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.

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.

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.

Ghrelin regulates insulin resistance by targeting insulin-like growth factor-1 receptor via miR-455-5p in hepatic cells

Objective: To explore the mechanism by which ghrelin regulates insulin sensitivity through modulation of miR-455-5p in hepatic cells. Methods: HepG2 cells were treated with or without DAG (1 μM). Glucose consumption, intracellular glycogen content, phosphorylation of PI3K and Akt stimulated by insulin, expression of miR-455-5p, as well as IGF-1R protein level were analyzed. In addition, bioinformatic analysis, dual luciferase reporter assay, miR- 455-5p mimic or inhibitor treatment was conducted to investigate the molecular mechanisms. Results: High glucose treatment upregulated miR-455-5p expression but reduced glucose consumption and glycogen content. DAG reversed the effect of high glucose on glucose metabolism, increased protein level of IGF-1R and phosphorylation of PI3K/Akt stimulated by insulin, as well as downregulated miR-455-5p expression. Bioinformatic analysis indicated IGF-1R was the target of miR-455-5p. Dual luciferase reporter assay, as well as transfection with miR-455-5p mimic/inhibitor confirmed that DAG activated IGF-1R/PI3K/Akt signaling via inhibiting miR-455-5p. Conclusion: DAG improves insulin resistance via miR-455-5p- mediated activation of IGF-1R/PI3K/Akt system, suggesting that suppression of miR-455-5p or activation of DAG may be potential targets for T2DM therapy.

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.

miRNA-103: Molecular link between insulin resistance and nonalcoholic fatty liver disease

AIM: To investigate the associations between miRNA-103(mi R-103) and insulin resistance and nonalcoholic fatty liver disease(NAFLD).METHODS: Serum samples were collected from 50 NAFLD patients who were overweight or obese(NAFLD group) and from 30 healthy subjects who served as controls(normal control group). Quantitative polymerasechain reaction was used to detect expression of mi R-103. Fasting plasma glucose, fasting insulin, and triglyceride(TG) levels were measured. Homeostasis model assessment was used to evaluate basal insulin resistance(HOMA-IR). Patient height and weight were measured to calculate body mass index(BMI).RESULTS: Compared with the normal control group, higher serum levels of mi R-103 were expressed in the NAFLD group(8.18 ± 0.73 vs 4.23 ± 0.81, P = 0.000). When P = 0.01(bilateral), mi R-103 was positively correlated with HOMA-IR(r = 0.881), TG(r = 0.774) and BMI(r = 0.878), respectively. mi R-103, TG and BMI were all independent factors for HOMAIR(β = 0.438/0.657/0.251, P = 0.000/0.007/0.001). mi R-103, TG, BMI and HOMA-IR were all risk factors for NAFLD(odds ratio = 2.411/16.196/1.574/19.11, P = 0.009/0.022/0.01/0.014).CONCLUSION: mi R-103 is involved in insulin resistance and NAFLD, and may be a molecular link between insulin resistance and NAFLD and a therapeutic target for these disorders.

Importance of hepatitis C virus-associated insulin resistance:Therapeutic strategies for insulin sensitization

