Diabetes-related microvascular and macrovascular diseases in the physical therapy setting

Oxidative Stress and Vascular Dysfunction in the Retina: Therapeutic Strategies

Many retinal diseases, such as diabetic retinopathy, glaucoma, and age-related macular (AMD) degeneration, are associated with elevated reactive oxygen species (ROS) levels. ROS are important intracellular signaling molecules that regulate numerous physiological actions, including vascular reactivity and neuron function. However, excessive ROS formation has been linked to vascular endothelial dysfunction, neuron degeneration, and inflammation in the retina. ROS can directly modify cellular molecules and impair their function. Moreover, ROS can stimulate the production of inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) causing inflammation and cell death. However, there are various compounds with direct or indirect antioxidant activity that have been used to reduce ROS accumulation in animal models and humans. In this review, we report on the physiological and pathophysiological role of ROS in the retina with a special focus on the vascular system. Moreover, we present therapeutic approaches for individual retinal diseases targeting retinal signaling pathways involving ROS.

The effect of Rheum ribes L. on oxidative stress in diabetic rats

Objectives Rheum ribes L. is a perennial plant that belongs to the family of Polygonaceae, which is often used in traditional therapy because it possesses many bioactivities, such as antioxidant and antibacterial ones. Here we examined the effect of different R. ribes L. extracts on oxidative stress in experimental diabetic rats. Methods Thirty-six rats were divided into six groups as follows: group I, control group; group II, diabetic rats; group III, diabetic rats treated with the aqueous extract of R. ribes L. by gavage at 50 mg/kg for 15 days; group IV, diabetic rats treated by gavage with the ethanolic extract of R. ribes L. at 50 mg/kg for 15 days; group V, nondiabetic rats treated by gavage with the aqueous extract of R. ribes L. at 50 mg/kg for 15 days; group VI, nondiabetic rats treated by gavage with the ethanol extract of R. ribes L. at 50 mg/kg for 15 days. After 15 days, the animals were sacrificed and the liver and kidney tissues of each animal were isolated. Superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) activities in the tissue samples were measured, and histopathologic examination was carried out. Results R. ribes L. was effective in reducing the oxidative stress and increasing the levels of the antioxidant enzymes. Increased levels of MDA and decreased levels of SOD, CAT and GSH-Px were observed in both the liver and kidney tissues in group II. Decreased levels of MDA and increased levels of SOD, CAT and GSH-Px were observed in group III compared with group II. In group IV, decreased levels of MDA and increased levels of SOD, CAT and GSH-Px were observed in comparison with group II. Conclusions Diabetes increases oxidative stress and causes a decrease in antioxidant enzyme levels. Both aqueous and ethanolic extracts of R. ribes L. decrease oxidative stress activity and increase the levels of antioxidant enzymes. The ethanol extract of R. ribes L. has a higher antioxidant effect than the aqueous extract.

Detecting hemodynamic changes in the foot vessels of diabetic patients by photoacoustic tomography

Limb perfusion monitoring is critical for diabetes mellitus (DM) patients as they are vulnerable to vascular complications due to prolonged hyperglycemia. However, current clinical approaches are ineffective in vascular imaging and in assessing vascular function in lower limbs. In this work, a concave ultrasound transducer array-based photoacoustic tomography (PAT) system was used to image the foot dorsal section of a subject, and a total of seven DM patients and seven healthy volunteers were enrolled in this study. Hemodynamic changes in foot vessels during vascular occlusion as well as oxygen saturation (SO₂ ) in rest were analyzed for both groups. The results obtained showed that DM patients have a unique peripheral hemodynamic response to occlusion and a lower level SO₂ , compared to that for healthy subjects. This suggests that PAT has the potential to detect vascular dysfunction in DM patients and to measure the effect of treatment.

Cellular Based Strategies for Microvascular Engineering

Vascularization is a major hurdle in complex tissue and organ engineering. Tissues greater than 200 μm in diameter cannot rely on simple diffusion to obtain nutrients and remove waste. Therefore, an integrated vascular network is required for clinical translation of engineered tissues. Microvessels have been described as <150 μm in diameter, but clinically they are defined as <1 mm. With new advances in super microsurgery, vessels less than 1 mm can be anastomosed to the recipient circulation. However, this technical advancement still relies on the creation of a stable engineered microcirculation that is amenable to surgical manipulation and is readily perfusable. Microvascular engineering lays on the crossroads of microfabrication, microfluidics, and tissue engineering strategies that utilize various cellular constituents. Early research focused on vascularization by co-culture and cellular interactions, with the addition of angiogenic growth factors to promote vascular growth. Since then, multiple strategies have been utilized taking advantage of innovations in additive manufacturing, biomaterials, and cell biology. However, the anatomy and dynamics of native blood vessels has not been consistently replicated. Inconsistent results can be partially attributed to cell sourcing which remains an enigma for microvascular engineering. Variations of endothelial cells, endothelial progenitor cells, and stem cells have all been used for microvascular network fabrication along with various mural cells. As each source offers advantages and disadvantages, there continues to be a lack of consensus. Furthermore, discord may be attributed to incomplete understanding about cell isolation and characterization without considering the microvascular architecture of the desired tissue/organ.

Association between C reactive protein and microvascular and macrovascular dysfunction in sub-Saharan Africans with and without diabetes: the RODAM study

INTRODUCTION

Although inflammation assessed by elevated C reactive protein (CRP) concentration is known to be associated with risk of cardiovascular disease, its association with microvascular and macrovascular dysfunction in diabetes and non-diabetes remains unclear. We examined the association between CRP and diabetes and associated microvascular and macrovascular dysfunction in sub-Saharan Africans with and without diabetes.

RESEARCH DESIGN AND METHODS

Cross-sectional analyses of baseline data from the multicenter RODAM study (Research on Obesity and Diabetes among African Migrants) including 5248 Ghanaians (583 with diabetes, 4665 without diabetes) aged 25-70 years were done. Logistic regression analyses were used to examine the associations between CRP Z-scores and diabetes and microvascular (nephropathy) and macrovascular (peripheral artery disease (PAD)) dysfunction, with adjustments for age, sex, site of residence, smoking, body mass index, systolic blood pressure, and low-density lipoprotein cholesterol.

RESULTS

In the fully adjusted models, higher CRP concentration was significantly associated with diabetes (adjusted OR 1.13; 95% CI 1.05 to 1.21, p=0.002). In participants with diabetes, higher CRP concentration was associated with PAD (1.19; 1.03 to 1.41, p=0.046) but not nephropathy (1.13; 0.97 to 1.31, p=0.120). Among participants without diabetes, higher CRP concentration was associated with higher odds of PAD (1.10; 1.01 to 1.21, p=0.029) and nephropathy (1.12; 1.04 to 1.22, p=0.004).

CONCLUSIONS

In this study, higher CRP concentration was associated with higher odds of diabetes in sub-Saharan Africans. Also, higher CRP concentration was associated with higher odds of nephropathy and PAD in non-diabetes and higher odds of PAD in diabetes. CRP may be an important marker for assessment of risk of diabetes and risk for PAD and nephropathy in sub-Saharan Africans with and without diabetes.

Obesity, clinical, and genetic predictors for glycemic progression in Chinese patients with type 2 diabetes: A cohort study using the Hong Kong Diabetes Register and Hong Kong Diabetes Biobank

BACKGROUND

Type 2 diabetes (T2D) is a progressive disease whereby there is often deterioration in glucose control despite escalation in treatment. There is significant heterogeneity to this progression of glycemia after onset of diabetes, yet the factors that influence glycemic progression are not well understood. Given the tremendous burden of diabetes in the Chinese population, and limited knowledge on factors that influence glycemia, we aim to identify the clinical and genetic predictors for glycemic progression in Chinese patients with T2D.

