Progression of insulin resistance: A link between risk factors and the incidence of diabetes

Exploring the therapeutic potential of Derris elliptica (Wall.) Benth in Streptozotocin-Induced diabetic Rats: Phytochemical characterization and antidiabetic evaluation

Derris elliptica (Wall.) Benth, a native medicinal plant, has been used to treat diabetes for centuries; however, comprehensive documentation of its bioactive constituents and therapeutic effectiveness is lacking. In this study, we investigated the phytochemical profile and antidiabetic potential of D. elliptica methanolic leaf extract (DEME) in diabetic Sprague Dawley rats induced with streptozotocin (STZ). In normal rats, acute oral toxicity evaluations were conducted, and in STZ-induced rats, antidiabetic properties were investigated. 14 days of oral administration of standard glibenclamide and the extract at 200 and 400 mg/kg body weight to diabetic rodents. Assessed parameters included blood glucose levels, alterations in body weight, biochemical markers, and histological analysis of the pancreas, liver, and kidney. Numerous phytoconstituents were uncovered through qualitative phytochemical assays, 1H NMR, and 1H-13C HSQC screening. Quercetin was identified by 1H NMR characterization, and a ceramide analogue compound was isolated and partially characterized by 1H NMR. There were no indications of toxicity or mortality. The treatment with DEME significantly (p < 0.001) decreased body weight and had a remarkable hypoglycemic effect. Both 200 mg/kg and 400 mg/kg extract concentrations decreased total cholesterol levels significantly (p < 0.01 and p < 0.05, respectively). In addition, glibenclamide and the 400 mg/kg dose of extract increased serum insulin levels substantially (p < 0.05) and decreased total bilirubin, lactic acid dehydrogenase, aspartate aminotransferase, and alanine aminotransferase levels. In addition to glibenclamide, treatment with DEME has exhibited cytoprotective effects and increased insulin secretion, thereby exerting a potent antihyperglycemic effect. These results suggest that D. elliptica may have therapeutic potential for the treatment of diabetes mellitus.

The mediation effect of asprosin on the association between ambient air pollution and diabetes mellitus in the elderly population in Taiyuan, China

Evidence around the relationship between air pollution and the development of diabetes mellitus (DM) remains limited and inconsistent. To investigate the potential mediation effect of asprosin on the association between fine particulate matter (PM2.5), tropospheric ozone (O3) and blood glucose homeostasis. A case-control study was conducted on a total of 320 individuals aged over 60 years, including both diabetic and non-diabetic individuals, from six communities in Taiyuan, China, from July to September 2021. Generalized linear models (GLMs) suggested that short-term exposure to PM2.5 was associated with elevated fasting blood glucose (FBG), insulin resistance index (HOMA-IR), as well as reduced pancreatic β-cell function index (HOMA-β), and short-term exposure to O3 was associated with increased FBG and decreased HOMA-β in the total population and elderly diabetic patients. Mediation analysis showed that asprosin played a mediating role in the relationship of PM2.5 and O3 with FBG, with mediating ratios of 10.2% and 18.4%, respectively. Our study provides emerging evidence supporting that asprosin mediates the short-term effects of exposure to PM2.5 and O3 on elevated FBG levels in an elderly population. Additionally, the elderly who are diabetic, over 70 years, and BMI over 24 kg/m2 are more vulnerable to air pollutants and need additional protection to reduce their exposure to air pollution.

Serum vascular adhesion protein-1 is associated with twelve-year risk of incident cancer, cancer mortality, and all-cause mortality: a community-based cohort study

Background

Vascular adhesion protein-1 (VAP-1), a dual-function glycoprotein, has been reported to play a crucial role in inflammation and tumor progression. We conducted a community-based cohort study to investigate whether serum VAP-1 could be a potential biomarker for predicting incident cancers and mortality.

Method

From 2006 to 2018, we enrolled 889 cancer-free subjects at baseline. Serum VAP-1 levels were measured using a time-resolved immunofluorometric assay. Cancer and vital status of the participants were obtained by linking records with the computerized cancer registry and death certificates in Taiwan.

