Evidence that hyperglycemia after recovery from hypoglycemia worsens endothelial function and increases oxidative stress and inflammation in healthy control subjects and subjects with type 1 diabetes

Phosphatidylserine on microparticles and associated cells contributes to the hypercoagulable state in diabetic kidney disease

Background

Relatively little is known about the role of phosphatidylserine (PS) in procoagulant activity (PCA) in patients with diabetic kidney disease (DKD). This study was designed to evaluate whether exposed PS on microparticles (MPs) and MP-origin cells were involved in the hypercoagulability in DKD patients.

Methods

DKD patients (n = 90) were divided into three groups based on urinary albumin excretion rate, defined as normoalbuminuria (No-A) (<30 mg/24 h), microalbuminuria (Mi-A) (30-299 mg/24 h) or macroalbuminuria (Ma-A) (>300 mg/24 h), and compared with healthy controls (n = 30). Lactadherin was used to quantify PS exposure on MPs and their original cells. Healthy blood cells (BCs) and human umbilical vein endothelial cells (HUVECs) were treated with 25, 5 or 2.5 mmol/L glucose as well as 3-12 mg/dL uric acid and cells were evaluated by clotting time and purified coagulation complex assays. Fibrin production was determined by turbidity. PS exposure and fibrin strands were observed using confocal microscopy.

Results

Using flow cytometry, we found that PS+ MPs (derived from platelets, erythrocytes, HUVECs, neutrophils, monocytes and lymphocytes) and BCs were significantly higher in patients than in controls. Furthermore, the number of PS+ MPs and BCs in patients with Ma-A was significantly higher than in patients with No-A. Similarly, we observed markedly elevated PS exposure on HUVECs cultured with serum from patients with Ma-A versus serum from patients with Mi-A or normoalbuminuria. In addition, circulating PS+ MPs cooperated with PS+ cells, contributing to markedly shortened coagulation time and dramatically increased FXa/thrombin generation and fibrin formation in each DKD group. Confocal microscopy images demonstrated colocalization of fibrin with PS on HUVECs. Moreover, blockade of exposed PS on MPs and cells with lactadherin inhibited PCA by ∼80%. In vitro, BCs and endothelial cells exposed more PS in hypoglycemia or hyperglycemia. Interestingly, reconstitution experiments showed that hypoglycemia-treated cells could be further activated or injured when recovery is obtained reaching hyperglycemia. Moreover, uric acid induced PS exposure on cells (excluding platelets) at concentrations >6 mg/dL. Linear regression analysis showed that levels of PS+ BCs and microparticles were positively correlated with uric acid and proteinuria, but negatively correlated with glomerular filtration rate.

Conclusions

Our results suggest that PS+ MPs and MP-origin cells play procoagulant roles in patients with DKD. Blockade of PS could become a novel therapeutic modality for the prevention of thrombosis in these patients.

Glucagon-like peptide-1 receptor agonists and cardiovascular protection in type 2 diabetes: a pathophysiology-based review of clinical implications

PURPOSE OF REVIEW

Cardiovascular outcome trials (CVOT) with glucagon-like peptide-1 receptor agonists (GLP-1 RA) have had variable results to date: with two CVOTs being positive and two concluding neutrality/safety results for primary cardiovascular outcome. Mechanistic insights delving into the pathophysiologic mechanisms that may link certain GLP-1 RA to cardioprotection may help define the application of this medication class in clinical practice based on the evidence of the CVOT data. We discuss the various mechanisms that have been postulated from animal and preclinical human studies to help explain the benefits observed in CVOTs with GLP-1 RA.

RECENT FINDINGS

Cardiovascular benefits of GLP-1 may be dependent on the complex interactions of this incretin hormone with the atherosclerotic pathways, either through its direct actions on the cardiovascular system or indirectly through intermediary actions on metabolism, energy transfer, inflammation or thrombosis. An indirect metabolic action of GLP-1 RA, via an initial step of achieving glucose homeostasis or balancing inter-organ energy metabolism, leading to favorable downstream effects on the inflammation-thrombosis pathways, finally impacting atherosclerosis, appears compelling.

SUMMARY

In addition to their metabolic benefits, specific GLP-1 RA medications offer cardiovascular protection in high-risk type 2 diabetes. Further mechanistic studies and clinical trials in lower cardiovascular risk populations may help cement the place of this class of medications across the spectrum of type 2 diabetes.

Impaired awareness of hypoglycaemia: A new risk factor for adverse pregnancy outcomes in type 1 diabetes

AIM

The aim of this study is to evaluate the impact of impaired awareness of hypoglycaemia (IAH) on metabolic control and pregnancy outcomes in women with type 1 diabetes.

MATERIAL AND METHODS

This was a single-centre prospective cohort study of singleton pregnant women with type 1 diabetes. IAH was assessed at the first antenatal visit using Clarke's test (score ≥ 3). Data on metabolic control, hypoglycaemic events, and the lipid profile were collected from prior to pregnancy and in each trimester of gestation. Pregnancy outcomes were also recorded.

RESULTS

A total of 77 patients with type 1 diabetes were included; 24 (31.2%) were classified as having IAH. Compared with the normal awareness of hypoglycaemia (NAH) group, the IAH group did not show differences in HbA_1c , weight gain, insulin doses, or severe and nonsevere hypoglycaemia events throughout pregnancy. IAH was associated with higher triglyceride concentrations in the second trimester (IAH: 154.8 ± 61.1 mg/dL, NAH: 128.6 ± 31.2 mg/dL, P = .034) and an increased risk of neonatal respiratory distress (odds ratio [OR] 11.24; 95% CI, 1.01-124.9, P = .041) in adjusted models. Increased risk of pre-eclampsia was related to higher second trimester triglyceride concentrations (OR 1.028; 95% CI, 1.004-1.053, P = .023) adjusted for confounders.

CONCLUSIONS

The IAH was associated with increased risk of neonatal respiratory distress and pre-eclampsia, despite showing no differences in metabolic control. Hypoglycaemia awareness in the first antenatal visit should be assessed to identify the subgroup of pregnant women with increased risk of complications.

Nanofibrous vildagliptin-eluting stents enhance re-endothelialization and reduce neointimal formation in diabetes: in vitro and in vivo

BACKGROUND

The high lifetime risk of vascular disease is one of the important issues that plague patients with diabetes mellitus. Systemic oral vildagliptin administration favors endothelial recovery and inhibits smooth muscle cell (SMC) proliferation. However, the localized release of vildagliptin in the diabetic vessel damage has seldom been investigated.

RESEARCH DESIGN AND METHODS

In this work, nanofiber-eluting stents that loaded with vildagliptin, a dipeptidyl peptidase-4 enzyme (DPP-4) inhibitor, was fabricated to treat diabetic vascular disease. To prepare nanofibers, the poly (D,L)-lactide-co-glycolide (PLGA) and vildagliptin were mixed using hexafluoroisopropanol and electrospinning process. In vitro and in vivo release rates of the vildagliptin were characterized using high-performance liquid chromatography.

RESULTS

Effective vildagliptin concentrations were delivered for more than 28 days from the nanofibrous membranes coating on the surface of the stents in vitro and in vivo. The vildagliptin-eluting PLGA membranes greatly accelerated the recovery of diabetic endothelia and reduced SMC hyperplasia. The type I collagen content of the diabetic vascular intimal area that was treated by vildagliptin-eluting stents was lower than that of the non-vildagliptin-eluting group.

CONCLUSION

The experimental results revealed that stenting with vildagliptin-eluting PLGA membranes could potentially promote healing for diabetic arterial diseases.

Hypoglycemia in diabetes: The dark side of diabetes treatment. A patient-centered review

Hypoglycemia is a frequent occurrence in patients with diabetes who are treated with insulin and insulin secretagogues. Hypoglycemia is the limiting factor that prevents patients from achieving the glycemic control known to reduce the microvascular complications of diabetes. Recurrent episodes of hypoglycemia can lead to impaired awareness of hypoglycemia where the first symptom of a low blood sugar is unconsciousness. The fear of hypoglycemia has a significant effect on the quality of life of patients and their families. In the acute setting, hypoglycemia can kill, and clinical trials have demonstrated that a single episode of severe hypoglycemia increases the risk of subsequent mortality and cardiovascular events. Clinicians must make efforts to recognize and prevent hypoglycemia in order to prevent the adverse events associated with this event. Patient education is central to these efforts. Recent developments in glucose monitoring and drug development have provided more approaches that can be used to reduce the risk of hypoglycemia in patients with diabetes.

Hypoglycaemic treatment adherence and the association with psychological, self-management and glycaemic characteristics in adults with type 1 diabetes

AIM

The purpose of this study was to examine adherence to hypoglycaemia treatment guidelines in adults with type 1 diabetes (T1DM). The American Diabetes Association recommends consumption of 15-20 g of glucose to treat hypoglycaemia. Overtreatment may result in poor glycaemic control and greater glycaemic variability. It is not fully understood how well T1DM adults comply with hypoglycaemia treatment recommendations.

DESIGN

A secondary analysis using a descriptive comparative design.

