Insulin resistance: cellular and clinical concepts

Unraveling the mechanisms of hepatogenous diabetes and its therapeutic perspectives

The review focused mainly on the pathogenesis of hepatogenous diabetes (HD) in liver cirrhosis (LC). This review reveals parallels between the mechanisms of metabolic dysfunction observed in LC and type II diabetes (T2DM), suggesting a shared pathway leading to HD. It underscores the role of insulin in HD pathogenesis, highlighting key factors such as insulin signaling, glucose metabolism, insulin resistance (IR), and the influence of adipocytes. Furthermore, the impact of adipose tissue accumulation, fatty acid metabolism, and pro-inflammatory cytokines like Tumor necrosis factor-α (TNF-α) on IR are discussed in the context of HD. Altered signaling pathways, disruptions in the endocrine system, liver inflammation, changes in muscle mass and composition, and modifications to the gut microbiota collectively contribute to the complex interplay linking cirrhosis and HD. This study highlights how important it is to identify and treat this complex condition in cirrhotic patients by thoroughly analyzing the link between cirrhosis, IR, and HD. It also emphasizes the vitality of targeted interventions. Cellular and molecular investigations into IR have revealed potential therapeutic targets for managing and preventing HD.

Molecular targets for management of diabetes: Remodelling of white adipose to brown adipose tissue

Diabetes mellitus is a disorder characterised metabolic dysfunction that results in elevated glucose level in the bloodstream. Diabetes is of two types, type1 and type 2 diabetes. Obesity is considered as one of the major reasons intended for incidence of diabetes hence it turns out to be essential to study about the adipose tissue which is responsible for fat storage in body. Adipose tissues play significant role in maintaining the balance between energy stabilization and homeostasis. The three forms of adipose tissue are - White adipose tissue (WAT), Brown adipose tissue (BAT) and Beige adipose tissue (intermediate form). The amount of BAT gets reduced, and WAT starts to increase with the age. WAT when exposed to certain stimuli gets converted to BAT by the help of certain transcriptional regulators. The browning of WAT has been a matter of study to treat the metabolic disorders and to initiate the expenditure of energy. The three main regulators responsible for the browning of WAT are PRDM16, PPARγ and PGC-1α via various cellular and molecular mechanism. Presented review article includes the detailed elaborative aspect of genes and proteins involved in conversion of WAT to BAT.

The underlying causes, treatment options of gut microbiota and food habits in type 2 diabetes mellitus: a narrative review

Type 2 diabetes mellitus is a long-lasting endocrine disorder characterized by persistent hyperglycaemia, which is often triggered by an entire or relative inadequacy of insulin production or insulin resistance. As a result of resistance to insulin (IR) and an overall lack of insulin in the body, type 2 diabetes mellitus (T2DM) is a metabolic illness that is characterized by hyperglycaemia. Notably, the occurrence of vascular complications of diabetes and the advancement of IR in T2DM are accompanied by dysbiosis of the gut microbiota. Due to the difficulties in managing the disease and the dangers of multiple accompanying complications, diabetes is a chronic, progressive immune-mediated condition that plays a significant clinical and health burden on patients. The frequency and incidence of diabetes among young people have been rising worldwide. The relationship between the gut microbiota composition and the physio-pathological characteristics of T2DM proposes a novel way to monitor the condition and enhance the effectiveness of therapies. Our knowledge of the microbiota of the gut and how it affects health and illness has changed over the last 20 years. Species of the genus Eubacterium, which make up a significant portion of the core animal gut microbiome, are some of the recently discovered 'generation' of possibly helpful bacteria. In this article, we have focused on pathogenesis and therapeutic approaches towards T2DM, with a special reference to gut bacteria from ancient times to the present day.

Interesterified palm oil promotes insulin resistance and altered insulin secretion and signaling in Swiss mice

Interesterified fats have been used to replace trans-fat in ultra-processed foods. However, their metabolic effects are not completely understood. Hence, this study aimed to investigate the effects related to glucose homeostasis in response to interesterified palm oil or refined palm oil intake. Four-week-old male Swiss mice were randomly divided into four experimental groups and fed the following diets for 8 weeks: a normocaloric and normolipidic diet containing refined palm oil (PO group) or interesterified palm oil (IPO group); a hypercaloric and high-fat diet containing refined PO (POHF group) or interesterified PO (IPOHF group). Metabolic parameters related to body mass, adiposity and food consumption showed no significant differences. As for glucose homeostasis parameters, interesterified palm oil diets (IPO and IPOHF) resulted in higher glucose intolerance than unmodified palm oil diets (PO and POHF). Euglycemic-hyperinsulinemic clamp assessment showed a higher endogenous glucose production in the IPO group compared with the PO group. Moreover, the IPO group showed significantly lower p-AKT protein content (in the muscle and liver tissues) when compared with the PO group. Analysis of glucose-stimulated static insulin secretion (11.1 mmol/L glucose) in isolated pancreatic islets showed a higher insulin secretion in animals fed interesterified fat diets (IPO and IPOHF) than in those fed with palm oil (PO and POHF). Interesterified palm oil, including in normolipidic diets, can impair insulin signaling in peripheral tissues and increase insulin secretion by β-cells, characterizing insulin resistance in mice.

An Insight of Naturally Occurring Phytoconstituents and Novel Approaches Towards the Treatment of Diabetes

BACKGROUND

The rising in diabetes incidents has clearly become one main worldwide health problem. Individuals suffering from diabetes are still more susceptible to many long-term and short-term side effects, which most often cause fatalities. Even though chemically synthesized anti-diabetic entities are capable of helping manage and treat, there has been significant risks related with their prolong and repetitive use. Hence, there is a requirement for safer and novel approaches that might be formed and utilized.

OBJECTIVE

Aim of the present review is to explain the naturally occurring phytochemicals and novel approach as anti-diabetic agents in the treatment of diabetes and its related issues.

METHOD

A survey of Google scholar, Research Gate, Pubmed, Science Direct, NCBI database was carried out conducted to determine a most hopeful phytochemicals and novel drug delivery systems in the management of diabetes.

RESULT

The study stressed the significance of phytomolecules and some novel approaches researched or reported in the literature for the management and cure of diabetes. It is suggested that changes in lifestyle can help patients and like nutritional support, assessment and lifestyle guidance must be individualized based on physical and functional capacity. Further evaluations and improved preventative medicine were the result of improving patient outcomes.

CONCLUSION

Conventional or synthetic drugs provide relief for short time but nanoformulations of phytomolecules offer an improved therapeutic with fewer negative side effects. Herbal medicines are rich in phytoconstituents and possess variety of health benefits. This review is compilation of phytoconstituents and novel drug delivery system of phytomolecules i.e. nanoparticles, niosomes, microsphere, microparticle and others.

Association between the triglyceride-glucose index and suicidal ideation: A nationwide cross-sectional survey

PURPOSE

This study investigated the relationship between insulin resistance and suicidal ideation.

METHODS

We analyzed the data of 21,350 participants from 4 years of the Korea National Health and Nutrition Examination Survey. The triglyceride-glucose (TyG) index was used to assess insulin resistance, and suicidal ideation was recorded through self-reported questionnaires. We used multivariable logistic regression analysis to ensure the independent association between the TyG index and suicidal ideation.

RESULTS

Approximately 4.3 % of participants had suicidal ideation. The TyG index was significantly associated with suicidal ideation, but only among women. Subgroup analysis in women revealed that the association between the TyG index and suicidal ideation was more remarkable in the low-risk group for suicide.

LIMITATIONS

Causality and the impact of unmeasured confounders were not addressed.

CONCLUSION

The TyG index may help prevent suicide in women via earlier detection of suicidal ideation.

Barriers to Exercise in Adults With Type 1 Diabetes and Insulin Resistance

OBJECTIVE

Our aim in this study was to assess attitudes toward exercise and quality of life (QoL) in adults with type 1 diabetes (T1D) with and without insulin resistance (IR).

