Insulin resistance is associated with a poor response to intravenous thrombolysis in acute ischemic stroke

Prognostic Value of Fibrosis-4 in Acute Ischemic Stroke Patients Undergoing Intravenous Thrombolysis

Purpose

Although recombinant tissue plasminogen activator (rt-PA) treatment is efficient in patients with acute ischemic stroke (AIS), a significant percentage of patients who received rt-PA intravenous thrombolysis (IVT) do not achieve a good prognosis. Therefore, the factors that affect the poor prognosis of patients with IVT are needed. The Fibrosis-4 (FIB-4) index has been used as a liver fibrosis biomarker. We aimed to investigate the relationship between the FIB-4 index and functional outcomes in patients with AIS receiving IVT.

Patients and Methods

This study prospectively included consecutive patients with AIS receiving IVT between April 2015 and May 2022. We collected clinical and laboratory data and calculated the FIB-4 index. Clinical outcome was poor functional outcome (mRS ≥3) at 3 months after IVT. Multivariate logistic regression analysis was used to analyze the association between FIB-4 and outcome. We explored the interactive effect of FIB-4 and dyslipidemia on poor outcomes, and subgroup analysis was performed. Furthermore, an individualized prediction model based on the FIB-4 for functional outcome was established in the dyslipidemia group.

Results

A total of 1135 patients were included, and 41.50% had poor 3-month outcomes. After adjusted by other variants that P value <0.05 in univariable analysis, FIB-4 was independently associated with poor outcomes (OR=1.420; 95% CI: 1.113-1.812; P=0.004). There was a significant interaction between FIB-4 and dyslipidemia on poor outcome (P=0.036), and the independent association between FIB-4 and poor outcome was maintained in the dyslipidemia subgroup (OR=1.646; 95% CI: 1.228-2.206; P=0.001). Furthermore, in the dyslipidemia group, the FIB-4-based prediction model had good predictive value (the AUC of the training and validation sets were 0.767 and 0.708, respectively), good calibration (P-values for the Hosmer-Lemeshow test >0.05), and clinical usefulness.

Conclusion

FIB-4 is an independent risk factor for poor outcomes in IVT patients with dyslipidemia, which can be used as a simple predictor of their prognosis.

Diabetes and Stroke—A Focused Review

Globally, diabetes mellitus (DM) and stroke are two common chronic illnesses that have a substantial impact on rates of morbidity and mortality. There is significant evidence linking diabetes to an increased risk of stroke in terms of incidence, severity, and mortality. This extensive review looks at shared risk factors, underlying pathophysiological mechanisms, epidemiological trends, and evidence-based therapy approaches to give a thorough analysis of the causal relationship between diabetes mellitus and stroke. Studies using epidemiological data regularly show that people with diabetes have a higher incidence of stroke than people without the disease. Furthermore, diabetes is linked to a less favorable outcome following a stroke, as well as an elevated chance of stroke recurrence. Determining the pathophysiological pathways that connect diabetes and stroke is essential to understanding their relationship. Key pathophysiological processes associated with these disorders include endothelial dysfunction, inflammation, oxidative stress, hyperglycemia, and dyslipidemia. Due to microvascular complications, these mechanisms raise the risk of hemorrhagic stroke and predispose diabetics to an increased risk of ischemic stroke by creating a prothrombotic and atherosclerotic milieu. Diabetes and stroke are linked due to shared risk factors like smoking, obesity, dyslipidemia, hypertension, and poor glycemic control. Lifestyle changes, blood pressure control, lipid-lowering therapy, antiplatelet medicines, and a nutritious diet are essential for stroke risk reduction. Reducing the risk of stroke in people with diabetes requires the implementation of management techniques that focus on both diabetes control and stroke prevention. Optimizing results and lowering the frequency of stroke-related complications in diabetics requires multidisciplinary care. The intricate interactions between diabetes mellitus and stroke are highlighted in this review’s conclusion, which also highlights the value of patient education, risk factor treatment, the effect of antidiabetic therapy on stroke, and integrated care in lowering the incidence of stroke in people with diabetes.

The metabolic score for insulin resistance as a predictor of clinical outcome in stroke patients treated by intravenous thrombolysis

BACKGROUND AND PURPOSE

Insulin resistance is associated with clinical outcomes among patients with ischemic stroke. We aimed to investigate the association between metabolic score for insulin resistance (METS-IR) and clinical outcomes in stroke patients treated by intravenous thrombolysis (IVT).

METHODS

We recruited participants treated with IVT from a prospective registry including 3 stroke centers. Poor outcome was defined as a modified Rankin scale score ≥ 3 points at 90 days after the index stroke. We performed logistic regression models to investigate the association between METS-IR and the risk of poor outcome. We used the receiver operative characteristic to assess the discriminative ability and the restricted cubic spline to explore the relationship between METS-IR and the poor outcome.

RESULTS

This study enrolled a total of 1074 patients (median age, 68; 63.8% male). Three hundred sixty (33.5%) patients had poor outcome after IVT. METS-IR was associated with the risk of the poor outcome with the increase of confounding factors in models (odds ratio [OR], 1.078; 95% confidence interval [CI], 1.058-1.099; P < 0.001). The area under the curve for METS-IR for predicting the poor outcome was 0.790 (95% CI, 0.761-0.819). The restricted cubic spline revealed an increasing and non-linear association between METS-IR and the poor outcome (P for non-linearity < 0.001).

CONCLUSION

Our study found that METS-IR was associated with an increased risk of poor outcome after IVT. Further studies are warranted to investigate the efficacy of anti-diabetic agents regarding IR on clinical outcomes after IVT.

Association between Triglyceride-Glucose Index and Early Neurological Outcomes after Thrombolysis in Patients with Acute Ischemic Stroke

BACKGROUND

The triglyceride-glucose (TyG) index is a novel biomarker of insulin resistance which might plausibly influence endogenous fibrinolysis and thus early neurological outcomes in patients with acute ischemic stroke (AIS) treated with intravenous thrombolysis using recombinant tissue-plasminogen activator.