METHODS

Using real-time measures over six consecutive days, we examined (a) adherence to hypoglycaemia treatment guidelines and (b) comparisons of demographic self-management behaviour, psychological characteristics and glycaemia between adherent and non-adherent groups.

RESULTS

Findings revealed those who overtreated consumed more daily grain servings and reported higher stress and depressed mood compared with those who followed treatment recommendations. Findings suggest that hypoglycaemia treatment practices and psychological factors influencing self-management should be assessed.

Methylglyoxal triggers human aortic endothelial cell dysfunction via modulation of the KATP/MAPK pathway

Endothelial dysfunction is a key risk factor in diabetes-related multiorgan damage. Methylglyoxal (MGO), a highly reactive dicarbonyl generated primarily as a by-product of glycolysis, is increased in both type 1 and type 2 diabetic patients. MGO can rapidly bind with proteins, nucleic acids, and lipids, resulting in structural and functional changes. MGO can also form advanced glycation end products (AGEs). How MGO causes endothelial cell dysfunction, however, is not clear. Human aortic endothelial cells (HAECs) from healthy (H-HAECs) and type 2 diabetic (D-HAECs) donors were cultured in endothelial growth medium (EGM-2). D-HAECs demonstrated impaired network formation (on Matrigel) and proliferation (MTT assay), as well as increased apoptosis (caspase-3/7 activity and TUNEL staining), compared with H-HAECs. High glucose (25 mM) or AGEs (200 ng/ml) did not induce such immediate, detrimental effects as MGO (10 µM). H-HAECs were treated with MGO (10 µM) for 24 h with or without the ATP-sensitive potassium (K_ATP) channel antagonist glibenclamide (1 µM). MGO significantly impaired H-HAEC network formation and proliferation and induced cell apoptosis, which was reversed by glibenclamide. Furthermore, siRNA against the K_ATP channel protein Kir6.1 significantly inhibited endothelial cell function at basal status but rescued impaired endothelial cell function upon MGO exposure. Meanwhile, activation of MAPK pathways p38 kinase, c-Jun NH²-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) (determined by Western blot analyses of their phosphorylated forms, p-JNK, p-p38, and p-ERK) in D-HAECs were significantly enhanced compared with those in H-HAECs. MGO exposure enhanced the activation of all three MAPK pathways in H-HAECs, whereas glibenclamide reversed the activation of p-stress-activated protein kinase/JNK induced by MGO. Glyoxalase-1 (GLO1) is the endogenous MGO-detoxifying enzyme. In healthy mice that received an inhibitor of GLO1, MGO deposition in aortic wall was enhanced and endothelial cell sprouting from isolated aortic segment was significantly inhibited. Our data suggest that MGO triggers endothelial cell dysfunction by activating the JNK/p38 MAPK pathway. This effect arises partly through activation of K_ATP channels. By understanding how MGO induces endothelial dysfunction, our study may provide useful information for developing MGO-targeted interventions to treat vascular disorders in diabetes.

Immune aging in diabetes and its implications in wound healing

Immune systems have evolved to recognize and eliminate pathogens and damaged cells. In humans, it is estimated to recognize 109 epitopes and natural selection ensures that clonally expanded cells replace unstimulated cells and overall immune cell numbers remain stationary. But, with age, it faces continuous repertoire restriction and concomitant accumulation of primed cells. Changes shaping the aging immune system have bitter consequences because, as inflammatory responses gain intensity and duration, tissue-damaging immunity and inflammatory disease arise. During inflammation, the glycolytic flux cannot cope with increasing ATP demands, limiting the immune response's extent. In diabetes, higher glucose availability stretches the glycolytic limit, dysregulating proteostasis and increasing T-cell expansion. Long-term hyperglycemia exerts an accumulating effect, leading to higher inflammatory cytokine levels and increased cytotoxic mediator secretion upon infection, a phenomenon known as diabetic chronic inflammation. Here we review the etiology of diabetic chronic inflammation and its consequences on wound healing.

Glycaemic variability in diabetes: clinical and therapeutic implications

Glycaemic variability is an integral component of glucose homoeostasis. Although it has not yet been definitively confirmed as an independent risk factor for diabetes complications, glycaemic variability can represent the presence of excess glycaemic excursions and, consequently, the risk of hyperglycaemia or hypoglycaemia. Glycaemic variability is currently defined by a large and increasing number of metrics, representing either short-term (within-day and between-day variability) or long-term glycaemic variability, which is usually based on serial measurements of HbA_1c or other measures of glycaemia over a longer period of time. In this Review, we discuss recent evidence examining the association between glycaemic variability and diabetes-related complications, as well as non-pharmacological and pharmacological strategies currently available to address this challenging aspect of diabetes management.

Erythropoietin Pretreatment Effect on Blood Glucose and Its Relationship With Inflammatory Factors After Brain Ischemic-Reperfusion Injury in Rats

Introduction:

Brain Ichemic-Reperfusion Injury (IRI) activates different pathophysiological processes. It also changes physiological parameters such as Blood Glucose (BG) level. An increase in BG after stroke is associated with poor clinical outcomes. Erythropoietin has been shown to be effective on both reducing inflammation and BG level. Therefore, in this study the erythropoietin pretreatment effect on BG and its relationship with inflammatory markers after brain IRI was investigated.

Methods:

Thirty adult male Wistar rats were randomly divided into 5 groups: sham, control and 3 pretreatment groups: single dose, double dose, and triple dose that received 1000 U/kg of erythropoietin before stroke induction in different times intraperitoneally. A rat model of IRI was established by Middle Cerebral Artery Occlusion (MCAO) for 60 minutes. Infarct volume, neurological defects, Interleukin-1α (IL-1α) and IL-6 serum levels were evaluated 24 hours after reperfusion. Also BG was measured after 1, 6, and 24 hours.

Results:

Single dose of erythropoietin significantly decreased infarct volume and improved neurological defects which was associated with decreased serum level of IL-1α and IL-6 but higher doses of erythropoietin administration had adverse effects on histological, neurological, and inflammatory results. In addition, erythropoietin significantly increased BG in a dose-dependent manner.

Conclusion:

Erythropoietin could reduce brain IRI by reducing inflammation and BG stabilization. The results of the present study demonstrated a relationship between inflammatory factors and hyperglycemia after IRI and suggested that erythropoietin may be useful for preventing brain IRI, but its higher doses should be used with caution due to possible side effects.

L-selectin expression is regulated by CXCL8-induced reactive oxygen species produced during human neutrophil rolling

Neutrophils destroy invading microorganisms by phagocytosis by bringing them into contact with bactericidal substances, among which ROS are the most important. However, ROS also function as important physiological regulators of cellular signaling pathways. Here, we addressed the involvement of oxygen derivatives in the regulation of human neutrophil rolling, an essential component of the inflammatory response. Flow experiments using dihydroethidium-preloaded human neutrophils showed that these cells initiate an early production of intracellular ROS during the rolling phase of the adhesion cascade, a phenomenon that required cell rolling, and the interaction of the chemokine receptor CXCR2 with their ligand CXCL8. Flow cytometry experiments demonstrated that L-selectin shedding in neutrophils is triggered by ROS through an autocrine-paracrine mechanism. Preincubation of neutrophils with the NADPH oxidase complex inhibitor diphenyleniodonium chloride significantly increased the number of rolling neutrophils on endothelial cells. Interestingly, the same effect was observed when CXCL8 signaling was interfered using either a blocking monoclonal antibody or an inhibitor of its receptor. These findings indicate that, in response to CXCL8, neutrophils initiate ROS production during the rolling phase of the inflammatory response. This very early ROS production might participate in the modulation of the inflammatory response by inducing L-selectin shedding in neutrophils.

Mitochondrial regulation of diabetic vascular disease: an emerging opportunity

Diabetes-related vascular complication rates remain unacceptably high despite guideline-based medical therapies that are significantly more effective in individuals without diabetes. This critical gap represents an opportunity for researchers and clinicians to collaborate on targeting mechanisms and pathways that specifically contribute to vascular pathology in patients with diabetes mellitus. Dysfunctional mitochondria producing excessive mitochondrial reactive oxygen species (mtROS) play a proximal cell-signaling role in the development of vascular endothelial dysfunction in the setting of diabetes. Targeting the mechanisms of production of mtROS or mtROS themselves represents an attractive method to reduce the prevalence and severity of diabetic vascular disease. This review focuses on the role of mitochondria in the development of diabetic vascular disease and current developments in methods to improve mitochondrial health to improve vascular outcomes in patients with DM.

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.

Poor sleep quality is associated with nocturnal glycaemic variability and fear of hypoglycaemia in adults with type 1 diabetes

AIMS

To examine sleep quality and its associations with glycaemic control, glycaemic variability (GV), and fear of hypoglycaemia (FOH) in adults with type 1 diabetes.

BACKGROUND

Poor sleep quality has negative health consequences and is a frequent complaint among adults with type 1 diabetes. Sleep quality in adults with type 1 diabetes is likely affected by glucose levels as well as stressors associated with managing a chronic condition.

DESIGN

A retrospective secondary analysis of pooled data from two previous cross-sectional studies was conducted.

