Glucose transporters: cellular links to hyperglycemia in insulin resistance and diabetes

Bioflavonoid combination attenuates diabetes-induced nephropathy in rats via modulation of MMP-9/TIMP-1, TGF-β, and GLUT-4-associated pathways

Background

Diabetic nephropathy represents a significant microvascular complication of diabetes, characterized by extracellular matrix accumulation, loss of cell-cell junctions, microalbuminuria, and diminished creatinine clearance. Despite its prevalence, therapeutic options dedicated to this condition are currently lacking. Natural products like bioflavonoids have garnered attention for their potential therapeutic benefits. The present study aimed to evaluate the efficacy of a bioflavonoid combination, including ginger extract, soy extract, and hesperetin, in a diabetic rat model.

Methods

Diabetes was initiated in the rat pups via intraperitoneal injection of streptozotocin on the fifth postnatal day. After six weeks, rats exhibiting blood sugar levels exceeding 160 mg/dL were allocated into diabetic control and treatment groups, with eight animals each. A subset of rats received citrate buffer as a control. The treatment group received the bioflavonoid combination orally for twenty-four weeks. Various parameters, including glycemic levels, urinary parameters, antioxidant status, mRNA expression via Western blot, gel zymography, and immunohistochemistry, were assessed at the study's conclusion.

Results

The bioflavonoid combination demonstrated significant reductions in hyperglycemia and various urinary parameters compared to controls. Notably, it modulated MMP-9/TIMP-1 expression, upregulated GLUT-4, and downregulated TGF-β. Additionally, the combination enhanced total antioxidant capacity, indicating potential antioxidative benefits.

Conclusions

This study highlights the therapeutic potential of a bioflavonoid combination (ginger extract, soy extract, and hesperetin) in improving renal function in diabetic nephropathy. By modulating key factors such as MMP-9/TIMP-1, TGF-β, and GLUT-4, this combination presents a promising avenue for further exploration in managing diabetic nephropathy. These findings underscore the importance of natural products as potential therapeutic agents in addressing diabetic complications.

The regulatory roles and clinical significance of glycolysis in tumor

Metabolic reprogramming has been demonstrated to have a significant impact on the biological behaviors of tumor cells, among which glycolysis is an important form. Recent research has revealed that the heightened glycolysis levels, the abnormal expression of glycolytic enzymes, and the accumulation of glycolytic products could regulate the growth, proliferation, invasion, and metastasis of tumor cells and provide a favorable microenvironment for tumor development and progression. Based on the distinctive glycolytic characteristics of tumor cells, novel imaging tests have been developed to evaluate tumor proliferation and metastasis. In addition, glycolytic enzymes have been found to serve as promising biomarkers in tumor, which could provide assistance in the early diagnosis and prognostic assessment of tumor patients. Numerous glycolytic enzymes have been identified as potential therapeutic targets for tumor treatment, and various small molecule inhibitors targeting glycolytic enzymes have been developed to inhibit tumor development and some of them are already applied in the clinic. In this review, we systematically summarized recent advances of the regulatory roles of glycolysis in tumor progression and highlighted the potential clinical significance of glycolytic enzymes and products as novel biomarkers and therapeutic targets in tumor treatment.

Triglyceride Glucose Index and Prognosis of Patients with Subarachnoid Hemorrhage

OBJECTIVE

The triglyceride glucose (TyG) index is regarded as a reliable alternative indicator for measuring insulin resistance. We investigated the association between the prognosis of patients with subarachnoid hemorrhage (SAH)and the TyG index, explored the potential of the TyG index as a new biomarker for forecasting the outcomes of SAH patients, and explored independent risk factors for predicting the condition of SAH patients.

METHODS

A retrospective analysis was performed of patients who were admitted to a single center due to SAH. Differences in clinical data and correlation between laboratory indexes, disease severity score on admission, and prognosis score were compared between the 2 groups. The study employed multivariate logistic regression analysis to examine the independent influencing aspects of Glasgow Outcome Scale score. The receiver operating characteristic curve was drawn and the area under the curve (AUC) calculated to predict the best cutoff value of the degree of neurological impairment in patients with SAH.

RESULTS

Univariate analysis showed that Glasgow Coma Scale score (86.3% vs. 12.0%, P < 0.001), Hunt-Hess grade (88.2% vs. 15.7%, P < 0.001), white blood cell count (11.20 [7.9, 15.2] vs. 9.1 [7.0, 12.2], P = 0.027), and TyG index (1.49 [1.40, 1.59] vs. 1.16 [1.06, 1.27], P < 0.001) were statistically significantly different. Multivariate analysis showed that TyG index, Hunt-Hess grade, and GCS score were independent risk factors for poor prognosis.

CONCLUSIONS

Patients with SAH may benefit from using the TyG index as a predictive method. In our clinical practice, the TyG index is beneficial for managing diseases and making decisions. More research is required to determine if improved TyG index control would lead to better clinical results in the future.

Madhuca longifolia-hydro-ethanolic-fraction reverses mitochondrial dysfunction and modulates selective GLUT expression in diabetic mice fed with high fat diet

BACKGROUND

Metabolic disorder is characterized as chronic low-grade inflammation which elevates the systemic inflammatory markers. The proposed hypothesis behind this includes occurrence of hypoxia due to intake of high fat diet leading to oxidative stress and mitochondrial dysfunction.