Insulin resistance is one of the pathological features in patients with hepatitis C virus(HCV) infection.Generally,persistence of insulin resistance leads to an increase in the risk of life-threatening complications such as cardiovascular diseases.However,these complications are not major causes of death in patients with HCV-associated insulin resistance.Indeed,insulin resistance plays a crucial role in the development of various complications and events associated with HCV infection.Mounting evidence indicates that HCV-associated insulin resistance may cause(1) hepatic steatosis;(2) resistance to anti-viral treatment;(3) hepatic f ibrosis and esophageal varices;(4) hepatocarcinogenesis and proliferation of hepatocellular carcinoma;and(5) extrahepatic manifestations.Thus,HCV-associated insulin resistance is a therapeutic target at any stage of HCV infection.Although the risk of insulin resistance in HCV-infected patients has been documented,therapeutic guidelines for preventing the distinctive complications of HCV-associated insulin resistance have not yet been established.In addition,mechanisms for the development of HCV-associated insulin resistance differ from lifestyle-associated insulin resistance.In order to ameliorate HCV-associated insulin resistance and its complications,the eff icacy of the following interventions is discussed:a late evening snack,coffee consumption,dietary iron restriction,phlebotomy,and zinc supplements.Little is known regarding the effect of anti-diabetic agents on HCV infection,however,a possible association between use of exogenous insulin or a sulfonylurea agent and the development of HCC has recently been reported.On the other hand,insulin-sensitizing agents are reported to improve sustained virologic response rates.In this review,we summarize distinctive complications of,and therapeutic strategies for,HCVassociated insulin resistance.Furthermore,we discuss supplementation with branched-chain amino acids as a unique insulin-sensitizing strategy for patients with HCVassociated insulin resistance.

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.

Hepatitis C virus infection and insulin resistance

Approximately 170 million people worldwide are chronically infected with hepatitis C virus(HCV).Chronic HCV infection is the leading cause for the development of liver fibrosis,cirrhosis,hepatocellular carcinoma(HCC)and is the primary cause for liver transplantation in the western world.Insulin resistance is one of the pathological features in patients with HCV infection and often leads to development of typeⅡdiabetes.Insulin resistance plays an important role in the development of various complications associated with HCV infection.Recent evidence indicates that HCV associated insulin resistance may result in hepatic fibrosis,steatosis,HCC and resistance to anti-viral treatment.Thus,HCV associated insulin resistance is a therapeutic target at any stage of HCV infection.HCV modulates normal cellular gene expression and interferes with the insulin signaling pathway.Various mechanisms have been proposed in regard to HCV mediated insulin resistance,involving up regulation of inflammatory cytokines,like tumor necrosis factor-α,phosphorylation of insulin-receptor substrate-1,Akt,up-regulation of gluconeogenic genes like glucose 6 phosphatase,phosphoenolpyruvate carboxykinase 2,and accumulation of lipid droplets.In this review,we summarize the available information on how HCV infection interferes with insulin signaling pathways resulting in insulin resistance.

Diabetes mellitus, insulin resistance and hepatitis C virus infection: A contemporary review

To summarise the literature data on hepatitis C virus (HCV)-infected patients concerning the prevalence of glucose abnormalities and associated risk.METHODSWe conducted a PubMed search and selected all studies found with the key words 'HCV' or 'hepatitis C virus' and 'diabetes' or 'insulin resistance'. We included only comparative studies written in English or in French, published from January 2000 to April 2015. We collected the literature data on HCV-infected patients concerning the prevalence of glucose abnormalities [diabetes mellitus (DM) and insulin resistance (IR)] and associated risk [i.e., severe liver fibrosis, response to antivirals, and the occurrence of hepatocellular carcinoma (HCC)].RESULTSHCV infection is significantly associated with DM/IR compared with healthy volunteers and patients with hepatitis B virus infection. Glucose abnormalities were associated with advanced liver fibrosis, lack of sustained virologic response to interferon alfa-based treatment and with a higher risk of HCC development. As new antiviral therapies may offer a cure for HCV infection, such data should be taken into account, from a therapeutic and preventive point of view, for liver and non-liver consequences of HCV disease. The efficacy of antidiabetic treatment in improving the response to antiviral treatment and in decreasing the risk of HCC has been reported by some studies but not by others. Thus, the effects of glucose abnormalities correction in reducing liver events need further studies.CONCLUSIONGlucose abnormalities are strongly associated with HCV infection and show a negative impact on the main liver related outcomes.