Results

During a median follow-up of 11.94 years, 69 subjects developed incident cancers and 66 subjects died, including 29 subjects who died from malignancy. Subjects in the highest tertile of serum VAP-1 had a significantly higher risk of cancer incidence (p=0.0006), cancer mortality (p=0.0001), and all-cause mortality (p=0.0002) than subjects in the other tertiles. The adjusted hazard ratios per one standard deviation increase in serum VAP-1 concentrations were 1.28 for cancer incidence (95% CI=1.01-1.62), 1.60 for cancer mortality (95% CI=1.14-2.23), and 1.38 for all-cause mortality (95% CI=1.09-1.75). The predictive performance of serum VAP-1 was better than that of gender, smoking, body mass index, hypertension, diabetes, and estimated glomerular filtration rate but lower than that of age for cancer incidence, cancer mortality, and all-cause mortality, as evidenced by higher increments in concordance statistics and area under the receiver operating characteristic curve.

Conclusion

Serum VAP-1 levels are associated with a 12-year risk of incident cancer, cancer mortality, and all-cause mortality in a general population.

Metformin inhibits cardiometabolic syndrome associated cognitive deficits in high fat diet rats

Objectives

Glucose intolerance and insulin resistance are hallmarks of metabolic syndrome and lead to Alzheimer's disease (AD). The purpose of this study is to elucidate the neuroprotective effect of metformin through insulin regulation with cardiometabolic and neurotransmitter metabolic enzyme regulation in high-fat, high-sucrose diet and streptozotocin (HFHS-STZ)-induced rats.

Methods

Male Wistar rats were treated with metformin (180 mg/kg and 360 mg/kg). STZ (35 mg/kg i.p.) injection was performed on the 14th day of 42 days of HFHS diet treatment. Brain neurotransmitter metabolic enzymes (acetylcholinesterase and monoamine oxidase) were determined along with sodium-potassium ATPase (Na+K+-ATPase). Plasma lipids and homeostasis model assessment of insulin resistance (HOMA-IR) was performed. Mean arterial blood pressure, heart rate and electrocardiogram (QT, QTc and RR intervals) were analysed with PowerLab.

Results

Metformin treatment significantly (p < 0.001) reduced the HOMA-IR index and decreased neurotransmitter metabolic enzymes such as AChE and MAO (p < 0.01 and p < 0.05). The lipid profile was significantly (p < 0.001) controlled with cardiometabolic functions.

Conclusions

Our investigation revealed that metformin has a remarkable role in regulating brain insulin, vascular system with monoaminergic metabolic enzymes and enhancing synaptic plasticity. Metformin may be a selective early therapeutic agent in metabolic syndrome associated with cognitive decline.

Factors Associated With Discordant A1C-Estimated and Measured Average Glucose Among Hospitalized Patients With Diabetes

In this retrospective analysis, we explored the correlation between measured average glucose (mAG) and A1C-estimated average glucose (eAG) in hospitalized patients with diabetes and identified factors associated with discordant mAG and eAG at the transition from home to hospital. Having mAG lower than eAG was associated with Black race, other race, increasing length of stay, community hospital setting, surgery, fever, metformin use, certain inpatient diets, home antihyperglycemic treatment, and coded type 1 or type 2 diabetes. Having mAG higher than eAG was associated with certain discharge services (e.g., intensive care unit), higher BMI, hypertension, tachycardia, higher albumin, higher potassium, anemia, inpatient glucocorticoid use, and treatment with home insulin, secretagogues, and glucocorticoids. These factors should be considered when using patients' A1C as an indicator of outpatient glycemic control to determine the inpatient antihyperglycemic regimens.

Insulin resistance in people living with HIV is associated with exposure to thymidine analogues and/or didanosine and prior immunodeficiency

Background

As people living with HIV (PLWH) are growing older, there is increased incidence of metabolic diseases, including type 2 diabetes mellitus, for which insulin resistance is a key determinant. In this study, we aimed to investigate risk factors associated with insulin resistance in PLWH.

Methods

We included well-treated PLWH without hepatitis co-infection, and with available fasting serum insulin and plasma glucose (n = 643) from the Copenhagen Comorbidity in HIV Infection Study. Insulin resistance was calculated using the homeostasis model assessment of insulin resistance (HOMA-IR). We investigated the association between risk factors and high HOMA-IR in a logistic regression model adjusted for age, sex, abdominal obesity, smoking status, and origin. When including use of thymidine analogues and/or didanosine in the model, we also adjusted for time with HIV.