AIM

In the present work our aim was to elucidate the possible mechanism of action of hydroethanolic fraction of M. longifolia leaves against the metabolic disorder.

METHOD AND RESULTS

In the present investigation, effect of Madhuca longifolia hydroethanolic fraction (MLHEF) on HFD induced obesity and diabetes through mitochondrial action and selective GLUT expression has been studied. In present work, it was observed that HFD (50% of diet) on chronic administration aggravates the metabolic problems by causing reduced imbalanced oxidative stress, ATP production, and altered selective GLUT protein expression. Long term HFD administration reduced (p < 0.001) the SOD, CAT level significantly along with elevated liver function marker AST and ALT. MLHEF administration diminishes this oxidative stress. HFD administration also causes decreased ATP/ADP ratio owing to suppressed mitochondrial function and elevating LDH level. This oxidative imbalance further leads to dysregulated GLUT expression in hepatocytes, skeletal muscles and white adipose tissue. HFD leads to significant (p < 0.001) upregulation in GLUT 1 and 3 expression while significant (p < 0.001) downregulation in GLUT 2 and 4 expressions in WAT, liver and skeletal muscles. Administration of MLHEF significantly (p < 0.001) reduced the LDH level and also reduces the mitochondrial dysfunction.

CONCLUSION

Imbalances in GLUT levels were significantly reversed in order to maintain GLUT expression in tissues on the administration of MLHEF.

Synthesis of novel coumarin-based thiosemicarbazones and their implications in diabetic management via in-vitro and in-silico approaches

Diabetes mellitus has a high prevalence rate and it has been deemed a severe chronic metabolic disorder with long-term complications. This research aimed to identify compounds that could potentially inhibit the vital metabolic enzyme α-glucosidase and thereby exert an anti-hyperglycemic effect. The main goal was to establish an effective approach to control diabetes. To proceed with this study, a series of novel coumarin-derived thiosemicarbazones 3a-3m was synthesized and examined using a variety of spectroscopic methods. Moreover, all the compounds were subjected to α-glucosidase inhibition bioassay to evaluate their antidiabetic potential. Fortunately, all the compounds exhibited several folds potent α-glucosidase inhibitory activities with IC50 values ranging from 2.33 to 22.11 µM, in comparison to the standard drug acarbose (IC50 = 873.34 ± 1.67 µM). The kinetic studies of compound 3c displayed concentration-dependent inhibition. Furthermore, the binding modes of these molecules were elucidated through a molecular docking strategy which depicted that the thiosemicarbazide moiety of these molecules plays a significant role in the interaction with different residues of the α-glucosidase enzyme. However, their conformational difference is responsible for their varied inhibitory potential. The molecular dynamics simulations suggested that the top-ranked compounds (3c, 3g and 3i) have a substantial effect on the protein dynamics which alter the protein function and have stable attachment in the protein active pocket. The findings suggest that these molecules have the potential to be investigated further as novel antidiabetic medications.

Strain differences in the drug transport capacity of intestinal glucose transporters in Sprague-Dawley versus Wistar rats, C57BL/6J versus Kunming mice

Designing oral drug delivery systems using intestinal glucose transporters (IGTs) may be one of the strategies for improving oral bioavailability of drugs. However, little is known about the biological factors affecting the drug transport capacity of IGTs. Gastrodin is a sedative drug with a structure very similar to glucose. It is a highly water-soluble phenolic glucoside. It can hardly enter the intestine through simple diffusion but exhibits good oral bioavailability of over 80%. We confirmed that gastrodin is absorbed via the intestinal glucose transport pathway. It has the highest oral bioavailability among the reported glycosides' active ingredients through this pathway. Thus, gastrodin is the most selective drug substrate of IGTs and can be used to evaluate the drug transport capacity of IGTs. Obviously, strain is one of the main biological factors affecting drug absorption. This study firstly compared the drug transport capacity of IGTs between SD rats and Wistar rats and between C57 mice and KM mice by pharmacokinetic experiments and single-pass intestinal perfusion experiments of gastrodin. Then, the sodium-dependent glucose transporter type 1 (SGLT1) and sodium-independent glucose transporters type 2 (GLUT2) in the duodenum, jejunum, ileum and colon of these animals were quantified using RT-qPCR and Western blot. The results showed that the oral bioavailability of gastrodin in Wistar rats was significantly higher than in SD rats and significantly higher in KM mice than in C57 mice. Gastrodin absorption significantly differed among different intestinal segments in SD rats, C57 mice and KM mice, except Wistar rats. RT-qPCR and Western blot demonstrated that the intestinal expression distribution of SGLT1 and GLUT2 in SD rats and C57 mice was duodenum ≈ jejunum > ileum > colon. SGLT1 expression did not differ among different intestinal segments in KM mice, whereas the intestinal expression distribution of GLUT2 was duodenum ≈ jejunum ≈ ileum > colon. However, the expression of SGLT1 and GLUT2 did not differ among different intestinal segments in Wistar rats. It was reported that the intestinal expression distribution of SGLT1 and GLUT2 in humans is duodenum > jejunum > ileum > colon. Hence, the intestinal expression distribution of SGLT1 and GLUT2 of SD rats and C57 mice was more similar to that in humans. In conclusion, the drug transport capacity of IGTs differs in different strains of rats and mice. SD rats and C57 mice are more suitable for evaluating the pharmacokinetics of glycosides' active ingredients absorbed via the intestinal glucose transport pathway.

