Insulin action and resistance in obesity and type 2 diabetes

Neuropathological links between T2DM and LOAD: systematic review and meta-analysis

Recent decades have described parallel neuropathological mechanisms increasing the risk for developing late-onset Alzheimer's dementia (LOAD) in type 2 diabetes mellitus (T2DM); however, still little is known of the role of diabetic encephalopathy and brain atrophy in LOAD. The aim of this systematic review is to provide a comprehensive view on diabetic encephalopathy/cerebral atrophy, taking into account neuroimaging data, neuropathology, metabolic and endocrine mechanisms, amyloid formation, brain perfusion impairments, neuroimmunology, and inflammasome activation. Key switches were identified, to further meta-analyze genomic candidate loci and epigenetic modifications. For the qualitative meta-analysis of genomic bases extracted, human linkage studies were examined; for epigenetic mechanisms, data from both human and animal studies are described. For the systematic review of pathophysiological mechanisms, 1,259 publications were evaluated and 93 gene loci extracted for candidate risk linkages. Sixty-six publications were evaluated for genomic association and descriptions of epigenomic modifications. Overall accumulated results highlight the insulin signaling system, vascular markers, inflammation and inflammasome pathways, amylin interactions, and glycosylation mechanisms. The protocol was registered with PROSPERO (ID: CRD42023440535).

Effects of a protein kinase C epsilon inhibitor on insulin signalling in lipid-treated HepG2 hepatocytes and glucose tolerance in fat-fed mice

AIMS

Protein kinase C epsilon (PKCε) plays a causative role in the development of glucose intolerance, and is a potential target for the treatment of type 2 diabetes. Here, we examined the effects of the PKCε inhibitor CIDD-0150612 (CP612) on insulin action in palmitate-treated HepG2 hepatocytes in vitro and on glucose homeostasis in fat-fed mice in vivo.

METHODS

HepG2 cells were treated with palmitate and CP612 and stimulated with insulin. Insulin signalling was examined by immunoblotting and glucose incorporation into glycogen was measured using glucose tracer. Mice were fed a high-fat diet and treated with CP612 prior to glucose tolerance tests and tissue harvest. Proteomic analysis of liver was carried out by mass spectrometry.

RESULTS

CP612 promoted Akt phosphorylation in a highly insulin-dependent manner and reversed the inhibition of insulin-stimulated Akt phosphorylation and glucose incorporation into glycogen by palmitate. Fat-fed mice treated with CP612 had reduced fat mass, but not lean mass, compared with vehicle-treated littermates. Mice treated acutely with CP612 exhibited elevated fasting blood glucose. However, mice studied 24h after the last dose had lower fasting glucose and improved glucose tolerance with a lower insulin excursion. Proteomic analysis of liver from CP612-treated fat-fed mice indicated a reduction in gluconeogenic gene expression and decreased phosphorylation of the transcription factor Foxk1.

CONCLUSIONS

The PKCε inhibitor CP612 had beneficial effects on insulin action in hepatocytes and on fat mass and glucose homeostasis in mice. Because certain effects were not previously observed in genetically PKCε-deficient mice, off-target effects may be partly responsible.

Metabolic dysfunction-associated steatotic liver disease: A sexually dimorphic disease and breast and gynecological cancer

Metabolic dysfunction-associated steatotic liver disease (MASLD) has become a global public health and economic burden worldwide in the past few decades. Epidemiological studies have shown that MASLD is a multisystem disease that is associated not only with liver-related complications but also with an increased risk of developing extrahepatic cancers. MASLD is a sexually dimorphic disease with sex hormones playing an important role in the development and progression of MASLD, especially by the levels and ratios of circulating estrogens and androgens. MASLD is associated with hormone-sensitive cancers including breast and gynecological cancer. The risk of breast and gynecological cancer is elevated in individuals with MASLD driven by shared metabolic risk factors including obesity and insulin resistance. Multiple potential mechanisms underline these associations including metabolic dysfunction, gut dysbiosis, chronic inflammation and dysregulated release of hepatokines. However, the effect of hormone therapy including hormone replacement therapy and anti-estrogen treatment on MASLD and female-specific cancers remains debatable at this time. This synopsis will review the associations between MASLD and breast and gynecological cancer, their underlying mechanisms, implications of hormonal therapies, and their future directions.

Neurophysiological mechanisms of electroacupuncture in regulating pancreatic function and adipose tissue expansion

BACKGROUND

Electroacupuncture (EA) has been recognized for its beneficial effects on glucolipid metabolism, potentially through the regulation of sensory nerve coordination. The expandability of peripancreatic adipose tissue (PAT) is implicated in the transition from obesity to type 2 diabetes mellitus (T2DM). However, the specific pancreatic responses to EA require further elucidation.

AIM

To investigate the influence of EA on pancreatic glucolipid reduction level in a high-fat diet (HFD) rat model.

METHODS

To delineate the precise pathway through which EA mediates interactions between PAT and islets, we assessed the expression levels of NGF, TRPV1, insulin, as well as other proteins in the pancreas and PAT. This approach enabled us to identify the acupoints that are most conducive to optimizing glycolipid metabolism.

RESULTS

The ST25, LI11 and ST37 groups attenuated HFD-induced obesity and insulin resistance (IR) to distinct degrees, with ST25 group having the greatest effect. EA at ST25 was found to modify the local regulatory influence of PAT on the pancreatic intrinsic nervous system. Specifically, EA at ST25 obviously activated the TRPV1-CGRP-islet beta cell pathway, contributing to the relief of glucolipid metabolic stress. The beneficial effects were abrogated following the chemical silencing of TRPV1 sensory afferents, confirming their indispensable role in EA-mediated regulation of islet and PAT function. Furthermore, in TRPV1 knockout mice, a reduction in PAT inflammation was observed, along with the recovery of islet beta cell function. EA at LI11 and ST37 demonstrated anti-inflammatory properties and helped ameliorate IR.

CONCLUSION

The PAT ecological niche influenced the progression from obesity to T2DM through various immunometabolic pathways. EA at ST25 could regulate glucolipid metabolism via the TRPV1-CGRP-islet beta cell pathway.

Establishment and Characterization of Hepatocyte Line from Turbot (Scophthalmus maximus L.) and Its Application in the Study of Glucose Metabolism

The present study was to establish a hepatocyte line and investigate its role in glucose metabolism. A continuous cell line, THL (turbot hepatocyte line), was established from the liver tissue of turbot (Scophthalmus maximus L.). It has been successfully passaged more than 60 generations. The THL cells showed an epithelial-like morphology and the normal chromosome number was 44. Different methods were used to identify the hepatocytes. Periodic acid-Schiff (PAS) staining for THL cells was positive, and two key functional proteins of hepatocytes, cytokeratin- 18 (CK- 18) and albumin (ALB), were detected in THL cells. The results of CCK- 8 indicated that a medium containing 15 mM glucose showed optimal cell viability of THL. Conversely, elevating glucose concentrations beyond 50 mM markedly impaired THL cell viability. Western blot and qRT-PCR were employed to assess the gene and protein expression in cells treated with varying concentrations of glucose. The results of cells incubated with 0 mM, 15 mM, and 50 mM glucose concentrations showed that compared with the 0 mM glucose group, 15 mM glucose could increase the gene expression of glucokinase (gk) and decrease the gene expression of cytosolic phosphoenolpyruvate carboxykinase (cpepck), mitochondrial phosphoenolpyruvate (mpepck), glucose- 6-phosphatase 1 (g6pase1), forkhead box o1 (foxo1), and glucose-regulated protein 78 (grp78). Compared to 15 mM glucose treatment, the expression of gk in the 50 mM group was significantly decreased, but the expression of cpepck, mpepck, g6pase1, foxo1, and grp78 was significantly increased. Moreover, the protein expression of FoxO1 and GRP78 in 50 mM treatment group was significantly increased compared to that in the15 mM group. In the present study, it was found that excessive glucose level can activate the pathways of FoxO1-mediated gluconeogenesis and GRP78-mediated endoplasmic reticulum stress and reduce the glycolytic pathway, thus disrupting the glucose homeostasis in hepatocytes.

Triglyceride-glucose index and triglyceride-to-high-density lipoprotein cholesterol ratio in predicting severity of acute pancreatitis: a cross-sectional clinical study

BACKGROUND

The aim of this study is to investigate the correlation of triglyceride-glucose (TyG) index and triglyceride-to-high-density lipoprotein cholesterol (TG/HDL-C) ratio with acute pancreatitis (AP), and to compare the predictive value of the two indexes for severe AP (SAP).

METHODS

This study was a clinical cross-sectional study. Spearman's correlation, logistic regression analysis and receiver operating characteristic (ROC) curves were used to investigate the relationship between the TyG index and TG/HDL-C ratio with SAP.

RESULTS

Of the 311 enrolled AP patients, the mean age was 62.59 ± 9.03 years, and 131 (42.12%) were male. A total of 34 (10.93%) patients met the diagnostic criteria for SAP. The results of Spearman's correlation showed that TyG index (Spearman rho = 0.262; p < 0.001), TG/HDL-C ratio (Spearman rho = 0.206; p < 0.001) were associated with SAP. Logistic regression analysis showed that TyG index was independently and positively correlated with SAP [odds ratio (OR), 4.311; 95% confidence interval (CI), 1.222-15.208; p = 0.023]. However, this association was not further confirmed on TG/HDL-C ratio (OR, 2.530; 95% CI, 0.883-7.251; p = 0.084). According to the ROC curve analysis, the area under the curve (AUC) for TyG index was 0.712 (p < 0.001), and the AUC for TG/HDL-C ratio was 0.691 (p < 0.001).

CONCLUSIONS

TyG index and TG/HDL-C ratio have different diagnostic values in AP patients. And the TyG index may be a more useful auxiliary tool for predicting SAP.