METHODS

We included consecutive AIS patients within 4.5 h of symptom onset undergoing intravenous thrombolysis between January 2015 and June 2022 in this multi-center retrospective observational study. Our primary outcome was early neurological deterioration (END), defined as ≥2 (END₂) or ≥ 4 (END₄) National Institutes of Health Stroke Scale (NIHSS) score worsening compared to the initial NIHSS score within 24 h of intravenous thrombolysis. Our secondary outcome was early neurological improvement (ENI), defined as a lower NIHSS score at discharge. TyG index was calculated using the log scale of fasting triglyceride (mg/dL) × fasting glucose (mg/dL)/2. We evaluated the association of END and ENI with TyG index using a logistic regression model.

RESULTS

A total of 676 patients with AIS were evaluated. The median age was 68 (Interquartile range, IQR (60-76) years old), and 432 (63.9%) were males. A total of 89 (13.2%) patients developed END₂, 61 (9.0%) patients developed END₄, and 492 (72.7%) experienced ENI. In multivariable logistic regression analysis, after adjustment for confounding factors, TyG index was significantly associated with increased risks of END₂ (categorical variable, vs. lowest tertile, medium tertile odds ratio [OR] 1.05, 95% confidence interval, CI 0.54-2.02, highest tertile OR 2.94, 95%CI 1.64-5.27, overall p < 0.001) and END₄ (categorical variable, vs. lowest tertile, medium tertile OR 1.21, 95%CI 0.54-2.74, highest tertile OR 3.80, 95%CI 1.85-7.79, overall p < 0.001), and a lower probability of ENI (categorical variable, vs. lowest tertile, medium tertile OR 1.00, 95%CI 0.63-1.58, highest tertile OR 0.59, 95%CI 0.38-0.93, overall p = 0.022).

CONCLUSIONS

Increasing TyG index was associated with a higher risk of END and a lower probability of ENI in patients with acute ischemic stroke treated with intravenous thrombolysis.

The Pre-Stroke Induction and Normalization of Insulin Resistance Respectively Worsens and Improves Functional Recovery

Type 2 diabetes (T2D) impairs post-stroke recovery, and the underlying mechanisms are unknown. Insulin resistance (IR), a T2D hallmark that is also closely linked to aging, has been associated with impaired post-stroke recovery. However, whether IR worsens stroke recovery is unknown. We addressed this question in mouse models where early IR, with or without hyperglycemia, was induced by chronic high-fat diet feeding or sucrose supplementation in the drinking water, respectively. Furthermore, we used 10-month-old mice, spontaneously developing IR but not hyperglycemia, where IR was normalized pharmacologically pre-stroke with Rosiglitazone. Stroke was induced by transient middle cerebral artery occlusion and recovery was assessed by sensorimotor tests. Neuronal survival, neuroinflammation and the density of striatal cholinergic interneurons were also assessed by immunohistochemistry/quantitative microscopy. Pre-stroke induction and normalization of IR, respectively, worsened and improved post-stroke neurological recovery. Moreover, our data indicate a potential association of this impaired recovery with exacerbated neuroinflammation and a decreased density of striatal cholinergic interneurons. The global diabetes epidemic and population aging are dramatically increasing the percentage of people in need of post-stroke treatment/care. Our results suggest that future clinical studies should target pre-stroke IR to reduce stroke sequelae in both diabetics and elderly people with prediabetes.

A Novel Metabolic Score for Insulin Resistance and Symptomatic Intracranial Hemorrhage in Ischemic Stroke Patients After Endovascular Thrombectomy

BACKGROUND AND PURPOSE

Insulin resistance plays a pivotal role in the pathophysiology of ischemic stroke. This study aimed to determine the relationship between the novel metabolic score for insulin resistance (METS-IR) and symptomatic intracranial hemorrhage (sICH) after endovascular thrombectomy (EVT) in stroke patients.

METHODS

We retrospectively included patients with large artery occlusion in the anterior circulation and treated by EVT from 2 stroke centers (Nanjing First Hospital from September 2019 to April 2022, and Jinling Hospital from September 2019 to July 2021). The METS-IR was used as an alternative marker of insulin resistance and calculated using laboratory data after admission. sICH was diagnosed according to the Heidelberg Bleeding Classification.

RESULTS

Of the 410 enrolled patients (mean age, 69.8 ± 11.7 years; 60.7% men), 50 (12.2%) were diagnosed as sICH. After adjusting for demographic characteristics, poor collateral status, and other potential confounders, higher METS-IR was revealed to be independently associated with sICH (odds ratio, 1.076; 95% confidence interval, 1.034-1.120; P = 0.001). Similar significant results were obtained when defining METS-IR as a categorical variable. The restricted cubic spline uncovered a linear relationship between METS-IR and sICH (P < 0.001 for linearity). Furthermore, adding METS-IR to the conventional model significantly improved the risk prediction for sICH (net reclassification improvement = 15.8%, P = 0.035; integrated discrimination index = 2.6%; P = 0.017).

CONCLUSION

This study demonstrated a significant association between METS-IR score and sICH in ischemic stroke patients treated with EVT. It could help monitor and manage sICH in patients after EVT.

Correlation of Insulin Resistance With Short-Term Outcome in Nondiabetic Patients With ST-Segment Elevation Myocardial Infarction

BACKGROUND

 Obviously, hyperglycemia and insulin resistance (IR) are common in patients with acute ST-segment elevation myocardial infarction (STEMI). Additionally, IR is a substantial risk factor for cardiovascular diseases. The study aims to evaluate the association between IR and short-term outcomes of acute STEMI patients without diabetes mellitus in the form of reperfusion success, the occurrence of heart failure, the development of arrhythmias, and mortality.

METHOD

 A cross-sectional study was done from August 2021 to December 2021 in two cardiology centers in Al-Sadr Teaching hospital and Basrah Oil hospital in Basrah, Southern Iraq. Sixty-one nondiabetic hospitalized patients with acute STEMI were included in the study. Twenty-five (41%) of them received thrombolytics and 36 (59%) were managed with percutaneous transluminal coronary angioplasty. From each patient, a fasting blood sample was taken for calculation of the Homeostasis Model Assessment for IR (HOMA-IR) and triglyceride glucose index (TyG) index. The patients were evaluated within 1-week for (reperfusion success, echocardiography for calculation of the ejection fraction (EF), arrhythmias, and mortality), and within 4-weeks for mortality.

RESULTS

 Within the tertile 3 of the HOMA-IR and TyG index, significant higher 4-week mortality (35% and 30%, respectively). Pearson correlation also showed significant and negative correlations between both HOMA-IR and TyG index values and EF. While reperfusion success, arrhythmias, and 1-week mortality did not correlate significantly with both HOMA-IR and TyG index.

