Effects of acute insulin-induced hypoglycemia on indices of inflammation: putative mechanism for aggravating vascular disease in diabetes

Estimating risk of consequences following hypoglycaemia exposure using the Hypo-RESOLVE cohort: a secondary analysis of pooled data from insulin clinical trials

AIMS/HYPOTHESIS

Whether hypoglycaemia increases the risk of other adverse outcomes in diabetes remains controversial, especially for hypoglycaemia episodes not requiring assistance from another person. An objective of the Hypoglycaemia REdefining SOLutions for better liVEs (Hypo-RESOLVE) project was to create and use a dataset of pooled clinical trials in people with type 1 or type 2 diabetes to examine the association of exposure to all hypoglycaemia episodes across the range of severity with incident event outcomes: death, CVD, neuropathy, kidney disease, retinal disorders and depression. We also examined the change in continuous outcomes that occurred following a hypoglycaemia episode: change in eGFR, HbA1c, blood glucose, blood glucose variability and weight.

METHODS

Data from 84 trials with 39,373 participants were pooled. For event outcomes, time-updated Cox regression models adjusted for age, sex, diabetes duration and HbA1c were fitted to assess association between: (1) outcome and cumulative exposure to hypoglycaemia episodes; and (2) outcomes where an acute effect might be expected (i.e. death, acute CVD, retinal disorders) and any hypoglycaemia exposure within the last 10 days. Exposures to any hypoglycaemia episode and to episodes of given severity (levels 1, 2 and 3) were examined. Further adjustment was then made for a wider set of potential confounders. The within-person change in continuous outcomes was also summarised (median of 40.4 weeks for type 1 diabetes and 26 weeks for type 2 diabetes). Analyses were conducted separately by type of diabetes.

RESULTS

The maximally adjusted association analysis for type 1 diabetes found that cumulative exposure to hypoglycaemia episodes of any level was associated with higher risks of neuropathy, kidney disease, retinal disorders and depression, with risk ratios ranging from 1.55 (p=0.002) to 2.81 (p=0.002). Associations of a similar direction were found when level 1 episodes were examined separately but were significant for depression only. For type 2 diabetes cumulative exposure to hypoglycaemia episodes of any level was associated with higher risks of death, acute CVD, kidney disease, retinal disorders and depression, with risk ratios ranging from 2.35 (p<0.0001) to 3.00 (p<0.0001). These associations remained significant when level 1 episodes were examined separately. There was evidence of an association between hypoglycaemia episodes of any kind in the previous 10 days and death, acute CVD and retinal disorders in both type 1 and type 2 diabetes, with rate ratios ranging from 1.32 (p=0.017) to 2.68 (p<0.0001). These associations varied in magnitude and significance when examined separately by hypoglycaemia level. Within the range of hypoglycaemia defined by levels 1, 2 and 3, we could not find any evidence of a threshold at which risk of these consequences suddenly became pronounced.

CONCLUSIONS/INTERPRETATION

These data are consistent with hypoglycaemia being associated with an increased risk of adverse events across several body systems in diabetes. These associations are not confined to severe hypoglycaemia requiring assistance.

Association of perioperative glucose profiles assessed by continuous glucose monitoring (CGM) with prognosis in Chinese patients with non-ST-elevation acute coronary syndrome: a cohort study protocol

INTRODUCTION

Non-ST-elevation acute coronary syndrome (NSTE-ACS) remains a significant clinical concern, accounting for over 70% of acute coronary syndrome cases. One well-established risk factor for NSTE-ACS is abnormal glucose metabolism, which is associated with a poor prognosis postpercutaneous coronary intervention. Effective monitoring of blood glucose is crucial in diabetes care, as it helps identify glucose metabolic imbalances, thereby guiding therapeutic strategies and assessing treatment efficacy. Continuous glucose monitoring (CGM) provides comprehensive glucose profiles. Therefore, the study aims to use CGM to track perioperative glucose variations in NSTE-ACS patients and to determine its prognostic implications.

METHODS AND ANALYSIS

This is a multicentre, prospective observational study in a sample of patients (aged >18 years) with NSTE-ACS. A total of 1200 eligible patients will be recruited within 1 year at 6 sites in China. The primary composite endpoint will be determined as major adverse cardiovascular events (MACE) at 3 years. MACE includes all-cause mortality, non-fatal myocardial infarction, non-fatal stroke and target vessel revascularisation. Employing the CGM system, glucose levels will be continuously monitored throughout the perioperative phase. Prespecified cardiovascular analyses included analyses of the components of this composite and outcomes according to CGM-derived glucometrics at baseline.

ETHICS AND DISSEMINATION

This study has received approval from the Medical Research Ethics Committee of The First Affiliated Hospital of the University of Science and Technology of China (No. 2022KY357) and will adhere to the moral, ethical and scientific principles outlined in the Declaration of Helsinki. All participants will provide written informed consent prior to any study-related procedures. Findings from the study will be shared at conferences and published in peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

ChiCT2300069663.

Cardiometabolic Risk Factors among Women with Eating Disorders in Saudi Arabia

Objective

To assess selected cardiometabolic risk factors among Saudi women with eating disorders.

Methods

An epidemiological, cross-sectional study included women aged between 18 and 50 years with eating disorders (EDs). Women with chronic diseases, pregnant, or lactating were excluded. The weight and height were measured for the calculation of the body mass index (BMI). Fasting blood samples were drawn for the analysis of blood sugar, glycated haemoglobin, lipid profile, albumin, haemoglobin, and C-reactive levels. The atherogenic dyslipidemia index (AIP) was also calculated.

Results

Patients (n = 100) were enrolled. Fasting blood glucose levels were critically low among women with anorexia nervosa (AN) and bulimia nervosa (BN) but normal among those with binge eating disorders (BEDs). All women with ED suffered from anaemia based on their haemoglobin levels as well as dyslipidemia, hypoalbuminaemia, and high C-reactive protein levels. Women with AN had low cardiovascular (CV) risks based on their normal AIP values. However, women with BN and BED had intermediate CV risks. On average, women with AN suffered from severe thinness and those with BN had normal BMIs, whereas those with BED were overweight. Women (90%) with BN and BED were overweight and/or obese.

Conclusion

Women with ED had a high risk of cardiovascular diseases defined by their hypoalbuminaemia, dyslipidemia, anaemia, and high AIP levels. Dietitians and psychiatrists are advised to collaborate in assessing the potential risk of having eating disorders to provide counselling sessions to women on healthy balanced diets and their effect on health.

Effect of Hypoglycemia and Rebound Hyperglycemia on Proteomic Cardiovascular Risk Biomarkers

Introduction: Hypoglycemia has been associated with cardiovascular events, and glucose variability has been suggested to be associated with increased cardiovascular risk. Therefore, in this study, we examined the effect on proteomic cardiovascular risk protein markers of (i) mild iatrogenic hypoglycemia and (ii) severe iatrogenic hypoglycemia followed by rebound hyperglycemia. Methods: Two iatrogenic hypoglycemia studies were compared; firstly, mild hypoglycemia in 18 subjects (10 type 2 diabetes (T2D), 8 controls; blood glucose to 2.8 mmoL/L (50 mg/dL) for 1 h), and secondly, severe hypoglycemia in 46 subjects (23 T2D, 23 controls; blood glucose to <2.2 mmoL/L (<40 mg/dL) transiently followed by intravenous glucose reversal giving rebound hyperglycemia). A SOMAscan assay was used to measure 54 of the 92 cardiovascular protein biomarkers that reflect biomarkers involved in inflammation, cellular metabolic processes, cell adhesion, and immune response and complement activation. Results: Baseline to euglycemia showed no change in any of the proteins measured in the T2D cohort. With severe hypoglycemia, the study controls showed an increase in Angiopoietin 1 (ANGPT1) (p < 0.01) and Dickkopf-1 (DKK1) (p < 0.01), but no changes were seen with mild hypoglycemia. In both the mild and severe hypoglycemia studies, at the point of hypoglycemia, T2D subjects showed suppression of Brother of CDO (BOC) (p < 0.01). At 1 h post-hypoglycemia, the changes in ANGPT1, DKK1, and BOC had resolved, with no additional protein biomarker changes despite rebound hyperglycemia from 1.8 ± 0.1 to 12.2 ± 2.0 mmol/L. Conclusions: Proteomic biomarkers of cardiovascular disease showed changes at hypoglycemia that resolved within 1 h following the hypoglycemic event and with no changes following hyperglycemia rebound, suggesting that any cardiovascular risk increase is due to the hypoglycemia and not due to glucose fluctuation per se.