Association of chronic viral hepatitis B with insulin resistance

AIM:To investigate the relationship between chronic viral hepatitis B(CVHB) and insulin resistance(IR) in Korean adults.METHODS:A total of 7880 adults(3851 men,4029 women) who underwent a comprehensive medical examination were enrolled in this study.Subjects diagnosed with either diabetes mellitus,or any other disorder that could influence their insulin sensitivity,were rejected.Anthropometry,metabolic risk factors,hepatitis B surface antigen,hepatitis B surface antibody,hepatitis B core antibody,fasting plasma glucose and insulin were measured for all subjects.Homeostasis model assessment(HOMA),quantitative insulin check index(QUICKI),and Mf fm index were used for determining insulin sensitivity.Each participant was categorized into a negative,recovery,or CVHB group.To compare variables between groups,a t-test and/or one-way analysis of variance were used.Partial correlation coefficients were computed to present the association between insulin resistance and other variables.Multiple logistic regression analysis was used to assess the independent association between CVHB and IR.RESULTS:The mean age of men and women were 48.9 and 48.6 years,respectively.Subjects in the CVHB group had significantly higher waist circumference [(86.0 ± 7.7 cm vs 87.3 ± 7.8 cm,P = 0.004 in men),(78.3 ± 8.6 cm vs 80.5 ± 8.5 cm,P < 0.001 in women)],cystatin C [(0.96 ± 0.15 mg/dL vs 1.02 ± 0.22 mg/dL,P < 0.001 in men),(0.84 ± 0.15 mg/dL vs 0.90 ± 0.16 mg/dL,P < 0.001 in women)],fasting insulin [(5.47 ± 3.38 U/mL vs 6.12 ± 4.62 U/mL,P < 0.001 in men),(4.57 ± 2.82 U/mL vs 5.06 ± 3.10 U/mL,P < 0.001 in women)] and HOMA index [(1.24 ± 0.86 vs 1.43 ± 1.24,P < 0.001 in men),(1.02 ± 0.76 vs 1.13 ± 0.87,P = 0.033 in women)] compared to control group.The HOMA index revealed a positive correlation with body mass index(BMI)(r = 0.378,P < 0.001),waist circumference(r =0.356,P < 0.001),percent body fat(r = 0.296,P < 0.001),systolic blood pressure(r = 0.202,P < 0.001),total cholesterol(r = 0.134,P < 0.001),triglycerides(r = 0.292,P < 0.001),cystatin C(r = 0.069,P < 0.001) and uric acid(r = 0.142,P < 0.001).The QUICKI index revealed a negative correlation with BMI(r =-0.254,P < 0.001),waist circumference(r = 0-0.243,P < 0.001),percent body fat(r =-0.217,P < 0.001),systolic blood pressure(r =-0.132,P < 0.001),total cholesterol(r =-0.106,P < 0.001),triglycerides(r =-0.205,P < 0.001),cystatin C(r =-0.044,P < 0.001) and uric acid(r =-0.096,P < 0.001).For subjects identified with IR,the odds ratio of an accompanying diagnosis of chronic hepatitis B was 1.534(95% CI:1.158-2.031,HOMA index criteria) or 1.566(95% CI:1.124-2.182,QUICKI criteria) after adjustment for age,gender,BMI,and amount of alcohol consumption.CONCLUSION:Our study demonstrates that CVHB is associated with IR.CVHB may need to be monitored for occurrence of IR and diabetes mellitus.

Steatosis and insulin resistance in hepatitis C: A way out for the virus?

The hepatitis C virus (HCV) induces lipid accumulation in vitro and in vivo. The pathogenesis of steatosis is due to both viral and host factors. Viral steatosis is mostly reported in patients with genotype 3a, whereas meta-bolic steatosis is often associated with genotype 1 and metabolic syndrome. Several molecular mechanisms responsible for steatosis have been associated with the HCV core protein, which is able to induce gene expres-sion and activity of sterol regulatory element binding protein 1 (SREBP1) and peroxisome proliferator-activat-ed receptor γ (PPARγ), increasing the transcription of genes involved in hepatic fatty acid synthesis. Steatosis has been also implicated in viral replication. In infected cells, HCV core protein is targeted to lipid droplets which serve as intracellular storage organelles. These studies have shown that lipid droplets are essential for virus assembly. Thus, HCV promotes steatosis as an eff icient mechanism for stable viral replication. Chronic HCV in-fection can also induce insulin resistance. In patients with HCV, insulin resistance is more strongly associated with viral load than visceral obesity. HCV seems to lead to insulin resistance through interference of intracellular insulin signalling by HCV proteins, mainly, the serine phosphorylation of insulin receptor-1 (IRS-1) and im-pairment of the downstream Akt signalling pathway. The HCV core protein interferes with in vitro insulin signal-ling by genotype-specif ic mechanisms, where the role of suppressor of cytokine signal 7 (SOCS-7) in genotype 3aand mammalian target of rapamycin (mTOR) in geno-type 1 in IRS-1 downregulation play key roles. Steatosis and insulin resistance have been associated with f ibrosis progression and a reduced rate of sustained response to peginterferon plus ribavirin.

