirus Disease 2019 (COVID-19), the disease resulting from exposure to this pathogen, is characterized, among other features, by a pulmonary pathology, which can progress to "cytokine storm", acute respiratory distress syndrome (ARDS), respiratory failure and death. Vaccines are the unsurpassed strategy for prevention and protection against the SARS-CoV-2 infection. However, there is still an extremely high number of severely ill people from at-risk populations. This may be attributed to waning immune response, variant-induced breakthrough infections, unvaccinated population, etc. It is therefore of high importance to utilize pharmacological-based treatments, despite the progression of the global vaccination campaign. Until the approval of Paxlovid, an efficient and highly selective anti-SARS-CoV-2 drug, and the broad-spectrum antiviral agent Lagevrio, many pharmacological-based countermeasures were, and still are, being evaluated in clinical trials. Some of these are host-directed therapies (HDTs), which modulate the endogenic response against the virus, and therefore may confer efficient protection against a wide array of pathogens. These could potentially include Biological Warfare Agents (BWAs), exposure to which may lead to mass casualties due to disease severity and a possible lack of efficient treatment. In this review, we assessed the recent literature on drugs under advanced clinical evaluation for COVID-19 with broad spectrum activity, including antiviral agents and HDTs, which may be relevant for future coping with BWAs, as well as with other agents, in particular respiratory infections.

Repurposing clinically available drugs and therapies for pathogenic targets to combat SARS-CoV-2

The coronavirus disease 2019 (COVID-19) pandemic has affected a large portion of the global population, both physically and mentally. Current evidence suggests that the rapidly evolving coronavirus subvariants risk rendering vaccines and antibodies ineffective due to their potential to evade existing immunity, with enhanced transmission activity and higher reinfection rates that could lead to new outbreaks across the globe. The goal of viral management is to disrupt the viral life cycle as well as to relieve severe symptoms such as lung damage, cytokine storm, and organ failure. In the fight against viruses, the combination of viral genome sequencing, elucidation of the structure of viral proteins, and identifying proteins that are highly conserved across multiple coronaviruses has revealed many potential molecular targets. In addition, the time- and cost-effective repurposing of preexisting antiviral drugs or approved/clinical drugs for these targets offers considerable clinical advantages for COVID-19 patients. This review provides a comprehensive overview of various identified pathogenic targets and pathways as well as corresponding repurposed approved/clinical drugs and their potential against COVID-19. These findings provide new insight into the discovery of novel therapeutic strategies that could be applied to the control of disease symptoms emanating from evolving SARS-CoV-2 variants.

The F/B ratio as a biomarker for inflammation in COVID-19 and T2D: Impact of metformin

The pandemic of COVID-19 has highlighted the intricate relationship between gut microbiome and overall health. Recent studies have shown that the Firmicutes/Bacteroidetes ratio in the gut microbiome may be linked to various diseases including COVID-19 and type 2 diabetes (T2D). Understanding the link between gut microbiome and these diseases is essential for developing strategies for prevention and treatment. In this study, 115 participants were recruited and divided into three groups: 1st group: T2D patients and healthy controls, 2nd group: COVID-19 patients with and without T2D, 3rd group: T2D patients with COVID-19 treated with or without metformin. Gut microbial composition at the phylum level was assessed using qRT-PCR with universal primers targeting the bacterial 16 S rRNA gene and specific primers for Firmicutes and Bacteroidetes. Data was analyzed using one-way ANOVA, logistic regression, and Spearman's rank correlation coefficient. The study found that the ratio of Firmicutes to Bacteroidetes (F/B) was higher in patients with both T2D and COVID-19 compared to those with only T2D or COVID-19. Additionally, the F/B ratio was positively correlated with C-reactive protein (CRP) in T2D and COVID-19 patients. The study also suggests that metformin treatment may affect this correlation. Logistic regression analysis showed that the F/B ratio was significantly associated with CRP. These findings suggest that the F/B ratio may be a potential biomarker for inflammation in T2D and COVID-19 patients and metformin treatment may have an effect on the correlation between F/B and CRP levels.