METHODS

We pooled baseline pretreatment data from a subset of individuals with T1D from 2 randomized controlled trials. Estimated glucose disposal rate (eGDR), a validated surrogate marker of IR, was calculated using an established formula to classify individuals according to IR status with a cutpoint of <6 mg/kg/min for the determination of IR. Self-reported barriers to exercise were obtained using a validated questionnaire, the Barriers to Physical Activity in T1D (BAPAD-1). In addition, QoL was determined using the 36-item Short Form (SF-36) questionnaire. Differences between dichotomized variables were assessed using the independent t test, Mann-Whitney U test, or Fisher exact test. Linear regression was employed to explore the association of eGDR with BAPAD-1 and QoL scores, with sequential adjustment for potential confounders.

RESULTS

Of the 85 individuals included in our study, 39 were classified as having IR. The mean BAPAD-1 total score was higher for individuals with IR (IR: 3.87±0.61; non-IR: 2.83±0.55; p<0.001). The highest exercise barrier scores for individuals with IR were risk of hypoglycemia (5.67±1.26) and risk of hyperglycemia (5.23±1.20), whereas the highest scoring exercise barrier scores for non-IR individuals were not diabetes-related, with low level of fitness (3.91±1.26) and physical health status, excluding diabetes (3.67±1.48), ranked highest. QoL scores were comparable between groups (p>0.05).

CONCLUSIONS

Risk of hypoglycemia was the greatest barrier to exercise in individuals with T1D with IR, whereas non-diabetes-related barriers to exercise were more salient in individuals with T1D without IR.

Metagenomic Shotgun Sequencing Reveals Specific Human Gut Microbiota Associated with Insulin Resistance and Body Fat Distribution in Saudi Women

(1) Background: Gut microbiota dysbiosis may lead to diseases such as insulin resistance and obesity. We aimed to investigate the relationship between insulin resistance, body fat distribution, and gut microbiota composition. (2) Methods: The present study included 92 Saudi women (18–25 years) with obesity (body mass index (BMI) ≥ 30 kg/m2, n = 44) and with normal weight (BMI 18.50–24.99 kg/m2, n = 48). Body composition indices, biochemical data, and stool samples were collected. The whole-genome shotgun sequencing technique was used to analyze the gut microbiota. Participants were divided into subgroups stratified by the homeostatic model assessment for insulin resistance (HOMA-IR) and other adiposity indices. (3) Results: HOMA-IR was inversely correlated with Actinobacteria (r = −0.31, p = 0.003), fasting blood glucose was inversely correlated with Bifidobacterium kashiwanohense (r = −0.22, p = 0.03), and insulin was inversely correlated with Bifidobacterium adolescentis (r = −0.22, p = 0.04). There were significant differences in α- and β-diversities in those with high HOMA-IR and waist–hip ratio (WHR) compared to low HOMA-IR and WHR (p = 0.02, 0.03, respectively). (4) Conclusions: Our findings highlight the relationship between specific gut microbiota at different taxonomic levels and measures of glycemic control in Saudi Arabian women. Future studies are required to determine the role of the identified strains in the development of insulin resistance.

Young adult male LEW.1WR1 rats have reduced beta cell area and develop glucose intolerance

Prediabetes affects 1 in 3 American adults and is characterized by insulin resistance, insulin hypersecretion, and impaired glucose tolerance. Weanling LEW.1WR1 (1WR1) rats have increased blood insulin concentrations, so we hypothesized that young adult 1WR1 rats would develop impaired glucose tolerance due to the poor regulation of insulin. We monitored glucose tolerance, insulin tolerance, and weight gain for 10 weeks to assess if there was a decline in glucose processing over time. 1WR1 rats were significantly more glucose intolerant after 8 weeks. 1WR1 rats had increased body mass, yet abdominal fat mass was not significantly increased. Although the 1WR1 rats had increased circulating insulin and glucagon protein levels, 1WR1 rat beta cell area was significantly reduced. There may be underlying insulin resistance as evidenced by dysfunctional insulin regulation during fasting. Understanding the metabolic phenotype of this rat model can provide insight into the human pathophysiological changes that increase susceptibility to glucose intolerance and prediabetes.

Cannabinoids Transmogrify Cancer Metabolic Phenotype via Epigenetic Reprogramming and a Novel CBD Biased G Protein-Coupled Receptor Signaling Platform

The concept of epigenetic reprogramming predicts long-term functional health effects. This reprogramming can be activated by exogenous or endogenous insults, leading to altered healthy and different disease states. The exogenous or endogenous changes that involve developing a roadmap of epigenetic networking, such as drug components on epigenetic imprinting and restoring epigenome patterns laid down during embryonic development, are paramount to establishing youthful cell type and health. This epigenetic landscape is considered one of the hallmarks of cancer. The initiation and progression of cancer are considered to involve epigenetic abnormalities and genetic alterations. Cancer epigenetics have shown extensive reprogramming of every component of the epigenetic machinery in cancer development, including DNA methylation, histone modifications, nucleosome positioning, non-coding RNAs, and microRNA expression. Endocannabinoids are natural lipid molecules whose levels are regulated by specific biosynthetic and degradative enzymes. They bind to and activate two primary cannabinoid receptors, type 1 (CB1) and type 2 (CB2), and together with their metabolizing enzymes, form the endocannabinoid system. This review focuses on the role of cannabinoid receptors CB1 and CB2 signaling in activating numerous receptor tyrosine kinases and Toll-like receptors in the induction of epigenetic landscape alterations in cancer cells, which might transmogrify cancer metabolism and epigenetic reprogramming to a metastatic phenotype. Strategies applied from conception could represent an innovative epigenetic target for preventing and treating human cancer. Here, we describe novel cannabinoid-biased G protein-coupled receptor signaling platforms (GPCR), highlighting putative future perspectives in this field.

Application of Nanoparticles: Diagnosis, Therapeutics, and Delivery of Insulin/Anti-Diabetic Drugs to Enhance the Therapeutic Efficacy of Diabetes Mellitus

Diabetes mellitus (DM) is a chronic metabolic disorder of carbohydrates, lipids, and proteins due to a deficiency of insulin secretion or failure to respond to insulin secreted from pancreatic cells, which leads to high blood glucose levels. DM is one of the top four noncommunicable diseases and causes of death worldwide. Even though great achievements were made in the management and treatment of DM, there are still certain limitations, mainly related to the early diagnosis, and lack of appropriate delivery of insulin and other anti-diabetic agents. Nanotechnology is an emerging field in the area of nanomedicine and NP based anti-diabetic agent delivery is reported to enhance efficacy by increasing bioavailability and target site accumulation. Moreover, theranostic NPs can be used as diagnostic tools for the early detection and prevention of diseases owing to their unique biological, physiochemical, and magnetic properties. NPs have been synthesized from a variety of organic and inorganic materials including polysaccharides, dendrimers, proteins, lipids, DNA, carbon nanotubes, quantum dots, and mesoporous materials within the nanoscale size. This review focuses on the role of NPs, derived from organic and inorganic materials, in the diagnosis and treatment of DM.

Associations between maternal adiposity and appetite-regulating hormones in human milk are mediated through maternal circulating concentrations and might affect infant outcomes

Background

Appetite-regulating hormones (ARH) in human milk (HM) are suggested to affect infants’ milk intake and possibly infant growth. Maternal adiposity might contribute to higher levels of ARH in HM, either from the mammary gland or from raised circulating levels due to higher adiposity. Counterfactual-based mediation analysis can define indirect and direct effects between HM ARH and maternal and infant factors, and might be an important tool when investigating the mother-milk-infant triad.

Objective

We aim to investigate whether potential associations between (1) maternal adiposity and HM ARH and (2) HM ARH and infant milk intake and growth are mediated through maternal and infant plasma ARH, respectively.

Materials and methods

Maternal and infant anthropometry and body composition, HM and blood samples were collected from 223 mother-infant dyads participating in the Mother, Infant and Lactation Quality study at three postpartum visits from 1 to 8.49 months. Leptin, insulin and adiponectin were analyzed using immunoassays. Mediation analyses using linear mixed-effect models were applied to investigate the direct and indirect effects through maternal and infant plasma hormone concentrations.