Liver lipid metabolism, oxidative stress, and inflammation in glutamine-supplemented ob/ob mice

Glutamine availability may be reduced in chronic diseases, such as type 2 diabetes mellitus (T2DM)-induced by obesity. Herein, the antioxidant, anti-inflammatory and lipid metabolism effects of chronic oral glutamine supplementation in its free and dipeptide form were assessed in ob/ob mice. Adult male C57BL/6J ob/ob mice were supplemented with L-alanyl-L-glutamine (DIP) or free L-glutamine (GLN) in the drinking water for 40 days, whilst C57BL/6J Wild-type lean (WT) and control ob/ob mice (CTRL) received fresh water only. Plasma and tissue (skeletal muscle and liver) glutamine levels, and insulin resistance parameters (e.g., GTT, ITT, insulin) were determined. Oxidative stress (e.g., GSH system, Nrf2 translocation), inflammatory (e.g., NFkB translocation, TNF-α gene expression) and lipid metabolism parameters (e.g., plasma and liver triglyceride levels, SRBP-1, FAS, ACC, and ChRBP gene expression) were also analyzed. CTRL ob/ob mice showed lower glutamine levels in plasma and tissue, as well as increased insulin resistance and fat in the liver. Conversely, chronic DIP supplementation restored glutamine levels in plasma and tissues, improved glucose homeostasis and reduced plasma and liver lipid levels. Also, Nrf2 restoration, reduced NFkB translocation, and lower TNF-α gene expression was observed in the DIP group. Interestingly, chronic free GLN only increased muscle glutamine stores but reduced overall insulin resistance, and attenuated plasma and liver lipid metabolic biomarkers. The results presented herein indicate that restoration of body glutamine levels reduces oxidative stress and inflammation in obese and T2DM ob/ob mice. This effect attenuated hepatic lipid metabolic changes observed in obesity.

Pathophysiological hallmarks in type 2 diabetes heterogeneity (review)

The mechanistic complexity in type 2 diabetes (T2DM) is primarily responsible for the degrees of heterogeneity and development of complications. A complex mode of interactions between different pathophysiological events and diabetogenic environmental factors support for the genesis of diabetes heterogeneity both in phenotypic and clinical contexts. The currently used diabetes classification strategies suffer from several inconsistencies that cannot fully capture the inherent heterogeneity among the diabetes patients. To effectively address this pathobiological and heterogeneity-related issue in diabetes research, the current review proposes nine pathophysiological hallmarks of T2DM that aims to mechanistically explain complexities of diabetes associated pathophysiological events and their underlying features. These pathophysiological hallmarks are pancreatic beta cell dysfunction, insulin sensitivity, insulin resistance, obesity, aging, subclinical inflammation, metabolic dysregulation, prothrombotic state induction and hypertension. Detail knowledge of these pathophysiological hallmarks with their key molecular mediators, influencing factors, clinical biomarkers and clinical assessment methodologies will greatly support precision medicine approaches in diabetes including patient stratification, subtype diagnosis and treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13340-024-00783-w.

Association Between Circulating Gremlin 2 and β-Cell Function Among Participants With Prediabetes and Type 2 Diabetes

AIM

Circulating Gremlin 2 (Grem2) has recently been linked to human obesity, but its role in type 2 diabetes (T2D) remains unclear. This study aims to explore the association of circulating Grem2 with β-cell function.

METHODS

A post hoc analysis was conducted using data from three clinical trials, in which all participants underwent the oral glucose tolerance test (OGTT). Circulating Grem2 levels were measured at 0, 1, and 2 h during the OGTT. In Trial 1, Grem2 levels were compared between participants with T2D (n = 59) and without T2D (n = 119). We further examined changes in Grem2 levels in response to oral antidiabetic drugs in participants with T2D in Trial 2 (n = 67) and calorie restriction in participants with prediabetes in Trial 3 (n = 231). The relationship between Grem2 levels and β-cell function was analyzed across all trials.

RESULTS

Fasting and 1-h Grem2 levels were lower in participants with T2D compared with those without T2D (728 ± 25 vs. 649 ± 31 pg/mL, p = 0.020; 631 ± 26 vs. 537 ± 31 pg/mL, p = 0.007). Fasting Grem2 levels were restored after antidiabetic treatment (550 ± 12 vs. 575 ± 12 pg/mL, p = 0.019), and 1-h Grem2 levels increased following calorie restriction (1118 ± 89 vs. 1144 ± 90 vs. 1253 ± 89 pg/mL, p for trend = 0.002). The 1-h Grem2 levels were positively associated with β-cell function assessed by the oral disposition index and HOMA-β.

CONCLUSION

Reduced circulating Grem2 levels are associated with impaired β-cell function in T2D, and could be restored through antidiabetic interventions.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01959984, NCT01758471, NCT03856762.

Effects of Dioscorea opposita polysaccharides on insulin resistance and gut microbiota in high-fat-diet induced type 2 diabetic rats

This study investigates the effects Dioscorea opposita polysaccharides (DOP) on insulin resistance, lipid metabolism, oxidative stress, and intestine microbiota in high-fat-diet and streptozotocin induced type 2 diabetes (T2DM) rats. Low dose (DOP-L, 200 mg/kg BW), high dose (DOP-H, 400 mg/kg BW) and D. opposita powder (DO, 400 mg/kg BW) were oral-administrated to T2DM rats. After 6 weeks of treatment, supplementation of DOP-H and DO improved body weight and glucose/lipid metabolism-related indicators, including glucagon-like peptide 1, total cholesterol and high-density lipoprotein cholesterol. DOP-H and DO suppressed liver oxidative stress through increasing the level of superoxide dismutase, catalase, glutathione and reducing malondialdehyde. DOP attenuated the pathological change in liver, such as hepatic steatosis, and thus improved the liver function. Furthermore, the anti-diabetic effects of DOP was correlated with alterations of the gut microbiota, including an increase in Firmicutes and Bacteroidetes and a decrease in Actinobacteria and Proteobacteria, which promoted a healthier gut environment. Further analysis of short-chain fatty acids and metabolites provided evidences of DOP's regulatory effects on cecal contents in T2DM rats. Therefore, DOP-H present decent effects on T2DM, suggesting that DOP can ameliorate the insulin resistance and restore blood lipid level of T2DM rats with high-fat-diet by regulating intestinal microbiota.

Treadmill Exercise Modulates the Leptin/LepR/GSK-3β Signalling Pathway to Improve Leptin Sensitivity and Alleviate Neuroinflammation in High-Fat Diet-Fed APP/PS1 Mice

Neuroinflammation plays a critical role in the development of Alzheimer's disease (AD) and is closely associated with obesity. In AD, the fat cell-secreted protein leptin crosses the blood-brain barrier and protects against nerve damage. However, obesity may induce leptin resistance, reduce leptin sensitivity, stimulate excessive glial cell activation, promote inflammatory factor production and exacerbate brain inflammation. Unfortunately, the mechanism of interaction among high-fat diets, obesity, neuroinflammation and neurodegenerative diseases remains unclear. We investigated the changes in neuroinflammation and leptin sensitivity in the brains of wild-type and high-fat-diet-fed APP/PS1 transgenic mice. We explored the effects of treadmill exercise for 12 weeks on the leptin/LepR/GSK-3β signalling pathway and memory. The body weights of the high-fat-diet-fed mice increased, and elevated levels of markers for leptin resistance, including suppressor of signalling 3 (SOCS3), protein tyrosine phosphatase 1B (PTP1B) and proinflammatory factors such as tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6), were observed. After 12 weeks of aerobic exercise, the leptin mRNA and protein levels increased, GSK-3β protein expression decreased and the mean fluorescence intensities of brain microglial (IBA-1) and neuron markers (NeuN) decreased, indicating that exercise may activate the leptin/LepR/GSK-3β signalling pathway, reducing glial cell activation and inflammation. Our study revealed that obesity induces and exacerbates the AD-related neuroinflammatory response. Aerobic exercise activates the leptin/LepR/GSK-3β pathway to relieve neuroinflammation and protect nerve cells, alleviating AD-associated memory loss. These promising outcomes could inform the development of nondrug-based aerobic exercise interventions for the treatment of AD and associated cognitive disorders.

Triglyceride-glucose index: a potent predictor of metabolic risk factors and eating behavior patterns among obese individuals

BACKGROUND

The strong potential of triglyceride to glucose index (TyG) in prediction of metabolic abnormalities is well identified in numerous disease including diabetes, metabolic syndrome and kidney disorders. However, no study is available to assess its validity and association with metabolic phenotype among obese individuals. In the current study, we aimed to evaluate the TyG index, its validity and association with metabolic parameters among obese individuals.

METHODS AND MATERIALS

In the current cross-sectional study, 300 obese individuals were enrolled. Their demographic, anthropometric measurements were done and laboratory parameters including serum lipids, glycemic markers and insulin resistance were evaluated. Blood pressure was also measured with standard methods. The TyG index was calculated as the ln (fasting triglyceride level [mg/dL] × fasting glucose level [mg/dL]/2). Eating pattern was measured with three factor eating behavior questionnaire (TFEQ). Receiver operator characteristic curve was used to assess the TyG validity.

RESULTS

Subjects at the higher TyG tertile had higher waist o hip ratio (WHR) and eating disorder compared with lowest tertiles. Also, those at the highest tertiles had significantly higher total cholesterol (TC), triglyceride (TG), and fasting blood sugar (FBS), and lower high density lipoprotein cholesterol (HDL). According to the ROC curve analysis for various metabolic parameters, TyG demonstrated the highest area under curve (AUC) value of 0.838 compared with other metabolic parameters in identification of metabolic syndrome.

CONCLUSION

The current study provides valuable insights into the relationship between TyG index, metabolic parameters, and eating behaviors among obese individuals.

Pueraria Radix and Its Major Constituents Against Metabolic Diseases: Pharmacological Mechanisms and Potential Applications

Metabolic diseases (MD), a series of chronic disorders, severely decrease the quality of life for patients but also cause a heavy economic burden. The ancient Chinese herb Pueraria Radix (PR) plays an important role in curing MD. Up to now, the bioactive compounds found in PR demonstrate effective actions in treating various metabolic disorders. This paper systematically summarizes the recent research advances on the pharmacological activities of PR and its constituents, explains the underlying mechanisms of preventing and treating MD. Besides, phytochemicals, drug delivery systems, clinical application, and safety of PR have been researched, hoping to provide valuable information for the future application, development, and improvement of PR as well as MD treatment. The information about PR was collected from various sources including classic books about Chinese herbal medicine and scientific databases including Web of Science, PubMed, ScienceDirect, Springer, ACS, SCOPUS, CNKI, Google Scholar, X-MOL, and WANFANG using keywords given and terms like pharmacological and phytochemical details of this plant. The chemical constituents isolated and identified from PR, such as isoflavones including puerarin, formononetin, daidzin, daidzein, genistein, and so forth, polysaccharides, alkaloids, starch, and other components have been proved to have the effect of anti-diabetic, anti-obesity, anti-atherosclerotic, anti-osteoporotic, anti-hypertensive, anti-hyperlipidemia, and anti-nonalcoholic fatty liver disease (NAFLD) through PI3K/Akt, Nrf2/HO-1, LOX-1/ROS/Akt/eNOS, ERK1/2-Nrf2, GLP-1R, Caspase, MAPK, NF-κB, and other anti-inflammatory and anti-oxidant signaling pathways. Also, the active contents of PR have been designed as drug delivery systems to improve the therapeutic effects of MD. It provides a preclinical basis for the efficacy of PR as an effective therapeutic agent for the prevention and treatment of MD. Even so, further studies are still needed to enhance bioavailability and expand clinical application.