Results

Median (IQR) age of PLWH was 52 years (46–61), and 87% (n = 557) were male. Median (IQR) HOMA-IR was 1.86 (1.23–3.14) mmol/L × mU/L. Risk factors significantly associated with high HOMA-IR included older age, BMI ≥ 25, abdominal obesity, waist circumference, use of thymidine analogues and/or didanosine, time with HIV, and CD4⁺ nadir < 200 cells/µL.

Conclusions

Insulin resistance in PLWH is associated with both use of thymidine analogues and/or didanosine and prior immunodeficiency suggesting that increased attention on blood glucose in these patients could be beneficial.

Insulin Resistance Is Cheerfully Hitched with Hypertension

Cardiovascular diseases and type 2 diabetes mellitus (T2DM) have risen steadily worldwide, particularly in low-income and developing countries. In the last hundred years, deaths caused by cardiovascular diseases increased rapidly to 35–40%, becoming the most common cause of mortality worldwide. Cardiovascular disease is the leading cause of morbidity and mortality in type 2 diabetes mellitus (T2DM), which is aggravated by hypertension. Hypertension and diabetes are closely interlinked since they have similar risk factors such as endothelial dysfunction, vascular inflammation, arterial remodeling, atherosclerosis, dyslipidemia, and obesity. Patients with high blood pressure often show insulin resistance and have a higher risk of developing diabetes than normotensive individuals. It has been observed that over the last 30 years, the prevalence of insulin resistance (IR) has increased significantly. Accordingly, hypertension and insulin resistance are strongly related to an increased risk of impaired glucose tolerance, diabetes, cardiovascular diseases (CVD), and endocrine disorders. Common mechanisms, for instance, upregulation of the renin–angiotensin–aldosterone system, oxidative stress, inflammation, and activation of the immune system, possibly have a role in the association between diabetes and hypertension. Altogether these abnormalities significantly increase the risk of developing type 2 diabetes.

Association of mid-life cerebral small vessel disease with diabetic retinopathy in type 2 diabetes in an Indian population

PURPOSE

Prevalence of cerebral small vessel disease (SVD) in elderly patients with diabetic retinopathy (DR) is higher than in those without DR. We determined the prevalence and severity of SVD in middle-aged patients with DR and compared it with those without DR (NODR) in a subset of the Indian population. We feel this information is critical with evolving trends of an increasing incidence of stroke at younger ages.

METHOD

Institution-based analytical cross-sectional study with 88 middle-aged type 2 diabetes patients; 44 in each group with <10 years diabetes duration, <8% HbA1C value, and with no history of cardiovascular disease. The presence and severity of SVD were determined by magnetic resonance imaging (MRI).

RESULT

Prevalence of SVD was 59.1% among study participants; 70.5% in DR and 47.7% in NODR (p = .03). Significantly increased SVD score (p = .008), high SVD score (p = .030), and white matter hyperintensity (WMH) load (p = .017) were observed in DR compared to NODR. There was no difference in the load of lacune and microbleed. SVD score did not differ according to the severity of DR (p = .395). The location-wise study of MRI revealed a significantly higher SVD load at the centrum semiovale in DR than in NODR (p = .014). We observed a 2.6 times greater chance of SVD (Odds ratio: 2.6, 95% CI 1.1-6.3) and a 9.6 times greater chance of high SVD score (Odds ratio: 9.6, 95% CI 1.1-80.0) in DR compared to NODR.

CONCLUSION

Significantly higher burden of SVD in DR was observed, particularly affecting the centrum semiovale suggesting an association of mid-life SVD with DR in this population.

Changes in the Expression of Insulin Pathway, Neutrophil Elastase and Alpha 1 Antitrypsin Genes from Leukocytes of Young Individuals with Insulin Resistance

BACKGROUND

Chronic hyperinsulinemia is a hallmark of insulin resistance that affects a diversity of cells, including leukocytes modifying the expression of some genes involved in insulin signaling.