The Intersection of COVID-19 and Metabolic-Associated Fatty Liver Disease: An Overview of the Current Evidence

The global population is currently experiencing the impact of the SARS-CoV-2 coronavirus, which has caused the Coronavirus Disease 2019 (COVID-19) pandemic. With our profound comprehension of COVID-19, encompassing the involvement sequence of the respiratory tract, gastrointestinal system, and cardiovascular apparatus, the multiorgan symptoms of this infectious disease have been discerned. Metabolic-associated fatty liver disease (MAFLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is a pervasive public health concern intricately linked with metabolic dysregulation and estimated to afflict one-fourth of the global adult population. The burgeoning focus on the association between COVID-19 and MAFLD is justified by the potential role of the latter as a risk factor for both SARS-CoV-2 infection and the subsequent emergence of severe COVID-19 symptoms. Investigations have suggested that changes in both innate and adaptive immune responses among MAFLD patients may play a role in determining the severity of COVID-19. The remarkable similarities observed in the cytokine pathways implicated in both diseases imply the existence of shared mechanisms governing the chronic inflammatory responses characterizing these conditions. The effect of MAFLD on the severity of COVID-19 illness remains uncertain, as indicated by conflicting results in cohort investigations.

Immunometabolic Signature during Respiratory Viral Infection: A Potential Target for Host-Directed Therapies

RNA viruses are known to induce a wide variety of respiratory tract illnesses, from simple colds to the latest coronavirus pandemic, causing effects on public health and the economy worldwide. Influenza virus (IV), parainfluenza virus (PIV), metapneumovirus (MPV), respiratory syncytial virus (RSV), rhinovirus (RhV), and coronavirus (CoV) are some of the most notable RNA viruses. Despite efforts, due to the high mutation rate, there are still no effective and scalable treatments that accompany the rapid emergence of new diseases associated with respiratory RNA viruses. Host-directed therapies have been applied to combat RNA virus infections by interfering with host cell factors that enhance the ability of immune cells to respond against those pathogens. The reprogramming of immune cell metabolism has recently emerged as a central mechanism in orchestrated immunity against respiratory viruses. Therefore, understanding the metabolic signature of immune cells during virus infection may be a promising tool for developing host-directed therapies. In this review, we revisit recent findings on the immunometabolic modulation in response to infection and discuss how these metabolic pathways may be used as targets for new therapies to combat illnesses caused by respiratory RNA viruses.

Efficacy of interferon alpha for the treatment of hospitalized patients with COVID-19: A meta-analysis

INTRODUCTION

IFN-α intervention may block SARS-CoV-2 replication and normalize the deregulated innate immunity of COVID-19.

AIM

This meta-analysis aimed to investigate the efficacy of interferon IFN-α-containing regimens when treating patients with moderate-to-severe COVID-19.

MATERIAL AND METHODS

PubMed, SCOPUS, and ClinicalTrials.gov were searched from inception to 15 January 2022. A systematic literature search was conducted by applying relevant terms for 'COVID-19' and 'interferon-α'. The primary outcome enclosed the all-cause hospital mortality. The secondary outcomes constituted the length of hospital stay; hospital discharge; nucleic acid negative conversion.

RESULTS

Eleven studies are enclosed in the meta-analysis. No significant difference in the all-cause mortality rate was found between the study and control groups (OR 0.2; 95% CI 0.05-1.2; I2 = 96%). The implementation of interferon did not influence such outcomes as the length of hospital stay (OR 0.9; 95% CІ, 0.3-2.6; I2 = 91%), nucleic acid negative conversion (OR 0.8; 95% CI, 0.04-17.2; I2 = 94%). Nevertheless, IFN-α treatment resulted in a higher number of patients discharged from the hospital (OR 26.6; 95% CІ, 2.7-254.3; I2 = 95%).

CONCLUSIONS

Thus, IFN-α does not benefit the survival of hospitalized COVID-19 patients but may increase the number of patients discharged from the hospital.

SYSTEMATIC REVIEW REGISTRATION

www.crd.york.ac.uk/prospero, identifier (CRD42022374589).