Distinct Roles of Common Genetic Variants and Their Contributions to Diabetes: MODY and Uncontrolled T2DM

Type 2 diabetes mellitus (T2DM) encompasses a range of clinical manifestations, with uncontrolled diabetes leading to progressive or irreversible damage to various organs. Numerous genes associated with monogenic diabetes, exhibiting classical patterns of inheritance (autosomal dominant or recessive), have been identified. Additionally, genes involved in complex diabetes, which interact with environmental factors to trigger the disease, have also been discovered. These genetic findings have raised hopes that genetic testing could enhance diagnostics, disease surveillance, treatment selection, and family counseling. However, the accurate interpretation of genetic data remains a significant challenge, as variants may not always be definitively classified as either benign or pathogenic. Research to date, however, indicates that periodic reevaluation of genetic variants in diabetes has led to more consistent findings, with biases being steadily eliminated. This has improved the interpretation of variants across diverse ethnicities. Clinical studies suggest that genetic risk information may motivate patients to adopt behaviors that promote the prevention or management of T2DM. Given that the clinical features of certain monogenic diabetes types overlap with T2DM, and considering the significant role of genetic variants in diabetes, healthcare providers caring for prediabetic patients should consider genetic testing as part of the diagnostic process. This review summarizes current knowledge of the most common genetic variants associated with T2DM, explores novel therapeutic targets, and discusses recent advancements in the pharmaceutical management of uncontrolled T2DM.

Changes in pancreatic levodopa uptake in patients with obesity and new-onset type 2 diabetes: an 18F-FDOPA PET-CT study

Introduction

Levodopa (L-3,4-dihydroxyphenylalanine)g, a dopamine precursor that circulates in the peripheral region, is involved in pancreatic glycemic control. Although previous animal studies have shown that peripheral levodopa is correlated with insulin secretion in pancreatic beta cells, the mechanism by which the pancreas uses levodopa differently in humans with obesity and type 2 diabetes remains unknown. Our study aimed to observe how the pancreas uptakes and utilizes levodopa differently under obese and diabetic conditions.

Materials and method

18F-fluoro-L-dopa positron emission tomography-computed tomography (18F-FDOPA PET-CT) was used to visualize how the human body uses levodopa under obese and diabetic conditions and presented its clinical implications. 10 patients were divided into 3 groups: 1) Group A, normal weight without type 2 diabetes; 2) Group B, obese without type 2 diabetes; and 3) Group C, obese with new-onset type 2 diabetes. All patients' lifestyle modification was conducted prior to 18F-FDOPA PET-CT, and plasma samples were collected to confirm changes in amino acid metabolites.

Results

Pancreatic levodopa uptake increased in obese patients with insulin resistance, whereas it decreased in obese patients with new-onset type 2 diabetes [standardized uptake value (SUV) mean in participants with normal weight, 2.6 ± 0.7; SUVmean in patients with obesity, 3.6 ± 0.1; SUVmean in patients with obesity and new-onset type 2 diabetes, 2.6 ± 0.1, P = 0.02].

Conclusions

This suggested that the alterations in the functional capacity of pancreatic beta cells to take up circulating levodopa are potentially linked to the insulin resistance and the pathogenesis of type 2 diabetes. The differences in the uptake values between the groups implied that pancreatic levodopa uptake could be an early indicator of type 2 diabetes.

Treatment of Type 2 Diabetes in Patients with Obesity: A Review

Type 2 diabetes and obesity have some overlapping pathophysiology. This has allowed for the creation of therapies which are highly effective in treating both conditions. Weekly subcutaneous incretin agonists are preferred agents as they provide significant improvement in glycemic parameters, weight, and other comorbidities, like heart failure and reduce major adverse cardiovascular event. Bariatric surgery continues to show the most durable benefits for patients with both type 2 diabetes mellitus and obesity and should be considered in patients who are unable to meet goals with pharmacotherapy and lifestyle.

Greater improvement in insulin sensitivity per unit weight loss associated with tirzepatide versus semaglutide: An exploratory analysis

AIMS

To explore the relationship between weight loss and insulin sensitivity in response to tirzepatide or semaglutide.

MATERIALS AND METHODS

We conducted a post hoc exploratory analysis of a 28-week, double-blind, randomized trial in people with type 2 diabetes treated with metformin, randomized to tirzepatide 15 mg, semaglutide 1 mg or placebo. We evaluated the relationship between change in body weight and change in insulin sensitivity determined from hyperinsulinemic euglycemic clamp (M value), or from mixed-meal tolerance testing (Matsuda index).

RESULTS

Tirzepatide was associated with a greater improvement than semaglutide in insulin sensitivity assessed using hyperinsulinemic euglycemic clamps (p < 0.001). With tirzepatide, improvements in insulin sensitivity were associated with percent change in weight (R = -0.656, p < 0.0001). With semaglutide, change in insulin sensitivity was less strongly correlated with percent change in weight (R = -0.268, p = 0.0820; p = 0.0242 vs. tirzepatide). In regression analyses, the slope of the relationship between change in M value and change in weight was statistically different between semaglutide and tirzepatide (p = 0.0461). These relationships were also assessed using the Matsuda index as the metric of insulin sensitivity, and using change in fat mass as the determinant of change in insulin sensitivity.

CONCLUSIONS

Improvement in insulin sensitivity was proportional to weight and fat loss, with greater strength of association with tirzepatide. In regression analysis, tirzepatide was associated with greater improvement in insulin sensitivity per unit weight loss than semaglutide. The greater improvement in insulin sensitivity following treatment with tirzepatide was not simply attributable to greater weight or fat loss.

The relationship between weight-adjusted waist index and peripheral artery disease

Background

Obesity is a significant risk factor for peripheral arterial disease (PAD). The weight-adjusted waist index (WWI) is a novel obesity metric that better reflects abdominal obesity than traditional body mass index (BMI). However, research on the relationship between WWI and PAD remains scarce.

Methods

Relevant data from the NHANES 1999-2004 were selected. Multiple logistic regression and restricted cubic spline (RCS) analyses were used to assess the relationship between WWI and the risk of PAD. Additionally, the area under the curve (AUC) of the receiver operating characteristic (ROC) was used to evaluate the predictive ability of WWI for PAD.

Results

A total of 5,686 participants were included in the study, of whom 476 had PAD and 5,210 did not. The results of multiple logistic regression showed that WWI was significantly positively associated with the risk of PAD after full adjustment for covariates (OR: 1.407, 95% CI: 1.100-1.799). Additionally, compared to the first quartile of WWI, the risk of PAD significantly increased in the second quartile (OR: 2.042, 95% CI: 1.333-3.129), third quartile (OR: 2.134, 95% CI: 1.354-3.364), and fourth quartile (OR: 2.491, 95% CI: 1.435-4.325). The ROC results showed that the AUC value for WWI was 0.697, while the AUC value for BMI was 0.520. Compared to BMI, WWI has a better predictive value for the risk of PAD.

Conclusion

There is a significant positive correlation between WWI and the risk of PAD. For individuals with high WWI, efforts should be made to reduce WWI to prevent the onset of PAD.

Integrative proteogenomic analysis identifies COL6A3-derived endotrophin as a mediator of the effect of obesity on coronary artery disease

Obesity strongly increases the risk of cardiometabolic diseases, yet the underlying mediators of this relationship are not fully understood. Given that obesity strongly influences circulating protein levels, we investigated proteins mediating the effects of obesity on coronary artery disease, stroke and type 2 diabetes. By integrating two-step proteome-wide Mendelian randomization, colocalization, epigenomics and single-cell RNA sequencing, we identified five mediators and prioritized collagen type VI α3 (COL6A3). COL6A3 levels were strongly increased by body mass index and increased coronary artery disease risk. Notably, the carboxyl terminus product of COL6A3, endotrophin, drove this effect. COL6A3 was highly expressed in disease-relevant cell types and tissues. Finally, we found that body fat reduction could reduce plasma levels of COL6A3-derived endotrophin, indicating a tractable way to modify endotrophin levels. In summary, we provide actionable insights into how circulating proteins mediate the effects of obesity on cardiometabolic diseases and prioritize endotrophin as a potential therapeutic target.

Assessment of the Potential Clinical and Economic Impact of Weight Loss in the Adult Population with Obesity and Associated Comorbidities in Spain

INTRODUCTION

Obesity and its complications are associated with high morbidity/mortality and a significant healthcare cost burden in Spain. It is therefore essential to know the potential clinical and economic benefits of reducing obesity. The objective of this study is to predict the decrease in rates of onset of potential complications associated with obesity and the cost savings after a weight loss of 15% over 10 years in Spain.

METHODS

Data were combined in an adapted version of a weight loss benefit simulation model. Sources with demographic information on the Spanish population and the distribution of obesity and type 2 diabetes mellitus (T2DM) were used to obtain the data for the model. In addition, use was made of prevalence data on obesity-associated complications from a cohort of patients with obesity in the United Kingdom (UK). These data were combined by age and sex to create a Spanish synthetic cohort.

RESULTS

The simulation showed that, for a cohort of 100,000 individuals with a body mass index (BMI) of 30-50 kg/m2, a weight loss of 15% is estimated to lead to relevant relative risk reductions in obstructive sleep apnoea (OSA) (- 56.4%), T2DM (- 39.2%), asthma (- 20.2%) and arterial hypertension (- 18.7%). The estimated overall savings were €105 million for a cohort of 100,000 individuals, mainly resulting from the decrease in T2DM and arterial hypertension (23% and 22% of the total savings at year 10, respectively), as well as osteoarthritis and chronic kidney disease (CKD) (16% and 13%, respectively).

