Prevalence of Abnormal Glucose Metabolism and Insulin Resistance Among Subtypes of Ischemic Stroke in Japanese Patients

Risk of Carotid Atherosclerosis in Subjects with Prediabetes Overlapping Metabolic Syndrome

Background: While the number of individuals with prediabetes and metabolic syndrome (MetS) is increasing, only a few studies have reported differences in cardiovascular risk according to the presence or absence of MetS in individuals with prediabetes. Here, we examined differences in carotid intima-media thickness (CIMT) and carotid plaques in individuals with prediabetes with or without MetS among subjects who visited a single center in Seoul (Huh Diabetes Center). Methods: A total of 328 participants aged ≥20 years, including the group with normoglycemia, were enrolled in the analysis, of which 273 had prediabetes. Individuals with prediabetes were defined as those who met one or more of the following two criteria: fasting plasma glucose of 100-125 mg/dL and/or HbA1c level of 5.7%-6.4%. Carotid atherosclerosis was determined by mean and maximal CIMT and by the presence of carotid plaques. Results: Eighty-nine subjects (32.6% of prediabetes group) were categorized as having MetS. Those with MetS had significantly higher mean CIMT and maximal CIMT than those without (P < 0.05). Moreover, the group with MetS had a significantly higher prevalence of carotid plaques than the group without MetS [odds ratio (OR): 2.45, 95% confidence interval (CI): 1.43-4.19; P = 0.001]. After adjusting for age, sex, body mass index, and low-density lipoprotein cholesterol, individuals with MetS still had greater mean and maximal CIMT than individuals without MetS (P < 0.05), and the presence of MetS was significantly associated with a higher risk of carotid plaques (OR: 2.55, 95% CI: 1.06-6.15; P = 0.037). Conclusion: These results suggest that MetS is independently associated with increased CIMT and the presence of carotid plaques in prediabetes. Our study indicates that the risk of cardiovascular disease (CVD) is high in prediabetic individuals with MetS, and that more attention is needed on the risk of CVD in these individuals.

The Influence of Different Types of Diabetes on Vascular Complications

The final outcome of diabetes is chronic complications, of which vascular complications are the most serious, which is the main cause of death for diabetic patients and the direct cause of the increase in the cost of diabetes. Type 1 and type 2 diabetes are the main types of diabetes, and their pathogenesis is completely different. Type 1 diabetes is caused by genetics and immunity to destroy a large number of β cells, and insulin secretion is absolutely insufficient, which is more prone to microvascular complications. Type 2 diabetes is dominated by insulin resistance, leading to atherosclerosis, which is more likely to progress to macrovascular complications. This article explores the pathogenesis of two types of diabetes, analyzes the pathogenesis of different vascular complications, and tries to explain the different trends in the progression of different types of diabetes to vascular complications, in order to better prevent diabetes and its vascular complications.

Omentin-1: Protective impact on ischemic stroke via ameliorating atherosclerosis

Omentin-1, a newly identified adipokine, has recently been revealed as a novel biomarker for ischemic stroke (IS). Low circulating omentin-1 levels could indicate a high risk of IS, and elevated omentin-1 levels exert a favorable impact on cerebral ischemia. Furthermore, omentin-1 has anti-atherosclerotic, anti-inflammatory, and cardiovascular protective capabilities through the intracellular Akt/AMP-activated protein kinase (AMPK)/ nuclear factor-κB (NF-κB) and certain protein kinase (ERK, JNK, and p38) signaling pathways. Omentin-1 also alleviates endothelial cell dysfunction, improves revascularization via the Akt-endothelial nitric-oxide synthase (eNOS) regulatory axis, promotes endothelium-dependent vasodilation through endothelium-derived NO in an eNOS fashion, and inhibits VSMC proliferation by means of AMPK/ERK signaling pathways, VSMC migration via inactivation of the NADPH oxidase (NOX)/ROS/p38/HSP27 pathways and artery calcification via the PI3K-Akt pathway. These findings indicate that omentin-1 may be a negative mediator of IS. Pharmacologically, several lines of clinical evidence indicate that metformin and statins could elevate omentin-1 levels, although the specific mechanism has not been precisely delineated until now. This study is the first to summarize the comprehensive mechanisms between omentin-1 and atherosclerosis and to review the shielding effect of omentin-1 on IS. We shed light on omentin-1 as a novel therapeutic target for combating IS.

Metabolic endotoxemia promotes neuroinflammation after focal cerebral ischemia

Lipopolysaccharide (LPS) is a major component of the outer membrane of Gram-negative bacteria and a potent inflammatory stimulus for the innate immune response via toll-like receptor (TLR) 4 activation. Type 2 diabetes is associated with changes in gut microbiota and impaired intestinal barrier functions, leading to translocation of microbiota-derived LPS into the circulatory system, a condition referred to as metabolic endotoxemia. We investigated the effects of metabolic endotoxemia after experimental stroke with transient middle cerebral artery occlusion (MCAO) in a murine model of type 2 diabetes (db/db) and phenotypically normal littermates (db/+). Compared to db/+ mice, db/db mice exhibited an altered gut microbial composition, increased intestinal permeability, and higher plasma LPS levels. In addition, db/db mice presented increased infarct volumes and higher expression levels of LPS, TLR4, and inflammatory cytokines in the ischemic brain, as well as more severe neurological impairments and reduced survival rates after MCAO. Oral administration of a non-absorbable antibiotic modulated the gut microbiota and improved metabolic endotoxemia and stroke outcomes in db/db mice; these effects were associated with reduction of LPS levels and neuroinflammation in the ischemic brain. These data suggest that targeting metabolic endotoxemia may be a novel potential therapeutic strategy to improve stroke outcomes.