Gut microbiota in patients with COVID-19 and type 2 diabetes: A culture-based method

Background

The global pandemic of coronavirus disease 2019 (COVID-19) continues to affect people around the world, with one of the most frequent comorbidities being Type 2 Diabetes (T2D). Studies have suggested a link between disbalances in gut microbiota and these diseases, as well as with COVID-19, potentially due to inflammatory dysfunction. This study aims to analyze the changes in gut microbiota in COVID-19 patients with T2D using a culture-based method.

Methods

The stool samples were taken from 128 patients with confirmed COVID-19. Changes in the composition of gut microbiota were analyzed by culture-based method. The study used chi-squared and t-test to find significant differences in gut bacteria between samples and non-parametric correlation analysis to examine relationship between gut bacteria abundance, C-reactive protein (CRP) levels and length of stay (LoS) in COVID-19 patients without T2D.

Results

The gut microbiota of T2D patients with COVID-19 showed increased Clostridium spp., Candida spp., and decreased Bifidobacterium spp., Lactobacillus spp. Metformin-treated patients with T2D and COVID-19 without antibiotic treatment showed increased Bacteroides spp., Lactobacillus spp., and decreased Enterococcus, Clostridium compared to the same group with antibiotic treatment. The study also found a positive correlation between the abundance of certain gut microbiota genera, such as Klebsiella spp. and Enterococcus spp., and CRP levels and LoS in COVID-19 patients without and with T2D, while the abundance of other genera, such as Bifidobacterium spp. and Lactobacillus spp., was found to have a negative correlation.

Conclusion

In conclusion, this study provides important insights into the gut microbiota composition of SARS-CoV-2-infected individuals with T2D and its potential impact on the course of the disease. The findings suggest that certain gut microbiota genera may be associated with increased CRP levels and longer hospital stays. The significance of this study lies in the fact that it highlights the potential role of gut microbiota in the progression of COVID-19 in patients with T2D, and may inform future research and treatment strategies for this patient population. The future impact of this study could include the development of targeted interventions to modulate gut microbiota in order to improve outcomes for COVID-19 patients with T2D.

Correlation between Medications Used during COVID Infection and Post-conditions after the Acute Phase of Infection: A Cross-sectional Study

Background:

During the COVID-19 pandemic, off-label medication prescribing and utilizing herbal products and multiple vitamins in the treatment, prevention, and symptom management of COVID-19 was an urgently needed practice to halt the SARS-CoV-2 infection crisis and progression.

Objectives:

This study aimed to determine the correlation between medications used during the pandemic and SARS-CoV-2 infection post-recovery symptoms.

Methods:

A cross-sectional questionnaire-based study was conducted on recovered COVID-19 patients. There were 20 multiple-choice questions, including patient demographics, treatment, and post-recovery symptoms. Chi-square and Fisher’s exact tests were used to investigate significant relationships. In addition, Binary logistic regression was performed to determine confounders. Data were analyzed using SPSS version 22.

Results:

Medications and supplements varied in their therapeutic effects on SARS-CoV-2 post-recovery symptoms. Patients who took vitamin D and calcium experienced increased symptom frequency, and patients taking ACE inhibitors experienced more headaches and coughs. Furthermore, patients receiving azithromycin were asymptomatic after recovery. Patients who took H2 antagonists reported persistent headaches and muscle pain.

Conclusion:

Patients infected with SARS-CoV-2 have responded differently to medications, multivitamins, and herbal supplements. Patients reported resolution of some symptoms and persistence of others post-recovery. Therefore, expert opinion should be considered in COVID-19 management until randomized controlled trials answer many questions and determine medications' safety and efficacy in prevention, treatment strategies, and symptoms of SARS-CoV-2 infection post-recovery.