Assessing the impact of body composition, metabolic and oxidative stress parameters on insulin resistance as a prognostic marker for reactive hypoglycemia: a cross-sectional study in overweight, obese, and normal weight individuals

Oxidative stress (OS) plays a pivotal role in the pathogenesis of insulin resistance (IR), particularly in its association with obesity. This study evaluate both the diagnostic and clinical significance of assessing oxidative status in patients affected by overweight and obesity displaying IR, especially with reactive hypoglycemic episodes (RH). A comprehensive examination of OS biomarkers was carried out, encompassing measurements of total oxidative capacity (TOC) and total antioxidant capacity (TAC). Our analysis results reveal noteworthy connections between OS levels and the severity of IR in overweight and obese patients. Moreover, in the study, we demonstrated the diagnostic utility of serum concentrations of TAC and TOC as indicators of the risk of RH, the occurrence of which, even at the stage of overweight, may be associated with increased OS and further development of obesity. Our findings imply that the evaluation of oxidative status could serve as a crucial diagnostic and prognostic tool for patients observed with IR and overweight and obesity. In conclusion, our study underscores the potential utility of assessing oxidative status in the context of IR and highlights the possibility of identifying novel therapeutic targets for the treatment of overweight and obese patients.

Dapagliflozin ameliorated retinal vascular permeability in diabetic retinopathy rats by suppressing inflammatory factors

BACKGROUND

Diabetic retinopathy is a common microvascular complication of diabetes and one of the major causes of blindness in the working-age population. Emerging evidence has elucidated that inflammation drives the key mechanism of diabetes-mediated retinal disturbance. As a new therapeutic drug targeting diabetes, whether dapagliflozin could improve vascular permeability from the perspective of anti-inflammatory effect need to be further explored.

METHODS

Type 2 diabetic retinopathy rat model was established and confirmed by fundus fluorescein angiography (FFA). ELISA detected level of plasma inflammatory factors and C-peptide. HE staining, immunohistochemistry and western blot detected histopathology changes of retina, expression of retinal inflammatory factors and tight junction proteins.

RESULTS

Dapagliflozin exhibited hypoglycemic effect comparable to insulin, but did not affect body weight. By inhibiting expression of inflammatory factors (NLRP3, Caspase-1, IL-18, NF-κB) in diabetic retina and plasma, dapagliflozin reduced damage of retinal tight junction proteins and improved retinal vascular permeability. The anti-inflammatory effect of dapagliflozin was superior to insulin.

CONCLUSIONS

Dapagliflozin improved retinal vascular permeability by reducing diabetic retinal and plasma inflammatory factors. The anti-inflammatory mechanism of dapagliflozin is independent of hypoglycemic effect and superior to insulin.

The impact of prior exposure to hypoglycaemia on the inflammatory response to a subsequent hypoglycaemic episode

BACKGROUND

Hypoglycaemia has been shown to induce a systemic pro-inflammatory response, which may be driven, in part, by the adrenaline response. Prior exposure to hypoglycaemia attenuates counterregulatory hormone responses to subsequent hypoglycaemia, but whether this effect can be extrapolated to the pro-inflammatory response is unclear. Therefore, we investigated the effect of antecedent hypoglycaemia on inflammatory responses to subsequent hypoglycaemia in humans.

METHODS

Healthy participants (n = 32) were recruited and randomised to two 2-h episodes of either hypoglycaemia or normoglycaemia on day 1, followed by a hyperinsulinaemic hypoglycaemic (2.8 ± 0.1 mmol/L) glucose clamp on day 2. During normoglycaemia and hypoglycaemia, and after 24 h, 72 h and 1 week, blood was drawn to determine circulating immune cell composition, phenotype and function, and 93 circulating inflammatory proteins including hs-CRP.

RESULTS

In the group undergoing antecedent hypoglycaemia, the adrenaline response to next-day hypoglycaemia was lower compared to the control group (1.45 ± 1.24 vs 2.68 ± 1.41 nmol/l). In both groups, day 2 hypoglycaemia increased absolute numbers of circulating immune cells, of which lymphocytes and monocytes remained elevated for the whole week. Also, the proportion of pro-inflammatory CD16+-monocytes increased during hypoglycaemia. After ex vivo stimulation, monocytes released more TNF-α and IL-1β, and less IL-10 in response to hypoglycaemia, whereas levels of 19 circulating inflammatory proteins, including hs-CRP, increased for up to 1 week after the hypoglycaemic event. Most of the inflammatory responses were similar in the two groups, except the persistent pro-inflammatory protein changes were partly blunted in the group exposed to antecedent hypoglycaemia. We did not find a correlation between the adrenaline response and the inflammatory responses during hypoglycaemia.

CONCLUSION

Hypoglycaemia induces an acute and persistent pro-inflammatory response at multiple levels that occurs largely, but not completely, independent of prior exposure to hypoglycaemia. Clinical Trial information Clinicaltrials.gov no. NCT03976271 (registered 5 June 2019).

Hypoglycaemia induces a sustained pro-inflammatory response in people with type 1 diabetes and healthy controls

AIM

To determine the duration and the extension of the pro-inflammatory response to hypoglycaemia both in people with type 1 diabetes and healthy controls.

MATERIALS AND METHODS

Adults with type 1 diabetes (n = 47) and matched controls (n = 16) underwent a hyperinsulinaemic-euglycaemic hypoglycaemic (2.8 ± 0.1 mmoL/L [49.9 ± 2.3 mg/dL]) glucose clamp. During euglycaemia, hypoglycaemia, and 1, 3 and 7 days later, blood was drawn to determine immune cell phenotype, monocyte function and circulating inflammatory markers.

RESULTS

Hypoglycaemia increased lymphocyte and monocyte counts, which remained elevated for 1 week. The proportion of CD16+ monocytes increased and the proportion of CD14+ monocytes decreased. During hypoglycaemia, monocytes released more tumour necrosis factor-α and interleukin-1β, and less interleukin-10, after ex vivo stimulation. Hypoglycaemia increased the levels of 19 circulating inflammatory proteins, including high sensitive C-reactive protein, most of which remained elevated for 1 week. The epinephrine peak in response to hypoglycaemia was positively correlated with immune cell number and phenotype, but not with the proteomic response.

CONCLUSIONS

Overall, despite differences in prior exposure to hypoglycaemia, the pattern of the inflammatory responses to hypoglycaemia did not differ between people with type 1 diabetes and healthy controls. In conclusion, hypoglycaemia induces a range of pro-inflammatory responses that are sustained for at least 1 week in people with type 1 diabetes and healthy controls.

Brain Regulation of Cardiac Function during Hypoglycemia

Hypoglycemia occurs frequently in people with type 1 and type 2 diabetes. Hypoglycemia activates the counter-regulatory response. Besides peripheral glucose sensors located in the pancreas, mouth, gastrointestinal tract, portal vein, and carotid body, many brain regions also contain glucose-sensing neurons that detect this fall in glucose. The autonomic nervous system innervates the heart, and during hypoglycemia, can cause many changes. Clinical and animal studies have revealed changes in electrocardiograms during hypoglycemia. Cardiac repolarization defects (QTc prolongation) occur during moderate levels of hypoglycemia. When hypoglycemia is severe, it can be fatal. Cardiac arrhythmias are thought to be the major mediator of sudden death due to severe hypoglycemia. Both the sympathetic and parasympathetic nervous systems of the brain have been implicated in regulating these arrhythmias. Besides cardiac arrhythmias, hypoglycemia can have profound changes in the heart and most of these changes are exacerbated in the setting of diabetes. A better understanding of how the brain regulates cardiac changes during hypoglycemia will allow for better therapeutic intervention to prevent cardiovascular death associated with hypoglycemia in people with diabetes. The aim of this paper is to provide a narrative review of what is known in the field regarding how the brain regulates the heart during hypoglycemia.

Hypoglycemia and Cardiovascular Disease: Exploring the Connections

It has long been known that administering insulin or insulin secretagogues to treat diabetes has the unfavorable side effect of hypoglycemia. Because hypoglycemia can disrupt normal brain function, it can have a profound impact on people's lives. Studies have shown a connection between hypoglycemia and a higher risk of death and cardiovascular disease. Through experimental studies, numerous potential reasons for the start of cardiovascular events have been discovered. In addition, studies on people have demonstrated that hypoglycemia can result in ventricular arrhythmias. According to recent studies, a number of factors may affect the relationship between hypoglycemia, cardiovascular events, and mortality. Confounding factors may explain the apparent correlation, at least in part. People with comorbidities may experience more hypoglycemia, increasing their risk of mortality. Those who have type 1 or type 2 diabetes, however, seem to be more susceptible to the negative effects of hypoglycemia on the cardiovascular system. When choosing appropriate glucose-lowering treatments and setting glycemic objectives with patients, clinicians should be aware of this risk.

Identification of potential hub genes linked to immune and metabolic alterations in postoperative systemic inflammatory dysregulation

Background

Postoperative systemic inflammatory dysregulation (PSID) is characterised by strongly interlinked immune and metabolic abnormalities. However, the hub genes responsible for the interconnections between these two systemic alterations remain to be identified.