Interleukin-13 ameliorates postischemic hepatic gluconeogenesis and hyperglycemia in rat model of stroke

Hyperglycemia is a well-known indicator of stroke prognosis, and one-third of nondiabetic patients develop postischemic hyperglycemia during the acute phase of stroke; this is related to relatively poor prognosis, high mortality, and impaired neurological recovery. Interleukin-13 (IL-13), a member of the Th2 cytokine family, is involved in both the regulation of immune response and glucose metabolism. Thus, we investigated the mechanism of postischemic hyperglycemia and the role of IL-13 by using a permanent middle cerebral artery occlusion (MCAO) rat model. Our results indicated that postischemic hyperglycemia was accompanied with hyperinsulinemia and increased HOMA-IR, elevated hepatic gluconeogenesis, and suppressed insulin signaling. A shift towards inflammatory response was evident with results of elevated proinflammatory cytokines and increased expression of negative regulatory proteins, suggesting an ongoing vicious cycle of inflammatory-induced insulin-resistant hyperglycemia. IL-13 treatment counteracted the proinflammatory states and abolished the vicious cycle through enhancing STAT6 and STAT3, which mediated the immune and metabolic pathways respectively; these effects resolved the formerly described pathological changes of postischemic hyperglycemia and reduced infarction size in the MCAO rats. Our findings demonstrated the importance of Th1-Th2 balance in the peripheral glucose metabolism affected by acute ischemic stroke, which provides a new perspective for the prevention and control of postischemic hyperglycemia.

Glycine Improves Ischemic Stroke Through miR-19a-3p/AMPK/GSK-3β/HO-1 Pathway

Purpose

To explore the molecular mechanism of glycine in improving ischemic stroke.

Patients and Methods

The serum samples of patients with ischemic stroke and healthy people were compared. The ischemic stroke model of PC12 cells was established by oxygen-glucose deprivation (OGD). qPCR quantified miR-19a-3p and AMPK mRNA, and protein expression was detected by Western blot. MTT was used to detect cell activity. Flow cytometry was used to detect cells. Glucose metabolism kit was used to detect glucose intake and formation amount of lactic acid.

Results

Compared with the control group, OGD group (OGDG) showed lower cell activity and increased cell apoptosis. TNF-α, IL-1βI, L-6, Caspase 3, Caspase 9 and Bax were up-regulated, and Glut1, HK2, LDHA, PDK1, PKM2 and Bcl2 were down-regulated. At the same time, glucose intake, formation amount of lactic acid and cell apoptosis rate were reduced, and AMPK/GSK-3β/HO-1 pathway activity was down-regulated. Glycine could counteract the above phenomena in OGDG. miR-19a-3p and AMPK decreased and increased, respectively, during glycine therapy. AMPK was the target gene of miR-19a-3p. Rescue experiments demonstrated that glycine improved cell apoptosis, inflammatory response and glucose metabolism disorder of ischemic stroke through miR-19a-3p/AMPK/GSK-3β/HO-1 pathway.

Conclusion

Glycine improves ischemic stroke through miR-19a-3p/AMPK/GSK-3β/HO-1 pathway.

Prediction of Persistent Impaired Glucose Tolerance in Patients with Minor Ischemic Stroke or Transient Ischemic Attack

BACKGROUND

Impaired glucose tolerance (IGT) in patients with ischemic stroke can return to normal, reflecting an acute stress response, or persist. Persistent IGT is associated with an increased risk of recurrent stroke, other cardiovascular diseases and unfavorable outcome after stroke. We aim to validate our previously developed model to identify patients at risk of persistent IGT in an independent data set, and, if necessary, update the model.

METHODS

The validation data set consisted of 239 nondiabetic patients with a minor ischemic stroke or TIA and IGT in the acute phase (2-hour post-load glucose levels between 7.8 and 11.0 mmol/l). The outcome was persistent versus normalized IGT, based on repeated oral glucose tolerance test after a median of 46 days. The discriminative ability of the original model was assessed with the area under the ROC curve (AUC). The updated model was internally validated with bootstrap resampling and cross-validated in the development population of the original model.

RESULTS

One-hundred eighteen of 239 (49%) patients had persistent IGT. The original model, with the predictors age, current smoking, statin use, triglyceride, hypertension, history of cardiovascular diseases, body mass index (BMI), fasting plasma glucose performed poorly (AUC .60). The newly developed model included only BMI, hypertension, statin use, atrial fibrillation, 2-hour post-load glucose levels, HbA1c, large artery atherosclerosis, and predicted persistent IGT more accurately (internally validated AUC 0.66, externally validated AUC .71).

