Understanding the link between type 2 diabetes mellitus and Parkinson's disease:role of brain insulin resistance

Type 2 diabetes mellitus and Parkinson's disease are chronic diseases linked to a growing pandemic that affects older adults and causes significant socio-economic burden.Epidemiological data supporting a close relationship between these two aging-related diseases have resulted in the investigation of shared pathophysiological molecular mechanisms.Impaired insulin signaling in the brain has gained increasing attention during the last decade and has been suggested to contribute to the development of Parkinson's disease through the dysregulation of several pathological processes.The contribution of type 2 diabetes mellitus and insulin resistance in neurodegeneration in Parkinson's disease,with emphasis on brain insulin resistance,is extensively discussed in this article and new therapeutic strategies targeting this pathological link are presented and reviewed.

Efficacy,safety and treatment satisfaction of transition to a regimen of insulin degludec/aspart:A pilot study

BACKGROUND There is a lack of clinical evidence on the efficacy and safety of transitioning from a thrice-daily pre-mixed insulin or basal-prandial regimen to insulin degludec/aspart(IDegAsp)therapy,with insufficient data from the Chinese population.AIM To demonstrate the efficacy,safety,and treatment satisfaction associated with the transition to IDegAsp in type 2 diabetes mellitus(T2DM).METHODS In this 12-week open-label,non-randomized,single-center,pilot study,patients with T2DM receiving thrice-daily insulin or intensive insulin treatment were transitioned to twice-daily injections of insulin IDegAsp.Insulin doses,hemoglobin A1c(HbA1c)levels,fasting blood glucose(FBG),hypoglycemic events,a Diabetes Treatment Satisfaction Questionnaire,and other parameters were assessed at baseline and 12-weeks.RESULTS This study included 21 participants.A marked enhancement was observed in the FBG level(P=0.02),daily total insulin dose(P=0.03),and overall diabetes treatment satisfaction(P<0.01)in the participants who switched to IDegAsp.There was a decrease in HbA1c levels(7.6±1.1 vs 7.4±0.9,P=0.31)and the frequency of hypoglycemic events of those who switched to IDegAsp decreased,however,there was no statistically significant difference.CONCLUSION The present findings suggest that treatment with IDegAsp enhances clinical outcomes,particularly FBG levels,daily cumulative insulin dose,and overall satisfaction with diabetes treatment.

Transient extreme insulin resistance in a critically ill patient:A case report

BACKGROUND Acute hyperglycemia due to insulin resistance is common in critically ill patients,typically managed with insulin infusion.However,the occurrence of transient extreme insulin resistance(EIR)requiring exceptional high-dose insulin is rare.CASE SUMMARY We present the case of a 68-year-old woman with pneumonia who suffered an out-of-hospital cardiac arrest,subsequently developing transient EIR following a new episode of sepsis.Remarkably,insulin resistance rapidly reversed when the insulin infusion rate peaked at 960 units/hour(a total of 18224 units on that day),and it was promptly titrated down to zero upon achieving the target glucose level.CONCLUSION Exceptional high-dose insulin infusion may be required in critically ill patients with stress-related EIR,which is typically transient.Clinicians should be aware of the phenomenon and cautious to avoid hypoglycemia and fluid overload during the steep titration of high-dose insulin infusion.

Premixed insulin: Advantages, disadvantages, and future

Premixed insulin combines two types of insulin in a single injection.This combination streamlines dosing for patients with type 1 or type 2 diabetes,thereby enhancing convenience.However,patients receiving premixed insulin commonly have less satisfactory blood glucose control.The fixed ratio of insulin in these formulations frequently fails to account for the nuanced demands of individualized glucose-lowering therapy.Moreover,local absorption of mixed insulin and potential systemic autoimmune responses may further compromise glycaemic control.The co-formulation of insulin degludec and insulin aspart introduces a new combination of the two insulin types within a single injection,offering a promising solution for mitigating the limitations inherent in premixed insulin.