CONCLUSION

 IR as defined by HOMA-IR and TyG index was significantly associated with poor outcomes in patients with acute STEMI in the form of EF<55 and 4-week mortality.

The potential role of insulin resistance in predicting outcome from intravenous thrombolytic therapy

Background

The potential impact of insulin resistance on stroke prognosis after IV thrombolysis is poorly understood. This study aimed to assess the effect of insulin resistance and metabolic syndrome on the outcome of IV thrombolysis in non-diabetic patients with acute ischaemic stroke.

Methods

This prospective observational study was conducted on 70 non-diabetic acute ischaemic stroke patients who received rt-PA within 3 h of stroke onset. Patients were subjected to baseline and follow-up NIHSS measurements at 24 h and 3 months post-treatment. Stroke outcome was assessed after 3 months using the Modified Rankin Scale (mRS). The homeostasis model assessment–insulin resistance (HOMA-IR) was calculated for the included patients at stroke onset.

Results

The mean age of included patients was 57.04 ± 14.39 years. Patients with unfavourable outcome had a significantly higher frequency of insulin resistance and metabolic syndrome, higher values of baseline NIHSS, insulin, HOMA-IR, uric acid and lower levels of HDL than those with favourable outcome (P value = 0.035, 0.007, ≤ 0.001, 0.001, ≤ 0.001, 0.002, 0.033, respectively). Each point increase in NIHSS before rt-PA increased the odds of an unfavourable outcome by 2.06 times (95% CI 1.22 − 3.478). Also, insulin resistance increased the odds of the unfavourable outcome by 11.046 times (95% CI 1.394–87.518). There was a statistically significant improvement in NIHSS 3 months after receiving rt-PA in all patients, significantly higher in patients who did not have insulin resistance or metabolic syndrome.

Conclusion

Insulin resistance and metabolic syndrome were associated with worse functional outcomes in non-diabetic stroke patients after receiving rt-PA.

The effect of metabolic syndrome and/or hyperglycemia on outcomes of acute ischemic stroke patients treated with intravenous thrombolysis

BACKGROUNDS AND OBJECTIVES

The impact of metabolic syndrome (MetS)/hyperglycemia on the clinical outcomes of ischemic stroke treated with intravenous thrombolysis (IVT) remains controversial. This study aimed to determine the risks conferred by MetS and hyperglycemia to clinical outcomes in acute ischemic stroke patients treated with IVT.

METHOD

Three hundred forty-three ischemic stroke patients treated with IVT were prospective recruited and stratified into four groups: neither, MetS only, hyperglycemia only, or both. The primary outcome was the 3-month poor functional outcome (PFO) which was defined as a 3-month modified Rankin Score (mRS) score ≧3. The secondary outcome included the hemorrhagic transformation (HT) and symptomatic intracranial hemorrhage (sICH) after IVT.

RESULTS

MetS was recognized in 197 (57.43%) patients. During the first 24 h after IVT, 44 (12.83%) patients had HT, of which 17 had sICH. Three-month PFO was found in 98 (28.57%) patients. After adjustment for potential confounders, MetS (odds ratio (OR) = 3.140, 95% confidence interval (CI) = 1.724-5.718) was independently associated with PFO. However, neither MetS nor its components were associated with 24-h HT or sICH. In the further subgroup analysis, we used the "neither" group as reference and found that the presence of both MetS and hyperglycemia (OR = 3.192, 95% CI = 1.338-7.615) and the presence of hyperglycemia only (OR = 2.097, 95% CI = 1.052-4.179) were significantly related to the 3-month PFO.

CONCLUSION

MetS is an independent risk factor on 3-month PFO in acute ischemic stroke patients treated with IVT. Compared with "neither," hyperglycemia only or concurrent with MetS was associated with an elevated risk of PFO after receiving IVT.

Triglyceride-Glucose Index and Intravenous Thrombolysis Outcomes for Acute Ischemic Stroke: A Multicenter Prospective–Cohort Study

Background

The triglyceride-glucose (TyG) index has recently been proposed as a reliable marker of insulin resistance. There is insufficient evidence to verify that the TyG index is correlated with functional outcomes and hemorrhagic transformation and in patients with stroke treated with intravenous thrombolysis (IVT).

Methods

We designed a multicenter cohort study, which enrolled patients with acute ischemic stroke treated with IVT between December 2004 and December 2016. The TyG index was divided into tertiles and calculated on a continuous scale. Unfavorable functional outcomes were defined by the modified Rankin Scale of 3–6 at 90 days and the incident rates of symptomatic intracranial hemorrhage (SICH) within 36 h of IVT onset were surveyed. Stroke severity was defined as mild (4–8), moderate (9–15), or high (≥16) based on the National Institutes of Health Stroke Scale (NIHSS) scores.

Results

Among 914 enrolled patients, the tertiles of the TyG index were 8.48 for T1, 8.48–9.04 for T2, and 9.04 for T3. T3 showed an increased risk of unfavorable functional outcomes at 90 days [odds ratio (OR): 1.76; P = 0.0132]. The TyG index was significantly associated with unfavorable functional outcomes at 90 days (OR: 1.32; P = 0.0431 per unit increase). No association was found between the TyG index and SICH. These findings were applicable for T3 with stroke of moderate (OR, 2.35; P = 0.0465) and high severity (OR: 2.57, P = 0.0440) patients with stroke.

Conclusion

This study supports the strong association between the increased TyG index and increased unfavorable functional outcomes at 90 days in patients with acute ischemic stroke treated with IVT. These findings were found to be robust in patients with moderate and high stroke severity.

L-carnitine supplementation ameliorates insulin resistance in critically ill acute stroke patients: a randomized, double-blinded, placebo-controlled clinical trial

BACKGROUND AND PURPOSE

Insulin resistance (IR) can negatively affect clinical outcomes in acute ischemic stroke (IS) patients. Safe and cost-saving interventions are still needed to improve glycemic indices in this population. The primary objective was to evaluate L-carnitine (LC) effects in acute IS patients' homeostatic model assessment of IR (HOMA-IR).