CONCLUSIONS

This prediction model with simple clinical variables can be used to predict persistent IGT in patients with IGT directly after minor stroke or TIA, and may be useful to optimize secondary prevention by early identification of patients with disturbed glucose metabolism.

Health risks and interventions in prediabetes: A review

Prediabetes is a condition which appears prior to the development of diabetes in which blood glucose is abnormally high but do not reach the diagnostic threshold of type 2 diabetes mellitus. It is characterized by a cluster of metabolic abnormalities viz. dysglycemia, dyslipidemia, hypertension, physical inactivity, obesity, insulin resistance, procoagulant state, endothelial dysfunction, oxidative stress and inflammation, placing prediabetic subjects to an increased risk for diabetes and its complications. Recent studies demonstrate that complications of diabetes i.e. microvascular and macrovascular complications may manifest in some prediabetic subjects. This article reviews prediabetes-related risk factors and health issues. In addition, this article also highlights the interventions to prevent the development of diabetes in prediabetic subjects.

Effect of pioglitazone in acute ischemic stroke patients with diabetes mellitus: a nested case-control study

Background

Pioglitazone is an oral antidiabetic drug with multiple pleiotropic actions. Recent clinical trials have demonstrated that treatment with pioglitazone reduces cardiovascular risk in patients who have had an ischemic stroke. We examined the secondary preventive effects of pioglitazone in acute ischemic stroke patients with diabetes mellitus (DM) based on nationwide real-world data.

Methods

A nested case–control study was conducted with data from the National Health Insurance Service-National Sample Cohort in Korea. Study subjects were diabetic patients admitted for acute ischemic stroke (ICD-10 code; I63) between 2002 and 2013. Cases were defined as patients who suffered from composites of recurrent stroke (I60–63), myocardial infarction (I21), or all-cause mortality after ischemic stroke. Controls were selected by incidence density sampling. Three controls were matched to each case for sex, age, treatment with insulin, and oral antidiabetic medications, with the exception of pioglitazone. Medication history after ischemic stroke was obtained by accessing the prescription records. In the matched dataset, conditional logistic regression analysis was performed with adjustments for hypertension, atrial fibrillation, prior myocardial infarction, and treatment with oral antithrombotics and statins.

Results

From the patients with acute ischemic stroke and DM, 1150 cases with primary outcomes were matched to 3450 controls. In the matched analysis, treatment with pioglitazone was significantly associated with a lower cardiovascular risk (adjusted OR [95% CI], 0.43 [0.23–0.83]).

Conclusions

In this nested case–control study using real-world data, treatment with pioglitazone exhibited significant cardiovascular preventive effect in diabetic patients with acute ischemic 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.

Treating prediabetes: why and how should we do it?

Prediabetes is the subclinical impairment in fasting plasma glucose, impaired glucose tolerance or both. The degree of impairment is between euglycemia and the hyperglycemia of type 2 diabetes (T2DM). Prediabetes is not considered benign, because it is a risk factor for T2DM but is also associated with micro and macrovascular complications. Lifestyle interventions including diet and exercise are first-line treatments. Medications can also play a role, as randomized controlled trials of biguanides (metformin) alpha-glucosidase inhibitors (Acarbose), inhibitors of pancreatic lipase (Orlistat), PPAR-gamma agonists (Rosiglitazone, Pioglitazone), meglitinides (Nateglinide) and GLP-1 receptor agonists (Liraglutide) have all shown benefits. Bariatric surgery is another efficacious means of preventing T2DM in patients with prediabetes and obesity. Prediabetes in its various guises is a risk factor for the future development T2DM and diabetic complications. Importantly the prediabetic state is amenable to interventions that prevent/delay transition to overt T2DM. Knowledge gaps exist regarding how best to make prognostication highly sensitive and specific as to which patient will develop T2DM. Moreover, understanding of phenotype specific pathophysiology may add value to funding appropriate interventions for patients with prediabetes. Management of patients with prediabetes should be individualized based on the algorithms that predict phenotype specific risk and allow for the use of phenotype tailored interventions.

Impact of prediabetes on poststroke depression in Chinese patients with acute ischemic stroke

OBJECTIVE

It is unknown whether prediabetes is a predictor of poststroke depression (PSD). We aimed to explore the relationship between prediabetes and PSD in Chinese patients with acute ischemic stroke.

METHODS

This is a prospective cohort study, and a total of 358 patients with acute ischemic stroke were recruited and enrolled. Patients were divided into 3 groups: normal glucose group (NGT, n = 96), prediabetes group (preDM, n = 134, impaired fasting glucose (IFG), and/or impaired glucose tolerance (IGT) and/or HbA1c (A1c) 5.7%-6.4%), and the diabetes mellitus group (DM, n = 128). At 1 month after stroke, patients with a Hamilton Depression Scale score of ≥8 were diagnosed as PSD.

RESULTS

In post hoc comparisons, the risk of PSD in patients with diabetes and prediabetes was higher than patients with NGT (37.5% vs 31.3% vs 14.6%, P = .001). Compared with NGT, the incidence rate of PSD in patients with prediabetes with HbA1c 5.7% to 6.4% and patients with prediabetes with IFG/IGT + HbA1c 5.7% to 6.4% was higher (35.3% vs 14.6%, 38.0% vs 14.6%; P = .006; P = .003, respectively). In logistic regression, prediabetes with HbA1c 5.7% to 6.4% and prediabetes with IFG/IGT + HbA1c 5.7% to 6.4% were a significant independent predictor of PSD after adjusting for potential confounding factors, with odd ratios of 1.731 and 1.978, respectively.