Insulin-induced severe thyrotoxic periodic paralysis:A case report

BACKGROUND Thyrotoxic periodic paralysis(TPP)is an endocrine emergency caused by thyrotoxicosis,manifesting mainly as periodic myasthenia and hypokalemia,and posing a serious threat to the patient's health.Fatigue,strenuous exercise,alcohol abuse,high carbohydrate intake and insulin injections are common triggers of paralysis.This article reports a case of severe TPP induced by insulin injection,elucidates the characteristics and pathogenesis of the disease,analyses the risk factors for triggering TPP,and hopefully provides more clinical data for TPP patients.CASE SUMMARY A 38-year-old Asian man presented to the emergency department with a oneweek history of limb weakness and worsening half-day.His medical history included poorly controlled type 2 diabetes and he had been switched to Aspart50 a week earlier.He was alert and oriented with upper extremity strength grade 3 and lower extremity strength grade 1.Emergency department tests showed hypokalemia of 1.6 mmol/L.The paramedics administered 1.5 g of potassium intravenously,followed by 4.0 g orally.Weakness in the arms and legs improved.He was referred to endocrinology where he was diagnosed with Graves'disease,with suboptimal control and insulin injections possibly causing TPP.We stopped his insulin and he was discharged with a potassium level of 4.0 mmol/L.CONCLUSION Insulin is a trigger for TPP and should be avoided in patients with hyperthyroidism.Early recognition and treatment of TPP is crucial,especially in patients presenting with hypokalemic periodic paralysis.

Selenoprotein P1 as a biomarker of insulin resistance in pediatric obesity:Insights and implications

This editorial discusses the findings of Elbarky et al on the role of selenoprotein P1(SEPP1)in pediatric obesity and insulin resistance.Their study uncovered si-gnificantly lower SEPP1 Levels in children who were obese compared with hea-lthy peers,demonstrating a negative correlation between SEPP1 levels and mea-sures of adiposity and insulin resistance.These findings suggest that SEPP1 is a biomarker useful in the early identification of insulin resistance in pediatric populations.This editorial emphasizes the clinical implications of the study and calls for further research to validate and explore the role of SEPP1 in metabolic health.

Research Progress of Massage Therapy for Obesity-Induced Insulin Resistance

By searching the relevant literature in recent ten years,this paper summarizes the research progress of massage in the treatment of obesity-induced insulin resistance,in order to provide more basis for massage in the treatment of obesity-induced insulin resistance.

Insulin autoantibodies,D-dimer and microalbuminuria:A crosssectional,case-control study of type 2 diabetes

BACKGROUND Type 2 diabetes mellitus(T2DM)often leads to vascular complications,such as albuminuria.The role of insulin autoantibodies(IAA)and their interaction with D-dimer in this context remains unclear.AIM To investigate the characteristics of IAA and its effect on albuminuria in T2DM patients.METHODS We retrospectively analyzed clinical data from 115 T2DM patients with positive IAA induced by exogenous insulin,and 115 age-and sex-matched IAA-negative T2DM patients as controls.Propensity scores were calculated using multivariate logistic regression.Key variables were selected using the least absolute shrinkage and selection operator(LASSO)algorithm.We constructed a prediction model and analyzed the association between IAA and albuminuria based on demographic and laboratory parameters.RESULTS The IAA-positive group had significantly higher D-dimer levels[0.30(0.19-0.55)mg/L vs 0.21(0.19-0.33)mg/L,P=0.008]and plasma insulin levels[39.1(12.0-102.7)μU/mL vs 9.8(5.5-17.6)μU/mL,P<0.001]compared to the IAA-negative group.Increases in the insulin dose per weight ratio,diabetes duration,and urinary albumin-to-creatinine ratio(UACR)were observed but did not reach statistical significance.The LASSO model identified plasma insulin and D-dimer as key factors with larger coefficients.D-dimer was significantly associated with UACR in the total and IAA-positive groups but not in the IAA-negative group.The odds ratio for D-dimer elevation(>0.5 g/L)was 2.88(95%confidence interval:1.17-7.07)in the IAA-positive group(P interaction<0.05).CONCLUSION D-dimer elevation is an independent risk factor for abnormal albuminuria and interacts with IAA in the development of abnormal albuminuria in T2DM patients.