Paliurus spina-christi Mill fruit extracts improve glucose uptake and activate the insulin signaling pathways in HepG2 insulin-resistant cells

BACKGROUND

Paliurus spina-christi Mill. (PSC) fruit is frequently used in the treatment of diabetes mellitus in Mediterranean regions. Here, we investigated the effects of various PSC fruit extracts (PSC-FEs) on glucose consumption and some key mediators of insulin signaling pathways in high glucose and high insulin-induced insulin-resistant HepG2 cells.

METHODS

The effects of methanolic, chloroform and total extracts on cell proliferation were assessed by the MTT assay. The potential of non-toxic extracts on glucose utilization in insulin-resistant HepG2 cells was checked using a glucose oxidase assay. AKT and AMP-activated protein kinase (AMPK) pathway activation and mRNA expression levels of insulin receptor (INSR), glucose transporter 1 (GLUT1), and glucose transporters 4 (GLUT4) were determined by western blotting and real-time PCR, respectively.

RESULTS

We found that high concentrations of methanolic and both low and high concentrations of total extracts were able to enhance glucose uptake in an insulin-resistant cell line model. Moreover, AKT and AMPK phosphorylation were significantly increased by the high strength of methanolic extract, while total extract raised AMPK activation at low and high concentrations. Also, GLUT 1, GLUT 4, and INSR were elevated by both methanolic and total extracts.

CONCLUSIONS

Ultimately, our results shed new light on methanolic and total PSC-FEs as sources of potential anti-diabetic medications, restoring glucose consumption and uptake in insulin-resistant HepG2 cells. These could be at least in part due to re-activating AKT and AMPK signaling pathways and also increased expression of INSR, GLUT1, and GLUT4. Overall, active constituents present in methanolic and total extracts of PCS are appropriate anti-diabetic agents and explain the use of these PSC fruits in traditional medicine for the treatment of diabetes.

Acute and Chronic Glucose Control in Critically Ill Patients With Diabetes: The Impact of Prior Insulin Treatment

BACKGROUND

Emerging data highlight the interactions of preadmission glycemia, reflected by admission HbA1c levels, glycemic control during critical illness, and mortality. The association of preadmission insulin treatment with outcomes is unknown.

METHODS

This observational cohort study includes 5245 patients admitted to the medical-surgical intensive care unit of a university-affiliated teaching hospital. Three groups were analyzed: patients with diabetes with prior insulin treatment (DM-INS, n = 538); patients with diabetes with no prior insulin treatment (DM-No-INS, n = 986); no history of diabetes (NO-DM, n = 3721). Groups were stratified by HbA1c level: <6.5%; 6.5%-7.9% and >8.0%.

RESULTS

Among the three strata of HbA1c, mean blood glucose (BG), coefficient of variation (CV), and hypoglycemia increased with increasing HbA1c, and were higher for DM-INS than for DM-No-INS. Among patients with HbA1c < 6.5%, mean BG ≥ 180 mg/dL and CV > 30% were associated with lower severity-adjusted mortality in DM-INS compared to patients with mean BG 80-140 mg/dL and CV < 15%, (P = .0058 and < .0001, respectively), but higher severity-adjusted mortality among DM-No-INS (P = .0001 and < .0001, respectively) and NON-DM (P < .0001 and < .0001, respectively). Among patients with HbA1c ≥ 8.0%, mean BG ≥ 180 mg/dL was associated with lower severity-adjusted mortality for both DM-INS and DM-No-INS than was mean BG 80-140 mg/dL (p < 0.0001 for both comparisons).

CONCLUSIONS

Significant differences in mortality were found among patients with diabetes based on insulin treatment and HbA1c at home and post-admission glycemic control. Prospective studies need to confirm an individualized approach to glycemic control in the critically ill.

A Synopsis of the Associations of Oxidative Stress, ROS, and Antioxidants with Diabetes Mellitus

The Greek physician, Aretaios, coined the term "diabetes" in the 1st Century A.D. "Mellitus" arose from the observation that the urine exhibits a sweetness due to its elevated glucose levels. Diabetes mellitus (DM) accounted for 6.7 million deaths globally in 2021 with expenditures of USD 966 billion. Mortality is predicted to rise nearly 10-fold by 2030. Oxidative stress, an imbalance between the generation and removal of reactive oxygen species (ROS), is implicated in the pathophysiology of diabetes. Whereas ROS are generated in euglycemic, natural insulin-regulated glucose metabolism, levels are regulated by factors that regulate cellular respiration, e.g., the availability of NAD-linked substrates, succinate, and oxygen; and antioxidant enzymes that maintain the cellular redox balance. Only about 1-2% of total oxygen consumption results in the formation of superoxide anion and hydrogen peroxide under normal reduced conditions. However, under hyperglycemic conditions, about 10% of the respiratory oxygen consumed may be lost as free radicals. Under hyperglycemic conditions, the two-reaction polyol pathway is activated. Nearly 30% of blood glucose can flux through this pathway-a major path contributing to NADH/NAD⁺ redox imbalance. Under these conditions, protein glycation and lipid peroxidation increase, and inflammatory cytokines are formed, leading to the further formation of ROS. As mitochondria are the major site of intracellular ROS, these organelles are subject to the deleterious effects of ROS themselves and eventually become dysfunctional-a milestone in Metabolic Syndrome (MetS) of which insulin resistance and diabetes predispose to cardiovascular disease.

