Constant and intermittent high glucose enhances endothelial cell apoptosis through mitochondrial superoxide overproduction

Overview of in situ gelling injectable hydrogels for diabetic wounds

Diabetes mellitus (DM) is an endocrine disorder that causes increased blood glucose than usual due to insulin impairment. In DM, several complications arise in which diabetic wound (DW) is the most devastating complication. About 25% of patients with DM expected to develop DWs in their lifetime and undergo limb amputations. Even though several treatments such as surgery, debridement, wound dressings, advanced therapies were available, the overall conclusion has been that with very few exceptions, patients still suffer from limitations like pain, frequent dress changing, high rates of failure, and cost involvement. Further, the treatments involving the delivery of therapeutic agents in treating DWs have limited success due to abnormal levels of proteases in the DW environment. In this backdrop, in situ gelling injectable hydrogels have gained special attention due to their easy encapsulation of therapeutic medications and prolonged release, filling the wound defect areas, ease of handling, and minimally invasive surgical procedures. Though the in situ gelling injectable hydrogels are developed a couple of decades ago, their use for treating DW has not yet been explored thoroughly. Thus, in this review, we have covered the sequential events of DW healing, pathophysiology, current treatments, and its limitations, along with a particular emphasis on the mechanism of action of these in situ gelling injectable hydrogels treating DWs.

Regulation of Dendrobium Polysaccharides on Proliferation and Oxidative Stress of Human Umbilical Vein Endothelial Cells in the High Glucose Environment

BACKGROUNDS

Polysaccharides of Dendrobium candidum (PDC) showed a strong antioxidant effect on islet cells while the effects of PDC on human umbilical vein endothelial cells (HUVECs) under the high glucose condition remain unclear. Material and Method. HUVECs were incubated with high glucose (33.3 mmol/L) for 48 hours to induce injury, and cells were treated with PDC (100, 200, and 400 μg/mL) for 48 hours. The tetrazolium blue colorimetric (MTT) assay was used to detect cell proliferation, superoxide dismutase (SOD), and nitric oxide (NO) content in cell supernatants. Flow cytometry was used to detect reactive oxygen species (ROS) and calcium levels.

RESULTS

(1) Compared with the control group, the proliferation of HUVECs cells in the high glucose (33.3 mmol/L) group decreased (P < 0.05). The intracellular calcium ion concentration and the intracellular ROS level increased (P < 0.01 and P < 0.05). SOD activity and the level of NO in the culture medium were reduced (P <0.05). (2) Compared with the control group, PDC (50, 100, 200, 400, and 800 μg/mL) did not significantly affect the cell proliferation of HUVECs (P > 0.05). (3) Compared with the high glucose group, the HUVEC cell viability of the high glucose + PDC (100, 200, and 400 μg/mL) group increased while the intracellular calcium ion concentration decreased in a concentration-dependent manner (P < 0.05). Intracellular ROS levels were reduced, while SOD activity and the level of NO in culture fluids increased (P < 0.05).

CONCLUSION

PDC can promote the proliferation of HUVECs in the high glucose environment by reducing oxidative stress injury of HUVECs induced by high glucose.

Advances of hydrogel dressings in diabetic wounds

The hydrogel dressings with various functions for diabetic wound treatment.

Microneedle arrays for the treatment of chronic wounds

INTRODUCTION

Chronic wounds are seen frequently in diabetic and bedbound patients. Such skin injuries, which do not heal in a timely fashion, can lead to life-threatening conditions. In an effort to resolve the burdens of chronic wounds, numerous investigations have explored the efficacy of various therapeutics on wound healing. Therapeutics can be topically delivered to cutaneous wounds to reduce the complications associated with systemic drug delivery because the compromised skin barrier is not expected to negatively affect drug distribution. However, researchers have recently demonstrated that the complex environment of chronic wounds could lower the localized availability of the applied therapeutics. Microneedle arrays (MNAs) can be exploited to enhance delivery efficiency and consequently improved healing.

AREAS COVERED

In this review, we briefly describe the pathophysiology of chronic wounds and current treatment strategies. We further introduce methods and materials commonly used for the fabrication of MNAs. Subsequently, the studies demonstrating the benefits of MNAs in wound care are highlighted.

EXPERT OPINION

Microneedles have great potential to treat the complicated pathophysiology of chronic wounds. Challenges that will need to be addressed include development of a robust chronic wound model and MNAs that combine complex functionality with simplicity of use.

Bioinformatic Reconstruction and Analysis of Gene Networks Related to Glucose Variability in Diabetes and Its Complications

Glucose variability (GV) has been recognized recently as a promoter of complications and therapeutic targets in diabetes. The aim of this study was to reconstruct and analyze gene networks related to GV in diabetes and its complications. For network analysis, we used the ANDSystem that provides automatic network reconstruction and analysis based on text mining. The network of GV consisted of 37 genes/proteins associated with both hyperglycemia and hypoglycemia. Cardiovascular system, pancreas, adipose and muscle tissues, gastrointestinal tract, and kidney were recognized as the loci with the highest expression of GV-related genes. According to Gene Ontology enrichment analysis, these genes are associated with insulin secretion, glucose metabolism, glycogen biosynthesis, gluconeogenesis, MAPK and JAK-STAT cascades, protein kinase B signaling, cell proliferation, nitric oxide biosynthesis, etc. GV-related genes were found to occupy central positions in the networks of diabetes complications (cardiovascular disease, diabetic nephropathy, retinopathy, and neuropathy) and were associated with response to hypoxia. Gene prioritization analysis identified new gene candidates (THBS1, FN1, HSP90AA1, EGFR, MAPK1, STAT3, TP53, EGF, GSK3B, and PTEN) potentially involved in GV. The results expand the understanding of the molecular mechanisms of the GV phenomenon in diabetes and provide molecular markers and therapeutic targets for future research.

Visit-to-visit fasting plasma glucose variability is associated with left ventricular adverse remodeling in diabetic patients with STEMI

Background

Patients with type 2 diabetes mellitus (T2DM) are predisposed to poor cardiovascular outcomes after ST-segment elevation myocardial infarction (STEMI). Left ventricular adverse remodeling (LVAR) triggered upon myocardial infarction is recognized as the predominant pathological process in the development of heart failure. In the present study, we sought to investigate whether visit-to-visit fasting plasma glucose (FPG) variability is a potential predictor of LVAR in T2DM patients after STEMI.

Methods

From January 2014 to December 2018 in Ruijin Hospital, T2DM patients with STEMI who underwent primary percutaneous coronary intervention were consecutively enrolled and followed up for ~ 12 months. The changes in left ventricular geometric and functional parameters between baseline and 12-month follow-up were assessed by echocardiography. The incidence of LVAR, defined as 20% increase in indexed left ventricular end-diastolic volume (LVEDV), and its relationship with visit-to-visit FPG variability were analyzed. Multivariate regression models were constructed to test the predictive value of FPG variability for post-infarction LVAR.

Results

A total of 437 patients with type 2 diabetes and STEMI were included in the final analysis. During a mean follow-up of 12.4 ± 1.1 months, the incidence of LVAR was 20.6% and mean enlargement of indexed LVEDV was 3.31 ± 14.4 mL/m², which was significantly increased in patients with higher coefficient variance (CV) of FPG (P = 0.002) irrespective of baseline glycemic levels. In multivariate analysis, FPG variability was independently associated with incidence of post-infarction LVAR after adjustment for traditional risk factors, baseline HbA1c as well as mean FPG during follow-up (OR: 3.021 [95% CI 1.081–8.764] for highest vs. lowest tertile of CV of FPG). Assessing FPG variability by other two measures, including standard deviation (SD) and variability independent of the mean (VIM), yielded similar findings.