Impact of setting distinct target blood glucose levels on endogenous insulin suppression and pharmacodynamics of insulin preparations

BACKGROUND Insulin therapy plays a crucial role in managing diabetes.Regulatory guidelines mandate assessing the pharmacokinetics(PK)and pharmacodynamics(PD)of new insulin formulations with euglycemic clamp techniques before entry into the market.Typically,blood glucose(BG)levels are maintained at 5%below baseline to suppress endogenous insulin secretion in healthy volunteers.However,in scenarios where BG baseline is relatively low,maintaining it at 5%below baseline can increase hypoglycemic risk.Consequently,we adjusted to maintain it at 2.5%below a baseline of<4.00 mmol/L.It remains uncertain whether this adjustment impacts endogenous insulin inhibition or the PD of study insulin.AIM To evaluate and compare the PD and C-peptide status using two different target BG setting methods.METHODS Data came from euglycemic clamp trials assessing the PK/PD of insulin aspart(IAsp)in healthy participants.Target BG was set at 2.5%below baseline for those with a basal BG of<4.00 mmol/L(group A),and at 5%below baseline for others(group B).The area under the curve(AUC)of IAsp(AUC_(IAsp,0-8 h))and GIR from 0 to 8 hours(AUCGIR,0-8 h)was used to characterize the PK and PD of IAsp,respectively.The C-peptide reduction and PK/PD of IAsp were compared between the two groups.RESULTS Out of 135 subjects,15 were assigned to group A and 120 to group B;however,group B exhibited higher basal Cpeptide(1.59±0.36 vs 1.32±0.42 ng/mL,P=0.006).Following propensity score matching to adjust for basal Cpeptide differences,71 subjects(15 in group A and 56 in group B)were analyzed.No significant differences were observed in demographics,IAsp dosage,or clamp quality.Group B showed significantly higher baseline(4.35±0.21 vs 3.91±0.09 mmol/L,P<0.001),target(4.13±0.20 vs 3.81±0.08 mmol/L,P<0.001),and clamped(4.10±0.17 vs 3.80±0.06 mmol/L,P<0.001)BG levels.Both groups exhibited comparable C-peptide suppression(32.5%±10.0%vs 35.6%±12.1%,P=0.370)and similar IAsp activity(AUCGIR,0-8 h:1433±400 vs 1440±397 mg/kg,P=0.952)under nearly equivalent IAsp exposure(AUC_(IAsp,0-8 h):566±51 vs 571±85 ng/mL×h,P=0.840).CONCLUSION Maintaining BG at 2.5%below a baseline of<4.00 mmol/L did not compromise the endogenous insulin suppression nor alter the observed pharmacodynamic effects of the study insulin.

Tacrolimus induces insulin receptor substrate 1 hyperphosphorylation and inhibits mTORc1/S6K1 cascade in HL7702 cells

BACKGROUND Tacrolimus(FK506)is a key calcineurin inhibitor used to prevent organ transplant rejection and is effective in improving graft survival.However,it is linked to hyperglycemia and insulin resistance,contributing to new-onset diabetes after transplantation and negatively affecting islet function.AIM To study the effects of tacrolimus on the insulin signaling pathway of hepatocytes.METHODS HL7702 cells were treated with different concentrations of tacrolimus(0.1 mg/L,1 mg/L,5 mg/L)for 24 hours.The proteins involved in insulin signaling were detected by Western blotting.RESULTS Compared with the control group,phosphorylation of insulin receptor substrate(IRS)1 at Ser 307 and Ser 323 were increased significantly when the tacrolimus concentration reached 1 and 5 mg/L.Phosphorylation of IRS1 at Ser 1101 was also increased,although not significantly.However,phosphorylation of Ribosomal protein S6 kinase beta-1 at Thr 389 was decreased significantly.The levels of phosphorylated glycogen synthase kinase 3αSer 21 and Ser 9 were increased.Surprisingly,phosphorylation of glycogen synthase at Ser 641 was increased.There was no significant change in the activity of glycogen phosphorylase.CONCLUSION Tacrolimus has no direct effect on hepatic glucose metabolism,but inhibits IRS1-mediated insulin signaling.This may be one of the underlying mechanisms by which tacrolimus induces insulin resistance.