Methods

We analysed differentially expressed genes (DEGs) of individual peripheral blood nucleated cells in patients with PSID (n = 21, CRP > 250 mg/L) and control patients (n = 25, CRP < 75 mg/L) following major abdominal surgery, along with their biological functions. Correlation analyses were conducted to explore the interconnections of immune-related DEGs (irDEGs) and metabolism-related DEGs (mrDEGs). Two methods were used to screen hub genes for irDEGs and mrDEGs: we screened for hub genes among DEGs via 12 algorithms using CytoHubba in Cytoscape, and also screened for hub immune-related and metabolic-related genes using weighted gene co-expression network analysis. The hub genes selected were involved in the interaction between changes in immunity and metabolism in PSID. Finally, we validated our results in mice with PSID to confirm the findings.

Results

We identified 512 upregulated and 254 downregulated DEGs in patients with PSID compared with controls. Gene enrichment analysis revealed that DEGs were significantly associated with immune- and metabolism-related biological processes and pathways. Correlation analyses revealed a close association between irDEGs and mrDEGs. Fourteen unique hub genes were identified via 12 screening algorithms using CytoHubba in Cytoscape and via weighted gene co-expression network analysis. Among these, CD28, CD40LG, MAPK14, and S100A12 were identified as hub genes among both immune- and metabolism-related genes; these genes play a critical role in the interaction between alterations in immunity and metabolism in PSID. The experimental results also showed that the expression of these genes was significantly altered in PSID mice.

Conclusion

This study identified hub genes associated with immune and metabolic alterations in patients with PSID and hub genes that link these alterations. These findings provide novel insights into the mechanisms underlying immune and metabolic interactions and new targets for clinical treatment can be proposed on this basis.

Subclinical Reactive Hypoglycemia with Low Glucose Effectiveness-Why We Cannot Stop Snacking despite Gaining Weight

Obesity has grown worldwide owing to modern obesogenic lifestyles, including frequent snacking. Recently, we studied continuous glucose monitoring in obese/overweight men without diabetes and found that half of them exhibit glucose levels less than 70 mg/dL after a 75-g oral glucose load without notable hypoglycemic symptoms. Interestingly, people with "subclinical reactive hypoglycemia (SRH)" snack more frequently than those without it. Since the ingestion of sugary snacks or drinks could further induce SRH, a vicious cycle of "Snacking begets snacking via SRH" can be formed. Glucose effectiveness (Sg) is an insulin-independent mechanism that contributes to most of the whole-body glucose disposal after an oral glucose load in people without diabetes. Our recent data suggest that both higher and lower Sg are associated with SRH, while the latter but not the former is linked to snacking habits, obesity, and dysglycemia. The present review addresses the possible role of SRH in snacking habits in people with obesity/overweight, taking Sg into account. It is concluded that, for those with low Sg, SRH can be regarded as a link between snacking and obesity. Prevention of SRH by raising Sg might be key to controlling snacking habits and body weight.

Effects of Hypoglycemia on Cardiovascular Function in Patients with Diabetes

Hypoglycemia is common in patients with type 1 and type 2 diabetes (T1D, T2D), treated with insulin or sulfonylureas, and has multiple short- and long-term clinical implications. Whether acute or recurrent, hypoglycemia significantly affects the cardiovascular system with the potential to cause cardiovascular dysfunction. Several pathophysiological mechanisms have been proposed linking hypoglycemia to increased cardiovascular risk, including hemodynamic changes, myocardial ischemia, abnormal cardiac repolarization, cardiac arrhythmias, prothrombotic and proinflammatory effects, and induction of oxidative stress. Hypoglycemia-induced changes can promote the development of endothelial dysfunction, which is an early marker of atherosclerosis. Although data from clinical trials and real-world studies suggest an association between hypoglycemia and cardiovascular events in patients with diabetes, it remains uncertain whether this association is causal. New therapeutic agents for patients with T2D do not cause hypoglycemia and have cardioprotective benefits, whereas increasing the use of new technologies, such as continuous glucose monitoring devices and insulin pumps, has the potential to reduce hypoglycemia and its adverse cardiovascular outcomes in patients with T1D.

Hypoglycaemia in type 1 diabetes mellitus: risks and practical prevention strategies

Hypoglycaemia, which occurs when blood levels of glucose fall below what is considered a normal range, is a well-known complication of insulin therapy in individuals with type 1 diabetes mellitus. Despite advances in diabetes mellitus management, hypoglycaemia has continued to affect the majority of these individuals, leading to suboptimal care and decreased quality of life. Multiple epidemiological studies have demonstrated the risks associated with hypoglycaemic events. With this understanding, various advances have been made in therapeutics for diabetes mellitus management. Diabetes mellitus education continues to form the foundation for management and prevention of hypoglycaemia. The advent of newer diabetes mellitus technologies and newer insulins herald improvements in management strategies and hypoglycaemia prevention. Improved understanding of these newer approaches is needed to ensure delivery of safe and effective care to individuals with type 1 diabetes mellitus, leading to reductions in both the short-term and long-term morbidity and mortality associated with hypoglycaemic events.

Hypoglycaemia aggravates impaired endothelial-dependent vasodilation in diabetes by suppressing endothelial nitric oxide synthase activity and stimulating inducible nitric oxide synthase expression

BACKGROUND

Diabetes exacerbates vascular injury by triggering endothelial dysfunction. Endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) both play major roles in endothelial dysfunction. However, effects of hypoglycaemia, the main complication of the insulin therapy to the glycemic control in diabetes, on eNOS activity and iNOS expression, and underlying mechanisms in diabetes remain unknown. Hence, we aimed to determine the effects of hypoglycaemia on eNOS activity and iNOS expression in different arterial beds of diabetic rats.

METHODS

Sprague-Dawley rats were subjected to Streptozotocin (STZ) combined with high fat diet (HFD) to induce diabetes and then received insulin injection to attain acute and recurrent hypoglycaemia. Immunoblotting was used to analyse the phosphorylation and O-glycosylation status of eNOS and iNOS level from thoracic aorta and mesenteric artery tissue. Indicators of oxidative stress from plasm were determined, and endothelial-dependent vasodilation was detected via wire myograph system.

RESULTS

Hypoglycaemia was associated with a marked increase in eNOS O-GlcNAcylation and decrease in Serine (Ser)-1177 phosphorylation from thoracic aortas and mesenteric arteries. Moreover, hypoglycaemia resulted in elevated phosphorylation of eNOS at Threonine (Thr)-495 site in mesenteric arteries. Besides, changes in these post-translational modifications were associated with increased O-GlcNAc transferase (OGT), decreased phosphorylation of Akt at Ser-473, and increased protein kinase C α subunit (PKCα). iNOS expression was induced in hypoglycaemia. Furthermore, endothelial-dependent vasodilation was impaired under insulin-induced hypoglycaemia, and further in recurrent hypoglycaemia.

CONCLUSIONS

Conclusively, these findings strongly indicate that hypoglycaemia-dependent vascular dysfunction in diabetes is mediated through altered eNOS activity and iNOS expression. Therefore, this implies that therapeutic modulation of eNOS activity and iNOS expression in diabetics under intensive glucose control may prevent and treat adverse cardiovascular events.

The Role of Platelets in Hypoglycemia-Induced Cardiovascular Disease: A Review of the Literature

Cardiovascular diseases (CVDs) are the leading cause of death globally as well as the leading cause of mortality and morbidity in type 2 diabetes (T2D) patients. Results from large interventional studies have suggested hyperglycemia and poor glycemic control to be largely responsible for the development of CVDs. However, the association between hypoglycemia and cardiovascular events is also a key pathophysiological factor in the development of CVDs. Hypoglycemia is especially prevalent in T2D patients treated with oral sulfonylurea agents or exogenous insulin, increasing the susceptibility of this population to cardiovascular events. The adverse cardiovascular risk of hypoglycemia can persist even after the blood glucose levels have been normalized. Hypoglycemia may lead to vascular disease through mechanisms such as enhanced coagulation, oxidative stress, vascular inflammation, endothelial dysfunction, and platelet activation. In the following review, we summarize the evidence for the role of hypoglycemia in platelet activation and the subsequent effects this may have on the development of CVD. In addition, we review current evidence for the effectiveness of therapies in reducing the risk of CVDs.

A review of stress-induced hyperglycaemia in the context of acute ischaemic stroke: Definition, underlying mechanisms, and the status of insulin therapy

The transient elevation of blood glucose produced following acute ischaemic stroke (AIS) has been described as stress-induced hyperglycaemia (SIH). SIH is common even in patients with AIS who have no previous diagnosis of diabetes mellitus. Elevated blood glucose levels during admission and hospitalization are strongly associated with enlarged infarct size and adverse prognosis in AIS patients. However, insulin-intensive glucose control therapy defined by admission blood glucose for SIH has not achieved the desired results, and new treatment ideas are urgently required. First, we explore the various definitions of SIH in the context of AIS and their predictive value in adverse outcomes. Then, we briefly discuss the mechanisms by which SIH arises, describing the dual effects of elevated glucose levels on the central nervous system. Finally, although preclinical studies support lowering blood glucose levels using insulin, the clinical outcomes of intensive glucose control are not promising. We discuss the reasons for this phenomenon.

