Glycaemia (haemoglobin A1c) and incident ischaemic stroke: the Atherosclerosis Risk in Communities (ARIC) Study

A thoracic CT imaging parameter predicting access difficulty in acute stroke thrombectomy

PURPOSE

The quick establishment of adequate vascular access is essential for the technical success of mechanical thrombectomy (MT). Focusing on shifts in aortic arch geometry and aging-related changes, we propose an imaging parameter for predicting access difficulty using chest CT.

METHODS

Patients with acute anterior circulation large-vessel occlusion who underwent MT from April 2020 to September 2021 were included in this retrospective multicenter observational study. The distance from the sternum to the ascending aorta (S-AAD) was defined as the surrogate marker of access difficulty. Access was defined as difficult when the time from femoral sheath placement to guiding catheter induction (guiding time: GT) ≥ 30 minutes, and the patients were dichotomized into groups with short GT (sGT: GT < 30 min) and long GT (lGT: GT ≥ 30 min).

RESULTS

One hundred fifteen patients were included. There were 12 patients (10.4 %) in lGT group. The median (IQR) S-AAD was 11.9 mm (6.3, 18.3 mm) in sGT group and 6.6 mm (4.0, 10.3 mm) in lGT group, and a significant difference in S-AAD was observed (P = 0.026). In multivariate analyses, dyslipidemia and S-AAD < 5 mm were significantly associated with difficult access (OR, 5.938 [95 % CI, 1.468, 24.022], P = 0.012 for dyslipidemia; OR, 5.147 [95 % CI, 1.267, 20.917], P = 0.022 for S-AAD < 5 mm).

CONCLUSION

S-AAD is a simple and reliable imaging parameter to predict access difficulty. This parameter may be helpful in selecting the appropriate devices and access routes in preinterventional practice.

Cellular metabolism changes in atherosclerosis and the impact of comorbidities

Cell activation and nutrient dysregulation are common consequences of atherosclerosis and its preceding risk factors, such as hypertension, dyslipidemia, and diabetes. These diseases may also impact cellular metabolism and consequently cell function, and the other way around, altered cellular metabolism can impact disease development and progression through altered cell function. Understanding the contribution of altered cellular metabolism to atherosclerosis and how cellular metabolism may be altered by co-morbidities and atherosclerosis risk factors could support the development of novel strategies to lower the risk of CVD. Therefore, we briefly review disease pathogenesis and the principles of cell metabolic pathways, before detailing changes in cellular metabolism in the context of atherosclerosis and comorbidities. In the hypoxic, inflammatory and hyperlipidemic milieu of the atherosclerotic plaque riddled with oxidative stress, metabolism shifts to increase anaerobic glycolysis, the pentose-phosphate pathway and amino acid use. We elaborate on metabolic changes for macrophages, neutrophils, vascular endothelial cells, vascular smooth muscle cells and lymphocytes in the context of atherosclerosis and its co-morbidities hypertension, dyslipidemia, and diabetes. Since causal relationships of specific key genes in a metabolic pathway can be cell type-specific and comorbidity-dependent, the impact of cell-specific metabolic changes must be thoroughly explored in vivo, with a focus on also systemic effects. When cell-specific treatments become feasible, this information will be crucial for determining the best metabolic intervention to improve atherosclerosis and its interplay with co-morbidities.

Association of Glycated Hemoglobin With Acute Ischemic Stroke in a Tertiary Care Center in a Tribal Region of Jharkhand

BACKGROUND

Increased glycated hemoglobin (HbA1c) levels have shown an association with an increased risk of stroke in patients admitted to a tertiary care center in Jharkhand.

OBJECTIVES

To find out and estimate the risk of acute ischemic stroke in patients with increased HbA1c levels compared with controls.

METHODS

This observational case-control study was conducted on patients admitted to the department of general medicine at a tertiary care center in Ranchi from June 2021 to November 2022. The patients included in this study were those aged 18 years or older and who were clinically and radiologically diagnosed with acute ischemic stroke. Only patients with a first episode of stroke were included, and patients with hemorrhagic stroke or transient ischemic attack were excluded from this study. An equal number of control participants were also included. Ion exchange high-performance liquid chromatography was used to perform the HbA1c tests. The same method was used to measure HbA1c levels in the controls. All findings were recorded in a Microsoft Excel sheet (Microsoft Corporation, Redmond, WA), and the data were analyzed using SPSS version 22.0 software (IBM Corp., Armonk, NY). After performing a descriptive statistical analysis, the findings were classified over a range of values and described accordingly. For each variable, an independent t-test was performed to compare the cases with the controls. A multivariable logistic regression analysis was used to choose the appropriate potential factors to determine the association in the multivariable analysis.

RESULTS

A total of 185 cases and 185 controls were included. The mean age of the cases with ischemic stroke was 63.77 ± 10.312, and that of the controls was 53.18 ± 11.35 (p < 0.01). The mean HbA1c level in the patients of acute ischemic stroke was 6.97 ± 1.84, and that of the controls was 5.99 ± 1.69 (p < 0.01). The mean random blood sugar (RBS) value in the ischemic stroke cases was 170.21 ± 84.16, and that of the controls was 150.03 ± 82.25 (p = 0.02). To compare the factors that were determined to be statistically significant between ischemic stroke cases and controls, a multivariable logistic regression analysis was performed. The HbA1c p-value was 0.01, the odds ratio (OR) was 1.280, and the 95% CI was 1.11-1.48. The other variables apart from HbA1c that were statistically significant between the ischemic stroke cases and the controls were age (p < 0.01, OR: 1.280, 95% CI: 1.06-1.11), hypertension (p = 0.618, OR: 1.130, 95% CI: 0.70-1.83), and high-density lipoprotein (p = 0.055, OR: 0.975, 95% CI: 0.95-1.00). When other cofounders were considered, it was concluded that with a 1% increase in HbA1c, the risk of stroke increases by 28% (OR: 1.28, 95% CI: 1.11-1.48). To compare the variables that were determined to be statistically significant between the control and ischemic stroke case groups, a multivariable logistic regression was used. The area under the receiver operating characteristic curve for HbA1c was 0.773 and RBS was 0.600.

CONCLUSION

This study shows that higher HbA1c levels in patients increase the risk of ischemic stroke. This study brings to light the need to screen the population periodically for diabetes by routinely testing for Hba1c in those who are at high risk of diabetes. Stroke risk can be reduced with early management and intervention. This study also concludes that HbA1c is a better predictor for assessing the risk of ischemic stroke than RBS levels.

Associations of combined polygenic risk score and glycemic status with atrial fibrillation, coronary artery disease and ischemic stroke

BACKGROUND

It is unknown whether high hemoglobin A1c (HbA1c) is associated with increases in the risk of cardiovascular disease among individuals with elevated genetic susceptibility. We aimed to investigate the association between HbA1c and atrial fibrillation (AF), coronary artery disease (CAD), and ischemic stroke according to the polygenic risk score (PRS).

METHODS

The UK Biobank cohort included 502,442 participants aged 40-70 years who were recruited from 22 assessment centers across the United Kingdom from 2006 to 2010. This study included 305,605 unrelated individuals with available PRS and assessed new-onset AF, CAD, and ischemic stroke. The participants were divided into tertiles based on the validated PRS for each outcome. Within each PRS tertiles, the risks of incident events associated with HbA1c levels were investigated and compared with HbA1c < 5.7% and low PRS. Data were analyzed from November 2022 to May 2023.

RESULTS

Of 305,605 individuals, 161,605 (52.9%) were female, and the mean (SD) age was 56.6 (8.1) years. During a median follow-up of 11.9 (interquartile range 11.1-12.6) years, the incidences of AF, CAD, and ischemic stroke were 4.6, 2.9 and 1.1 per 100 person-years, respectively. Compared to individuals with HbA1c < 5.7% and low PRS, individuals with HbA1c ≥ 6.5% and high PRS had a 2.67-times higher risk for AF (hazard ratio [HR], 2.67; 95% confidence interval (CI), 2.43-2.94), 5.71-times higher risk for CAD (HR, 5.71; 95% CI, 5.14-6.33) and 2.94-times higher risk for ischemic stroke (HR, 2.94; 95% CI, 2.47-3.50). In the restricted cubic spline models, while a U-shaped trend was observed between HbA1c and the risk of AF, dose-dependent increases were observed between HbA1c and the risk of CAD and ischemic stroke regardless PRS tertile.

CONCLUSIONS

Our results suggest that the nature of the dose-dependent relationship between HbA1c levels and cardiovascular disease in individuals with different PRS is outcome-specific. This adds to the evidence that PRS may play a role together with glycemic status in the development of cardiovascular disease.