METHODS

We examined subjective sleep quality, FOH; objective measures of glycaemic control (HbA1c); and GV (3-day continuous glucose monitoring) in 48 men and women aged 18-45 years with type 1 diabetes. The data were collected over 3 years in 2013-2016.

RESULTS/FINDINGS

Poor sleep quality was reported by 46% of patients. Those with poor sleep quality had significantly greater nocturnal GV and FOH. Nocturnal GV and FOH were significantly associated with poor sleep quality. The interaction effect of GV and FOH was significant.

CONCLUSION

These findings suggest that glycaemic control and FOH are targets for intervention to improve sleep quality in those with type 1 diabetes.

Improvements of ambient hyperglycemia and glycemic variability are associated with reduction in oxidative stress for patients with type 2 diabetes

AIMS

We aimed to evaluate which parameters of improvement in glucose metabolism reduce oxidative stress for patients with Type 2 diabetes mellitus (T2DM).

METHODS

Sixty-seven outpatients with T2DM underwent 72 h of continuous glucose monitoring (CGM) and were measured for oxidative stress before and after a 24-week intervention with the following targets: fasting plasma glucose (FPG), <130 mg/dl; postprandial plasma glucose (PPG), <180 mg/dl; and glycated hemoglobin (HbA1c), <7% (53 mmol/mol). The mean glucose level (MGL), mean amplitude of glycemic excursions (MAGE), mean of daily differences (MODD), percentage coefficient of variation for glucose (%CV) and area under the postprandial plasma glucose curve (AUC_PP) were calculated from the CGM data. Oxidative stress was estimated using the diacron-reactive oxygen metabolites (d-ROMs) test. Finally, the association between the improvements in glucose metabolism and oxidative stress was evaluated.

RESULTS

FPG, MGL, HbA1c, MAGE, MODD, %CV, AUC_PP, and d-ROMs significantly improved after 24 weeks of intervention. The change in d-ROMs was significantly correlated with that in FPG (r = 0.414), MGL (r = 0.402), HbA1c (r = 0.271), MAGE (r = 0.457), MODD (r = 0.371), and AUC_PP (r = 0.352). The correlation of the change in d-ROMs with that in FPG, MAGE, and MODD and the use of glucose-like peptide 1 receptor agonists and statins remained significant after adjustment for other markers of diabetes control (multiple R² = 0.406).

CONCLUSIONS

Improvements in glucose metabolism, including FPG and daily and day-to-day glucose variability, were all correlated with reduced oxidative stress for patients with T2DM.

Clinical features and therapeutic perspectives on hypertension in diabetics

Over 50% of patients with diabetes mellitus, either type 1 or 2, ultimately develop hypertension as a complication. In diabetics, this further increases the incidence of cardiovascular disease (CVD) by 2- to 3-fold and accelerates the progression of diabetic nephropathy. Arteriosclerosis, a clinical feature of hypertension in diabetics, develops and advances from a young age. Therefore, in providing treatment, it is necessary to evaluate the degree of arteriosclerosis. Diabetic patients are encouraged to strictly control their blood glucose levels. Recently developed drugs, such as GLP-1 receptor agonists, DPP-4 inhibitors and SGLT2 inhibitors, also have hypotensive actions, making them ideal for use in diabetics with hypertension. SGLT2 inhibitors and GLP-1 receptor agonists reportedly suppress the onset and progression of CVD, as well as diabetic nephropathy. The possibility of hypoglycemia triggering blood pressure elevation and arrhythmia has been noted, so a key point here is not to cause hypoglycemia. In selecting hypotensive agents, we must choose types that do not aggravate insulin resistance and engage in hypotensive treatment that also considers both nocturnal and morning hypertension. In addition, facing the onset of an aging society, there is a growing need for treatments that do not cause excessive blood pressure reduction or hypoglycemia. Favorable lifelong blood pressure and glucose control are increasingly important for the treatment of diabetes accompanied by hypertension.

Diabetic Kidney Disease: Is There a Role for Glycemic Variability?

PURPOSE OF REVIEW

Diabetes is the leading cause of kidney disease globally. Diabetic kidney disease (DKD) is a heterogeneous disorder manifested as albuminuria and/or decreasing GFR. Hyperglycemic burden is the major contributor to the development of DKD. In this article, we review the evidence for the contribution of glycemic variability and the pitfalls associated with use of hemoglobin A1c (A1C), the gold standard for assessment of glucose control, in the setting of DKD.

RECENT FINDINGS

Glycemic variability, characterized by swings in blood glucose levels, can result in generation of mitochondrial reactive oxygen species, a putative inciting factor for hyperglycemia-induced alterations in intracellular metabolic pathways. While there is indirect evidence supporting the role of glycemic variability in the pathogenesis of DKD, definitive data are lacking. A1C has many limitations and is a particularly suboptimal measure in patients with kidney disease, because its accuracy is compromised by variables affecting RBC survival and other factors. Continuous glucose monitoring (CGM) technology has the potential to enable us to use glucose as a more important clinical tool, for a more definitive understanding of glucose variability and its role in DKD. Glycemic variability may be a factor in the development of DKD, but definitive evidence is lacking. Currently, all available glycemic biomarkers, including A1C, have limitations and in the setting of DKD and should be used cautiously. Emerging data suggest that personal and professional CGM will play an important role in managing diabetes in patients with DKD, where risk of hypoglycemia is high.

Influence of blood glucose level on the prognosis of patients with diabetes mellitus complicated with ischemic stroke

We carried out this meta-analysis for the aim of exploring the influence of diabetes mellitus (DM) on the prognosis of patients with ischemic stroke. Relevant studies were identified using computerized databases supplemented with manual search strategies. The included studies were strictly followed the inclusion and exclusion criteria. Case-control studies which related to the influence of DM on the prognosis of patients with ischemic stroke were selected. Statistical analyses were implemented with the STATA version 12.0 statistical software. Our current meta-analysis initially retrieved 253 studies (227 in Chinese and 26 in English), 13 studies (6 in English and 7 in Chinese) were eventually incorporated in this meta-analysis. These 13 case-control studies included 8463 patients altogether (3249 patients with DM complicated with ischemic stroke and 5214 patients with ischemic stroke). The results of this meta-analysis manifested that there was a significant difference of the blood glucose level at 48 h after stroke between patients with DM complicated with ischemic stroke and patients with ischemic stroke (standard mean difference [SMD] =1.27, 95% confidence interval [CI] =0.02–2.51, P = 0.047); however, the effectiveness, fatality, and the National Institutes of Health Stroke Scale (NIHSS) score in patients with DM complicated with ischemic stroke, and patients with ischemic stroke had no significant difference (effectiveness: risk ratio [RR] = 0.88, 95% CI = 0.75–1.03, P = 0.121; fatality: RR = 1.29, 95% CI = 0.97–1.71, P = 0.081; NIHSS score: SMD = −0.14, 95% CI = −1.56-1.28, P = 0.849). The current evidence suggests that there is statistical difference of the blood glucose level at 48 h after stroke between patients with DM complicated with ischemic stroke and patients with ischemic stroke, but there is no statistical difference of prognostic indicators between patients in two groups. Thus, our study provides certain clinical value.

Prospective Study of Fasting Blood Glucose and Intracerebral Hemorrhagic Risk

BACKGROUND AND PURPOSE

Although diabetes mellitus is an established independent risk factor for ischemic stroke, the association between fasting blood glucose and intracerebral hemorrhage (ICH) is limited and inconsistent. The objective of the current study was to examine the potential impact of long-term fasting blood glucose concentration on subsequent risk of ICH.

METHODS

This prospective study included 96 110 participants of the Kailuan study, living in Kailuan community, Tangshan city, China, who were free of cardiovascular diseases and cancer at baseline (2006). Fasting blood glucose concentration was measured in 2006, 2008, 2010, and 2012. Updated cumulative average fasting blood glucose concentration was used as primary exposure of the current study. Incident ICH from 2006 to 2015 was confirmed by review of medical records.

RESULTS

During 817 531 person-years of follow-up, we identified 755 incident ICH cases. The nadir risk of ICH was observed at fasting blood glucose concentration of 5.3 mmol/L. The adjusted hazard ratios and their 95% confidence intervals (CIs) of ICH were 1.59 (95% CI, 1.26-2.02) for diabetes mellitus or fasting blood glucose ≥7.00 mmol/L, 1.31 (95% CI, 1.02-1.69) for impaired fasting blood glucose (fasting blood glucose, 6.10-6.99 mmol/L), 0.98 (95% CI, 0.78-1.22) for fasting blood glucose 5.60 to 6.09 mmol/L, and 2.04 (95% CI, 1.23-3.38) for hypoglycemia (fasting blood glucose, <4.00 mmol/L), comparing with normal fasting blood glucose 4.00 to 5.59 mmol/L. The results persisted after excluding individuals who used hypoglycemic, aspirin, antihypertensive agents, or anticoagulants, and those with intracerebral hemorrhagic cases occurred in the first 2 years of follow-up.

CONCLUSIONS

In this large community-based cohort, low (<4.0 mmol/L) and high (≥6.1 mmol/L) fasting blood glucose concentrations were associated with higher risk of incident ICH, relative to fasting blood glucose concentrations of 4.00 to 6.09 mmol/L.