PURPOSE

The aim of this study was to evaluate how hyperinsulinemia affects the expression of genes involved in the proximal insulin signaling pathway in leukocytes from 45 young individuals grouped: normal weight with not insulin resistance (NIR), with insulin resistance (IR) and with obesity (OB-IR).

METHODS

qPCR was performed to analyze the expression of insulin receptor (INSR), insulin receptor substrate 1 and 2 (IRS-1 and IRS-2), neutrophil elastase (NE), alpha 1 antitrypsin (A1AT), glucose transporters 1, 3 and 4 (GLUT-1, GLUT-3 and GLUT-4) by the 2^-ΔCt method, and the correlation between the genes was determined by Spearman's test.

RESULTS

The mRNA expression analysis of all genes between NIR and IR individuals revealed no differences. However, when comparing NIR and IR individuals with OB-IR, an increase in NE and A1AT expression and a clear trend towards a decrease in IRS-2 expression was observed, whereas the comparison of IR and OB-IR showed a decrease in GLUT-3 expression. Overall, the correlation analysis showed that in the IR group there was a positive correlation only between NE with IRS-1 (r = 0.72, p = 0.003), while in the OB-IR group, there was a positive correlation between the NE and A1AT with INSR (r = 0.62, p = 0.01 and r = 0.74, p = 0.002, respectively) and with IRS-2 (r = 0.74, p = 0.002 and r = 0.76, p = 0.001, respectively).

CONCLUSION

These results suggest that hyperinsulinemia and obesity are associated with changes in the expression of genes in leukocytes involved in the insulin pathway that are related to NE and A1AT.

Novel Treatments from Inhibition of the Intestinal Sodium-Hydrogen Exchanger 3

Plasma membrane sodium–hydrogen exchangers (NHE) transport Na⁺ into cells in exchange for H⁺. While there are nine isoforms of NHE in humans, this review focuses on the NHE3 isoform, which is abundantly expressed in the gastrointestinal tract, where it plays a key role in acid–base balance and water homeostasis. NHE3 inhibition in the small intestine results in luminal sodium and water retention, leading to a general decrease in paracellular water flux and diffusional driving force, reduced intestinal sodium absorption, and increased stool sodium excretion. The resulting softer and more frequent stools are the rationale for the development of tenapanor as a novel, first-in-class NHE3 inhibitor to treat irritable bowel syndrome with constipation. NHE3 also has additional therapeutic implications in nephrology. Inhibition of intestinal NHE3 also lowers blood pressure by reducing intestinal sodium absorption. Perhaps, the most novel effect is its ability to decrease intestinal phosphate absorption by inhibiting the paracellular phosphate absorption pathway. Therefore, selective pharmacological inhibition of NHE3 could be a potential therapeutic strategy to treat not only heart failure and hypertension but also hyperphosphatemia. This review presents an overview of the molecular and physiological functions of NHE3 and discusses how these functions translate to potential clinical applications in nephrology.

Prenatal exposure to traffic-related air pollution and glucose homeostasis: A cross-sectional study

Air pollution exposure has been linked with glucose dysregulation in pregnant women; however, evidence on these associations with fetal glucose homeostasis is unclear yet. We therefore aimed to evaluate the association of prenatal exposure to particulate matter (PM) and traffic indicators with fetal glucose homeostasis in cord blood samples. A total of 169 mother-infant pairs recruited from Mobini hospital of Sabzevar, Iran, were included in this cross-sectional study. Maternal exposure to PMs was estimated using land use regression models. Moreover, traffic indicators (i.e., total street length in 100, 300 and 500 m buffers and distance from residential home to the nearest major roads) were calculated based on the street map of Sabzevar. Cord blood glucose and insulin concentrations, HOMA-ꞵ, HOMA-S and HOMA-IR were used as glucose homeostasis markers. Higher maternal exposure to PM_2.5 and PM₁₀ were associated with higher cord blood glucose and insulin concentrations and HOMA-IR. Moreover, total streets length in 300 m buffer was positively associated with cord blood glucose and insulin concentrations and HOMA-IR. An increase in distance to major roads was associated with higher HOMA-ꞵ and HOMA-S and lower cord blood glucose and insulin concentrations as well as HOMA-IR. Overall, we found prenatal exposure to PMs and traffic indicators was associated with a higher risk of glucose homeostasis dysregulation in the fetus.