Sars-Cov2 Induced Biochemical Mechanisms in Liver Damage and Intestinal Lesions

Multiple pathogenic mechanisms are found in SARS-CoV2 systemic inflammation. Oxidative stress, altered proteolysis, hypercoagulation, and metabolic disorders are significant in virus-induced lesions. The study aimed to investigate the biochemical mechanism of virus-induced disorders and determine the biochemical features in SARS-CoV2-associated liver damage and intestine lesions. A retrospective case series of ninety-two patients diagnosed with COVID-19 pnemonia. The ACE, α1-proteinase inhibitor, trypsin-like proteinase, and elastase activity were measured. Nitrites level was detected in reaction with Griess reagent. The ELISA kit measured Troponin, C-peptide, leptin, adiponectin, PAR4, and neuropilin level. It was obtained an increase in ACE activity and nitrites ions content in SARS-CoV2 associated patients. The hyperglycemia and an increase in adipose tissue-derived hormones guided the virus-induced metabolic disorders. Proteolysis activation was revealed in SARS-CoV2 pneumonia patients. The found molecular event was accompanied by hyperglycemia induction. Multiorgan lesions manifest in in cardiac failure, which was detected in patients with ARDS. Moreover, high arterial blood pressure in patients with COVID-19 was associated with the hyperglycemia and increased ACE activity and NO ions level. Liver damage was specific for COVID-19-associated patients with severe ARDS and heart failure. Proteolysis overactivation resulting in vasoactive substances imbalance was detected in patients with the intestinal lesions. The obtained data shows the the neuropilin-dependent axis in damage prevalence in the intestine. Metabolic disorders resulting in the growth of adipose-derived tissue hormones, nitrites, and neuropilin levels was triggered by prolonged inflammation. So, the impaired metabolism and SARS-CoV2 associated hyperglycemia influence on SARS-CoV2 multiple mechanisms. Gastrointestinal manifestations in SARS-CoV2 infection was found to be related to various biochemical and molecular tools. ACE2 receptors axis is prevalent for liver damage, but NRP-1 protein (neuropilin), NO derivatives, and adipose tissue-derived hormones are essential for intestinal lesions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12291-022-01089-x.

Advances in T Cells Based on Inflammation in Metabolic Diseases

With the increasing incidence of metabolic diseases year by year and their impact on the incidence of cardiovascular diseases, metabolic diseases have attracted great attention as a major health care problem, but there is still no effective treatment. Oxidative stress and inflammation are the main mechanisms leading to metabolic diseases. T cells are involved in the inflammatory response, which can also regulate the development of metabolic diseases, CD4+ T cells and CD8+ T cells are mainly responsible for the role. Th1 and Th17 differentiated from CD4+ T promote inflammation, while Th2 and Treg inhibit inflammation. CD8+ T cells also contribute to inflammation. The severity and duration of inflammatory reactions can also lead to different degrees of progression of metabolic diseases. Moreover, mTOR, PI3K-Akt, and AMPK signaling pathways play unique roles in the regulation of T cells, which provide a new direction for the treatment of metabolic diseases in the future. In this review, we will elaborate on the role of T cells in regulating inflammation in various metabolic diseases, the signaling pathways that regulate T cells in metabolic diseases, and the latest research progress.

Potential Therapeutic Benefits of Metformin Alone and in Combination with Sitagliptin in the Management of Type 2 Diabetes Patients with COVID-19

Type 2 diabetes mellitus (T2DM) is a potential risk factor for the development of COVID-19 and is associated with higher severity and mortality rates. T2DM patients are commonly treated with metformin monotherapy or metformin plus sitagliptin. In the present case-control, single-center cohort study, a total number of 112 T2DM patients suffering from COVID-19 and aged 44−62 years old were compared with 78 T2DM patients without COVID-19 and aged 42−56 years old. Both the patient group and the control group were allocated into four groups. Group A: T2DM patients with COVID-19 on metformin treatments plus standard therapy (n = 60); group B: T2DM patients with COVID-19 on metformin plus sitagliptin plus standard therapy (n = 52); group C: T2DM patients without COVID-19 on metformin treatments (n = 40); and group D: T2DM patients without COVID-19 on metformin plus sitagliptin (n = 38). The investigation duration was 2−3 weeks. Anthropometric measurements, serological and biochemical investigations, pulmonary radiological findings, and clinical outcomes were evaluated. Only 101 T2DM patients with COVID-19 continued the study, 71 (70.29%) with mild-moderate COVID-19 and 30 (29.7%) with severe COVID-19 were compared with 78 T2DM patients as a control. Inflammatory biomarkers (C reactive protein, ferritin, and procalcitonin), a lung injury biomarker (lactate dehydrogenase), and a coagulopathy biomarker (D-dimer) were elevated in severe COVID-19 patients compared with mild-moderate COVID-19 (p < 0.05) and T2DM patients (p < 0.05). However, metformin plus sitagliptin was more effective than metformin monotherapy in T2DM patients with COVID-19, as evidenced by the mitigation of oxidative stress, CT scan score, and clinical outcomes. The present study confirmed the protective effects of this combination against the development of COVID-19 severity, as most T2DM COVID-19 patients develop mild-moderate forms. Herein, the combination of metformin and sitagliptin may lead to more beneficial effects than metformin monotherapy.