CONCLUSIONS

Sustained weight loss could significantly reduce the burden derived from future complications associated to obesity in Spain, as well as the excess economic cost associated with its treatment.

Type 2 Diabetes Mellitus: New Pathogenetic Mechanisms, Treatment and the Most Important Complications

Type 2 diabetes mellitus (T2DM), a prevalent chronic disease affecting over 400 million people globally, is driven by genetic and environmental factors. The pathogenesis involves insulin resistance and β-cell dysfunction, mediated by mechanisms such as the dedifferentiation of β-cells, mitochondrial dysfunction, and oxidative stress. Treatment should be based on non-pharmacological therapy. Strategies such as increased physical activity, dietary modifications, cognitive-behavioral therapy are important in maintaining normal glycemia. Advanced therapies, including SGLT2 inhibitors and GLP-1 receptor agonists, complement these treatments and offer solid glycemic control, weight control, and reduced cardiovascular risk. Complications of T2DM, such as diabetic kidney disease, retinopathy, and neuropathy, underscore the need for early diagnosis and comprehensive management to improve patient outcomes and quality of life.

Optimal exercise dose on Body Mass Index (BMI) in children and adolescents with overweight and obesity: a systematic review and bayesian model-based network meta-analysis

BACKGROUND

Exercise is widely used for obesity management, but the optimal doses of exercise for improving body mass index (BMI) in children and adolescents with overweight and obesity remain unclear. This study aimed to evaluate the dose‒response effects of various exercises on BMI in children and adolescents with overweight and obesity.

METHODS

A systematic search was conducted in Web of Science (Core Collection), PubMed/MEDLINE, Embase, Scopus, and the Cochrane Library for randomized controlled trials on relevant studies, covering literature up to July 2024. Three independent reviewers assessed bias via the Cochrane risk of bias tool. The quality of evidence was assessed using Confidence in Network Meta-Analysis framework. A dose‒response network meta-analysis was used to evaluate the impact of various exercise interventions and explore dose‒response relationships. All outcomes were analyzed with the mean difference (MD) and 95% credible intervals (CrIs) calculated for combined statistics.

RESULTS

The study included 39 publications with 1,814 participants, 47.3% female and a median age of 14 years. The intervention involved six exercise modalities. High-intensity interval training demonstrated a significant reduction in BMI (MD = -1.33, 95% CrIs - 2.01 to -0.66), followed by combined exercise (MD = -1.25, 95% CrIs - 1.93 to -0.61), moderate-intensity continuous training (MD = -1.09, 95% CrIs - 1.73 to -0.45), and mixed aerobic exercise (MD = -1.05, 95% CrIs - 1.67 to -0.42). There was an 'L'-shaped nonlinear dose-response relationship between total exercise dose and BMI, with 200 METs-min/day identified as the minimum exercise dose required to achieve a clinically meaningful reduction in BMI.

CONCLUSION

Low-quality evidence indicates that HIIT, CE, MAE, and MICT improve BMI in children and adolescents with overweight and obesity, with clarified exercise doses for clinical benefit. These findings are relevant for exercise prescription and public health policy.

TRIAL REGISTRATION

CRD42024566450.

The rise of weekly insulins: addressing the challenges of type 2 diabetes care in Brazil

BACKGROUND

Type 2 diabetes mellitus (T2D) is a global health concern with a rising prevalence, particularly in Brazil. Insulin therapy plays a crucial role in managing T2D, helping to maintain glucose and energy homeostasis. Moreover, early initiation of insulin is crucial for hyperglycemic control and prevention of chronic complications. Clinical guidelines recommend initiating insulin when other treatments fail. However, several barriers may delay its initiation, contributing to therapeutic inertia and patients' non-adherence. These barriers include fear of hypoglycemia, lack of adherence, the need for glucose monitoring, the injection method of insulin administration, social rejection associated with the stigma of injections, fear of weight gain, a sense of therapeutic failure at initiation, and lack of experience among some healthcare professionals. : In this context, the development of once-weekly insulin formulations could improve initial acceptance, adherence, treatment satisfaction, and consequently, the quality of life for patients. Currently, two once-weekly insulin treatments, insulin icodec and efsitora alfa, have shown promise in clinical trials, demonstrating efficacy and safety profiles similar or better than those of daily insulin therapies.

SHORT CONCLUSION

These once-weekly insulins have the potential to emerge as landmark achievements in the evolution of insulin therapy. This narrative review aims to evaluate the role of weekly insulins in managing T2D, providing insights into the potential benefits, challenges, and opportunities associated with a new weekly insulin therapy, specially within the Brazilian context.

Association between lymphocyte to high-density lipoprotein cholesterol ratio and insulin resistance and metabolic syndrome in US adults: results from NHANES 2007-2018

BACKGROUND

Insulin resistance (IR) and metabolic syndrome (MetS) are significant global health challenges that increase the risk of various chronic diseases. The lymphocyte-to-high-density lipoprotein cholesterol ratio (LHR) has emerged as a novel inflammatory metabolic marker. The present study focused on evaluating the association between the LHR and both IR and MetS.

METHODS

We analyzed data from 14,779 adults aged ≥ 20 years from the National Health and Nutrition Examination Survey (2007-2018). To investigate the relationship between LHR and both IR and MetS, we conducted multivariable logistic regression analyses. The reliability of the results was validated through both stratified and sensitivity analyses. Furthermore, we thoroughly examined possible nonlinear associations by implementing a restricted cubic spline in conjunction with a threshold effect analysis.

RESULTS

Compared to the lowest LHR quartile, individuals in the highest quartile indicated significantly increased prevalence of IR (odds ratio = 3.72, 95% confidence intervals: 3.01-4.59) and MetS (odds ratio = 11.38, 95% confidence intervals: 8.85-14.63) in fully adjusted models. Subgroup analyses demonstrated that the association between the LHR and IR remained consistent across all subgroups, with no significant interaction effect observed. However, the association between LHR and MetS was more pronounced in female participants. Restricted cubic spline analyses revealed nonlinear associations between LHR and both IR and MetS. The threshold effect analyses identified inflection points at 0.055 for these non-linear relationships.

CONCLUSIONS

An elevated LHR was positively associated with the prevalence of IR and MetS, indicating its promising role in early screening and disease prevention through biological monitoring.

Overnutrition causes insulin resistance and metabolic disorder through increased sympathetic nervous system activity

The mechanisms underlying obesity-induced insulin resistance remain incompletely understood, as impaired cellular insulin signaling, traditionally considered the primary driver of insulin resistance, does not always accompany impaired insulin action. Overnutrition rapidly increases plasma norepinephrine (NE), suggesting overactivation of the sympathetic nervous system (SNS). However, the role of the SNS in obesity is controversial, as both increased and decreased SNS activity (SNA) have been reported. Here, we show that reducing catecholamine (CA) release from the SNS protects against overnutrition-induced insulin resistance as well as hyperglucagonemia, adipose tissue dysfunction, and fatty liver disease, as we demonstrate utilizing a mouse model of inducible and peripherally restricted deletion of tyrosine hydroxylase (th; THΔper). A key mechanism through which heightened SNA induces insulin resistance is by triggering adipose tissue lipolysis. Increased SNA emerges as a critical driver in the pathogenesis of overnutrition-induced insulin resistance and metabolic disease independent of cellular insulin signaling.

Self-Nanoemulsifying Formulation Improves Oral Bioavailability and Insulin Sensitizing Potency of Formononetin-Vitamin E Conjugate in Type 2 Diabetic Mice

The escalating incidence of obesity, diabetes, and insulin resistance has become a significant global health concern. In this study, we have developed a self-nanoemulsifying delivery system (SNEDS) of formononetin-vitamin E conjugate (VESylated-FMN) for improving its oral bioavailability and improving insulin sensitivity and glycemic control. The developed SNEDS were characterized using dynamic light scattering and transmission electron microscopy. Thereafter, the loading capacity, in vitro release, thermodynamic, and gastrointestinal stability of the developed formulation were evaluated. The safety and oral bioavailability of VESylated-FMN-SNEDS were assessed in Sprague-Dawley rats, whereas insulin-sensitizing potency was assessed in high-fat diet-induced type 2 diabetic mice. The VESylated-FMN-SNEDS quickly emulsified on dilution (droplet size ∼79.17 nm) and showed remarkable thermodynamic and gastrointestinal stability. The developed formulation demonstrated enhanced oral bioavailability (∼1.3-fold higher AUC0-t) of VESylated-FMN without liver and kidney injury. Consequently, VESylated-FMN-SNEDS significantly improves insulin sensitivity and glycemic control in HFD-fed mice compared to VESylated-FMN by upregulating the transcript level of insulin-sensitizing genes. Therefore, the SNEDS formulation could be an effective strategy to augment the oral bioavailability and insulin-sensitizing potency of VESylated-FMN.

Phenotypic screening in zebrafish larvae identifies promising cyanobacterial strains and pheophorbide a as insulin mimetics

Diabetes is a pandemic disease that causes the loss of control of glucose regulation in the organism, in consequence of dysfunction of insulin production or functionality. In this work, the antidiabetic bioactivity of 182 fractions from 19 cyanobacteria strains derived from the LEGE Culture Collection were analysed using the 2-NBDG assay in zebrafish larvae. From this initial screening, two fractions (57 (06104_D) and 107 (03283_B)) were identified as promising insulin mimetics. These were further characterized by measuring glucose levels in whole larvae, the expression of glucose transporters (GLUT 1-3) using western blot, and the mRNA expression levels of the glut2, pepck, and insa genes using real-time qPCR. Both fractions showed a decrease in free glucose levels. Furthermore, exposure to fraction 06104_D decreased GLUT1 and increased insa mRNA levels. The chemical composition of these fractions was determined using LC-HRESIMS/MS and compared to inactive fractions of the same polarity in order to identify the unique bioactive molecules. The molecular networks constructed using the GNPS platform revealed that fraction 06104_D contained mass clusters primarily composed of chlorins, lipids, and terpenoids, while fraction 03283_B contained xanthophylls, peptides, and terpenoids. To correlate the observed activity with the chemical composition of fraction 06104_D, pheophorbide a was chosen as a representative of chlorophyll derivatives. Exposure to zebrafish larvae at 10 and 20 µM confirmed the increased glucose uptake on the 2-NBDG assay. These findings highlight the bioactivity of chlorophyll derivatives as insulin mimetic compounds, as well as cyanobacteria as a source of potential therapeutic diabetes applications.