METHODS AND FINDINGS

In 1995-2007, 7,091 insulin-naïve Chinese patients (mean age 56.8 ± 13.3 [SD] years; mean age of T2D onset 51.1 ± 12.7 years; 47% men; 28.4% current or ex-smokers; median duration of diabetes 4 [IQR: 1-9] years; mean HbA1c 7.4% ± 1.7%; mean body mass index [BMI] 25.3 ± 4.0 kg/m2) were followed prospectively in the Hong Kong Diabetes Register. We examined associations of BMI and other clinical and genetic factors with glycemic progression defined as requirement of continuous insulin treatment, or 2 consecutive HbA1c ≥8.5% while on ≥2 oral glucose-lowering drugs (OGLDs), with validation in another multicenter cohort of Hong Kong Diabetes Biobank. During a median follow-up period of 8.8 (IQR: 4.8-13.3) years, incidence of glycemic progression was 48.0 (95% confidence interval [CI] 46.3-49.8) per 1,000 person-years with 2,519 patients started on insulin. Among the latter, 33.2% had a lag period of 1.3 years before insulin was initiated. Risk of progression was associated with extremes of BMI and high HbA1c. On multivariate Cox analysis, early age at diagnosis, microvascular complications, high triglyceride levels, and tobacco use were additional independent predictors for glycemic progression. A polygenic risk score (PRS) including 123 known risk variants for T2D also predicted rapid progression to insulin therapy (hazard ratio [HR]: 1.07 [95% CI 1.03-1.12] per SD; P = 0.001), with validation in the replication cohort (HR: 1.24 [95% CI 1.06-1.46] per SD; P = 0.008). A PRS using 63 BMI-related variants predicted BMI (beta [SE] = 0.312 [0.057] per SD; P = 5.84 × 10-8) but not glycemic progression (HR: 1.01 [95% CI 0.96-1.05] per SD; P = 0.747). Limitations of this study include potential misdiagnosis of T2D and lack of detailed data of drug use during follow-up in the replication cohort.

CONCLUSIONS

Our results show that approximately 5% of patients with T2D failed OGLDs annually in this clinic-based cohort. The independent associations of modifiable and genetic risk factors allow more precise identification of high-risk patients for early intensive control of multiple risk factors to prevent glycemic progression.

Intelligent therapeutic decision support for 30 days readmission of diabetic patients with different comorbidities

The significance of medication therapy in managing comorbid diabetes is vital for maintaining the overall wellness of patients and reducing the cost of healthcare. Thus, using appropriate medication or medication combinations will be necessary for improved person-centred care and reduce complications associated with diagnosis and treatment. This study explains an intelligent decision support framework for managing 30 days unplanned readmission (30_URD) of comorbid diabetes using the Random Forest (RF) algorithm and Bayesian Network (BN) model. After the analysis of the medical records of 101,756 de-identified diabetic patients treated with 21 medications for 28 comorbidity combinations, the optimal medications for minimizing the likelihood of early readmissions were determined. This approach can help for identifying and managing most vulnerable patients thereby giving room to enhance post-discharge monitoring through clinical specialist supports to build critical-self management skills that will minimize the cost of diabetes care.

Loss of association between HbA1c and vascular disease in older adults with type 1 diabetes

Aims

Robust evidence supports intensive glucose control in those with recently diagnosed type 1 diabetes to reduce the risk of developing micro- and macrovascular complications. Data to support longitudinal glycaemic targets is lacking. We aimed to explore if longer duration of diabetes and greater age might reduce the impact of glycaemia on the risk of vascular complications.

Research and design methods

Data for adults age 20 years or more, was extracted from a clinical database of people with type 1 diabetes cared for at a London teaching hospital. The presence or absence of micro- and macro-vascular complications was recorded. Multivariable logistic regression analysis was performed using HbA1c as independent variable, diabetes duration and age as continuous variable and obesity, hypertension, hypercholesterolaemia, low HDL cholesterol and hypertriglyceridaemia as categorical variables.

Results

Data from 495 patients was used. HbA1c above 60 mmol/mol (7.6%) was associated with increased microvascular complications in patients aged 20–44 years, independent of age and duration of diabetes. In older people with T1DM duration of diabetes was the major risk factor.

Conclusions

Our study suggests that increased age and greater duration of diabetes reduce the impact of glycaemia on the risk of vascular complications. Intensive blood glucose management in patients aged ≥45 years may have limited benefits in terms of reducing the risk of complications although this does not dismiss the benefits of good glycaemic control in older people with T1DM.

Triglyceride Glucose Index and Prognosis of Patients With Ischemic Stroke

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

Korean red ginseng attenuates hyperglycemia-induced renal inflammation and fibrosis via accelerated autophagy and protects against diabetic kidney disease

ETHNOPHARMACOLOGICAL RELEVANCE

Panax ginseng C.A. Mey. (Korean ginseng) has been widely used in traditional medicine to treat diabetes mellitus for thousands of years. It also plays a key role in health maintenance owing to its anti-oxidant and anti-fatigue properties, and is quite popular as a dietary supplement.

AIM OF THE STUDY

This study was designed to offer a complementary and alternative medicine to manage the diabetic kidney disease (DKD), which causes long-term damage to the renal structure. We also investigated the regulation of the autophagy mechanism, which is the underlying the pathogenesis of DKD.

MATERIALS AND METHODS

The effect of Korean red ginseng (KRG) on DKD was evaluated using human kidney proximal tubular cells and streptozotocin (STZ)-treated Sprague-Dawley rat models. In vitro experiments were conducted to evaluate the proteins related to fibrosis and autophagy. This was followed by in vivo experiments involving rats treated with single intraperitoneal administration of STZ (60 mg/kg) and then with KRG solution orally for 4 weeks. Proteins related to renal injury, fibrosis, and autophagy were determined by immunoblotting. Hematoxylin and eosin (H&E), Periodic acid-Schiff (PAS), Sirius red, and immunostaining were processed for histological studies.

RESULTS

KRG diminished the levels of metabolic measurements and blood parameters. Western blotting showed a decreased expression of proteins, such as TGF-β1, KIM1, and AGE, which are responsible for renal inflammation, injury, and fibrosis. Histological studies also supported these results and revealed that the KRG-treated groups recovered from renal injury and fibrosis. Furthermore, the autophagy marker, LC3, was upregulated, whereas p62 was downregulated. The levels of proteins related to the autophagy mechanism, such as ATG7, increased, while mammalian target of rapamycin (mTOR) decreased with the KRG treatment and exhibited accelerated autophagy compared to the STZ alone group.

CONCLUSIONS

KRG can suppress renal inflammation, injury, and fibrosis by blocking TGF-β1 activation and can induce cellular autophagy. Therefore, this study strongly suggests that KRG exhibits a renoprotective effect against the STZ-induced DKD.

NLRP3 inflammasome drives inflammation in high fructose fed diabetic rat liver: Effect of resveratrol and metformin

AIMS

To unravel the underlying mechanism of hepatic inflammation during type 2 diabetes (T2DM), we established the diabetic rat model by feeding with high fructose diet for twenty weeks and studied the involvement of inflammasome in the liver of these rats.

MATERIALS AND METHODS

Male SD rats weighing 180-200 g were divided in four groups: 1) Control (Con group) rats were fed with corn starch diet, 2) diabetic (Dia group) rats were fed with 65% of fructose, 3) diabetic along with resveratrol (10 mg/kg/day); p.o. (Dia + Resv group) and 4) diabetic along with metformin (300 mg/kg/day); p.o. (Dia + Met group), for twenty weeks. We evaluated the establishment of T2DM in fructose fed rats and the effect of resveratrol and metformin treatment on different diabetic parameters in these rats. Further we investigated the role of NLRP3 inflammasome on T2DM induced liver inflammation and effect of resveratrol and metformin treatment on NLRP3 inflammasome driven inflammatory response.