Conclusions

This study suggests that visit-to-visit FPG variability is an independent predictor of incidence of LVAR in T2DM patients with STEMI.

Trial registration Trials number, NCT02089360; registered on March 17,2014.

Ultrasound and Near-Infrared Light Dual-Triggered Upconversion Zeolite-Based Nanocomposite for Hyperthermia-Enhanced Multimodal Melanoma Therapy via a Precise Apoptotic Mechanism

High reactive oxygen species (ROS) generation efficiency and induction of targeted cell apoptosis are recognized as key objectives to achieve a highly efficient strategy for cancer therapy with minimum side effects of inflammatory reactions. However, it is still a challenge to realize higher therapeutic efficiency with a cell apoptosis model. Herein, we present strong upconversion luminescent biosafe cores derived from Linde Type A (LTA) zeolites and modification with targeted/therapeutic drugs for multimodal therapy, in which sonodynamic therapy (SDT) combined with photodynamic therapy (PDT) increases therapeutic efficiency especially in deep sites of tumor via producing cytoplasmic ROS and mitochondrial superoxide and photothermal therapy (PTT) enhances PDT effects via higher fluorescence resonance energy transfer (FRET) efficacy attributed to an increased temperature. Furthermore, the transcriptomic analysis reveals that cellular internalization of the nanosystem can lead to tumor ablation via cell apoptosis. We expect that the multimodal therapy based on LTA zeolite drug nanocarriers could be applied in the cancer therapeutics in the near future.

Pre-Procedural Hyperglycemia Increases the Risk of Contrast-Induced Nephropathy in Patients Undergoing Coronary Angiography: A Systematic Review and Meta-Analysis

BACKGROUND

Contrast-induced nephropathy (CIN) frequently occurs following coronary angiography (CAG) and is associated with worse outcomes, including both short and long-term mortality. Previous studies reported an association between procedural hyperglycemia (PH) and CIN, with or without diabetes mellitus (DM). We performed a systematic review and meta-analysis to explore the association of PH and CIN in patients undergoing CAG.

METHODS

We searched the databases of MEDLINE and EMBASE from inception to January 2020. Included studies investigated CIN incidence in patients undergoing CAG. Data from each study were combined using the random-effects model.

RESULTS

A total of eight studies were included in this meta-analysis. We found that PH was associated with an increased risk of CIN following CAG (pooled OR = 1.71, 95%CI:1.35-2.16, where PH was defined as ≥140 mg/dl; and pooled OR = 2.07, 95%CI:1.80-2.37, where PH was defined as ≥200 mg/dl). In subgroup analysis of non-diabetic patients and STEMI patients undergoing primary percutaneous coronary intervention, we found that PH was associated with an increased risk of CIN in both subgroups, where PH was defined as ≥140 mg/dl and ≥200mg/dl (p-value < 0.05).

CONCLUSIONS

Our meta-analysis demonstrated that PH significantly increases the risk of CIN following CAG, in both diabetic and non-diabetic populations. Further studies are needed to evaluate whether strict blood glucose control can reduce the incidence of CIN in this population.

Increased Postoperative Glucose Variability Is Associated With Adverse Outcome Following Two-Stage Exchange Arthroplasty for Periprosthetic Joint Infection

BACKGROUND

Glucose variability in the postoperative period has been associated with increased rates of periprosthetic joint infection (PJI) following primary arthroplasty. It is unknown how postoperative glucose control affects outcome of surgical treatment of PJI patients. We hypothesized that postoperative glucose variability adversely affects the outcome of 2-stage exchange arthroplasty.

METHODS

We retrospectively reviewed records of 665 patients with PJI of the knee and hip who underwent 2-stage exchange arthroplasty from 2000 to 2017. Of them, 341 PJIs with a minimum follow-up of 1 year, and either a minimum of 2 glucose values per day or greater than 3 overall during the reimplantation were included. Glucose variability was assessed by calculating the coefficient of variation. Adverse outcomes included treatment failure according to the Delphi consensuses criteria, reinfection, reoperation, and mortality. A subgroup analysis was performed based on patients with or without diabetes.

RESULTS

Glucose variability following reimplantation was associated with higher treatment failure, reinfection, and reoperation. Adjusted analysis indicated that for every standard deviation (15%) increase in the coefficient of variation, the risks of treatment failure, reinfection, and reoperation increased by 27%, 31%, and 26%. Although stratifying patients with (n = 81) or without diabetes (n = 260), these associations remained robust in nondiabetic patients, but not in diabetic patients.

CONCLUSION

Higher glucose variability is associated with increased risks of treatment failure, reinfection, and reoperation after 2-stage exchange arthroplasty in PJI patients. Compared to diabetic patients, nondiabetic patients have a higher association between glucose variability and poor outcomes. Reducing adverse outcomes may be achieved with close monitoring and strict postoperative glucose control.

Interferon-γ and high glucose-induced opening of Cx43 hemichannels causes endothelial cell dysfunction and damage

Both IFN-γ or high glucose have been linked to systemic inflammatory imbalance with serious repercussions not only for endothelial function but also for the formation of the atherosclerotic plaque. Although the uncontrolled opening of connexin hemichannels underpins the progression of various diseases, whether they are implicated in endothelial cell dysfunction and damage evoked by IFN-γ plus high glucose remains to be fully elucidated. In this study, by using live cell imaging and biochemical approaches, we demonstrate that IFN-γ plus high glucose augment endothelial connexin43 hemichannel activity, resulting in the increase of ATP release, ATP-mediated Ca²⁺ dynamics and production of nitric oxide and superoxide anion, as well as impaired insulin-mediated uptake and intercellular diffusion of glucose and cell survival. Based on our results, we propose that connexin 43 hemichannel inhibition could serve as a new approach for tackling the activation of detrimental signaling resulting in endothelial cell dysfunction and death caused by inflammatory mediators during atherosclerosis secondary to diabetes mellitus.

How tightly controlled do fluctuations in blood glucose levels need to be to reduce the risk of developing complications in people with Type 1 diabetes?

In 2011, the James Lind Alliance published a 'top 10' list of priorities for Type 1 diabetes research based on a structured consultation process. Whether reducing fluctuations in blood glucose can prevent long-term microvascular and macrovascular complications was one of these. In this narrative review, 8 years on, we have assessed the updated evidence for the assertion that increased glucose variability plays an independent and clinically important role in the complications of Type 1 diabetes, over and above mean blood glucose and the effects of hypoglycaemia: the 'glucose variability hypothesis'. Although studies in cultured cells and ex vivo vessels have been suggestive, most studies in Type 1 diabetes have been small and/or cross-sectional, and based on 'finger-prick' glucose measurements that capture glucose variability only in waking hours and are affected by missing data. A recent analysis of the Diabetes Control and Complications Trial that formally imputed missing data found no independent effect of short-term glucose variability on long-term complications. Few other high-quality longitudinal studies have directly addressed the glucose variability hypothesis in Type 1 diabetes. We conclude that there is little substantial evidence to date to support this hypothesis in Type 1 diabetes, although increasing use of continuous glucose monitoring provides an opportunity to test it more definitively. In the meantime, we recommend that control of glycaemia in Type 1 diabetes should continue to focus on the sustained achievement of target HbA_1c and avoidance of hypoglycaemia.