CONCLUSIONS

Our study showed that prediabetes was associated with PSD and may predict its development at 1 month poststroke. In prediabetes subgroups, patients with HbA1c 5.7% to 6.4% were more likely to develop PSD compared to NGT and IFG/IGT groups.

Homeostasis model assessment of insulin resistance in relation to the poor functional outcomes in nondiabetic patients with ischemic stroke

Whether insulin resistance (IR) predicts worse functional outcome in ischemic stroke is still a matter of debate. The aim of the present study is to determine the association between IR and risk of poor outcome in 173 Chinese nondiabetic patients with acute ischemic stroke. This is a prospective, population-based cohort study. Insulin sensitivity, expressed by the homeostasis model assessment (HOMA) of insulin sensitivity (HOMA index = (fasting insulin × fasting glucose)/22.5). IR was defined by HOMA-IR index in the top quartile (Q4). Functional impairment was evaluated at discharge using the modified Rankin scale (mRS). The median (interquartile range) HOMA-IR was 2.14 (1.17–2.83), and Q4 was at least 2.83. There was a significantly positive correlation between HOMA-IR and National Institutes of Health Stroke Scale (r = 0.408; P<0.001). In multivariate analyses, patients in IR group were associated with a higher risk of poor functional outcome (odds ratio (OR) = 3.23; 95% confidence interval (CI) = 1.75–5.08; P=0.001). In multivariate models comparing the third and fourth quartiles against the first quartile of the HOMA-IR, levels of HOMA-IR were associated with poor outcome, and the adjusted risk of poor outcome increased by 207% (OR = 3.05 (95% CI 1.70–4.89), P=0.006) and 429% (5.29 (3.05–9.80), P<0.001). In a receiver operating characteristic curve (ROC) analysis of poor outcome, the area under the curve (AUC) increased from 0.80 to 0.84 (95% CI: 0.79–0.88) by adding HOMA-IR to clinical examination variables (P=0.02). High HOMA-IR index is associated with a poor functional outcome in nondiabetic patients with acute ischemic stroke.

Prediabetes and Cardiovascular Disease: Pathophysiology and Interventions for Prevention and Risk Reduction

Prediabetes is a state characterized by impaired fasting glucose or impaired glucose tolerance. This review discusses the pathophysiology and macrovascular complications of prediabetes. The pathophysiologic defects underlying prediabetes include insulin resistance, alpha- and beta-cell dysfunction, increased lipolysis, inflammation, and suboptimal incretin effect. Recent studies have revealed that the long-term complications of diabetes manifest in some people with prediabetes; these complications include microvascular and macrovascular disorders. Finally, we present an overview of randomized control trials aimed at preventing progression from prediabetes to type 2 diabetes and discuss their implications for macrovascular risk reduction.

Insulin resistance in ischemic stroke

Insulin resistance often refers to a pathological condition in which cells fail to respond to the normal actions of insulin. Increasing literature has noted a critical role of insulin resistance in the pathogenesis of ischemic stroke. Insulin resistance plays an important role in the pathogenesis of ischemic stroke via enhancing advanced changes of atherosclerosis. A variety of literature indicates that insulin resistance enhances platelet adhesion, activation and aggregation which are conducive to the occurrence of ischemic stroke. Insulin resistance also induces hemodynamic disturbances and contributes to the onset of ischemic stroke. In addition, insulin resistance may augment the role of the modifiable risk factors in ischemic stroke and induce the occurrence of ischemic stroke. Preclinical and clinical studies have supported that improving insulin resistance may be an effective measure to prevent or delay ischemic stroke.

Role of prediabetes in stroke

Stroke is one of the leading causes of death and probably the greatest cause of adult disability worldwide. Diabetes mellitus (DM) is a state of accelerated aging of blood vessels. Patients with diabetes have increased risk of stroke. Hyperglycemia represents a risk factor for poor outcome following stroke, and probably is just a marker of poor outcome rather than a cause. Lowering of blood glucose levels has not been shown to improve prognosis. Also, prevention of stroke risk among patients with DM is not improved with therapy for reduction of glucose levels. On the other hand, prediabetes, a metabolic state between normal glucose metabolism and diabetes, is a risk factor for the development of DM type 2 and subsequently for stroke. Several methods are known to identify prediabetes patients, including fasting plasma glucose levels, 2-hour post load glucose levels, and glycosylated hemoglobin levels. In this text, we tried to summarize known data about diagnosis, epidemiology, risk factors, pathophysiology, and prevention of prediabetes in relation to DM and stroke.