KEY FINDINGS

Rats from Dia group; manifested insulin resistance, hyperinsulinemia, hyperglycemia, elevated uric acid along with hypertriglyceridemia after fructose feeding for twenty weeks. Mostly, above parameters were attenuated in resveratrol and metformin treated groups. Expression of NLRP3 inflammasome components in liver were increased in Dia group rats with elevated transcript levels of pro-inflammatory cytokines. Histopathological examination revealed increase in glycogen content and fibrosis in Dia group rats; which was considerably reduced with resveratrol and metformin treatment.

SIGNIFICANCE

Our study suggests that management of inflammation may be considered as an alternative approach to prevent liver tissue injury during chronic diabetic condition.

The role of apoptosis and autophagy in the insulin-enhancing activity of oxovanadium(IV) bipyridine complex in streptozotocin-induced diabetic mice

Metal-based therapies (e.g. Vanadium) possess an attractive proposition in medicinal treatment of diabetes mellitus. Defective insulin secretion can result from impaired β-cell function which is mediated by many process including apoptosis and autophagy. In this study. diabetes was induced by administration of streptozotocin then treatment was performed by vanadyl sulfate and [VO(bpy)₂ Cl] Cl.H₂O complex. Blood glucose level, AST, ALT, BUN, CR, TCHO, TG and total protein were determined in serum. MDA, NO, erythrocyte GSH and SOD were estimated. LC3 and Caspase 3 levels in pancreatic cells were assessed by flow cytometer. Histopathological investigation of pancreatic tissue was performed. Results of Diabetic group showed a significant increase in transaminases activities, TCHO, TG, MDA, NO and Caspase 3 levels and significant decrease in TP, GSH, SOD and LC3 levels. Oral administration of vanadium complex resulted in normoglycemia, significant increase in blood GSH, SOD, TP and LC3 levels, significant decrease in ALT, AST, BUN, TCHO, TG, MDA and NO and Caspase 3 levels. In addition, proliferative effect of complex prevents islet atrophy. From previous results, the insulin-enhancing effect induced by this complex indicated that this new complex can be a valuable candidate as insulin-enhancing and antioxidant compound than inorganic vanadyl sulfate.

The Combination Effect of Aspalathin and Phenylpyruvic Acid-2-O-β-D-glucoside from Rooibos against Hyperglycemia-Induced Cardiac Damage: An In Vitro Study

Recent evidence shows that rooibos compounds, aspalathin and phenylpyruvic acid-2-O-β-d-glucoside (PPAG), can independently protect cardiomyocytes from hyperglycemia-related reactive oxygen species (ROS). While aspalathin shows more potency by enhancing intracellular antioxidant defenses, PPAG acts more as an anti-apoptotic agent. Thus, to further understand the protective capabilities of these compounds against hyperglycemia-induced cardiac damage, their combinatory effect was investigated and compared to metformin. An in vitro model of H9c2 cardiomyocytes exposed to chronic glucose concentrations was employed to study the impact of such compounds on hyperglycemia-induced damage. Here, high glucose exposure impaired myocardial substrate utilization by abnormally enhancing free fatty acid oxidation while concomitantly suppressing glucose oxidation. This was paralleled by altered expression of genes involved in energy metabolism including acetyl-CoA carboxylase (ACC), 5′ AMP-activated protein kinase (AMPK), and peroxisome proliferator-activated receptor-alpha (PPARα). The combination treatment improved myocardial substrate metabolism, maintained mitochondrial membrane potential, and attenuated various markers for oxidative stress including nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity and glutathione content. It also showed a much-improved effect by ameliorating DNA damage when compared to metformin. The current study demonstrates that rooibos compounds offer unique cardioprotective properties against hyperglycemia-induced and potentially against diabetes-induced cardiac damage. These data also support further exploration of rooibos compounds to better assess the cardioprotective effects of different bioactive compound combinations.

Thirty-day experimental diabetes impairs contractility and increases fatigue resistance in rat diaphragm muscle associated with increased anti-oxidative activity

Diabetes mellitus is a metabolic disorder that can generate tissue damage through several pathways. Alteration and dysfunction of skeletal muscle are reported including respiratory muscles, which may compromise respiratory parameters in diabetic patients. We have aimed to evaluate the diaphragm muscle contractility, tissue remodeling, oxidative stress, and inflammatory parameters from 30 day streptozotocin-treated rats. The diaphragm contractility was assessed using isolated muscle, tissue remodeling using histology and zymography techniques, and tissue oxidative stress and inflammatory parameters by enzyme activity assay. Our data revealed in the diabetes mellitus group an increase in maximum tetanic force (4.82 ± 0.13 versus 4.24 ± 0.18 N/cm² (p = 0.015)) and fatigue resistance (139.16 ± 10.78 versus 62.25 ± 4.45 s (p < 0.001)), reduction of 35.4% in muscle trophism (p < 0.001), increase of 32.6% of collagen deposition (p = 0.007), reduction of 21.3% in N-acetylglucosaminidase activity (p < 0.001), and increase of 246.7% of catalase activity (p = 0.002) without changes in reactive oxygen species (p = 0.518) and tissue lipid peroxidation (p = 0.664). All observed changes are attributed to the poor glycemic control (471.20 ± 16.91 versus 80.00 ± 3.42 mg/dL (p < 0.001)), which caused defective tissue regeneration and increased catalase activity as a compensatory mechanism.

The impact of coenzyme Q10 on metabolic and cardiovascular disease profiles in diabetic patients: A systematic review and meta-analysis of randomized controlled trials

AIMS

Coenzyme Q10 (CoQ10) is well known for its beneficial effects in cardiovascular disease (CVD); however, reported evidence has not been precisely synthesized to better inform on its impact in protecting against cardiovascular-related complications in diabetic patients.

MATERIALS AND METHODOLOGY

The current meta-analysis included randomized controlled trials published in the past 5 years reporting on the effect of CoQ10 on metabolic and CVD-related risk profiles in individuals with diabetes or metabolic syndrome. We searched electronic databases such as MEDLINE, Cochrane Library, Scopus and EMBASE for eligible studies. In addition to assessing the risk of bias and quality of evidence, the random and fixed-effect models were used to calculate the standardized mean difference and 95% confidence intervals for metabolic parameters and CVD outcomes.

RESULTS

Overall, 12 studies met the inclusion criteria, enrolling a total of 650 patients. Although CoQ10 supplementation did not statistically affect all metabolic profiles measured, it significantly reduced CVD-risk-related indexes such as total cholesterol and low-density lipoprotein (LDL) levels in diabetic patients when compared to those on placebo [SMD = 0.13, 95% CI (0.03; 0.23), Chi2 = 43.62 and I 2 = 29%, P = .07].

CONCLUSIONS

The overall results demonstrated that supplementation with CoQ10 shows an enhanced potential to lower CVD risk in diabetic patients by reducing total cholesterol and LDL. Moreover, the beneficial effects of CoQ10 in lowering the CVD risk are associated with its ameliorative properties against oxidative stress and improving endothelial health.