EXPERIMENTAL APPROACH

In this randomized, double-blind placebo-controlled clinical trial, critically ill IS patients were allocated to receive daily oral L-carnitine (1.5 g) or a placebo for six days. Fasting serum levels of glucose, insulin, C-reactive protein, LC, and HOMA-IR were measured on days 1 and 7. Mechanical ventilation duration, ICU/hospital duration, illness severity score, sepsis, and death events were assessed.

FINDINGS/RESULTS

Forty-eight patients were allocated to the research groups, 24 patients in each group, and all were included in the final analysis. LC administration showed a decrease in mean difference of HOMA-IR and insulin levels at day 7 compared to placebo, -0.94 ± 1.92 vs 0.87 ± 2.24 (P = 0.01) and -2.26 ± 6.81 vs 0.88 ± 4.95 (P = 0.03), respectively. However, LC administration did not result in significant improvement in clinical outcomes compared to placebo. The short duration of intervention and low sample size limited our results.

CONCLUSION AND IMPLICATION

Supplementation of L-carnitine improved HOMA-IR index in acute IS patients admitted to the critical care unit. Supplementation of LC would be a potential option to help to control IR in critically ill acute IS patients.

Association of triglyceride-glucose index with clinical outcomes in patients with acute ischemic stroke receiving intravenous thrombolysis

Intravenous tissue plasminogen activator (tPA) remains the cornerstone of recanalization therapy for acute ischemic stroke (AIS), albeit with varying degrees of response. The triglyceride-glucose (TyG) index is a novel marker of insulin resistance, but association with outcomes among AIS patients who have received tPA has not been well elucidated. We studied 698 patients with AIS who received tPA from 2006 to 2018 in a comprehensive stroke centre. TyG index was calculated using the formula: ln[fasting triglycerides (mg/dL) × fasting glucose (mg/dL)/2]. TyG index was significantly lower in patients that survived at 90-days than those who died (8.61 [Interquartile Range: 8.27-8.99] vs 8.76 [interquartile range: 8.39-9.40], p = 0.007). In multivariate analysis, TyG index was significantly associated with 90-day mortality (OR: 2.12, 95% CI: 1.39-3.23, p = 0.001), poor functional outcome (OR: 1.41 95% CI: 1.05-1.90, p = 0.022), and negatively associated with early neurological improvement (ENI) (OR: 0.68, 95% CI: 0.52-0.89, p = 0.004). There was no association between TyG index and symptomatic intracranial hemorrhage. 'High TyG' (defined by TyG index ≥ 9.15) was associated with mortality, poor functional outcomes and no ENI. In conclusion, the TyG index, a measure of insulin resistance, was significantly associated with poorer clinical outcomes in AIS patients who received tPA.

Predictive Value of Insulin Resistance as Determined by Homeostasis Model Assessment in Acute Ischemic Stroke Patients: A Systematic Review and Meta-Analysis

Studies on association between homeostasis model assessment of insulin resistance (HOMA-IR) and adverse outcomes have yielded conflicting results in patients with acute ischemic stroke (AIS). This meta-analysis aimed to assess the predictive value of HOMA-IR in AIS patients. Two authors comprehensively searched PubMed and Embase databases until February 28, 2021. All observational studies investigating the association between HOMA-IR and adverse outcomes in AIS patients were included. Outcome measures were poor functional outcome (Modified Rankin Scale≥3), all-cause mortality, stroke recurrence, and neurologic worsening. Seven studies (eight articles) involving 8330 AIS patients were identified. For the highest versus lowest HOMA-IR, the pooled risk ratio (RR) of poor functional outcome was 2.55 (95% CI 1.76-3.70) after adjustment of conventional confounding factors. In addition, elevated HOMA-IR was associated with higher risk of neurologic worsening (RR 1.93; 95% CI 1.15-3.26). However, there were conflicting findings on the association of HOMA-IR with stroke recurrence and all-cause mortality. This meta-analysis confirms that HOMA-IR is significantly associated with an increased risk of poor functional outcome in patients with AIS. However, interpretation of the results of mortality, stroke recurrence, and neurologic worsening should be done with caution due to small number of studies available.

Cardioprotective Effects of Pioglitazone in Type 2 Diabetes

Antidiabetic medications that improve glycemic control as well as cardiovascular outcomes will be the mainstay of treatment for type 2 diabetes moving forward. This article reviews the beneficial effects of the thiazolidinedione pioglitazone of ameliorating hyperglycemia and improving cardiovascular risk factors. While the newer sodium-glucose cotransporter 2 inhibitor and glucagon-like peptide 1 receptor agonist drug classes have confirmed cardiovascular benefits, pioglitazone also has been shown to reduce major adverse cardiovascular events, in both people with type 2 diabetes and nondiabetic subjects with insulin resistance. Adverse effects associated with pioglitazone can be mitigated by its use at a lower dose and in combination with antidiabetic agents from other drug classes.

High Triglyceride Glucose Index Is Associated with Poor Outcomes in Ischemic Stroke Patients after Reperfusion Therapy

INTRODUCTION

The triglyceride glucose index (TyG index) is a simple and reliable surrogate marker of insulin resistance (IR) that can predict functional outcomes and mortality after acute ischemic stroke (AIS). However, it is unclear whether the TyG index is associated with functional outcomes in patients with stroke who receive reperfusion therapy. Thus, we aimed to explore the prognostic value of the TyG index for the clinical outcomes of patients with AIS who underwent reperfusion therapy.

METHODS

We retrospectively assessed patients with AIS, with occlusion of either the middle cerebral artery or internal carotid artery, who were evaluated using multiphase computed tomography angiography (mCTA) and received reperfusion therapy. The TyG index was calculated as "ln [fasting glucose level (mg/dL) × triglyceride level (mg/dL)]/2." Collateral status was evaluated using mCTA based on the University of Calgary Scale. Clinical outcomes included 3-month functional outcomes, early neurological deterioration, recanalization status, and hemorrhagic transformation.

RESULTS

In all, 183 subjects (age 69.5 ± 12.4 years; men, 59.0%) were enrolled. The median initial National Institutes of Health Stroke Scale score was 15.0 (interquartile range [IQR] 11-18). The median TyG index was 4.8 (IQR, 4.6-5.1), and 158 patients had TyG levels >4.49, which represents the presence of IR. On univariate analysis, a higher TyG index was associated with both early neurological deterioration (18.4 vs. 0.0%, p = 0.041) and a 3-month poor functional outcome (mRS3-6) (61.4 vs. 32.0%, p = 0.011). After adjusting for multiple variables, including age, sex, type of reperfusion therapy, recanalization status, initial stroke severity, type of stroke, and history of hypertension and diabetes, high TyG index remained an independent predictor of a poor 3-month functional outcome (adjusted OR, 5.22; p = 0.014). However, TyG levels were not significantly associated with collateral status (p = 0.756).