Decreased Insulin Sensitivity and Impaired Fibrinolytic Activity in Type 2 Diabetes Patients and Nondiabetics with Ischemic Stroke

We analyzed (a) insulin sensitivity (IS), (b) plasma insulin (PI), and (c) plasminogen activator inhibitor-1 (PAI-1) in type 2 diabetes (T2D) patients with (group A) and without (group B) atherothrombotic ischemic stroke (ATIS), nondiabetics with ATIS (group C), and healthy controls (group D). IS was determined by minimal model (Si). Si was lower in A versus B (1.18 ± 0.67 versus 2.82 ± 0.61 min-1/mU/L × 104; P < 0.001) and in C versus D (3.18 ± 0.93 versus 6.13 ± 1.69 min-1/mU/L × 104; P < 0.001). PI and PAI-1 were higher in A versus B (PI: 19.61 ± 4.08 versus 14.91 ± 1.66 mU/L; P < 0.001, PAI-1: 7.75 ± 1.04 versus 4.57 ± 0.72 mU/L; P < 0.001) and in C versus D (PI: 15.14 ± 2.20 versus 7.58 ± 2.05 mU/L; P < 0.001, PAI-1: 4.78 ± 0.98 versus 3.49 ± 1.04 mU/L; P < 0.001). Si correlated with PAI-1 in T2D patients and nondiabetics, albeit stronger in T2D. Binary logistic regression identified insulin, PAI-1, and Si as independent predictors for ATIS in T2D patients and nondiabetics. The results imply that insulin resistance and fasting hyperinsulinemia might exert their atherogenic impact through the impaired fibrinolysis.

The role of HbA1c determination in detecting unknown glucose disturbances in ischemic stroke

Objectives

To evaluate the usefulness of hemoglobin A1c (HbA1c) determinations during the acute ischemic stroke (IS) to identify undiagnosed glucose disturbances in a prospective series of patients with first-ever IS.

Methods

Retrospective analysis of a prospective series of first-ever IS patients. Patients with previous diagnosis of diabetes mellitus (DM) were excluded from the study. Patients were classified as non-DM (HbA1c<5.7% and no previous evidence of 2 or more fasting blood glucose> = 126 mg/dL), prediabetes (HbA1c from 5.7% to 6.4%), and new suspected DM (HbA1c> = 6.5% independently of current blood glucose). Medical charts from hospital discharge to July 2014 of all suspected DM patients were reviewed to confirm the DM diagnosis.

Results

The initial cohort included 1283 patients, of which 393 were excluded because of previous DM diagnosis and 136 because HbA1c during acute stroke phase was not available. No demographic differences were observed between patients with and without HbA1c determinations. The final cohort was composed of 754 patients with first-ever IS and unknown DM history. HbA1c determination suggested new DM in 87 cases (11.5%) and detected 273 patients with prediabetes (36.2%). New DM cases were identified in all etiological stroke subtypes. After discharge, DM diagnosis was confirmed in 80.2% of patients with available follow-up.

Conclusions

HbA1c determination detected both undiagnosed DM and prediabetes in IS patients without taking into account the blood glucose values during admission, and independently of etiological stroke subtype. HbA1c determination should be included in the systematic screening of all IS patients.

Guidelines for the primary prevention of stroke: a statement for healthcare professionals from the American Heart Association/American Stroke Association

The aim of this updated statement is to provide comprehensive and timely evidence-based recommendations on the prevention of stroke among individuals who have not previously experienced a stroke or transient ischemic attack. Evidence-based recommendations are included for the control of risk factors, interventional approaches to atherosclerotic disease of the cervicocephalic circulation, and antithrombotic treatments for preventing thrombotic and thromboembolic stroke. Further recommendations are provided for genetic and pharmacogenetic testing and for the prevention of stroke in a variety of other specific circumstances, including sickle cell disease and patent foramen ovale.

Glucose and lipid assessment in patients with acute stroke

Background

Stroke is a major health issue in Nigeria and it is also a common cause of emergency admissions. Stroke often results in increased morbidity, mortality and reduced quality of life in people thus affected. The risk factors for stroke include metabolic abnormalities such as dyslipidaemia and diabetes mellitus (DM). The stress of an acute stroke may present with hyperglycaemia and in persons without a prior history of DM, may be a pointer to stress hyperglycaemia or undiagnosed DM.

Methodology

This was a cross sectional study carried out over a period of one year in a teaching hospital in Lagos, Nigeria. Patients with acute stroke admitted to the hospital within three days of the episode of stroke and who met other inclusion criteria for the Study were consecutively recruited. Clinically relevant data was documented and biochemical assessments were carried out within three days of hospitalization. Tests for lipid profile, glycosylated haemoglobin(HbA1c), and blood glucose at presentation were carried out. The presence of past history of DM, undiagnosed DM, stress hyperglycaemia and abnormal lipid profile were noted. Students t test and Chi square were the statistical tests employed.

Results

A total of 137 persons with stroke were recruited of which 107 (76%) met the defining criteria for ischaemic stroke. The mean age and age range of the Study subjects were 62.2 (11.7) and 26–89 years respectively. The Study subjects were classified according to their glycaemic status into the following categories viz; stress hyperglycaemia, euglycaemia, DM and previously undiagnosed DM. Stress hyperglycaemia occurred commonly in the fifth decade of life and its incidence was comparable between those with cerebral and haemorrhagic stroke. The commonly occurring lipid abnormalities were elevated LDL-C and low HDL.