Fighting Fire with Fire: Impact of Sugary Diets on Metabolically Deranged Mice

Background/Objectives: There is controversy about the health risks of sugary diets. A recent study reported that chronic consumption of 11% sugar solutions improved glycemic control in lean mice. Based on this finding, we hypothesized that chronic consumption of the same 11% sugar solutions would also improve glycemic control in metabolically deranged mice. Methods: We exposed mice to a high-fat/high-sugar diet for 12 weeks. Then, we switched the mice to a control (i.e., standard chow) or one of four experimental diets for 8 weeks. The experimental diets contained standard chow plus an 11% solution of glucose or high-fructose syrup. The sugar syrups were derived from corn or cellulose. We included the cellulosic syrups because they contain polyphenols, which are thought to promote glycemic control. We measured body weight, adiposity, glucose tolerance, insulinemia, insulin sensitivity, body composition, and avidity for sweeteners. Results: Mice switched to the control diet lost weight, whereas mice switched to the experimental diets remained obese and hyperinsulinemic. Thus, the experimental diets did not cause the mice to regain normal metabolic health. Nevertheless, we observed (i) improvements in glucose tolerance in mice on both the control and experimental diets; (ii) reduced insulinemia and enhanced insulin sensitivity in mice offered the cellulosic syrups; (iii) elevations in cephalic-phase insulin responses in mice on the experimental diets; and (iv) increased avidity for sweeteners in mice on the control but not the experimental diets. Conclusions: Switching metabolically deranged mice to the experimental diets, particularly those with cellulosic sugars, improved glucose tolerance and insulin sensitivity.

Effect of Long-Term Taurine Supplementation on the Lipid and Glycaemic Profile in Adults with Overweight or Obesity: A Systematic Review and Meta-Analysis

BACKGROUND

Taurine has been demonstrated to regulate and improve metabolic health. However, physiological and pathological differences among individuals with overweight or obesity may result in varied responses to taurine supplementation. This study aims to estimate the effects of long-term taurine supplementation on blood lipids, glycemia, and insulin sensitivity in adults with overweight or obesity through a systematic review and meta-analysis.

METHODS

The literature search was based on six databases (Web of Science, PubMed, Scopus, EMBASE, Cochrane, and SPORTDiscus) up to October 2024. Subgroup analyses were performed based on daily taurine intake dosage (<3 g or 3 g), overweight (BMI 25-29.9 kg/m2), and obesity (BMI ≥30 kg/m2).

RESULTS

The final number of studies that met the inclusion criteria was 9 RCTs. The overall analysis showed that taurine supplementation significantly decreased TG (WMD = -0.56 mg/dL, 95% CI: -0.92 to -0.2, p = 0.002, I2 = 63%), TC (WMD = -0.71 mg/dL, 95% CI: -1.17 to -0.25, p = 0.002, I2 = 73%), and fasting insulin (WMD = -2.15 µU/mL, 95% CI: -3.24 to -1.06, p = 0.0001, I2 = 9%). In the subgroup analysis, long-term taurine intake led to BMI improvement in overweight adults (WMD = -1.14 kg/m2, 95% CI: -1.81 to -0.47, p = 0.0008, I2 = 0%). Meanwhile, improvements in HbA1c (WMD = -0.33%, 95% CI: -0.53 to -0.12, p = 0.002, I2 = 16%) and HOMA-IR (WMD = -0.91, 95% CI: -1.74 to -0.08, p = 0.003, I2 = 54%) were observed only in obese participants following taurine supplementation. Additionally, the long-term intake of 3 g of taurine significantly improved HbA1c (WMD = -0.37%, 95% CI: -0.61 to -0.13, p = 0.003, I2 = 0%) and FPG levels (WMD = -7.14 mg/dL, 95% CI: -12.53 to -1.74, p = 0.003, I2 = 70%) in overweight/obesity.

CONCLUSIONS

Long-term taurine supplementation is particularly effective in improving glycemic control and insulin sensitivity in obesity. Furthermore, higher doses of taurine (3 g per day) demonstrate even greater improvements in glycemic control.

1H NMR-Based Metabolomic Signatures in Rodent Models of Sporadic Alzheimer's Disease and Metabolic Disorders

Alzheimer's disease (AD) is a chronic neurological disorder that impacts the elderly population all over the globe. Evidence suggests association between AD and metabolic disorders such as diabetes mellitus (DM) and obesity (OB). The present study is an attempt to evaluate metabolic alterations in the serum and brain through NMR spectroscopy with the aim to identify shared metabolic signatures. AD was induced in rats by stereotactic intracerebroventricular injection of oligomerized Aβ-42 peptide into the brain. DM and OB were induced by intraperitoneal injection of streptozotocin and feeding rats on a high-fat diet, respectively. The metabolic alterations obtained through 1H NMR spectroscopy were further subjected to multivariate analysis by principal component analysis and partial least-squares discrimination for identification of metabolic signatures. In the serum, the levels of lactate and betaine were increased in AD, DM, and OB rats. On the other hand, the metabolite profile of brain indicated increase in the levels of lactate, N-acetylaspartate, and creatinine in AD, DM, and OB rats. Additionally, the concentration of neurochemicals such as glutamate, GABA, N-acetylglutamate, and myo-inositol were also elevated. The alterations in neurotransmitters and cerebral energy metabolism were accompanied by deficits in cognition assessed by Morris water maze in AD, DM, and OB rats. The perturbed metabolic profiles were accompanied by the presence of pathogenic amyloid deposits visualized by Congo red stain in the brains of AD, DM, and OB rats. Overall, the study identifies common metabolic signatures in AD, DM, and OB that may be involved in etiopathogenesis and also suggests linkages between these three conditions.

Light modulates glucose and lipid homeostasis via the sympathetic nervous system

Light is an important environmental factor for vision and for diverse physiological and psychological functions. Light can also modulate glucose metabolism. Here, we show that in mice, light is critical for glucose and lipid homeostasis by regulating the sympathetic nervous system, independent of circadian disruption. Light deprivation from birth elicits insulin hypersecretion, glucagon hyposecretion, lower gluconeogenesis, and reduced lipolysis by 6 to 8 weeks in male, but not female, mice. These metabolic defects are consistent with blunted sympathetic activity, and indeed, sympathetic responses to a cold stimulus are substantially attenuated in dark-reared mice. Further, long-term dark rearing leads to body weight gain, insulin resistance, and glucose intolerance. Notably, metabolic dysfunction can be partially alleviated by 5 weeks exposure to a regular light-dark cycle. These studies provide insight into circadian-independent mechanisms by which light directly influences whole-body physiology and better understanding of metabolic disorders linked to aberrant environmental light conditions.

High-fat diet mouse model receiving L-glucose supplementations propagates liver injury

Background and aims

Limited data link manufactured sweeteners impact on metabolic dysfunction-associated steatotic liver disease (MASLD). We aimed to evaluate the effects of manufactured sugars (L-glucose) compared to natural sugars (D-glucose) on phenotype, molecular and metabolic changes in mice models fed with either regular diet (RD) or high fat diet (HFD).

Methods

C57BL/6 mice fed 16-weeks with either RD; 70% carbohydrate or HFD; 60% fat, with or without additional glucose (Glu, at 18% w/v) to drinking tap water at weeks 8-16; of either natural (D-Glu) or manufactured (L-Glu) sugars. Liver inflammation (ALT and AST serum levels, liver H&E histologic stains and cell viability profile by p-AKT), liver fibrosis [quantitated α smooth-muscle-actin (αSMA) by western blot and RT-PCR, Masson Trichrome staining (MTC) of liver tissue], liver lipid [steatosis stain by H&E, Adipose Differentiation-Related Protein (ADRP) lipid accumulation, serum and lipid peroxidation Malondialdehyde (MDA) markers by ELISA], glucose hemostasis (serum Glucose and C-peptide with HOMA-IR score calculation) and liver aspects [hepatic glucose transporter 2 (GLUT2), insulin receptor (IR) expressions and GYS2/PYGL ratio] evaluated.

Results

D- and L-Glu supplementations propagate hepatocytes ballooning and steatosis in HFD-fed mice and were associated with αSMA down-expressions by 1.5-fold compared to the untreated group while showed an acceleration in liver fibrosis in the RD-fed mice. Lipid profile (Steatosis, ADRP and MDA) significantly increased in HFD-fed mice, both Glu supplementations (mainly the L-Glu) increased serum MDA while decreased ADRP. HOMA-IR score and IR significantly increased in HFD-fed mice, with further elevation in HOMA-IR score following Glu supplementations (mainly L-Glu). The increase in HOMA-IR negatively correlated with IR and Glut2 expressions. D- and L-Glu supplementations showed significant decrease of Glycogenesis (low GYS2/PYGL ratio) and unchanged p-AKT pattern compared to their RD counterparts.

Conclusion

Our data indicate an increase in rate of de-novo lipogenesis (DNL) in RD-fed mice (High carbohydrate diet) and liver fibrosis following additional sugar supplementations. In contrast, HFD-fed mice (with pre-existing high lipid profile) supplemented with sugar showed less liver fibrosis, because of reduced de-novo fatty acids synthesis and subsequently, the lipid oxidation pathways become dominated and induce the net results of lipid clearance.

Tools for regulating metabolic diseases: extracellular vesicles from adipose macrophages

Metabolic diseases have gradually become one of the most significant global medical burdens. Diseases such as obesity, diabetes, and metabolic syndrome, along with their complications, are clinically categorized as metabolic diseases. Long-term oral medication significantly reduces patient compliance and quality of life. Therefore, alternative therapies that intervene at the cellular level or target the root causes of metabolic diseases might help change this predicament. Research has found that extracellular vesicles derived from adipose macrophages can effectively regulate metabolic diseases by influencing the disease's development. This regulation is likely related to the role of these extracellular vesicles as important mediators in modulating adipose tissue function and insulin sensitivity, and their involvement in the crosstalk between adipocytes and macrophages. This review aims to describe the regulation of metabolic diseases mediated by adipose macrophage-derived extracellular vesicles, with a focus on their involvement in adipocyte crosstalk, the regulation of metabolism-related autoimmunity, and their potential as therapeutic agents for metabolic diseases, providing new avenues for diagnosis and treatment.