Efficacy of Vildagliptin Added to Continuous Subcutaneous Insulin Infusion (CSII) in Hospitalized Patients with Type 2 Diabetes

INTRODUCTION

The aim of this study was to compare the efficacy of vildagliptin as add-on therapy to short-term continuous subcutaneous insulin infusion (CSII) with CSII monotherapy in hospitalized patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 200 hospitalized patients with inadequately controlled T2DM were randomized into groups, with one group receiving CSII monotherapy (CSII group, n =100) and the other group receiving CSII plus vildagliptin as add-on (CSII + Vig group, n = 100). Of these, 191 completed the 7-day trial (CSII group, n = 99; CSII + Vig group, n = 92) and included in the analysis. The glycemic control and variability of the patients were measured using all-day capillary blood glucose (BG) monitoring. Weight and fasting C-peptide levels were evaluated before and after the interventions.

RESULTS

Mean BG concentrations during the whole treatment period were lower and the time to reach target BG was reduced in the CSII + Vig group compared with the CSII group (9.89 ± 3.37 vs. 9.46 ± 3.23 mmol/L, P < 0.01; 129 ± 4 vs. 94 ± 5 h, P < 0.01, respectively). Similarly, the indicators of glycemic variability, namely the standard deviation of BG and the largest amplitude of glycemic excursion, were significantly decreased in the CSII + Vig group compared with the CSII group (2.68 ± 1.05 vs. 2.39 ± 1.00 mmol/L, P < 0.01; 7.19 ± 2.86 vs. 6.23 ± 2.73 mmol/L, P < 0.01, respectively).

CONCLUSIONS

Short-term CSII with vildagliptin as add-on therapy may be an optimized treatment for hospitalized patients with T2DM compared with short-term CSII monotherapy.

Acute hyperglycemia and contrast-induced nephropathy in patients with non-ST elevation myocardial infarction

Acute hyperglycemia and contrast-induced nephropathy (CIN) are frequently observed in non-ST elevation myocardial infarction (NSTEMI) patients undergoing percutaneous coronary intervention (PCI), and both are associated with an increased mortality rate. We investigated the possible association between acute hyperglycemia and CIN in patients with NSTEMI undergoing PCI.

Materials and methods

We retrospectively enrolled 281(149, 53% men) NSTEMI patients undergoing PCI. For each patient, plasma glucose levels were secreened at hospital admission. Acute hyperglycemia was defined as glucose levels > 198 mg/dl. CIN was defined as an increase in serum creatinine 25% or 0.5 mg/dl from baseline in the first 48-72 hours.

Results

Overall, 44 (15.7%) patients had acute hyperglycemia. Patients with acute hyperglycemia had higher incidence of CIN than those without acute hyperglycemia (29.5 vs 5.1%, P < 0.001). Also, in-hospital mortality, length of hospital stay, major bleeding, requirement of mechanical ventilation and dialysis were observed significantly higher in patients with hyperglycemia. Patients were then reallocated to two groups according to the presence or absence of CIN. Overall, 25 cases (8.9%) of CIN were diagnosed. Diabetes mellitus, weight, age, glucose level and estimated glomerular filtration rate (eGFR) were detected as independent risk factors of CIN. Additionally, admission glucose levels were significantly correlated with creatinine levels after PCI, eGFR and contrast volume/eGFR ratio.

Conclusion

In NSTEMI patients undergoing primary PCI, acute hyperglycemia may be associated with an increased risk for CIN and in-hospital mortality and morbidity.

Elevated 1-h post-load plasma glucose levels in normal glucose tolerance children with obesity is associated with early carotid atherosclerosis

CONTEXT

Evidence suggests that the 1-h post-load plasma glucose (1-h PG) ≥155mg/dL during an oral glucose tolerance test (OGTT) predicts development of type 2 diabetes (T2DM) and associated complications, among adults with normal glucose tolerance (NGT), but relevant data on children is scarce.

OBJECTIVES

To investigate whether NGT children with obesity whose 1-h PG is ≥155mg/dL have an increased carotid intima-media thickness (IMT) and exhibit non-alcoholic fatty liver disease (NAFLD) diagnosed by ultrasonography, as compared with NGT subjects with 1-h PG <155mg/dL and impaired glucose tolerance (IGT).

METHODS

Cardio-metabolic profile, OGTT, measurements of carotid IMT and liver ultrasonography were analyzed in 171 non-diabetic children with obesity. Subjects were divided into 3 groups: NGT subjects with a 1-h PG <155mg/dL, NGT subjects with a 1-h PG ≥155mg/dL, and IGT subjects.

RESULTS

As compared with NGT individuals with a 1-h PG <155mg/dL, NGT individuals with a 1-h PG ≥155mg/dL exhibited higher carotid IMT (0.75±0.15mm vs. 0.68±0.15mm; p<0.05). No significant differences were observed in carotid IMT between IGT and NGT subjects with a 1-h PG ≥155mg/dL (0.75±0.18mm vs 0.75±0.15mm; p>0.05). Of the three glycemic parameters, 1-h and 2-h PG, but not fasting glucose, were significantly correlated with carotid IMT. There were no significant differences for increased risk of having NAFLD between the three groups.

CONCLUSIONS

These data suggest that a value of 1-h PG ≥155mg/dL in children and adolescents with obesity is as important as IGT with respect to cardiovascular risks.

Fasting plasma glucose variability and HbA1c are associated with peripheral artery disease risk in type 2 diabetes

BACKGROUND

This study investigated whether visit-to-visit fasting plasma glucose (FPG) variability, as measured by the coefficient of variation (CV), increased peripheral artery disease (PAD) risk.

METHODS

Individuals with type 2 diabetes from the National Diabetes Care Management Program during the period 2002-2004, ≥ 30 years of age, and free of PAD (n = 30,932) were included and monitored until 2011. Cox proportional hazards regression models were implemented to analyze related determinants of PAD.

RESULTS

A total of 894 incident cases of PAD were identified during an average 8.2 years of follow-up, resulting in a crude incidence rate of 3.53 per 1000 person-years. Both FPG-CV and HbA1c were significantly associated with PAD after multivariate adjustment, with corresponding hazard ratios of 1.24 [95% confidence interval (CI) 1.04-1.47] for FPG-CV in the third tertile and 1.50 (95% CI 1.10-2.04) for HbA1c ≥ 10%. The findings of the sensitivity analysis remained consistent after excluding potential confounders, demonstrating the consistency of the results.

CONCLUSIONS

The associations between HbA1c, variability in FPG-CV, and PAD suggest a linked pathophysiological mechanism, suggesting the crucial role of glycemic variability in clinical management and therapeutic goals in preventing PAD in type 2 diabetes.

Association of Glycemic Indices (Hyperglycemia, Glucose Variability, and Hypoglycemia) with Oxidative Stress and Diabetic Complications

Oxidative stress (OS) is defined as a disturbance in the prooxidant-antioxidant balance of the cell, in favor of the former, which results in the antioxidant capacity of the cell to be overpowered. Excess reactive oxygen species (ROS) production is very harmful to cell constituents, especially proteins, lipids, and DNA, thus causing damage to the cell. Oxidative stress has been associated with a variety of pathologic conditions, including diabetes mellitus (DM), cancer, atherosclerosis, neurodegenerative diseases, rheumatoid arthritis, ischemia/reperfusion injury, obstructive sleep apnea, and accelerated aging. Regarding DM specifically, previous experimental and clinical studies have pointed to the fact that oxidative stress probably plays a major role in the pathogenesis and development of diabetic complications. It is postulated that hyperglycemia induces free radicals and impairs endogenous antioxidant defense systems through several different mechanisms. In particular, hyperglycemia promotes the creation of advanced glycation end-products (AGEs), the activation of protein kinase C (PKC), and the hyperactivity of hexosamine and sorbitol pathways, leading to the development of insulin resistance, impaired insulin secretion, and endothelial dysfunction, by inducing excessive ROS production and OS. Furthermore, glucose variability has been associated with OS as well, and recent evidence suggests that also hypoglycemia may be playing an important role in favoring diabetic vascular complications through OS, inflammation, prothrombotic events, and endothelial dysfunction. The association of these diabetic parameters (i.e., hyperglycemia, glucose variability, and hypoglycemia) with oxidative stress will be reviewed here.