Clinical expression of insulin resistance in hepatitis C and B virus-related chronic hepatitis:Differences and similarities

AIM： To investigate the prevalence of the clinical pa- rameters of insulin resistance and diabetes in patients affected by chronic hepatitis C （CHC） or chronic hepa- titis B （CHB）. METHODS： We retrospectively evaluated 852 consec- utive patients （726 CHC and 126 CriB） who had under- gone liver biopsy. We recorded age, sex, ALT, type 2 diabetes and/or metabolic syndrome （MS）, body mass index （BMI）, and apparent disease duration （ADD）. RESULTS： Age, ADD, BMI, prevalence of MS and diabetes in patients with mild/moderate liver fibrosis were significantly higher in CHC. However, the degree of steatosis and liver fibrosis evaluated in liver biop- sies did not differ between CHC and CHB patients. At multivariate analysis, age, sex, BMI, ALT and diabetes were independent risk factors for liver fibrosis in CHC, whereas only age was related to liver fibrosis in CHB. We also evaluated the association between significant steatosis （〉 30%） and age, sex, BMI, diabetes, MS and liver fibrosis. Diabetes, BMI and liver fibrosis were associated with steatosis 〉 30% in CHC, whereas only age and BMI were related to steatosis in CriB. CONCLUSION： These data may indicate that hepatitis C virus infection is a risk factor for insulin resistance.

Interaction of IFNL3 with insulin resistance,steatosis and lipid metabolism in chronic hepatitis C virus infection

Metabolic changes are inextricably linked to chronic hepatitis C(CHC).Recently polymorphisms in the IFNL3(IL28B)region have been shown to be strongly associated with spontaneous and treatment induced recovery from hepatitis C virus(HCV)infection.Further,circumstantial evidence suggests a link between IFNL3single nucleotide polymorphisms and lipid metabolism,steatosis and insulin resistance in CHC.The emerging picture suggests that the responder genotypes of IFNL3polymorphisms are associated with a higher serum lipid profile,and less frequent steatosis and insulin resistance.This review analyzes the current data regarding this interaction and its meaning for HCV pathogenesis and disease progression.

Hippocampal insulin resistance and the Sirtuin 1 signaling pathway in diabetes-induced cognitive dysfunction