Results

A positive association between maternal body-mass-index (BMI) and HM leptin was mediated by maternal plasma leptin by 29% when fixing BMI to < 25 kg/m², and through 51% when fixing BMI to ≥ 25 kg/m² (p_interaction < 0.01). There was no mediated effect through plasma insulin in the association between BMI and HM insulin (p = 0.068). We found negative and positive associations between HM insulin and total milk intake and infant weight, respectively, however, these diminished in mediation analyses with reduced sample sizes.

Conclusion

Our main results suggest that the association between maternal adiposity and HM leptin was mediated through circulating leptin to a stronger degree for mothers with overweight compared to mothers with normal-weight. This indicates that excess maternal adiposity, and the resulting rise of circulating leptin and possible concomitant low-grade inflammation, may be reflected in HM composition.

Clinical trials registry number

NCT03254329.

Effect of Psyllium husk fiber and lifestyle modification on human body insulin resistance

Insulin resistance is a metabolic disorder that is increasing worldwide and is associated with some of the most common diseases affecting modern societies including diabetes, hypertension, obesity, and coronary heart disease. Changes in diet and physical activity have a profound effect on lowering the risk and cost of managing insulin resistance compared to the pharmacological approach. An interventional study of 16 weeks explored the effect of Psyllium husk fiber in combination with lifestyle modification on insulin resistance among the centrally obese school teachers of district Malakand Khyber Pakhtunkhwa. One Hundred twenty school teachers with central obesity, aged 40-60 years, with no chronic disease history were divided into four subgroups (n = 30) with equal gender bifurcation; a control group, lifestyle modification (LSM) group, psyllium husk fiber (PSH) group, and the combined intervention of LSM & PSH group. Fasting serum was collected to analyze fasting blood glucose, and insulin resistance by using the HOMA-IR method at baseline and post-intervention. A significant effect of the intervention was observed on fasting blood glucose. The combined group of LSM&PSH showed the highest mean change of -7.5 ± 2.6 mg/dl (-9%), followed by the PSH group with a mean change of -6.3 ± 2.1 mg/dl, (-7%). Likewise a significant effect (P < 0.05) on HOMA-IR was observed in the combined group of LSM&PSH with a mean of 1.02 ± 0.14 molar units (-58%), followed by the PSH group with a mean of 1.55 ± 0.14 molar units (-33%). The current study was carried out to assess the effect of regular consumption of Psyllium husk fiber in combination with lifestyle modification on insulin resistance and fasting blood glucose.

Vitamin D3 intake as modulator for the early biomarkers of myocardial tissue injury in diabetic hyperlipidaemic rats

CONTEXT

Myocardial cell death occurs within hours following the onset of myocardial ischaemia and its chief cause is atherosclerosis. There is a link between vitamin D3 deficiency and many cardiovascular risk factors.

OBJECTIVE

This study compared the effect of vitamin D3 on early biomarkers of myocardial injury, to that of atorvastatin.

METHODS

Diabetic hyperlipidaemia was induced in Wistar rats, which were divided into 3 groups: diabetic hyperlipidaemic control, diabetic hyperlipidaemic rats treated with atorvastatin and diabetic hyperlipidaemic rats treated with vitamin D3. Blood glucose, glycated haemoglobin and lipid profile were evaluated. Markers of myocardial injury were examined including cardiac troponin, heart fatty acid binding protein (HFABP) and C-terminal pro-endothelin-1 (CT-pro-ET-1).

RESULTS

Vitamin D3 and atorvastatin intake improved lipid profile and glucose homeostasis, and reduced levels of predictive biomarkers of myocardial injury.

CONCLUSION

Vitamin D3 can be used in a suitable dose as a safe and protective candidate against myocardial injury.

Experimental model of unpredictable maternal stress and diabetes risk of offspring: An immunohistochemical study

The effect of stress on the occurrence of diabetes mellitus (DM) is commonly reported in recent studies. Maternal stress may have a negative effect on the later life of offspring. However, most studies only investigated long-term intrauterine stress on behavioral, emotional, psychological, and immunological disorders of offspring. The relationship between maternal stress and DM occurrence in the later life period of offspring is not known. This rat model study aimed to evaluate the susceptibility of offspring to DM after exposure to intrauterine stress. The purpose of this study is to examine serum glucose levels of mothers and offspring exposed to maternal stress and to evaluate pancreatic tissues pathologically and immunohistochemically. Twelve, Wistar Albino female rats were equally divided into two groups: controls and maternal stress groups. Normal routine conditions were applied to the control group without any stress. The pregnant rats in the maternal stress group were exposed to chronic unpredictable stressors throughout the 21-day gestation. One female and one male offspring and mothers from each term delivery were randomly selected and euthanatized at the 35th day. During the necropsy, blood and pancreatic tissue samples were collected from both mothers and pups. High serum glucose levels from mothers and offspring in the maternal stress group and the control group were compared. Additionally, histopathological examinations assessed the increased cell degeneration in mother rats and offspring. Immunohistochemical examinations revealed decreased insulin, amylin, and insulin receptor expressions and slightly increased glucagon expression in Langerhans islet cells in the maternal stress group. These results indicated that maternal stress may be a predisposing factor for DM in both mothers and offspring in their later life periods.

Non-Pharmacological Treatments for Insulin Resistance: Effective Intervention of Plant-Based Diets—A Critical Review

Plant-based diets are becoming increasingly popular. Vegetarian diets are better for the environment and exhibit health benefits. A correctly balanced plant-based diet is appropriate at every stage of life. Compared to omnivores, vegetarians consume more fruits and vegetables, more fibre, vitamins C and E, magnesium and less saturated fats. In general, they have better nutrition knowledge, and they are slimmer, healthier and live longer than omnivores. It also seems that following a plant-based diet prevents the onset of chronic diseases such as cardiovascular diseases, hypertension, type 2 diabetes, obesity and some cancers. Food intake has a key influence on insulin resistance. Consumption of calorie-rich and highly processed foods, meats and sweetened beverages is a characteristic element of Western diets. They promote and elevate insulin resistance and type 2 diabetes. In contrast, intake of pulses and exclusion of meats as well as animal products bring significant benefits to vegetarian diets. According to studies, vegetarians and vegans have better blood parameters, including better glucose, insulin, total cholesterol, and LDL cholesterol levels. Their homeostatic model assessment for insulin resistance (HOMA-IR) test results are also better. More plant-based foods and fewer animal foods in a diet result in lower insulin resistance and a lower risk of prediabetes and type 2 diabetes. The aim of the study was to investigate the effect of plant-based diets on insulin resistance. In this review, we focused on presenting the positive effects of vegetarian and vegan diets on insulin resistance while showing possible clinical applications of plant-based diets in the treatment and prevention of modern-age diseases. Current and reliable publications meeting the requirements of Evidence-Based Medicine (EBM) were taken into account in this review.

Pathophysiological aspects of insulin resistance in Atrial Fibrillation: novel therapeutic approaches

Background

Insulin resistance is associated with metabolic disorders including diabetes, obesity, hypertension, and inflammation which are the risk factors for Atrial Fibrillation. Many studies have reported that type 2 diabetes and AF are related and also their prevalence is increasing globally. Moreover, insulin resistance begins the type 2 diabetes.

Main body

This review explains the pathophysiological aspects of insulin resistance in AF patients and discusses the drugs that are used to manage insulin resistance including Biguanides (metformin), thiazolidinediones (TZDs) [Pioglitazone, rosiglitazone], Sodium-glucose cotransporter 2 (SGLT2) inhibitors, Concentrated Insulin Products, Dipeptidyl peptidase-4 (DPP-4) Inhibitors, Glucagon-like peptide 1 (GLP-1) receptor Agonists, Pramlintide, Sulfonylureas, Meglitinides, α-Glucosidase Inhibitors, Colesevelam, Bromocriptine. This review will highlight a few major drugs that played a significant role in AF patients. For this purpose, many databases were used for reviewing the literature and keywords are used such as Insulin Resistance, Pathophysiology, Atrial Fibrillation, and Drugs.

Conclusion

This review article concludes that insulin resistance is related to AF. It also provides an outlook on the recent pathophysiological aspects of insulin resistance in AF; however, more studies are needed to clarify the management of insulin resistance in AF patients to prevent the development of type 2 diabetes.