Pathophysiology and management of hypoglycemia in diabetes

In the century since the discovery of insulin, diabetes has changed from an early death sentence to a manageable chronic disease. This change in longevity and duration of diabetes coupled with significant advances in therapeutic options for patients has fundamentally changed the landscape of diabetes management, particularly in patients with type 1 diabetes mellitus. However, hypoglycemia remains a major barrier to achieving optimal glycemic control. Current understanding of the mechanisms of hypoglycemia has expanded to include not only counter-regulatory hormonal responses but also direct changes in brain glucose, fuel sensing, and utilization, as well as changes in neural networks that modulate behavior, mood, and cognition. Different strategies to prevent and treat hypoglycemia have been developed, including educational strategies, new insulin formulations, delivery devices, novel technologies, and pharmacologic targets. This review article will discuss current literature contributing to our understanding of the myriad of factors that lead to the development of clinically meaningful hypoglycemia and review established and novel therapies for the prevention and treatment of hypoglycemia.

Platelet-Neutrophil Interaction and Thromboinflammation in Diabetes: Considerations for Novel Therapeutic Approaches

Thromboinflammation has become a topic of key interest in cardiovascular disease and the prevention of diabetes complications because of the interplay between thrombosis and inflammation in diabetes. Specifically, the significant risk of vascular thrombotic disease in diabetes highlights the need for new and better therapeutic targets to help manage and prevent vascular thrombo-occlusive disease in this condition. Similarly, the prominent role of inflammation in diabetes has sparked interest in anti-inflammatory agents to better prevent and control vascular disease. Investigations on the effects of anticoagulation and antiplatelet interventions in patients with diabetes and cardiovascular disease show a potential role for these agents in decreasing morbidity and mortality. Neutrophils and platelets are key players in inflammation and wound-healing response, respectively. The interaction between neutrophils and platelets is thought to be an important driver of thromboinflammation. Therefore, this review describes the mechanisms involved in platelet-neutrophil interactions that contribute to the development or exacerbation of thromboinflammation in the context of diabetes and its associated comorbidities. The effects observed by the antithrombotic/antidiabetic treatments and physical activity/dietary interventions on attenuating thromboinflammation are discussed. These data suggest that mechanisms involved in platelet-neutrophil interaction, platelet activation/aggregation, and the recruitment of neutrophils have a promising potential to become therapeutic targets to decrease thromboinflammation in patients with diabetes.

The severity and duration of Hypoglycemia affect platelet-derived protein responses in Caucasians

Objective

Severe hypoglycemia is associated with increased cardiovascular death risk, and platelet responses to hypoglycemia (hypo) have been described. However, the impact of deep transient hypo (deep-hypo) versus prolonged milder hypo (mild-hypo) on platelet response is unclear.

Research Design and methods

Two hypo studies were compared; firstly, mild-hypo in 18-subjects (10 type-2-diabetes (T2D), 8 controls), blood glucose to 2.8mmoL/L (50 mg/dL) for 1-hour; secondly deep-hypo in 46-subjects (23 T2D, 23 controls), blood glucose to < 2.2mmoL/L (< 40 mg/dL) transiently. Platelet-related protein (PRP) responses from baseline to after 1-hour of hypo (mild-hypo) or at deep-hypo were compared, and at 24-hours post-hypo. Slow Off-rate Modified Aptamer (SOMA)-scan plasma protein measurement was used to determine PRP changes for 13 PRPs.

Results

In controls, from baseline to hypo, differences were seen for four PRPs, three showing increased %change in deep-hypo (Plasminogen activator inhibitor-1(PAI-1), CD40 ligand (CD40LG) and Protein-S), one showing increased %change in mild-hypo (von Willebrand factor (vWF)); at 24-hours in controls, %change for Protein-S remained increased in deep-hypo, whilst % change for vWF and plasminogen were increased in mild-hypo. In T2D, from baseline to hypo, differences were seen for 4 PRPs, three showing increased %change in deep-hypo (PAI-1, platelet glycoprotein VI and Tissue factor), one showing increased %change in mild-hypo (CD40LG); at 24-hours in T2D, %change for CD40LG remained increased, together with vWF, in deep-hypo.

Conclusion

Both mild-hypo and deep-hypo showed marked PRP changes that continued up to 24-hours, showing that both the severity and duration of hypoglycemia are likely important and that any degree of hypoglycemia may be detrimental for increased cardiovascular risk events through PRP changes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01639-w.

Association of Hypoglycemia with Biomarkers of Oxidative Stress and Antioxidants: An Observational Study

Hypoglycemia has been associated with complications from the vasculature. The contributing effects of oxidative stress (OS) on these actions have not been sufficiently studied, especially in daily, routine clinical practice. We examined the association of hypoglycemia encountered in daily clinical practice with biomarkers of OS and endogenous antioxidant activity in persons with diabetes [type 1 (T1D) or type 2 (T2D)], as well as individuals without diabetes, with a history of hypoglycemia. Several biomarkers of OS (MDA, ADMA, ox-LDL, 3-NT, protein carbonyls, 4-HNE, TBARS) and antioxidant capacity (TAC, superoxide scavenging capacity, hydroxyl radical scavenging capacity, reducing power, ABTS) were measured. Blood was drawn at the time of hypoglycemia detection and under euglycemic conditions on a different day. A total of 31 participants (mean age [±SD] 52.2 ± 21.1 years, 45.2% males) were included in the study. There were 14 (45.2%) persons with T2D, 12 (38.7%) with T1D, and 5 (16.1%) without diabetes. We found no differences in the examined biomarkers. Only TBARS, a biomarker of lipid peroxidation, showed lower values during hypoglycemia (p = 0.005). This finding needs confirmation in more extensive studies, given that MDA, another biomarker of lipid peroxidation, was not affected. Our study suggests that hypoglycemia encountered in daily clinical practice does not affect OS.

Stress, hypoglycemia, and the autonomic nervous system

Stress can be classified as either psychosocial or physiologic. Physiologic stress refers to stresses due to acute illness, trauma, pain, hypoglycemia, and sleep deprivation-much less is known regarding its health consequences. This review focuses on hypoglycemia as a model to further investigate physiological stress. Experimental mild to moderate hypoglycemia is a paradigmatic physiological stress that evokes autonomic, neuroendocrine, and immune responses. Hypoglycemic stress is an ideal model to examine the interactions and consequences of physiological stress on the autonomic nervous system. Acute hypoglycemia has been demonstrated to increase inflammatory markers, prolong QTc, and impair cardiac-vagal baroreflex sensitivity. Some of these consequences may not reverse completely when euglycemia is restored. For example, there is attenuation of the cardiac-vagal baroreflex, attenuation of the vascular sympathetic baroreflex (muscle sympathetic nerve activity response to transient hypotension), and attenuation of the catecholamine response to lower body negative pressure that is present the next day after hypoglycemia has resolved.

Admission Blood Glucose Level and Its Association With Cardiovascular and Renal Complications in Patients Hospitalized With COVID-19

OBJECTIVE

To investigate the association between admission blood glucose levels and risk of in-hospital cardiovascular and renal complications.

RESEARCH DESIGN AND METHODS

In this multicenter prospective study of 36,269 adults hospitalized with COVID-19 between 6 February 2020 and 16 March 2021 (N = 143,266), logistic regression models were used to explore associations between admission glucose level (mmol/L and mg/dL) and odds of in-hospital complications, including heart failure, arrhythmia, cardiac ischemia, cardiac arrest, coagulation complications, stroke, and renal injury. Nonlinearity was investigated using restricted cubic splines. Interaction models explored whether associations between glucose levels and complications were modified by clinically relevant factors.

RESULTS

Cardiovascular and renal complications occurred in 10,421 (28.7%) patients; median admission glucose level was 6.7 mmol/L (interquartile range 5.8-8.7) (120.6 mg/dL [104.4-156.6]). While accounting for confounders, for all complications except cardiac ischemia and stroke, there was a nonlinear association between glucose and cardiovascular and renal complications. For example, odds of heart failure, arrhythmia, coagulation complications, and renal injury decreased to a nadir at 6.4 mmol/L (115 mg/dL), 4.9 mmol/L (88.2 mg/dL), 4.7 mmol/L (84.6 mg/dL), and 5.8 mmol/L (104.4 mg/dL), respectively, and increased thereafter until 26.0 mmol/L (468 mg/dL), 50.0 mmol/L (900 mg/dL), 8.5 mmol/L (153 mg/dL), and 32.4 mmol/L (583.2 mg/dL). Compared with 5 mmol/L (90 mg/dL), odds ratios at these glucose levels were 1.28 (95% CI 0.96, 1.69) for heart failure, 2.23 (1.03, 4.81) for arrhythmia, 1.59 (1.36, 1.86) for coagulation complications, and 2.42 (2.01, 2.92) for renal injury. For most complications, a modifying effect of age was observed, with higher odds of complications at higher glucose levels for patients age <69 years. Preexisting diabetes status had a similar modifying effect on odds of complications, but evidence was strongest for renal injury, cardiac ischemia, and any cardiovascular/renal complication.