Effect of Prestroke Glycemic Variability Estimated Glycated Albumin on Stroke Severity and Infarct Volume in Diabetic Patients Presenting With Acute Ischemic Stroke

Background: We investigated whether prestroke glycemic variability, represented by glycated albumin (GA), affects the initial stroke severity and infarct volume in diabetic patients presenting with acute ischemic stroke. Methods: We evaluated a total of 296 acute ischemic stroke patients with diabetes mellitus who were hospitalized within 48 h of stroke onset. GA was measured in all acute ischemic stroke patients consecutively during the study period. The primary outcome was the initial National Institute Health Stroke Scale (NIHSS) score. The secondary outcome was infarct volume on diffusion-weighted imaging, which was performed within 24 h of stroke onset. Higher GA (≥16.0%) was determined to reflect glycemic fluctuation prior to ischemic stroke. Results: The number of patients with higher GA was 217 (73.3%). The prevalence of a severe initial NIHSS score (>14) was higher in patients with higher GA than in those with lower GA (3.8% vs. 15.7%, p = 0.01). The proportion of participants in the highest quartile of infarct volume was higher in the higher GA group (11.4% vs. 36.4%, p < 0.001). A multivariable analysis showed that higher GA was significantly associated with a severe NIHSS score (odds ratio, [95% confidence interval], 7.99 [1.75-36.45]) and large infarct volume (3.76 [1.05-13.45]). Conclusions: Prestroke glucose variability estimated by GA was associated with an increased risk of severe initial stroke severity and large infarct volume in acute ischemic stroke patients with diabetes mellitus.

HbA1c variability in adults with type 1 diabetes on continuous subcutaneous insulin infusion (CSII) therapy compared to multiple daily injection (MDI) treatment

OBJECTIVE

To determine if continuous subcutaneous insulin infusion (CSII) therapy is associated with lower glycated haemoglobin (HbA1c) variability (long-term glycaemic variability; GV) relative to multiple daily injection (MDI) treatment in adults with type 1 diabetes mellitus (T1DM).

DESIGN

Retrospective audit.

SETTING AND PARTICIPANTS

Clinic records from 506 adults with T1DM from two tertiary Australian hospitals.

OUTCOME MEASURES

Long-term GV was assessed by HbA1c SD and coefficient of variation (CV) in adults on established MDI or CSII therapy, and in a subset changing from MDI to CSII.

RESULTS

Adults (n=506, (164 CSII), 50% women, mean±SD age 38.0±15.3 years, 17.0±13.7 years diabetes, mean HbA1c 7.8%±1.2% (62±13 mmol/mol) on CSII, 8.0%±1.5% (64±16 mmol/mol) on MDI) were followed for 4.1±3.6 years. CSII use was associated with lower GV (HbA1c SD: CSII vs MDI 0.5%±0.41% (6±6 mmol/mol) vs 0.7%±0.7% (9±8 mmol/mol)) and CV: CSII vs MDI 6.7%±4.6% (10±10 mmol/mol) vs 9.3%±7.3% (14±13 mmol/mol), both p<0.001. Fifty-six adults (73% female, age 36±13 years, 16±13 years diabetes, HbA1c 7.8%±0.8% (62±9 mmol/mol)) transitioned from MDI to CSII. Mean HbA1c fell by 0.4%. GV from 1 year post-CSII commencement decreased significantly, HbA1c SD pre-CSII versus post-CSII 0.7%±0.5% (8±5 mmol/mol) vs 0.4%±0.4% (5±4 mmol/mol); p<0.001, and HbA1c CV 9.2%±5.5% (13±8 mmol/mol) vs 6.1%±3.9% (9±5 mmol/mol); p<0.001.

CONCLUSIONS

In clinical practice with T1DM adults relative to MDI, CSII therapy is associated with lower HbA1c GV.

Diabetes, dysglycemia, and vascular surgery

BACKGROUND

Abnormalities in glucose metabolism are common in patients with arterial disease. Chronic hyperglycemia and insulin resistance contribute to the complexity of vascular disorders. They also overlap with the effects of perioperative hyperglycemia on adverse perioperative outcomes. We provide an overview of the pathophysiologic consequences of dysglycemia and the evidence behind glycemic control in patients undergoing vascular surgery.

METHODS

We searched the literature for major studies evaluating the pathophysiology of hyperglycemia in microvascular and macrovascular beds, randomized trials in perioperative populations, and meta-analyses. The literature was summarized to guide therapy in the population of vascular patients and for the perioperative period.

RESULTS

National standards for glycemic control after vascular interventions were not identified. Mounting evidence exists for the long-term consequences of poor glycemic control on the progression of vascular disease. Similarly, there is a large body of evidence supporting tight control of hyperglycemia after general and cardiac surgery during the critical perioperative period. The absolute glucose target remains controversial. Randomized controlled studies are lacking in vascular surgery patients, but the current evidence can be extrapolated to guide management after vascular interventions. Glycated hemoglobin is a biomarker for increased mortality and vascular morbidity after vascular surgery.

CONCLUSIONS

Hyperglycemia contributes to poor outcome in the vascular patient. Further vascular focused studies are required to determine the proper perioperative serum glucose target and the long-term glycated hemoglobin range.

The Effects of Folic Acid Administration on Cardiac Oxidative Stress and Cardiovascular Biomarkers in Diabetic Rats

The aim of this study was to examine the effects of folic acid administration on the antioxidant enzyme (superoxide dismutase (SOD) and catalase (CAT)) activities, lactate and malate dehydrogenase (LDH and MDH) activities, and certain LDH and MDH isoform distribution in the cardiac tissue of diabetic Wistar male rats. Diabetes mellitus (DM) was induced by streptozotocin (STZ). There were five groups: C1-control (physiological saline 1 ml/kg, i.p. one day), C2-control with daily physiological saline treatment (1 ml/kg, i.p. 28 days), DM-diabetes mellitus (STZ 100 mg/kg in physiological saline, i.p. one day), FA-folic acid (5 mg/kg in physiological saline, i.p. 28 days), and DM+FA-diabetes mellitus and folic acid group (STZ 100 mg/kg in physiological saline, i.p. one day, and folic acid 5 mg/kg in physiological saline, i.p. 28 days). After four weeks, animal hearts were isolated for measurement of enzyme activities, as well as for histomorphometry analyses. An elevated glucose level and a decreased insulin level were obtained in the DM group. SOD, CAT, and MDH activities were elevated in the DM group, while there was no difference in LDH activity among the groups. In all tested groups, four LDH and three MDH isoforms were detected in the heart tissue, but with differences in their relative activities among the groups. Left ventricular cardiomyocyte transversal diameters were significantly smaller in both diabetic groups. Folic acid treatment of diabetic rats induced a reduced glucose level and reduced CAT, SOD, and MDH activities and alleviated the decrease in cardiomyocyte diameters. In conclusion, increased activities of antioxidant enzymes and MDH may be the consequence of oxidative stress caused by DM. Administration of the folic acid has a protective effect since it leads to reduction in glycemia and activities of the certain examined enzymes in the rats with experimentally induced DM.