CONCLUSIONS

IR, represented by a high TyG index, may predict poor 3-month functional outcomes in patients with AIS who undergo reperfusion therapy.

The relationship between insulin sensitivity and serum antithrombin 3 activity in patients with type 2 diabetes

BACKGROUND

Antithrombin 3 (AT3) is a physiological inhibitor of thrombin, and serum AT3 activity was found to decrease at the status of type 2 diabetes (T2D). T2D was presented with an increased risk of thrombotic complications at the background of impaired insulin sensitivity. The aim of this study was to investigate the relationship between insulin sensitivity indices and serum AT3 activity in patients with T2D.

METHODS

We conducted a cross-sectional study in patients with T2D who consented to participate in the study at the Endocrinology Department of Affiliated 2 Hospital of Nantong University from January 2015 to June 2018. All patients received serum AT3 activity test and 75 g oral glucose tolerance test (OGTT). Basal and systemic insulin sensitivity were assessed by homeostasis model assessment of insulin resistance (HOMA-IR) and Matsuda index (ISIMatsuda), respectively, from the OGTT. And other relevant clinical data were also collected.

RESULTS

Total of 1612 patients with T2D were enrolled in the study, with a mean age of 58.67 ± 13.09 years and a median diabetes duration of 6 years (interquartile range, 1-10 years). Across ascending quartiles of serum AT3 activity, HOMA-IR progressively decreased, while ISIMatsuda progressively increased (all P for trend < 0.001). Moreover, serum AT3 activity was negatively correlated with HOMA-IR (r = -0.189, P < 0.001) and positively correlated with ISIMatsuda (r = 0.221, P < 0.001). After adjusting for other metabolic risk factors, hemostatic parameters and glucose-lowering therapies by multivariate linear regression analysis, HOMA-IR (β = -0.185, t = -5.960, P < 0.001) and ISIMatsuda (β = 0.197, t = 6.632, P < 0.001) remained independently associated with the serum AT3 activity in patients with T2D, respectively.

CONCLUSIONS

Reduced basal and systemic insulin sensitivity are associated with decreased serum AT3 activity in patients with T2D.

Association between insulin resistance and aspirin or clopidogrel resistance in Chinese patients with recent ischemic stroke/TIA

Objective: This study aims to discover whether insulin resistance is an independent predictor for antiplatelet drug resistance in patients with ischemic cerebrovascular disease.Methods: This study used a prospective cohort method. Patients diagnosed as minor ischemic stroke or transient ischemic attack (TIA) were enrolled successively. All patients have been administrated aspirin and/or clopidogrel and were tested for fasting glucose and insulin and platelet aggregation inhibition tests which was detected by light transmission aggregometry (LTA). The maximum platelet aggregation rate (AA) of ≥20% or the maximum platelet aggregation rate (ADP) of ≥50% was defined as antiplatelet drug resistance. Multivariable logistic regression was performed to estimate the association between HOMA-IR and antiplatelet drug resistance.Results: This study recruited successively 237 patients with mild-to-moderate ischemic stroke or TIA in Beijing Tiantan Hospital from 2018 to 2019. Of them 60 cases were recognized as having insulin resistance. There are 46 patients in insulin resistance group (76.7%) developed antiplatelet drug resistance, which was significantly more frequent than patients without insulin resistance (35%, P < 0.0001). Insulin resistance was an independent risk factor for antiplatelet drug resistance in patients with recent ischemic stroke/TIA after adjusted for confounding factors (Odds Ratio 5.281; 95%CI, 2.15 to 13.01, P < 0.0001).Conclusions: Insulin resistance was an independent predictor for development of antiplatelet drug resistance in patients with recent minor ischemic stroke or TIA. More attention should be paid to recognize these patients and antithrombotic effect should be monitored when antiplatelet drugs were applied to these patients.

Insulin resistance is associated with poor functional outcome after acute ischemic stroke in non-diabetic patients

Insulin resistance is associated with the occurrence of stroke and atherosclerotic disease. However, the relationship between insulin resistance and the prognosis of acute ischemic stroke in non-diabetic patients is unclear. We hypothesized that insulin resistance might affect short-term functional recovery after acute ischemic stroke in non-diabetic patients. Between May 2014 and December 2016, 1377 consecutive patients with acute ischemic stroke were enrolled from a prospectively maintained stroke registry. After excluding patients with transient ischemic attacks (TIA), pre-stroke disabilities, diabetes mellitus, and patients with incomplete evaluations, 517 patients were included in the study. The homeostasis model assessment of insulin resistance (HOMA-IR) score was used to evaluate the degree of insulin resistance. The patients with the highest quartile of log HOMA-IR index scores were younger and had higher fasting blood glucose, total cholesterol, triglycerides, low-density lipoprotein, and HbA1c levels. Multivariable logistic regression analysis revealed that log HOMA-IR scores were independently associated with poor prognosis after adjusting for age and sex and p < 0.1 in univariable analysis. Insulin resistance was associated with the poor functional outcome of non-diabetic stroke patients. This evidence supports treating insulin resistance in acute ischemic stroke patients with blood glucose levels within the normal range.

Homeostasis model assessment of insulin resistance and outcome of ischemic stroke in non-diabetic patients - a prospective observational study

Background

Insulin resistance (IR) in relation to diabetes is a risk factor for ischemic stroke (IS), whereas less is known about non-diabetic IR and outcome after IS.

Methods

In non-diabetic IS (n = 441) and controls (n = 560) from the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS), IR was investigated in relation to IS severity and functional outcome. IR was evaluated acutely and after 3 months using the Homeostasis model assessment of IR (HOMA-IR). Stroke severity was assessed by the National Institutes of Health Stroke Scale (NIHSS). Functional outcome was evaluated using the modified Rankin Scale (mRS) after 3 months, 2 and 7 years. Associations were evaluated by logistic regression.