Exogenous insulin autoimmune syndrome:A case report and review of literature

BACKGROUND Insulin autoimmune syndrome(IAS)is a severe manifestation of spontaneous hypoglycemia.It is characterized by elevated levels of immune-reactive insulin and highly potent insulin autoantibodies(IAAs),which are induced by endogenous insulin circulating in the bloodstream.It is distinguished by recurring instances of spontaneous hypoglycemia,the presence of IAA within the body,a substantial elevation in serum insulin levels,and an absence of prior exogenous insulin administration.Nevertheless,recent studies show that both conventional insulin and its analogs can induce IAS episodes,giving rise to the notion of nonclassical IAS.Therefore,more attention should be paid to these diseases.CASE SUMMARY In this case report,we present a rare case of non-classical IAS in an 83-year-old male patient who present with symptoms of a psychiatric disorder.Upon symptom onset,the patient exhibited Whipple's triad(including hypoglycemia,blood glucose level less than 2.8 mmol/L during onset,and rapid relief of hypoglycemic symptoms after glucose administration).Concurrently,his serum insulin level was significantly elevated,which contradicted his C-peptide levels.After a comprehensive examination,the patient was diagnosed with exogenous insulin autoimmune syndrome.Considering that the patient had type 2 diabetes mellitus and a history of exogenous insulin use before disease onset,it was presumed that non classical IAS was induced by this condition.The PubMed database was used to search for previous cases of IAS and non-classical IAS to analyze their characteristics and treatment approaches.CONCLUSION The occurrence of non-classical IAS is associated with exogenous insulin or its analogs,as well as with sulfhydryl drugs.Symptoms can be effectively alleviated through the discontinuation of relevant medications,administration of hormones or immunosuppressants,plasma exchange,and lifestyle adjustments.

Mannogalactoglucan from mushrooms protects pancreatic islets via restoring UPR and promotes insulin secretion in TIDM mice

Type 1 diabetes mellitus(T1DM) lacks insulin secretion due to autoimmune deficiency of pancreaticβ-cells.Protecting pancreatic islets and enhancing insulin secretion has been therapeutic approaches.Mannogalactoglucan is the main type of polysaccharide from natural mushroom,which has potential medicinal prospects.Nevertheless,the antidiabetic property of mannogalactoglucan in T1DM has not been fully elucidated.In this study,we obtained the neutral fraction of alkali-soluble Armillaria mellea polysaccharide(AAMP-N) with the structure of mannogalactoglucan from the fruiting body of A.mellea and investigated the potential therapeutic value of AAMP-N in T1DM.We demonstrated that AAMP-N lowered blood glucose and improved diabetes symptoms in T1DM mice.AAMP-N activated unfolded protein response(UPR) signaling pathway to maintain ER protein folding homeostasis and promote insulin secretion in vivo.Besides that,AAMP-N promoted insulin synthesis via upregulating the expression of transcription factors,increased Ca^(2+) signals to stimulate intracellular insulin secretory vesicle transport via activating calcium/calmodulin-dependent kinase Ⅱ(CamkⅡ) and cAMP/PKA signals,and enhanced insulin secretory vesicle fusion with the plasma membrane via vesicle-associated membrane protein 2(VAMP2).Collectively,these studies demonstrated that the therapeutic potential of AAMP-N on pancreatic islets function,indicating that mannogalactoglucan could be natural nutraceutical used for the treatment of T1DM.

Association between glucose-lowering drugs and circulating insulin antibodies induced by insulin therapy in patients with type 2 diabetes

BACKGROUND Insulin antibodies(IAs)affect blood glucose control in patients receiving insulin therapy.AIM To investigate the relationship between different hypoglycemic treatments and IAs in patients with type 2 diabetes mellitus(T2DM).METHODS This cross-sectional,retrospective study included 1863 patients with T2DM who were receiving exogenous insulin therapy.All patients received stable antidiabetic therapy in the last 3 months and IA levels were measured using an iodine-125 array.RESULTS A total of 1863 patients were enrolled.There were 902(48.4%)patients who had positive IAs(IA level>5%),with a mean IA level of 11.06%(10.39%-11.72%).IA levels were positively correlated with high fasting blood glucose(odds ratio=1.069,P<0.001).The proportion of positive IAs was lowest in patients using glargine only(31.9%)and highest in patients using human insulin only(70.3%),P<0.001.The IA levels in patients using sulfonylureas/glinides(8.3%),metformin(9.6%),and dipeptidyl peptidase-4 inhibitors(8.2%)were all lower than in patients without these drugs(all P<0.05).CONCLUSION Nearly half of patients on insulin therapy have positive IA antibodies,and IA antibody levels are associated with blood glucose control.Insulin glargine and a combination of oral glucose-lowering drugs were correlated with lower IA levels.