Low Carbohydrate Dietary Approaches for People With Type 2 Diabetes-A Narrative Review

Although carbohydrate restriction is not a new approach for the management of Type 2 diabetes, interest in its safety and efficacy has increased significantly in recent years. The purpose of the current narrative review is to summarise the key relevant research and practical considerations in this area, as well as to explore some of the common concerns expressed in relation to the use of such approaches. There is a strong physiological rationale supporting the role of carbohydrate restriction for the management of Type 2 diabetes, and available evidence suggests that low carbohydrate dietary approaches (LCDs) are as effective as, or superior to, other dietary approaches for its management. Importantly, LCDs appear to be more effective than other dietary approaches for facilitating a reduction in the requirement for certain medications, which leads to their effects on other health markers being underestimated. LCDs have also been demonstrated to be an effective method for achieving remission of Type 2 diabetes for some people. The available evidence does not support concerns that LCDs increase the risk of cardiovascular disease, that such approaches increase the risk of nutrient deficiencies, or that they are more difficult to adhere to than other dietary approaches. A growing number of organisations support the use of LCDs as a suitable choice for individuals with Type 2 diabetes.

Effect of thymoquinone on high fat diet and STZ-induced experimental type 2 diabetes: A mechanistic insight by in vivo and in silico studies

The aim was to investigate whether thymoquinone (TQ) attenuates hyperglycemia-induced insulin resistance in experimental type 2 diabetes. Type 2 diabetes mellitus (T2DM) was induced by injection of streptozotocin (STZ, 40 mg/kg) in high fat diet (HFD) rats. The levels of glucose, insulin, area under curve (AUC) of glucose, lipid profile parameters, homeostasis model assessment of insulin resistance (HOMA-IR), peroxisome proliferator-activated receptor-γ (PPARγ), and dipeptidyl peptidase peptidase-IV (DPP-IV) were evaluated in HFD + STZ-induced type 2 diabetic rats. TQ treatment significantly reduced elevated levels of glucose, AUC of glucose, insulin, and DPP-IV in diabetic-treated groups. In addition, TQ treatment significantly reduced high levels of triglycerides (TG) and cholesterols (total, low-density and very low-density lipoprotein) accompanied by significant augmentation in high-density lipoprotein (HDL) levels in diabetic-treated groups. However, TQ treatment significantly improved insulin sensitivity in diabetic-treated groups, which was confirmed by increased level of PPARγ and decreased level of HOMA-IR. Molecular docking of TQ exhibited substantial binding affinity with PPARγ and DPP-IV target proteins, which is supported by in vivo results. These results demonstrate that TQ attenuates hyperglycemia-induced insulin resistance by counteracting hyperinsulinemia, improving lipid profile, insulin sensitivity, and inhibiting DPP-IV. PRACTICAL APPLICATIONS: T2DM results in relentless hyperglycemia which eventually progress to a state of insulin resistance. TQ is an active principle compound found in Nigella sative seed, having myriad of traditional medicinal values. Administration of TQ significantly prevented hyperglycemia, hyperinsulinemia, hyperlipidemia, insulin resistance, and inhibited DPP-IV in experimental type 2 diabetes. The in vivo results are also supported by molecular docking study of PPARγ and DPP-IV target proteins. Thus, we hypothesize that TQ can be used as an alternative natural drug in the management of hyperglycemia-induced insulin resistance in T2DM.

Different cutoffs of hypertension, risk of incident diabetes and progression of insulin resistance: A prospective cohort study

BACKGROUND/PURPOSE

Hypertension is a risk factor of incident diabetes. In 2017, the ACC/AHA updated the definition of hypertension to above 130/80 mmHg, while the 2018 ESC/ESH guideline and the JNC7 criteria remained the cutoff of 140/90 mmHg. This study was aimed to investigate how different cutoffs of hypertension affect the association of hypertension to incident diabetes and the progression of insulin resistance.

METHODS

A total of 1177 subjects without diabetes at baseline were followed for 4.5 years. Diabetes was diagnosed by the results of oral glucose tolerance tests and hemoglobin A1c, or if anti-diabetic agents were used.