Results

Higher acute and 3-month HOMA-IR was observed in IS compared to the controls (both p < 0.001) and in severe compared to mild IS (both p < 0.05). High acute HOMA-IR was associated with poor outcome (mRS 3–6) after 3 months and 7 years [crude Odds ratios (ORs), 95% confidence intervals (CIs) 1.50, 1.07–2.11 and 1.59, 1.11–2.30, respectively], but not after 2 years. These associations lost significance after adjustment for all covariates including initial stroke severity. In the largest IS subtype (cryptogenic stroke), acute HOMA-IR was associated with poor outcome after 2 years also after adjustment for age and stroke severity (OR 2.86, 95% CI 1.01–8.12).

Conclusions

In non-diabetic IS patients, HOMA-IR was elevated and related to stroke severity, but after adjustment for IS severity, the associations between HOMR-IR and poor outcome lost significance. This could suggest that elevated IR mostly is a part of the acute IS morbidity. However, in the subgroup of cryptogenic stroke, the associations with poor outcome withstood correction for stroke severity.

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.

Insulin resistance as estimated by homeostasis model assessment predicts incident post-stroke depression in Chinese subjects from ischemic stroke

OBJECTIVE

Previous studies suggested that insulin resistance (IR) may be a significant causal risk factor for cardiovascular events and depression independent of other risk factors. In this prospective, we assess the value of Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) at admission to predict post-stroke depression (PSD) later developed at 3 months follow-up.

METHODS

This prospective, multicenter cohort study was conducted from January 2015 through December 2016 in China. Clinical information and HOMA-IR was assessed at admission. Neurological and neuropsychological evaluations were conducted at the 3-month follow-up.

RESULTS

In the study population, 56.6% were male and the median age was 59 years (interquartile range [IQR]: 51-69). One hundred and eighty-six patients (26.6%) showed depression at 3 months after admission and in 53 patients (28.5%) this depression was classified as severe. For each 1-unit increase of HOMA-IR, the unadjusted and adjusted risk of PSD increased by 63% (odds ratios [OR]: 1.63; 95% confidence interval [CI]:1.44-1.85; P < 0.001) and 27% (1.27; 1.13-1.39; P = 0.002). In a multivariate model using the fourth quartiles of HOMA-IR vs. quartiles 1 through 3 together with the clinical variables, the marker displayed prognostic information (PSD: OR for fourth quartile, 2.76 [95% CI, 1.66-3.73; P = 0.003]).

CONCLUSIONS

The data suggests that the HOMA-IR may be of potential clinical relevance in identifying stroke patients at risk of developing depression, independent of the well-established predictors.

Insulin resistance and clinical outcomes after acute ischemic stroke

Objective

In this study, we aimed to determine whether insulin resistance is associated with clinical outcomes after acute ischemic stroke.

Methods

We enrolled 4,655 patients with acute ischemic stroke (aged 70.3 ± 12.5 years, 63.5% men) who had been independent before admission; were hospitalized in 7 stroke centers in Fukuoka, Japan, from April 2009 to March 2015; and received no insulin therapy during hospitalization. The homeostasis model assessment of insulin resistance (HOMA-IR) score was calculated using fasting blood glucose and insulin levels measured 8.3 ± 7.8 days after onset. Study outcomes were neurologic improvement (≥4-point decrease in NIH Stroke Scale score or 0 at discharge), poor functional outcome (modified Rankin Scale score of ≥3 at 3 months), and 3-month prognosis (stroke recurrence and all-cause mortality). Logistic regression analysis was used to evaluate the association of the HOMA-IR score with clinical outcomes.

Results

The HOMA-IR score was associated with neurologic improvement (odds ratio, 0.68 [95% confidence interval, 0.56–0.83], top vs bottom quintile) and with poor functional outcome (2.02 [1.52–2.68], top vs bottom quintile) after adjusting for potential confounding factors, including diabetes and body mass index. HOMA-IR was not associated with stroke recurrence or mortality within 3 months of onset. The associations were maintained in nondiabetic or nonobese patients. No heterogeneity was observed according to age, sex, stroke subtype, or stroke severity.

Conclusions

These findings suggest that insulin resistance is independently associated with poor functional outcome after acute ischemic stroke apart from the risk of short-term stroke recurrence or mortality.

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.

The effect of exercise preconditioning on stroke outcome in ovariectomized mice with permanent middle cerebral artery occlusion

Exercise preconditioning has been shown to be effective in improving behavioral and neuropathological indices after cerebral ischemia. We evaluated the effect of exercise preconditioning, 17β-estradiol, and their combination on stroke outcome using an experimental model of stroke in ovariectomized (OVX) mice. OVX mice were randomly assigned to 4 groups as follows: control (stroke), exercise (exercise and stroke), estradiol (17β-estradiol and stroke), and exercise+estradiol (exercise and 17β-estradiol and stroke). Exercise preconditioning was performed on a treadmill 5 days/week, 40 min/day, at a speed of 18 m/min for 4 weeks. 17β-estradiol was gavaged (40 μg/kg per day) for 4 weeks. Stroke was induced by permanent middle cerebral artery occlusion (pMCAO), and neurological deficits were evaluated 1, 2, and 7 days after stroke. Then, the serum concentrations of matrix metalloproteinase-9 (MMP-9) and interleukin-10 (IL-10) and infarct volumes were assessed. Exercise preconditioning and 17β-estradiol induced a better outcome compared with the control ischemic mice, which was manifested by decrease in MMP-9, increase in IL-10, diminished infarct volume, and improved neurological deficits. Concomitant administration of 17β-estradiol and exercise also significantly improved these parameters. Exercise preconditioning or administration of 17β-estradiol alone or in combination before pMCAO induced significant neuroprotection in OVX mice.

The Impact of Discrepancy between Measured versus Stated Weight on Hemorrhagic Transformation and Clinical Outcomes after Intravenous Alteplase Thrombolysis

BACKGROUND

An accurate measurement of patient weight is important in determining the dosage for intravenous alteplase thrombolysis. In most emergency rooms, however, weight is not measured. We investigated the difference between stated and measured weight and its effect on hemorrhagic transformation and clinical outcomes.