Amylase intrapancreatic infusion delays insulin release during an intravenous glucose tolerance test,proof of acini–islet–acinar interactions

BACKGROUND The possible existence of an acini–islet–acinar(AIA)reflex,involving mutual amylase and insulin interactions,was investigated in the current acute experiment on pigs.AIM To confirm the existence of an AIA reflex and justify the placement of the exocrine and endocrine pancreatic components within the same organ.METHODS The study was performed on six pigs under general anesthesia.An intravenous glucose tolerance test was performed,with a bolus infusion of 50%glucose to the jugular vein,while amylase(5000 U/kg)or vehicle intrapancreatic infusions were administered via the pancreaticoduodenalis cranialis artery during 30 min with a 1 mL/min flow rate.RESULTS The amylase infusion to pancreatic arterial circulation inhibited and delayed the insulin release peak which is usually associated with the highest value of blood glucose and is typically observed at 15 min after glucose infusion,for>1 h.The intrapancreatic infusion of the vehicle(saline)did not have any effect on the time frame of insulin release.Infusion of 1%bovine serum albumin changed the insulin release curve dramatically and prolonged the high range of insulin secretion,far beyond the glucose peak.CONCLUSION Intrapancreatic arterial infusion of amylase interrupted the integrated glucose–insulin interactions.This confirms an AIA reflex and justifies placement of the exocrine and endocrine pancreatic components within the same organ.

Novel insights into D-Pinitol based therapies:a link between tau hyperphosphorylation and insulin resistance

Alzheimer’s disease is a neurodegenerative disorder characterized by the amyloid accumulation in the brains of patients with Alzheimer’s disease.The pathogenesis of Alzheimer’s disease is mainly mediated by the phosphorylation and aggregation of tau protein.Among the multiple causes of tau hyperphosphorylation,brain insulin resistance has generated much attention,and inositols as insulin sensitizers,are currently considered candidates for drug development.The present narrative review revises the interactions between these three elements:Alzheimer’s disease-tau-inositols,which can eventually identify targets for new disease modifiers capable of bringing hope to the millions of people affected by this devastating disease.

Insulin resistance as the molecular link between diabetes and Alzheimer's disease

Diabetes mellitus(DM)and Alzheimer's disease(AD)are two major health concerns that have seen a rising prevalence worldwide.Recent studies have indicated a possible link between DM and an increased risk of developing AD.Insulin,while primarily known for its role in regulating blood sugar,also plays a vital role in protecting brain functions.Insulin resistance(IR),especially prevalent in type 2 diabetes,is believed to play a significant role in AD's development.When insulin signalling becomes dysfunctional,it can negatively affect various brain functions,making individuals more susceptible to AD's defining features,such as the buildup of beta-amyloid plaques and tau protein tangles.Emerging research suggests that addressing insulin-related issues might help reduce or even reverse the brain changes linked to AD.This review aims to explore the relationship between DM and AD,with a focus on the role of IR.It also explores the molecular mechanisms by which IR might lead to brain changes and assesses current treatments that target IR.Understanding IR's role in the connection between DM and AD offers new possibilities for treatments and highlights the importance of continued research in this interdisciplinary field.

Possible roles of insulin, IGF-1 and IGFBPs in initiation and progression of colorectal cancer

AIM: To investigate the roles of serum insulin, insulin-like growth factor-1 (IGF-1), and insulin-like growth factor binding proteins (IGFBPs) in the initiation and progression of colorectal cancer.

