Recent Advances in the Treatment of Insulin Resistance Targeting Molecular and Metabolic Pathways: Fighting a Losing Battle?

Insulin resistance and cancer: molecular links and clinical perspectives

The association between insulin resistance (IR), type 2 diabetes mellitus (T2DM), and cancer is increasingly recognized and poses an escalating global health challenge, as the incidence of these conditions continues to rise. Studies indicate that individuals with T2DM have a 10-20% increased risk of developing various solid tumors, including colorectal, breast, pancreatic, and liver cancers. The relative risk (RR) varies depending on cancer type, with pancreatic and liver cancers showing a particularly strong association (RR 2.0-2.5), while colorectal and breast cancers demonstrate a moderate increase (RR 1.2-1.5). Understanding these epidemiological trends is crucial for developing integrated management strategies. Given the global rise in T2DM and cancer cases, exploring the complex relationship between these conditions is critical. IR contributes to hyperglycemia, chronic inflammation, and altered lipid metabolism. Together, these factors create a pro-tumorigenic environment conducive to cancer development and progression. In individuals with IR, hyperinsulinemia triggers the insulin-insulin-like growth factor (IGF1R) signaling pathway, activating cancer-associated pathways such as mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PIK3CA), which promote cell proliferation and survival, thereby supporting tumor growth. Both IR and T2DM are linked to increased morbidity and mortality in patients with cancer. By providing an in-depth analysis of the molecular links between insulin resistance and cancer, this review offers valuable insights into the role of metabolic dysfunction in tumor progression. Addressing insulin resistance as a co-morbidity may open new avenues for risk assessment, early intervention, and the development of integrated treatment strategies to improve patient outcomes.

Dapagliflozin combined with metformin improves blood glucose, bone metabolism and bone mineral density in elderly patients with type 2 diabetes mellitus complicated with osteoporosis

The incidence of type 2 diabetes mellitus (T2DM) complicated with osteoporosis (OP) (T2DM-OP) is growing. Dapagliflozin and metformin are commonly prescribed to manage glycemic levels in T2DM patients. We investigated the clinical efficacy of combining dapagliflozin with metformin in elderly patients with T2DM-OP. Totally 144 T2DM-OP patients were prospectively enrolled and allocated into two groups: the Metformin and Dapagliflozin + Metformin groups. Each group received treatment for 12 months. Fasting peripheral blood samples were collected before and after 12 months of treatment. Glycemic parameters and bone metabolic parameters were measured using oral glucose tolerance test, automatic biochemical analyzers, or liquid chromatography. Bone mineral density (BMD) changes at lumbar vertebrae (L1-4), femoral neck (FN) and total hip (TH) were assessed using dual-energy X-ray bone mineral densitometry. Pain severity was evaluated using the visual analog scale (VAS). The total effective rate, fracture incidence, and adverse reaction rate were also evaluated. After 12 months, both groups showed improvements in glycemic parameters, bone metabolic parameters, and BMD at L1-4, FN, and TH, and reductions in VAS scores. The Dapagliflozin + Metformin group exhibited more significant improvements. The overall effective rate was higher and fracture incidence, was lower in Dapagliflozin + Metformin group, with comparable rates of adverse reactions and safety profiles between the two groups. Taken together, treatment with a combination of dapagliflozin and metformin led to improvements in blood glucose levels, bone metabolism, and BMD in elderly patients with T2DM-OP, demonstrating superior efficacy and safety compared to metformin monotherapy.

Insulin-Sensitizing Properties of Decoctions from Leaves, Stems, and Roots of Cucumis prophetarum L

Type 2 diabetes mellitus (T2DM) is a chronic disease characterized by insulin resistance and impaired beta-cell secretory function. Since existing treatments often present side effects based on different mechanisms, alternative therapeutic options are needed. In this scenario, the present study first evaluates the cytotoxicity of decoctions from the leaves, stems, and roots of Cucumis prophetarum L. on HepG2 and L6C5 cells. The extracts were chemically investigated by UV-Vis and ATR-FTIR spectroscopic techniques and by ultra high-performance chromatographic techniques, coupled with high-resolution mass spectrometry. Briefly, decoctions from the leaves and stems were mainly composed of apigenin C-glycosides, while the root decoction was rich in raffinose and cucumegastigmane II. To evaluate the insulin-sensitizing properties of the extracts in insulin-resistant L6 myoblasts, an evaluation by Western blot analysis of the proteins in the insulin signaling pathway was then performed. Particularly, key proteins of insulin signaling were investigated, i.e., insulin receptor substrate (IRS-1), protein kinase B (PKB/AKT), and glycogen synthase kinase-3 (GSK-3β), which have gained considerable attention from scientists for the treatment of diabetes. Under all conditions tested, the three decoctions showed low cytotoxicity. The stem and root decoction (300 μg/mL) resulted in a significant increase in the levels of p-IRS-1 (Tyr612), GSK3β (Ser9), and p-AMPK (Thr172) compared to those of the palmitic acid-treated group, and the leaf decoction resulted an increase in the level of p-IRS-1 (Tyr612) and p-AMPK (Thr172) and a decrease in p-GSK3β (Ser9) compared to the levels for the palmitic acid-treated group. The root decoction also reduced the level of p-mToR (Ser2448). Overall, the acquired data demonstrate the effect of reducing insulin resistance induced by the investigated decoctions, opening new scenarios for the evaluation of these effects aimed at counteracting diabetes and related diseases in animal models.