Antioxidant effects of epigallocatechin-3-gallate on the aTC1-6 pancreatic alpha cell line

Hypoglycemia is a major barrier to achieving stable metabolic control in patients with diabetes which is a serious clinical concern. With progression of diabetes, the ability of pancreatic α-cells which respond to hypoglycemia becomes impaired; However, it is not clear whether the dysfunctional responses of α-cells during hypoglycemia are related with oxidative stress. In the present study, we investigated whether epigallocatechin-3-gallate (EGCG) has antioxidant potential on pancreatic alpha TC1-6 (αTC1-6) cell lines and protect the normal function of α-cells from H₂O₂ induced oxidative stress. ROS production, cell viability, glucagon secretion, and cell apoptosis were assessed. EGCG reduced ROS production and cell apoptosis, while restored cell viability and glucagon secretion within a particular concentration range. Moreover, EGCG activated Akt signaling and inhibited P38 as well as JNK mitogen-activated protein kinase (MAPK) pathway. Taken together, EGCG prevented αTC1-6 cells from H₂O₂ induced oxidative stress, restored dysfunction of glucagon secretion and inhibited cell apoptosis via the activation of Akt signaling and suppression of P38 and JNK pathway. These results provide rationale for combining the conventional anti-hyperglycemia therapy and antioxidant therapy in order to avert hypoglycemia in clinical treatment of diabetes.

Interdisciplinary approach to compensation of hypoglycemia in diabetic patients with chronic heart failure

Diabetes mellitus is a chronic disease requiring lifelong control with hypoglycemic agents that must demonstrate excellent efficacy and safety profiles. In patients taking glucose-lowering drugs, hypoglycemia is a common cause of death associated with arrhythmias, increased thrombus formation, and specific effects of catecholamines due to sympathoadrenal activation. Focus is now shifting from merely glycemic control to multifactorial approach. In the context of individual drugs and classes, this article reviews interdisciplinary strategies evaluating metabolic effects of drugs for treatment of chronic heart failure (CHF) which can mask characteristic hypoglycemia symptoms. Hypoglycemia unawareness and cardiac autonomic neuropathy are discussed. Data suggesting that hypoglycemia modulates immune response are reviewed. The potential role of gut microbiota in improving health of patients with diabetes and CHF is emphasized. Reports stating that nondiabetic CHF patients can have life-threatening hypoglycemia associated with imbalance of thyroid hormones are discussed. Regular glycemic control based on HbA1c measurements and adequate pharmacotherapy remain the priorities in diabetes management. New antihyperglycemic drugs with safer profiles should be preferred in vulnerable CHF patients. Multidrug interactions must be considered. Emerging therapies with reduced hypoglycemia risk, telemedicine, sensor technologies, and genetic testing predicting hypoglycemia risk may help solving the challenges of hypoglycemia in CHF patients with diabetes. Interdisciplinary work may involve cardiologists, diabetologists/endocrinologists, immunologists, gastroenterologists, microbiologists, nutritionists, imaging specialists, geneticists, telemedicine experts, and other relevant specialists. This review emphasizes that systematic knowledge on pathophysiology of hypoglycemia in diabetic patients with CHF is largely lacking and the gaps in our understanding require further discoveries.

Low glucose induces mitochondrial reactive oxygen species via fatty acid oxidation in bovine aortic endothelial cells

AIMS/INTRODUCTION

Overproduction of reactive oxygen species (ROS) in endothelial cells (ECs) plays a pivotal role in endothelial dysfunction. Mitochondrial ROS (mtROS) is one of the key players in the pathogenesis of diabetic vascular complications. Hypoglycemia is linked to increased ROS production and vascular events; however, the underlying mechanisms remain unclear. In the present study, we aimed to determine whether and how low glucose (LG) mediates mtROS generation in ECs, and to examine the impact of LG-induced mtROS on endothelial dysfunction.

MATERIALS AND METHODS

Metabolomic profiling, cellular oxygen consumption rate, mtROS, endothelial nitric oxide synthase phosphorylation, and the expression of vascular cell adhesion molecule-1 or intercellular adhesion molecule-1 were evaluated in bovine aortic ECs.

RESULTS

We found that LG increased mtROS generation in ECs; which was suppressed by overexpression of manganese superoxide dismutase. Comprehensive metabolic analysis using capillary electrophoresis-mass spectrometry and oxygen consumption rate assessment showed that the pathway from fatty acid to acetyl-CoA through fatty acid oxidation was upregulated in ECs under LG conditions. In addition, etomoxir, a specific inhibitor of the free fatty acid transporter, decreased LG-induced mtROS production. These results suggested that LG increased mtROS generation through activation of fatty acid oxidation. We further revealed that LG inhibited endothelial nitric oxide synthase phosphorylation, and increased the expression of vascular cell adhesion molecule-1 and intercellular adhesion molecule-1. These effects were suppressed either by overexpression of manganese superoxide dismutase or by treatment with etomoxir.

CONCLUSIONS

The activation of fatty acid oxidation followed by mtROS production could be one of the causes for endothelial dysfunction during hypoglycemia.

Proinflammatory Effects of Hypoglycemia in Humans With or Without Diabetes

Severe hypoglycemic events have been associated with increased cardiovascular mortality in patients with diabetes, which may be explained by hypoglycemia-induced inflammation. We used ex vivo stimulations of peripheral blood mononuclear cells (PBMCs) and monocytes obtained during hyperinsulinemic-euglycemic (5.0 mmol/L)-hypoglycemic (2.6 mmol/L) clamps in 11 healthy participants, 10 patients with type 1 diabetes and normal awareness of hypoglycemia (NAH), and 10 patients with type 1 diabetes and impaired awareness (IAH) to test whether the composition and inflammatory function of immune cells adapt to a more proinflammatory state after hypoglycemia. Hypoglycemia increased leukocyte numbers in healthy control participants and patients with NAH but not in patients with IAH. Leukocytosis strongly correlated with the adrenaline response to hypoglycemia. Ex vivo, PBMCs and monocytes displayed a more robust cytokine response to microbial stimulation after hypoglycemia compared with euglycemia, although it was less pronounced in patients with IAH. Of note, hypoglycemia increased the expression of markers of demargination and inflammation in PBMCs. We conclude that hypoglycemia promotes mobilization of specific leukocyte subsets from the marginal pool and induces proinflammatory functional changes in immune cells. Inflammatory responses were less pronounced in IAH, indicating that counterregulatory hormone responses are key modulators of hypoglycemia-induced proinflammatory effects. Hypoglycemia-induced proinflammatory changes may promote a sustained inflammatory state.

Fear of hypoglycemia: Influence on glycemic variability and self-management behavior in young adults with type 1 diabetes

PURPOSE

The purpose of this study was to examine how fear of hypoglycemia (FOH) is associated with glycemic variability (GV) and self-management behavior in young adults (aged 18-35) with type 1 diabetes (T1DM).

PROCEDURES

Using a prospective repeated-measures design, in 35 young adults, within- and between-person and temporal associations of FOH, specific self-management behaviors, and GV were measured. The data were collected using questionnaires and real-time measures using daily diaries, insulin pump downloads, actigraphy, and continuous glucose monitoring.

FINDINGS

FOH was associated with greater glycemic variability. Significant temporal associations emerged. Concurrent day (glucose SD, p=.011) and previous-evening fear levels were associated with GV (glucose SD, p=.007). FOH was also associated with greater calorie intake (r=.492, p=.003) and less physical activity (light activity, r=-.341, p=.045).

CONCLUSIONS

The significant associations of FOH with GV, dietary patterns, and physical activity provide evidence for FOH as an important psychological factor associated with diabetes care.

The effects of 2 weeks of interval vs continuous walking training on glycaemic control and whole-body oxidative stress in individuals with type 2 diabetes: a controlled, randomised, crossover trial

AIMS/HYPOTHESIS

The aim of this study was to evaluate the effects of oxygen consumption-matched short-term interval walking training (IWT) vs continuous walking training (CWT) on glycaemic control, including glycaemic variability, in individuals with type 2 diabetes. We also assessed whether any training-induced improvements in glycaemic control were associated with systemic oxidative stress levels.

METHODS

Participants (n = 14) with type 2 diabetes completed a crossover trial using three interventions (control intervention [CON], CWT and IWT), each lasting 2 weeks. These were performed in a randomised order (computerised generated randomisation) and separated by washout periods of 4 or 8 weeks after CON or training interventions, respectively. Training included ten supervised treadmill sessions, lasting 60 min/session, and was performed at the research facility. CWT was performed at moderate walking speed (75.6% ± 2.5% of walking peak oxygen consumption [[Formula: see text]]), while IWT was performed as alternating 3 min repetitions at slow (58.9% ± 2.0% [Formula: see text]) and fast (90.0% ± 3.6% [Formula: see text]) walking speed. Before and after each intervention, the following was assessed: 24 h continuous glucose monitoring (CGM) and urinary free 8-iso prostaglandin F_2α (8-iso PGF_2α; a marker for oxidative stress), physical fitness and body composition. Neither participants nor assessors were blinded to the interventions.