Early rhythm control on diabetes-related complications and mortality in patients with type 2 diabetes mellitus and atrial fibrillation

AIMS

We evaluated the impact of early rhythm control (ERC) on diabetes-related complications and mortality in subjects with type 2 diabetes mellitus (T2DM) and atrial fibrillation (AF).

METHODS

This observational cohort study based on the Korean National Health Insurance Service claims database from 2009 to 2016, divided newly diagnosed AF patients with T2DM into ERC or usual care groups based on receiving rhythm control treatment within 1 year of AF diagnosis. The primary outcome was ischemic stroke, and the secondary outcomes were macro/microvascular complications, and all-cause death.

RESULTS

Among 47,509 subjects (mean age 66.7 ± 10.5 years; 61.8 % men; mean CHA2DS2-VASc score 4.6 ± 1.8; mean follow-up 4.3 ± 2.3 years; mean DM duration 5.6 ± 4.7 years), 23.1 % received ERC, and 76.9 % did not (usual care group). ERC was associated with lower risks of ischemic stroke, macrovascular and microvascular complications, and all-cause death compared to usual care (adjusted hazard ratios [95 % confidence interval]: 0.77 [0.70-0.85], 0.79 [0.73-0.86], 0.86 [0.82-0.90], and 0.92 [0.87-0.98], p < 0.001, <0.001, <0.001, and 0.012, respectively).

CONCLUSIONS

Early rhythm control was associated with reduced risks of diabetes-related complications and mortality in subjects with T2DM and AF. Rhythm control within 1 year of AF diagnosis with proper anticoagulation should be considered to prevent adverse outcomes.

Utilizing machine learning algorithms for the prediction of carotid artery plaques in a Chinese population

Background: Ischemic stroke is a significant global health issue, imposing substantial social and economic burdens. Carotid artery plaques (CAP) serve as an important risk factor for stroke, and early screening can effectively reduce stroke incidence. However, China lacks nationwide data on carotid artery plaques. Machine learning (ML) can offer an economically efficient screening method. This study aimed to develop ML models using routine health examinations and blood markers to predict the occurrence of carotid artery plaques. Methods: This study included data from 5,211 participants aged 18-70, encompassing health check-ups and biochemical indicators. Among them, 1,164 participants were diagnosed with carotid artery plaques through carotid ultrasound. We constructed six ML models by employing feature selection with elastic net regression, selecting 13 indicators. Model performance was evaluated using accuracy, sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV), F1 score, kappa value, and Area Under the Curve (AUC) value. Feature importance was assessed by calculating the root mean square error (RMSE) loss after permutations for each variable in every model. Results: Among all six ML models, LightGBM achieved the highest accuracy at 91.8%. Feature importance analysis revealed that age, Low-Density Lipoprotein Cholesterol (LDL-c), and systolic blood pressure were important predictive factors in the models. Conclusion: LightGBM can effectively predict the occurrence of carotid artery plaques using demographic information, physical examination data and biochemistry data.

Association of glycemic gap with stroke recurrence in patients with ischemic stroke

BACKGROUND

Glycemic gap, as a novel index of acute glycemic excursion, is associated with poor prognosis of different diseases. This study aimed to explore the association of the glycemic gap with long-term stroke recurrence in patients with ischemic stroke.

METHODS

This study included patients with ischemic stroke from the Nanjing Stroke Registry Program. The glycemic gap was calculated by subtracting the estimated average blood glucose from the blood glucose at admission. Multivariable Cox proportional hazards regression analysis was performed to explore the association between the glycemic gap and the risk of stroke recurrence. The Bayesian hierarchical logistic regression model was used to estimate the effects of the glycemic gap on stroke recurrence stratified by diabetes mellitus and atrial fibrillation.

RESULTS

Among 2734 enrolled patients, 381 (13.9%) patients experienced stroke recurrence during a median follow-up of 3.02 years. In multivariate analysis, glycemic gap (high group vs. median group) was associated with significantly increased risk for stroke recurrence (adjusted hazard ratio, 1.488; 95% confidence interval, 1.140-1.942; p = .003) and had varying effects on stroke recurrence depending on atrial fibrillation. The restricted cubic spline curve showed a U-shaped relationship between the glycemic gap and stroke recurrence (p = .046 for nonlinearity).

CONCLUSION

Our study found that the glycemic gap was significantly associated with stroke recurrence in patients with ischemic stroke. The glycemic gap was consistently associated with stroke recurrence across subgroups and had varying effects depending on atrial fibrillation.

Causal associations between blood pressure and the risk of myocardial infarction: A bidirectional Mendelian randomization study

Introduction

Many observational studies imply elevated blood pressure (BP) as a leading risk factor for incident myocardial infarction (MI), but whether this relationship is causal remains unknown. In this study, we used bidirectional Mendelian randomization (MR) to investigate the potential causal association of BP levels with the risk of MI.

Methods

Genetic variants associated with BP and MI traits were retrieved from the International Consortium of Blood Pressure (N = 7,57,601) and UKB (N = 3,61,194), obtaining 1,26,40,541 variants. We used two-sample MR (TSMR) analyses to examine the potential bidirectional causal association of systolic BP (SBP), diastolic BP (DBP) and pulse pressure (PP) with MI.

Results

The forward MR analysis identified a potentially causal association between MI and BP except PP[odds ratio (OR) SBP: 1.0008, P = 1.911 × 10−22; ORDBP: 1.0014, P = 1.788 × 10−28;odds ratio (OR)pp: 1.0092, P = 0.179]. However, the reverse analysis suggested no causal relation (betaSBP: 5.469, P = 0.763; betaDBP: 3.624, P = 0.588; betaPP: −0.074, P = 0.912). These findings were robust in sensitivity analyses such as the MR–Egger method, the maximum likelihood method and the MR pleiotropy residual sum and outlier test (MR-PRESSO). No horizontal pleiotropy (p = 0.869 for SBP, p = 0.109 for DBP and p = 0.978 for PP in the forward results and p = 0.168 for SBP, P = 0.892 for DBP and p = 0.989 for PP in the reverse results) was observed.

Conclusions

Elevated SBP or DBP levels increase the risk of MI, but there is no causal relationship between MI and changes in BP including PP. Independent of other risk factors, optimal BP control might represent an important therapeutic target for MI prevention in the general population.

Focal adhesion kinase-related pathways may be suppressed by metformin in vascular smooth muscle cells in high glucose conditions

Introduction

Cardiovascular diseases are known as one of the important causes of death in patients with diabetes mellitus. Metformin is used as an oral medication for reducing blood sugar. In this study, the effects of metformin were investigated on the FAK gene expression levels, pFAK protein values, cell viability and migration rate of VSMCs in high glucose conditions.

Materials and methods

The FAK gene expression levels and pFAK protein values were evaluated in VSMCs treated with different doses of metformin (1, 5 and 7 mM), based on cell viability using RT‐qPCR, western blotting and MTT techniques. The cellular migration was evaluated by scratch assay.

Results

The FAK gene expression levels reduced significantly in metformin‐treated VSMCs at 24 h and 48 h periods (p < .0008 and p < .0001, respectively). The pFAK protein values reduced significantly at 24 h (5 mM and 7 mM metformin doses) and 48 h periods (p < .001). In agreement with pFAK protein values, cellular migration reduced significantly at 24 h and 48 h periods (p < .001).

Conclusion

The results showed that metformin may suppress the proliferation and migration of VSMCs via FAK‐related pathways and may retard the progression of vessel stenosis in diabetes.

Relation of Hemoglobin A1C Levels to Risk of Ischemic Stroke and Mortality in Patients With Diabetes Mellitus and Atrial Fibrillation

Diabetes mellitus (DM) is associated with an increased risk of complications in atrial fibrillation (AF). This study aimed to assess the incidence and risks of ischemic stroke and mortality according to baseline HbA1c levels in patients with DM and AF. We conducted a cohort study using Clalit Health Services electronic medical records. The study population included all Clalit Health Services members aged ≥25 years, with the first diagnosis of AF between January 1, 2010, and December 31, 2016, who had a diagnosis of DM. The risk of stroke and all-cause death were compared according to HbA1c levels at the time of AF diagnosis: <7.0%, between 7% and 9%, and ≥9%. A total of 44,451 patients with DM and AF were identified. The median age was 75 years (interquartile 65 to 83), and 52.5% were women. During a mean follow-up of 38 months, higher levels of HbA1c were associated with an increased risk of stroke with a dose-dependent response when compared with patients with HbA1c <7% (Adjusted hazard ratio [aHR] =1.30 [95% confidence interval 1.10 to 2.05] for levels between 7% and 9% and 1.60 (95% confidence interval 1.25 to 2.03) for HbA1c >9%, even after adjusting for CHA₂DS₂-Vasc risk factors and use of oral anticoagulants. The risk for overall mortality was significantly higher in the HBA1C >9% group (aHR = 1.17 [1.07 to 1.28]). In conclusion, in this cohort of patients with AF and DM, HbA1c levels were associated with the risk of stroke in a dose-dependent manner even after accounting for other recognized risk factors for stroke.