Prognostic impact of body mass index (BMI) in HER2+ breast cancer treated with anti-HER2 therapies: from preclinical rationale to clinical implications

Human Epidermal growth factor Receptor 2 (HER2) overexpression or HER2 gene amplification defines a subset of breast cancers (BCs) characterized by higher biological and clinical aggressiveness. The introduction of anti-HER2 drugs has remarkably improved clinical outcomes in patients with both early-stage and advanced HER2+ BC. However, some HER2+ BC patients still have unfavorable outcomes despite optimal anti-HER2 therapies. Retrospective clinical analyses indicate that overweight and obesity can negatively affect the prognosis of patients with early-stage HER2+ BC. This association could be mediated by the interplay between overweight/obesity, alterations in systemic glucose and lipid metabolism, increased systemic inflammatory status, and the stimulation of proliferation pathways resulting in the stimulation of HER2+ BC cell growth and resistance to anti-HER2 therapies. By contrast, in the context of advanced disease, a few high-quality studies, which were included in a meta-analysis, showed an association between high body mass index (BMI) and better clinical outcomes, possibly reflecting the negative prognostic role of malnourishment and cachexia in this setting. Of note, overweight and obesity are modifiable factors. Therefore, uncovering their prognostic role in patients with early-stage or advanced HER2+ BC could have clinical relevance in terms of defining subsets of patients requiring more or less aggressive pharmacological treatments, as well as of designing clinical trials to investigate the therapeutic impact of lifestyle interventions aimed at modifying body weight and composition. In this review, we summarize and discuss the available preclinical evidence supporting the role of adiposity in modulating HER2+ BC aggressiveness and resistance to therapies, as well as clinical studies reporting on the prognostic role of BMI in patients with early-stage or advanced HER2+ BC.

Peripheral versus central insulin and leptin resistance: Role in metabolic disorders, cognition, and neuropsychiatric diseases

Insulin and leptin are classically regarded as peptide hormones that play key roles in metabolism. In actuality, they serve several functions in both the periphery and central nervous system (CNS). Likewise, insulin and leptin resistance can occur both peripherally and centrally. Metabolic disorders such as diabetes and obesity share several key features including insulin and leptin resistance. While the peripheral effects of these disorders are well-known (i.e. cardiovascular disease, hypertension, stroke, dyslipidemia, etc.), the CNS complications of leptin and insulin resistance have come into sharper focus. Both preclinical and clinical findings have indicated that insulin and leptin resistance are associated with cognitive deficits and neuropsychiatric diseases such as depression. Importantly, these studies also suggest that these deficits in neuroplasticity can be reversed by restoration of insulin and leptin sensitivity. In view of these observations, this review will describe, in detail, the peripheral and central functions of insulin and leptin and explain the role of insulin and leptin resistance in various metabolic disorders, cognition, and neuropsychiatric diseases.

Adipose Tissue Dysfunction: Impact on Bone and Osseointegration

Bone metabolism may be adversely affected in metabolic diseases such as obesity and metabolic syndrome, which are characterised by weight gain, due to the expansion of adipose tissue deposits. As an important regulator of energy metabolism, adipose tissues synthesise and secrete several key regulatory adipokines that influence a range of metabolic functions. This narrative review outlines the evidence for the mechanisms by which adipose tissue dysfunction may alter bone metabolism prior to the development of frank hyperglycaemia and presents the emerging evidence for the impact of diet-induced expansion of adipose tissue on implant osseointegration. Successful osseointegration requires normal bone cell function, and the expansion of adipose tissue deposits results in dysregulated adipokine production favouring an increase in pro-inflammatory adipokines, contributing to the development of a chronic inflammatory state and insulin resistance. The increase in inflammatory cytokines promotes the growth and differentiation of osteoclasts indirectly through the modulation of osteoblastic RANKL production and directly by reducing osteoclast apoptosis and increased osteoclastic expression of RANK. Conversely, the suppression of osteoblastic regulatory genes results in reduced osteoblast numbers and function contributing to compromised bone turnover. Compromised osseointegration has been established in hyperglycaemia; however, as discussed in this review, it may not be the only driver of altered bone metabolism. The incidence of metabolic disease in the community is rising, patients may present for implant treatment with undiagnosed, underlying changes to bone cell metabolism due to adipose tissue dysmetabolism.

Association Between Smoking Behavior and Insulin Resistance Using Triglyceride-Glucose Index Among South Korean Adults

CONTEXT

Insulin resistance is a determinant of diabetes. With the increasing popularity of electronic smoking, the number of dual smokers (smoking both cigarettes and electronic cigarettes [e-cigarettes]) is increasing. However, few studies have assessed the association between insulin resistance and smoking behavior, including dual smoking.

OBJECTIVE

This work aims to investigate the association between smoking behaviors and insulin resistance.

METHODS

This prospective, cross-sectional study took place among the general community. A total of 11 653 participants (4721 male and 6932 female) aged 19 years or older from the 2016 to 2018 Korea National Health and Nutrition Examination Survey were divided based on their smoking behaviors: dual smokers (both cigarettes and e-cigarettes), single smokers (cigarette smokers), previous smokers, and nonsmokers. Insulin resistance was determined based on the triglyceride-glucose index. Multiple logistic regression analysis was performed to investigate the association between smoking behavior and insulin resistance.

RESULTS

Among the participants, 205 males (3.9%) and 40 females (0.5%) were dual smokers, and 1581 males (29.9%) and 350 females (4.5%) were single smokers. Male and female smokers (dual and single) both had higher odds of being in a group with higher insulin resistance than nonsmokers (male, dual: OR = 2.19; 95% CI, 1.39-3.44; single: OR = 1.78; 95% CI, 1.43-2.22; female, dual: OR = 2.32; 95% CI, 1.01-5.34; single: OR = 1.76; 95% CI, 1.28-2.42).

CONCLUSION

This study suggests that single and dual smoking both may increase the risk of insulin resistance in the general population. Education on the adverse effects of smoking behaviors may be an important strategy to improve the health of the population.

Influence of Liver Cirrhosis on Blood Glucose, Insulin Sensitivity and Islet Function in Mice

BACKGROUND

The relationship between cirrhosis and diabetes is controversial. We studied the influence of cirrhosis on glucose levels and islet function and explored its possible mechanisms.

MATERIALS AND METHODS

Cirrhosis was induced in male C57BL/6 mice by bile duct ligation (BDL). Serum biochemical parameters were determined, and oral glucose tolerance tests (OGTT) were performed at 4 and 8 weeks after BDL. Histopathology and phospho-NF-κB-p65/I-kappa B α immunohistochemical staining of the liver and islet were observed. The protein levels of the insulin signaling system and the gene expression of insulin-degrading enzyme (IDE) in the liver and muscle were determined. The activity of glucokinase (GCK) and glucose 6-phosphatase (G6P) and glycogen levels in liver homogenates were measured.

RESULTS

After BDL, the mice developed cirrhosis, and fasting glucose decreased significantly, but 2 h postprandial glucose increased, and the insulin areas under the curves increased. At 4 weeks of BDL, the ratios of phospho-NF-κB-p65/I-kappa B α accumulation in the liver and islet increased, the activity of G6P and the glycogen content in liver homogenates decreased, the insulin signaling system and the gene expression of IDE in the liver was downregulated, and the islet areas were decreased. After 8 weeks, these changes were more severe.

CONCLUSIONS

In different periods of cirrhosis, the levels of fasting glucose and 2 h postprandial glucose changed in different amplitudes. Glycogen concentrations and the activity of G6P in the liver were decreased. The mice developed insulin resistance and the islet areas were decreased. The NF-κB pathway may play a role in the process.