RESULTS

No intervention-induced changes were seen in physical fitness or body composition. Compared with baseline, IWT reduced mean glucose levels non-significantly (-0.7 ± 0.3 mmol/l, p = 0.08) and significantly reduced maximum glucose levels (-1.8 ± 0.5 mmol/l, p = 0.04) and mean amplitude of glycaemic excursions (MAGE; -1.7 ± 0.4 mmol/l, p = 0.02), whereas no significant within-group changes were seen with CON or CWT. Although 8-iso PGF_2α was associated with minimum glucose levels at baseline, no change in 8-iso PGF_2α was seen with any intervention, nor were there any associations between changes in 8-iso PGF_2α and changes in glycaemic control (p > 0.05 for all). No adverse effects were observed with any of the interventions.

CONCLUSIONS/INTERPRETATION

Short-term IWT, but not CWT, improves CGM-derived measures of glycaemic control independent of changes in physical fitness and body composition in individuals with type 2 diabetes. Systemic oxidative stress levels are unaffected by short-term walking and changes in oxidative stress levels are not associated with changes in glycaemic control.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02320526 FUNDING : The Centre for Physical Activity Research (CFAS) is supported by a grant from TrygFonden. During the study period, the Centre of Inflammation and Metabolism (CIM) was supported by a grant from the Danish National Research Foundation (DNRF55). The study was further supported by grants from Diabetesforeningen, Augustinusfonden and Krista og Viggo Petersens Fond. CIM/CFAS is a member of the Danish Center for Strategic Research in Type 2 Diabetes (DD2; the Danish Council for Strategic Research, grant no. 09-067009 and 09-075724). MR-L was supported by a post-doctoral grant from the Danish Diabetes Academy supported by the Novo Nordisk Foundation.

Lowest Glucose Variability and Hypoglycemia Are Observed With the Combination of a GLP-1 Receptor Agonist and Basal Insulin (VARIATION Study)

OBJECTIVE

There is a dearth of published literature comparing glucose variability (GV) between different insulin regimens in type 2 diabetes. This cohort study compares GV using continuous glucose monitoring (CGM) in patients with well-controlled type 2 diabetes using four common insulin regimens: basal insulin + oral drugs (BO), basal insulin + glucagon-like peptide 1 receptor agonist (GLP-1 RA) (BGLP), premixed insulin (PM), and basal-bolus insulin (BB).

RESEARCH DESIGN AND METHODS

Consecutive patients from three endocrinology clinics who met study criteria-type 2 diabetes, age 18 to 80 years, BMI ≤ 45 kg/m², stable insulin regimen for a minimum of 6 months, and stable A1C value ≤7.5% (58 mmol/mol) before study enrollment-underwent 6-day masked CGM. Hypoglycemia was defined as a sensor glucose concentration <70 mg/dL on CGM.

RESULTS

A total of 160 patients with comparable baseline characteristics formed four equal insulin regimen cohorts. The daily glucose SD (the primary outcome) was significantly lower in the BGLP cohort versus the BO, PM, and BB cohorts (P = 0.03, P = 0.01, and P < 0.01, respectively), and remained so after adjusting for age, BMI, type 2 diabetes duration, and A1C. Similarly, daily hypoglycemia outcomes on CGM were least for the BGLP cohort.

CONCLUSIONS

The lowest GV and lowest hypoglycemia were observed in patients using the combination of basal insulin with a GLP-1 RA, supporting the complementary glycemic action of these agents in type 2 diabetes. These observed benefits in GV and hypoglycemia may contribute to the cardiovascular outcome reduction seen with GLP-1 RA therapy and should be investigated further.

Glucose homeostasis, nutrition and infections during critical illness

Critical illness is a complex life-threatening disease characterized by profound endocrine and metabolic alterations and by a dysregulated immune response, together contributing to the susceptibility for nosocomial infections and sepsis. Hitherto, two metabolic strategies have been shown to reduce nosocomial infections in the critically ill, namely tight blood glucose control and early macronutrient restriction. Hyperglycaemia, as part of the endocrine-metabolic responses to stress, is present in virtually all critically ill patients and is associated with poor outcome. Maintaining normoglycaemia with intensive insulin therapy has been shown to reduce morbidity and mortality, by prevention of vital organ dysfunction and prevention of new severe infections. The favourable effects of this intervention were attributed to the avoidance of glucose toxicity and mitochondrial damage in cells of vital organs and in immune cells. Hyperglycaemia was shown to impair macrophage phagocytosis and oxidative burst capacity, which could be restored by targeting normoglycaemia. An anti-inflammatory effect of insulin may have contributed to prevention of collateral damage to host tissues. Not using parenteral nutrition during the first week in intensive care units, and so accepting a large macronutrient deficit, also resulted in fewer secondary infections, less weakness and accelerated recovery. This was at least partially explained by a suppressive effect of early parenteral nutrition on autophagic processes, which may have jeopardized crucial antimicrobial defences and cell damage removal. The beneficial impact of these two metabolic strategies has opened a new field of research that will allow us to improve the understanding of the determinants of nosocomial infections, sepsis and organ failure in the critically ill.

Understanding the impact of hypoglycemia on the cardiovascular system

INTRODUCTION

Hypoglycemia occurs commonly in insulin requiring individuals with either Type 1 or Type 2 Diabetes.

AREAS COVERED

This article will review recent information on the pro-inflammatory and pro-atherothrombotic effects of hypoglycemia. Additionally, effects of hypoglycemia on arrhythmogenic potential and arterial endothelial dysfunction will be discussed. Effects of hypoglycemia on cardiovascular morbidity and mortality from large clinical studies in Type 1 and Type 2 DM will also be reviewed.

EXPERT COMMENTARY

The relative and absolute risk of severe hypoglycemia leading to death and serious adverse events in both cardiovascular and other organ systems has been highlighted following the publication of recent large clinical trials focused on glucose control and outcomes. It would be helpful if future studies could develop broader end points to include minor and moderate hypoglycemia as well as more robust methods for capturing hypoglycemia contemporaneously with adverse events. In addition, perhaps consideration of including hypoglycemia as a primary outcome, may help identify the possible cause and effect of hypoglycemia on cardiovascular morbidity and mortality.

Dynamin-related protein 1 mediates low glucose-induced endothelial dysfunction in human arterioles

Intensive glycemic regulation has resulted in an increased incidence of hypoglycemia. Hypoglycemic burden correlates with adverse cardiovascular complications and contributes acutely and chronically to endothelial dysfunction. Prior data indicate that mitochondrial dysfunction contributes to hypoglycemia-induced endothelial dysfunction, but the mechanisms behind this linkage remain unknown. We attempt to determine whether clinically relevant low-glucose (LG) exposures acutely induce endothelial dysfunction through activation of the mitochondrial fission process. Characterization of mitochondrial morphology was carried out in cultured endothelial cells by using confocal microscopy. Isolated human arterioles were used to explore the effect LG-induced mitochondrial fission has on the formation of detrimental reactive oxygen species (ROS), bioavailability of nitric oxide (NO), and endothelial-dependent vascular relaxation. Fluorescence microscopy was employed to visualize changes in mitochondrial ROS and NO levels and videomicroscopy applied to measure vasodilation response. Pharmacological disruption of the profission protein Drp1 with Mdivi-1 during LG exposure reduced mitochondrial fragmentation among vascular endothelial cells (LG: 0.469; LG+Mdivi-1: 0.276; P = 0.003), prevented formation of vascular ROS (LG: 2.036; LG+Mdivi-1: 1.774; P = 0.005), increased the presence of NO (LG: 1.352; LG+Mdivi-1: 1.502; P = 0.048), and improved vascular dilation response to acetylcholine (LG: 31.6%; LG+Mdivi-1; 78.5% at maximum dose; P < 0.001). Additionally, decreased expression of Drp1 via siRNA knockdown during LG conditions also improved vascular relaxation. Exposure to LG imparts endothelial dysfunction coupled with altered mitochondrial phenotypes among isolated human arterioles. Disruption of Drp1 and subsequent mitochondrial fragmentation events prevents impaired vascular dilation, restores mitochondrial phenotype, and implicates mitochondrial fission as a primary mediator of LG-induced endothelial dysfunction.NEW & NOTEWORTHY Acute low-glucose exposure induces mitochondrial fragmentation in endothelial cells via Drp1 and is associated with impaired endothelial function in human arterioles. Targeting of Drp1 prevents fragmentation, improves vasofunction, and may provide a therapeutic target for improving cardiovascular complications among diabetics.Listen to this article's corresponding podcast @ http://ajpheart.podbean.com/e/mitochondrial-dynamics-impact-endothelial-function/.

Visit-to-visit variation of fasting plasma glucose is a predictor of hip fracture in older persons with type 2 diabetes: the Taiwan Diabetes Study

We investigated the association between fasting plasma glucose variability (FPG-CV) and the risk of hip fracture in elderly diabetic patients. Our finding showed a temporal association between FPG-CV and hip fracture as patients categorized as FPG-CV greater than 25.4 % showed an increased risk in hip fractures.