Diabetes and Ischemic Stroke: An Old and New Relationship an Overview of the Close Interaction between These Diseases

Diabetes mellitus is a comprehensive expression to identify a condition of chronic hyperglycemia whose causes derive from different metabolic disorders characterized by altered insulin secretion or faulty insulin effect on its targets or often both mechanisms. Diabetes and atherosclerosis are, from the point of view of cardio- and cerebrovascular risk, two complementary diseases. Beyond shared aspects such as inflammation and oxidative stress, there are multiple molecular mechanisms by which they feed off each other: chronic hyperglycemia and advanced glycosylation end-products (AGE) promote ‘accelerated atherosclerosis’ through the induction of endothelial damage and cellular dysfunction. These diseases impact the vascular system and, therefore, the risk of developing cardio- and cerebrovascular events is now evident, but the observation of this significant correlation has its roots in past decades. Cerebrovascular complications make diabetic patients 2–6 times more susceptible to a stroke event and this risk is magnified in younger individuals and in patients with hypertension and complications in other vascular beds. In addition, when patients with diabetes and hyperglycemia experience an acute ischemic stroke, they are more likely to die or be severely disabled and less likely to benefit from the one FDA-approved therapy, intravenous tissue plasminogen activator. Experimental stroke models have revealed that chronic hyperglycemia leads to deficits in cerebrovascular structure and function that may explain some of the clinical observations. Increased edema, neovascularization, and protease expression as well as altered vascular reactivity and tone may be involved and point to potential therapeutic targets. Further study is needed to fully understand this complex disease state and the breadth of its manifestation in the cerebrovasculature.

Relationships Among Gut Microbiota, Ischemic Stroke and Its Risk Factors: Based on Research Evidence

Stroke is a highly lethal disease and disabling illness while ischemic stroke accounts for the majority of stroke. It has been found that inflammation plays a key role in the initiation and progression of stroke, and atherosclerotic plaque rupture is considered to be the leading cause of ischemic stroke. Furthermore, chronic inflammatory diseases, such as obesity, type 2 diabetes mellitus (T2DM) and hypertension, are also considered as the high-risk factors for stroke. Recently, the topic on how gut microbiota affects human health has aroused great concern. The initiation and progression of ischemic stroke has been found to have close relation with gut microbiota dysbiosis. Hence, this manuscript briefly summarizes the roles of gut microbiota in ischemic stroke and its related risk factors, and the practicability of preventing and alleviating ischemic stroke by reconstructing gut microbiota.

Upregulation of TGF-β type II receptor in high glucose-induced vascular smooth muscle cells

BACKGROUND

Mortality in patients with diabetes mellitus is estimated above 65% due to cardiovascular diseases. The aim of study was to investigate the effects of high-glucose conditions on TGF-β type II receptor (TGFBR2) expression levels, cell viability, and migration rate in vascular smooth muscle cells (VSMCs).

METHODS

VSMCs were incubated in 30 mM and 50 mM of glucose for 24 h, 48 h, and 72 h periods. The gene and protein expression levels were investigated by Real-time qRT-PCR and western blotting techniques, respectively. The cell viability was evaluated by MTT assay. VSMC migration rate was also studied by wound healing assay.

RESULTS

The TGFBR2 gene and protein expression levels were significantly upregulated in all the groups treated with glucose in 24 h, 48 h, and 72 h periods. The cell viability was not significantly affected in values of 30 mM and 50 mM of glucose. The increase of migration rate of VSMCs was not significant.

CONCLUSION

The results suggested the increased expression levels of TGFBR2 in the response to high glucose conditions may modulate the cellular events through the signaling pathway network in VSMCs.

Association of glycated hemoglobin A1c levels with cardiovascular outcomes in the general population: results from the BiomarCaRE (Biomarker for Cardiovascular Risk Assessment in Europe) consortium

BACKGROUND

Biomarkers may contribute to improved cardiovascular risk estimation. Glycated hemoglobin A1c (HbA1c) is used to monitor the quality of diabetes treatment. Its strength of association with cardiovascular outcomes in the general population remains uncertain. This study aims to assess the association of HbA1c with cardiovascular outcomes in the general population.

METHODS

Data from six prospective population-based cohort studies across Europe comprising 36,180 participants were analyzed. HbA1c was evaluated in conjunction with classical cardiovascular risk factors (CVRFs) for association with cardiovascular mortality, cardiovascular disease (CVD) incidence, and overall mortality in subjects without diabetes (N = 32,496) and with diabetes (N = 3684).

RESULTS

Kaplan-Meier curves showed higher event rates with increasing HbA1c levels (log-rank-test: p < 0.001). Cox regression analysis revealed significant associations between HbA1c (in mmol/mol) in the total study population and the examined outcomes. Thus, a hazard ratio (HR) of 1.16 (95% confidence interval (CI) 1.02-1.31, p = 0.02) for cardiovascular mortality, 1.13 (95% CI 1.03-1.24, p = 0.01) for CVD incidence, and 1.09 (95% CI 1.02-1.17, p = 0.01) for overall mortality was observed per 10 mmol/mol increase in HbA1c. The association with CVD incidence and overall mortality was also observed in study participants without diabetes with increased HbA1c levels (HR 1.12; 95% CI 1.01-1.25, p = 0.04) and HR 1.10; 95% CI 1.01-1.20, p = 0.02) respectively. HbA1c cut-off values of 39.9 mmol/mol (5.8%), 36.6 mmol/mol (5.5%), and 38.8 mmol/mol (5.7%) for cardiovascular mortality, CVD incidence, and overall mortality, showed also an increased risk.

CONCLUSIONS

HbA1c is independently associated with cardiovascular mortality, overall mortality and cardiovascular disease in the general European population. A mostly monotonically increasing relationship was observed between HbA1c levels and outcomes. Elevated HbA1c levels were associated with cardiovascular disease incidence and overall mortality in participants without diabetes underlining the importance of HbA1c levels in the overall population.

Impact of Diabetes Mellitus on Stroke and Survival in Patients With Atrial Fibrillation

Although diabetes mellitus (DM) has been established as a risk factor for developing atrial fibrillation (AF) and is a known risk factor for stroke, it is unclear whether the presence or duration of DM is the primary adverse influence on the clinical course of AF. We retrospectively analyzed patients diagnosed with incident AF to examine the impact of DM on ischemic stroke and all-cause mortality. The diagnosis of DM was established by ICD-9 codes and review of medical records. To account for the significant differences in baseline characteristics of patients with and without diabetes, we matched 909 AF patients with DM with 909 AF patients without DM using propensity score matching based on 26 baseline variables. Cox regression analysis was used to identify independent factors associated with ischemic stroke and mortality. The mean age of the propensity matched cohort was 74 ± 11.5 years and 55.4% were male. Over a median follow-up period of 5.4 years (maximum 23.9 years), cumulative survival was significantly lower for patients with DM than those without DM; Log-rank p <0.001. In the propensity-matched comparison, the risk of mortality was significantly higher in the DM group compared with the non-DM group (hazard ratio 1.25; 95% confidence interval 1.12 to 1.69; p <0.001). Likewise, patients with DM had a higher risk of stroke (hazard ratio 1.32; 95% confidence interval 1.02 to 1.69; p = 0.03). Duration of DM was not associated with increased risk for stroke or mortality. In conclusion, the co-morbidity of DM represents an independent predictor of reduced survival and further highlights the excess risk of thromboembolism in patients with AF.

Diabetic atherosclerosis: is there a role for the hypoxia-inducible factors?

Atherosclerosis is a major cause of mortality worldwide and is driven by multiple risk factors, including diabetes. Diabetes is associated with either an insulin deficiency in its juvenile form or with insulin resistance and obesity in Type 2 diabetes mellitus, and the latter is clustered with other comorbidities to define the metabolic syndrome. Diabetes and metabolic syndrome are complex pathologies and are associated with cardiovascular risk via vascular inflammation and other mechanisms. Several transcription factors are activated upon diabetes-driven endothelial dysfunction and drive the progression of atherosclerosis. In particular, the hypoxia-inducible factor (HIF) transcription factor family is a master regulator of endothelial biology and is raising interest in the field of atherosclerosis. In this review, we will present an overview of studies contributing to the understanding of diabetes-driven atherosclerosis, integrating the role of HIF in this disease with the knowledge of its functions in metabolic syndrome and diabetic scenario.