The characteristics and outcomes of COVID-19 among diabetic patients in Wad-Medani isolation center from September to December 2020: A cross-sectional study

Background and Aims

Corona virus disease-19 (COVID-19) is a recently discovered infection that transmitted briskly worldwide. In this disease (COVID-19), it was discovered that several disorders, such diabetes, increased the severity and fatality rate. Until now, studies investigating the correlation between diabetes and COVID-19 in Sudan have not yet been conducted. Thus we aimed to evaluated the characteristics and outcomes of COVID-19 among diabetic patients.

Methods

A prospective study included 70 diabetic patients with COVID-19 in Wad-Medani Isolation Center from September to December 2020. Data concerning demographics and clinical characteristics, as well as outcomes were collected.

Results

Out of 70 patients, 46 (66%) were men and 24 (34%) were women; the average age was 63 ± 12 years. In diabetes mellitus (DM) types, 69 (98.6%) patient were T2DM. The average of DM duration was 10 ± 6.2 years. Insulin was the major DM medication used by more one-half of study patients (n = 37; 52.9%). Newly discovered DM after COVD-19 infection was encountered in 5 (7.1%) patients. Most of the study subjects (n = 44; 63%) had moderately severe form of disease. Hypertension was the commonest comorbid in 29 (41.4%) patients. The intensive care unit admission rate among our study group was 10% (n = 7). The mortality rate among our study patients was found to be 11.4% (n = 8). Dead patients were significantly had high HbA1c levels (11.6 ± 7% vs. 8.8 ± 5%; p = 0.001). Additionally, all individuals with a severe COVID-19 illness (n = 6; 100%) were dead comparing to no patient died with mild covid illness and 4.5% patients with moderately severe infection (p < 0.001).

Conclusion

The majority of COVID-19 diabetic patients were males and older in age. Most of the patients presented with moderate severity and moderately uncontrolled DM. Hypertension was the major comorbidity. The mortality rate was as high as 11.4% and associated with high HbA1c levels and severe form of COVID-19 as well.

The potential role of ischaemia-reperfusion injury in chronic, relapsing diseases such as rheumatoid arthritis, Long COVID, and ME/CFS: evidence, mechanisms, and therapeutic implications

Ischaemia-reperfusion (I-R) injury, initiated via bursts of reactive oxygen species produced during the reoxygenation phase following hypoxia, is well known in a variety of acute circumstances. We argue here that I-R injury also underpins elements of the pathology of a variety of chronic, inflammatory diseases, including rheumatoid arthritis, ME/CFS and, our chief focus and most proximally, Long COVID. Ischaemia may be initiated via fibrin amyloid microclot blockage of capillaries, for instance as exercise is started; reperfusion is a necessary corollary when it finishes. We rehearse the mechanistic evidence for these occurrences here, in terms of their manifestation as oxidative stress, hyperinflammation, mast cell activation, the production of marker metabolites and related activities. Such microclot-based phenomena can explain both the breathlessness/fatigue and the post-exertional malaise that may be observed in these conditions, as well as many other observables. The recognition of these processes implies, mechanistically, that therapeutic benefit is potentially to be had from antioxidants, from anti-inflammatories, from iron chelators, and via suitable, safe fibrinolytics, and/or anti-clotting agents. We review the considerable existing evidence that is consistent with this, and with the biochemical mechanisms involved.

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.