RESULTS

Hypertension by both criteria was associated with incident diabetes. Change of HOMA2-IR every 5 years (ΔHOMA2-IR/5 yr) was higher in subjects with hypertension than those without (adjusted p = 0.044). Subjects with treated hypertension had the highest risk of diabetes (HR 2.98, p < 0.001) and ΔHOMA2-IR/5 yr, compared with subjects with normal blood pressure. However, the associations of hypertension, HR of incident diabetes and ΔHOMA2-IR/5 yr were attenuated by the 2017 ACC/AHA criteria, as compared with that by the JNC7 and 2018 ESC/ESH criteria.

CONCLUSION

Hypertension by both criteria is associated with incident diabetes and accelerated progression of insulin resistance, and the associations are attenuated by the 2017 ACC/AHA criteria.

Association Between Aspartate Aminotransferase to Alanine Aminotransferase Ratio and Incidence of Type 2 Diabetes Mellitus in the Japanese Population: A Secondary Analysis of a Retrospective Cohort Study

BACKGROUND

The study on the association between aspartate aminotransferase to alanine aminotransferase (AST/ALT) ratio and the risk of type 2 diabetes mellitus (T2DM) was limited. Therefore, we conducted a secondary analysis based on online data to explore whether there was an association between the AST/ALT ratio and incident T2DM among a large number of Japanese people.

METHODS

The study was a retrospective cohort study. We downloaded the NAGALA (NAfld in Gifu area) data from DATADRYAD website between 2004 and 2015. This present study included 15,291 participants. Cox proportional-hazards regression, generalized additive models and subgroup analyses were used to find out the association between the AST/ALT ratio and T2DM events.

RESULTS

The negative relationship was shown between AST/ALT ratio and incident T2DM (HR = 0.617, 95% CI: 0.405-0.938) in our study. A non-linear relationship and saturation effect were found between them, and the inflection point was 0.882. It indicated that the AST/ALT ratio was negatively correlated with incident T2DM when the AST/ALT ratio was less than the inflection point (HR = 0.287, 95% CI: 0.126-0.655, p = 0.0030). We found that exercise modified their relationship (P for interaction = 0.0024), and people who did not exercise associated strongly (HR = 0.464 95% CI: 0.290-0.741).

CONCLUSION

AST/ALT ratio was negatively associated with T2DM risk, and their relationship was non-linear and had a saturation effect. When the AST/ALT ratio was less than 0.882, they showed a significant negative correlation.

Approach to the cardiometabolic continuum. Narrative description

Atherosclerotic cardiovascular disease (ACVD) is the major adverse outcome in the evolution of several metabolic conditions. For around several decades, the cardiovascular continuum has been used as a fantastic tool to explain the evolution of ACVD from the onset of risk factor, to clinical outcomes, and to death. Nowadays, metabolic diseases such as obesity, prediabetes, and type2 diabetes have been increasing enough to become serious public health problems and notorious contributors to the morbidity and mortality rates due to ACVD, including arterial hypertension. Other conditions seem to increase the list, such as: physical inactivity with its metabolic cluster, sarcopenia, and non-alcoholic fatty liver disease (NAFLD). Moreover, obesity in childhood has been growing at an exponential rate so the excess of adiposity in children and adolescents will translate into an excess of cardiometabolic risk in adults. Several longitudinal studies confirm the strong association of paediatric obesity with the persistence of adult obesity, as well as the future development of cardiometabolic conditions, such as prediabetes, diabetes, obesity, increased risk of arterial hypertension, and ACVD. Therefore, it is time to conceptualise the cardiometabolic continuum as a tool of an early, wider and preventive intervention in order to reduce the morbidity and mortality due to ACVD.

Diagnosis of Diabetes Mellitus in Older Adults

In the United States, 4 out of 10 adults with diabetes are ≥65 years of age. The older adult with diabetes is very likely to be asymptomatic and also at higher risk of vascular disease. New concerns include new diagnosis of diabetes for older adults admitted to hospital and older adults in long-term care facilities. The pathophysiology for increased incidence of diabetes in older adults is multifactorial, but dominant features are increased likelihood of metabolic syndrome, dysfunctional insulin secretion, and peripheral insulin resistance. Society in general benefits from more cost-effective care of older adults with diabetes.