L-type Amino Acid Transporter 1 Utilizing Ferulic Acid Derivatives Show Increased Drug Delivery in the Mouse Pancreas Along with Decreased Lipid Peroxidation and Prostaglandin Production

Oxidative stress and pathological changes of Alzheimer’s disease (AD) overlap with metabolic diseases, such as diabetes mellitus (DM). Therefore, tackling oxidative stress with antioxidants is a compelling drug target against multiple chronic diseases simultaneously. Ferulic acid (FA), a natural antioxidant, has previously been studied as a therapeutic agent against both AD and DM. However, FA suffers from poor bioavailability and delivery. As a solution, we have previously reported about L-type amino acid transporter 1 (LAT1)-utilizing derivatives with increased brain delivery and efficacy. In the present study, we evaluated the pharmacokinetics and antioxidative efficacy of the two derivatives in peripheral mouse tissues. Furthermore, we quantified the LAT1 expression in studied tissues with a targeted proteomics method to verify the transporter expression in mouse tissues. Additionally, the safety of the derivatives was assessed by exploring their effects on hemostasis in human plasma, erythrocytes, and endothelial cells. We found that both derivatives accumulated substantially in the pancreas, with over a 100-times higher area under curve compared to the FA. Supporting the pharmacokinetics, the LAT1 was highly expressed in the mouse pancreas. Treating mice with the LAT1-utilizing derivative of FA lowered malondialdehyde and prostaglandin E₂ production in the pancreas, highlighting its antioxidative efficacy. Additionally, the LAT1-utilizing derivatives were found to be hemocompatible in human plasma and endothelial cells. Since antioxidative derivative 1 was substantially delivered into the pancreas along the previously studied brain, the derivative can be considered as a safe dual-targeting drug candidate in both the pancreas and the brain.

Glycemic control in critically ill patients with or without diabetes

Background

Early randomized controlled trials have demonstrated the benefits of tight glucose control. Subsequent NICE-SUGAR study found that tight glucose control increased mortality. The optimal glucose target in diabetic and nondiabetic patients remains unclear. This study aimed to evaluate the relationship between blood glucose levels and outcomes in critically ill patients with or without diabetes.

Methods

This was a retrospective analysis of the eICU database. Repeat ICU stays, ICU stays of less than 2 days, patients transferred from other ICUs, those with less than 2 blood glucose measurements, and those with missing data on hospital mortality were excluded. The primary outcome was hospital mortality. Generalised additive models were used to model relationship between glycemic control and mortality. Models were adjusted for age, APACHE IV scores, body mass index, admission diagnosis, mechanical ventilation, and use of vasopressor or inotropic agents.

Results

There were 52,107 patients in the analysis. Nondiabetes patients exhibited a J-shaped association between time-weighted average glucose and hospital mortality, while this association in diabetes patients was right-shifted and flattened. Using a TWA glucose of 100 mg/dL as the reference value, the adjusted odds ratio (OR) of TWA glucose of 140 mg/dL was 3.05 (95% confidence interval (CI) 3.03–3.08) in nondiabetes and 1.14 (95% CI 1.08–1.20) in diabetes patients. The adjusted OR of TWA glucose of 180 mg/dL were 4.20 (95% CI 4.07–4.33) and 1.49 (1.41–1.57) in patients with no diabetes and patients with diabetes, respectively. The adjusted ORs of TWA glucose of 80 mg/dL compared with 100 mg/dL were 1.74 (95% CI 1.57–1.92) in nondiabetes and 1.36 (95% CI 1.12–1.66) in patients with diabetes. The glucose ranges associated with a below-average risk of mortality were 80–120 mg/dL and 90–150 mg/dL for nondiabetes and diabetes patients, respectively. Hypoglycemia was associated with increased hospital mortality in both groups but to a lesser extent in diabetic patients. Glucose variability was positively associated with hospital mortality in nondiabetics.

Conclusions

Time-weighted average glucose, hypoglycemia, and glucose variability had different impacts on clinical outcomes in patients with and without diabetes. Compared with nondiabetic patients, diabetic patients showed a more blunted response to hypo- and hyperglycemia and glucose variability. Glycemic control strategies should be reconsidered to avoid both hypoglycemia and hyperglycemia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01769-4.

The Tumor Suppressor Kinase LKB1: Metabolic Nexus

Liver kinase B1 (LKB1) is a multitasking tumor suppressor kinase that is implicated in multiple malignancies such as lung, gastrointestinal, pancreatic, and breast. LKB1 was first identified as the gene responsible for Peutz-Jeghers syndrome (PJS) characterized by hamartomatous polyps and oral mucotaneous pigmentation. LKB1 functions to activate AMP-activated protein kinase (AMPK) during energy stress to shift metabolic processes from active anabolic pathways to active catabolic pathways to generate ATP. Genetic loss or inactivation of LKB1 promotes metabolic reprogramming and metabolic adaptations of cancer cells that fuel increased growth and division rates. As a result, LKB1 loss is associated with increased aggressiveness and treatment options for patients with LKB1 mutant tumors are limited. Recently, there has been new insights into the role LKB1 has on metabolic regulation and the identification of potential vulnerabilities in LKB1 mutant tumors. In this review, we discuss the tumor suppressive role of LKB1 and the impact LKB1 loss has on metabolic reprograming in cancer cells, with a focus on lung cancer. We also discuss potential therapeutic avenues to treat malignancies associated with LKB1 loss by targeting aberrant metabolic pathways associated with LKB1 loss.