The use of glycosylated hemoglobin (HbA1c) as a predictor of the severity of acute coronary syndrome among diabetic patients

BACKGROUND

Acute myocardial infarction in patients with type two diabetes mellitus is usually present with multiple vessel lesions during coronary angiography. The underlying mechanism remains unexplored, and there is a deficiency of serum predictive markers. Glycosylated hemoglobin (HbA1c), which is a critical measure of glycemic control, could be used as a reliable predictor of the severity of ACS.

MATERIALS AND METHODS

This is a prospective descriptive comparative hospital-based study measured the correlation between levels of HbA1c and the severity of ACS using the modified Gensini score (MGS). A total of 85 patients were enrolled in this study in the period between September and November 2019. The MGS depends on the number of vessels which are stenosed with the degree of stenosis more than 50% of their lumen. Data was analyzed using SPSS V. 2018. Chi-square test was used.

RESULTS

The total number of enrolled patients was 85. Dyslipidemia was found among 63 (74.1%) patients, and 52 (69.4%) of the patients were noted to have hypertension. A total of 19 (22.4%) patients were smokers. About 59 (69.4%) patients had a family history of IHD, and 22 patients (25.9%) had a history of IHD. STEMI was the main ECG finding 54 (63.5%). Modified Gensini score depicted that 32 (35.29%) had mild acute coronary syndrome, 23(27.06%) had moderate, and 30 (37.65%) had severe acute coronary syndrome. HbA1c was significantly positively correlated with the severity of ACS among diabetic patients (P value = 0.000).

CONCLUSION

In diabetic patients with acute coronary syndrome, HbA1c levels can be used as a predictor for the severity of CAD.

Glycemic status and risks of thromboembolism and major bleeding in patients with atrial fibrillation

Background

Studies specifically examining the association between glycated hemoglobin A1c (HbA1c) levels and ischemic stroke/systemic thromboembolism (IS/SE) risk in atrial fibrillation (AF) patients are limited. Here, we investigated the association between HbA1c levels and the risk of IS/SE, as well as major bleeding, among AF patients with or without oral anticoagulants (OACs). We also compared the effectiveness and safety of warfarin and direct oral anticoagulants (DOACs) in different HbA1c categories.

Methods

We utilized medical data from a multi-center healthcare provider in Taiwan, which included 34,036 AF patients with serum HbA1c data available within 3 months after AF being diagnosed. Patients were divided into seven study groups according to their HbA1c levels: < 5.4%, 5.4%–5.6%, 5.7%–5.9%, 6.0%–6.4%, 6.5%–6.9%, 7.0%–7.9%, and ≥ 8.0%. The risks of IS/SE and major bleeding were compared among the groups after adjusting for baseline stroke and bleeding risk factors.

Results

Compared with the patients with HbA1c level < 5.4%, IS/SE risk significantly increased at HbA1c levels higher than 6.5% [adjusted hazard ratio (HR): 1.20, 95% confidence interval (CI): 1.00–1.43 for HbA1c level 6.5%–6.9%; 1.32, (95% CI 1.11–1.57) for HbA1c level 7.0%–7.9%; and 1.48 (95% CI 1.25–1.76) for HbA1c level ≥ 8.0%]. These results were generally consistent in AF patients without OACs (n = 24,931). However, among 9105 patients receiving OACs, IS/SE risk was not higher for patients having higher HbA1c levels. The risk of major bleeding was comparable across all HbA1c categories. Compared with warfarin, DOACs were associated with lower risks of IS/SE (adjusted HR: 0.61, 95% CI 0.49–0.75) and major bleeding (adjusted HR: 0.30, 95% CI 0.21–0.42) without interactions across different HbA1c categories (all P interactions > 0.05).

Conclusion

For AF patients, IS/SE risk significantly increased once HbA1c levels exceeded 6.5%, and OACs may attenuate these associations. Compared with warfarin, DOACs were more effective and safer across broad HbA1c categories. Therefore, in addition to prescribing DOACs when indicated, more aggressive glycemic control to achieve an HbA1c level < 6.5% may be considered for eligible AF patients and should be tested in further prospective studies.

Newly detected atrial fibrillation is associated with cortex-involved ischemic stroke

Background:

Both cortical and cortical-subcortical (cortex-involved) lesions are typically associated with embolic stroke, of which atrial fibrillation (AF) is the common cause. The aim of this study was to find out the associations between cortex-involved stroke, vascular risk factors, and the subtypes (discovery time and duration) of AF.

Methods:

This was an imaging study of the China Atrial Fibrillation Screening in Acute Ischemic Stroke Patients (CRIST) trial. Between October 2013 and June 2015, 1511 acute ischemic stroke or transient ischemic attack (TIA) patients within 7 days after stroke onset at 20 Chinese hospitals were enrolled in this prospective, multicenter cohort, cross-sectional study. The final analysis of this sub-study included 243 patients with AF with required magnetic resonance imaging (MRI) sequences. AF was diagnosed by 6-day Holter monitoring and classified by duration of 24 h. Two stroke specialists blinded to the clinical information reviewed MRI (diffusion-weighted MRI). The third stroke specialists, also blinded to the clinical information, assessed the conflicts. Adjusted large artery atherosclerosis as confounding factor, the associations between cortex-involved lesions, vascular risk factors, and the subtype of AF were evaluated by univariate and multivariate regression analyses.

Results:

Of 243 acute ischemic stroke patients with AF, 190 were known AF and 53 were newly detected AF. There were 28 patients with AF persistent >24 h and 25 persistent ≤24 h in newly detected AF. Patients with newly detected AF were likely to have a fewer history of stroke or TIA (16.98% vs. 36.31%, P = 0.008) and lower fasting blood glucose (5.91 ± 1.83 mmol/L vs. 6.75 ± 3.83 mmol/L, P = 0.030) than patients with known AF. Among these 243 patients, 102 (41.98%) patients were with cortex-involved lesions. Cortex-involved lesions were significantly related to newly detected AF persistent >24 h (odds ratio [OR]: 4.517, 95% confidence interval [CI]: 1.490–13.696, P = 0.008), proteinuria (OR: 3.431, 95% CI: 1.530–7.692, P = 0.021), and glycosylated hemoglobin (OR: 0.632, 95% CI: 0.464–0.861, P = 0.004).

Conclusions:

Compared to previously known AF, newly detected AF persistent >24 h was associated with cortex-involved ischemic stroke.

Clinical trial registration:

NCT02156765, https://clinicaltrials.gov/ct2/show/record/NCT02156765

[Diabetes mellitus and cognitive impairment]

The review discusses literature data and the results of our own studies on the effect of diabetes on cognitive functions and cerebrovascular pathology, as well as possible ptogenetic mechanisms for the implementation of this effect. The results of studies on the effects of antidiabetic drugs on cognitive function are presented.

Association Between Midlife Risk Factors and Late-Onset Epilepsy: Results From the Atherosclerosis Risk in Communities Study

Importance

The incidence of epilepsy is higher in older age than at any other period of life. Stroke, dementia, and hypertension are associated with late-onset epilepsy; however, the role of other vascular and lifestyle factors remains unclear.

Objective

To identify midlife vascular and lifestyle risk factors for late-onset epilepsy.

Design, Setting, and Participants

The Atherosclerosis Risk in Communities (ARIC) study is a prospective cohort study of 15 792 participants followed up since 1987 to 1989 with in-person visits, telephone calls, and surveillance of hospitalizations (10 974 invited without completing enrollment). The ARIC is a multicenter study with participants selected from 4 US communities. This study included 10 420 black or white participants from ARIC with at least 2 years of Medicare fee-for-service coverage and without missing baseline data. Data were analyzed betweeen April 2017 and May 2018.

Exposures

Demographic, vascular, lifestyle, and other possible epilepsy risk factors measured at baseline (age 45-64 years) were evaluated in multivariable survival models including demographics, vascular risk factors, and lifestyle risk factors.

Main Outcomes and Measures

Time to development of late-onset epilepsy (2 or more International Classification of Diseases, Ninth Revision codes for epilepsy or seizures starting at 60 years or older in any claim [hospitalization or outpatient Medicare through 2013]), with first code for seizures after at least 2 years without code for seizures.