CONCLUSIONS

Increased odds of cardiovascular or renal complications were observed for admission glucose levels indicative of both hypo- and hyperglycemia. Admission glucose could be used as a marker for risk stratification of high-risk patients. Further research should evaluate interventions to optimize admission glucose on improving COVID-19 outcomes.

Severe Hypoglycemia Increases Dementia Risk and Related Mortality: A Nationwide, Population-based Cohort Study

CONTEXT

There are few studies focused on the relationship between hypoglycemia and new-onset dementia in patients with type 2 diabetes and no study regarding mortality of dementia after hypoglycemia.

OBJECTIVE

We investigated the effect of severe hypoglycemia on dementia subtypes and its relation to overall mortality in patients with type 2 diabetes.

METHODS

We evaluated incident dementia, including Alzheimer disease and vascular dementia, among health checkup participants aged 40 years or older in the National Health Insurance System in Korea from January 2009 to December 2015. Episodes of severe hypoglycemia were examined for 3 years before the date of the health checkup.

RESULTS

Among 2 032 689 participants (1 172 271 men, 860 418 women), 14 443 (0.7%) experienced severe hypoglycemia, during a mean follow-up period of 6.9 ± 1.7 years. Individuals in the severe hypoglycemia group were more likely to be diagnosed with dementia compared to individuals without severe hypoglycemia (23.3% vs 7.3%; P < .001) and the overall incidence of Alzheimer disease was higher than vascular dementia. Dementia risk rose with increasing number of severe hypoglycemic episodes (1 episode [hazard ratio (HR) = 1.54; 95% CI, 1.48-1.60], 2 or more episodes [HR = 1.80; 95% CI, 1.66-1.94]). Overall mortality was higher in participants with dementia, but without severe hypoglycemia (HR = 2.03; 95% CI, 1.96-2.10) and severe hypoglycemia, but without dementia (HR = 4.24; 95% CI, 4.29-4.40), and risk of death was highest in those with both severe hypoglycemia and dementia (HR = 5.08; 95% CI, 4.83-5.35).

CONCLUSION

Severe hypoglycemia is associated with dementia, especially Alzheimer disease and mortality; together, they have an additive effect on overall mortality.

Significance of Glycemic Variability in Diabetes Mellitus

The goal of diabetes treatment is to maintain good glycemic control, prevent the development and progression of diabetic complications, and ensure the same quality of life and life expectancy as healthy people. Hemoglobin A1c (HbA1c) is used as an index of glycemic control, but strict glycemic control using HbA1c as an index may lead to severe hypoglycemia and cardiovascular death. Glycemic variability (GV), such as excessive hyperglycemia and hypoglycemia, is associated with diabetic vascular complications and has been recognized as an important index of glycemic control. Here, we reviewed the definition and evaluated the clinical usefulness of GV, and its relationship with diabetic complications and therapeutic strategies to reduce GV.

Hyperglycemia in acute ischemic stroke: physiopathological and therapeutic complexity

Diabetes mellitus and associated chronic hyperglycemia enhance the risk of acute ischemic stroke and lead to worsened clinical outcome and increased mortality. However, post-stroke hyperglycemia is also present in a number of non-diabetic patients after acute ischemic stroke, presumably as a stress response. The aim of this review is to summarize the main effects of hyperglycemia when associated to ischemic injury in acute stroke patients, highlighting the clinical and neurological outcomes in these conditions and after the administration of the currently approved pharmacological treatment, i.e. insulin. The disappointing results of the clinical trials on insulin (including the hypoglycemic events) demand a change of strategy based on more focused therapies. Starting from the comprehensive evaluation of the physiopathological alterations occurring in the ischemic brain during hyperglycemic conditions, the effects of various classes of glucose-lowering drugs are reviewed, such as glucose-like peptide-1 receptor agonists, DPP-4 inhibitors and sodium glucose cotransporter 2 inhibitors, in the perspective of overcoming the up-to-date limitations and of evaluating the effectiveness of new potential therapeutic strategies.

Hypoglycemia-induced changes in complement pathways in type 2 diabetes

Background and aims

An association between hypoglycaemia and adverse cardiovascular events has been suggested from longitudinal and retrospective cohort studies. The complement pathway proteins in hypoglycemia are not well studied. Here, we hypothesized that these circulating proteins would be elevated in response to hypoglycemia in type 2 diabetes (T2D) through the inflammatory response.

Methods

A prospective, parallel study in T2D (n = 23) and controls (n = 23). Subjects underwent insulin-induced hypoglycemia with blood sampling at baseline, hypoglycemia and post-hypoglycemia; SOMAscan proteomic analysis of complement pathway-related proteins, cytokines and inflammatory proteins was undertaken.

Results

At baseline: Complement C2 (p < 0.05) and Factor B (p < 0.05) were elevated in T2D. At hypoglycemia: Complement C2 (p < 0.05) and Factor B (p < 0.01) remained elevated, whilst Factor I became elevated (p < 0.05) in T2D; Complement C4b became elevated in controls (p < 0.05). In the post-hypoglycemia follow up period, Complement C2, Factor B and Factor I remained elevated in T2D; in addition, Factor D, Factor H and mannose-binding protein C showed elevations in T2D, whilst properdin, complement C3b, Factor H-related protein 5, complement C1q and decay-accelerating factor (DAF) showed elevations in controls. Granger causality analysis showed that inflammatory proteins appeared to drive complement protein changes in T2D; conversely, in controls, complement proteins drove inflammatory protein changes.

Conclusions

Baseline elevations in C2 and Factor B indicate upregulation of the complement pathway in T2D. Changes in complement pathway-related protein levels in response to hypoglycemia suggest both intrinsic and alternative pathway activation at 2-h that appears driven by the underlying inflammation in T2D and could contribute to a cardiovascular event.ClinicalTrials.gov NCT03102801. Date of registration April 6, 2017, retrospectively registered. https://clinicaltrials.gov/ct2/show/NCT03102801?term=NCT03102801&draw=2&rank=1.

Hepatocyte-specific glucose-6-phosphatase deficiency disturbs platelet aggregation and decreases blood monocytes upon fasting-induced hypoglycemia

OBJECTIVE

Glycogen storage disease type 1a (GSD Ia) is a rare inherited metabolic disorder caused by mutations in the glucose-6-phosphatase (G6PC1) gene. When untreated, GSD Ia leads to severe fasting-induced hypoglycemia. Although current intensive dietary management aims to prevent hypoglycemia, patients still experience hypoglycemic events. Poor glycemic control in GSD Ia is associated with hypertriglyceridemia, hepatocellular adenoma and carcinoma, and also with an increased bleeding tendency of unknown origin.

METHODS

To evaluate the effect of glycemic control on leukocyte levels and coagulation in GSD Ia, we employed hepatocyte-specific G6pc1 deficient (L-G6pc-/-) mice under fed or fasted conditions, to match good or poor glycemic control in GSD Ia, respectively.

RESULTS

We found that fasting-induced hypoglycemia in L-G6pc-/- mice decreased blood leukocytes, specifically proinflammatory Ly6Chi monocytes, compared to controls. Refeeding reversed this decrease. The decrease in Ly6Chi monocytes was accompanied by an increase in plasma corticosterone levels and was prevented by the glucocorticoid receptor antagonist mifepristone. Further, fasting-induced hypoglycemia in L-G6pc-/- mice prolonged bleeding time in the tail vein bleeding assay, with reversal by refeeding. This could not be explained by changes in coagulation factors V, VII, or VIII, or von Willebrand factor. While the prothrombin and activated partial thromboplastin time as well as total platelet counts were not affected by fasting-induced hypoglycemia in L-G6pc-/- mice, ADP-induced platelet aggregation was disturbed.

CONCLUSIONS

These studies reveal a relationship between fasting-induced hypoglycemia, decreased blood monocytes, and disturbed platelet aggregation in L-G6pc-/- mice. While disturbed platelet aggregation likely accounts for the bleeding phenotype in GSD Ia, elevated plasma corticosterone decreases the levels of proinflammatory monocytes. These studies highlight the necessity of maintaining good glycemic control in GSD Ia.

Higher long-term visit-to-visit glycemic variability predicts new-onset atrial fibrillation in patients with diabetes mellitus

Background

Atrial fibrillation (AF) is prevalent in patients with type 2 diabetes mellitus (T2DM). Glycemic variability (GV) is associated with risk of micro- and macrovascular diseases. However, whether the GV can increase the risk of AF remains unknown.

Methods

The cohort study used a database from National Taiwan University Hospital, a tertiary medical center in Taiwan. Between 2014 and 2019, a total of 27,246 adult patients with T2DM were enrolled for analysis. Each individual was assessed to determine the coefficients of variability of fasting glucose (FGCV) and HbA1c variability score (HVS). The GV parameters were categorized into quartiles. Multivariate Cox regression models were employed to estimate the relationship between the GV parameters and the risk of AF, transient ischemic accident (TIA)/ischemic stroke and mortality in patients with T2DM.