Intranasal insulin and orexins to treat age-related cognitive decline

The intranasal (IN) administration of neuropeptides, such as insulin and orexins, has been suggested as a treatment strategy for age-related cognitive decline (ARCD). Because dysfunctional neuropeptide signaling is an observed characteristic of ARCD, it has been suggested that IN delivery of insulin and/or orexins may restore endogenous peptide signaling and thereby preserve cognition. IN administration is particularly alluring as it is a relatively non-invasive method that directly targets peptides to the brain. Several laboratories have examined the behavioral effects of IN insulin in young, aged, and cognitively impaired rodents and humans. These studies demonstrated improved performance on various cognitive tasks following IN insulin administration. Fewer laboratories have assessed the effects of IN orexins; however, this peptide also holds promise as an effective treatment for ARCD through the activation of the cholinergic system and/or the reduction of neuroinflammation. Here, we provide a brief overview of the advantages of IN administration and the delivery pathway, then summarize the current literature on IN insulin and orexins. Additional preclinical studies will be useful to ultimately uncover the mechanisms underlying the pro-cognitive effects of IN insulin and orexins, whereas future clinical studies will aid in the determination of the most efficacious dose and dosing paradigm. Eventually, IN insulin and/or orexin administration may be a widely used treatment strategy in the clinic for ARCD.

The effect of oral glucose tolerance testing on changes in arterial stiffness and blood pressure in elderly women with hypertension and relationships between the stage of diabetes and physical fitness levels

[Purpose]

The purpose of this study was to assess changes in blood glucose level, blood pressure, and arterial stiffness after a 75 g oral glucose tolerance test (OGTT) in elderly women aged over 65 years with hypertension and either normal glycemic control, impaired fasting glucose tolerance, or diabetes mellitus. We also wished to investigate the relationship between stages of diabetes and physical fitness.

[Methods]

A total of 24 elderly women with hypertension were assigned to a control group (CON; n=7), impaired fasting glucose group (IFG; n=9), and diabetes mellitus group (DM; n=8). In each group, blood glucose level, brachial ankle pulse wave velocity (PWV), and blood pressure were measured at baseline as well as 60 and 120 minutes after a 75 g OGTT. Physical fitness factors such as hand grip strength, balance test, 4 m gait speed test, chair stand test, short physical performance battery, and 6-minute walking test were subsequently assessed.

[Results]

In all three groups, blood glucose levels were significantly increased at 60 and 120 minutes after a 75 g OGTT. In the DM group, blood glucose levels were significantly higher before and after a 75 g OGTT than in the CON group. In the CON group, PWV was significantly increased at 60 minutes after a 75 g OGTT; however, there were no changes in other groups after glucose ingestion. In the CON group, systolic and diastolic blood pressures were significantly decreased at 60 and 120 minutes after a 75 g OGTT compared to baseline. However, there was no change in blood pressure after ingestion in the DM group. The IFG group had greater grip strength than the CON group; however, there were no differences in other variables between the groups.

[Conclusion]

After a 75 g OGTT, elderly women with hypertension and diabetes maintain higher blood glucose levels compared to those with hypertension alone. Unlike elderly women with hypertension alone, those with hypertension and diabetes did not show changes in arterial stiffness and blood pressure after a 75 g OGTT. Therefore, elderly women with hypertension and diabetes may not be able to control their blood vessels following a 75 g OGTT due to impaired vascular endothelial function. Moreover, there was no association between diabetes stage and physical fitness in elderly women with hypertension.

Triglyceride Induced Metabolic Inflammation: Potential Connection of Insulin Resistance and Recurrent Pregnancy Loss

The underlying correlative mechanisms between Insulin resistance (IR) and recurrent pregnancy loss (RPL) in patients without polycystic ovarian syndrome (PCOS) remain inconclusive. To investigate the association between triglyceride (TG) levels, lymphocyte subsets, and IR in RPL patients without PCOS and obesity. Eighty-nine subjects with an unexplained RPL, independent of PCOS/obesity were enrolled in this study. A 75-g oral glucose tolerance test was performed on each subject with plasma tested for glucose and insulin. The fasting venous blood of all subjects was collected for routine clinical chemistry analysis. Lymphocyte subsets were analyzed by four-color flow cytometry. As a result, TG levels were significantly elevated in RPL patients with IR compared to those without IR. Pearson linear correlation model and receiver operating characteristic (ROC) curve analyses revealed a significant positive association between TG and HOMA-IR index value. In multiple logistic regression analysis, TG was significantly associated with the risk of hyperinsulinemia and increased CD3⁺CD4⁺/CD3⁺CD8⁺ ratio which was significantly negatively correlated with disposition index (DI30) and DI120, indicators for insulin sensitivity. In addition, DI30 and DI120 were significantly decreased in the higher CD3⁺CD4⁺/CD3⁺CD8⁺ group. Our findings showed that the elevated TG and altered immune responses in RPL patients with IR are independent of PCOS and obesity, and could be used as an indicator of IR in RPL patients. These results contribute to the understanding of the pathophysiology of IR in RPL for potential prevention and therapeutic targets.

Satiety, Taste and the Cephalic Phase: A Crossover Designed Pilot Study into Taste and Glucose Response

The glycemic response produced by a food depends on both the glycemic index of the food itself, and on how the body reacts to the food as it is consumed and digested, in turn dependent on sensory cues. Research suggests that taste stimulation can induce the cephalic phase insulin response before food has reached the digestion, priming the body for an incoming glucose load. This glycemic response can consequently affect the amount of food consumed in a subsequent meal. The aim of this study was to investigate the effects on satiety of four preloads that differed in caloric content and sensory properties, in a small group of female and male participants (n = 10). Water, sucrose, sucralose, and maltodextrin were used to represent 4 different conditions of the preload, with or without energy, and with or without sweet taste. Individual plasma glucose concentrations were sampled at baseline, 45 min after consuming the preload, and after consuming an ad-libitum test meal. Hunger, fullness, desire to eat, and thoughts of food feeling were assessed every 15 min using visual analog scales. Results in male participants when comparing two solutions of equal caloric content, maltodextrin and sucrose, showed that plasma glucose concentration spiked in the absence of taste input (p = 0.011). Maltodextrin, while providing calories does not have the sweet taste that can serve to trigger cephalic phase insulin release to attenuate an incoming glucose load, and was accompanied by significantly greater change in feelings of satiety than with the other preloads. Despite the difference in postprandial blood glucose, the energy consumed in the test meal across the treatments was not significantly different in either males or females. Results highlight the importance of taste in stimulating the body for the efficient and effective glucose homeostasis.

MBOAT7 down-regulation by genetic and environmental factors predisposes to MAFLD

Metabolic associated fatty liver disease (MAFLD) encompasses a broad spectrum of hepatic disorders, which include steatosis, nonalcoholic steatohepatitis (NASH), fibrosis and cirrhosis, that is a critical risk factor for hepatocellular carcinoma (HCC) development. Its pathogenesis is intertwined with obesity and type 2 diabetes (T2D). However, the predisposition to develop MAFLD is severely influenced by environmental and inherited cues. The rs641738 variant close to MBOAT7 gene has been identified by a genome-wide association screening in heavy drinkers. Although this variant has been associated with the entire spectrum of MAFLD, these results have not been completely replicated and the debate is still opened. Thus, functional studies that unravel the biological mechanisms underlying the genetic association with fatty liver are required. This review aims to summarize the clinical and experimental findings regarding the rs641738 variation and MBOAT7 function, with the purpose to shed light to its role as novel player in MAFLD pathophysiology.

Ginger and avocado as nutraceuticals for obesity and its comorbidities

Obesity is a worldwide epidemic and is one of the factors involved in the etiology of type 2 diabetes mellitus. Obesity induces low-grade inflammation and oxidative stress. The treatment for obesity involves changes in diet, physical activity, and even medication and surgery. Currently, the use of nutraceutical compounds is associated with health benefits. Ginger and avocado are used for many people all around the world; however, its effect as a nutraceutical compound is less known by the general population. For this reason, we searched information of the literature to point its effects on distinct mechanisms of defense against the obesity its comorbidities. The present review aimed showing that these nutraceuticals may be useful in obesity treatment. Reports have shown that ginger and avocado induce antioxidant and anti-inflammatory effects by improving enzymatic activity and modulating obesity-related impairments in the anti-inflammatory system in different tissues, without side effects. Furthermore, ginger and avocado were found to be effective in reversing the harmful effects of obesity on blood lipids. In conclusion, on the basis of the positive effects of ginger and avocado in in vitro, animal, and human studies, these nutraceuticals may be useful in obesity treatment.