Investigating the effect of some fluoroquinolones on C-reactive protein levels and ACh-Induced blood pressure reduction deviations after aging of diabetes in STZ-Induced diabetic wistar rats

The treatment of infections in diabetic patients by fluoroquinolone antibiotics is associated with a reduced risk of coronary artery disease, and may improve endothelium-derived hyperpolarizing factor (EDHF) efficacy. The inflammatory marker C-reactive protein (CRP) is an important predictor of cardiovascular events, and vascular endothelium dysfunction, which makes this marker a target for drug-based treatment. This study aims to investigate the relation between the treatment by fluoroquinolones with CRP plasma levels, as well as acetylecholine (ACh)-induced small conductance calcium-activated potassium channels (SKCa)-dependent blood pressure (BP) reduction deviations in wistar rats after inducing a type 2-like diabetes with aging state after four months of streptozotocin (STZ) injection. Experimental animals were divided into four groups, group 1: diabetic animals were treated with moxifloxacin (n = 15), group 2: diabetic animals were treated with levofloxacin (n = 15), group 3: diabetic control animals (n = 15), and group 4: non-diabetic control animals (n = 6). The levels of plasma CRP, as well as ACh-induced SKCa-dependent BP reduction deviations were compared four months after the development of diabetes, after that; two groups were treated with fluoroquinolones, four months after the treatment; CRP-plasma levels, as well as ACh-induced SKCa-dependent BP reduction deviations were also evaluated and compared for all groups. Sustained hyperglycemia after the induction of diabetes elevated CRP plasma levels, and reduced ACh-induced SKCa-dependent BP reduction, observed diabetes-induced variations were minimal in fluoroquinolones treated diabetic groups compared with diabetic control group, In conclusion, the treatment with fluoroquinolone antibiotics in diabetic wistars may be associated with a lowering in CRP levels progression, and improvement in SKCa vitality, which indicates the importance of treating infections in diabetics by fluoroquinolones to mitigate some vascular complications signs that lead to morbidity and mortality in diabetes.

Impact of Active Antihyperglycemic Components as Herbal Therapy for Preventive Health Care Management of Diabetes

Diabetes is a metabolic hyperglycemic condition that progressively develops, effect small and large sensory fibers in the affected population. It has various complications as hypertension, coronary artery disease, stroke, blindness, kidney disease as well as peripheral neuropathy. Sulfonylureas, thiazolidinediones, metformin, biguanidine, acarbose and insulin are commonly used drugs for diabetic patients, but these all have certain side effects. Even metformin, that is known as the miracle drug for diabetes has been found to be associated with side effects, as during treatment it involves complications with eyes, kidneys, peripheral nerves, heart and vasculature. In the present article, we hypothesize recent discoveries with respect to active ingredients from Indian medicinal plants i.e., polypeptide-p (protein analogue act as artificial insulin), charantin (a steroidal saponin), momordicin (an alkaloid) and osmotin (ubiquitous plant protein and animal analogue of human adeponectin) possessing anti-hyperglycemic potential for diabetes type II. Therefore, plants as herbal therapy have preventive care of hyperglycemia accompanied with healthy lifestyle which can provide significant decline in the incidences of diabetes in future.

Validated 60-Second General Foot Screen: A Pilot Trial and Guide to Diagnoses and Treatment

GENERAL PURPOSE

To provide information on a 60-second General Foot Screen to assist in the prevention and/or identification and management of common foot problems.

TARGET AUDIENCE

This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care.

LEARNING OBJECTIVES/OUTCOMES

After participating in this educational activity, the participant should be better able to:1. Use the 60-second General Foot Screen to assist healthcare professionals in the recognition of common foot problems.2. Identify risk factors, causes, and treatment of selected foot problems.

ABSTRACT

Foot health is important to overall patient health. Early diagnosis and treatment of diabetes, neuropathy, fungal foot infections, foot deformity, and vascular disease/lower leg edema can improve patient quality of life. One way to achieve this is effective screening. To this end, researchers piloted a validated 10-item screening tool to assess foot health on 120 patients; 74.17% had at least one positive abnormality, demonstrating the critical importance of these early findings. Only 25.83% of individuals had completely low-risk feet. This easy-to-use tool can assist healthcare professionals in the recognition and treatment of common foot problems. The article also outlines the early signs of disease by screening item and provides a guide to treatment to enable effective prevention and quality care.

Alpha-Glucosidase Inhibitor Voglibose Suppresses Azoxymethane-Induced Colonic Preneoplastic Lesions in Diabetic and Obese Mice

Type 2 diabetes mellitus and its related insulin resistance are known to increase the risk of cancer. Anti-diabetic agents can improve insulin resistance and may lead to the suppression of carcinogenesis. This study aimed to investigate the preventive effects of the alpha-glucosidase inhibitor voglibose on the development of azoxymethane-induced colorectal pre-neoplastic lesions in obese and diabetic C57BL/KsJ-db/db mice. The direct effects of voglibose on the proliferation of colorectal cancer cells were also evaluated. Mice were injected with azoxymethane to induce colorectal pre-malignancy and were then administered drinking water with or without voglibose. At the end of the study, the administration of voglibose significantly suppressed the development of colorectal neoplastic lesions. In voglibose-treated mice, serum glucose levels, oxidative stress, as well as mRNA expression of the insulin-like growth factor-1 in the colon mucosa, were reduced. The proliferation of human colorectal cancer cells was not altered by voglibose. These results suggested that voglibose suppressed colorectal carcinogenesis in a diabetes- and obesity-related colorectal cancer model, presumably by improving inflammation via the reduction of oxidative stress and suppressing of the insulin-like growth factor/insulin-like growth factor-1 receptor axis in the colonic mucosa.

Considerations for Using the Vasculature as a Coordinate System to Map All the Cells in the Human Body

Several ongoing international efforts are developing methods of localizing single cells within organs or mapping the entire human body at the single cell level, including the Chan Zuckerberg Initiative's Human Cell Atlas (HCA), and the Knut and Allice Wallenberg Foundation's Human Protein Atlas (HPA), and the National Institutes of Health's Human BioMolecular Atlas Program (HuBMAP). Their goals are to understand cell specialization, interactions, spatial organization in their natural context, and ultimately the function of every cell within the body. In the same way that the Human Genome Project had to assemble sequence data from different people to construct a complete sequence, multiple centers around the world are collecting tissue specimens from diverse populations that vary in age, race, sex, and body size. A challenge will be combining these heterogeneous tissue samples into a 3D reference map that will enable multiscale, multidimensional Google Maps-like exploration of the human body. Key to making alignment of tissue samples work is identifying and using a coordinate system called a Common Coordinate Framework (CCF), which defines the positions, or "addresses," in a reference body, from whole organs down to functional tissue units and individual cells. In this perspective, we examine the concept of a CCF based on the vasculature and describe why it would be an attractive choice for mapping the human body.

Protective effects of losartan on some type 2 diabetes mellitus-induced complications in Wistar and spontaneously hypertensive rats

Diabetes mellitus type 2 (T2DM) is characterized by resistance of insulin receptors and/or inadequate insulin secretion resulting in metabolic and structural complications including vascular diseases, arterial hypertension and different behavioral alterations. We aimed to study the effects of the antihypertensive angiotensin AT1 receptor antagonist losartan on the T2DM-induced changes of exploratory behavior, anxiety, nociception and short term memory in normotensive Wistar and spontaneously hypertensive rats (SHRs). The experimental model of T2DM induced by a combination of high fat diet and streptozotocin, decreased exploratory activity and increased the level of carbonylated proteins in selected brain structures in both strains; as well it increased corticosterone level, pain threshold, anxiety-like behavior, and decline short term memory only in SHRs. Losartan treatment alleviated some of the T2DM- induced metabolic complications, abolished the T2DM-induced hypo activity, and normalized the corticosterone level, carbonylated proteins in brain, nociception and memory. Losartan did not exert effect on the anxiety behavior in both strains. We showed that T2DM exerted more pronounced negative effects on the rats with comorbid hypertension as compared to normotensive rats. Overall effects on the studied behavioral parameters are related to decreased exploration of the new environment, increased anxiety-like behavior, and decline in short-term memory. The systemic sub-chronic treatment with an angiotensin AT1 receptor antagonist losartan ameliorated most of these complications.