Relative Hypoglycemia and Lower Hemoglobin A1c-Adjusted Time in Band Are Strongly Associated With Increased Mortality in Critically Ill Patients

OBJECTIVES

To determine the associations of relative hypoglycemia and hemoglobin A1c-adjusted time in blood glucose (BG) band (HA-TIB) with mortality in critically ill patients.

DESIGN

Retrospective cohort investigation.

SETTING

University-affiliated adult medical-surgical ICU.

PATIENTS

Three thousand six hundred fifty-five patients with at least four BG tests and hemoglobin A1c (HbA1c) level admitted between September 14, 2014, and November 30, 2019.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients were stratified for HbA1c bands of <6.5%; 6.5-7.9%; greater than or equal to 8.0% with optimal affiliated glucose target ranges of 70-140, 140-180, and 180-250 mg/dL, respectively. HA-TIB, a new glycemic metric, defined the HbA1c-adjusted time in band. Relative hypoglycemia was defined as BG 70-110 mg/dL for patients with HbA1c ≥ 8.0%. Further stratification included diabetes status-no diabetes (NO-DM, n = 2,616) and preadmission treatment with or without insulin (DM-INS, n = 352; DM-No-INS, n = 687, respectively). Severity-adjusted mortality was calculated as the observed:expected mortality ratio (O:EMR), using the Acute Physiology and Chronic Health Evaluation IV prediction of mortality. Among NO-DM, mortality and O:EMR, decreased with higher TIB 70-140 mg/dL (p < 0.0001) and were lowest with TIB 90-100%. O:EMR was lower for HA-TIB greater than or equal to 50% than less than 50% and among all DM-No-INS but for DM-INS only those with HbA1 greater than or equal to 8.0%.Among all patients with hba1c greater than or equal to 8.0% And no bg less than 70 mg/dl, mortality was 18.0% For patients with relative hypoglycemia (bg, 70-110 mg/dl) (p < 0.0001) And was 0.0%, 12.9%, 13.0%, And 34.8% For patients with 0, 0.1-2.9, 3.0-11.9, And greater than or equal to 12.0 Hours of relative hypoglycemia (p < 0.0001).

CONCLUSIONS

These findings have considerable bearing on interpretation of previous trials of intensive insulin therapy in the critically ill. Moreover, they suggest that BG values in the 70-110 range may be deleterious for patients with HbA1c greater than or equal to 8.0% and that the appropriate target for BG should be individualized to HbA1c levels. These conclusions need to be tested in randomized trials.

Effect of Hydrolyzed Bird's Nest on β-Cell Function and Insulin Signaling in Type 2 Diabetic Mice

Type 2 diabetes mellitus is characterized by both resistance to the action of insulin and defects in insulin secretion. Bird’s nest, which is derived from the saliva of swiftlets are well known to possess multiple health benefits dating back to Imperial China. However, it’s effect on diabetes mellitus and influence on the actions of insulin action remains to be investigated. In the present study, the effect of standardized aqueous extract of hydrolyzed edible bird nest (HBN) on metabolic characteristics and insulin signaling pathway in pancreas, liver and skeletal muscle of db/db, a type 2 diabetic mice model was investigated. Male db/db diabetic and its euglycemic control, C57BL/6J mice were administered HBN (75 and 150 mg/kg) or glibenclamide (1 mg/kg) orally for 28 days. Metabolic parameters were evaluated by measuring fasting blood glucose, serum insulin and oral glucose tolerance test (OGTT). Insulin signaling and activation of inflammatory pathways in liver, adipose, pancreas and muscle tissue were evaluated by Western blotting and immunohistochemistry. Pro-inflammatory cytokines were measured in the serum at the end of the treatment. The results showed that db/db mice treated with HBN significantly reversed the elevated fasting blood glucose, serum insulin, serum pro-inflammatory cytokines levels and the impaired OGTT without affecting the body weight of the mice in all groups. Furthermore, HBN treatment significantly ameliorated pathological changes and increased the protein expression of insulin, and glucose transporters in the pancreatic islets (GLUT-2), liver and skeletal muscle (GLUT-4). Likewise, the Western blots analysis denotes improved insulin signaling and antioxidant enzyme, decreased reactive oxygen species producing enzymes and inflammatory molecules in the liver and adipose tissues of HBN treated diabetic mice. These results suggest that HBN improves β-cell function and insulin signaling by attenuation of oxidative stress mediated chronic inflammation in the type 2 diabetic mice.

Polyphenolic inhibition of enterocytic starch digestion enzymes and glucose transporters for managing type 2 diabetes may be reduced in food systems

With the current global surge in diabetes cases, there is a growing interest in slowing and managing diabetes and its effects. While there are medications that can be used, they have adverse side effects such as hypoglycemia and weight gain. To overcome these problems, bioactive compounds commonly found in fruits, vegetables and cereal grains are used to slow starch digestion and transport of simple sugars across the intestinal epithelia thereby reducing plasma blood glucose spike. These effects are achieved through inhibition of amylases, glucosidases and glucose transporters present in the gastrointestinal tract and brush boarder membrane. The extent of inhibition by polyphenols is dependent on molecular structure, doses and food matrix. Glycemic lowering effect of polyphenols have been demonstrated both in in vivo and in vitro studies. However, when these compounds are incorporated in food systems, they can interact with other polymers in the food matrix leading to lesser inhibition of digestion and/or glucose transporters compared to isolated or pure compounds as often witnessed in most in vitro studies.