INTRODUCTION

Hip fracture is a major health burden in the population and is associated with high rates of mortality and morbidity especially in elderly. It is evident that diabetes mellitus is a risk factor of osteoporosis which is a significant risk factor of hip fracture. However, epidemiological studies exploring the risks of hip fracture among type 2 diabetic patients are limited.

METHODS

A retrospective study of 26,501 ethnic Chinese older persons enrolled in the National Diabetes Care Management program in Taiwan was conducted; related factors were analyzed with extended Cox proportional hazards regression models to competing risk data on hip fracture incidence.

RESULTS

The results show a temporal association between FPG-CV and hip fracture as patients categorized as FPG-CV greater than 25.4 % showed an increased risk in hip fractures, confirming a linear relationship between the two. After multivariate adjustment, the risk of hip fracture increased among patients with FPG-CV of 25.4-42.3 % and >42.3 % compared with patients with FPG-CV of ≦ 14.3 % (hazard ratio, 1.35; 95 % confidence interval 1.14-1.60 and 1.27; 1.07-1.52, respectively). Significant linear trends among various FPG-CV were observed.

CONCLUSIONS

Thus, the present study demonstrated the importance of glucose stability for fracture prevention in older persons with type 2 diabetes. Future studies should be conducted to explore whether reduction in glucose oscillation in older adults with diabetes mellitus can reduce the risk of hip fracture.

Effects of equivalent sympathetic activation during hypoglycemia on endothelial function and pro-atherothrombotic balance in healthy individuals and obese standard treated type 2 diabetes

OBJECTIVE

Recent studies in type 2 diabetes have reported an association between hypoglycemia and severe cardiovascular adverse events, which are relatively increased in standard versus intensively treated individuals. The aim of this study was to determine the effects of equivalent sympathetic nervous system (SNS) activity during moderate hypoglycemia on in-vivo endothelial function, pro-inflammatory, pro-atherothrombotic, and pro-coagulant responses in healthy and standard treated type 2 diabetes individuals.

RESEARCH DESIGN AND METHODS

Eleven type 2 diabetes and 16 healthy individuals participated in single 2day studies. Day 1 involved a 2h hyperinsulinemic/euglycemic clamp and day 2, a 2h hyperinsulinemic/hypoglycemic clamp of 3.2±1mmol/L in type 2 diabetes and (2.9±0.1mmol/L) in healthy individuals.

RESULTS

ICAM-1, VCAM-1, P-selectin, PAI-1, VEGF and endothelin-1 (ET-1) fell during hyperinsulinemic euglycemia but increased during hypoglycemia in type 2 diabetes and healthy individuals. Epinephrine and norepinephrine levels were equivalent during hypoglycemia in type 2 DM and healthy individuals. However, despite similar SNS drive but milder and hypoglycemia there were greater ICAM-1, VCAM-1, PAI-1, VEGF and ET-1 responses in the type 2 diabetes group. Endogenous and exogenous nitric oxide mediated arterial vasodilation were also impaired only during hypoglycemia in type 2 diabetes.

CONCLUSION

We conclude that, milder hypoglycemia but equivalent SNS activation results in more diffuse endothelial dysfunction and a greater pro-inflammatory, pro-atherothrombotic and pro-coagulant state in standard treated type 2 diabetes as compared to healthy individuals.

Nrf2-Mediated Neuroprotection Against Recurrent Hypoglycemia Is Insufficient to Prevent Cognitive Impairment in a Rodent Model of Type 1 Diabetes

It remains uncertain whether recurrent nonsevere hypoglycemia (Hypo) results in long-term cognitive impairment in type 1 diabetes (T1D). This study tested the hypothesis that specifically in the T1D state, Hypo leads to cognitive impairment via a pathological response to oxidative stress. Wild-type (Control) and nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) null mice were studied. Eight groups of mice (Control and Nrf2(-/-) ± T1D and ± Hypo) were subject to recurrent, twice-weekly, insulin or saline injections over 4 weeks, after which cognitive function was assessed and brain tissue analyzed. Recurrent moderate hypoglycemia in T1D, but not Control, mice significantly impaired cognitive performance, and this was associated with hippocampal oxidative damage and inflammation despite an enhanced expression of Nrf2 and its target genes Hmox1 and Nqo1 In Nrf2(-/-) mice, both T1D and Hypo independently resulted in impaired cognitive performance, and this was associated with oxidative cell damage and marked inflammation. Together, these data suggest that Hypo induces an Nrf2-dependent antioxidant response in the hippocampus, which counteracts oxidative damage. However, in T1D, this neuroprotective mechanism is insufficient to prevent neuronal oxidative damage, resulting in chronic deficits in working and long-term memory.

Update on the treatment of type 2 diabetes mellitus

To achieve good metabolic control in diabetes and keep long term, a combination of changes in lifestyle and pharmacological treatment is necessary. Achieving near-normal glycated hemoglobin significantly, decreases risk of macrovascular and microvascular complications. At present there are different treatments, both oral and injectable, available for the treatment of type 2 diabetes mellitus (T2DM). Treatment algorithms designed to reduce the development or progression of the complications of diabetes emphasizes the need for good glycaemic control. The aim of this review is to perform an update on the benefits and limitations of different drugs, both current and future, for the treatment of T2DM. Initial intervention should focus on lifestyle changes. Moreover, changes in lifestyle have proven to be beneficial, but for many patients is a complication keep long term. Physicians should be familiar with the different types of existing drugs for the treatment of diabetes and select the most effective, safe and better tolerated by patients. Metformin remains the first choice of treatment for most patients. Other alternative or second-line treatment options should be individualized depending on the characteristics of each patient. This article reviews the treatments available for patients with T2DM, with an emphasis on agents introduced within the last decade.

The evolving frontier of diabetes therapy: The renaissance of glycemology

It was previously proposed that diabetes could be a "cardiovascular disease". This concept was based on evidence showing that controlling hypertension and dyslipidemia could be more effective than controlling hyperglycemia. At that time it was concluded that the real need to focus on reaching optimal glycemic control had lost its appeal. However, the concept of glycemic control was strictly correlated to levels of glycated hemoglobin (HbA1c), the integrated measure of mean glycemia over the previous 2-3months, while recent evidence suggests that the concept of hyperglycemia has profoundly changed, and it is more appropriate to speak of different kinds or aspects of hyperglycemia. A modern, updated approach to glycemic control in people with diabetes, in fact, must focus not only on reaching and maintaining optimal HbA1c levels as soon as possible, but to obtain this result by reducing postprandial hyperglycemia and glycemic variability, while avoiding hypoglycemia.

Treatment of Hypoglycemia in Adult Patients with Type 1 Diabetes: An Observational Study

OBJECTIVES

1) To characterize the nutritional treatment of hypoglycemia in adult patients with type 1 diabetes mellitus and 2) to compare the characteristics of participants who follow the recommendations with the characteristics of those who do not.

METHODS

A total of 121 adults with type 1 diabetes were included in this cross-sectional analysis. Participants completed a food record and a glycemia and insulin doses logbook to collect data on mild to moderate hypoglycemic events (glycemia <4.0 mmol/L or 4.0 to 5.0 mmol/L with symptoms) and their treatments over a 2-day period. Participants were identified as overcorrecting if they consumed, within 15 minutes after the episode, >20g of carbohydrates for correction. Self-administered questionnaires about fear of hypoglycemia were completed, and cardiometabolic profile variables were measured (glycated hemoglobin, blood pressure, lipid profile and body mass indexes).

RESULTS

Of the 121 participants, 94 (78%) reported at least 1 hypoglycemic event, for a total of 271 events (2.2±2.1 episodes per patient). Of these events, 64% were treated within 15 minutes, and they were treated primarily with fruit juice or sweet beverages (39%) or mixed snacks (29%). Average carbohydrate intake for treatment was 32±24 grams. Of the participants, 73% overtreated their episodes. They were significantly younger and had greater fear of hypoglycemia than those who treated the episodes adequately. No difference was observed for cardiometabolic variables.

CONCLUSIONS

The majority of patients in our cohort overtreated their hypoglycemic episodes. These results suggest that hypoglycemia-correction education needs to be reinforced.

"Inflammaging" as a Druggable Target: A Senescence-Associated Secretory Phenotype-Centered View of Type 2 Diabetes

Aging is a complex phenomenon driven by a variety of molecular alterations. A relevant feature of aging is chronic low-grade inflammation, termed “inflammaging.” In type 2 diabetes mellitus (T2DM), many elements of aging appear earlier or are overrepresented, including consistent inflammaging. T2DM patients have an increased death rate, associated with an incremented inflammatory score. The source of this inflammation is debated. Recently, the senescence-associated secretory phenotype (SASP) has been proposed as the main origin of inflammaging in both aging and T2DM. Different pathogenic mechanisms linked to T2DM progression and complications development have been linked to senescence and SASP, that is, oxidative stress and endoplasmic reticulum (ER) stress. Here we review the latest data connecting oxidative and ER stress with the SASP in the context of aging and T2DM, with emphasis on endothelial cells (ECs) and endothelial dysfunction. Moreover, since current medical practice is insufficient to completely suppress the increased death rate of diabetic patients, we propose a SASP-centered view of T2DM as a futuristic therapeutic option, possibly opening new prospects by moving the attention from one-organ studies of diabetes complications to a wider targeting of the aging process.