Deciphering the potential of Cymbopogon citratus (DC.) Stapf as an anti-obesity agent: phytochemical profiling, in vivo evaluations and molecular docking studies

Based on its anti-inflammatory and antioxidant properties, Cymbopogon citratus (DC) Stapf is commonly used in traditional and modern medicine to cure different diseases. The present study investigates the potential of C. citratus organic extract as an anti-obesity drug in a HCHFD (high-carbohydrate, high-fat diet) model for obese rats. Its negative hypolipidemic effect has been confirmed through biochemical and histological methods. Fifty male albino rats were randomly divided into five groups (10 rats each) Group I (Control group), Group II (HCHFD group), Group III (C. citratus group), Group IV (HCHFD + C. citratus group) and Group V (HCHFD + Orlistat group). Serum glucose levels and lipid profiles were quantified using a spectrophotometer. Insulin, apelin, and adiponectin parameters were measured using ELISA (enzyme-linked immunosorbent assay) kits, while real-time PCR following extraction and purification was used for apelin, apelin receptor genes (APJ), and adiponectin gene expression evaluation. Besides, C. citratus methanolic extract was subjected to untargeted metabolic profiling via RP-HPLC-QTOF-MS and MS/MS, disclosing the presence of 52 secondary metabolites where they mainly belonged to phenolic compounds viz., flavones and hydroxycinnamic acids, among other metabolites with predominance of derivatives of luteolin and O-coumaroyl-O-feruloylglycerol. Our findings were further strengthened by computational-based virtual screening protocols that included molecular docking (MDock) and Structure-Activity Relationships (SARs). The MDock studies revealed that the three main flavone-containing metabolites, each with a luteolin C6-glycosylation core featuring two sugar units (16, 25, and 31), outperformed the positive control (8EH, a triazole derivative) known to bind to the APJ protein. These metabolites exhibited exceptional binding affinities, with estimated free binding energy (ΔGB) values of -9 kcal mol-1 or lower, likely due to potential hydrogen bond interactions with the Arg168 residue of the APJ protein. Additionally, the pharmacokinetic, physicochemical, and toxicity profiles of the 11 major metabolites from C. citratus leaf extract were assessed, revealing a profile like that of the positive control in the three selected flavone metabolites. Based on the acquired data, it can be concluded that C. citratus shows strong potential as a hypolipidemic agent and could play a significant role in managing obesity and mitigating its associated complications.

Mitigation of Atherosclerotic Vascular Damage and Cognitive Improvement Through Mesenchymal Stem Cells in an Alzheimer's Disease Mouse Model

Alzheimer's disease (AD) is a neurodegenerative condition characterized by progressive memory loss and other cognitive disturbances. Patients with AD can be vulnerable to vascular damage, and damaged vessels can lead to cognitive impairment. Mesenchymal stem cell (MSC) treatment has shown potential in ameliorating AD pathogenesis, but its effect on vascular function remains unclear. This study aimed to improve cognitive function by alleviating atherosclerosis-induced vessel damage using MSCs in mice with a genetic AD background. In this study, a 5xFAD mouse model of AD was used, and atherosclerotic vessel damage was induced by high-fat diets (HFDs). MSCs were injected into the tail vein along with mannitol in 5xFAD mice on an HFD. MSCs were detected in the brain, and vascular damage was improved following MSC treatment. Behavioral tests showed that MSCs enhanced cognitive function, as measured by the Y-maze and passive avoidance tests. Additionally, muscle strength measured by the rotarod test was also increased by MSCs in AD mice with vessel damage induced by HFDs. Overall, our results suggest that stem cells can alleviate vascular damage caused by metabolic diseases, including HFDs, and vascular disease in individuals carrying the AD gene. Consequently, this alleviates cognitive decline related to vascular dementia symptoms.

Association Between Serum Concentrations of (Certain) Metals and Type 2 Diabetes Mellitus

The findings regarding trace element concentrations in patients diagnosed with type 2 diabetes and healthy controls are inconsistent, and therefore, we determined to gather them in the form of a review to further indicate the need for more advanced knowledge development. In our study, we reviewed articles and studies that involved the topics of micronutrient and metal associations with the occurrence and development of type 2 diabetes. We mainly included works regarding human-based studies, but with limited research results, animal-based research was also taken into account. With some newer studies, we reached for initial assumptions of previous statements. The results indicated that higher serum levels of lead, cadmium, arsenic, bromine, barium, strontium, nickel, aluminum, calcium, copper, and ferritin are positively associated with diabetic prevalence. Both too-low and too-high levels of zinc, selenium, and magnesium may be connected to the development of diabetes. Chromium has the capability of insulin response modulation, with enhanced insulin-cell binding, and thus, lower serum levels of chromium can be found in diabetic patients. There are contradictory discoveries regarding manganese. Its supplementation can possibly cease the development of insulin resistance and type 2 diabetes. On the contrary, other studies reported that there is no such connection. Our work indicates that, as micronutrients play a significant role in the pathogenesis of metabolic disorders, more research regarding their bodily homeostasis and type 2 diabetes should be conducted.

Association analysis between serum asprosin and metabolic characteristics, Complications in type 2 diabetic patients with different durations

AIMS/INTRODUCTION

To investigated the association between serum asprosin and metabolic characteristics in type 2 diabetes mellitus patients with different durations.

MATERIALS AND METHODS

A total of 436 patients with type 2 diabetes mellitus were enrolled in this study from the community health service center in southeastern Shanxi Province. All the patients were divided into two groups according to their diabetes duration: diabetes duration ≤5 years group (n = 132) and diabetes duration ≥10 years group (n = 304). Fasting blood samples were gathered and serum asprosin was tested. Pearson/Spearman correlation analysis was carried out.

RESULTS

Asprosin was comparable between the two groups. Asprosin was positively correlated with systolic blood pressure (SBP), triglycerides, creatinine, serum uric acid and low-density lipoprotein cholesterol in the diabetes duration ≤5 years group (P < 0.05). In the diabetes duration ≥10 years group, asprosin was independently correlated with SBP, diastolic blood pressure, body mass index, total cholesterol, triglycerides, low-density lipoprotein cholesterol, creatinine, serum uric acid, fasting plasma glucose and glycosylated hemoglobin (P < 0.05). Asprosin was associated with alanine aminotransferase and estimated glomerular filtration rate (P < 0.05). Multiple linear regression analysis found that SBP and diastolic blood pressure is an independent factor related to serum asprosin in the group with diabetes duration ≤5 years (P < 0.05). Fasting plasma glucose, SBP, total cholesterol and serum uric acid is an independent factor related to serum asprosin in the group with diabetes duration ≥10 years (P < 0.05).

CONCLUSIONS

Serum asprosin was significantly increased in the group with diabetes duration ≥10 years, and glycosylated hemoglobin, blood pressure and estimated glomerular filtration rate were independent risk factors in long-duration type 2 diabetes mellitus.

Polyphenols from Prunus salicina L. alleviate weight gain, obesity-related hyperlipidemia, hepatic steatosis, hyperglycemia, and modulate gut microbiota in mice fed a high-fat diet

Hyperlipidemia, hepatic steatosis, and hyperglycemia are prevalent metabolic disorders closely linked to obesity. The objective of this research was to examine the potential advantageous impacts of polyphenols extracted from Prunus salicina L. fruit (PSFP) on hyperlipidemia, hepatic steatosis, and hyperglycemia induced by a high-fat diet (HFD), as well as to elucidate the underlying mechanisms involved. Male C57BL/6J mice, free from specific pathogens, were assigned randomly into three groups. These groups were then subjected to a 14-week dietary intervention, including a low-fat diet, an HFD, or an HFD plus with PSFP via intragastric administration. The obesity-related biochemical indexes were evaluated. To assess alterations in gut microbiota resulting from PSFP treatment, 16S rRNA sequencing was performed. UPLC-ESI-MS/MS assay identified 162 distinct polyphenolic compounds in PSFP. The administration of PSFP significantly reduced both body weight gain and hyperlipidemia induced by HFD. In addition, PSFP ameliorated hepatic steatosis induced by HFD and enhanced liver function in mice. PSFP treatment also ameliorated HFD-induced insulin resistance and hyperglycemia, evidenced by the observed decrease in fasting serum concentrations of glucose and insulin, improved insulin sensitivity, and restored glucose tolerance. Moreover, PSFP modulated the composition and abundance of specific microbial genus, including Lachnospiraceae NK4A136 group, Akkermansia, Parabacteroides, Enterococcus, Adlercreutzia, and Roseburia. Correlation analysis indicated significant associations between gut microbiota and physiological indices associated with obesity. These findings suggested that PSFP supplementation ameliorated HFD-induced hyperlipidemia, hepatic steatosis, and hyperglycemia, potentially through modulating the gut microbiota composition and abundance of specific taxa.

Chicken GLUT4 function via enhancing mitochondrial oxidative phosphorylation and inhibiting ribosome pathway in skeletal muscle satellite cells

Glucose Transporter 4 (GLUT4) is a crucial protein facilitating glucose uptake and metabolism across cell membranes in mammals. However, information on GLUT4 in birds has historically been limited. In this study, we investigated the dynamic expression profile of chicken GLUT4 using real-time quantitative PCR (RT-qPCR) and examined its potential effects and mechanisms via GLUT4 overexpression and RNA sequencing (RNA-seq) in chicken primary skeletal muscle satellite cells (CP-SMSCs). Our results demonstrated that chicken GLUT4 is differentially expressed across tissues, with predominant expression in skeletal muscles, and across developmental stages of CP-SMSCs, with notable upregulation during the phases of cell proliferation and early differentiation. Notably, 0.1 μM insulin for 60 min significantly elevated the expression of GLUT4 in CP-SMSCs (P < 0.05). GLUT4 overexpression in CP-SMSCs promoted cell proliferation, as evidenced by Cell Counting Kit-8 (CCK-8) (P < 0.05) and 5-Ethynyl-2'-Deoxyuridine (EDU) assays (P < 0.05), and enhanced glucose consumption following 0.1 μM insulin treatment (P < 0.05). However, it inhibited glucose consumption 12 h after the addition of 5 g/L glucose (P < 0.05). After overexpressing GLUT4, we identified 302 differentially expressed genes (DEGs) in CP-SMSCs, with 134 upregulated and 168 downregulated. These DEGs are primarily enriched in pathways such as oxidative phosphorylation, ribosome, cardiac muscle contraction, ATP metabolic processes, and mitochondrial protein complexes. Specifically, in the enriched oxidative phosphorylation pathway, the upregulated DEGs (12) encode mitochondrial proteins, while the downregulated DEGs (6) are nuclear genome-derived. The ribosomal pathway is predominantly inhibited, accompanying with the downregulation of the translocase of outer mitochondrial membrane 7 (TOMM7)/translocase of inner mitochondrial membrane 8 (TIMM8A) complex responsible for mitochondrial protein transport, and a reduction in 28S (LOC121106978) and 18S (LOC112533601) ribosomal rRNAs. In conclusion, chicken GLUT4 is dynamically modulated during development and acts as an insulin responder that significantly regulates cellular glucose uptake and cell proliferation. This regulation occurs mainly through enhancing the mitochondrial oxidative phosphorylation and inhibiting ribosomal pathway.