METHODS

We enrolled 128 consecutive patients who had hyperacute stroke and were treated by alteplase. Alteplase dose was calculated using the weight provided by patient or guardian/caregiver, and the actual weight was measured after administration. Patients were classified into 2 groups: overused group (stated weight >measured weight) and underused group (measured weight ≥stated weight). The prevalence of hemorrhagic transformation on follow-up, determined by gradient-recalled echo MRI or non-enhanced CT, was compared between the 2 groups. The predictors for hemorrhage with progression, defined as an increase in the National Institutes of Health Stroke Scale (NIHSS) by a value of 4 or more accompanied by hemorrhage, were determined using multivariable logistic regression analysis and included the overused or underused alteplase and baseline clinical and laboratory findings.

RESULTS

Sixty-six (51.6%) of 128 patients were in the underused group and 62 patients (48.4%) in the overused group. The median difference between the stated and measured weights was 1.5 (interquartile range 0.56-3.81) kg, with the largest difference being 25.6 kg. Although there were no significant difference in baseline clinical and laboratory findings between the 2 groups, the overused group showed a significantly higher prevalence of hemorrhagic transformation (p = 0.012) and hemorrhage with progression (p = 0.025). The multivariable logistic regression analysis demonstrated that overused alteplase (OR 7.26; 95% CI 1.24-42.45; p = 0.028), baseline glucose (>144 mg/dL; OR 5.03; 95% CI 1.00-25.26; p = 0.050), and initial NIHSS (OR 1.13 per 1-point NIHSS increase; 95% CI 1.00-1.27; p = 0.047) in model 1 that use alteplase overdose as a categorical variable and overused alteplase (OR 1.67 1-mg increase; 95% CI 1.05-2.66; p = 0.027) in model 2 that use an overused alteplase dose as numerical variable were significant predictors for hemorrhage with progression.

CONCLUSION

More alteplase usage than actual weight led to higher hemorrhagic transformation. As one of the predictors for clinical deterioration, it is important to administrate alteplase based on an accurately measured weight.

Insulin Resistance and Prognosis of Nondiabetic Patients With Ischemic Stroke: The ACROSS-China Study (Abnormal Glucose Regulation in Patients With Acute Stroke Across China)

BACKGROUND AND PURPOSE

Insulin resistance was common in patients with stroke. This study investigated the association between insulin resistance and outcomes in nondiabetic patients with first-ever acute ischemic stroke.

METHODS

Patients with ischemic stroke without history of diabetes mellitus in the ACROSS-China registry (Abnormal Glucose Regulation in Patients With Acute Stroke Across China) were included. Insulin resistance was defined as a homeostatis model assessment-insulin resistance (HOMA-IR) index in the top quartile (Q4). HOMA-IR was calculated as fasting insulin (μU/mL)×fasting glucose (mmol/L)/22.5. Multivariable logistic regression or Cox regression was performed to estimate the association between HOMA-IR and 1-year prognosis (mortality, stroke recurrence, poor functional outcome [modified Rankin scale score 3-6], and dependence [modified Rankin scale score 3-5]).

RESULTS

Among the 1245 patients with acute ischemic stroke enrolled in this study, the median HOMA-IR was 1.9 (interquartile range, 1.1-3.1). Patients with insulin resistance were associated with a higher mortality risk than those without (adjusted hazard ratio, 1.68; 95% confidence interval, 1.12-2.53; P=0.01), stroke recurrence (adjusted hazard ratio, 1.57, 95% confidence interval, 1.12-2.19; P=0.008), and poor outcome (adjusted odds ratio, 1.42; 95% confidence interval, 1.03-1.95; P=0.03) but not dependence after adjustment for potential confounders. Higher HOMA-IR quartile categories were associated with a higher risk of 1-year death, stroke recurrence, and poor outcome (P for trend =0.005, 0.005, and 0.001, respectively).

CONCLUSIONS

Insulin resistance was associated with an increased risk of death, stroke recurrence, and poor outcome but not dependence in nondiabetic patients with acute ischemic stroke.

Post-Glucose Load Measures of Insulin Resistance and Prognosis of Nondiabetic Patients With Ischemic Stroke

Background

Insulin resistance is associated with an increased risk of cardiovascular events in the general population. This study aimed to estimate the association between post–glucose load measures of insulin resistance and prognosis of nondiabetic patients with ischemic stroke.

Methods and Results

Data were derived from the ACROSS‐China (Abnormal Glucose Regulation in Patients with Acute Stroke across China) registry. Patients with ischemic stroke without a history of diabetes mellitus were included. Two post–glucose load measures of insulin sensitivity, the insulin sensitivity indices ISI(composite) and the ISI_0,120, were calculated. Outcomes included stroke recurrence, all‐cause death, and poor functional outcome at 12 months. Among 1203 patients, 63.3% were male with an average age of 62.1 years. At 12 months, 168 (14.4%) patients had recurrent stroke, 111 (9.2%) had died, and 288 (24.4%) had poor outcome. After adjustment for potential covariates, the first quartile of the ISI(composite) was associated with increased 12‐month stroke recurrence (adjusted hazard ratio 2.02, 95% CI 1.28–3.18, P=0.003), death (adjusted hazard ratio 2.78, 95% CI 1.59–4.86, P<0.001), and poor outcome (adjusted odds ratio 2.67, 95% CI 1.69–4.21, P<0.001) compared with the fourth quartile. Similar results were observed for the ISI_0,120 but with a larger magnitude of association. Using a multivariable regression model with restricted cubic spline, we found an L‐shaped association between the insulin sensitivity indices and the risk of each end point.

Conclusions

In this large‐scale registry, post–glucose load measures of insulin resistance with the ISI(composite) and the ISI_0,120 were associated with 12‐month poor outcomes of nondiabetic patients with ischemic stroke.