Results

Of the 10 420 total participants (5878 women [56.4%] and 2794 black participants [26.8%]; median age 55 years at first visit), 596 participants developed late-onset epilepsy (3.33 per 1000 person-years). The incidence was higher in black than in white participants (4.71; 95% CI, 4.12-5.40 vs 2.88; 95% CI, 2.60-3.18 per 1000 person-years). In multivariable analysis, baseline hypertension (hazard ratio [HR], 1.30; 95% CI, 1.09-1.55), diabetes (HR, 1.45; 95% CI, 1.17-1.80), smoking (HR, 1.09; 95% CI, 1.01-1.17), apolipoprotein E ε4 genotype (1 allele HR, 1.22; 95% CI, 1.02-1.45; 2 alleles HR, 1.95; 95% CI, 1.35-2.81), and incident stroke (HR, 3.38; 95% CI, 2.78-4.10) and dementia (HR, 2.56; 95% CI, 2.11-3.12) were associated with an increased risk of late-onset epilepsy, while higher levels of physical activity (HR, 0.90; 95% CI, 0.83-0.98) and moderate alcohol intake (HR, 0.72; 95% CI, 0.57-0.90) were associated with a lower risk. Results were similar after censoring individuals with stroke or dementia.

Conclusions and Relevance

Potentially modifiable risk factors in midlife and the APOE ε4 genotype were positively associated with risk of developing late-onset epilepsy. Although stroke and dementia were both associated with late-onset epilepsy, vascular and lifestyle risk factors were significant even in the absence of stroke or dementia.

Impact of obesity-induced type 2 diabetes on long-term outcomes following stroke

Diabetes is associated with poor recovery profiles following stroke. The pathophysiological mechanisms by which diabetes mediates neurological recovery after stroke are debatable. A recent paper published in the Clinical Science by Pintana et al. (Clinical Science (2019)133, 1367-1386) provides a possible explanation for the underlying mechanisms of poor long-term motor recovery after stroke in obesity-induced diabetes animal model. Authors report that stroke-induced neurogenesis and parvalbumin (PV)+ interneuron-mediated neuroplasticity is severely impaired due to obesity-induced type 2 diabetes (T2D). Poor long-term motor recovery after stroke in comorbid obese and diabetic mice was not associated with stroke-induced grey or white matter damage. Understanding these mechanisms is crucial to develop therapeutic strategies to improve recovery in the obesity-induced diabetic population. The strength of the present study lies in the use of a comorbid obese/diabetic animal model, which is more likely to reflect the clinical scenario. However, these findings should be understood from the context of this specific animal model and whether these findings hold true for another variant of the obesity/T2D model warrants further consideration. This is an interesting study from the perspective of understanding the stroke pathology in T2D; however, the interaction of microvascular changes (including vascular modelling, angiogenesis), oxidative stress and insulin resistance (IR) associated with T2D and poor recovery profile merit further discussions. Given the increasing burden of obesity, diabetes and/or stroke globally, understanding of mechanisms may be useful in developing cardiovascular risk management pathways in this subgroup of population who are at increased risk of poor clinical outcomes following acute stroke.

Prevalence of diabetes and its effects on stroke outcomes: A meta-analysis and literature review

AIMS/INTRODUCTION

Diabetes mellitus is an established risk factor for stroke and maybe associated with poorer outcomes after stroke. The aims of the present literature review were to determine: (i) the prevalence of diabetes in acute stroke patients through a meta-analysis; (ii) the association between diabetes and outcomes after ischemic and hemorrhagic stroke; and (iii) to review the value of glycated hemoglobin and admission glucose-based tests in predicting stroke outcomes.

MATERIALS AND METHODS

Ovid MEDLINE and EMBASE searches were carried out to find studies relating to diabetes and inpatient stroke populations published between January 2004 and April 2017. A meta-analysis of the prevalence of diabetes from included studies was undertaken. A narrative review on the associations of diabetes and different diagnostic methods on stroke outcomes was carried out.

RESULTS

A total of 66 eligible articles met inclusion criteria. A meta-analysis of 39 studies (n = 359,783) estimated the prevalence of diabetes to be 28% (95% confidence interval 26-31). The rate was higher in ischemic (33%, 95% confidence interval 28-38) compared with hemorrhagic stroke (26%, 95% confidence interval 19-33) inpatients. Most, but not all, studies found that acute hyperglycemia and diabetes were associated with poorer outcomes after ischemic or hemorrhagic strokes: including higher mortality, poorer neurological and functional outcomes, longer hospital stay, higher readmission rates, and stroke recurrence. Diagnostic methods for establishing diagnosis were heterogeneous between the reviewed studies.

CONCLUSIONS

Approximately one-third of all stroke patients have diabetes. Uniform methods to screen for diabetes after stroke are required to identify individuals with diabetes to design interventions aimed at reducing poor outcomes in this high-risk population.

The initial glycemic variability is associated with early neurological deterioration in diabetic patients with acute ischemic stroke

The association between glycemic variability and early neurological deterioration (END) in acute ischemic stroke remains unclear. This study attempted to explore whether initial glycemic variability increases END in diabetic patients with acute ischemic stroke. We enrolled type 2 diabetic patients undergoing acute ischemic stroke from November 2015 to November 2016. A total of 336 patients within 72 h from stroke onset were included. The serum glucose levels were checked four times per day during the initial 3 hospital days. The standard deviation of blood glucose (SDBG) values and the mean amplitude of glycemic excursions (MAGE) were calculated for glycemic variability. END was defined as an increase in the National Institutes of Health Stroke Scale (NIHSS) ≥ 2 points between hospital days 0 and 5. The frequencies of END and HbA1c were significantly different in subjects grouped according to tertiles of MAGE (9.09, 12.07 and 50.00%, p < 0.001 for END; 7.36 ± 1.91, 7.83 ± 1.93 and 8.56 ± 1.79, p < 0.001 for HbA1c). Compared to patients without END, patients with END had significantly higher HbA1c levels (8.30 ± 1.92 vs 7.80 ± 1.93, p = 0.043), increased SDBG (3.42 ± 1.14 vs 2.60 ± 0.96, p < 0.001), and increased MAGE (6.46 ± 2.09 vs 4.59 ± 1.91, p < 0.001). In a multivariable logistic regression, stroke etiology (OR 0.675; 95% CI 0.485-0.940, p = 0.020), baseline NIHSS (OR 1.086; 95% CI 1.004-1.175, p = 0.040), and MAGE (OR 1.479; 95% CI 1.162-1.882, p = 0.001) were significantly associated with END. Initial glycemic variability is associated with END in diabetic patients with acute ischemic stroke.

The CHA2DS2-VASc score: Not as simple as it seems

The CHA₂DS₂-VASc score has been widely adopted as a risk stratification tool for strokes in patients with atrial fibrillation and to help in deciding when anticoagulation therapy for stroke prophylaxis may be beneficial. The score as a whole has been well validated and has been included in the current major practice guidelines. An advantage of the CHA₂DS₂-VASc score is its ease of use, allowing clinicians to quickly estimate risk based on a short set of criteria. However, the benefit of simplicity may also be a weakness. Studies on individual components of the score suggest that only a subset of patients deemed to be at risk based on the current definition are actually at risk for stroke. Thus, users of the score should be aware of the nuances based on available evidence and avoid over-generalization. Accurate assessment of stroke risk has important clinical implications as it influences decision-making on initiation of anticoagulation.

Burden of high blood pressure as a contributing factor to stroke in the Japanese community-based diabetic population

Diabetes mellitus is characterized by alterations in blood glucose (BG) metabolism, and glycated hemoglobin (HbA₁c) has been widely used as a marker of the BG concentration. Diabetes often coexists with high blood pressure (BP). High BP and hyperglycemia are well-known risk factors of stroke. We examined the extent to which the increased risk of stroke in diabetic individuals is attributable to BP and BG using prospectively collected data from the Japanese general population. During an average 8.3 ± 2.2 years of follow-up, out 1606 diabetic individuals aged ≥40 years who were free of cardiovascular disease, 119 participants (7.4%) developed stroke. In multivariable analysis, a significant difference in the risk of incident stroke was noted among the BP categories, including normotension (BP1), prehypertension (BP2), and hypertension (BP3; P for trend = 0.001). By contrast, no difference was noted among the BG categories, including HbA₁c levels <7.0% (HB1), 7.0–7.9% (HB2), and ≥8.0% (HB3; P for trend = 0.430). Compared with the category that included both BP1 and HB1, the population-attributable fraction (PAF) for stroke incidence was 52.0% from the BP2 and BP3 categories and 24.1% from the HB2 and HB3 categories, and the increased incidence from the HB2 and HB3 categories was mostly caused from coexistent BP2 and BP3 categories. In conclusion, in the Japanese community-based diabetic population, concomitant BP elevation largely contributes to the increased incidence of stroke and links BG elevation, as indicated by HbA₁c, to the increased risk of stroke.

Declining Rates of Hospitalization for Selected Cardiovascular Disease Conditions Among Adults Aged ≥35 Years With Diagnosed Diabetes, U.S., 1998-2014

OBJECTIVE

Reductions in heart attack and stroke hospitalizations are well documented in the U.S. population with diabetes. We extended trend analyses to other cardiovascular disease (CVD) conditions, including stroke by type, and used four additional years of data.