Dose-Response Effects of Exercise on Glucose-Lowering Medications for Type 2 Diabetes: A Secondary Analysis of a Randomized Clinical Trial

OBJECTIVE

To investigate whether a dose-response relationship exists between volume of exercise and discontinuation of glucose-lowering medication treatment in patients with type 2 diabetes.

PATIENTS AND METHODS

Secondary analyses of a randomized controlled exercise-based lifestyle intervention trial (April 29, 2015 to August 17, 2016). Patients with non-insulin-dependent type 2 diabetes were randomly assigned to an intensive lifestyle intervention (U-TURN) or standard-care group. Both groups received lifestyle advice and objective target-driven medical regulation. Additionally, the U-TURN group received supervised exercise and individualized dietary counseling. Of the 98 randomly assigned participants, 92 were included in the analysis (U-TURN, n=61, standard care, n=31). Participants in the U-TURN group were stratified into tertiles based on accumulated volumes of exercise completed during the 1-year intervention.

RESULTS

Median exercise levels of 178 (interquartile range [IQR], 121-213; lower tertile), 296 (IQR, 261-310; intermediate tertile), and 380 minutes per week (IQR, 355-446; upper tertile) were associated with higher odds of discontinuing treatment with glucose-lowering medication, with corresponding odds ratios of 12.1 (95% CI, 1.2-119; number needed to treat: 4), 30.2 (95% CI, 2.9-318.5; 3), and 34.4 (95% CI, 4.1-290.1; 2), respectively, when comparing with standard care. Cardiovascular risk factors such as glycated hemoglobin A_1c levels, fitness, 2-hour glucose levels, and triglyceride levels were improved significantly in the intermediate and upper tertiles, but not the lower tertile, compared with the standard-care group.

CONCLUSION

Exercise volume is associated with discontinuation of glucose-lowering medication treatment in a dose-dependent manner, as are important cardiovascular risk factors in well-treated participants with type 2 diabetes and disease duration less than 10 years. Further studies are needed to support these findings.

STUDY REGISTRATION

ClinicalTrials.gov registration (NCT02417012).

Comparison of Efficacy of Nortriptyline Versus Transcutaneous Electrical Nerve Stimulation on Painful Peripheral Neuropathy in Patients with Diabetes

Background and aims: Diabetic peripheral neuropathic pain (DPNP) is one of the most common complications of diabetes and is difficult to treat. Existing treatments are often inadequate at controlling pain and limited by side-effects and drug tolerance. This study assessed the efficacy of nortriptyline versus Transcutaneous Electrical Nerve Stimulation (TENS) in patients with DPNP.

Material and method: This is a randomized clinical trial study conducted on 39 patients with DPNP referring to Golestan Hospital in Ahvaz in 2017. Patients were randomly treated with TENS (18 sessions, each session 30 minutes; n=20) or nortriptyline (25 to 75 mg, once daily; n=19) for 6 weeks. Patients were evaluated for side effects and pain relief using visual analog scale (VAS).

Results: There was a significant improvement in pain with both treatments compared with baseline (p˂0.001). The patients in nortriptyline group experienced more pain relief (7.21±1.51 to 0.84±1.34) than the TENS group (7.6±1.47 to 2.75 ±2.43) (P=0.001). The 50% pain relief was observed in 14 patients (73%) in nortriptyline group, 6 patients (30%) in TENS group. Moreover, the side effects were seen in 15% of TENS and 55% of patients in nortriptyline groups (P=0.019).

Conclusion: Both TENS and nortriptyline were effective and safe in the management of DPNP. But nortriptyline showed a better performance on pain relief.

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

BACKGROUND AND AIMS

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

METHODS AND RESULTS

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

CONCLUSION

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

Cross-cultural validation of the Retinopathy Treatment Satisfaction Questionnaire status version (RetTSQs) in Serbian community: a cross-sectional study

OBJECTIVE

Cross-cultural translation and validation of the Serbian version of the Retinopathy Treatment Satisfaction Questionnaire status version (RetTSQs).

DESIGN

Cross-sectional study.

SETTINGS

The study was conducted between June 2017 and June 2018 at tertiary care centre in Serbia, Belgrade.

PARTICIPANTS

A total of 101 patients with diabetic retinopathy (DR) were included. All subjects were evaluated in two consecutive visits, the first during the initial contact to the clinic, while the second 4-6 weeks later.

MAIN OUTCOME MEASURES

Validation of Serbian version of the RetTSQs was the major outcome.

RESULTS

Cronbach alpha coefficient of the subscales ranged from 0.783 (positive scale) to 0.811 (negative scale) and for all domains it was excellent at α=0.829. The intraclass correlation coefficient was greater than 0.8 for all of the subscales. Univariable analyses revealed that age, gender, education, marital status and working status did not affect the RetTSQ scores, whereas participants with non-proliferative DR reported significantly higher treatment satisfaction (TS) than those with proliferative retinopathy (p=0.001). The group who received laser treatment scored significantly lower than the group without it (p=0.004) regardless of type of performed laser. Positive and statistically significant correlations were found between the RetTSQ score and most of the National Eye Institute Visual Functioning Questionnaire-25 subscales.

CONCLUSION

Translated Serbian adaptation of the RetTSQs showed adequate psychometric characteristics as an acceptable, reliable and valid questionnaire. It was well understood by Serbian diabetic patients and it promises to be used in daily clinical work as an instrument for the assessment of TS for patients with DR.

Context-Dependent Regulation of Nrf2/ARE Axis on Vascular Cell Function during Hyperglycemic Condition

Diabetes mellitus is associated with an increased risk of micro and macrovascular complications. During hyperglycemic conditions, endothelial cells and vascular smooth muscle cells are exquisitely sensitive to high glucose. This high glucose-induced sustained reactive oxygen species production leads to redox imbalance, which is associated with endothelial dysfunction and vascular wall remodeling. Nrf2, a redox-regulated transcription factor plays a key role in the antioxidant response element (ARE)-mediated expression of antioxidant genes. Although accumulating data indicate the molecular mechanisms underpinning the Nrf2 regulated redox balance, understanding the influence of the Nrf2/ARE axis during hyperglycemic condition on vascular cells is paramount. This review focuses on the context-dependent role of Nrf2/ARE signaling on vascular endothelial and smooth muscle cell function during hyperglycemic conditions. This review also highlights improving the Nrf2 system in vascular tissues, which could be a potential therapeutic strategy for vascular dysfunction.

Clinical Associations of Thyroid Hormone Levels with the Risk of Atherosclerosis in Euthyroid Type 2 Diabetic Patients in Central China

BACKGROUND

Thyroid function is associated with the etiology and pathogenesis of type 2 diabetes (T2D) and potentially contributes to the development of the complications of T2D. The association of thyroid hormones with atherosclerosis in euthyroid T2D patients is not clear.

PURPOSE

To investigate the association of thyroid hormone levels with the risk of developing atherosclerosis in euthyroid T2D patients in Central China.

METHODS

This cross-sectional study recruited 910 euthyroid T2D patients from Henan Provincial People's Hospital, China. Association among hemoglobin A1c (HbA1c), thyroid hormones, and the prevalence of atherosclerosis was assessed by multivariable Cox models after adjusting for covariates including age, BMI, duration of T2D, smoking status, SBP, TC, family history of T2D, and medications on hyperlipidemia.

RESULTS

Among all 910 subjects, 373 were diagnosed with atherosclerosis. There were 523 females and 387 males included in this study. The mean age was 51.9 years. The average BMI was 25.3 kg/m². Low-normal serum-free triiodothyronine (FT3) levels (3.50-4.17 pmol/L) were associated with a high prevalence of atherosclerosis. Comparing with low-normal FT3, the prevalence ratio in patients with mid- (4.17-4.83 pmol/L) and high-normal FT3 level (4.83-6.50 pmol/L) is 0.74 (95% CI 0.56 to 0.97, p=0.029) and 0.63 (95% CI 0.46 to 0.87, p=0.005) after adjusting for covariates. High level of free thyroxine (FT4) also had decreased risk for atherosclerosis. Thyroid-stimulating hormone (TSH) and FT3 to FT4 ratio did not show significant association with the development of atherosclerosis.