The potent roles of salt-inducible kinases (SIKs) in metabolic homeostasis and tumorigenesis

Salt-inducible kinases (SIKs) belong to AMP-activated protein kinase (AMPK) family, and functions mainly involve in regulating energy response-related physiological processes, such as gluconeogenesis and lipid metabolism. However, compared with another well-established energy-response kinase AMPK, SIK roles in human diseases, especially in diabetes and tumorigenesis, are rarely investigated. Recently, the pilot roles of SIKs in tumorigenesis have begun to attract more attention due to the finding that the tumor suppressor role of LKB1 in non-small-cell lung cancers (NSCLCs) is unexpectedly mediated by the SIK but not AMPK kinases. Thus, here we tend to comprehensively summarize the emerging upstream regulators, downstream substrates, mouse models, clinical relevance, and candidate inhibitors for SIKs, and shed light on SIKs as the potential therapeutic targets for cancer therapies.

Triglyceride Glucose Index and Prognosis of Patients With Ischemic Stroke

Background: The triglyceride glucose index (TyG index) has been proposed as a simple and credible surrogate marker of insulin resistance. However, it is unclear whether TyG index correlates with adverse clinical outcomes in patients with ischemic stroke. Accordingly, this study aimed to explore the relationship between baseline TyG index and clinical outcomes of ischemic stroke individuals. Methods: We included eligible subjects with ischemic stroke from the China National Stroke Registry II for the current analysis. TyG index was calculated and divided into quartiles to explore the relationship with the outcomes of ischemic stroke. Outcomes included stroke recurrence, all-cause mortality, poor functional outcome at 12 months, and neurologic worsening at discharge. Multivariable Cox regression and logistic regression models were performed to explore the correlation of baseline TyG index with the outcomes. Results: Among the 16,310 patients enrolled in the study, the average age was 64.83 ± 11.9 years, and 63.48% were men. The median TyG index was 8.73 (interquartile range, 8.33-9.21). After adjustment for multiple potential covariates, the fourth quartile of TyG index was associated with an increased risk of stroke recurrence (adjusted HR, 1.32; 95% CI, 1.11-1.57; P = 0.002), all-cause mortality (adjusted HR, 1.25; 95%CI, 1.06-1.47; P = 0.01) at 12-month follow-up, and neurological worsening (adjusted OR, 1.26; 95% CI, 1.02-1.55; P = 0.03) at discharge, but not poor functional outcome compared with the first quartile. Conclusion: TyG index representing insulin resistance was associated with an increased risk of stroke recurrence, all-cause mortality, and neurologic worsening in patients with ischemic stroke.

Value of triglyceride-glucose index for the estimation of ischemic stroke risk: Insights from a general population

BACKGROUND AND AIMS

Recent studies have recognized triglyceride-glucose index (TyG) as a practical surrogate of insulin resistance. Previous studies have demonstrated that insulin resistance contributes to ischemic stroke via multiple mechanisms. Our study aimed to investigate the association between TyG and prevalent ischemic stroke, exploring the value of TyG to optimize the risk stratification of ischemic stroke.

METHODS AND RESULTS

This cross-sectional study included 10,900 subjects (mean age: 59.95 years, 59.8% females) from rural areas of northeast China between September 2017 to May 2018. TyG was calculated as ln[fasting triglyceride (mg/dl) × fasting plasma glucose (mg/dl)/2]. The prevalence of ischemic stroke was 5.49%. After adjusting for all covariates, each SD increment of TyG caused 22.8% additional risk for ischemic stroke. When dividing TyG into quartiles, the top quartile had a 1.776 times risk for ischemic stroke against the bottom category. Furthermore, smoothing curve fitting demonstrated this association was linear in the whole range of TyG. Finally, AUC revealed an improvement when introducing TyG into clinical risk factors (0.746 vs 0.751, p = 0.029). Consistently, category-free net reclassification index (0.195, 95% CI: 0.112-0.277, P < 0.001) and integrated discrimination index (0.003, 95% CI: 0.001-0.004, P < 0.001) confirmed the improvement by TyG to stratify ischemic stroke risk.

CONCLUSION

The prevent ischemic stroke correlated proportionally with the increment of TyG, implicating the linearity of TyG as an indicator of ischemic stroke. Our findings suggest the potential value of TyG to optimize the risk stratification of ischemic stroke in a general population.

Comparison of Novel Metabolic Indices in Estimation of Chronic Kidney Diseases in a Southern Chinese Population

BACKGROUND

To determine the optimal cut-off values and evaluate the associations of product of triacylglycerol and glucose (TyG), lipid accumulation product (LAPI), visceral adiposity index (VAI) with chronic kidney diseases (CKD) stratified by sex.

METHODS

From January to April 2018, our team had conducted a large-scale cross-sectional survey that contained 2720 individuals on the southern coast of China. Logistic regression analysis and receiver operating characteristic (ROC) analyses were used to evaluate the optimal cut-off and value of TyG, LAPI, VAI for predicting CKD.