The Complex Role of Matrix Metalloproteinase-2 (MMP-2) in Health and Disease

Matrix metalloproteinase-2 (MMP-2), a zinc-dependent enzyme, plays a critical role in the degradation and remodeling of the extracellular matrix (ECM). As a member of the gelatinase subgroup of matrix metalloproteinases, MMP-2 is involved in a variety of physiological processes, including tissue repair, wound healing, angiogenesis, and embryogenesis. It is primarily responsible for the degradation of type IV and V collagen, fibronectin, laminin, and elastin, which are essential components of the ECM. MMP-2 is secreted as an inactive pro-enzyme (proMMP-2) and activated through proteolytic cleavage, with its activity being precisely regulated by tissue inhibitors of metalloproteinases (TIMPs). Dysregulation of MMP-2 has been linked to a variety of pathological conditions, including cardiovascular diseases, diabetic complications, kidney diseases, and cancer. In cardiovascular diseases, it contributes to vascular remodeling, atherosclerosis, and aneurysms, while in fibrotic diseases, it mediates excessive ECM degradation leading to tissue scarring. In diabetes, elevated MMP-2 activity exacerbates complications such as nephropathy, retinopathy, and cardiovascular disease. In cancer, MMP-2 facilitates tumor invasion and metastasis by degrading ECM components and promoting angiogenesis. Despite its essential roles in both physiological and pathological processes, targeting MMP-2 for therapeutic purposes presents challenges due to its dual functions in tissue remodeling and repair, raising concerns about unplanned consequences such as impaired tissue healing or excessive tissue damage. These challenges underscore the need for future research to focus on developing selective modulators that can precisely balance their activity under specific disease environments. Clinical trials targeting MMP-2 modulation highlight the potential of gelatinase inhibitors, including those targeting MMP-2, to reduce tumor progression in fibrosarcoma, breast, and lung cancers. This paper reviews the structure, function, and regulation of MMP-2, its involvement in disease pathogenesis, and the potential challenges in the therapeutic implications of modulating its activity.

The Relationship Between Lycopene and Metabolic Diseases

Background: Metabolic syndrome, obesity, and type 2 diabetes are closely related. They are characterized by chronic inflammation and oxidative stress. Obesity is the most important risk factor for metabolic syndrome and type 2 diabetes. Metabolic syndrome is characterized by insulin resistance and elevated blood glucose levels, among other conditions. These disorders contribute to the development of type 2 diabetes, which can exacerbate other metabolic problems. Methods: Numerous studies indicate that diet and nutrients can have a major impact on preventing and treating these conditions. One such ingredient is lycopene. It is a naturally occurring carotenoid with a unique chemical structure. It exhibits strong antioxidant and anti-inflammatory properties due to its conjugated double bonds and its ability to neutralize reactive oxygen species. Its properties make lycopene indirectly affect many cellular processes. The article presents studies in animal models and humans on the activity of this carotenoid in metabolic problems. Results: The findings suggest that lycopene's antioxidant and anti-inflammatory activities make it a promising candidate for the prevention and treatment of metabolic syndrome, obesity, and type 2 diabetes. Conclusions: This review underscores the potential of lycopene as a beneficial dietary supplement in improving metabolic health and reducing the risk of associated chronic diseases. The conditions described are population diseases, so research into compounds with properties such as lycopene is growing in popularity.

Red cell distribution width/albumin ratio as a marker for metabolic syndrome: findings from a cross-sectional study

BACKGROUND

Metabolic syndrome (MetS) imposes a significant health burden on patients globally. Chronic low-grade inflammation is pivotal in the onset and progression of this condition. However, the role of the novel inflammatory marker, red cell distribution width to albumin ratio (RAR), in the development of MetS remains unclear.