Association between Serum Ferritin and Blood Lipids: Influence of Diabetes and hs-CRP Levels

This study is aimed at exploring the relationship between serum ferritin and blood lipids and the influence of diabetes and different hs-CRP levels. A total of 8163 subjects were analyzed. Participators were classified according to serum ferritin, diabetes, and two hs-CRP levels. Blood lipids were determined using standardized methods and conditions. Except for HDL-C, there was a significant increase in blood lipids in the progressive ferritin group with normal hs-CRP levels (P < 0.05). But HDL-C was just the opposite (P < 0.0001). In nondiabetic patients, TG, TC, and LDL-C were significantly elevated in the progressive ferritin group (P < 0.05). And, HDL-C was just the opposite (P < 0.05). The generalized linear model and the parsimonious model showed that serum TG was positively correlated with ferritin, and LDL-C was negatively correlated with ferritin (P < 0.05). But the correlation between LDL-C and ferritin was broken (P > 0.05). After a sufficient adjustment, there was a positive correlation between serum TG and ferritin and a negative correlation between LDL-C and ferritin. Nonetheless, a negative correlation between LDL-C and ferritin is influenced by diabetes frailly. And, there was no change of relationship between lipids and ferritin in different hs-CRP levels. We found a real relationship between ferritin and lipids after sufficient adjustment for confounders.

Primary defects in lipid handling and resistance to exercise in myotubes from obese donors with and without type 2 diabetes

Several studies have shown that human primary myotubes retain the metabolic characteristic of their donors in vitro. We have demonstrated, along with other researchers, a reduced lipid turnover and fat oxidation rate in myotubes derived from obese donors with and without type 2 diabetes (T2D). Because exercise is known to increase fat oxidative capacity in skeletal muscle, we investigated if in vitro exercise could restore primary defects in lipid handling in myotubes of obese individuals with and without T2D compared with lean nondiabetic donors. Primary myotubes cultures were derived from biopsies of lean, obese, and T2D subjects. One single bout of long-duration exercise was mimicked in vitro by electrical pulse stimulation (EPS) for 24 h. Lipid handling was measured using radiolabeled palmitate, metabolic gene expression by real-time qPCR, and proteins by Western blot. We first showed that myotubes from obese and T2D donors had increased uptake and incomplete oxidation of palmitate. This was associated with reduced mitochondrial respiratory chain complex II, III, and IV protein expression in myotubes from obese and T2D subjects. EPS stimulated palmitate oxidation in lean donors, while myotubes from obese and T2D donors were refractory to this effect. Interestingly, EPS increased total palmitate uptake in myotubes from lean donors while myotubes from T2D donors had a reduced rate of palmitate uptake into complex lipids and triacylglycerols. Novelty Myotubes from obese and T2D donors are characterized by primary defects in palmitic acid handling. Both obese and T2D myotubes are partially refractory to the beneficial effect of exercise on lipid handling.

Lifestyle and Food Habits Impact on Chronic Diseases: Roles of PPARs

Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors that exert important functions in mediating the pleiotropic effects of diverse exogenous factors such as physical exercise and food components. Particularly, PPARs act as transcription factors that control the expression of genes implicated in lipid and glucose metabolism, and cellular proliferation and differentiation. In this review, we aim to summarize the recent advancements reported on the effects of lifestyle and food habits on PPAR transcriptional activity in chronic disease.

Triglyceride/glucose index is a reliable alternative marker for insulin resistance in South American overweight and obese children and adolescents

Background The aim of the present study was to investigate the correlation between the triglyceride/glucose index (TyG index) and homeostasis model assessment of insulin resistance (HOMA-IR). Additionally, we compared the ability of the TyG index and triglycerides/high-density lipoprotein cholesterol (TG/HDL-c) index and the combination of these two indices (TyG index plus TG/HDL-c) to predict insulin resistance (IR) in South American overweight and obese children and adolescents. Methods A cross-sectional study was carried out in 345 overweight adolescents aged 10-18 years, from both the sexes. The TyG index was calculated as Ln (fasting triglycerides [mg/dL] × fasting glucose [mg/dL])/2, while the TG/HDL-c index was calculated by the division of TG (mg/dL) by HDL-c (mg/dL). HOMA-IR was calculated with the formula: fasting insulin (FI) (U/mL) × fasting glucose (mmol/L)/22.5. The cut-off point used to determine the presence of IR was HOMA-IR ≥ 3.16. Results The TyG index showed a positive correlation with HOMA-IR. The area under the receiver operating characteristic (ROC) curve of the TyG index was 0.74, indicating good sensitivity (75.7%) and specificity (67.4%). Furthermore, the TyG index cut-off point of >4.44 was established for IR prediction in this population. Conclusions The TyG index is a simple and cost-effective surrogate marker of IR in South American overweight children and adolescents. Moreover, due to its good accessibility, it can be used in large epidemiological studies.

Association between adiponectin rs17300539 and rs266729 gene polymorphisms with serum adiponectin level in an Iranian diabetic/pre-diabetic population

OBJECTIVE

Adiponectin is an adipokine that is mostly secreted from adipose tissues and has a significant role in the improvement of insulin resistant and type 2 diabetes mellitus (T2DM). This study is conducted to examine the association of rs17300539 and rs266729 with T2DM and serum adiponectin level in Iranian population.

METHOD

A case-control study was conducted on 80 individuals with fasting plasma glucose (FPG) >100 (mg/dl) as diabetic-pre-diabetic group, and 80 individuals with fasting plasma glucose 70-100 (mg/dl) as control group. DNA extraction was done on samples and genotyping method was performed by PCR-RFLP.

RESULT

The frequency of GA genotype in rs17300539 (diabetic/pre-diabetic 35.5%, control 11.3%, (OR [95%CI]=4.18[1.8-9.6]; p=0.001) and allele A (diabetic/pre-diabetic 31%, control 9%, (OR [95% CI]=4.67[2-10.7]) was significantly more in diabetic/pre-diabetic group compared to control group. The difference in the genotype frequency for rs266729 in diabetic group compared to that in control was not significant. The levels of adiponectin in diabetic cases had no difference compared to the control group in both polymorphisms. The rs266729 was not associated with any metabolic parameter except waist circumference (p=0.03), however, rs17300539 shows association only with fasting plasma glucose, triglyceride, and total cholesterol (p=0.007, 0.039, 0.0032, respectively).

CONCLUSION

Our findings showed that there is an association between rs17300539 with the increase of T2DM but rs266729 showed no association with the risk of T2DM. Allele A of rs17300539 increased the risk of diabetes. There is no association between adiponectin level and both polymorphisms.

Berberine in Cardiovascular and Metabolic Diseases: From Mechanisms to Therapeutics

Cardiovascular and metabolic diseases (CVMD) are the leading causes of death worldwide, underscoring the urgent necessity to develop new pharmacotherapies. Berberine (BBR) is an eminent component of traditional Chinese and Ayurvedic medicine for more than 2000 years. Recently, BBR has attracted much interest for its pharmacological actions in treating and/or managing CVMD. Recent discoveries of basic, translational and clinical studies have identified many novel molecular targets of BBR (such as AMPK, SIRT1, LDLR, PCSK9, and PTP1B) and provided novel evidences supporting the promising therapeutic potential of BBR to combat CVMD. Thus, this review provides a timely overview of the pharmacological properties and therapeutic application of BBR in CVMD, and underlines recent pharmacological advances which validate BBR as a promising lead drug against CVMD.