Results

The incidence rates of AF and TIA/ischemic stroke were 21.31 and 13.71 per 1000 person-year respectively. The medium follow-up period was 70.7 months. In Cox regression model with full adjustment, the highest quartile of FGCV was not associated with increased risk of AF [Hazard ratio (HR): 1.12, 95% confidence interval (CI) 0.96–1.29, p = 0.148] or TIA/ischemic stroke (HR: 1.04, 95% CI 0.83–1.31, p = 0.736), but was associated with increased risk of total mortality (HR: 1.33, 95% CI 1.12–1.58, p < 0.001) and non-cardiac mortality (HR: 1.41, 95% CI 1.15–1.71, p < 0.001). The highest HVS was significantly associated with increased risk of AF (HR: 1.29, 95% CI 1.12–1.50, p < 0.001), total mortality (HR: 2.43, 95% CI 2.03–2.90, p < 0.001), cardiac mortality (HR: 1.50, 95% CI 1.06–2.14, p = 0.024) and non-cardiac mortality (HR: 2.80, 95% CI 2.28–3.44, p < 0.001) but was not associated with TIA/ischemic stroke (HR: 0.98, 95% CI 0.78–1.23, p = 0.846). The Kaplan–Meier analysis showed significantly higher risk of AF, cardiac and non-cardiac mortality according to the magnitude of GV (log-rank test, p < 0.001).

Conclusions

Our data demonstrate that high GV is independently associated with the development of new-onset AF in patients with T2DM. The benefit of maintaining stable glycemic levels to improve clinical outcomes warrants further studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01341-3.

GLP-1 Receptor: A New Target for Sepsis

Patients with sepsis often exhibit hyperglycemia, which increases mortality. glucagon-like peptide-1 receptor agonists (GLP-1RAs) not only regulate blood glucose homeostasis but also improve organ dysfunction, regulate immunity, and control inflammation and other functions in patients with sepsis. Here, we review the possible application of GLP-1RAs in sepsis, to provide a new perspective for the clinical diagnosis and treatment of patients with sepsis complicated with stress hyperglycemia.

Effect of hypoglycaemia on measures of myocardial blood flow and myocardial injury in adults with and without type 1 diabetes: A prospective, randomised, open-label, blinded endpoint, cross-over study

AIMS

This study examined the effect of experimentally-induced hypoglycaemia on measures of myocardial blood flow and myocardial injury in adults with, and without, type 1 diabetes.

METHODS

In a prospective, randomised, open-label, blinded, endpoint cross-over study, 17 young adults with type 1 diabetes with no cardiovascular risk factors, and 10 healthy non-diabetic volunteers, underwent hyperinsulinaemic-euglycaemic (blood glucose 4.5-5.5 mmol/L) and hypoglycaemic (2.2-2.5 mmol/L) clamps. Myocardial blood flow was assessed using transthoracic echocardiography Doppler coronary flow reserve (CFR) and myocardial injury using plasma high-sensitivity cardiac troponin I (hs-cTnI) concentration.

RESULTS

During hypoglycaemia, coronary flow reserve trended non-significantly lower in those with type 1 diabetes than in the non-diabetic participants (3.54 ± 0.47 vs. 3.89 ± 0.89). A generalised linear mixed-model analysis examined diabetes status and euglycaemia or hypoglycaemia as factors affecting CFR. No statistically significant difference in CFR was observed for diabetes status (p = .23) or between euglycaemia and hypoglycaemia (p = .31). No changes in hs-cTnI occurred during hypoglycaemia or in the recovery period (p = .86).

CONCLUSIONS

A small change in CFR was not statistically significant in this study, implying hypoglycaemia may require more than coronary vasomotor dysfunction to cause harm. Further larger studies are required to investigate this putative problem.

The Association Between Second-Line Oral Antihyperglycemic Medication on Types of Dementia in Type 2 Diabetes: A Nationwide Real-World Longitudinal Study

BACKGROUND

There are few reports that evaluated the association between various types of dementia and dual oral therapy with antihyperglycemic medication.

OBJECTIVE

The goal of this study was to investigate the association between treatment of dual antihyperglycemic medication and dementia subclass in type 2 diabetes mellitus using the Korean National Health Insurance System.

METHODS

This study included 701,193 individuals with diabetes prescribed dual oral therapy between 2009 and 2012 from the Korean National Health Insurance Service Database, which were tracked until 2017. All-cause, Alzheimer's (AD) and vascular dementia (VaD) were investigated by dual oral therapy. Adjustments were made for age, sex, income, diabetes duration, hypertension, dyslipidemia, smoking, drinking, exercise, body mass index, glucose level, and estimated glomerular filtration rate.

RESULTS

Dual therapy with metformin (Met) + dipeptidyl peptidase-4 inhibitor (DPP-4i), Met + thiazolidinedione (TZD), and sulfonylurea (SU) + thiazolidinediones (TZD) were significantly associated with all-cause dementia (HR = 0.904, 0.804, and 0.962, respectively) and VaD (HR = 0.865, 0.725, and 0.911, respectively), compared with Met + SU. Met + DPP-4i and Met + TZD were associated with significantly lower risk of AD (HR = 0.922 and 0.812), compared with Met + SU. Dual therapy with TZD was associated with a significantly lower risk of all-cause dementia, AD, and VaD than nonusers of TZD (HR = 0.918, 0.925 and 0.859, respectively).

CONCLUSION

Adding TZD or DPP-4i instead of SU as second-line anti-diabetic treatment may be considered for delaying or preventing dementia. Also, TZD users relative to TZD non-users on dual oral therapy were significantly associated with lower risk of various types of dementia.

History of Severe Hypoglycemia in Type 2 Diabetes Mellitus Unmasked Significant Atherosclerotic Coronary Artery Disease: A Comparative Case Control Study

Objectives

A history of severe hypoglycemia (SH) is associated with cardiovascular (CV) events among patients with type 2 diabetes mellitus (T2DM). In this study, we compared the severity of atherosclerotic coronary artery disease (ACAD) in T2DM patients with and without a history of SH.

Methodology

We conducted a comparative case-control study involving 28 T2DM patients with a history of SH within the last 5 years with no documented ACAD, and matched them with 28 T2DM patients with no history of SH. All subjects underwent coronary artery calcium scoring (CACS) with or without coronary computed tomographic angiography (CCTA) to evaluate the severity of ACAD.

Results

A history of SH in T2DM was associated with a higher prevalence of significant ACAD (79% versus 46%, p=0.026). A high CACS (≥100) was seen in a greater number of patients with a history of SH compared to those without (75% versus 43%, p=0.029). Similarly, there was a higher prevalence of obstructive CAD in those with a history of SH compared to those without (72% versus 39%, p=0.036). Median C-reactive protein level was also higher among patients with a history of SH (0.41 mg/dL versus 0.16 mg/dL, p=0.029).

Conclusion

In patients with T2DM, a history of SH is significantly associated with ACAD compared to those without SH. A history of SH warrants screening for ACAD.

Hypoglycaemia and Cardiovascular Disease Risk in Patients with Diabetes

Hypoglycaemia represents an important side effect of insulin therapy and insulin secretagogues. It can occur in both type 1 and type 2 diabetes mellitus patients. Also, some associations between hypoglycaemia and cardiovascular (CV) risk have been reported. Several mechanisms may be involved, including the sympathoadrenal system, hypokalaemia, endothelial dysfunction, coagulation, platelets, inflammation, atherothrombosis and impaired autonomic cardiac reflexes. This narrative review discusses the associations of hypoglycaemia with CV diseases, including coronary heart disease (CHD), cardiac arrhythmias, stroke, carotid disease and peripheral artery disease (PAD), as well as with dementia. Severe hypoglycaemia has been related to CHD, CV and all-cause mortality. Furthermore, there is evidence supporting an association between hypoglycaemia and cardiac arrhythmias, potentially predisposing to sudden death. The data linking hypoglycaemia with stroke, carotid disease and PAD is limited. Several factors may affect the hypoglycaemia-CV relationships, such as the definition of hypoglycaemia, patient characteristics, co-morbidities (including chronic kidney disease) and antidiabetic drug therapy. However, the association between hypoglycaemia and dementia is bilateral. Both the disorders are more common in the elderly; thus, glycaemic goals should be carefully selected in older patients. Further research is needed to elucidate the impact of hypoglycaemia on CV disease.

Severe hypoglycemia as a preventable risk factor for cardiovascular disease in patients with type 2 diabetes mellitus

Glucose-lowering medication and lifestyle modification are essential for optimal glycemic control in patients with type 2 diabetes mellitus (T2DM). However, glucose-lowering agents, particularly insulin and insulin secretagogues, may cause hypoglycemia, which has multiple negative effects on the cardiovascular (CV) system and may cause death. Previous studies using institutional data from the Korean Nationwide Health Insurance database have consistently found a causal relationship between severe hypoglycemia and CV outcomes and mortality. Screening for high-risk patients, appropriate management, and intensive individualized education are the most effective measures and essential for the prevention of harmful hypoglycemic events. Based on identified risk factors that predict severe hypoglycemia, we developed an 1-year risk prediction model for severe hypoglycemia that can be used in clinical settings. In this review, we describe the current understanding of severe hypoglycemia and the clinical implications in patients with T2DM. Furthermore, we highlight the importance of intensive individualized education for high-risk patients and the risk prediction model to reduce severe hypoglycemia.