Lignan-rich extract from Cinnamomum camphora leaf attenuates metabolic syndrome by modulating glycolipid metabolism and gut microbiota in T2DM mice

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a serious metabolic syndrome with high mortality and disability rates globally, which usually caused by unhealthy dietary patterns. Cinnamomum camphora leaf is a traditional Chinese medicinal herb used for attenuating hyperglycemia and digestive disorder, and high level of lignans has been found in C. camphora leaf.

PURPOSE

This study aimed to examine the chemical composition of lignans extracted from C. camphora leaf (LCCL), and illustrate its therapeutic effect and mechanism on T2DM and its concomitant glycolipid metabolic disorder.

METHODS

The components of LCCL were separated and purified by silica gel and macroporous adsorption resin, and were distinguished through LC/MS and NMR. The antioxidant activity of LCCL was determined by free radical scavenging assay in vitro; the hypoglycemic and hypolipidemic abilities were evaluated by α-glucosidase, α-amylase and pancreatic lipase inhibition trials, respectively. T2DM model mice were established by high-sugar and high-fat (HSHF) feed together with streptozotocin (STZ) infection, and then grouped to assess the effect of LCCL treatment. Hematoxylin-eosin (H&E), Periodic Acid-Schiff (PAS) and oil red O staining were employed to analyze the histopathology. qRT-PCR assay, 16S rRNA analysis, and western blot were conducted to illuminate the anti-diabetic mechanism of LCCL.

RESULTS

6 sesamin lignans were identifed from LCCL. The in vitro assays showed strong inhibitive abilities of LCCL with low IC50 on DPPH (33.68 ± 0.54 μg/ml),O2- (39.25 ± 0.61 μg/ml), OH• (45.72 ± 0.72 μg/ml), α-glucosidase (0.82 ± 0.14 mg/ml), α-amylase (0.86 ± 0.11 mg/ml) and pancreatic lipase (0.91 ± 0.12 mg/ml). LCCL treatment (100, 200 and 400 g kg-1mg kg-1) gradually decreased the fasting blood glucose (FBG) and fasting insulin (FINS), improved the glucose and insulin tolerance, down-regulated the homeostasis model assessment insulin resistance (HOMA-IR) indexes, alleviated the hepatic inflammatory response and oxidative stress, promoted the glycogen storage and depleted the fat accumulation in the liver. Besides, LCCL administration alleviated the glycolipid metabolism disorder in T2DM mice with a gut microbiota dependent manner, that significantly increased biodiversity, altered the composition of gut microbiota and increased the proportion of Lactobacillus.

CONCLUSION

The lignan-rich extract of C. camphor leaf (LCCL), containing at least 6 lignans compounds, displayed promising antioxidant, hypoglycemic and hypolipidemic activities. The treatment of LCCL alleviated the glycolipid metabolism disorder in T2DM mice with a gut microbiota dependent manner. These finding suggested that LCCL should be further investigated to develop its complementary therapeutic effect on T2DM.

The triggering pathway, the metabolic amplifying pathway, and cellular transduction in regulation of glucose-dependent biphasic insulin secretion

INTRODUCTION

Insulin secretion is a highly regulated process critical for maintaining glucose homeostasis. This abstract explores the intricate interplay between three essential pathways: The Triggering Pathway, The Metabolic Amplifying Pathway, and Cellular Transduction, in orchestrating glucose-dependent biphasic insulin secretion.

MECHANISM

During the triggering pathway, glucose metabolism in pancreatic beta-cells leads to ATP production, closing ATP-sensitive potassium channels and initiating insulin exocytosis. The metabolic amplifying pathway enhances insulin secretion via key metabolites like NADH and glutamate, enhancing calcium influx and insulin granule exocytosis. Additionally, the cellular transduction pathway involves G-protein coupled receptors and cyclic AMP, modulating insulin secretion.

RESULT AND CONCLUSION

These interconnected pathways ensure a dynamic insulin response to fluctuating glucose levels, with the initial rapid phase and the subsequent sustained phase. Understanding these pathways' complexities provides crucial insights into insulin dysregulation in diabetes and highlights potential therapeutic targets to restore glucose-dependent insulin secretion.

Exploring the key role of DNA methylation as an epigenetic modulator in oxidative stress related islet cell injury in patients with type 2 diabetes mellitus: a review

Type 2 diabetes mellitus (T2DM) is a multifactorial metabolic disorder characterised by impaired insulin secretion and action, often exacerbated by oxidative stress. Recent research has highlighted the intricate involvement of epigenetic mechanisms, particularly DNA methylation, in the pathogenesis of T2DM. This review aims to elucidate the role of DNA methylation as an epigenetic modifier in oxidative stress-mediated beta cell dysfunction, a key component of T2DM pathophysiology. Oxidative stress, arising from an imbalance between reactive oxygen species (ROS) production and antioxidant defence mechanisms, is a hallmark feature of T2DM. Beta cells, responsible for insulin secretion, are particularly vulnerable to oxidative damage due to their low antioxidant capacity. Emerging evidence suggests that oxidative stress can induce aberrant DNA methylation patterns in beta cells, leading to altered gene expression profiles associated with insulin secretion and cell survival. Furthermore, studies have identified specific genes involved in beta cell function and survival that undergo DNA methylation changes in response to oxidative stress in T2DM. These epigenetic modifications can perpetuate beta cell dysfunction by dysregulating key pathways essential for insulin secretion, such as the insulin signalling cascade and mitochondrial function. Understanding the interplay between DNA methylation, oxidative stress, and beta cell dysfunction holds promise for developing novel therapeutic strategies for T2DM. Targeting aberrant DNA methylation patterns may offer new avenues for restoring beta cell function and improving glycemic control in patients with T2DM. However, further research is needed to elucidate the complex mechanisms underlying epigenetic regulation in T2DM and to translate these findings into clinical interventions.

Insulin Resistance in Hypercalciuric Calcium Kidney Stone Patients

Rational & Objective

Diabetes and uric acid kidney stones are strongly associated. Patients with calcium kidney stones also have higher risk of developing diabetes compared with nonkidney stone patients yet this has not been further investigated. We aimed to characterize insulin resistance in calcium kidney stone patients.

Study Design

Observational.

Setting & Population

This study was performed in the University of Chicago Clinical Research Center. Kidney stone patients (N = 42) were selected for having idiopathic hypercalciuria and calcium stones with no other medical conditions, and controls (N = 27) were healthy.

Exposures

All participants presented to the Clinical Research Center in a fasting state and at least 2 timed fasting blood and urine collections were collected before a fixed breakfast. Six additional timed blood and urine collections were performed after breakfast.

Outcomes

We compared fasting and fed indices of insulin resistance between the groups.

Analytic Approach

We used t tests and multivariable linear regression models. A sensitivity analysis removing all patients who had ever been on a thiazide diuretic was also performed.

Results

In separate multivariable linear models, kidney stone patients had higher fasting serum insulin levels (24 (3-46 pmol/L), P = 0.03) and higher homeostatic model of insulin resistance (HOMA-IR) (1.0 (0.2-1.8), P = 0.02). In separate multivariable linear models, kidney stone patients had higher fed serum glucose levels (10 (2-18 mg/dL), P = 0.01). Results were similar in a sensitivity analysis removing all patients who had ever been on a thiazide diuretic. There were no differences in urine composition based on HOMA-IR levels.

Limitations

Single institution. Small sample size limited subanalyses by different calcium stone types.

Conclusions

Calcium kidney stone patients without diabetes or other medical conditions demonstrated signs of insulin resistance compared with healthy matched controls.

Gut Microbiota-microRNA Interactions and Obesity Pathophysiology: A Systematic Review of Integrated Studies

Obesity is the fifth leading cause of death globally and its comorbidities put a high burden on societies and cause disability. In this review, we aim to summarize the interactions and crosstalk between gut microbiota and micro-RNA (miRNA) in obesity. We searched for the relevant literature through PubMed, Web of Science, Scopus, and Science Direct. The study design is registered in the international prospective register of systematic reviews (Prospero). According to the inclusion criteria, eight studies were eligible for assessment (two studies including human subjects and six studies including animal subjects). We report that the interactions of miRNA and gut microbiota in the context of obesity are diverse and in some cases tissue specific. However, the interactions mediate obesity-associated pathways including the inflammatory response, oxidative stress, insulin signaling, gut permeability, and lipogenesis. To mention the most meaningful results, the expression of adipose tissue miRNA-378a-3p/5p was associated with Bifidobacterium and Akkermansia abundance, the expression of hepatic miRNA-34a was related to the Firmicutes phylum, and the expression of miRNA-122-5p and miRNA-375 was associated with the Bacteroides genus. miRNA-microbiota-associated pathological pathways seem to provide an intricate, but promising field for future research directed toward the treatment of obesity and its comorbidities.

Pilot Data Suggest That Obesity and Presence of Malignancy Are Associated with Altered Immune Cell Infiltration in Endometrial Biopsies

(1) Background: The worldwide endometrial cancer (EC) incidence is rising, amongst others linked to obesity, type 2 diabetes mellitus (T2DM), and metabolic syndrome, possibly due to low-grade adipose tissue inflammation. We studied immune cell infiltration in the endometrium in relation to diagnosis and obesity. (2) Methods: A cohort was created (n = 44) from postmenopausal women, lean (n = 15) and obese (n = 29), with bleeding complaints due to EC (n = 18) or benign pathology (n = 26). Endometrial biopsies were used to study the immune microenvironment and stained for macrophages (CD68 and CD163), T-cells (CD3 and CD8), and NK-cells (CD56). (3) Results: Malignant samples showed reduced intraepithelial CD3+ and CD8+ T-cells and increased stromal CD3+ T-cells. In obese patients, increased intraepithelial CD3+ and CD8+ T-cells were detected, especially in obese patients with T2DM. Epithelial CD56+ NK-cells were depleted in EC; however, no effect of obesity on NK-cell infiltration was observed. Stromal CD68+ cells were reduced in EC patients, whereas the CD163+ cells were increased. (4) Conclusions: Obesity and malignancy are associated with differences in immune cell presence. The alterations in immune cell infiltration seen in obese EC patients with and without diabetes suggest a complex interaction where obesity-related low-grade inflammation plays a central role.