A Protective Role of Paeoniflorin in Fluctuant Hyperglycemia-Induced Vascular Endothelial Injuries through Antioxidative and Anti-Inflammatory Effects and Reduction of PKCβ1

Hyperglycemia fluctuation is associated with diabetes mellitus (DM) complications when compared to persistent hyperglycemia. Previous studies have shown that paeoniflorin (PF), through its antiapoptosis, anti-inflammation, and antithrombotic properties, effectively protects against cardiovascular and cerebrovascular disease. However, the mechanism underlying the protection from PF against vascular injuries induced by hyperglycemia fluctuations remains poorly understood. Herein, we investigated the potential protective role of PF on human umbilical vein endothelial cells (HUVECs) subjected to intermittent glucose levels in vitro and in DM rats with fluctuating hyperglycemia in vivo. A remarkable increased apoptosis associated with elevated inflammation, increased oxidative stress, and high protein level of PKCβ1 was induced in HUVECs by intermittently changing glucose for 8 days, and PF recovered those detrimental changes. LY333531, a potent PKCβ1 inhibitor, and metformin manifested similar effects. Additionally, in DM rats with fluctuating hyperglycemia, PF protected against vascular damage as what has been observed in vitro. Taken together, PF attenuates the vascular injury induced by fluctuant hyperglycemia through oxidative stress inhibition, inflammatory reaction reduction, and PKCβ1 protein level repression, suggesting its perspective clinical usage.

Icariin Attenuates High Glucose-Induced Apoptosis, Oxidative Stress, and Inflammation in Human Umbilical Venous Endothelial Cells

Endothelial dysfunction is closely associated with diabetic complications. Icariin, a flavonoid glycoside isolated from the Epimedium plant species, exhibits antidiabetic properties. However, its impact on endothelial function remains poorly understood, particularly under hyperglycemia. In this study, we investigated the potential protective effect of icariin on high glucose-induced detrimental effects on vascular endothelial cells. Human umbilical venous endothelial cells were incubated in media containing 5.5 mM glucose (normal glucose) or 25 mM glucose (high glucose) in the presence or absence of 50 µM icariin for 72 h. We found that high glucose markedly induced cell apoptosis, enhanced reactive oxygen species generation, and elevated expression levels of inflammatory factors and cell adhesion molecules, which were greatly subdued by icariin supplementation. In conclusion, icariin exerted a beneficial effect on high glucose-induced endothelial dysfunction. This new finding provides a promising strategy for future treatment of diabetic vascular complications.

The early detection of atherosclerosis in type 1 diabetes: why, how and what to do about it

The major cause of morbidity and often premature mortality in people with type I diabetes (T1D) is cardiovascular disease owing to accelerated atherosclerosis. We review publications relating to the rationale behind, and clinical tests for, detecting and treating early atherosclerosis in people with T1D. Currently available tools for atherosclerosis assessment include risk equations using vascular risk factors, arterial intima-media thickness, the ankle-brachial index, coronary artery calcification and angiography, and for more advanced lesions, intravascular ultrasound and optical coherence tomography. Evolving research tools include risk equations incorporating novel clinical, biochemical and molecular tests; vascular MRI and molecular imaging. As yet there is little information available to quantify early atherosclerosis. With better means to control the vascular risk factors, such as hypertension, dyslipidaemia and glycaemic control, and emerging therapies to control novel risk factors, further epidemiologic and clinical trials are merited to facilitate the translation into clinical practice of robust means to detect, monitor and treat early atherosclerosis in those with T1D.

High blood glucose variability is associated with bacteremia and mortality in patients hospitalized with acute infection

BACKGROUND

Limited data are available regarding the association between glucose levels variability (GV) and outcomes of patients hospitalized with acute infectious diseases.

AIM

To determine the association between GV and bacteremia, length of stay (LOS) and mortality.

METHODS

A retrospective study of patients hospitalized in departments of medicine with respiratory tract, urinary tract and skin and soft tissue infections during 2011-17. GV was assessed by the coefficient of variation (CV) of glucose levels during hospitalization and was divided into tertiles (CV ≤ 16%, 17-29%, >29%). LOS, bacteremia rates and all-cause mortality (30 days, 90 days and after 5 years) were evaluated for the patients with and without DM according the three GV categories.

RESULTS

The study consisted of 1485 patients, 838 (56%) were diabetic. There was no significant association between GV and LOS. Bacteremia rates were higher in the upper GV tertile compared with the lower one (6% vs. 2%, P = 0.007). Mid and upper tertiles compared with the lower one were significantly associated with increased 30-day mortality (13% vs. 5%, P = 0.005; and 40% vs. 5%, P = 0.002, respectively). A decreased 5 years survival was observed for both diabetic and non-diabetic patients in the mid and upper GV tertiles [adjusted HRs 0.8 (95% CI, 0.6-1.04) and 0.6 (95% CI, 0.5-0.9) in diabetic patients and 0.7 (95% CI, 0.5-0.9) and 0.5 (95% CI, 0.3-0.7) in the non-diabetic ones].

CONCLUSION

In diabetic and non-diabetic patients, hospitalized in non-ICU setting with acute infectious diseases, increased GV is associated with increased risk of bacteremia, short and long-term mortality.

Prolonged Hyperglycemia and Renal Failure after Primary Percutaneous Coronary Intervention

BACKGROUND

There are limited data regarding the effect of long-standing hyperglycemia on the occurrence of acute kidney injury (AKI) in ST segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI).

METHODS

We retrospectively studied 723 STEMI patients undergoing primary PCI. Patients were stratified into two groups according to glycated hemoglobin (HbA1c) levels as a marker of prolonged hyperglycemia: those with HbA1c < 7% and those with HbA1c ≥7%. Medical records were reviewed for the occurrence of AKI.

RESULTS

HbA1c levels ≥7% were found in 225/723 (31%) of patients. The occurrence of AKI was significantly higher among patients with HbA1c levels ≥7% (32/225, 14%) compared to patients with HbA1c levels < 7% (32/498, 6%; p = 0.001). Patients with chronic kidney disease (CKD) and HbA1c ≥7% had an eight-fold increase in the incidence of AKI compared to patients with HbA1c < 7% and no CKD (32 vs. 4%). In a multivariable regression model, HbA1c ≥7% was independently associated with AKI (OR 1.92, 95% CI 1.09-3.36, p = 0.02).

CONCLUSION

HbA1c ≥7% was associated with a higher likelihood of AKI in STEMI patients treated with primary PCI.

Molecular Mechanisms of Glucose Fluctuations on Diabetic Complications

Accumulating evidence indicates the occurrence and development of diabetic complications relates to not only constant high plasma glucose, but also glucose fluctuations which affect various kinds of molecular mechanisms in various target cells and tissues. In this review, we detail reactive oxygen species and their potentially damaging effects upon glucose fluctuations and resultant downstream regulation of protein signaling pathways, including protein kinase C, protein kinase B, nuclear factor-κB, and the mitogen-activated protein kinase signaling pathway. A deeper understanding of glucose-fluctuation-related molecular mechanisms in the development of diabetic complications may enable more potential target therapies in future.