Associations between continuous glucose monitoring-derived metrics and arterial stiffness in Japanese patients with type 2 diabetes

BACKGROUND

Previous studies have suggested that high mean glucose levels and glycemic abnormalities such as glucose fluctuation and hypoglycemia accelerate the progression of atherosclerosis in patients with type 2 diabetes. Although continuous glucose monitoring (CGM) that could evaluate such glycemic abnormalities has been rapidly adopted, the associations between CGM-derived metrics and arterial stiffness are not entirely clear.

METHODS

This exploratory cross-sectional study used baseline data from an ongoing prospective, multicenter, observational study with 5 years of follow-up. Study participants included 445 outpatients with type 2 diabetes and no history of apparent cardiovascular disease who underwent CGM and brachial-ankle pulse wave velocity (baPWV) measurement at baseline. Associations between CGM-derived metrics and baPWV were analyzed using multivariate regression models.

RESULTS

In a linear regression model, all CGM-derived metrics were significantly associated with baPWV, but HbA1c was not. Some CGM-derived metrics related to intra-day glucose variability, hyperglycemia, and hypoglycemia remained significantly associated with baPWV after adjusting for possible atherosclerotic risk factors, including HbA1c. Based on baPWV ≥ 1800 cm/s as indicative of high arterial stiffness, multivariate logistic regression found that some CGM-derived metrics related to intra-day glucose variability and hyperglycemia are significantly associated with high arterial stiffness even after adjusting for possible atherosclerotic risk factors, including HbA1c.

CONCLUSIONS

Multiple CGM-derived metrics are significantly associated with baPWV and high arterial stiffness in patients with type 2 diabetes who have no history of apparent cardiovascular disease. These metrics might be useful for identifying patients at high risk of developing cardiovascular disease.

Hypoglycemia increases endothelial-dependent vasodilation through suppressing phosphorylation at Threonine 495/497 site of endothelial nitric oxide synthase

OBJECTIVE

Phosphorylation plays an essential role in the regulation of endothelial nitric oxide synthase (eNOS) activity. However, the phosphorylation of eNOS under hypoglycemia and whether hypoglycemia changes eNOS activity is unknown. This paper aims to clarify the regulation of eNOS phosphorylation and its activity change under hypoglycemia.

METHODS

Bovine aortic endothelial cells (BAECs) and Sprague-Dawley rats were treated with hypoglycemia, and the phosphorylation of eNOS was subjected to western blot. Blood nitric oxide (NO) concentration was determined by NO kit and endothelial-dependent vasodilation was detected by multi-wire myograph.

RESULTS

In both BAECs and rats' thoracic aorta, hypoglycemia induced eNOS phosphorylation decrease specifically on Threonine (Thr) 497. Inhibition of ubiquitination of protein kinase C α subunit (PKCα) reverses the decrease of eNOS phosphorylation in hypoglycemia. Ubiquitinated PKCα can be reversed by AMPK knockdown. In rats, insulin induced hypoglycemia increased the concentration of NO in arterial blood, and progressively enhanced the endothelium-dependent vasodilation of the thoracic and mesenteric aorta.

CONCLUSIONS

In vitro, the activation of AMPK may lead to the expression of PKCα by regulating ubiquitination, resulting in a decrease in the level of P-eNOS Thr497 phosphorylation under hypoglycemia. In vivo, insulin-induced hypoglycemia produces a beneficial cardiovascular effect on rats.

Effects of DPP-4 Inhibitors on Blood Glucose Variability in Japanese Patients with Type 2 Diabetes on Maintenance Hemodialysis: A Prospective Observational Exploratory Study

INTRODUCTION

The precise blood glucose (BG) profile of hemodialysis patients is unclear, as is the effectiveness of dipeptidyl peptidase-4 (DPP-4) inhibitors in hemodialysis patients with type 2 diabetes. Here, we used continuous glucose monitoring (CGM) to evaluate BG variability in these patients and to assess the efficacy of DPP-4 inhibitors, particularly during hemodialysis sessions and at nighttime (UMIN000012638).

METHODS

We examined BG profiles using CGM in 31 maintenance hemodialysis patients with type 2 diabetes. Differences between patients with and without DPP-4 inhibitors (n = 15 and 16, respectively) were analyzed using a linear mixed-effects model to assess changes in glucose levels in 5-min intervals.

RESULTS

The model revealed that DPP-4 inhibitor use was significantly associated with suppression of a rapid drop in glucose levels, both with and without adjustment for BG levels at the start of hemodialysis. Moreover, the model revealed that the two groups differed significantly in the pattern of changes in BG levels from 0:00 to 6:55 am. DPP-4 inhibitors suppressed the tendency for subsequent nocturnal hypoglycemia.

CONCLUSIONS

This prospective observational exploratory study showed that DPP-4 inhibitors could suppress BG variability during hemodialysis sessions as well as subsequent nocturnal changes in patients with type 2 diabetes.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, UMIN000012638.

Risk of severe hypoglycaemia and its impact in type 2 diabetes in DEVOTE

AIMS

To undertake a post-hoc analysis, utilizing a hypoglycaemia risk score based on DEVOTE trial data, to investigate if a high risk of severe hypoglycaemia was associated with an increased risk of cardiovascular events, and whether reduced rates of severe hypoglycaemia in patients identified as having the highest risk affected the risk of cardiovascular outcomes.

MATERIALS AND METHODS

The DEVOTE population was divided into quartiles according to patients' individual hypoglycaemia risk scores. For each quartile, the observed incidence and rate of severe hypoglycaemia, major adverse cardiovascular event (MACE) and all-cause mortality were determined to investigate whether those with the highest risk of hypoglycaemia were also at the greatest risk of MACE and all-cause mortality. In addition, treatment differences within each risk quartile [insulin degludec (degludec) vs. insulin glargine 100 units/mL (glargine U100)] in terms of severe hypoglycaemia, MACE and all-cause mortality were investigated.

RESULTS

Patients with the highest risk scores had the highest rates of severe hypoglycaemia, MACE and all-cause mortality. Treatment ratios between degludec and glargine U100 in the highest risk quartile were 95% confidence interval (CI) 0.56 (0.39; 0.80) (severe hypoglycaemia), 95% CI 0.76 (0.58; 0.99) (MACE) and 95% CI 0.77 (0.55; 1.07) (all-cause mortality).

CONCLUSIONS

The risk score demonstrated that a high risk of severe hypoglycaemia was associated with a high incidence of MACE and all-cause mortality and that, in this high-risk group, those treated with degludec had a lower incidence of MACE. These observations support the hypothesis that hypoglycaemia is a risk factor for cardiovascular events.

Interleukin-6 response to insulin-induced hypoglycemia is associated with hypothalamic-pituitary-adrenal axis activation

Increased plasma levels of interleukin-6 (IL-6) in response to acute hypoglycemia have been well documented. Aiming to study the interaction between IL-6 and counter-regulatory hormones during hypoglycemic stress we conducted an exploratory single center study involving 26 adult patients undergoing insulin tolerance test. Insulin-induced hypoglycemia elicited a significant dynamic response of IL-6, adrenaline, noradrenaline, GH, prolactin, ACTH and serum and salivary cortisol (P < 0.001 for all variables). Patients with insufficient HPA axis response had lower hypoglycemia-induced IL-6 increase (median: 0.88 pg/mL) compared with individuals with intact HPA axis response (2.03 pg/mL, P = 0.007). IL-6 maximal increase correlated with the maximal increase of serum cortisol (rs = 0.48; P = 0.013), salivary cortisol (rs = 0.66; P = 0.012), plasma ACTH (rs = 0.48; P = 0.013) and with the increase in procedure-related symptoms of anxiety and hypoglycemia (rs = 0.57; P = 0.003). In conclusion, hypoglycemic stress-induced IL-6 increase is associated with activation of the HPA axis, suggesting that IL-6 response to hypoglycemic stress may be regarded as part of the counter-regulatory response, possibly contributing to the maintenance of glucose homeostasis.

Effect of mean HbA1c on the association of HbA1c variability and all-cause mortality in patients with type 2 diabetes

AIM

To evaluate the effect of mean HbA1c on the correlation between HbA1c variability and all-cause mortality, and the risks associated with different levels of HbA1c and glycaemic control status in patients with type 2 diabetes.

MATERIALS AND METHODS

Patients with type 2 diabetes and at least three HbA1c measurements within 12-24 months were included. HbA1c variability score, coefficient of variation (CV) and standard deviation (SD) were used to evaluate variability. A variability score of 50 was set as a cutoff to define low and high variability.