Aerobic exercise attenuates insulin resistance via restoring branched chain amino acids homeostasis in obese mice

Introduction

Emerging evidences suggests that the disrupted branched-chain amino acids (BCAAs) homeostasis and elevated BCAAs promote obesity-related insulin resistance (IR). Exercise improves insulin sensitivity. However, whether BCAAs plays a role in the exercise-attenuated IR remains to be fully investigated.

Methods

In this study, male C57BL/6J mice were induced to become diet-induced obese (DIO) and served as subjects. The initial investigation focused on the impact of exercise on IR and BCAAs. The DIO mice were randomly assigned to either a sedentary group (CON, n = 16) or an exercise group (EX, n = 16). The EX group underwent a 12-week aerobic exercise regimen on a treadmill. After 12-week, plasma BCAAs and branched-chain keto acids (BCKAs) were measured by liquid chromatography-mass spectrometry, glucose tolerance test (GTT) and insulin tolerance test (ITT) were performed, and the expression and phosphorylation of BCAAs catabolic proteins, as well as AKT T308 in gastrocnemius muscle and liver tissues, were evaluated using western blotting. Subsequently, the study explored the role of BCAAs in enhancing IR through exercise. Mice were randomly allocated into 4 groups: sedentary group (CON, n = 8), sedentary with BCAAs supplementation group (CON+BCAA, n = 8), exercise group (EX, n = 16), and exercise with BCAAs supplementation group (EX+BCAA, n = 16). The exercise protocol was as above. Mice in the BCAAs supplemented groups received drinking water containing 2% BCAAs. After 12-week, plasma BCAAs and BCKAs were measured, GTT and ITT tests were performed, and the phosphorylation of AKT T308, as well as p70S6K T389 in gastrocnemius muscle and liver, were compared between the EX group and the EX+BCAA group. Additionally, the phosphorylation of AMPKα T172 in both tissues was measured across all four groups.

Results

12-week aerobic exercise improved insulin sensitivity in DIO mice while inducing BCAAs catabolic protein expression in skeletal muscle and liver, and reducing the plasma BCAAs level. Importantly, BCAAs supplementation elevated the plasma level of BCAAs and counteracted the exercise-attenuated IR. In skeletal muscle and liver tissues, BCAAs supplementation impaired the exercise-improved insulin signaling without enhancing mammalian target of rapamycin activity. AMPK activity was enhanced by aerobic exercise, which was abolished by BCAAs supplementation.

Conclusion

Aerobic exercise attenuated insulin resistance via restoring BCAAs homeostasis and AMPK activity. The impacts of BCAAs intake on the metabolic effects of exercise sheds light on the combined exercise and nutrition intervention strategy for diabetes management.

The P300-ARRDC3 axis participates in maternal subclinical hypothyroidism and is involved in abnormal hepatic insulin sensitivity in adult offspring

Numerous studies have suggested potential associations between maternal subclinical hypothyroidism (SCH) and adverse metabolic outcomes in offspring, however, the underlying mechanism remains unclear. In this study, we generated a maternal SCH mouse model by administering 50 ppm 6-propyl-2-thiouracil (PTU) in the drinking water of pregnant mice until delivery. This model was used to investigate the mechanisms influencing glucose metabolism in offspring. RNA sequencing (RNA-seq) revealed a substantial increase in ARRDC3 expression in the livers of the offspring of the SCH model mice, which may contribute to insulin resistance. Additionally, the phosphorylation levels of key proteins in the insulin signalling pathway, such as protein kinase B (Akt), glycogen synthase kinase 3 beta (GSK-3β), and Forkhead box protein O1 (FoxO1), were correspondingly reduced in the SCH offspring. Moreover, overexpression of ARRDC3 in Hepa1‒6 cells suppressed the Akt/GSK-3β/FoxO1 signalling pathway and increased the expression of glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK), which was consistent with the molecular changes observed in SCH offspring. Our results also indicated that the upregulation of ARRDC3 in SCH offspring may result from increased H3K27 acetylation of the ARRDC3 promoter region, driven by elevated expression of P300. Importantly, adequate L-T4 supplementation during pregnancy improved insulin sensitivity and reversed the molecular alterations in the insulin signalling pathway observed in SCH offspring. In conclusion, exposure to intrauterine SCH resulted in altering the P300-ARRDC3 axis in offspring and impaired insulin sensitivity by disrupting the Akt/GSK-3β/FoxO1 signalling pathway. Timely L-T4 supplementation during pregnancy is an effective strategy to prevent insulin resistance in offspring of SCH mothers. This study elucidates potential molecular mechanisms behind insulin resistance in SCH offspring and suggests novel therapeutic targets for treating metabolic disorders related to maternal SCH.

Assessing the validity of METS-IR for predicting the future onset of diabetes: an analysis using time-dependent receiver operating characteristics

BACKGROUND

The Metabolic Insulin Resistance Score (METS-IR) is a non-invasive proxy for insulin resistance (IR) that has been newly developed in recent years and has been shown to be associated with diabetes risk. Our aim was to assess the predictive value of METS-IR for the future development of diabetes and its temporal differences in people of different sex, age, and body mass index (BMI).

METHODS

The current study included 15,453 baseline non-diabetic subjects in the NAGALA cohort and then grouped according to the World Health Organization's (WHO) recommended criteria for age and BMI. Multivariate Cox regression and time-dependent receiver operator characteristics (ROC) curves were used to analyze the value of METS-IR in assessing and predicting the risk of diabetes in people of different sexes, ages, and BMIs.

RESULTS

373 individuals developed diabetes during the observation period. By multivariate COX regression analysis, the development of future diabetes was significantly associated with increased METS-IR, and this positive association was stronger in women than in men and in individuals < 45 years than in individuals ≥ 45 years; while no significant differences were observed between non-obese and overweight/obesity individuals. Using time-dependent ROC analysis we also assessed the predictive value of METS-IR for future diabetes at a total of 11-time points between 2 and 12 years. The results showed that METS-IR had a higher predictive value for the future development of diabetes in women or individuals < 45 years of age compared to men or individuals ≥ 45 years of age for almost the entire follow-up period. Furthermore, across different BMI categories, we also found that in the short term (3-5 years), METS-IR had a higher predictive value for the development of diabetes in individuals with overweight/obesity, while in the medium to long term (6-12 years), METS-IR was more accurate in predicting the development of diabetes in non-obese individuals.

CONCLUSIONS

Our study showed that METS-IR was independently associated with the development of future diabetes in a non-diabetic population. METS-IR was a good predictor of diabetes, especially for women and individuals < 45 years old for predicting the future risk of developing diabetes at all times.

Hepatokines: unveiling the molecular and cellular mechanisms connecting hepatic tissue to insulin resistance and inflammation

Insulin resistance arising from Non-Alcoholic Fatty Liver Disease (NAFLD) stands as a prevalent global ailment, a manifestation within societies stemming from individuals' suboptimal dietary habits and lifestyles. This form of insulin resistance emerges as a pivotal factor in the development of type 2 diabetes mellitus (T2DM). Emerging evidence underscores the significant role of hepatokines, as hepatic-secreted hormone-like entities, in the genesis of insulin resistance and eventual onset of type 2 diabetes. Hepatokines exert influence over extrahepatic metabolism regulation. Their principal functions encompass impacting adipocytes, pancreatic cells, muscles, and the brain, thereby playing a crucial role in shaping body metabolism through signaling to target tissues. This review explores the most important hepatokines, each with distinct influences. Our review shows that Fetuin-A promotes lipid-induced insulin resistance by acting as an endogenous ligand for Toll-like receptor 4 (TLR-4). FGF21 reduces inflammation in diabetes by blocking the nuclear translocation of nuclear factor-κB (NF-κB) in adipocytes and adipose tissue, while also improving glucose metabolism. ANGPTL6 enhances AMPK and insulin signaling in muscle, and suppresses gluconeogenesis. Follistatin can influence insulin resistance and inflammation by interacting with members of the TGF-β family. Adropin show a positive correlation with phosphoenolpyruvate carboxykinase 1 (PCK1), a key regulator of gluconeogenesis. This article delves into hepatokines' impact on NAFLD, inflammation, and T2DM, with a specific focus on insulin resistance. The aim is to comprehend the influence of these recently identified hormones on disease development and their underlying physiological and pathological mechanisms.

High-Intensity Interval Training, Caloric Restriction, or Their Combination Have Beneficial Effects on Metabolically Acquired Peripheral Neuropathy

Peripheral neuropathy (PN) is a prevalent and debilitating complication of obesity, prediabetes, and type 2 diabetes, which remains poorly understood and lacks disease-modifying therapies. Fortunately, diet and/or exercise have emerged as effective treatment strategies for PN. Here, we examined the impact of caloric restriction (CR) and high-intensity interval training (HIIT) interventions, alone or combined (HIIT-CR), on metabolic and PN outcomes in high-fat diet (HFD) mice. HFD feeding alone resulted in obesity, impaired glucose tolerance, and PN. Peripheral nerves isolated from these mice also developed insulin resistance (IR). CR and HIIT-CR, but not HIIT alone, improved HFD-induced metabolic dysfunction. However, all interventions improved PN to similar extents. When examining the underlying neuroprotective mechanisms in whole nerves, we found that CR and HIIT-CR activate the fuel-sensing enzyme AMPK. We then performed complimentary in vitro work in Schwann cells, the glia of peripheral nerves. Treating primary Schwann cells with the saturated fatty acid palmitate to mimic prediabetic conditions caused IR, which was reversed by the AMPK activator, AICAR. Together, these results enhance our understanding of PN pathogenesis, the differential mechanisms by which diet and exercise may improve PN, and Schwann cell-specific contributions to nerve insulin signaling and PN progression.

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