RESEARCH DESIGN AND METHODS

Using 1998-2014 National (Nationwide) Inpatient Sample (NIS) data, we estimated the number of discharges having acute coronary syndrome (ACS) (ICD-9 codes 410-411), cardiac dysrhythmia (427), heart failure (428), hemorrhagic stroke (430-432), or ischemic stroke (433.x1, 434, and 436) as first-listed diagnosis and diabetes (250) as secondary diagnosis. Hospitalization rates for adults aged ≥35 years were calculated using estimates from the population with and the population without diabetes from the National Health Interview Survey (NHIS) and age-adjusted to the 2000 U.S. standard population. Joinpoint regression was used to analyze trends and calculate an average annual percentage change (AAPC) with 95% confidence limits (CLs).

RESULTS

From 1998 to 2014, in the population with diabetes, age-adjusted hospitalization rates declined significantly for ACS (AAPC -4.6% per year [95% CL -5.3, -3.8]), cardiac dysrhythmia (-0.7% [-1.1, -0.2]), heart failure (-3.6% [-4.6, -2.7]), hemorrhagic stroke (-1.1% [-1.4, -0.7]), and ischemic stroke (-2.9% [-3.9, -1.8]). In the population without diabetes, rates also declined significantly for these conditions, with the exception of dysrhythmia. By 2014, rates in the population with diabetes population remained two to four times as high as those for the population without diabetes, with the largest difference in heart failure rates.

CONCLUSIONS

CVD hospitalization rates declined significantly in both the population with diabetes and the population without diabetes. This may be due to several factors, including new or more aggressive treatments and reductions in CVD risk factors and CVD incidence.

[Evaluation and perioperative management of patients with diabetes mellitus. A challenge for the anesthesiologist]

Diabetes mellitus (DM) is characterized by alteration in carbohydrate metabolism, leading to hyperglycemia and increased perioperative morbidity and mortality. It evolves with diverse and progressive physiological changes, and the anesthetic management requires attention regarding this disease interference in multiple organ systems and their respective complications. Patient's history, physical examination, and complementary exams are important in the preoperative management, particularly glycosylated hemoglobin (HbA1c), which has a strong predictive value for complications associated with diabetes. The goal of surgical planning is to reduce the fasting time and maintain the patient's routine. Patients with Type 1 DM must receive insulin (even during the preoperative fast) to meet the basal physiological demands and avoid ketoacidosis. Whereas patients with Type 2 DM treated with multiple injectable and/or oral drugs are susceptible to develop a hyperglycemic hyperosmolar state (HHS). Therefore, the management of hypoglycemic agents and different types of insulin is fundamental, as well as determining the surgical schedule and, consequently, the number of lost meals for dose adjustment and drug suspension. Current evidence suggests the safe target to maintain glycemic control in surgical patients, but does not conclude whether it should be obtained with either moderate or severe glycemic control.

Evaluation and perioperative management of patients with diabetes mellitus. A challenge for the anesthesiologist

Diabetes mellitus (DM) is characterized by alteration in carbohydrate metabolism, leading to hyperglycemia and increased perioperative morbidity and mortality. It evolves with diverse and progressive physiological changes, and the anesthetic management requires attention regarding this disease interference in multiple organ systems and their respective complications. Patient's history, physical examination, and complementary exams are important in the preoperative management, particularly glycosylated hemoglobin (HbA1c), which has a strong predictive value for complications associated with diabetes. The goal of surgical planning is to reduce the fasting time and maintain the patient's routine. Patients with Type 1 DM must receive insulin (even during the preoperative fast) to meet the basal physiological demands and avoid ketoacidosis. Whereas patients with Type 2 DM treated with multiple injectable and/or oral drugs are susceptible to develop a hyperglycemic hyperosmolar state (HHS). Therefore, the management of hypoglycemic agents and different types of insulin is fundamental, as well as determining the surgical schedule and, consequently, the number of lost meals for dose adjustment and drug suspension. Current evidence suggests the safe target to maintain glycemic control in surgical patients, but does not conclude whether it should be obtained with either moderate or severe glycemic control.

Assessment of gender-related differences in vitamin D levels and cardiovascular risk factors in Saudi patients with type 2 diabetes mellitus

Diabetes is a major risk factor for cardiovascular disease (CVD) including stroke, coronary heart disease, and peripheral artery disease. It remains a leading cause of mortality throughout the world, affecting both women and men. This investigation was aimed to study gender based differences in cardiovascular risk factors of adult population with type-2 diabetes mellitus (T2DM) and to check the correlation between serum HbA1C, lipid profile and serum vitamin D levels, in T2DM patients of Riyadh, Saudi Arabia. This hospital-based cross-sectional study involving subjects was divided into two gender based groups; normal male (800), diabetic male (800) and normal female (800) and T2DM females (800). Blood samples were analyzed for fasting glucose (FBG), HbA1c, total cholesterol (TC), triglycerides (Tg), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and serum levels of 25(OH)-vitamin D in all groups. All the glycemic control parameters and lipid profile parameters were found to be significantly different in diabetic vs non-diabetic group (p < 0.001) in both genders. The results also show that vitamin D concentration decreased significantly (p < 0.001) in diabetic patients than the healthy individuals in both the genders. Vitamin-D and HbA1C were negatively correlated in both males and females in T2DM patients and significant at P < 0.05. Our study reveals that dyslipidemia remains one of the major risk factors of CVD in T2DM. In addition to dyslipidemia, decreased levels of vitamin-D associated with increased HbA1C alarms the early diagnosis of Type 2 Diabetes.

Early New Ischemic Lesions Located Outside the Initially Affected Vascular Territory Appear More Often in Stroke Patients with Elevated Glycated Hemoglobin (HbA1c)

Background

Early new ischemic lesions are common in patients with an acute ischemic stroke. These new ischemic lesions may represent the natural course of the initial stroke or de novo events.

Objective

We hypothesized that early new ischemic lesions located outside the initially affected vascular territory would point at de novo events. Therefore, we differentiated new ischemic lesions located outside the initially affected vascular territory from those occurring only inside the initially affected vascular territory to identify risk factors that are associated with de novo events.

Methods

Stroke patients underwent three magnetic resonance imaging examinations (at 3-T): on admission, on the next day and 4–7 days after symptom onset (clinicaltrials.gov: NCT00715533). Diffusion-weighted imaging (DWI) lesions were delineated, coregistered, and then analyzed for new hyperintensities on follow-up examinations by raters blinded to clinical details. Patients were classified as having “new distant lesions” if new DWI lesions appeared outside or both outside and inside the initially affected vascular territory or “new local lesions” if they were only inside.

Results

115 patients with early new DWI lesions constitute the study population. Sixteen patients (14%) had new distant lesions and 99 patients (86%) had new local lesions. In comparison between patients with new distant and new local lesions, patients with new distant lesions had significantly more often elevated glycated hemoglobin (HbA1c ≥ 6.5%; p = 0.022).

Conclusion

Our data indicate that patients with elevated HbA1c have an increased risk for new, de novo ischemic lesions in the acute phase after an ischemic stroke.

HbA1c in relation to incident diabetes and diabetes-related complications in non-diabetic adults at baseline

AIMS

We compared the utility of glycated hemoglobin (HbA_1c) and oral glucose tolerance (oGTT) in non-diabetic patients for identifying incident diabetes; all-cause mortality; cardiovascular disease (CVD) mortality; CVD, coronary heart disease (CHD), and ischemic stroke events; and diabetes microvascular complications.

METHODS

Data from a New Zealand community setting were prospectively linked to hospitalization, mortality, pharmaceutical and laboratory test results data. After applying exclusion criteria (prior laboratory diagnosis or history of drug treatment for diabetes or hospitalization for diabetes or CVD event), there were 31,148 adults who had an HbA_1c and 2-h 75g oGTT. HbA_1c was measured by ion-exchange high-performance liquid chromatography, and glucose using a commercial enzymatic method. We compared glycemic measures and outcomes using multivariable Cox proportional hazards regression.

RESULTS

The median follow-up time was 4years (range 0 to 13). The mean age was 57·6years and 53·0% were male. After adjusting for other glycemic measures (fasting glucose, 2-h glucose and/or HbA_1c where relevant) in addition to age, sex, ethnicity and smoking habit, the hazard ratios for incident diabetes and diabetes complications of retinopathy and nephropathy were highest for 2-h glucose levels, followed by HbA_1c and lastly by fasting glucose. However, all-cause mortality and CHD were significantly associated with HbA_1c concentrations only, and ischemic stroke and CVD events with 2-h glucose only. Circulatory complications showed a stronger association with HbA_1c.