Conclusions

The detection of abnormal metabolic milieu is a window of opportunity for aggressive management in persons with stroke as this will improve outcome. Routine screening for hyperglycaemia in persons with stroke using glycosylated haemoglobin tests and blood glucose may uncover previously undiagnosed DM.

Prediabetes in patients with stroke or transient ischemic attack: prevalence, risk and clinical management

BACKGROUND

The prevalence of diabetes is emerging worldwide and is an important modifiable risk factor for stroke. People with prediabetes, an intermediate metabolic state between normal glucose metabolism and diabetes, have a tenfold increased risk of developing diabetes compared to those with a normal glucose metabolism. Prediabetes is comprised of impaired fasting glucose and/or impaired glucose tolerance and/or disturbed glycosylated hemoglobin levels. Prediabetes is highly prevalent in nondiabetic patients with transient ischemic attack (TIA) or ischemic stroke and nearly doubles their risk of stroke. This offers new options for secondary stroke prevention.

SUMMARY

Several detection methods exist for identifying (pre)diabetes, including fasting plasma glucose, 2-hour postload glucose and glycosylated hemoglobin levels. The concordance between these tests is not 100%, and they seem to be complementary. Screening for (pre)diabetes after stroke with fasting plasma glucose levels alone is insufficient, and 2-hour postload glucose and/or glycosylated hemoglobin levels should be determined as well. The prevalence of prediabetes in previously nondiabetic patients with a recent TIA or stroke ranges from 23 to 53%. This high prevalence in the acute phase after stroke can be transient or persistent, representing undiagnosed abnormal glucose metabolism. Impaired fasting glucose and impaired glucose tolerance have different pathophysiological mechanisms, including hepatic insulin resistance and muscle insulin resistance, respectively. Prediabetes seems to be a modest predictor for stroke, but doubles the risk for recurrent stroke. The relation between prediabetes after stroke and functional outcome is still unknown. However, it is most likely that prediabetes is a risk factor for a poor clinical outcome after stroke. There is a growing recognition that patients with prediabetes should be treated more aggressively. Both lifestyle and pharmacological interventions are possible treatment strategies. They are at least equally effective in preventing progression to diabetes. Lifestyle changes are difficult to maintain over a long period. The evidence of pharmacological interventions on stroke or other cardiovascular diseases is limited though and is still subject of several clinical trials.

CONCLUSIONS

As the prevalence of prediabetes is growing rapidly, prediabetes might become one of the most important modifiable therapeutic targets in both primary and secondary prevention.

Inordinate glucose variation poststroke is associated with poor neurological improvement in patients without history of diabetes

INTRODUCTION

Glucose variation is an important risk factor for the complications of diabetes mellitus. The plasma glucose level poststroke is in continuous fluctuation. However, whether the variation influences neurological improvement remains unknown.

AIMS

This observational study aimed to investigate the association of glucose variation with neurological improvement poststroke.

METHODS

We consecutively enrolled 216 ischemic stroke patients with no history of diabetes mellitus within 72 h of onset, with instant blood glucose <11.1 mmol/L at admission. The glucometabolic status was evaluated by an oral glucose tolerance test 1 day after admission and 14 days after stroke, respectively. The severity of neurological deficit was assessed with the National Institute of Health Stroke Scale (NIHSS).

RESULTS

Fourteen days after stroke, 31% patients were found to have impaired glucose tolerance and 30.6% were newly diagnosed diabetes mellitus by oral glucose tolerance test. A higher level of instant blood glucose at admission or fasting plasma glucose (FPG) at 1 day correlated with a less neurological improvement. The number of patients with no <20% decrease in NIHSS was significantly decreased in patient group with higher than 30% variation of either FPG or 2-h postprandial glucose. Similar correlation between glucose variation and neurological improvement was also found in 117 patients with 2-h postprandial glucose ≥7.8 mmol/L at 1 day.

CONCLUSIONS

Inordinate glucose variation correlated with less neurological improvement poststroke, giving the evidence that the fluctuation of glucose levels in stroke patients should be taken into consideration during glucose modulation.

Prevalence of metabolic syndrome in stroke patients: a prospective multicenter study in Japan

AIMS

The fact that Metabolic Syndrome (MetS) increases the risk of atherosclerosis has been epidemiologically studied and proven; however, a prospective study on the prevalence of MetS in stroke patients has never been conducted because of the difficulty in diagnosis under critical illness in the acute phase. Therefore, we conducted a prospective multicenter study to investigate the prevalence of MetS in stroke patients with modified diagnostic criteria for MetS.

METHODS

Stroke patients admitted in the seven participating Emergency and Critical Care Centers within the two years from April 2007 were registered in this study as a prospective multicenter study. Inclusion criteria were 50 to 89 year-old stroke patients who presented within three days from the onset of symptoms. A total of 992 subjects were classified according to the stroke type and the prevalence of MetS and the associated risk factors were investigated. The participants in a medical checkup without any history of a stroke were enrolled as the control group, and compared between the two groups.

RESULTS

The prevalence of MetS as well as hyperglycemia and dyslipidemia in the infarction group was significantly higher than that in the non-stroke group. While the hemorrhage group showed no significant difference in the prevalence of MetS, only hypertension was significantly high. According to a subtype analysis, there is a significant correlation between waist circumference increment of the stroke patients and the prevalence of the risk factors of hypertension, hyperglycemia and dyslipidemia.