METHODS

This population-based cross-sectional study utilized data from the 2011-2020 National Health and Nutrition Examination Survey (NHANES). Participants included individuals over 18 years old with complete data on serum albumin concentration, red cell distribution, and MetS and its components. MetS was defined using the criteria established by the National Cholesterol Education Program Adult Treatment Panel III. The calculation formula for RAR is: RAR = Red cell distribution width (%)/serum albumin (g/dL). Study participants were stratified into four quartiles based on RAR levels. Logistic regression analysis and subgroup analysis were employed to explore the independent interaction between RAR and MetS, as well as investigate the relationship between RAR levels and the specific components of MetS. Finally, the receiver operating characteristic (ROC) curve was used to assess the predictive efficacy of RAR for MetS.

RESULTS

A total of 4899 participants were included in this study, comprising 2450 males and 2449 females; 1715 individuals (35.01%) were diagnosed with MetS. As the quartile of RAR increased, the proportion of individuals with MetS also increased. Spearman correlation analysis indicated a positive correlation between RAR and the insulin resistance index HOMA-IR. Logistic regression analysis, adjusting for multiple confounding factors, showed that each standard deviation increase in RAR was associated with a significant 1.665-fold increase (95% CI, 1.404-1.975; P < 0.001) in the odds of MetS prevalence. In logistic regression analysis stratified by quartiles of RAR, the risks of MetS in Q1-Q4 were 1.372 (95% CI, 1.105-1.704; P = 0.004), 1.783 (95% CI, 1.434-2.216; P < 0.001), and 2.173 (95% CI, 1.729-2.732; P < 0.001), respectively. Subgroup analyses and interaction tests demonstrated that gender, age, race, education, smoking status, and physical activity modified the positive association between RAR and MetS (p for interaction < 0.05). Additionally, analysis of the area under the receiver operating characteristic (ROC) curve showed that the optimal cutoff value for predicting MetS using RAR was 3.1348 (sensitivity: 59.9%; specificity: 60.6%; and AUC: 0.628).

CONCLUSIONS

Increasing RAR levels are associated with a higher risk of MetS. Therefore, greater attention should be given to patients with high RAR levels for improved prevention and treatment of MetS.

Therapeutic Potential of Luteolin for Diabetes Mellitus and Its Complications

The global prevalence of diabetes mellitus (DM) and its complications has been showing an upward trend in the past few decades, posing an increased economic burden to society and a serious threat to human life and health. Therefore, it is urgent to investigate the effectiveness of complementary and alternative therapies for DM and its complications. Luteolin is a kind of polyphenol flavonoid with widely existence in some natural resources, as a safe dietary supplement, it has been widely studied and reported in the treatment of DM and its complications. This review demonstrates the therapeutic potential of luteolin in DM and its complications, and elucidates the action mode of luteolin at the molecular level. It is characterized by anti-inflammatory, antioxidant, and neuroprotective effects. In detail, luteolin can not only improve endothelial function, insulin resistance and β-cell dysfunction, but also inhibit the activities of dipeptidyl peptidase-4 and α-glucosidase. However, due to the low water solubility and oral bioavailability of luteolin, its application in the medical field is limited. Therefore, great importance should be attached to the joint application of luteolin with current advanced science and technology. And more high-quality human clinical studies are needed to clarify the effects of luteolin on DM patients.

Recent progress in artificial intelligence and machine learning for novel diabetes mellitus medications development

Diabetes mellitus, stemming from either insulin resistance or inadequate insulin secretion, represents a complex ailment that results in prolonged hyperglycemia and severe complications. Patients endure severe ramifications such as kidney disease, vision impairment, cardiovascular disorders, and susceptibility to infections, leading to significant physical suffering and imposing substantial socio-economic burdens. This condition has evolved into an increasingly severe health crisis. There is an urgent need to develop new treatments with improved efficacy and fewer adverse effects to meet clinical demands. However, novel drug development is costly, time-consuming, and often associated with side effects and suboptimal efficacy, making it a major challenge. Artificial Intelligence (AI) and Machine Learning (ML) have revolutionized drug development across its comprehensive lifecycle, spanning drug discovery, preclinical studies, clinical trials, and post-market surveillance. These technologies have significantly accelerated the identification of promising therapeutic candidates, optimized trial designs, and enhanced post-approval safety monitoring. Recent advances in AI, including data augmentation, interpretable AI, and integration of AI with traditional experimental methods, offer promising strategies for overcoming the challenges inherent in AI-based drug discovery. Despite these advancements, there exists a notable gap in comprehensive reviews detailing AI and ML applications throughout the entirety of developing medications for diabetes mellitus. This review aims to fill this gap by evaluating the impact and potential of AI and ML technologies at various stages of diabetes mellitus drug development. It does that by synthesizing current research findings and technological advances so as to effectively control diabetes mellitus and mitigate its far-reaching social and economic impacts. The integration of AI and ML promises to revolutionize diabetes mellitus treatment strategies, offering hope for improved patient outcomes and reduced healthcare burdens worldwide.