Klotho protein inhibits H2O2-induced oxidative injury in endothelial cells via regulation of PI3K/AKT/Nrf2/HO-1 pathways

Klotho protein secreted in the blood could act as a hormone to regulate various target organs and have a protective effect on the cardiovascular system. Numerous studies had shown that Klotho protein had antioxidative stress, anti-inflammatory, and antiapoptotic effects on vascular endothelial cells. The purpose of this study was to investigate the protective mechanism of Klotho protein on oxidative damage of vascular endothelial cells induced by H₂O₂. Klotho protein significantly enhanced human umbilical vein endothelial cells viability and increased the activities of antioxidant enzymes (superoxide dismutase, catalase, and heme oxygenase-1 (HO-1)), scavenged reactive oxygen species, and inhibited tumor necrosis factor alpha and interleukin 6 secretion. Klotho protein also reduced the rate of apoptosis of cells and improved the function of vascular endothelial cells (increased nitric oxide secretion). Klotho protein activated nuclear translocation of Nrf2 and increased HO-1 expression. Klotho protein also activated phosphorylation of protein kinase B (AKT), whereas the addition of LY294002, a pharmacological inhibitor of phosphatidylinositol 3-kinase (PI3K), blocked Klotho-protein-induced Nrf2/HO-1 activation and cytoprotection. Klotho protein enhanced the antioxidant defense ability of the cells by activating the PI3K/AKT pathway, which upregulated the expression of Nrf2/HO-1, thereby inhibiting H₂O₂-induced oxidative damage.

Association between glycemic control, age, and outcomes among intensively treated patients with acute myeloid leukemia

PURPOSE

To investigate the impact of hyperglycemia and glycemic variability during intensive acute myeloid leukemia therapy (AML) on outcomes by age.

METHODS

Retrospective study of 262 consecutive patients with newly diagnosed AML hospitalized for intensive induction. Hyperglycemia was assessed by mean blood glucose (BG) (mg/dL) during hospitalization and glycemic variability was determined by the standard deviation (SD) of mean BG. Outcomes were complete remission ± incomplete count recovery (CR + CRi), and overall survival (OS). We used logistic regression to evaluate CR + CRi, and Cox proportional hazard models for OS, stratified by age (< 60 vs ≥ 60 years).

RESULTS

Older patients (N = 138, median age 70) had higher baseline comorbidity (CCI > 1 60.1% vs 25.8%) and prevalence of diabetes (20.3% vs 7.3%) compared to younger (N = 124, median age 47). The mean ± SD number of BG values obtained per patient during hospitalization was 61 ± 71. The mean (± SD) glucose (mg/dL) during hospitalization was 121.7 (25.9) in older patients (≥ 60 years) versus 111.6 (16.4) in younger. In older patients, higher mean glucose and greater glycemic variability were associated with lower odds of remission (OR 0.80, 95% CI 0.69-0.93 and OR 0.73, 95% CI 0.61-0.88 respectively, per 10-unit increase) and higher mortality rates (HR 1.13, 95% CI 1.05-1.21 and HR 1.17, 95% CI 1.09-1.26, respectively, per 10-unit increase) in multivariate analyses.

CONCLUSIONS

Our observations that hyperglycemia and increased glycemic variability were associated with lower remission rates and increased mortality in older patients suggest glycemic control may be a potentially modifiable factor to improve AML outcomes.

Suppression of Apoptosis in Human Umbilical Vein Endothelial Cells (HUVECs) by Klotho Protein is Associated with Reduced Endoplasmic Reticulum Oxidative Stress and Activation of the PI3K/AKT Pathway

BACKGROUND Klotho protein has been shown to act as a hormone on the cardiovascular system, and to have specific protective effects on vascular endothelial cells. The aim of this study was to investigate the mechanisms of the anti-oxidative and anti-apoptotic effects of klotho protein on hydrogen peroxide (H₂O₂)-induced apoptosis and endoplasmic reticulum oxidative stress in human umbilical vein endothelial cells (HUVECs). MATERIAL AND METHODS HUVECs were cultured in vitro and treated with H₂O₂. The MTT assay evaluated cell viability of H₂O₂-treated HUVECs, and flow cytometry measured cell apoptosis. An enzyme-linked immunosorbent assay (ELISA) measured the levels of nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), and interleukin (IL)-6. Western blot was used to detect the expression of the proteins, 78 kD glucose-regulated protein (GRP78), CCAAT-enhancer-binding protein homologous protein (CHOP), caspase-3, caspase-9, caspase-12, and AKT. The effects of LY294002, a pharmacological inhibitor of PI3K, were evaluated. RESULTS Klotho protein increased the viability of H2O2-treated HUVECs and reduced the expression of NO, TNF-α, and IL-6. Klotho protein reduced the rate of apoptosis of H₂O₂-treated HUVECs and downregulated the expression of proteins associated with endoplasmic reticulum oxidative stress, GRP78 and CHOP, and the expression of the apoptotic proteins, caspase-3, caspase-9, and caspase-12, and activated the phosphorylation of AKT. The addition of LY294002 inhibited klotho protein downregulation of GRP78, CHOP, caspase-3, caspase-9, and caspase-12 expression. CONCLUSIONS In HUVECs, klotho protein suppressed apoptosis mediated by endoplasmic reticulum oxidative stress by activation of the PI3K/AKT pathway.

Recurrent short-term hypoglycemia and hyperglycemia induce apoptosis and oxidative stress via the ER stress response in immortalized adult mouse Schwann (IMS32) cells

Hypoglycemia and fluctuating high or low glucose conditions are under-appreciated sources of oxidative stress contributing to diabetic neuropathy. We investigated the effects of recurrent short-term hypoglycemia and hyperglycemia, on apoptosis and oxidative stress in Schwann cells. Immortalized adult mouse Schwann (IMS32) cells were exposed to five different glucose treatments over 3 days: 1) normal glucose (NG), 2) constant low glucose (LG), 3) constant high glucose (HG), 4) intermittent low glucose (ILG; 1 h three times per day), 5) intermittent high glucose (IHG; 1 h three times per day). Cell viability was decreased by all treatment variants, in comparison to NG. Thiobarbituric acid reactive substance (TBARS) levels were increased by HG, LG, IHG, and ILG. High glucose (HG and IHG) and low glucose (LG and ILG) increased the expression of cleaved caspase-3 and reduced that of Bcl-2. In addition, endoplasmic reticulum (ER) stress-responsive transcription factor C/EBP homologous protein (CHOP) expression was increased under low and high glucose conditions. Cell death and oxidative stress induced by HG, LG, IHG, and ILG were significantly reduced by 4-phenyl butyric acid (4-PBA), an ER stress inhibitor. These findings indicate that recurrent short-term hypoglycemia and hyperglycemia induce apoptosis and oxidative stress via the ER stress response in Schwann cells.

Simvastatin attenuates the aberrant expression of angiogenic factors induced by glucose variability

AIM

Over the last few years, studies have indicated that fluctuant hyperglycemia is very likely to increase the risk of cardiovascular complications of diabetes. Statins are widely used in diabetes for the prevention of cardiovascular complications, but it is still not clear whether simvastatin could also prevent glycaemic variability - induced aberrant angiogenesis which plays a significant role in the development of atherosclerosis.

METHODS

Wistar rats were divided into four groups: (1) simvastatin-treated (20 mg/kg for 8 consecutive weeks) type 2 diabetes rat model with daily glucose excursions, (2) placebo-treated type 2 diabetes rat model with daily glucose excursions, (3) placebo-treated stable well-controlled type 2 diabetes rat model and (4) placebo-treated non-diabetic rats. Daily glucose fluctuations and several angiogenic factors: cVEGF, mRNA VEGF, VEGF-R1, VEGF-R2, TGF-beta expression, circulating endothelial and progenitor endothelial cells were measured in all groups.