CONCLUSION

Apart from neuropathy, HbA_1c showed stronger associations with outcomes compared to fasting glucose and provides a convenient alternative to an oGTT.

A Review on Glycosylated Hemoglobin in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is one of the most common reproductive endocrine disorders among women of reproductive age, with a variety of complications and consequences mostly due to hyperandrogenism and insulin resistance (IR). PCOS patients with IR are at risk for metabolic syndrome and diabetes mellitus (DM) along with its complications such as cardiovascular events. There are several methods for screening IR in patients with PCOS to predict DM and other complications. Fasting plasma glucose test, oral glucose tolerance test, and insulin and glycosylated hemoglobin (HbA1c) levels are some available screening tools for IR. The American Diabetes Association recommended HbA1c to screen for DM because HbA1c is not affected by day-to-day plasma glucose levels and reflects the plasma glucose status during 2-3 months before measurement. Some studies have evaluated the role of HbA1c as a screening method to predict DM in PCOS patients, however, there are still controversies in this matter. Also some studies reported that HbA1c has a correlation with complications of PCOS such as metabolic syndrome and cardiovascular events. We found that HbA1c could be a suitable screening test for IR in PCOS patients but more studies are recommended, omitting confounding factors that could affect IR in patients with PCOS, such as antihyperglycemic agents like metformin, or lifestyle modification, which can be effective in reducing IR in patients with PCOS.

High HbA1c is associated with higher risk of ischaemic stroke in Pakistani population without diabetes

CONTEXT

The role of glycated haemoglobin (HbA1c) in the prediction of ischaemic stroke in individuals without diabetes is underestimated.

AIMS

We performed a study to analyse the role of HbA1c in the risk prediction of ischaemic stroke in Pakistani population without diabetes. We further studied the difference between HbA1c values of individuals with diabetes and without diabetes with stroke.

SETTINGS AND DESIGN

Single centre, case-control.

MATERIALS AND METHODS

In phase I, a total of 233 patients without diabetes with ischaemic stroke and 245 as controls were enrolled. Association of HbA1c levels, lipid profiles and blood pressure recordings with ischaemic stroke was analysed. In phase II, comparison was done between diabetics and non-diabetics with stroke.

STATISTICAL ANALYSIS

Comparison of the mean variables was performed with Student's t-tests. Logistic regression analysis with ischaemic stroke as the dependent variable was performed for phase I.

RESULTS

In phase I, the ischaemic stroke group had significantly higher HbA1c levels (5.9±2.9% vs 5.5±1.6%) compared with controls (p<0.05). Triglyceride cholesterol, high-density lipoprotein cholesterol, systolic blood pressure, diastolic blood pressure and HbA1c were the significant determinants of stroke (p<0.05). In phase II, mean HbA1c values were significantly higher in the diabetes group (7.6±2.1 vs 6.1±2.3) (p<0.05) but other parameters were not statistically significantly different (p>0.05).

CONCLUSIONS

Higher HbA1c indicated a significantly increased risk for ischaemic stroke. An HbA1c value above 5.6% (prediabetic range) predicted future risk of stroke and efforts to maintain glucose level within the normal range (≤5.6%) in individuals with high cardiovascular risk are important.

Are There Clinical Implications of Racial Differences in HbA1c? A Difference, to Be a Difference, Must Make a Difference

Studies that have compared HbA1c levels by race have consistently demonstrated higher HbA1c levels in African Americans than in whites. These racial differences in HbA1c have not been explained by measured differences in glycemia, sociodemographic factors, clinical factors, access to care, or quality of care. Recently, a number of nonglycemic factors and several genetic polymorphisms that operate through nonglycemic mechanisms have been associated with HbA1c Their distributions across racial groups and their impact on hemoglobin glycation need to be systematically explored. Thus, on the basis of evidence for racial differences in HbA1c, current clinical guidelines from the American Diabetes Association state: "It is important to take…race/ethnicity…into consideration when using the A1C to diagnose diabetes." However, it is not clear from the guidelines how this recommendation might be actualized. So, the critical question is not whether racial differences in HbA1c exist between African Americans and whites; the important question is whether the observed differences in HbA1c level are clinically meaningful. Therefore, given the current controversy, we provide a Point-Counterpoint debate on this issue. In the preceding point narrative, Dr. Herman provides his argument that the failure to acknowledge that HbA1c might be a biased measure of average glycemia and an unwillingness to rigorously investigate this hypothesis will slow scientific progress and has the potential to do great harm. In the counterpoint narrative below, Dr. Selvin argues that there is no compelling evidence for racial differences in the validity of HbA1c as a measure of hyperglycemia and that race is a poor surrogate for differences in underlying causes of disease risk.-William T. CefaluEditor in Chief, Diabetes Care.

Effect of Diabetes and Glycemic Control on Ischemic Stroke Risk in AF Patients: ATRIA Study

BACKGROUND

Diagnosed diabetes mellitus (DM) is a consistently documented risk factor for ischemic stroke in patients with atrial fibrillation (AF).

OBJECTIVES

The purpose of this study was to assess the association between duration of diabetes and elevated hemoglobin A1c (HbA1c) with risk of stroke among diabetic patients with AF.

METHODS

We assessed this association in the ATRIA (Anticoagulation and Risk Factors in Atrial Fibrillation) California community-based cohort of AF patients (study years 1996 to 2003) where all events were clinician adjudicated. We used Cox proportional hazards regression to estimate the rate of ischemic stroke in diabetic patients according to time-varying measures of estimated duration of diabetes (≥3 years compared with <3 years) and HbA1c values (≥9.0% and 7.0% to 8.9% compared with <7.0%), focusing on periods where patients were not anticoagulated.

RESULTS

There were 2,101 diabetic patients included in the duration analysis: 40% with duration <3 years and 60% with duration ≥3 years at baseline. Among 1,933 diabetic patients included in the HbA1c analysis, 46% had HbA1c <7.0%, 36% between 7.0% and 8.9%, and 19% ≥9.0% at baseline. Duration of diabetes ≥3 years was associated with an increased rate of ischemic stroke compared with duration <3 years (adjusted hazard ratio [HR]: 1.74, 95% confidence interval [CI]: 1.10 to 2.76). The increased stroke rate was observed in older (age ≥75 years) and younger (age <75 years) individuals. Neither poor glycemic control (HbA1c ≥9.0%, adjusted HR: 1.04, 95% CI: 0.57 to 1.92) nor moderately increased HbA1c (7.0% to 8.9%, adjusted HR: 1.21, 95% CI: 0.77 to 1.91) were significantly associated with an increased rate of ischemic stroke compared with patients who had HbA1c <7.0%.

CONCLUSIONS

Duration of diabetes is a more important predictor of ischemic stroke than glycemic control in patients who have diabetes and AF.

Relationship between glycated hemoglobin A1c and cognitive function in nondemented elderly patients with type 2 diabetes

Elderly patients with type 2 diabetes are at a greater risk for cognitive decline. The purpose of this study was to assess the relationship between the degree of hyperglycemia and cognitive status in nondemented, elderly diabetics. Between Jan 2013 and Dec 2014, 1174 geriatric patients with type 2 diabetes were enrolled in the study (579 males; age ≥ 60 years; from Fuzhou, Fujian, China). Cognitive function was measured with the Mini Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). A statistically significant, age-adjusted association was observed between the A1C levels and the scores on two cognitive tests (MMSE and MoCA). Specifically, a 1% higher A1C value was associated with a 0.21-point lower MMSE score (95% CI; compare -0.11 to -0.28; P < 0.0001), as well as a 0.11-point lower MoCA score (95% CI; compare -0.10 to -0.38; P < 0.0001). Higher A1C levels were not significantly associated with lower MMSE and MoCA test scores after adjusting for all variables. No significant correlation was found between the two variables in patients older than 80 years of age (n = 215; OR = 1.019; 95% CI = 0.968 - 1.099; p = 0.251). Evidence strongly suggests that chronic hyperglycemia is associated with a decline in cognitive function in nondemented elderly patients with type 2 diabetes. When cognitive assessments are made, comprehensive factors such as advanced age, education level, duration of diabetes, hypertension and other vascular risks should be taken into account. For older geriatric patients (age ≥ 80 years), there is no significant correlation between A1c levels and cognitive function.