Allulose mitigates chronic enteritis by reducing mitochondria dysfunction via regulating cathepsin B production

Metabolic changes have been linked to the development of inflammatory bowel disease (IBD), which includes colitis. Allulose, an endogenous bioactive monosaccharide, is vital to the synthesis of numerous compounds and metabolic processes within living organisms. Nevertheless, the precise biochemical mechanism by which allulose inhibits colitis remains unknown. Allulose is an essential and intrinsic protector of the intestinal mucosal barrier, as it maintains the integrity of tight junctions in the intestines, according to the current research. It is also important to know that there is a link between the severity of inflammatory bowel disease (IBD) and colorectal cancer (CRC), chemically-induced colitis in rodents, and lower levels of allulose in the blood. Mice with colitis, either caused by dextran sodium sulphate (DSS) or naturally occurring colitis in IL-10-/- mice, had less damage to their intestinal mucosa after being given allulose. Giving allulose to a colitis model starts a chain of reactions because it stops cathepsin B from ejecting and helps lysosomes stick together. This system effectively stops the activity of myosin light chain kinase (MLCK) when intestinal epithelial damage happens. This stops the breakdown of tight junction integrity and the start of mitochondrial dysfunction. To summarise, the study's findings have presented data that supports the advantageous impact of allulose in reducing the advancement of colitis. Its ability to stop the disruption of the intestinal barrier enables this. Therefore, allulose has potential as a medicinal supplement for treating colitis.

Gut microbiota's causative relationship with peripheral artery disease: a Mendelian randomization study

Introduction

The relationship between gut microbiota and peripheral artery disease (PAD) remains understudied. While traditional risk factors like smoking and hyperlipidemia are well-understood, our study aims to determine the potential causative association of gut microbiota with PAD using Mendelian Randomization.

Methods

Data from the International MiBioGen Consortium and the FinnGen research project were used to study 211 bacterial taxa. Instrumental variables, comprising 2079 SNPs, were selected based on significance levels and linkage disequilibrium. Analyses were conducted utilizing the inverse-variance weighted (IVW) method and other statistical MR techniques to mitigate biases, processed in R (v4.3.1) with the TwosampleMR package.

Results

Three bacterial taxa, namely genus Coprococcus2, RuminococcaceaeUCG004, and RuminococcaceaeUCG010, emerged as protective factors against PAD. In contrast, family. FamilyXI and the genus Lachnoclostridium and LachnospiraceaeUCG001 were identified as risk factors.

Conclusion

Our findings hint at a causative association between certain gut microbiota and PAD, introducing new avenues for understanding PAD's etiology and developing effective treatments. The observed associations now warrant further validation in varied populations and detailed exploration at finer taxonomic levels.

Changes in Cells Associated with Insulin Resistance

Insulin is a polypeptide hormone synthesized and secreted by pancreatic β-cells. It plays an important role as a metabolic hormone. Insulin influences the metabolism of glucose, regulating plasma glucose levels and stimulating glucose storage in organs such as the liver, muscles and adipose tissue. It is involved in fat metabolism, increasing the storage of triglycerides and decreasing lipolysis. Ketone body metabolism also depends on insulin action, as insulin reduces ketone body concentrations and influences protein metabolism. It increases nitrogen retention, facilitates the transport of amino acids into cells and increases the synthesis of proteins. Insulin also inhibits protein breakdown and is involved in cellular growth and proliferation. On the other hand, defects in the intracellular signaling pathways of insulin may cause several disturbances in human metabolism, resulting in several chronic diseases. Insulin resistance, also known as impaired insulin sensitivity, is due to the decreased reaction of insulin signaling for glucose levels, seen when glucose use in response to an adequate concentration of insulin is impaired. Insulin resistance may cause, for example, increased plasma insulin levels. That state, called hyperinsulinemia, impairs metabolic processes and is observed in patients with type 2 diabetes mellitus and obesity. Hyperinsulinemia may increase the risk of initiation, progression and metastasis of several cancers and may cause poor cancer outcomes. Insulin resistance is a health problem worldwide; therefore, mechanisms of insulin resistance, causes and types of insulin resistance and strategies against insulin resistance are described in this review. Attention is also paid to factors that are associated with the development of insulin resistance, the main and characteristic symptoms of particular syndromes, plus other aspects of severe insulin resistance. This review mainly focuses on the description and analysis of changes in cells due to insulin resistance.