Clinical implications of oxidative stress and potential role of natural antioxidants in diabetic vascular complications

AIMS

The possible link between hyperglycaemia-induced oxidative stress (OxS) and diabetic complications is suggested by many in vitro studies. However, not much attention has been paid to the clinical evidence supporting this hypothesis, as well as to their possible therapeutic implications.

DATA SYNTHESIS

Some prospective studies show a direct correlation between an increase in OxS biomarkers and the appearance of diabetes complications. This is consistent with the evidence that any acute increase of glycaemia, particularly post-prandial, and hypoglycaemia causes endothelial dysfunction and inflammation, through the generation of an OxS. However, the detection of free radicals is difficult as they are highly reactive molecules with a short half-life. Instead, the metabolites of OxS are measured. Interventional trials with supplemented antioxidants have failed to show any beneficial effects. Conversely, natural foods show very promising results.

CONCLUSIONS

The "new antioxidant" approach includes the possibility of controlling free radical production and increasing intracellular antioxidant defence, a concept different from the old one, when antioxidant activities implied scavenging the free radicals already produced. A synergistic action in this respect could convincingly be obtained with a balanced 'Mediterranean Diet' (MedD) type. Early intensive glucose control is still the best strategy to avoid OxS and its associated diabetes complications.

Nitrones reverse hyperglycemia-induced endothelial dysfunction in bovine aortic endothelial cells

Hyperglycemia has been implicated in the development of endothelial dysfunction through heightened ROS production. Since nitrones reverse endothelial nitric oxide synthase (eNOS) dysfunction, increase antioxidant enzyme activity, and suppress pro-apoptotic signaling pathway and mitochondrial dysfunction from ROS-induced toxicity, the objective of this study was to determine whether nitrone spin traps DMPO, PBN and PBN-LA were effective at duplicating these effects and improving glucose uptake in an in vitro model of hyperglycemia-induced dysfunction using bovine aortic endothelial cells (BAEC). BAEC were cultured in DMEM medium with low (5.5mM glucose, LG) or high glucose (50mM, HG) for 14 days to model in vivo hyperglycemia as experienced in humans with metabolic disease. Improvements in cell viability, intracellular oxidative stress, NO and tetrahydrobiopterin (BH4)​ levels, mitochondrial membrane potential, glucose transport, and activity of antioxidant enzymes were measured from single treatment of BAEC with nitrones for 24h after hyperglycemia. Chronic hyperglycemia significantly increased intracellular ROS by 50%, decreased cell viability by 25%, reduced NO bioavailability by 50%, and decreased (BH4) levels by 15% thereby decreasing NO production. Intracellular glucose transport and superoxide dismutase (SOD) activity were also decreased by 50% and 25% respectively. Nitrone (PBN and DMPO, 50 μM) treatment of BAEC grown in hyperglycemic conditions resulted in the normalization of outcome measures except for SOD and catalase activities. Our findings demonstrate that the nitrones reverse the deleterious effects of hyperglycemia in BAEC. We believe that in vivo testing of these nitrone compounds in models of cardiometabolic disease is warranted.

In vivo studies on hepato-renal impairments in freshwater fish Cyprinus carpio following exposure to sublethal concentrations of sodium cyanide

Reactive oxygen species is an inevitable composite of aerobic systems that could channelize their lethality by imparting oxidative stress under a stressful environment. Cyanide is an important environmental toxicant that could be responsible in the resulting detrimental health issues of aquatic fauna. The present effort investigates the possibilities of hepato-renal damage in freshwater fish Cyprinus carpio following exposure to sublethal concentrations of sodium cyanide (NaCN). Fish were exposed to 0.1 mg/L of NaCN for 10 days (E1) and 20 days (E2) and were further subjected to recovery for 14 days (R) in NaCN-free medium. Liver tissue exhibited a significant decline in activity of catalase, superoxide dismutase, glutathione peroxidase, and glutathione S-transferase enzymes in exposed fish, unlike in control (C). Subsequent levels of lipid peroxidation elevation at 'E1' and 'E2' suggested oxidative damage to hepatocytes. This was further confirmed through a histopathological evaluation which indicated important findings like lymphocytic infiltration and necrosis in liver and tubular and glomerular degeneration in renal organ. The investigation suggests biochemical and histopathological alterations in fish following exposure to NaCN. Nevertheless, fish upon the recovery period were known to exhibit incomplete recuperation which was indicated by partial restoration tendencies under biochemical and histopathological factions. The study clearly implicated the role of NaCN in emphasizing its toxicity to C. carpio, further suggesting lack of recovery transition at a limited tenure of 14 days. The study might contribute in the course of regulatory surveillance and monitoring of aquatic bodies and may also reflect the possibilities of NaCN contamination during aquaculture practices. Graphical Abstract ᅟ.

The Impact of Hypoglycemia on the Cardiovascular System: Physiology and Pathophysiology

Intensive glycemic control may increase cardiovascular (CV) risk and mortality due to hypoglycemia. The pathophysiology of glucose counter-regulation in patients with type 1 or type 2 diabetes for over 15 years is characterized by impairment of the defense mechanisms against hypoglycemia. Hypoglycemia causes pronounced physiological and pathophysiological effects on the CV system as consequences of autonomic system activation and counter regulatory hormones release. These effects provoke a series of hemodynamic changes that include an increase in heart rate and peripheral systolic blood pressure, a decrease in central blood pressure, reduced peripheral arterial resistance, and increased myocardial contractility and cardiac output. Cardiac electrophysiological changes including flattening or inversion of T waves, QT prolongation, and ST segment depression were observed in both insulin-induced and spontaneous hypoglycemia. Sympathoadrenal activation is the main cause of these changes through mechanisms that involve, but are not limited to, catecholamine-mediated hypokalemia. Hypoglycemia is also involved in platelet activation. There is growing concern about the long-term effects of hypoglycemia, especially as related to inflammation and atherogenesis.

Sickle Cell Trait Worsens Oxidative Stress, Abnormal Blood Rheology, and Vascular Dysfunction in Type 2 Diabetes

OBJECTIVE

It is predicted that Africa will have the greatest increase in the number of patients with type 2 diabetes mellitus (T2DM) within the next decade. T2DM patients are at risk for cardiovascular disorders. In Sub-Saharan African countries, sickle cell trait (SCT) is frequent. Despite the presence of modest abnormalities in hemorheology and oxidative stress, SCT is generally considered a benign condition. Little is known about vascular function in SCT, although recent studies demonstrated an increased risk of cardiovascular disorders, including venous thromboembolism, stroke, and chronic kidney disease. We hypothesized that SCT could accentuate the vascular dysfunction observed in T2DM.

RESEARCH DESIGN AND METHODS

The current study, conducted in Senegal, compared vascular function, hemorheological profile, and biomarkers of oxidative stress, inflammation, and nitric oxide metabolism in healthy individuals (CONT), subjects with T2DM or SCT, and patients with both T2DM and SCT (T2DM-SCT).

RESULTS

Flow-mediated dilation was blunted in individuals with T2DM, SCT, and T2DM-SCT compared with CONT, with vascular dysfunction being most pronounced in the latter group. Carotid-femoral pulse wave velocity measurements demonstrated increased arterial stiffness in T2DM-SCT. Oxidative stress, advanced glycation end products, and inflammation (interleukin-1β) were greater in patients with T2DM-SCT compared with the other groups. Blood viscosity was higher in individuals with TD2M, SCT carriers, and individuals with T2DM-SCT, and the values were further increased in the latter group.

CONCLUSIONS

Our results demonstrate severe biological abnormalities and marked vascular dysfunction in patients with both T2DM and SCT. SCT should be viewed as a risk factor for further cardiovascular disorders in individuals with T2DM.

Effects of Acute and Antecedent Hypoglycemia on Endothelial Function and Markers of Atherothrombotic Balance in Healthy Humans

The aim of this study was to determine the effects of single and repeated episodes of clamped hypoglycemia on fibrinolytic balance, proinflammatory biomarkers, proatherothrombotic mechanisms, and endothelial function. Twenty healthy individuals (12 male and 8 female) were studied during separate 2-day randomized protocols. Day 1 consisted of either two 2-h hyperinsulinemic (812 ± 50 pmol/L)-euglycemic (5 ± 0.1 mmol/L) or hyperinsulinemic (812 ± 50 pmol/L)-hypoglycemic (2.9 ± 0.1 mmol/L) clamps. Day 2 consisted of a single 2-h hyperinsulinemic-hypoglycemic clamp. Two-dimensional Doppler ultrasound was used to determine brachial arterial endothelial function. Plasminogen activator inhibitor 1, vascular cell adhesion molecule-1, intracellular adhesion molecule-1, E-selectin, P-selectin, TAT (thrombin/antithrombin complex), tumor necrosis factor-α, and interleukin-6 responses were increased (P < 0.05) during single or repeated hypoglycemia compared with euglycemia. Endogenous and exogenous nitric oxide (NO)-mediated vasodilation were both impaired by repeated hypoglycemia. Neuroendocrine and autonomic nervous system (ANS) responses were also blunted by repeated hypoglycemia (P < 0.05). In summary, acute moderate hypoglycemia impairs fibrinolytic balance; increases proinflammatory responses, platelet activation, and coagulation biomarkers; and reduces NO-mediated endothelial function in healthy individuals. Repeated episodes of hypoglycemia further impair vascular function by additionally reducing exogenously NO-mediated endothelial function and increasing coagulation biomarkers. We conclude that despite reduced neuroendocrine and ANS responses, antecedent hypoglycemia results in greater endothelial dysfunction and an increased proatherothrombotic state compared with a single acute episode of hypoglycemia.