CONCLUSION

T2D patients with low but clinically normal FT3 level are more likely to develop macrovascular complications comparing with those with mid- and high-normal FT3 level.

Growth of Diabetes Research in United Arab Emirates: Current and Future Perspectives

BACKGROUND

Diabetes mellitus (DM) is one of the most prevalent metabolic diseases in the UAE. During the last two decades, the United Arab Emirates (UAE) has experienced tremendous development in all fields including DM research. The present study sheds light on the growth in DM research in UAE and represents a guide for DM researchers to create more focused future directions in DM research.

OBJECTIVES

The main objective of the present study is to investigate and document the changes that occurred in DM research in the UAE over the last two decades.

METHODS

Several research databases were reviewed and all the articles that involved any form of DM research within the UAE were selected. Inclusion criteria were: (i) Research studies related to DM and conducted by institutions based in UAE (ii) Research studies related to DM and conducted in the population of UAE and (iii) Research articles related to DM and the authors (principal investigators or co-investigators) are from UAE.

RESULTS

Between the years of 1996 and 2000, there was an average of 6.4 articles about DM being published per year. This pattern changed dramatically between years 2011 to 2015 where an average of 22.8 articles were being published. In addition, a significant increase was noticed in the year 2015 with 42 articles published per year. It was also found that 46.8% articles involved clinical study, 12.1% were basic research, 17.5% cross-sectional studies, 8.91% reviews, 8.2% were cohort and all the other types of research represented about 5.58%.

CONCLUSION

Significant progress has been noticed in DM research in the UAE during the last two decades. Based on the findings of the present study, more focus should be given to the case reports and clinical trials.

LIN28B Impairs the Transition of hESC-Derived β Cells from the Juvenile to Adult State

Differentiation of human embryonic stem cells into pancreatic β cells holds great promise for the treatment of diabetes. Recent advances have led to the production of glucose-responsive insulin-secreting cells in vitro, but resulting cells remain less mature than their adult primary β cell counterparts. The barrier(s) to in vitro β cell maturation are unclear. Here, we evaluated a potential role for microRNAs. MicroRNA profiling showed high expression of let-7 family microRNAs in vivo, but not in in vitro differentiated β cells. Reduced levels of let-7 in vitro were associated with increased levels of the RNA binding protein LIN28B, a negative regulator of let-7 biogenesis. Ablation of LIN28B during human embryonic stem cell (hESC) differentiation toward β cells led to a more mature glucose-stimulated insulin secretion profile and the suppression of juvenile-specific genes. However, let-7 overexpression had little effect. These results uncover LIN28B as a modulator of β cell maturation in vitro.

Triterpene derivative improves the renal function of streptozotocin-induced diabetic rats: a follow-up study on maslinic acid

Introduction: Reports indicate that oral administration of plant-derived maslinic acid (MA) exhibits hypoglycemic and renoprotective effects in streptozotocin (STZ)-induced diabetic rats. Challenges with triterpenes such as MA include low bioavailabilty which affects treatment efficacy in experimental animals. The goal of this study was to synthesize the MA derivative phenylhydrazine (PH-MA) in an effort to improve the efficacy of MA.

Methods: Separate groups of non-diabetic and STZ-induced diabetic rats (n = 6) were anesthetized and the jugular vein cannulated for the infusion of 0.077 M NaCl at 9 mL/h. The bladder was catheterized for collection the urine samples every 30 min. After 30.5 h equilibration period, consecutive 30 min urine collections were made over the subsequent 4 h of 1 h control, 1.5 h treatment, and 1.5 h recovery periods. PH-MA (22 µg/h) and MA (90 µg/h) were added during the treatment periods for analysis of proximal tubular Na⁺ handling, plasma aldosterone and arginine vasopressin in male Sprague-Dawley rats.

Results: Intravenous infusion of PH-MA (22 µg/h) and MA (90 µg/h) significantly (p ˂ .05) increased Na⁺ output, fractional excretion of Na⁺ (FENa) and lithium (FELi). Interestingly, like MA, PH-MA significantly (p ˂ .05) increased glomerular filtration rate (GFR) over the treatment period and decreased plasma aldosterone levels. Our findings indicate that PH-MA inhibited sodium reabsorption in the proximal and distal tubule as shown by increased FENa and low plasma aldosterone levels, respectively.

Conclusions: PH-MA is, therefore, a promising multitarget antidiabetic agent that may ameliorate kidney function of diabetic patients at a dose four times lower than the parent compound (MA).

Heparanase upregulation from adipocyte associates with inflammation and endothelial injury in diabetic condition

Background

Diabetes Mellitus (DM) is one of the metabolic diseases which leads to fatty tissue injury, and consequently inducing lipotoxicity and cellular senescence. This condition contributes to endothelial dysfunction with chronic inflammation and organ damage. Heparanase which has a role in disrupting endothelial surface layer (glycocalyx) may promote endothelial Nitric oxide synthase (eNOS) reduction and inflammation. However, its relationship with DM and organ injury has not been fully elucidated yet. This study aimed to determine how heparanase from fatty tissue may contribute to endothelial dysfunction and inflammation in patients with hyperglycemia and in a hyperglycemia model in rats.

Methods

This population study with a cross-sectional design was conducted with 28 subjects without diagnosis and medication of DM. Fasting blood glucose levels, lipid profile, heparanase protein, MCP-1 protein and HbA1c were quantified. In vivo study was performed with a diabetic model in Wistar rats induced with streptozotocin 60 mg/kg body weight by single intraperitoneal injection. Rats were euthanized after 1 month (DM1 group, n = 6), 2 months (DM2 group, n = 6) and 4 months (DM4 group, n = 6). White Adipose Tissue (WAT) was harvested from visceral fat. Real Time and Reverse Transcriptase-PCR (RT-PCR) was done to quantify expressions of heparanase, MCP-1, eNOS, IL-6 and p-16 (senescence). Immunostaining was performed to localize MCP-1 and macrophage (CD68). Western blot tests were used to examine eNOS, MCP-1 and heparanase protein expression.

Results

This study revealed associations between blood glucose levels with higher HbA1c, LDL, cholesterol, heparanase and MCP-1. The in vivo study also revealed lipid levels as the source of Heparanase and MCP-1 mRNA and protein expressions. This finding was associated with inflammation, cellular senescence and macrophage infiltration in fat tissue based on immunostaining and qRT-PCR analysis. RT-PCR revealed significantly lower expression of eNOS and higher expression of IL-6 in DM groups compared to the control group.

Conclusion

Heparanase upregulation in fat tissue was associated with endothelial injury and inflammation in hyperglycemia conditions.

Alpha-mangostin decreased cellular senescence in human umbilical vein endothelial cells

BACKGROUND

The hyperglycemic condition in diabetes induces cellular senescence in vascular endothelial cells and causes cardiovascular complications. Alpha-mangostin is a xanthone found in Garcinia mangostana, and has shown protective effects in metabolic syndrome.

OBJECTIVE

In this study, the anti-senescence effects of alpha-mangostin in the hyperglycemic condition are investigated.

METHODS

HUVECs were incubated with high glucose for 6 days and co-treated by metformin or alpha-mangostin. After 6 days, cell viability, reactive oxygen species, the percentage of senescent cells, secretory interleukin-6, and the expression of SIRT1, AMPK, p53 and p21 were measured.