Silymarin Reduced Insulin Resistance in Non-Diabetic Women with Obesity

Silymarin has ameliorated obesity, type 2 diabetes (T2DM), and insulin resistance (IR) in combination with standard therapy, diet, or exercise in recent studies. Obesity and IR are the main risk factors for developing T2DM and other metabolic disorders. Today, there is a need for new strategies to target IR in patients with these metabolic diseases. In the present longitudinal study, a group of non-diabetic insulin-resistant women with type 1 and type 2 obesity were given silymarin for 12 weeks, with no change in habitual diet and physical activity. We used the Homeostatic Model Assessment for Insulin Resistance Index (HOMA-IR) to determine IR at baseline and after silymarin treatment (t = 12 weeks). We obtained five timepoint oral glucose tolerance tests, and other biochemical and clinical parameters were analyzed before and after treatment. Treatment with silymarin alone significantly reduced mean fasting plasma glucose (FPG) and HOMA-IR levels at 12 weeks compared to baseline values (p < 0.05). Mean fasting plasma insulin (FPI), total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (Tg), indirect bilirubin, and C-reactive protein (CRP) levels decreased compared to baseline values, although changes were non-significant. The overall results suggest that silymarin may offer a therapeutic alternative to improve IR in non-diabetic individuals with obesity. Further clinical trials are needed in this type of patient to strengthen the results of this study.

Mapping the landscape of research on insulin resistance: a visualization analysis of randomized clinical trials

BACKGROUND

Insulin resistance, a condition in which cells do not respond adequately to insulin, plays a crucial role in diabetes and related metabolic disorders. Randomized clinical trials (RCTs) explore interventions to manage insulin resistance, contributing to evidence-based medical progress. The current study aimed to analyze the global research landscape and trends in RCTs targeting insulin resistance.

METHODS

This study used bibliometric analysis and data visualization to examine RCT publications on insulin resistance from 2003 to 2022. The Scopus database was used due to its comprehensive coverage. The search strategy involved combining terms related to insulin resistance with RCT-related terms. The search query was validated, and core bibliometric indicators were used to analyze publication growth, origin, productivity, quality, and citations.

RESULTS

Between 2003 and 2022, 1077 RCT-focused publications on insulin resistance were identified from a pool of 24,932 related articles. The growth followed two phases, with a significant increase after 2008. The USA (n = 308; 28.60%), Iran (n = 165; 15.32%), China (n = 110; 10.21%), and the UK (n = 92; 8.54%) were the main contributors. The active institutions included Tehran University of Medical Sciences (n = 38; 3.53%) and Harvard Medical School (n = 31; 2.88%). Prominent funding agencies include the National Institutes of Health (n = 88; 8.17%) and the National Institute of Diabetes and Digestive and Kidney Diseases (n = 86; 7.99%). The top journals included the American Journal of Clinical Nutrition (n = 44; 4.09%) and Diabetes Care (n = 35; 3.25%). Co-occurrence analysis revealed three clusters addressing "utilizing lipid panels as indicators of insulin resistance," "analyzing the impact of diet composition and physical activity on insulin sensitivity among obese individuals," and "exploring insulin resistance in cases of polycystic ovary syndrome."

CONCLUSIONS

This comprehensive bibliometric analysis highlights the global research landscape and trends in RCTs targeting insulin resistance. Research on lipid panels, diet impact, and insulin resistance in patients with polycystic ovary syndrome will continue to be a hotspot. The findings offer valuable information on research priorities, international collaborations, and impactful publications. This study provides a foundation for future directorial investigations in this critical area of metabolic health.

Impact of different severity hyperglycemia on erythrocyte rheological properties1

BACKGROUND

The triad "insulin resistance, prediabetes, diabetes" is three independent neologies with characteristic features and development. In addition, each are characterized by progression and the possibility of transition from one form to other. Due to the fact that diabetes is one of the common diseases associated with high rates of disability, it is necessary to improve diagnostic methods and educational regimens for successful prevention and treatment of the disease.

OBJECTIVE

We investigated Band 3 protein (B3p) level, osmotic resistance of erythrocytes, the total antioxidant activity (TAA) of blood serum, level of HbA1 in group patients with insulin resistance (IR), prediabetes, and Type 2 Diabetes Mellitus (T2DM) and comparative with health control group.

METHODS

We used original, accurate research methods that measure the essence of the studied quantities.