RESULTS

A total of 4216 patients were included, of whom 1196 died during the observation period (11.1 ± 3.2 years). All-cause mortality increased with HbA1c variability score and the quartiles of HbA1c CV and SD. The strength of this association was attenuated after adjustment for mean HbA1c, and the risks associated with HbA1c variability and glycaemic control status were similar. The highest associated risk was observed with an HbA1c variability score of >50 and mean HbA1c of ≥7.5%. Mortality risk was significantly higher with a mean HbA1c of ≤6.0% and >8.5% and of ≤6.0% and >8.0% for low and high HbA1c variability, respectively.

CONCLUSIONS

Mean HbA1c contributed to the correlation between HbA1c variability and all-cause mortality. The risks associated with HbA1c variability and glycaemic control status were similar. The relationship between mean HbA1c and mortality presented a J-shaped distribution for both low and high HbA1c variability.

Effect of induced hypoglycemia on inflammation and oxidative stress in type 2 diabetes and control subjects

Intensive diabetes control has been associated with increased mortality in type 2 diabetes (T2DM); this has been suggested to be due to increased hypoglycemia. We measured hypoglycemia-induced changes in endothelial parameters, oxidative stress markers and inflammation at baseline and after a 24-hour period in type 2 diabetic (T2DM) subjects versus age-matched controls. Case-control study: 10 T2DM and 8 control subjects. Blood glucose was reduced from 5 (90 mg/dl) to hypoglycemic levels of 2.8 mmol/L (50 mg/dl) for 1 hour by incremental hyperinsulinemic clamps using baseline and 24 hour samples. Measures of endothelial parameters, oxidative stress and inflammation at baseline and at 24-hours post hypoglycemia were performed: proteomic (Somalogic) analysis for inflammatory markers complemented by C-reactive protein (hsCRP) measurement, and proteomic markers and urinary isoprostanes for oxidative measures, together with endothelial function. Between baseline and 24 -hours after hypoglycemia, 15 of 140 inflammatory proteins differed in T2DM whilst only 1 of 140 differed in controls; all returned to baseline at 24-hours. However, elevated hsCRP levels were seen at 24-hours in T2DM (2.4 mg/L (1.2-5.4) vs. 3.9 mg/L (1.8-6.1), Baseline vs 24-hours, P < 0.05). In patients with T2DM, between baseline and 24-hour after hypoglycemia, only one of 15 oxidative stress proteins differed and this was not seen in controls. An increase (P = 0.016) from baseline (73.4 ng/mL) to 24 hours after hypoglycemia (91.7 ng/mL) was seen for urinary isoprostanes. Hypoglycemia resulted in inflammatory and oxidative stress markers being elevated in T2DM subjects but not controls 24-hours after the event.

Severe hypoglycemia exacerbates myocardial dysfunction and metabolic remodeling in diabetic mice

Although several studies have revealed that adverse cardiovascular events in diabetic patients are closely associated with severe hypoglycemia (SH), the causal relationship and related mechanisms remain unclear. This study aims to investigate whether SH promotes myocardial injury and further explores the potential mechanisms with focus on disturbances in lipid metabolism. SH promoted myocardial dysfunction and structural disorders in the diabetic mice but not in the controls. SH also enhanced the production of myocardial proinflammatory cytokines and oxidative stress. Moreover, myocardial lipid deposition developed in diabetic mice after SH, which was closely related to myocardial dysfunction and the inflammatory response. We further found that myocardial metabolic remodeling was associated with changes in PPAR-β/δ and its target molecules in diabetic mice exposed to SH. These findings demonstrate that SH exacerbates myocardial dysfunction and the inflammatory response in diabetic mice, which may be induced by myocardial metabolic remodeling via PPAR-β/δ.

Hypoglycaemia leads to a delayed increase in platelet and coagulation activation markers in people with type 2 diabetes treated with metformin only: Results from a stepwise hypoglycaemic clamp study

AIMS

To investigate the effect of hypoglycaemia on platelet and coagulation activation in people with type 2 diabetes.

MATERIALS AND METHODS

This monocentric, open, single-arm, mechanistic trial included 14 people with established type 2 diabetes (four women, 10 men, age 55 ± 7 years, glycated haemoglobin concentration 51 ± 7 mmol/mol) receiving metformin monotherapy. A stepwise hyperinsulinaemic-hypoglycaemic clamp experiment (3.5 and 2.5 mmol/L, for 30 minutes respectively) was performed, aiming to investigate platelet and coagulation activity during predefined plateaus of hypoglycaemia, as well as 1 day and 7 days later.

RESULTS

While platelet activation assessed by light transmittance aggregometry did not significantly increase after the hypoglycaemic clamp procedure, the more sensitive flow cytometry-based measurement of platelet surface activation markers showed hypoglycaemia-induced activation 24 hours (PAC1^pos CD62P^pos , PAC1^pos CD63P^pos and PAC1^pos CD62P^pos CD63^pos ; P < .01) and 7 days after the hypoglycaemic clamp (P < .001 for PAC1^pos CD63^pos ; P < .01 for PAC1^pos CD62P^pos and PAC1^pos CD62P^pos CD63^pos ) in comparison to baseline. Coagulation markers, such as fibrinogen, D-dimer, plasminogen activator inhibitor-1, von Willebrand factor activity and factor VIII, were also significantly increased, an effect that was most pronounced 24 hours after the hypoglycaemic clamp.

CONCLUSION

A single event of insulin-induced hypoglycaemia led to an increase in markers of platelet activation and coagulation in people with early stages of type 2 diabetes on metformin therapy. However, the activation occurred with a delay and was evident 24 hours and 7 days after the actual hypoglycaemic episode.

Hypoglycemia and Dementia Risk in Older Patients with Type 2 Diabetes Mellitus: A Propensity-Score Matched Analysis of a Population-Based Cohort Study

BACKGROUND

Type 2 diabetes mellitus (T2DM) is associated with an increased risk for dementia. The effects of hypoglycemia on dementia are controversial. Thus, we evaluated whether hypoglycemia increases the risk for dementia in senior patients with T2DM.

METHODS

We used the Korean National Health Insurance Service Senior cohort, which includes >10% of the entire senior population of South Korea. In total, 5,966 patients who had ever experienced at least one episode of hypoglycemia were matched with those who had not, using propensity score matching. The risk of dementia was assessed through a survival analysis of matched pairs.

RESULTS

Patients with underlying hypoglycemic events had an increased risk for all-cause dementia, Alzheimer's dementia (AD), and vascular dementia (VaD) compared with those who had not experienced a hypoglycemic event (hazard ratio [HR], 1.254; 95% confidence interval [CI], 1.166 to 1.349; P<0.001 for all-cause dementia; HR, 1.264; 95% CI, 1.162 to 1.375; P<0.001 for AD; HR, 1.286; 95% CI, 1.110 to 1.490; P<0.001 for VaD). According to number of hypoglycemic episodes, the HRs of dementia were 1.170, 1.201, and 1.358 in patients with one hypoglycemic episode, two or three episodes, and more than three episodes, respectively. In the subgroup analysis, hypoglycemia was associated with an increased risk for dementia in both sexes with or without T2DM microvascular or macrovascular complications.

CONCLUSION

Our findings suggest that patients with a history of hypoglycemia have a higher risk for dementia. This trend was similar for AD and VaD, the two most important subtypes of dementia.

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.

Therapeutic Effects of Endogenous Incretin Hormones and Exogenous Incretin-Based Medications in Sepsis

BACKGROUND

Sepsis, a complex disorder characterized by a dysregulated immune response to an inciting infection, affects over one million Americans annually. Dysglycemia during sepsis hospitalization confers increased risk of organ dysfunction and death, and novel targets for the treatment of sepsis and maintenance of glucose homeostasis are needed. Incretin hormones are secreted by enteroendocrine cells in response to enteral nutrients and potentiate insulin release from pancreatic β cells in a glucose-dependent manner, thereby reducing the risk of insulin-induced hypoglycemia. Incretin hormones also reduce systemic inflammation in preclinical studies, but studies of incretins in the setting of sepsis are limited.

METHODS

In this bench-to-bedside mini-review, we detail the evidence to support incretin hormones as a therapeutic target in patients with sepsis. We performed a PubMed search using the medical subject headings "incretins," "glucagon-like peptide-1," "gastric inhibitory peptide," "inflammation," and "sepsis."

RESULTS

Incretin-based therapies decrease immune cell activation, inhibit proinflammatory cytokine release, and reduce organ dysfunction and mortality in preclinical models of sepsis. Several small clinical trials in critically ill patients have suggested potential benefit in glycemic control using exogenous incretin infusions, but these studies had limited power and were performed in mixed populations. Further clinical studies examining incretins specifically in septic populations are needed.

CONCLUSIONS

Targeting the incretin hormone axis in sepsis may provide a means of not only promoting euglycemia in sepsis but also attenuating the proinflammatory response and improving clinical outcomes.

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.