Association between hemoglobin A₁C levels and clinical outcome in ischemic stroke patients with or without diabetes

Individuals with diabetes are at a higher risk of suffering stroke, but whether chronic hyperglycemia affects clinical outcomes after stroke is unclear. We examined whether chronic hyperglycemia, measured in terms of hemoglobin A1C (HbA₁C) levels, influences clinical outcomes after acute ischemic stroke. We prospectively and consecutively included patients admitted within 7 days of ischemic stroke onset. Demographic and clinical information and outcomes were analyzed separately for patients with or without diabetes in order to identify associations with HbA₁C tercile. A total of 1351 patients without diabetes and 526 with diabetes were included. The risk of mortality and poor outcome showed a tendency to increase with increasing HbA₁C tercile in both groups. Rates of mortality and poor outcome were significantly higher in the third tercile than in the first tercile. In contrast, rates of mortality and poor outcome in the second tercile were not significantly different from those in the first tercile. The adjusted odds ratios of poor outcome and mortality increased with increasing tercile of HbA₁C both in patients with diabetes and in patients without diabetes, and these relationships were independent of other confounders. Kaplan-Meier estimates of cumulative mortality also increased with increasing HbA₁C in both groups of patients (with diabetes, p=0.034; without diabetes, p=0.025). Our results suggest that elevated HbA₁C is associated with risk of poor outcome and mortality in ischemic stroke patients with or without diabetes.

Visit-to-visit variability of fasting plasma glucose as predictor of ischemic stroke: competing risk analysis in a national cohort of Taiwan Diabetes Study

BACKGROUND

Glycemic variation as an independent predictor of ischemic stroke in type 2 diabetic patients remains unclear. This study examined visit-to-visit variations in fasting plasma glucose (FPG), as represented by the coefficient of variation (CV), for predicting ischemic stroke independently, regardless of glycated hemoglobin (HbA1c) and other conventional risk factors in such patients.

METHODS

Type 2 diabetic patients enrolled in the National Diabetes Care Management Program, ≥30 years old and free of ischemic stroke (n = 28,354) in 2002 to 2004 were included, and related factors were analyzed with extended Cox proportional hazards regression models of competing risk data on stroke incidence.

RESULTS

After an average 7.5 years of follow-up, there were 2,250 incident cases of ischemic stroke, giving a crude incidence rate of 10.56/1,000 person-years (11.64 for men, 9.63 for women). After multivariate adjustment, hazard ratios for the second, third and fourth versus first FPG-CV quartile were 1.11 (0.98, 1.25), 1.22 (1.08, 1.38) and 1.27 (1.12, 1.43), respectively, without considering HbA1c, and 1.09 (0.96, 1.23), 1.16 (1.03, 1.31) and 1.17 (1.03, 1.32), respectively, after considering HbA1c.

CONCLUSIONS

Besides HbA1c, FPG-CV was a potent predictor of ischemic stroke in type 2 diabetic patients, suggesting that different therapeutic strategies now in use be rated for their potential to (1) minimize glucose fluctuations and (2) reduce HbA1c level in type 2 diabetic patients to prevent ischemic stroke.

Glycated hemoglobin as a marker of subclinical atherosclerosis and cardiac remodeling among non-diabetic adults from the general population

BACKGROUND

Elevated glycated hemoglobin (HbA1c) is associated with increased risk of cardiovascular disease (CVD) and mortality but little is known about potential mechanisms underlying the reported associations.

METHODS

We used data from 1798 non-diabetic participants from the population-based cohort Study of Health in Pomerania (SHIP) to investigate cross-sectional and longitudinal associations of HbA1c with subclinical atherosclerosis (common carotid artery intima-media thickness [CCA-IMT]), cardiac structure (left ventricular mass [LVM]), and cardiac function (fractional shortening).

RESULTS

Cross-sectional analyses revealed a positive association between HbA1c and mean CCA-IMT with a 0.02 mm (95% confidence interval: 0.01-0.04) increase in CCA-IMT per 1% increase in HbA1c, and a similar positive trend across HbA1c quartiles (overall p-value <0.01). We also observed a graded association between HbA1c and high CCA-IMT (>75th percentile) with an odds ratio of 1.42 (95% CI: 1.11-1.81) per 1% increase in HbA1c. Longitudinal analyses showed no consistent associations of baseline HbA1c with mean follow-up CCA-IMT. There were no consistent associations of HbA1c with cardiac remodeling in cross-sectional and longitudinal analyses, respectively.

CONCLUSIONS

The association between HbA1c and CCA-IMT in non-diabetic adults may be a crucial link between high-normal HbA1c levels and an increased risk of CVD and mortality.

Protein-phenolic interactions and inhibition of glycation - combining a systematic review and experimental models for enhanced physiological relevance

BACKGROUND

while antiglycative capacity has been attributed to (poly)phenols, the exact mechanism of action remains unclear. Studies so far are often relying on supra-physiological concentrations and use of non-bioavailable compounds.

METHODS

to inform the design of a physiologically relevant in vitro study, we carried out a systematic literature review of dietary interventions reporting plasma concentrations of polyphenol metabolites. Bovine Serum Albumin (BSA) was pre-treated prior to in vitro glycation: either no treatment (native), pre-oxidised (incubated with 10 nM H2O2, for 8 hours) or incubated with a mixture of phenolic acids at physiologically relevant concentrations, for 8 hours). In vitro glycation was carried out in the presence of (i) glucose only (0, 5 or 10 mM), (ii) glucose (0, 5 or 10 mM) plus H2O2 (10 nM), or (iii) glucose (0, 5 or 10 mM) plus phenolic acids (10-160 nM). Fructosamine was measured using the nitro blue tetrazolium method.

RESULTS

following (high) dietary polyphenol intake, 3-hydroxyphenylacetic acid is the most abundant phenolic acid in peripheral blood (up to 338 μM) with concentrations of other phenolic acids ranging from 13 nM to 200 μM. The presence of six phenolic acids with BSA during in vitro glycation did not lower fructosamine formation. However, when BSA was pre-incubated with phenolic acids, significantly lower concentration of fructosamine was detected under glycoxidative conditions (glucose 5 or 10 mM plus H2O2 10 nM) (p < 0.001 vs. native BSA).

CONCLUSION

protein pre-treatment, either with oxidants or phenolic acids, is an important regulator of subsequent glycation in a physiologically relevant system. High quality in vitro studies under conditions closer to physiology are feasible and should be employed more frequently.

Oxidative stress, protein glycation and nutrition--interactions relevant to health and disease throughout the lifecycle

Protein glycation has been studied for over a century now and plays an important role in disease pathogenesis throughout the lifecycle. Strongly related to diabetic complications, glycation of Hb has become the gold standard method for diabetes diagnosis and monitoring. It is however attracting attention in normoglycaemia as well lately. Longitudinal studies increasingly suggest a positive relationship between glycation and the risk of chronic diseases in normoglycaemic individuals, but the mechanisms behind this association remain unclear. The interaction between glycation and oxidative stress may be particularly relevant in the normoglycaemic context, as suggested by recent epidemiological and in vitro evidence. In that context nutritional and lifestyle factors with an influence on redox status, such as smoking, fruit and vegetable and antioxidants consumption, may have the capacity to promote or inhibit glycation. However, experimental data from controlled trials are lacking the quality and rigour needed to reach firm conclusions. In the present review, we discuss the importance of glycation for health through the lifecycle and focus on the importance of oxidative stress as a driver for glycation. The importance of nutrition to modulate glycation is discussed, based on the evidence available and recommendations towards higher quality future research are made.

Evaluation of HbA1c criteria for diagnosis of diabetes mellitus: a retrospective study of 12 785 type 2 Saudi male patients

Recently, American Diabetic Association has recommended glycated hemoglobin (HbA1c ≥6.5%) as an alternate to fasting plasma glucose (FPG ≥7.0 mmol/L) for diagnosis of diabetes. However, studies from different groups showed inconsistent results with the use of HbA1c criteria. We examined the validity of HbA1c cut-point of 6.5% for diagnosis of diabetes. A total of 12 785 male diabetic patients (FGP ≥7.0 mmol/L), aged 56.27 ± 13.32 years were included. The average values of FPG and HbA1c of all the 12 785 patients were 10.127 ± 0.026 mmol/L and 8.729 ± 0.013%, respectively. Sub-grouping of patients into different age categories showed significantly high levels of FPG (10.934 ± 0.123 mmol/L) in the youngest group (age, ≥20-35 years) as compared to FPG (ranged from 10.021 ± 0.052 to 10.190 ± 0.050 mmol/L) in patients with other age categories. The level of HbA1c was highest in the youngest group (8.809 ± 0.056%) and lowest in the oldest group (8.653 ± 0.082%). There was a significant correlation between FPG and HbA1c (R = 0.571, p < 0.001). There were 484 patients below the diagnostic threshold (HbA1c <6.5%), resulting in 3.78% false negative predictions. Majority of the false negative patients were in the age group of 40-75 years and had borderline FPG (7.0-8.0 mmol/L) and HbA1c (6.0-6.5%). These findings suggest that Saudi individuals with HbA1c between 6.0% and 6.5% may be considered as "probable diabetic" and their status should be verified by combined FPG and HbA1c criteria.