RESULTS

Disruptions of glucose and insulin homeostasis ay lead to the initiation of oxidative stress (in our study demonstrated by a decrease of TAA of blood serum) increased redox-sensitive PTP activity and aberrant band 3 phosphorylation, potentially leading to reduced erythrocyte deformability. At the same time glycation of Hb during T2DM may affect its cross-link with membrane proteins, in particular with B3p, and although appears to limit its cross-linking and decrease its clusterization ability, induces alterations in the cytoskeletal matrix, and thereby decrease erythrocytes' osmotic resistance making them more susceptible to hemolysis.

CONCLUSIONS

The osmotic resistance of the erythrocytes can be used as a sensitive marker for the detection of the early stages of hyperglycemia (prediabetes). This set of clinical trials will make it possible to identify diseases that make up the triad at an early stage. Early detection of disorders and continued research in this direction will help in the development of a diagnostic scheme for the prevention of such patients. Based on our data, research into anti-oxidation drugs is very important. With the help of the array of studies described in the article and antioxidant treatment, the likelihood of successful treatment will increase.

An update on galanin and spexin and their potential for the treatment of type 2 diabetes and related metabolic disorders

Spexin (SPX) and galanin (GAL) are two neuropeptides widely expressed in the central nervous system as well as within peripheral tissues in humans and other species. SPX and GAL mediate their biological actions through binding and activation of galanin receptors (GALR), namely GALR1, GALR2 and GLAR3. GAL appears to trigger all three galanin receptors, whereas SPX interacts more specifically with GALR2 and GLAR3. Whilst the biological effects of GAL have been well-described over the years, in-depth knowledge of physiological action profile of SPX is still in its preliminary stages. However, it is recognised that both peptides play a significant role in modulating overall energy homeostasis, suggesting possible therapeutically exploitable benefits in diseases such as obesity and type 2 diabetes mellitus. Accordingly, although both peptides activate GALR's, it appears GAL may be more useful for the treatment of eating disorders such as anorexia and bulimia, whereas SPX may find therapeutic application for obesity and obesity-driven forms of diabetes. This short narrative review aims to provide an up-to-date account of SPX and GAL biology together with putative approaches on exploiting these peptides for the treatment of metabolic disorders.

Triglyceride glucose index as a predictor of mortality in middle-aged and elderly patients with type 2 diabetes in the US

Despite a wealth of research linking the triglyceride glucose index (TyG index) to metabolic diseases. However, little evidence links the TyG index to all-cause or CVD mortality in middle-aged and elderly individuals with type 2 diabetes (T2D). This study analyzed data from 2998 patients with T2D who participated in the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2018. The TyG index and mortality in middle-aged and elderly T2D patients were investigated using Cox regression models. The nonlinear association between the TyG index and mortality can be understood with the help of a restricted cubic spline (RCS). During a median follow-up period of 82 months, 883 fatalities were observed from all causes and 265 from CVD. The TyG index was found to have a U-shaped relationship with all-cause and CVD mortality in T2D, with cutoffs of 8.95 and 9, respectively, according to the RCS. After controlling for other factors, an increase of 1 unit in the TyG index was related to an increase of 33% in all-cause mortality and 50% in CVD mortality when TyG was ≥ 8.95 and 9. When TyG < 8.95 and 9, with the change in the TyG index, the change in all-cause and CVD death was insignificant. Patients with T2D who are middle-aged or older, especially elderly patients, have higher TyG levels associated with increased mortality. In middle-aged and elderly patients with T2D, the TyG index may predict the probability of death from any cause and death from CVD.

Continuous glucose monitoring in a healthy population: understanding the post-prandial glycemic response in individuals without diabetes mellitus

Continuous glucose monitoring has become a common adjunct in the management of Diabetes Mellitus. However, there has been a recent trend among individuals without diabetes using these devices as a means of monitoring their health. The increased visibility of glucose data has allowed users to study the effect lifestyle has upon post-prandial glucose levels. Although post-prandial hyperglycemia is well understood in the setting of diabetes, its impact in individuals without diabetes is less well defined. This article reviews the factors which contribute to post-prandial hyperglycemia in individuals without diabetes and how the data obtained from continuous glucose monitoring can be used to improve an individual's metabolic health.

Mechanisms of Oxidative Stress in Metabolic Syndrome

Metabolic syndrome is a cluster of conditions associated with the risk of diabetes mellitus type 2 and cardiovascular diseases (CVDs). Metabolic syndrome is closely related to obesity. Increased adiposity promotes inflammation and oxidative stress, which are precursors of various complications involving metabolic syndrome components, namely insulin resistance, hypertension, and hyperlipidemia. An increasing number of studies confirm the importance of oxidative stress and chronic inflammation in the etiology of metabolic syndrome. However, few studies have reviewed the mechanisms underlying the role of oxidative stress in contributing to metabolic syndrome. In this review, we highlight mechanisms by which reactive oxygen species (ROS) increase mitochondrial dysfunction, protein damage, lipid peroxidation, and impair antioxidant function in metabolic syndrome. Biomarkers of oxidative stress can be used in disease diagnosis and evaluation of severity.