In the peripheral nervous system,the activation of Sirtuin 1 can improve insulin resistance;however,the role played by Sirtuin 1 in the central nervous system remains unknown.In this study,rat models of diabetes mellitus were generated by a single injection of streptozotocin.At 8 weeks after streptozotocin injection,the Morris water maze test and western blot assays confirmed that the diabetic model rats had learning and memory deficits,insulin resistance,and Sirtuin 1 expression could be detected in the hippocampus.Insulin and the insulin receptor inhibitor S961 were intranasally administered to investigate the regulatory effects of insulin signaling on Sirtuin 1.The results showed that insulin administration improved the impaired cognitive function of diabetic model rats and increased the expression levels of phosphorylated insulin receptor,phosphorylated insulin receptor substrate 1,and Sirtuin 1 in the hippocampus.Conversely,S961 administration resulted in more severe cognitive dysfunction and reduced the expression levels of phosphorylated insulin receptor,phosphorylated insulin receptor substrate 1,and Sirtuin 1.The Sirtuin 1 activator SRT2104 and the inhibitor Sirtinol were injected into the lateral ventricle,which revealed that the activation of Sirtuin 1 increased the expression levels of target of rapamycin complex 1,phosphorylated cAMP-response elementbinding protein,and brain-derived neurotrophic factor.Hippocampal dendritic length and spine density also increased in response to Sirtuin 1 activation.In contrast,Sirtinol decreased the expression levels of target of rapamycin complex 1,phosphorylated cAMP-response elementbinding protein,and brain-derived neurotrophic factor and damaged the dendritic structure.These findings suggest that the Sirtuin 1 signaling pathway plays an important role in the development of insulin resistance-related cognitive deficits in diabetic rats.This study was approved by the Animal Ethics Welfare Committee of the First Affiliated Hospital of Hunan University of Chinese Medicine(approval No.ZYFY201811207)in November 2018.

Exosomes Derived from Human Umbilical Cord Mesenchymal Stem Cells Enhance Insulin Sensitivity in Insulin Resistant Human Adipocytes

Insulin resistance is an essential characteristic of type 2 diabetes mellitus(T2DM),which can be induced by glucotoxicity and adipose chronic inflammation.Mesenchymal stem cells(MSCs)and their exosomes were reported to ameliorate T2DM and its complications by their immunoregulatory and healing abilities.Exosomes derived from MSCs contain abundant molecules to mediate crosstalk between cells and mimic biological function of MSCs.But the role of exosomes derived from human umbilical cord mesenchymal stem cells(hUC-MSCs)in insulin resistance of human adipocytes is unclear.In this study,exosomes were harvested from the conditioned medium of hUC-MSCs and added to insulin-resistant adipocytes.Insulin-stimulated glucose uptake was measured by glucose oxidase/peroxidase assay.The signal pathway involved in exosome-treated adipocytes was detected by RT-PCR and Western blotting.The biological characteristics and function were compared between hUC-MSCs and human adipose-derived mesenchymal stem cells(hAMSCs).The results showed that hAMSCs had better adipogenic ability than hUC-MSCs.After induction of mature adipocytes by adipogenesis of hAMSC,the model of insulin-resistant adipocytes was successfully established by TNF-αand high glucose intervention.After exosome treatment,the insulin-stimulated glucose uptake was significantly increased.In addition,the effect of exosomes could be stabilized for at least 48 h.Furthermore,the level of leptin was significantly decreased,and the mRNA expression of sirtuin-1 and insulin receptor substrate-1 was significantly upregulated after exosome treatment.In conclusion,exosomes significantly improve insulin sensitivity in insulin-resistant human adipocytes,and the mechanism involves the regulation of adipokines.

Wrist circumference: A new marker for insulin resistance in African women with polycystic ovary syndrome

BACKGROUND Insulin resistance(IR)is the main complication found in 35%-80%of women with polycystic ovary syndrome(PCOS).However,there is no definite consensus regarding which marker to use for its assessment in PCOS women.Research has shown that hyperinsulinemia is correlated with increased bone mass.Given that most women with PCOS are insulin resistant,which is independent from body fat and characterized by hyperinsulinemia,it could be hypothesized that there would be an increased bone mass in the patient as a result.Subsequently,increased bone mass could be measured using the wrist circumference method.AIM To assess the wrist circumference as an easy-to-detect marker of IR in Congolese women with PCOS.METHODS Seventy-two Congolese women with PCOS and seventy-one controls from the same ethnic group,were enrolled in the study(mean age 24.33±5.36 years).Fasting biochemical parameters,and the Homeostasis Model Assessment of insulin resistance(HOMA-IR)and body composition were evaluated.The nondominant wrist circumference was measured manually,as was the waist circumference(WC),hip circumference,height and weight.Calculated measures included evaluation of body mass index(BMI),Waist-to-Height(WHtR)and Waist-to-hip ratio(WHR).In addition,body composition was assessed by Bioelectrical Impedance Analysis using a body fat analyzer.RESULTS The non-dominant wrist circumference was more closely correlated with HOMAIR(r=0.346;P=0.003)and was the best anthropometrical marker correlated with IR(P=0.011)compared with other anthropometrical markers in women with PCOS:Dominant Wrist Circumference(r=0.315;P=0.007),Waist Circumference(WC)(r=0.259;P=0.028),BMI(r=0.285;P=0.016),WHR(r=0.216;P=0,068)and WHtR(r=0.263;P=0.027).The diagnostic accuracy of the non-dominant wrist circumference for the presence or absence of IR using Receiver-operating characteristic(ROC)curve analysis showed that the area under the ROC curve was 0.72.A cutoff value for the non-dominant wrist circumference of 16.3 cm was found to be the best predictor of IR in Congolese women with PCOS.CONCLUSION Non-dominant wrist circumference is,to date,the best anthropometrical marker of IR in Sub-Saharan African women with PCOS.It could be suggested as an easy-to-detect marker for assessing IR.