RESULTS

High glucose (60 mM) significantly decreased cellular viability and increased reactive oxygen species and cellular senescence through the reduction of senescence-associated β-galactosidase activity. Moreover, high glucose increased the protein levels of p53, acetyl-p53 and p21. The protein levels of SIRT1 and total AMPK were decreased by high glucose. High glucose increased the secretion of IL-6. Alpha-mangostin (1.25 μM) and metformin (50 μM) reversed the toxic effects of high glucose in HUVECs.

CONCLUSION

These results show that alpha-mangostin, similar to metformin, has anti-senescence effects in high-glucose conditions, which is probably due to its antioxidant activity through the SIRT1 pathway. Alpha-mangostin has previously shown anti-inflammatory effects and metabolic status improvement in animal and clinical studies. Therefore, this natural agent can be considered as a supplement to prevent vascular complications caused by high glucose in patients with diabetes. Graphical abstract.

Role of the Wnt signalling pathway in the development of endothelial disorders in response to hyperglycaemia

INTRODUCTION

Diabetes mellitus (DM) is the most common metabolic disease. A WHO report from 2016 indicates that 422 million people worldwide suffer from DM or hyperglycaemia because of impaired glucose metabolism. Chronic hyperglycaemia leads to micro- and macrovessel damage, which may result in life-threatening complications. The Wnt pathway regulates cell proliferation and survival by modulating the expression of genes that control cell differentiation. Three linked Wnt pathways have been discovered thus far: a β-catenin-dependent pathway and two pathways independent of β-catenin - the planar cell polarity pathway and calcium-dependent pathway. The Wnt pathway regulates genes associated with inflammation, cell cycle, angiogenesis, fibrinolysis and other molecular processes.

AREAS COVERED

This review presents the current state of knowledge regarding the contribution of the Wnt pathway to endothelial ageing under hyperglycaemic conditions and provides new insights into the molecular basis of diabetic endothelial dysfunction.

CONCLUSION

The β-catenin-dependent pathway is a potential target in the prophylaxis and treatment of early-stage diabetes-related vascular complications. However, the underlying molecular mechanisms remain largely undetermined and require further investigation.

The effect of acute cocoa flavanol intake on the BOLD response and cognitive function in type 1 diabetes: a randomized, placebo-controlled, double-blinded cross-over pilot study

RATIONALE

Type 1 diabetes (T1D), a chronic autoimmune disease, can result in cognitive dysfunction and is associated with vascular dysfunction. Cocoa flavanols (CFs) can stimulate nitric oxide-dependent vasodilation, resulting in enhanced hemodynamic responses and better cognitive function.

OBJECTIVES

To investigate whether acute CF supplementation can improve cognitive function and hemodynamic responses in T1D.

METHODS

In this randomized, double-blinded, cross-over pilot study, 11 patients with T1D and their healthy matched controls consumed CF (900 mg CF) and placebo (15 mg CF) 2 h before a flanker test. fMRI was used to measure blood oxygen level-dependent (BOLD) response during the cognitive test. Repeated measure ANOVAs were used to test the effects of CF and T1D on BOLD response and cognitive performance.

RESULTS

CF improved reaction time on the flanker test and increased the BOLD response in the supramarginal gyrus parietal lobe and inferior frontal gyrus, compared to placebo, in both groups. In patients with T1D, cognitive performance was not deteriorated while the BOLD response was smaller in T1D compared to healthy controls in the subgyral temporal lobe and the cerebellum.

CONCLUSIONS

Acute CF intake improved reaction time on the flanker test and increased the BOLD response in the activated brain areas in patients with T1D and their matched controls.

Long non-coding RNA GAPLINC promotes angiogenesis by regulating miR-211 under hypoxia in human umbilical vein endothelial cells

In this study, we investigated the role of a long non-coding RNA GAPLINC in angiogenesis using human umbilical vein endothelial cells (HUVEC). We found that hypoxia and hypoxia-inducible factor 1α (HIF-1α) increased the expression of GAPLINC in HUVEC cells. Moreover, GAPLINC overexpression down-regulated miR-211 and up-regulated Bcl2 protein expression. Further rescue experiments confirmed that hypoxia directly increased GAPLINC expression. GAPLINC overexpression also increased cell migration and vessel formation which promoted angiogenesis, and these changes were attributed to the increased expression of vascular endothelial growth factor receptors (VEGFR) and delta-like canonical notch ligand 4 (DLL4) receptors. Finally, we demonstrated that GAPLINC promotes vessel formation and migration by regulating MAPK and NF-kB signalling pathways. Taken together, these findings comprehensively demonstrate that overexpression of GAPLINC increases HUVEC cells angiogenesis under hypoxia condition suggesting that GAPLINC can be a potential target for critical limb ischaemia (CLI) treatment.

Anti-diabetic effect of -D-mannuronic acid (M2000) as a novel NSAID with immunosuppressive property on insulin production, blood glucose, and inflammatory markers in the experimental diabetes model

This research aimed to evaluate the anti-diabetic effects of β-d-mannuronic acid (M2000) on blood glucose, insulin production, and inflammatory markers in streptozotocin-induced diabetic rats. Our data showed that the final fasting serum glucose level was significantly lower in the M2000-treated group compared to the diabetic control group (p < .05). In addition, the final fasting serum insulin level significantly increased in the M2000-treated group compared to the diabetic control group (p < .05). Our finding revealed that the serum level of hs-CRP and IL-6 decreased significantly in the M2000-treated group compared to the diabetic control group (p < .05). This study showed that M2000, as a new NSAID, was able to decrease serum glucose levels and increase serum insulin levels and this drug could significantly decrease the inflammatory markers in the M2000-treated group. Collectively, treatment with M2000 might be recommended reducing the severity of diabetes-induced inflammatory symptoms.

Myricetin ameliorates high glucose-induced endothelial dysfunction in human umbilical vein endothelial cells

Endothelial dysfunction is recognized as the initial detectable stage of cardiovascular disease, a serious complication of diabetes. In this study, we evaluated effects of myricetin on high glucose (HG)-elicited oxidative damage in human umbilical vein endothelial cells (HUVECs). The cells were pre-incubated with myricetin and then treated with HG to induce apoptosis. The effect of myricetin on viability was investigated by MTT assay. The levels of lipid peroxidation (LPO) were determined by thiobarbituric acid (TBA) method. The protein expression of Bax, Bcl-2 and caspase-3 was measured by western blot analysis. Moreover, the effect of myricetin on total antioxidant capacity (TAC) and total thiol molecules was also determined. Our results showed that myricetin was able to markedly restore the viability of endothelial cells under oxidative stress. Myricetin reduced HG-caused increase in LPO levels. Also, TAC and total thiol molecules were notably elevated by myricetin. Incubation with myricetin decreased the protein expression levels of Bax, whereas it increased the expression levels of the Bcl-2, compared with HG treatment alone. Furthermore, myricetin significantly decreased cleaved caspase-3 protein expression. It is concluded that myricetin may protect HUVECs from oxidative stress induced by HG via increasing cell TAC and reducing Bax/Bcl-2 protein ratio, and caspase-3 expression.