RESULTS

Simvastatin decreased several factors enhanced by glucose excursions: circulating VEGF, mRNA TGF-beta expression in the myocardium and mRNA VEGFR-2 expression in the aorta. Simvastatin increased some factors attenuated by glucose fluctuations: mRNA VEGF expression and mRNA VEGFR-1 expression in the myocardium and in the aorta. In the simvastatin-treated group with glycaemic variability, the percentage of circulating endothelial cells was lower and the percentage of progenitor endothelial cells in peripheral blood was higher than in the placebo-treated rats with glucose-fluctuations.

CONCLUSIONS

Simvastatin used in the rat model of type 2 diabetes with glucose variability reduces glucose variability and limits glucose fluctuations-induced changes in the expression of angiogenic factors in the cardiovascular system.

Wider perioperative glycemic fluctuations increase risk of postoperative atrial fibrillation and ICU length of stay

INTRODUCTION

Postoperative atrial fibrillation (POAF) is a common complication following cardiac surgery associated with increased morbidity and mortality. Although sustained hyperglycemia is a known risk factor of AF and poor ICU outcomes, emerging in-vitro studies reveal acute glycemic fluctuations to be an additional independent predictor of AF. The effect of acute glycemic fluctuations on the incidence of POAF in the clinical setting remains unclear. We aim to investigate the effect of the magnitude of acute perioperative glycemic fluctuations on the incidence of POAF in a multi-ethnic Southeast-Asian population.

METHODS

We obtained data from1743 patients who underwent elective CABG in a tertiary heart centre from 2009-2011. Patients were kept to a tight baseline glycemic control in accordance with hospital protocol. The magnitude of the difference between the highest and lowest perioperative glucose levels up till the first 48 postoperative hours was employed as a measure of glycemic fluctuation. Patients were divided into 4 groups for analysis based on the magnitude of glycemic fluctuation:A)0-2mmol/L(N = 147); B)>2-4mmol/L(N = 426); C)>4-6mmol/L(N = 513); D)>6mmol/L(N = 657).Our primary outcome was the incidence of POAF. Secondary outcomes included ICU and 30-day mortality and length of stay.

RESULTS

The overall incidence of POAF was 14.7%. This increased as the magnitude of glycemic fluctuation increased, and was statistically highest in Group D(16.4%) as compared with the other 3 sub-groups. Multivariate logistic regression revealed the magnitude of perioperative glycemic fluctuation to be an independent risk factor of POAF(O.R.1.06, 95% C.I.1.01-1.11, p = 0.014).ICU length of stay was statistically highest in Group D(63.1 hours, p = < .001). However, ICU and 30 day mortality rates were similar among the 4 groups.

CONCLUSION

Increased magnitudes of acute perioperative glycemic fluctuations are associated with a significantly increased risk of POAF and length of ICU stay; and should therefore be minimised but balanced against the risks of hypoglycemia so as to avoid POAF and optimise patient outcomes.

Heat shock protein 70 modulates neural progenitor cells dynamics in human neuroblastoma SH-SY5Y cells exposed to high glucose content

In the current experiment, detrimental effects of high glucose condition were investigated on human neuroblastoma cells. Human neuroblastoma cell line SH-SY5Y were exposed to 5, 40, and 70 mM glucose over a period of 72 h. Survival rate and the proliferation of cells were analyzed by MTT and BrdU incorporation assays. Apoptosis was studied by the assays of flow cytometry and PCR array. In order to investigate the trans-differentiation capacity of the cell into mature neurons, we used immunofluorescence imaging to follow NeuN protein level. The transcription level of HSP70 was shown by real-time PCR analysis. MMP-2 and -9 activities were shown by gelatin Zymography. According to data from MTT and BrdU incorporation assay, 70 mM glucose reduced cell viability and proliferation rate as compared to control (5 mM glucose) and cells treated with 40 mM glucose (P < 0.05). Cell exposure to 70 mM glucose had potential to induced apoptosis after 72 h (P < 0.05). Our results also demonstrated the sensitivity of SH-SY5Y cells to detrimental effects of high glucose condition during trans-differentiation into mature neuron-like cells. Real-time PCR analysis confirmed the expression of HSP70 in cells under high content glucose levels, demonstrating the possible cell compensatory response to an insulting condition (p_{control vs 70 mM group} <0.05). Both MMP-2 and -9 activities were reduced in cells being exposed to 70 mM glucose. High glucose condition could abrogate the dynamics of neural progenitor cells. The intracellular level of HSP70 was proportional to cell damage in high glucose condition.

Glycemic extremes are related to cognitive dysfunction in children with type 1 diabetes: A meta-analysis

Aims/Introduction

To examine the magnitude and pattern of cognitive dysfunction in children with type 1 diabetes, and the possible effects associated with other disease variables, such as early onset diabetes, severe hypoglycemia and hyperglycemia.

Materials and Methods

We carried out a meta‐analysis using the Preferred Reporting Items for Systematic Reviews and Meta‐Analysis guidelines. We searched MedLine, Embase and PsycINFO to identify studies on cognitive function in children with type 1 diabetes that were published up until 30 September 2016. Effect sizes understood as the standardized mean differences between groups with diabetes and control groups (i.e., Hedges’ g) were calculated to quantify the extent of cognitive dysfunction in those groups consisting of children with diabetes.

Results

A total of 19 studies met our inclusion criteria, comprising 1,355 participants with type 1 diabetes and 696 controls. Compared with non‐diabetic controls, children with type 1 diabetes showed a significantly poorer cognitive performance overall (g = −0.46), as well as specific deficits in full‐scale intelligence (g = −1.06), attention (g = −0.60) and psychomotor speed (g = −0.46). Glycemic extremes were associated with poorer overall cognition (g = −0.18), as well as slightly lower performance in memory (g = −0.27).

Conclusions

We found that type 1 diabetes was associated with cognitive dysfunction characterized by a lowered intelligence, diminished attention and a slowing of psychomotor speed. Glycemic extremes, which are described as a period of high glucose levels and severe hypoglycemia, were related to cognitive dysfunction in children with type 1 diabetes.

Population-based cohort study suggesting a significantly increased risk of developing chronic obstructive pulmonary disease in people with type 2 diabetes mellitus

AIMS

To investigate whether type 2 diabetes mellitus (T2DM) increases the risk of developing chronic obstructive pulmonary disease (COPD).

METHODS

This population-based cohort study used Taiwan's National Health insurance claim data to investigate the association of T2DM with the risk of COPD. A total of 716,623 pairs of people (patients with T2DM and their age-, sex-, and calendar year-matched controls) were identified in 2002-2003 and were followed until the occurrence of newly-diagnosed COPD or the end of 2011. Cox proportional hazard models were used to relate COPD incidence to T2DM.

RESULTS

People with T2DM experienced a higher incidence rate of COPD than controls (159.6 vs 122.7 per 10⁴ person-years). After controlling for confounders, T2DM significantly increased the hazard of COPD (hazard ratio [HR] = 1.15, 95% confidence interval = 1.14-1.16). Stratified analysis indicated that the association between T2DM and COPD was slightly greater in women than in men (HR, 1.15 vs. 1.11) and in people aged <65 years than in people aged ≥65 years (HR, 1.17 vs. 1.05 in men; 1.16 vs. 1.13 in women).

CONCLUSIONS

Our findings demonstrated a modest association of T2DM with the risk of developing COPD, possibly shedding light into the adverse effects of hyperglycemia on pulmonary function.