CONCLUSIONS

Different risk factors are significantly related to the type of stroke.

Prevalence of prediabetes and newly diagnosed diabetes in patients with a transient ischemic attack or stroke

BACKGROUND

Patients with a transient ischemic attack (TIA) or stroke and prediabetes or newly diagnosed diabetes are at high risk of recurrent stroke or cardiovascular events. This underlines the importance of accurate screening for impaired glucose metabolism in clinical practice. Fasting plasma glucose levels are currently the most commonly measured glycemic parameter to detect prediabetes or diabetes, even if 2-hour postload glucose and glycosylated hemoglobin levels can be used as well. We assessed the prevalence of prediabetes and newly diagnosed diabetes with different screening methods, including fasting plasma glucose, 2-hour postload glucose and glycosylated hemoglobin levels in consecutive patients with recent TIA, ischemic stroke or intracerebral hemorrhage admitted to the stroke unit or visiting the specialized TIA outpatient clinic in the Erasmus Medical Center, Rotterdam, The Netherlands.

METHODS

We measured fasting plasma glucose, 2-hour postload glucose and glycosylated hemoglobin levels in 269 patients with a TIA, 374 with ischemic stroke and 57 with intracerebral hemorrhage, all without a history of diabetes mellitus. Prediabetes was defined as fasting plasma glucose levels of 5.6-6.9 mmol/l and/or 2-hour postload glucose levels of 7.8-11.0 mmol/l and/or glycosylated hemoglobin levels of 5.7-6.4%. Newly diagnosed diabetes was defined as fasting plasma glucose levels of ≥7.0 mmol/l and/or 2-hour postload levels of ≥11.1 mmol/l and/or glycosylated hemoglobin levels of ≥6.5%. The diagnosis was based on a one-time measurement.

RESULTS

Based on fasting plasma glucose, 2-hour postload glucose and glycosylated hemoglobin levels combined, 365 patients (52%) were identified as prediabetics and 188 (27%) as having newly diagnosed diabetes. Patients with intracerebral hemorrhage had more often newly diagnosed diabetes compared with patients with an ischemic stroke or a TIA [27 (47%) and 161 (25%), respectively; p < 0.001]; the prevalence of prediabetes was similar. Newly diagnosed diabetes was identified more frequently by 2-hour postload glucose levels (n = 162; 23%) than by fasting plasma glucose (n = 49; 7%) or glycosylated hemoglobin levels (n = 36; 5%). About one third of the patients with normal fasting glucose levels has impaired glucose tolerance or elevated glycosylated hemoglobin levels.

CONCLUSIONS

Prediabetes and newly diagnosed diabetes are highly prevalent in patients with a TIA or stroke. The majority of these patients would not have been identified by fasting plasma glucose levels alone. Both 2-hour postload glucose and glycosylated hemoglobin levels identify more patients with a disturbed glucose metabolism.

Metabolic syndrome with hyperglycemia and the risk of ischemic stroke

PURPOSE

The association of ischemic stroke and metabolic syndrome (MetSyn) with or without diabetes mellitus (DM) is not clear. The present study aimed to identify the impact of diabetes or hyperglycemia on the risk of MetSyn-associated ischemic stroke.

MATERIALS AND METHODS

This study comprised an Asian population of 576 patients with acute nonembolic cerebral infarction and 500 controls. MetSyn was defined according to the criteria of the International Diabetes Federation. MetSyn patients were further subgrouped according to their glucose levels: MetSyn with DM, MetSyn with impaired fasting glucose (IFG) and MetSyn with normal glucose tolerance (NGT). The impact of MetSyn on cerebral infarction was then evaluated.

RESULTS

At baseline, the prevalence of MetSyn in patients with cerebral infarction was higher than that of the controls (57.29% vs. 10.00%, p<0.01). In the stroke group, the prevalences of MetSyn with DM, IFG, and NGT were 25.69%, 8.85% and 22.74%, respectively, all of which were higher than that of the controls (all p-values<0.05). By multiple logistic regression analysis, we discovered that MetSyn was associated with an increased risk of cerebral infarction (odds ratio: 5.73, p<0.01). After adjustment for all the components of MetSyn, the odds ratios of MetSyn with DM, IFG, and NGT were 5.70, 2.24 and 2.19 (all p-values <0.05), respectively.

CONCLUSION

In Asian population, patients with MetSyn accompanied by T2DM are at the greatest risk for acute non-embolic stroke. Additionally, IFG was not observed to be associated with an increased risk for MetSyn-related ischemic stroke.

Metabolic disturbances after acute vascular events: a comparative study of acute coronary syndrome and ischaemic atherothrombotic stroke

OBJECTIVE

This pilot study aimed to compare metabolic disturbances, particularly insulin resistance (IR) and cardiovascular risk factors (CRFs), following two types of acute vascular atherothrombotic disease events: ischaemic atherothrombotic stroke (AS); and acute coronary syndrome (ACS).