Specific RNA m6A modification sites in bone marrow mesenchymal stem cells from the jawbone marrow of type 2 diabetes patients with dental implant failure

The failure rate of dental implantation in patients with well-controlled type 2 diabetes mellitus (T2DM) is higher than that in non-diabetic patients. This due, in part, to the impaired function of bone marrow mesenchymal stem cells (BMSCs) from the jawbone marrow of T2DM patients (DM-BMSCs), limiting implant osseointegration. RNA N6-methyladenine (m6A) is important for BMSC function and diabetes regulation. However, it remains unclear how to best regulate m6A modifications in DM-BMSCs to enhance function. Based on the "m6A site methylation stoichiometry" of m6A single nucleotide arrays, we identified 834 differential m6A-methylated genes in DM-BMSCs compared with normal-BMSCs (N-BMSCs), including 43 and 790 m6A hypermethylated and hypomethylated genes, respectively, and 1 gene containing hyper- and hypomethylated m6A sites. Differential m6A hypermethylated sites were primarily distributed in the coding sequence, while hypomethylated sites were mainly in the 3'-untranslated region. The largest and smallest proportions of m6A-methylated genes were on chromosome 1 and 21, respectively. MazF-PCR and real-time RT-PCR results for the validation of erythrocyte membrane protein band 4.1 like 3, activity-dependent neuroprotector homeobox (ADNP), growth differentiation factor 11 (GDF11), and regulator of G protein signalling 2 agree with m6A single nucleotide array results; ADNP and GDF11 mRNA expression decreased in DM-BMSCs. Furthermore, gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses suggested that most of these genes were enriched in metabolic processes. This study reveals the differential m6A sites of DM-BMSCs compared with N-BMSCs and identifies candidate target genes to enhance BMSC function and improve implantation success in T2DM patients.

The effects of L-carnitine supplementation on glycemic markers in adults: A systematic review and dose-response meta-analysis

Background and aims

Hyperglycemia and insulin resistance are concerns today worldwide. Recently, L-carnitine supplementation has been suggested as an effective adjunctive therapy in glycemic control. Therefore, it seems important to investigate its effect on glycemic markers.

Methods

PubMed, Scopus, Web of Science, and the Cochrane databases were searched in October 2022 for prospective studies on the effects of L-carnitine supplementation on glycemic markers. Inclusion criteria included adult participants and taking oral L-carnitine supplements for at least seven days. The pooled weighted mean difference (WMD) was calculated using a random-effects model.

Results

We included the 41 randomized controlled trials (RCTs) (n = 2900) with 44 effect sizes in this study. In the pooled analysis; L-carnitine supplementation had a significant effect on fasting blood glucose (FBG) (mg/dl) [WMD = -3.22 mg/dl; 95% CI, -5.21 to -1.23; p = 0.002; I ² = 88.6%, p < 0.001], hemoglobin A1c (HbA1c) (%) [WMD = -0.27%; 95% CI, -0.47 to -0.07; p = 0.007; I ² = 90.1%, p < 0.001] and homeostasis model assessment-estimate insulin resistance (HOMA-IR) [WMD = -0.73; 95% CI, -1.21 to -0.25; p = 0.003; I ² = 98.2%, p < 0.001] in the intervention compared to the control group. L-carnitine supplementation had a reducing effect on baseline FBG ≥100 mg/dl, trial duration ≥12 weeks, intervention dose ≥2 g/day, participants with overweight and obesity (baseline BMI 25-29.9 and >30 kg/m²), and diabetic patients. Also, L-carnitine significantly affected insulin (pmol/l), HOMA-IR (%), and HbA1c (%) in trial duration ≥12 weeks, intervention dose ≥2 g/day, and participants with obesity (baseline BMI >30 kg/m²). It also had a reducing effect on HOMA-IR in diabetic patients, non-diabetic patients, and just diabetic patients for insulin, and HbA1c. There was a significant nonlinear relationship between the duration of intervention and changes in FBG, HbA1c, and HOMA-IR. In addition, there was a significant nonlinear relationship between dose (≥2 g/day) and changes in insulin, as well as a significant linear relationship between the duration (weeks) (coefficients = -16.45, p = 0.004) of intervention and changes in HbA1C.

Conclusions

L-carnitine could reduce the levels of FBG, HbA1c, and HOMA-IR.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42022358692.