Teneligliptin enhances the beneficial effects of GLP-1 in endothelial cells exposed to hyperglycemic conditions

High-glucose-induced oxidative stress contributes to cardiovascular endothelial damage in diabetes. Glucagon-like peptide 1 (GLP-1) is beneficial to endothelial cells, but its effects are diminished when cells are continuously exposed to high glucose. Teneligliptin is a dipeptidyl peptidase-4 (DPP-4) inhibitor that prevents oxidative stress, apoptosis and the metabolic memory effect. We explored the potential additive effects of Teneligliptin and GLP-1 in hyperglycemia-damaged endothelial cells. Human umbilical vein endothelial cells (HUVECs) were exposed to normal-glucose (5 mmol/L) or high-glucose (HG, 25 mmol/L) for 21 days, or to HG for 14 days followed by normal-glucose for 7 days (HM). These cells were continually treated with Teneligliptin 3.0 μmol/L, alone or in combination with an acute dose of GLP-1 50 nmol/L. DPP-4 was upregulated under hyperglycemic conditions, but Teneligliptin reduced DPP-4 expression and activity. Simultaneous Teneligliptin and GLP-1 synergistically increased the antioxidant response and reduced ROS levels in HG- and HM-exposed HUVECs. Concurrent treatment also enhanced cell proliferation, reduced apoptotic gene expression and ameliorated endoplasmic reticulum stress in HG- and HM-exposed HUVECs. Thus, long-term Teneligliptin treatment reduced DPP-4 levels and activity in HUVECs exposed to chronic hyperglycemia. Moreover, Teneligliptin enhanced the beneficial effects of GLP-1 on oxidative stress, proliferation, apoptosis and endoplasmic reticulum homeostasis.

Uncoupling Protein 2 Inhibition Exacerbates Glucose Fluctuation-Mediated Neuronal Effects

Though glucose fluctuations have been considered as an adverse factor for the development of several diabetes-related complications, their impact in the central nervous system is still not fully elucidated. This study was conducted to evaluate the responses of neuronal cells to different glycemic exposures alongside to elucidate the role of uncoupling protein 2 (UCP2) in regulating such responses. To achieve our goals, primary cortical neurons were submitted to constant high (HG)/low (LG) or glucose level variations (GVs), and the pharmacological inhibition of UCP2 activity was performed using genipin. Results obtained show that GV decreased neuronal cells' viability, mitochondrial membrane potential, and manganese superoxide dismutase activity and increased reactive oxygen species (ROS) production. GV also caused an increase in the glutathione/glutathione disulfide ratio and in the protein expression levels of nuclear factor E2-related factor 2 (NRF2), UCP2, NADH-ubiquinone oxidoreductase chain 1 (ND1), and mitochondrially encoded cytochrome c oxidase I (MTCO1), both mitochondrial DNA encoded subunits of the electron transport chain. Contrariwise, genipin abrogated all those compensations and increased the levels of caspase 3-like activity, potentiated mitochondrial ROS levels, and the loss of neuronal synaptic integrity, decreased the protein expression levels of NRF1, and increased the protein expression levels of UCP5. Further, in the control and LG conditions, genipin increased mitochondrial ROS and the protein expression levels of UCP4, postsynaptic density protein 95 (PSD95), ND1, and MTCO1. Overall, these observations suggest that UCP2 is in the core of neuronal cell protection and/or adaptation against GV-mediated effects and that other isoforms of neuronal UCPs can be upregulated to compensate the inhibition of UCP2 activity.

Upregulation of miR-195 accelerates oxidative stress-induced retinal endothelial cell injury by targeting mitofusin 2 in diabetic rats

This study was performed to investigate the oxidative stress-induced miRNA changes in relation to pathogenesis of diabetic retinopathy (DR) and to establish a functional link between miRNAs and oxidative stress-induced retinal endothelial cell injury. Our results demonstrated that oxidative stress could induce alterations of miRNA expression profile, including up-regulation of miR-195 in the diabetic retina or cultured HMRECs after exposed to H₂O₂ or HG (P < 0.05). Oxidative stress also resulted in a significant reduction of MFN2 expression in diabetic retina or HMRECs (P < 0.05). Overexpression of miR-195 reduced MFN2 protein levels, and induced tube formation and increased permeability of diabetic retinal vasculature. The luciferase reporter assay confirmed that miR-195 binds to the 3' -untranslated region (3'-UTR) of MFN2 mRNA. This study suggested that miR-195 played a critical role in oxidative stress-induced retinal endothelial cell injury by targeting MFN2 in diabetic rats.

Galangin, a natural flavonoid reduces mitochondrial oxidative damage in streptozotocin-induced diabetic rats

Objective: We designed this study to observe the effect of galangin on damaged mitochondria in the liver of diabetic rats.

Methods: Male albino Wistar rats were made diabetic by injecting streptozotocin (STZ) intraperitoneally (40 mg kg⁻¹ body weight (BW)). Galangin (8 mg kg⁻¹ BW) or glibenclamide (600 µg kg⁻¹ BW) was given orally daily once for 45 days to both healthy and diabetic rats.

Results: Diabetic rats showed significant (P < 0.05) increase in liver mitochondrial oxidant [Thiobarbituric acid reactive substance (TBARS)] level and a significant decrease in enzymatic [superoxide dismutase (SOD), glutathione peroxidase (GPx)] and non-enzymatic (reduced glutathione (GSH)) antioxidant levels when compared with healthy rats. The mitochondrial enzymes isocitrate dehydrogenase (ICDH), alpha-ketoglutarate dehydrogenase (α-KGDH), succinate dehydrogenase (SDH) and malate dehydrogenase (MDH) and mitochondrial respiratory chain enzymes NADH-dehydrogenase and Cytochrome c-oxidase were decreased significantly (P < 0.05) in diabetic rats when compared with healthy rats. A natural flavonoid galangin administered to hyperglycemia-induced rats resulted in the following findings as compared to hyperglycemia-induced control rats: the oxidant levels decreased significantly (P < 0.05); the enzymatic and non-enzymatic antioxidant levels increased significantly (P < 0.05) and the function of mitochondrial enzymes and the mitochondrial respiratory chain enzymes increased significantly (P < 0.05).

Conclusion: From the results, we conclude that galangin could maintain liver mitochondrial function in diabetic rats.

Effects of Co-Culture Media on Hepatic Differentiation of hiPSC with or without HUVEC Co-Culture

The derivation of hepatocytes from human induced pluripotent stem cells (hiPSC) is of great interest for applications in pharmacological research. However, full maturation of hiPSC-derived hepatocytes has not yet been achieved in vitro. To improve hepatic differentiation, co-cultivation of hiPSC with human umbilical vein endothelial cells (HUVEC) during hepatic differentiation was investigated in this study. In the first step, different culture media variations based on hepatocyte culture medium (HCM) were tested in HUVEC mono-cultures to establish a suitable culture medium for co-culture experiments. Based on the results, two media variants were selected to differentiate hiPSC-derived definitive endodermal (DE) cells into mature hepatocytes with or without HUVEC addition. DE cells differentiated in mono-cultures in the presence of those media variants showed a significant increase (p < 0.05) in secretion of α-fetoprotein and in activities of cytochrome P450 (CYP) isoenzymes CYP2B6 and CYP3A4 as compared with cells differentiated in unmodified HCM used as control. Co-cultivation with HUVEC did not further improve the differentiation outcome. Thus, it can be concluded that the effect of the used medium outweighed the effect of HUVEC co-culture, emphasizing the importance of the culture medium composition for hiPSC differentiation.