DESIGN AND METHODS

A total of 110 non-diabetic patients presenting with either AS (n=55) or ACS (n=55) were included in our prospective comparative study, and matched for age and gender. IR was determined using the homoeostasis model assessment of insulin resistance (HOMA-IR) method, and each patient's personal and family history were also recorded.

RESULTS

IR was significantly higher in the ACS vs AS group (HOMA-IR index 2.17±1.90 vs 1.50±0.81, respectively; P=0.03). The AS group had a significantly higher prevalence of personal history of hypertension (51% vs 31%; P=0.03), while current smoking was more prevalent in the ACS group (30% vs 18%; P=0.04). There were no significant differences between the two groups as regards any other CRFs.

CONCLUSION

The distribution of CRFs varied depending on the vascular event, and metabolic disturbances differed according to the atherothrombotic disease. IR was greater after ACS than AS.

Abnormal Glucose Regulation in Patients With Acute Stroke Across China

Background and Purpose—

The prevalence of diabetes is high among patients with ischemic stroke. However, the prevalence of abnormal glucose regulation and clinical characteristics among patients with stroke in the Chinese population is uncertain. We investigated the prevalence of prediabetes and diabetes in Chinese patients after stroke onset in a nationwide cohort study and investigated abnormal glucose regulation in patients with acute stroke across China (ACROSS-China).

Methods—

The ACROSS-China study consecutively recruited patients hospitalized for acute stroke in 2008 to 2009 and investigated the prevalence of impaired glucose tolerance and diabetes among the patients on day 14 after stroke onset. Oral glucose tolerance test was performed in the diagnosis of abnormal glucose regulation.

Results—

The prevalence of abnormal glucose regulation was 68.7% among all the patients with stroke. Diabetes was identified in 42.3% of all the patients (45.8% for patients with ischemic stroke, 31.2% for patients with intracerebral hemorrhage, and 26.4% for patients with subarachnoid hemorrhage, respectively). Prediabetes (impaired fasting glucose and impaired glucose tolerance) was identified in 26.4% of all the patients with stroke. The prevalence of diabetes and impaired glucose tolerance was the highest in the patients with atherothrombotic infarction (73.4%).

Conclusions—

The prevalence of abnormal glucose regulation was high in Chinese patients with acute stroke, especially in patients with atherothrombotic infarction. Oral glucose tolerance test identified a large percentage of patients with newly diagnosed diabetes or impaired glucose tolerance after stroke onset.

Guidelines for the primary prevention of stroke: a guideline for healthcare professionals from the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

This guideline provides an overview of the evidence on established and emerging risk factors for stroke to provide evidence-based recommendations for the reduction of risk of a first stroke.

METHODS

Writing group members were nominated by the committee chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association (AHA) Stroke Council Scientific Statement Oversight Committee and the AHA Manuscript Oversight Committee. The writing group used systematic literature reviews (covering the time since the last review was published in 2006 up to April 2009), reference to previously published guidelines, personal files, and expert opinion to summarize existing evidence, indicate gaps in current knowledge, and when appropriate, formulate recommendations using standard AHA criteria (Tables 1 and 2). All members of the writing group had the opportunity to comment on the recommendations and approved the final version of this document. The guideline underwent extensive peer review by the Stroke Council leadership and the AHA scientific statements oversight committees before consideration and approval by the AHA Science Advisory and Coordinating Committee.

RESULTS

Schemes for assessing a person's risk of a first stroke were evaluated. Risk factors or risk markers for a first stroke were classified according to potential for modification (nonmodifiable, modifiable, or potentially modifiable) and strength of evidence (well documented or less well documented). Nonmodifiable risk factors include age, sex, low birth weight, race/ethnicity, and genetic predisposition. Well-documented and modifiable risk factors include hypertension, exposure to cigarette smoke, diabetes, atrial fibrillation and certain other cardiac conditions, dyslipidemia, carotid artery stenosis, sickle cell disease, postmenopausal hormone therapy, poor diet, physical inactivity, and obesity and body fat distribution. Less well-documented or potentially modifiable risk factors include the metabolic syndrome, excessive alcohol consumption, drug abuse, use of oral contraceptives, sleep-disordered breathing, migraine, hyperhomocysteinemia, elevated lipoprotein(a), hypercoagulability, inflammation, and infection. Data on the use of aspirin for primary stroke prevention are reviewed.

CONCLUSIONS

Extensive evidence identifies a variety of specific factors that increase the risk of a first stroke and that provide strategies for reducing that risk.

Predicting and preventing stroke after transient ischemic attack

The prognosis of transient ischemic attacks (TIAs) is not as favorable as previously thought. Given a risk of stroke of approximately 10% in the first week following a TIA, urgent evaluation and initiation of treatment are required. Recently developed scores to predict the early risk of subsequent stroke in individual patients may guide treatment decisions in the acute phase. Lately it has become clear that transient attacks with nonfocal symptoms are not benign either, as these were found to be associated with an increased risk of vascular disease. The significance of this finding and its implications for treatment are not yet clear. There is substantial evidence from a number of clinical trials that adequate secondary prevention therapies can reduce the risk of stroke after TIA. In addition to the conventional vascular risk factors, interest has grown in less strong but more prevalent lifestyle factors, but trials evaluating the effect of modifying these factors are as yet lacking.