Extreme Levels of HbA1c Increase Incident ESRD Risk in Chinese Patients with Type 2 Diabetes: Competing Risk Analysis in National Cohort of Taiwan Diabetes Study

Background

Whether HbA1c is a predictor of end-stage renal disease (ESRD) in type 2 diabetes patients remains unclear. This study evaluated relationship between HbA1c and ESRD in Chinese patients with type 2 diabetes.

Methods

Patients aged ≥ 30 years who were free of ESRD (n = 51 681) were included from National Diabetes Care Management Program from 2002–2003. Extended Cox proportional hazard model with competing risk of death served to evaluate association between HbA1c level and ESRD.

Results

A total of 2613 (5.06%) people developed ESRD during a follow-up period of 8.1 years. Overall incidence rate of ESRD was 6.26 per 1000 person-years. Patients with high levels of HbA1c had a high incidence rate of ESRD, from 4.29 for HbA1c of  6.0%–6.9% to 10.33 for HbA1c ≥ 10.0% per 1000 person-years. Patients with HbA1c < 6.0% particularly had a slightly higher ESRD incidence (4.34 per 1000 person-years) than those with HbA1c  of 6.0%–6.9%. A J-shaped relationship between HbA1c level and ESRD risk was observed. After adjustment, patients with HbA1c < 6.0% and ≥ 10.0% exhibited an increased risk of ESRD (HR: 1.99, 95% CI: 1.62–2.44; HR: 4.42, 95% CI: 3.80–5.14, respectively) compared with those with HbA1c of 6.0%–6.9%.

Conclusions

Diabetes care has focused on preventing hyperglycemia, but not hypoglycemia. Our study revealed that HbA1c level ≥ 7.0% was linked with increased ESRD risk in type 2 diabetes patients, and that HbA1c < 6.0% also had the potential to increase ESRD risk. Our study provides epidemiological evidence that appropriate glycemic control is essential for diabetes care to meet HbA1c targets and improve outcomes without increasing the risk to this population. Clinicians need to pay attention to HbA1c results on diabetic nephropathy.

Hypoglycemia in Patients with Diabetes and Renal Disease

This article summarizes our current knowledge of the epidemiology, pathogenesis, and morbidity of hypoglycemia in patients with diabetic kidney disease and reviews therapeutic limitations in this situation.

Continuous subcutaneous insulin infusion in patients with type 2 diabetes: a cohort study to establish the relationship between glucose control and plasma oxidized low density lipoprotein

BACKGROUND

Oxidative stress is a detrimental feature of diabetes implicated in the progression of the disease and its complications. The relationship between insulin therapy and oxidative stress is complex. This study tested the hypothesis that improved glucose control, rather than insulin dose, is central to reduced oxidative stress in patients with type 2 diabetes following continuous subcutaneous insulin infusion (CSII).

METHODS

In this 16-week, multicenter study, 54 CSII-naïve patients with type 2 diabetes (age 57 ± 10 years, HbA1c 69 ± 15 mmol/mol [8.5 ± 1.4%], diabetes duration 13 ± 6 years) treated with either oral antidiabetic agents (OAD) alone (n = 17), basal insulin ± OAD (n = 17), or multiple daily injections (MDI) ± OAD (n = 20) were the evaluable group. Diabetes medications except metformin were discontinued, and 16 weeks of CSII was initiated. Insulin dose was titrated to achieve optimal glycemic control. A plasma marker of oxidative stress relevant to cardiovascular disease (oxidized low density lipoprotein [ox-LDL]) was assessed at baseline and week 16.

RESULTS

CSII improved glycemic control (HbA1c -13 ± 2 mmol/mol [-1.2 ± 0.2%]; fasting glucose -36.6 ± 8.4 mg/dL; mean glucose excursion -23.2 ± 6.5 mg/dL, mean ± SE; all P < .001) and reduced ox-LDL (-10.5%; P < .05). The antioxidant effect was cohort-independent (P > .05), but was significantly more pronounced in patients on statins (P = .019). The effect of CSII was more closely correlated to improvements in glucose excursion (P = .013) than to insulin dose (P > .05) or reduction in HbA1c (P > .05).

CONCLUSIONS

CSII induces depression of plasma ox-LDL associated with change in glucose control, rather than with change in insulin dose. The effect is augmented in patients receiving statins.

Hypoglycemia in Type 2 Diabetes--More Common Than You Think: A Continuous Glucose Monitoring Study

BACKGROUND

Hypoglycemia is often the limiting factor for intensive glucose control in diabetes management, however its actual prevalence in type 2 diabetes (T2DM) is not well documented.

METHODOLOGY

A total of 108 patients with T2DM wore a continuous glucose monitoring system (CGMS) for 5 days. Rates and patterns of hypoglycemia and glycemic variability (GV) were calculated. Patient and medication factors were correlated with rates, timing, and severity of hypoglycemia.

RESULTS

Of the patients, 49.1% had at least 1 hypoglycemic episode (mean 1.74 episodes/patient/ 5 days of CGMS) and 75% of those patients experienced at least 1 asymptomatic hypoglycemic episode. There was no significant difference in the frequency of daytime versus nocturnal hypoglycemia. Hypoglycemia was more frequent in individuals on insulin (alone or in combination) (P = .02) and those on oral hypoglycemic agents (P < .001) compared to noninsulin secretagogues. CGMS analysis resulted in treatment modifications in 64% of the patients. T2DM patients on insulin exhibited higher glycemic variability (GV) scores (2.3 ± 0.6) as compared to those on oral medications (1.8 ± 0.7, P = .017).

CONCLUSIONS

CGMS can provide rich data that show glucose excursions in diabetes patients throughout the day. Consequently, unwarranted onset of hypo- and hyperglycemic events can be detected, intervened, and prevented by using CGMS. Hypoglycemia was frequently unrecognized by the patients in this study (75%), which increases their potential risk of significant adverse events. Incorporation of CGMS into the routine management of T2DM would increase the detection and self-awareness of hypoglycemia resulting in safer and potentially better overall control.

Increased glycemic variability and decrease of the postprandial glucose contribution to HbA1c in obese subjects across the glycemic continuum from normal glycemia to first time diagnosed diabetes

OBJECTIVE

The contribution of postprandial glycemia (PPG) to hyperglycemia has been shown to decrease as HbA1c increased in type 2 diabetic patients. This study aimed at examining, in a series of overweight/obese patients without known glycemic disorder, the contribution of PPG to a "relative" hyperglycemia (glucose values≥5.5 mmol/L) and the presence of glycemic variability according to HbA1c levels.

METHODS

Seventy overweight/obese inpatients (body mass index 35.2±6.8 kg/m2) without known glycemic disorder were included. Participants were classified according to an oral glucose tolerance test (according to the American Diabetes Association criteria) as patients with normoglycemia (n=33), with intermediate hyperglycemia (n=24) or diabetes (n=13). They were separated into HbA1c quartiles (Q1 to Q4). A 24 hour continuous glucose monitoring was used under a 1800 kcal diet and minimal physical activity. We assessed PPG contribution (3 hour period after each meal) to the "relative" 24 hour hyperglycemia (glucose values ≥5.5 mmol/L); the remaining time was considered as the fasting/post-absorptive period.

RESULTS

HbA1c range was from 5.1% to 7.4% (32 to 57 mmol/mmol). From the lowest to the highest HbA1c quartile, the area under the curve (AUC) for the "relative" hyperglycemia presented a 17-fold increase for the fasting/post-absorptive (p<0.001) period and a 7-fold increase postprandially (p<0.001). The percent of PPG contribution to the "relative" hyperglycemia was calculated with the following formula [100×(postprandial 3 hour AUC-3 h AUC for a constant 5.5 mmol/L glycemia)/(total 24 h AUC-24 h AUC for constant 5. 5 mmol/L glycemia)] and decreased from Q1 to Q4 of HbA1c (81.2%, 66%, 65.8%, 57%; p<0.001). Increasing HbA1c quartiles were associated with higher daily mean blood glucose level (p<0.001) and higher levels of daily glucose variability indices, including mean amplitude of glycemic excursions (p<0.01).

CONCLUSIONS

In overweight/obese patients, HbA1c was associated with lower PPG contribution to "relative" hyperglycemia and greater glycemic variability. The present findings support the importance of postprandial period in glycemic exposure even before the appearance of diabetes.