RESULTS

A multivariate logistic regression analysis found that the TyG had the better value of prediction for the presence of CKD for the highest quartile vs the lowest quartile in both males (OR: 3.65; 95% CI, 2.04-6.52; p<0.001) and females (OR: 3.50; 95% CI, 2.20-5.56; p<0.001), followed by LAPI and VAI, when further adjusted for cofounder factors, LAPI and VAI both lost their independence, and only TyG remains its significant association with CKD in both males (OR: 2.81; 95% CI, 1.25-6.30; p<0.001) and females (OR: 3.22; 95% CI, 1.56-6.61; p<0.001). ROC curve showed that TyG had the highest AUC for predicting CKD in males (AUC: 0.618). TyG (AUC: 0.670) and LAPI (AUC: 0.670) both had the highest AUC in females. United predicted models which contain TyG were conducted for predicting CKD in males (AUC: 758) and females (AUC: 0.773) and results indicated that multivariate analysis of TyG and other traditional factors can impressively improve the accuracy of predictive probability for CKD.

CONCLUSION

TyG is a priority to the other two novel indices and may become valuable makers and have strong predictive power for predicting CKD, especially in females.

Usefulness of Triglyceride-glucose Index for estimating Hyperuricemia risk: Insights from a general Population

Objectives: Hyperuricemia is a metabolic abnormality that has cast an enormous burden on global healthcare. Previous studies have revealed the close association between insulin resistance and hyperuricemia. Therefore, monitoring insulin sensitivity may be a possible way to prevent hyperuricemia. Recent studies have demonstrated the usefulness of triglyceride-glucose index (TyG) as a simple surrogate of insulin resistance. Hence, our study aimed to explore the impact of TyG on hyperuricemia and its value to improve the risk stratification and prevention of hyperuricemia. Methods: This cross-sectional study included 6466 subjects (mean age: 59.57 years, 60.19% females) from northeast China between September 2017 to May 2018. TyG was determined as ln[fasting TG(mg/dL)×FPG(mg/dL)/2]. Hyperuricemia was defined as serum uric acid ≥ 357 μmol/L for females and ≥ 417 μmol/L for males. Results: The prevalence of hyperuricemia was 5.24%. In the full model, each SD increment of TyG caused a 12.528 μmol/L elevation of serum urate concentration and a 54.1% additional risk for hyperuricemia. When dividing TyG into quartiles, the top quartile had a 2.730 times risk for hyperuricemia than the bottom one. Moreover, smooth curve fitting demonstrated this association was linear. Additionally, subgroup analysis revealed the association was robust to several risk factors of hyperuricemia. Finally, AUC displayed an improvement when introducing TyG into clinical risk factors (0.751 vs 0.772, p < 0.001), category-free net reclassification index (0.304, 95% CI: 0.195-0.413, P < 0.001) and integrated discrimination index (0.009, 95% CI: 0.004-0.013, P < 0.001) also showed the improvement from TyG. Conclusion: Our work revealed the linear and robust association between TyG and hyperuricemia. Furthermore, our results suggest the importance of simultaneous glycemic and lipids control in the prevention of hyperuricemia. Most importantly, our findings implicate the value of TyG to optimize the risk stratification and prevention of hyperuricemia.

Correlates of Insulin-Stimulated Glucose Disposal in Recent-Onset Type 1 and Type 2 Diabetes

CONTEXT AND OBJECTIVE

Not only type 2 diabetes (T2D), but also type 1 diabetes (T1D), can be associated with insulin resistance, as assessed using insulin-stimulated whole-body glucose disposal (M-value). We hypothesized that different factors would affect the M-value at the onset of T1D and T2D.

DESIGN AND PATIENTS

We examined 132 patients with T1D or T2D matched for sex, age, and body mass index with a known diabetes duration of <12 months. Multivariable linear regression analyses were applied to test the associations between glycemic control, blood lipid levels, adiponectin, and proinflammatory immune mediators and the M-value, obtained from the hyperinsulinemic-euglycemic clamp.

RESULTS

Despite comparable age, body mass index, and near-normoglycemic control, the mean M-value was lower in those with T2D than in those with T1D. Patients with T1D had a lower waist/hip ratio and serum triglycerides but higher serum adiponectin than patients with T2D. However, the circulating proinflammatory markers were not different. Even with adjustments for glucose-lowering treatments, the fasting blood glucose correlated negatively with the M-value in both groups. However, gamma-glutamyl transferase-independently of any treatments-correlated negatively only in T2D. In contrast, serum adiponectin correlated positively with the M-values.

CONCLUSIONS

Fasting glycemia correlated with insulin-stimulated glucose disposal in both diabetes types. However, altered liver and adipose tissue function were associated with insulin-stimulated glucose disposal only in T2D, underpinning the specific differences between these diabetes types.