The role of AMPK-dependent pathways in cellular and molecular mechanisms of metformin: a new perspective for treatment and prevention of diseases

Metformin can suppress gluconeogenesis and reduce blood sugar by activating adenosine monophosphate-activated protein kinase (AMPK) and inducing small heterodimer partner (SHP) expression in the liver cells. The main mechanism of metformin's action is related to its activation of the AMPK enzyme and regulation of the energy balance. AMPK is a heterothermic serine/threonine kinase made of a catalytic alpha subunit and two subunits of beta and a gamma regulator. This enzyme can measure the intracellular ratio of AMP/ATP. If this ratio is high, the amino acid threonine 172 available in its alpha chain would be activated by the phosphorylated liver kinase B1 (LKB1), leading to AMPK activation. Several studies have indicated that apart from its significant role in the reduction of blood glucose level, metformin activates the AMPK enzyme that in turn has various efficient impacts on the regulation of various processes, including controlling inflammatory conditions, altering the differentiation pathway of immune and non-immune cell pathways, and the amelioration of various cancers, liver diseases, inflammatory bowel disease (IBD), kidney diseases, neurological disorders, etc. Metformin's activation of AMPK enables it to control inflammatory conditions, improve oxidative status, regulate the differentiation pathways of various cells, change the pathological process in various diseases, and finally have positive therapeutic effects on them. Due to the activation of AMPK and its role in regulating several subcellular signalling pathways, metformin can be effective in altering the cells' proliferation and differentiation pathways and eventually in the prevention and treatment of certain diseases.

Immunoregulatory Intestinal Microbiota and COVID-19 in Patients with Type Two Diabetes: A Double-Edged Sword

Coronavirus disease 2019, or COVID-19, is a major challenge facing scientists worldwide. Alongside the lungs, the system of organs comprising the GI tract is commonly targeted by COVID-19. The dysbiotic modulations in the intestine influence the disease severity, potentially due to the ability of the intestinal microbiota to modulate T lymphocyte functions, i.e., to suppress or activate T cell subpopulations. The interplay between the lungs and intestinal microbiota is named the gut-lung axis. One of the most usual comorbidities in COVID-19 patients is type 2 diabetes, which induces changes in intestinal microbiota, resulting in a pro-inflammatory immune response, and consequently, a more severe course of COVID-19. However, changes in the microbiota in this comorbid pathology remain unclear. Metformin is used as a medication to treat type 2 diabetes. The use of the type 2 diabetes drug metformin is a promising treatment for this comorbidity because, in addition to its hypoglycemic action, it can increase amount of intestinal bacteria that induce regulatory T cell response. This dual activity of metformin can reduce lung damage and improve the course of the COVID-19 disease.

PI3K/Akt/mTOR pathway: a potential target for anti-SARS-CoV-2 therapy

Coronavirus disease 2019 (COVID-19) is a viral infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A single-stranded RNA virus from a β-Coronaviridae family causes acute clinical manifestations. Its high death rate and severe clinical symptoms have turned it into the most significant challenge worldwide. Up until now, several effective COVID-19 vaccines have been designed and marketed, but our data on specialized therapeutic drugs for the treatment of COVID-19 is still limited. In order to synthesis virus particles, SARS-CoV-2 uses host metabolic pathways such as phosphoinositide3-kinase (PI3K)/protein kinase B (PKB, also known as AKT)/mammalian target of rapamycin (mTOR). mTOR is involved in multiple biological processes. Over-activation of the mTOR pathway improves viral replication, which makes it a possible target in COVID-19 therapy. Clinical data shows the hyperactivation of the mTOR pathway in lung tissues during respiratory viral infections. However, the exact impact of mTOR pathway inhibitors on the COVID-19 severity and death rate is yet to be thoroughly investigated. There are several mTOR pathway inhibitors. Rapamycin is the most famous inhibitor of mTORC1 among all. Studies on other respiratory viruses suggest that the therapeutic inhibitors of the mTOR pathway, especially rapamycin, can be a potential approach to anti-SARS-CoV-2 therapy. Using therapeutic methods that inhibit harmful immune responses can open a new chapter in treating severe COVID-19 disease. We highlighted the potential contribution of PI3K/Akt/mTOR inhibitors in the treatment of COVID-19.