A Protective Effect of PPARα in Endothelial Progenitor Cells Through Regulating Metabolism

Deficiency of endothelial progenitor cells, including endothelial colony-forming cells (ECFCs) and circulating angiogenic cells (CACs), plays an important role in retinal vascular degeneration in diabetic retinopathy (DR). Fenofibrate, an agonist of peroxisome proliferator-activated receptor α (PPARα), has shown therapeutic effects on DR in both patients and diabetic animal models. However, the function of PPARα in ECFC/CACs has not been defined. In this study, we determined the regulation of ECFC/CAC by PPARα. As shown by flow cytometry and Seahorse analysis, ECFC/CAC numbers and mitochondrial function were decreased in the bone marrow, circulation, and retina of db/db mice, correlating with PPARα downregulation. Activation of PPARα by fenofibrate normalized ECFC/CAC numbers and mitochondrial function in diabetes. In contrast, PPARα knockout exacerbated ECFC/CAC number decreases and mitochondrial dysfunction in diabetic mice. Primary ECFCs from PPARα -/- mice displayed impaired proliferation, migration, and tube formation. Furthermore, PPARα -/- ECFCs showed reduced mitochondrial oxidation and glycolysis compared with wild type, correlating with decreases of Akt phosphorylation and expression of its downstream genes regulating ECFC fate and metabolism. These findings suggest that PPARα is an endogenous regulator of ECFC/CAC metabolism and cell fate. Diabetes-induced downregulation of PPARα contributes to ECFC/CAC deficiency and retinal vascular degeneration in DR.

Milk in the prevention and management of type 2 diabetes: The potential role of milk proteins

Globally, diabetes mellitus is not only considered a leading cause of mortality and morbidities but has also created a substantial economic burden. There is growing evidence that foods and their components can be implemented in the prevention and management of type 2 diabetes mellitus (T2DM). Increased dairy consumption has been linked to a lower risk of T2DM. The protective role of dairy foods in the development of T2DM is thought to be largely attributable to dairy nutrients, one of them being dairy protein. There is considerable evidence that milk proteins increase the postprandial insulin response and lower the postprandial blood glucose response in both healthy subjects and patients with T2DM. The exact mechanisms by which milk proteins lower postprandial glucose levels are yet to established; however, the amino acids and bioactive peptides derived from milk proteins are thought to modify a physiological milieu, which includes delayed gastric emptying and the enhancement of incretin and insulin responses, consequently leading to lower postprandial glucose levels. The present review will focus on providing a clear presentation of the potential implementation of milk proteins as a dietary supplement in the prevention and management of T2DM by summarizing the relevant supporting evidence for this particular topic.

The effects of chromium and vitamin D3 co-supplementation on insulin resistance and tumor necrosis factor-alpha in type 2 diabetes: a randomized placebo-controlled trial

The current study was conducted to assess the effects of simultaneous usage with vitamin D₃ and chromium picolinate (CrPic) supplementations on homeostasis model assessment of insulin resistance (HOMA-IR), fasting blood glucose (FBS), hemoglobin A1c (HbA1c), tumor necrosis factor-α (TNF-α), and lipid profile in type 2 diabetes mellitus (T2DM). Ninety-two patients with T2DM were randomly allocated to the following 4 groups for 4 months: (I) placebo of vitamin D₃ (n = 23); (II) vitamin D₃ supplement at a dose of 50 000 IU/week (n = 23); (III) CrPic supplement at a dose of 500 μg/day (n = 23); and (IV) both vitamin D₃ at a dose of 50 000 IU/week and CrPic at a dose of 500 μg/day (n = 23). HOMA-IR levels increased significantly in groups I and II after the intervention. However, this increase in group I was significantly higher than that in group II after the treatment. HOMA-IR levels were controlled in groups III and IV during the intervention. TNF-α decreased significantly in groups II, III, and IV after the intervention. FBS, HbA1c, and lipid profile did not change significantly in total groups after the intervention. It seems that chromium and vitamin D₃ co-supplementation are probably effective in controlling HOMA-IR by decreasing TNF-α in T2DM. Novelty Chromium alone and/or in simultaneous pretreatment with vitamin D₃ is more effective than vitamin D₃ in controlling HOMA-IR in T2DM. Chromium and vitamin D₃ alone and/or in simultaneous pretreatment decrease TNF-α in T2DM.

Acute and Direct Effects of Sodium-Glucose Cotransporter 2 Inhibition on Glomerular Filtration Rate in Spontaneously Diabetic Torii Fatty Rats

Recent clinical studies indicate that sodium-glucose cotransporter 2 (SGLT2) inhibitors exhibit a renoprotective effect. While studies at the single nephron level suggest that direct effects of SGLT2 inhibitors on renal hemodynamics may be a possible mechanism underlying their renoprotective effect, few studies have focused on such direct effects at the whole-kidney level. In the present study, we investigated the acute and direct effect of SGLT2 inhibition on creatinine clearance, an index of whole-kidney glomerular filtration rate (GFR), in a rat model of type 2 diabetes. Twelve to fifteen-week-old male Spontaneously Diabetic Torii (SDT) fatty rats and Sprague-Dawley rats were used as diabetic animals and non-diabetic controls, respectively. Under general anesthesia, baseline urine samples were collected from the left and right ureters for 1 h. The selective SGLT2 inhibitor ipragliflozin or vehicle was subsequently administered intravenously and post-drug urine was collected for 1 h. Baseline and post-drug blood samples were collected immediately before baseline urine collection and immediately after post-drug urine collection, respectively. Plasma glucose, urine volume, urinary glucose and albumin excretion were measured, and creatinine clearance was calculated. Blood pressure and heart rate were monitored continuously throughout the experiment. A single intravenous injection of ipragliflozin increased both urine output and glucose excretion, but reduced creatinine clearance without affecting systemic blood pressure. These results suggest that SGLT2 inhibition directly reduced whole-kidney GFR, most likely due to a reduction in intraglomerular pressure, by altering local renal hemodynamics, which may contribute to the renoprotective effects demonstrated in clinical studies.

Diabetic neuropathy in children and adolescents with type 1 diabetes mellitus: Diagnosis, pathogenesis, and associated genetic markers

Diabetic neuropathy (DN) is a common long-term complication of type 1 (T1D) and type 2 (T2D) diabetes mellitus, with significant morbidity and mortality. DN is defined as impaired function of the autonomic and/or peripheral nervous system, often subclinical, particularly in children and adolescents with T1D. Nerve conduction studies (NCS) and skin biopsies are considered gold-standard methods in the assessment of DN. Multiple environmental and genetic factors are involved in the pathogenesis of DN. Specifically, the role of metabolic control and glycemic variability is of paramount importance. A number of recently identified genes, including the AKR1B1, VEGF, MTHFR, APOE, and ACE genes, contribute significantly in the pathogenesis of DN. These genes may serve as biomarkers to predict future DN development or treatment response. In addition, they may serve as the basis for the development of new medications or gene therapy. In this review, the diagnostic evaluation, pathogenesis, and associated genetic markers of DN in children and adolescents with T1D are presented and discussed.

Deregulation of long noncoding RNA SNHG17 and TTC28-AS1 is associated with type 2 diabetes mellitus

Long noncoding RNAs (lncRNAs) have emerged as key players in several biological processes and complex diseases including type 2 diabetes mellitus (T2DM). The purpose of this study was to investigate the expression levels of SNHG17 and TTC28-AS1 in T2DM patients. Quantitative real-time RT-PCR analysis was performed using peripheral blood mononuclear cells (PBMCs) samples from patients diagnosed with T2DM and healthy controls. Binary logistic regression analysis was carried out to determine the odds of development of T2DM based on expression levels of lncRNAs and clinical characteristic of the subjects. Spearman's correlation analysis was used to clarify the correlation between SNHG17 and TTC28-AS1 expressions to metabolic features. We found that SNHG17 and TTC28-AS1were down-regulated in the T2DM group compared to the healthy control group. The logistic regression revealed that body mass index (BMI), systolic blood pressure (SBP), fasting blood glucose (FBG) and TTC28-AS1 expression substantially affect T2DM susceptibility. Furthermore, expression of SNHG17 was negatively correlated with high-density lipoprotein cholesterol (HDL-C) and expression of TTC28-AS1 was positively correlated with low-density lipoprotein cholesterol (LDL-C). Decreased expressions of lncRNAs TTC28-AS1 and SNHG17 in T2DM are possibly associated with the development of T2DM.