Arctigenin mitigates insulin resistance by modulating the IRS2/GLUT4 pathway via TLR4 in type 2 diabetes mellitus mice

Arctigenin (AR), extracted from Arctium lappa L. (Burdock), is a folk herbal medicine used to treat diabetes. However, its mechanism of action has remained elusive. In this study, type 2 diabetes mellitus (T2DM) mice received AR orally for 10 weeks to evaluate its therapeutic effect based on changes in glucose and lipid metabolism, histological examination of target tissues, and liver immunohistochemistry. Furthermore, HepG2 insulin-resistant cells were established to verify the mechanism of AR against diabetes. The results showed that AR treatment reduced blood glucose and lipid levels, reversing liver as well as pancreas tissue damage in T2DM mice. AR reduced the levels of pro-inflammatory cytokines in the serum of T2DM mice, as well as those in insulin-resistant HepG2 cell supernatants, while increasing interleukin-10 (IL-10) levels. The levels of p-p65, phospho-c-Jun N-terminal kinase (p-JNK), induced nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) were reduced in the liver tissue of T2DM mice, accompanied by an upregulation of glucose transporter 4 (GLUT4) and insulin receptor substrate 2 (IRS-2). In vitro studies further showed that AR downregulated toll-like receptor 4-mediated inflammation, while upregulating insulin pathway-related proteins and ultimately improving glucose uptake in insulin-resistant HepG2 cells. In conclusion, AR protected mice from insulin resistance, and its therapeutic effect was likely associated with inhibition of toll-like receptor 4 inflammatory signaling to reactivate IRS-2/GLUT4.

Glycation of Tie-2 Inhibits Angiopoietin-1 Signaling Activation and Angiopoietin-1-Induced Angiogenesis

The impairment of the angiopoietin-1 (Ang-1)/Tie-2 signaling pathway has been thought to play a critical role in diabetic complications. However, the underlying mechanisms remain unclear. The present study aims to investigate the effects of Tie-2 glycation on Ang-1 signaling activation and Ang-1-induced angiogenesis. We identified that Tie-2 was modified by advanced glycation end products (AGEs) in aortae derived from high fat diet (HFD)-fed mice and in methylglyoxal (MGO)-treated human umbilical vein endothelial cells (HUVECs). MGO-induced Tie-2 glycation significantly inhibited Ang-1-evoked Tie-2 and Akt phosphorylation and Ang-1-regulated endothelial cell migration and tube formation, whereas the blockade of AGE formation by aminoguanidine remarkably rescued Ang-1 signaling activation and Ang-1-induced angiogenesis in vitro. Furthermore, MGO treatment markedly increased AGE cross-linking of Tie-2 in cultured aortae ex vivo and MGO-induced Tie-2 glycation also significantly decreased Ang-1-induced vessel outgrow from aortic rings. Collectively, these data suggest that Tie-2 may be modified by AGEs in diabetes mellitus and that Tie-2 glycation inhibits Ang-1 signaling activation and Ang-1-induced angiogenesis. This may provide a novel mechanism for Ang-1/Tie-2 signal dysfunction and angiogenesis failure in diabetic ischaemic diseases.

Diverse impact of N-acetylcysteine or alpha-lipoic acid supplementation during high-fat diet regime on fatty acid transporters in visceral and subcutaneous adipose tissue

PURPOSE

Adipose tissue's (AT) structural changes accompanying obesity may alter lipid transport protein expression and, thus, the fatty acids (FAs) transport and lipid balance of the body. Metabolic abnormalities within AT contribute to the elevated production of reactive oxygen species and increased oxidative/nitrosative stress. Although compounds such as N-acetylcysteine (NAC) and α-lipoic acid (ALA), which restore redox homeostasis, may improve lipid metabolism in AT, the mechanism of action of these antioxidants on lipid metabolism in AT is still unknown. This study aimed to examine the impact of NAC and ALA on the level and FA composition of the lipid fractions, and the expression of FA transporters in the visceral and subcutaneous AT of high-fat diet-fed rats.

MATERIALS AND METHODS

Male Wistar rats were randomly divided into four groups. The mRNA levels and protein expression of FA transporters were assessed using real-time PCR and Western Blot analyses. The collected samples were subjected to histological evaluation. The level of lipids (FFA, DAG, and TAG) was measured using gas-liquid chromatography.

RESULTS

We found that antioxidants affect FA transporter expressions at both the transcript and protein levels, and, therefore, they promote changes in AT's lipid pools. One of the most remarkable findings of our research is that different antioxidant molecules may have a varying impact on AT phenotype.

CONCLUSION

NAC and ALA exert different influences on AT, which is reflected in histopathological images, FA transport proteins expression patterns, or even the lipid storage capacity of adipocytes.