Identification of potentially anti-COVID-19 active drugs using the connectivity MAP

Drug repurposing can be an interesting strategy for an emergency response to the severe acute respiratory syndrome-coronavirus-2, (SARS-COV-2), the causing agent of the coronavirus disease-19 (COVID-19) pandemic. For this, we applied the Connectivity Map (CMap) bioinformatic resource to identify drugs that generate, in the CMap database, gene expression profiles (GEP) that negatively correlate with a SARS-COV-2 GEP, anticipating that these drugs could antagonize the deleterious effects of the virus at cell, tissue or organism levels. We identified several anti-cancer compounds that target MDM2 in the p53 pathway or signaling proteins: Ras, PKBβ, Nitric Oxide synthase, Rho kinase, all involved in the transmission of proliferative and growth signals. We hypothesized that these drugs could interfere with the high rate of biomass synthesis in infected cells, a feature shared with cancer cells. Other compounds including etomoxir, triacsin-c, PTB1-IN-3, are known to modulate lipid metabolism or to favor catabolic reactions by activating AMPK. Four different anti-inflammatory molecules, including dexamethasone, fluorometholone and cytosporone-b, targeting the glucocorticoid receptor, cyclooxygenase, or NUR77 also came out of the analysis. These results represent a first step in the characterization of potential repositioning strategies to treat SARS-COV-2.

Association of blood glucose level and prognosis of inpatients with coexistent diabetes and COVID-19

Type 2 diabetes (T2D) increases the risk of coronavirus disease (COVID-19). This study investigates the association between glucose control of COVID-19 patients with T2D in first 7 days after hospital admission and prognosis. A total of 252 infected inpatients with T2D in China were included. Well-controlled blood glucose was defined as stable fasting blood glucose (FBG) levels in the range of 3.9-7.8 mmol/L during first 7 days using indicators of average (FBG_A), maximum (FBG_M) or first-time (FBG₁) FBG levels. The primary endpoint was admission to intensive care unit or death. Hazard ratio (HR) of poorly controlled glucose level group compared with well-controlled group were 4.96 (P = 0.021) for FBG_M and 5.55 (P = 0.014) for FBG_A. Well-controlled blood glucose levels in first 7 days could improve the prognosis of COVID-19 inpatients with diabetes.

Prognostic Factors for COVID-19 Hospitalized Patients with Preexisting Type 2 Diabetes

BACKGROUND

Type 2 diabetes (T2D) as a worldwide chronic disease combined with the COVID-19 pandemic prompts the need for improving the management of hospitalized COVID-19 patients with preexisting T2D to reduce complications and the risk of death. This study aimed to identify clinical factors associated with COVID-19 outcomes specifically targeted at T2D patients and build an individualized risk prediction nomogram for risk stratification and early clinical intervention to reduce mortality.

METHODS

In this retrospective study, the clinical characteristics of 382 confirmed COVID-19 patients, consisting of 108 with and 274 without preexisting T2D, from January 8 to March 7, 2020, in Tianyou Hospital in Wuhan, China, were collected and analyzed. Univariate and multivariate Cox regression models were performed to identify specific clinical factors associated with mortality of COVID-19 patients with T2D. An individualized risk prediction nomogram was developed and evaluated by discrimination and calibration.

RESULTS

Nearly 15% (16/108) of hospitalized COVID-19 patients with T2D died. Twelve risk factors predictive of mortality were identified. Older age (HR = 1.076, 95% CI = 1.014-1.143, p=0.016), elevated glucose level (HR = 1.153, 95% CI = 1.038-1.28, p=0.0079), increased serum amyloid A (SAA) (HR = 1.007, 95% CI = 1.001-1.014, p=0.022), diabetes treatment with only oral diabetes medication (HR = 0.152, 95%CI = 0.032-0.73, p=0.0036), and oral medication plus insulin (HR = 0.095, 95%CI = 0.019-0.462, p=0.019) were independent prognostic factors. A nomogram based on these prognostic factors was built for early prediction of 7-day, 14-day, and 21-day survival of diabetes patients. High concordance index (C-index) was achieved, and the calibration curves showed the model had good prediction ability within three weeks of COVID-19 onset.

CONCLUSIONS

By incorporating specific prognostic factors, this study provided a user-friendly graphical risk prediction tool for clinicians to quickly identify high-risk T2D patients hospitalized for COVID-19.