Iron overload and cofactors with special reference to alcohol,hepatitis C virus infection and steatosis/insulin resistance

There are several cofactors which affect body iron metabolism and accelerate iron overload. Alcohol and hepatic viral infections are the most typical examples for clarifying the role of cofactors in iron overload. In these conditions, iron is deposited in hepatocytes and Kupffer cells and reactive oxygen species （ROS） produced through Fenton reaction have key role to facilitate cellular uptake of transferrin-bound iron. Furthermore, hepcidin, antimicrobial peptide produced mainly in the liver is also responsible for intestinal iron absorption and reticuloendothelial iron release. In patients with ceruloplasmin deficiency, anemia and secondary iron overload in liver and neurodegeneration are reported. Furthermore, there is accumulating evidence that fatty acid accumulation without alcohol and obesity itself modifies iron overload states. Ineffective erythropoiesis is also an important factor to accelerate iron overload, which is associated with diseases such as thalassemia and myelodysplastic syndrome. When this condition persists, the dietary iron absorption is increased due to the increment of bone marrow erythropoiesis and tissue iron overload will thereafter occurs. In porphyria cutanea tarda, iron is secondarily accumulated in the liver.

Postprandial dyslipidemia in insulin resistant states in adolescent populations

Obesity and the metabolic syndrome are becoming increasingly prevalent not only in adults,but also in adolescents.The metabolic syndrome,a complex cluster of metabolic abnormalities,increases one’s risk of developing type 2 diabetes and cardiovascular disease(CVD).Dyslipidemia,a key component of the metabolic syndrome,is highly associated with insulin resistance and contributes to increased CVD risk.Dyslipidemia has traditionally been assessed using a fasting lipid profile [i.e.fasting triglycerides,total cholesterol,low-density lipoprotein cholesterol(LDL-C),and high-density lipoprotein cholesterol(HDL-C)].However,the postprandial state predominates over the course of a day and non-fasting triglycerides independently predict CVD risk.In insulin resistant states,the intestine overproduces triglyceride-rich lipoprotein(TRL) particles,termed chylomicrons(CMs),following ingestion of a fat-containing meal,as well as in the fasting state.Along with elevated hepatic TRLs(i.e.very-low density lipoproteins),CMs contribute to remnant lipoprotein accumulation,small dense LDL particles,and reduced HDL-C,which collectively increase CVD risk.Given the early genesis of atherosclerosis and physiological metabolic changes during adolescence,studying postprandial dyslipidemia in the adolescent population is an important area of study.Postprandial dyslipidemia in the pediatric population poses a significant public health concern,warranting a better understanding of its pathogenesis and association with insulin resistance and CVD.This review discusses the metabolic syndrome,focusing on the link between insulin resistance,postprandial dyslipidemia,and CVD risk.Furthermore,the clinical significance and functional assessment of postprandial dyslipidemia,specifically in the adolescent population,is discussed in more detail.