Interplay of Glycemic Index, Glycemic Load, and Dietary Antioxidant Capacity with Insulin Resistance in Subjects with a Cardiometabolic Risk Profile

Background: Dietary total antioxidant capacity (TAC), glycemic index (GI), and glycemic load (GL) are accepted indicators of diet quality, which have an effect on diet–disease relationships. The aim of this study was to evaluate potential associations of dietary TAC, GI, and GL with variables related to nutritive status and insulin resistance (IR) risk in cardiometabolic subjects. Methods: A total of 112 overweight or obese adults (age: 50.8 ± 9 years old) were included in the trial. Dietary intake was assessed by a validated 137-item food frequency questionnaire (FFQ), which was also used to calculate the dietary TAC, GI, and GL. Anthropometrics, blood pressure, body composition by dual-energy X-ray absorptiometry (DXA), glycemic and lipid profiles, C-reactive protein (CRP), as well as fatty liver quantification by magnetic resonance imaging (MRI) were assessed. Results: Subjects with higher values of TAC had significantly lower circulating insulin concentration and homeostatic model assessment of insulin resistance (HOMA-IR). Participants with higher values of HOMA-IR showed significantly higher GI and GL. Correlation analyses showed relevant inverse associations of GI and GL with TAC. A regression model evidenced a relationship of HOMA-IR with TAC, GI, and GL. Conclusion: This data reinforces the concept that dietary TAC, GI, and GL are potential markers of diet quality, which have an impact on the susceptible population with a cardiometabolic risk profile.

Abdominal obesity and insulin resistance after an episode of acute pancreatitis

BACKGROUND

Emerging evidence indicates that individuals after an episode of acute pancreatitis (AP) are at an increased risk of developing metabolic derangements. While the link between general obesity and insulin resistance (IR) is well established, only a few studies have investigated the association between abdominal obesity and IR. The aim of this study was to investigate the associations between abdominal obesity and several indices of IR in individuals after an episode of AP.

METHODS

Patients were eligible for this cross-sectional study if they were previously admitted with a primary diagnosis of AP based on the recent international guidelines. Fasting venous bloods were collected to measure glucose, insulin, free fatty acids, glycerol, adiponectin (AD), omentin (OM), and vaspin (VAS). The IR indices - HOMA-IR, Adipo-IR, insulin*glycerol (IG) index, HOMA-AD, HOMA-OM, and HOMA-VAS were calculated. Modified Poisson regression was conducted, with statistical model adjusting for patient-, metabolic-, and pancreatitis-related risk factors. Areas under ROC curve were calculated and Bland-Altman plots were created.

RESULTS

Of the 92 individuals recruited, 41 had abdominal obesity. HOMA-IR, IG index, HOMA-OM, and HOMA-VAS were significantly associated with abdominal obesity, both in unadjusted and adjusted models. Area under ROC curves for HOMA-IR, IG index, HOMA-OM, and HOMA-VAS were 0.698, 0.695, 0.756, and 0.735, respectively. There was a good agreement between observed HOMA-IR values and values obtained from HOMA-OM (P = 0.733) and HOMA-VAS (P = 0.595).

CONCLUSION

Individuals with abdominal obesity after AP have a significantly higher IR, independent of diabetes and other covariates. Visceral adipose tissue specific adipokines, omentin and vaspin, hold promise for future clinical investigation of tissue-specific IR.

The extracellular domain of Staphylococcus aureus LtaS binds insulin and induces insulin resistance during infection

Insulin resistance is a risk factor for obesity and diabetes and predisposes individuals to Staphylococcus aureus colonization; however, the contribution of S. aureus to insulin resistance remains unclear. Here, we show that S. aureus infection causes impaired glucose tolerance via secretion of an insulin-binding protein extracellular domain of LtaS, eLtaS, which blocks insulin-mediated glucose uptake. Notably, eLtaS transgenic mice (eLtaS ^trans ) exhibited a metabolic syndrome similar to that observed in patients, including increased food and water consumption, impaired glucose tolerance and decreased hepatic glycogen synthesis. Furthermore, transgenic mice showed significant metabolic differences compared to their wild-type counterparts, particularly for the early insulin resistance marker α-hydroxybutyrate. We subsequently developed a full human monoclonal antibody against eLtaS that blocked the interaction between eLtaS and insulin, which effectively restored glucose tolerance in eLtaS ^trans and S. aureus-challenged mice. Thus, our results reveal a mechanism for S. aureus-induced insulin resistance.

Metabolic Vascular Syndrome: New Insights into a Multidimensional Network of Risk Factors and Diseases

BACKGROUND

Since 1981, we have used the term metabolic syndrome to describe an association of a dysregulation in lipid metabolism (high triglycerides, low high-density lipoprotein cholesterol, disturbed glucose homeostasis (enhanced fasting and/or prandial glucose), gout, and hypertension), with android obesity being based on a common soil (overnutrition, reduced physical activity, sociocultural factors, and genetic predisposition). We hypothesized that main traits of the syndrome occur early and are tightly connected with hyperinsulinemia/insulin resistance, procoagulation, and cardiovascular diseases.

METHODS

To establish a close link between the traits of the metabolic vascular syndrome, we focused our literature search on recent original work and comprehensive reviews dealing with the topics metabolic syndrome, visceral obesity, fatty liver, fat tissue inflammation, insulin resistance, atherogenic dyslipidemia, arterial hypertension, and type 2 diabetes mellitus.

RESULTS

Recent research supports the concept that the metabolic vascular syndrome is a multidimensional and interactive network of risk factors and diseases based on individual genetic susceptibility and epigenetic changes where metabolic dysregulation/metabolic inflexibility in different organs and vascular dysfunction are early interconnected.

CONCLUSION

The metabolic vascular syndrome is not only a risk factor constellation but rather a life-long abnormality of a closely connected interactive cluster of developing diseases which escalate each other and should continuously attract the attention of every clinician.

Early Effects of Treatment Low-Dose Atorvastatin on Markers of Insulin Resistance and Inflammation in Patients with Myocardial Infarction

Dyslipidemia is one of the primary causes of cardiovascular disease. Therefore, attention has been focused on the development of drugs that normalize lipid levels and exert an effect on markers of atherothrombosis, insulin resistance (IR), and inflammation. Atorvastatin is a drug with not only lipid-lowering potential, but it has multiple non-lipid effects. This study aimed to evaluate atorvastatin effects on lipid, adipokine, IR, and inflammatory statuses in patients with myocardial infarction (MI) in an in-hospital setting. This study included 66 patients with confirmed ST-segment elevation MI, who were treated with atorvastatin 20 mg/day starting on day 1 of MI, without any dose changes. The comparison group consisted of 60 patients receiving standard anti-anginal and anti-thrombotic therapy. During the hospital stay, both groups showed a reduction in total cholesterol level and free fatty acids and increased concentrations of apolipoprotein A, especially those patients receiving atorvastatin. On day 1 of MI, patients in both groups had elevated levels of leptin by 2.9- to 3.3-fold, but the leptin levels decreased by 40.3% and were significantly lower than in patients not taking statins. The treatment with atorvastatin was associated with a decrease in C-reactive protein and interleukin-6 by 23.1 and 49.2%, respectively, compared with baseline values. In the group of patients on standard therapy, there was a decrease of interleukin-6 by 31.7%. Atorvastatin administered early on during hospitalization to patients with MI contributed to the improvement of lipid, adipokine and pro-inflammatory statuses and decreased IR.

Pancreatic Islet Responses to Metabolic Trauma

Carbohydrate, lipid, and protein metabolism are largely controlled by the interplay of various hormones, which includes those secreted by the pancreatic islets of Langerhans. While typically representing only 1% to 2% of the total pancreatic mass, the islets have a remarkable ability to adapt to disparate situations demanding a change in hormone release, such as peripheral insulin resistance. There are many different routes to the onset of insulin resistance, including obesity, lipodystrophy, glucocorticoid excess, and the chronic usage of atypical antipsychotic drugs. All of these situations are coupled to an increase in pancreatic islet size, often with a corresponding increase in insulin production. These adaptive responses within the islets are ultimately intended to maintain glycemic control and to promote macronutrient homeostasis during times of stress. Herein, we review the consequences of specific metabolic trauma that lead to insulin resistance and the corresponding adaptive alterations within the pancreatic islets.