Selenoprotein-p and insulin resistance in children and adolescents with obesity

BACKGROUND Insulin resistance and obesity present significant challenges in pediatric populations.Selenoprotein P1(SEPP1)serves as a biomarker for assessing selenium levels in the body.While its association with metabolic syndrome is established in adults,its relevance in children remains underexplored.AIM To ascertain SEPP1 blood levels in children and adolescents diagnosed with obesity and to assess its correlation with insulin resistance and adiposity indices.METHODS 170 children participated in this study,including 85 diagnosed with obesity and an equal number of healthy counterparts matched for age and sex.Each participant underwent a comprehensive medical evaluation,encompassing a detailed medical history,clinical examination,and anthropometric measurements like waist circumference and waist-to-height ratio.Furthermore,routine blood tests were conducted,including serum SEPP1,visceral adiposity index(VAI),and Homeostatic Model Assessment of Insulin Resistance(HOMA-IR)level.RESULTS Our findings revealed significantly lower serum SEPP1 levels in children with obesity compared to their healthy peers.Moreover,notable negative correlations were observed between serum SEPP1 levels and body mass index,VAI,and HOMA-IR.CONCLUSION The study suggests that SEPP1 could serve as a valuable predictor for insulin resistance among children and adolescents diagnosed with obesity.This highlights the potential utility of SEPP1 in pediatric metabolic health assessment and warrants further investigation.

Diet restriction and exercise alleviate cognitive reduction of high fat diet (HFD)-induced obese mice by rescuing inflammation-mediated compromised insulin signaling pathway through activating AMPK/SIRT1 signal pathway and suppressing TLR4 signal pathway

Obesity,caused by excessive energy,leads to body weight gain and various diseases,including cognitive impairment.Current studies suggest that diet restriction such as optimal fasting and regular exercise are crucial for improving cognitive capacity.However,further exploration is needed to understand the specific mechanisms of high fat diet(HFD)-induced cognitive decline in obesity.In the present study,4-month-old mice were subjected to HFD feeding for 18 weeks,followed by aerobic exercise and high-intensity intermittent exercise,regular diet feeding,and intermittent fasting for 8 weeks,and then used to evaluate cognitive capacity,inflammation,compromised insulin signaling pathway,and apoptosis in hippocampal tissue,as well as AMPK/SIRT1 and TLR4 signal pathways.Obese mice revealed impaired cognitive capacity as compared with mice fed with regular diets.In contrast,aerobic exercise,high-intensity intermittent exercise,regular diet,and intermittent fasting could inhibit apoptosis caused by inflammation-mediated compromised insulin signaling pathway in hippocampal tissues through activating the AMPK/SIRT1 signal pathway and suppressing the TLR4 signal pathway,thereby rescuing the cognitive impairment of obese mice.Therefore,diet restriction and exercise interventions may play a positive role in reverting obesity-induced cognitive impairment.

Palmitoleic acid on top of HFD ameliorates insulin resistance independent of diacylglycerols and alters gut microbiota in C57BL/6J mice

With the prevalence of obesity and obesity-related metabolic syndrome,such as insulin resistance in recent years,it is urgent to explore effective interventions to prevent the progression of obesity-related metabolic syndrome.Palmitoleic acid is a monounsaturated fatty acid that is available from dietary sources,mainly derived from marine products.P almitoleic acid plays a positive role in maintaining glucose homeostasis and reducing inflammation.However,it is still unknow the mechanism of palmitoleic acid in ameliorating insulin resistance.Here,we investigated the effects of palmitoleic acid on chow diet(CD)-fed and high-fat diet(HFD)-fed mice,which were fed CD or HFD for 12 weeks before administration.We administrated mice with BSA(control),oleic acid,or palmitoleic acid for 6 weeks on top of CD or HFD feeding.We found that palmitoleic acid only improved glucose homeostasis in HFD-fed obese mice by increasing glucose clearance and reducing HOMA-IR.Further study explored that palmitoleic acid changed the composition of gut microbiota by decreasing Firmicutes population and increasing Bacteroidetes population.In colon,palmitoleic acid increased intestinal tight junction integrity and reduced inflammation.Moreover,palmitoleic acid decreased macrophage infiltration in liver and adipose tissue and increase glucose uptake in adipose tissue.Diacylglycerol(DAG)in tissue(for example,liver)is found to positively correlated with HOMA-IR.HFD enhanced the levels of DAGs in liver but not in adipose tissue in this study.Palmitoleic acid did not reverse the high DAG levels induced by HFD in liver.Therefore,in HFD-fed mice,palmitoleic acid reduced insulin resistance by an independent-manner of DAGs.It might be associated with the beneficial effects of palmitoleic acid on altering the gut microbiota composition,improving of intestinal barrier function,and downregulating the inflammation in colon,liver,and adipose tissue.