Estimate of reduced glomerular filtration rate by triglyceride-glucose index: insights from a general Chinese population

Objectives: Recent studies have identified triglyceride-glucose index (TyG) as a surrogate of insulin resistance. Since insulin resistance correlates with renal damage, our study aims to investigate the impact of TyG on the risk of reduced eGFR and explore its value to improve the risk stratification and prevention of reduced eGFR. Methods: This cross-sectional study included 6466 participants (mean age:59.57 years, 60.2% females) from rural areas of northeast China between September 2017 to May 2018. TyG was calculated as ln[fasting triglyceride (mg/dL)×fasting plasma glucose (mg/dL)/2]. Reduced eGFR was defined as eGFR<60ml/min per 1.73m². Results: The prevalence of reduced eGFR was 2.94%. After full adjustment, each SD increase of TyG caused 42.6% additional risk for reduced eGFR. When dividing TyG into quartiles, the top quartile had a 1.934 times risk than the bottom quartile. Furthermore, the risk of reduced eGFR increased linearly with the increment of TyG. Subgroup analysis also revealed the association was robust to several risk factors of renal damage. Finally, category-free net reclassification index (0.204, 95% CI: 0.060-0.349, p = 0.005) and integrated discrimination index (0.010, 95% CI: 0.005-0.016, p < 0.001) demonstrated the value of TyG to refine the risk stratification of reduced eGFR. Conclusion: Our work reveals the robust association between TyG and reduced eGFR. Moreover, the present study implicates the potential role of TyG as a risk indicator to optimize the prevention of reduced eGFR. Lastly, the findings also suggest the importance of simultaneous glycemic and lipid control to avoid the development and progression of reduced eGFR.

High fat diet administration leads to the mitochondrial dysfunction and selectively alters the expression of class 1 GLUT protein in mice

Metabolic syndrome is an agglomeration of disorders including obesity, diabetes and cardiovascular diseases and characterized as chronic mild inflammation which elevates the circulatory inflammatory markers. This could be due to mitochondrial dysfunction, oxidative stress and hypoxia as a consequence of high fat diet (HFD) intake. The present study focuses on the effects of HFD on lactate and mitochondrial metabolism as well as tissue dependent changes in glucose transporter (GLUT) expression in liver, skeletal muscles and adipose tissue of mouse. Lactate dehydrogenase (LDH) and mitochondrial dysfunction established the link between the occurrences of metabolic stress due to HFD. In this work, it was observed that chronic HFD administration aggravated the metabolic alterations by causing reduced ATP production, imbalanced oxidative stress and altered class 1 GLUTs expression. Chronic HFD significantly reduced (p < 0.001) the superoxide dismutase (SOD), catalase (CAT) activities alongside elevated liver injury markers AST and ALT. This in turn causes decreased ATP/ADP ratio, mitochondrial dysfunction and exacerbated LDH levels. This imbalance further led to altered GLUT expression in hepatic cells, adipose tissue and skeletal muscles. HFD significantly (p < 0.001) upregulated the GLUT 1 and 3 expressions while significant downregulated (p < 0.001) GLUT 2 and 4 expression in liver, skeletal muscles and white adipose tissue. These results revealed the link between class 1 GLUTs, mitochondrial dysfunction and HFD-induced metabolic disorder. It can be concluded that HFD impacts mitochondrial metabolism and reprograms tissue-dependent glucose transporter.

Association and interaction between triglyceride-glucose index and obesity on risk of hypertension in middle-aged and elderly adults

AIMS

To investigate the association between triglyceride-glucose(TyG) index and the risk of hypertension.

METHOD

A cross-sectional study was conducted in Bengbu, China. The participants received relevant questionnaire survey, anthropometric tests, and laboratory examination. Multivariate logistic regression analysis was performed to estimate the possible association between TyG index and hypertension risk. The additive interaction evaluated by the relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP), and synergy index(SI) was calculated.

RESULTS

A total of 1777 participants (748 men and 1029 women) were investigated. There was a significant increase in the risk of hypertension and isolated systolic hypertension (ISH) when comparing the highest TyG index (the fourth quartile) to the lowest TyG index (the first quartile) and corresponding ORs were 2.446 (95% CI: 1.746-3.426) and 2.621(95%CI: 1.627-4.224), respectively. However, no significant relationship was observed between TyG index and isolated diastolic hypertension (IDH). In males, significant interactions between TyG index and WHtR (RERI:1.978, 95%CI: 0.162-3.792; AP: 0.359, 0.113-0.605; SI:1.782, 1.017-3.122), smoking (AP: 0.437, 95%CI: 0.048-0.825), family history of hypertension (AP:0.433, 95%CI: 0.203-0.662; SI:2.248, 95%CI: 1.333-3.791) were observed. As for females, there were also significant interactions between TyG index and WHtR (RERI:1.415, 95%CI: 0.693-2.136; AP: 0.198, 95%CI: 0.104-0.291; SI:1.298, 95%CI:1.101-1.530), family history of hypertension (RERI:1.744, 95%CI: 0.221-3.267; AP:0.405, 95%CI: 0.113-0.697) on risk of hypertension.

CONCLUSIONS

Increased TyG index was significantly associated with higher risk of hypertension and ISH, but not for IDH in middle-aged and elderly adults. Our results also demonstrated interactions of TyG index and abdominal obesity and family history of hypertension on hypertension risk.

Saving the sweetness: renal glucose handling in health and disease

Glucose homeostasis is highly controlled, and the function of the kidney plays an integral role in this process. The exquisite control of blood glucose relies, in part, on renal glucose filtration, renal glucose reabsorption, and renal gluconeogenesis. Particularly critical to maintaining glucose homeostasis is the renal reabsorption of glucose; with ~162 g of glucose filtered by the kidney per day, it is imperative that the kidney have the ability to efficiently reabsorb nearly 100% of this glucose back in the bloodstream. In this review, we focus on this central process, highlighting the renal transporters and regulators involved in both the physiology and pathophysiology of glucose reabsorption.