Endothelial Damage and Hemostatic Markers in Patients with Uncomplicated Mild-to-Moderate Hypertension and Relationship with Risk Factors

Endothelial damage, high fibrinogen levels, and platelet activity are the important accelerating factors for the development of hypertension (HT). von Willebrand factor (vWF; endothelial damage marker), fibrinogen levels, and platelet aggregability were compared between patients with uncomplicated, mild-to-moderate hypertension and healthy subjects. The relationship between traditional cardiovascular risk factors and endothelial damage and prothrombotic state was evaluated. One hundred sixty-nine (54 males, 115 females) patients with untreated and uncomplicated mild-to-moderate HT, and age, gender, and body mass index-matched 124 (58 males, 83 females) healthy subjects were enrolled in this study. Plasma vWF, fibrinogen levels, adenosine diphosphate-induced platelet aggregability, insulin, glucose, serum lipids, and uric acid were measured. Patients with HT had significantly increased fibrinogen, vWF, platelet number and aggregability induced by adenosine diphosphate, triglycerides, total/HDL-C, glucose, uric acid levels, and insulin resistance than control group. vWF and hemostatic markers were comparable between smoker and nonsmoker subjects. Platelet aggregability was positively related to systolic and diastolic blood pressure, and vWF. Fibrinogen was positively associated with body mass index (BMI), systolic and diastolic blood pressure, total cholesterol (TC), uric acid, vWF, and insulin resistance. vWF was significantly related to age, systolic blood pressure, TC, LDL-C, and total/HDL-C. Systolic blood pressure was independently related to vWF. vWF and diastolic blood pressure were significant predictors for adenosine diphosphate-induced platelet aggregability. Systolic blood pressure and vWF were independent predictors for fibrinogen levels. Uncomplicated mild-to-moderate HT had endothelial damage and is associated with a prothrombotic state. Traditional cardiovascular risk factors such as age, BMI, dyslipidemia, and insulin resistance are important contributors to the development of endothelial damage and a prothrombotic state. Therefore, it is important to control these cardiovascular risk factors along with proper treatment of HT for preventing target organ damage in mild-to-moderate HT.

Effect of an avocado oil-enhanced diet ( Persea americana ) on sucrose-induced insulin resistance in Wistar rats

A number of studies have been conducted to evaluate the effects of vegetable oils with varying percentages of monounsaturated and polyunsaturated fatty acids on insulin resistance. However, there is no report on the effect of avocado oil on this pathologic condition. The aim of this work was to evaluate the effect of avocado oil on sucrose-induced insulin resistance in Wistar rats. An experimental study was carried out on Wistar rats that were randomly assigned into six groups. Each group received a different diet over an 8-week period (n = 11 in each group): the control group was given a standard diet, and the other five groups were given the standard feed plus sucrose with the addition of avocado oil at 0%, 5%, 10%, 20%, and 30%, respectively. Variables were compared using Student t test and analysis of variance. Statistically significant difference was considered when p < 0.05. Rats that were given diets with 10% and 20% avocado oil showed lower insulin resistance (p = 0.022 and p = 0.024, respectively). Similar insulin resistance responses were observed in the control and 30% avocado oil addition groups (p = 0.85). Addition of 5–30% avocado oil lowered high sucrose diet-induced body weight gain in Wistar rats. It was thus concluded that glucose tolerance and insulin resistance induced by high sucrose diet in Wistar rats can be reduced by the dietary addition of 5–20% avocado oil.

Insulin resistance in obesity and polycystic ovary syndrome: systematic review and meta-analysis of observational studies

We aimed at investigating whether insulin resistance (IR)/sensitivity are impaired in obese/non-obese polycystic ovary syndrome (PCOS) and obese/non-obese healthy controls. A comprehensive literature search was performed for observational, English language studies. Meta-analysis was performed with the random effects model according to the heterogeneity. Eligible studies, involving 3037 women in four groups of: 1-obese, PCOS; 2-non-obese, PCOS, 3-obese, non-PCOS and 4-Non-obese, non-PCOS were included. Based on the insulin resistance index (HOMA-IR) analysis, the pooled mean (95% Conf. Interval) of HOMA IR in groups 1-4 were 4.38 (3.84, 4.92), 2.68 (2.16, 3.20), 2.44 (2.06, 2.82) and 1.34 (1.06, 1.63), respectively. Meta-analysis showed that group 1 (obese, PCOS patients) statistically have the highest IR and group 4 (non-obese, non-PCOS women) have the highest insulin sensitivity. Group 2 (non-obese, PCOS patients) and group 3 (obese, non-PCOS women) were between this range and they had lower IR than group 1 (obese, PCOS) and lower insulin sensitivity than group 4 (non-obese, non-PCOS). So, there were statistical differences between all groups except between groups 2 and 3. Insulin sensitivity indexes (quickie and ISI), also confirm the IR index (HOMA-IR) results. Based on different IR/sensitivity indexes, we found no evidence of any different effects of BMI ≥ 30 kg/m(2) on IR/sensitivity. In conclusion, PCOS status intensifies the adverse effects of obesity on IR, it has to be appropriately addressed in primary and secondary preventive cares and treatments provided for these women.

Dose-dependent effects of atorvastatin on myocardial infarction

Background

Dyslipidemia is a key factor determining the development of both myocardial infarction (MI) and its subsequent complications. Dyslipidemia is associated with endothelial dysfunction, activation of inflammation, thrombogenesis, and formation of insulin resistance. Statin therapy is thought to be effective for primary and secondary prevention of complications associated with atherosclerosis.

Methods

This study examined 210 patients with Segment elevated MI (ST elevated MI) who were treated with atorvastatin from the first 24 hours after MI. Group 1 (n=110) were given atorvastatin 20 mg/day. Group 2 (n=100) were given atorvastatin 40 mg/day. At days 1 and 12 after MI onset, insulin resistance levels determined by the homeostasis model assessment of insulin resistance index, lipid profiles, and serum glucose, insulin, adipokine, and ghrelin levels were measured.

Results

Free fatty acid levels showed a sharp increase during the acute phase of MI. Treatment with atorvastatin 20 mg/day, and especially with 40 mg/day, resulted in a decrease in free fatty acid levels. The positive effect of low-dose atorvastatin (20 mg/day) is normalization of the adipokine status. Administration of atorvastatin 20 mg/day was accompanied with a statistically significant reduction in glucose levels (by 14%) and C-peptide levels (by 38%), and a decrease in the homeostasis model assessment of insulin resistance index on day 12.

Conclusion

Determination of atorvastatin dose and its use during the in-hospital period and subsequent periods should take into account changes in biochemical markers of insulin resistance and adipokine status in patients with MI.

The Macrophage Switch in Obesity Development

Immune cell infiltration in (white) adipose tissue (AT) during obesity is associated with the development of insulin resistance. In AT, the main population of leukocytes are macrophages. Macrophages can be classified into two major populations: M1, classically activated macrophages, and M2, alternatively activated macrophages, although recent studies have identified a broad range of macrophage subsets. During obesity, AT M1 macrophage numbers increase and correlate with AT inflammation and insulin resistance. Upon activation, pro-inflammatory M1 macrophages induce aerobic glycolysis. By contrast, in lean humans and mice, the number of M2 macrophages predominates. M2 macrophages secrete anti-inflammatory cytokines and utilize oxidative metabolism to maintain AT homeostasis. Here, we review the immunologic and metabolic functions of AT macrophages and their different facets in obesity and the metabolic syndrome.

Effects of eugenol-reduced clove extract on glycogen phosphorylase b and the development of diabetes in db/db mice

We found that the 50% aqueous EtOH extract of clove (Syzygium aromaticum) had potent dose-dependent inhibitory activity toward glycogen phosphorylase b and glucagon-stimulated glucose production in primary rat hepatocytes. Among the components, eugeniin inhibited glycogen phosphorylase b and glucagon-stimulated glucose production in primary rat hepatocytes, with IC50 values of 0.14 and 4.7 μM, respectively. In sharp contrast, eugenol showed no significant inhibition toward glycogen phosphorylase b, even at a concentration of 400 μM. Eugenol-reduced clove extracts (erCE) were prepared and when fed to a db/db mouse they clearly suppressed the blood glucose and HbA1c levels. Furthermore, plasma triglyceride and non-esterified fatty acid levels in 5% and 10% erCE-fed db/db mice were significantly lowered, compared with control db/db mice without erCE supplementation. These results suggested that dietary supplementation with the erCE could beneficially modify glucose and lipid metabolism and contribute to the prevention of the progress of hyperglycemia and metabolic syndrome.