Fermented soybeans, Chungkookjang, prevent hippocampal cell death and β-cell apoptosis by decreasing pro-inflammatory cytokines in gerbils with transient artery occlusion

Since Chungkookjang, a short-term fermented soybean, is known to improve glucose metabolism and antioxidant activity, it may prevent the neurological symptoms and glucose disturbance induced by artery occlusion. We investigated the protective effects and mechanisms of traditional (TFC) and standardized Chungkookjang fermented with Bacillus licheniformis (BLFC) against ischemia/reperfusion damage in the hippocampal CA1 region and against hyperglycemia after transient cerebral ischemia in gerbils. Gerbils were subjected to either an occlusion of the bilateral common carotid arteries for 8 min to render them ischemic or a sham operation. Ischemic gerbils were fed either a 40% fat diet containing 10% of either cooked soybean (CSB), TFC, or BLFC for 28 days. Neuronal cell death and cytokine expression in the hippocampus, neurological deficit, serum cytokine levels, and glucose metabolism were measured. TFC and BLFC contained more isoflavonoid aglycones than CSB. Artery occlusion increased the expressions of IL-1β and TNF-α as well as cell death in the hippocampal CA1 region and induced severe neurological symptoms. CSB, TFC, and BLFC prevented the neuronal cell death and the symptoms such as dropped eyelid, bristling hair, reduced muscle tone and flexor reflex, and abnormal posture and walking patterns, and suppressed cytokine expressions. CSB was less effective than TFC and BLFC. Artery occlusion induced glucose intolerance due to decreased insulin secretion and β-cell mass. TFC and BLFC prevented the impairment of glucose metabolism by artery occlusion. Especially TFC and BLFC increased β-cell proliferation and suppressed the β-cell apoptosis by suppressing TNF-α and IL-1β which in turn decreased cleaved caspase-3 that caused apoptosis. In conclusion, TFC and BLFC may prevent and alleviate neuronal cell death in the hippocampal CA1 region and neurological symptoms and poststroke hyperglycemia in gerbils with artery occlusion. This might be associated with increased isoflavonoid aglycones.

Acute ischemic stroke patients with diabetes should not be excluded from intravenous thrombolysis

The benefit of intravenous thrombolysis (IVT) has been questioned for patients with diabetes mellitus (DM) in cases of acute ischemic stroke (IS). Our objective was to analyze the differences in outcome according to prior diagnosis of DM and the use or not of IVT. Observational study with inclusion of consecutive IS patients admitted to an stroke unit. Demographic data, vascular risk factors, comorbidity, stroke severity and 3-month follow-up outcome (modified Rankin Scale) were compared according to prior diagnosis of DM and the use or not of IVT. A total of 1,139 IS patients were admitted; 283 (24.8%) patients had a diagnosis of DM, and 261 were IVT treated (23.2% of the group without DM and 21.9% of the DM group). The IVT-treated patients with DM were older, had more comorbidities and had higher glucose levels on admission than those without DM and than IVT-treated patients. No significant differences in stroke severity, hemorrhagic transformation, in-hospital mortality or outcome at 3 months were found. The logistic regression analysis showed that stroke severity was associated with a higher risk of a poor outcome in IVT-treated patients, with no significant effect from DM after adjustment for confounders. Moreover, IVT was independently associated with a lower risk of poor outcome in DM patients (OR 0.49; 95% CI 0.31-0.76; P = .002). DM patients should not be excluded from IVT, because DM is not associated with a poor outcome after IVT and this treatment is clearly beneficial for DM patients as compared with DM patients not treated with IVT.

Hyperglycemia, acute ischemic stroke, and thrombolytic therapy

Ischemic stroke is a leading cause of disability and is considered now the fourth leading cause of death. Many clinical trials have shown that stroke patients with acute elevation in blood glucose at onset of stroke suffer worse functional outcomes, longer in-hospital stay, and higher mortality rates. The only therapeutic hope for these patients is the rapid restoration of blood flow to the ischemic tissue through intravenous administration of the only currently proven effective therapy, tissue plasminogen activator (tPA). However, even this option is associated with the increased risk of intracerebral hemorrhage. Nonetheless, the underlying mechanisms through which hyperglycemia (HG) and tPA worsen the neurovascular injury after stroke are not fully understood. Accordingly, this review summarizes the latest updates and recommendations about the management of HG and coadministration of tPA in a clinical setting while focusing more on the various experimental models studying (1) the effect of HG on stroke outcomes, (2) the potential mechanisms involved in worsening the neurovascular injury, (3) the different therapeutic strategies employed to ameliorate the injury, and finally, (4) the interaction between HG and tPA. Developing therapeutic strategies to reduce the hemorrhage risk with tPA in hyperglycemic setting is of great clinical importance. This can best be achieved by conducting robust preclinical studies evaluating the interaction between tPA and other therapeutics in order to develop potential therapeutic strategies with high translational impact.

Effects of treadmill training on limb motor function and acetylcholinesterase activity in rats with stroke

[Purpose] In the present study, we investigated the effects of treadmill training on limb motor function and acetylcholinesterase activity following focal cerebral ischemia injury. [Methods] Focal cerebral ischemia was examined in adult male Sprague-Dawley rats by using a middle cerebral artery occlusion model. Rats were randomly divided into 3 groups. Group I included untreated normal rats (n=12), Group II included untreated rats with focal cerebral ischemia (n=12), and Group III included rats that performed treadmill exercise (20 m/min) training after focal cerebral ischemia (n=12). We determined the limb placement test score for each rat on days 1,7, 14, and 21; acetylcholinesterase activity in the hippocampus was examined at the end of the experiment. [Results] We observed that the motor behavior index improved in the treadmill group, and hippocampal acetylcholinesterase activity was decreased. [Conclusion] These results indicated that treadmill training after focal cerebral ischemia exerts a neuroprotective effects against ischemic brain injury by improving motor performance and decreasing the levels of acetylcholinesterase activity. Furthermore, these results suggest that treadmill training at an appropriate intensity is critical for post-stroke rehabilitation.

Predicting clinical outcomes and response to thrombolysis in acute stroke patients with diabetes

OBJECTIVE

Few tools are available to evaluate clinical outcomes and response to thrombolysis (tPA) in stroke patients with diabetes. We explored how the iScore (www.sorcan.ca/iscore), a validated risk score, predicts clinical outcomes in stroke patients with and without diabetes.

RESEARCH DESIGN AND METHODS

We applied the iScore to stroke patients presenting to stroke centers participating in the Registry of the Canadian Stroke Network. Main outcomes included favorable outcome, defined as a modified Rankin scale (mRS) 0-2 at discharge, and intracerebral hemorrhage (ICH) after tPA.

RESULTS

Among 12,686 patients with an acute ischemic stroke, 3,228 (25.5%) had diabetes. Among patients receiving tPA (n = 1,689), those with diabetes had a lower rate of a favorable outcome compared with their counterparts (24.3 vs. 31.1%; RR 0.90 [95% CI 0.82-0.98]). The risk of ICH was not significantly different in patients with or without diabetes (for any type 12.6 vs. 12.5%, RR 1.01 [0.72-1.40]; for symptomatic ICH 7.5 vs. 6.8%, RR 1.11 [0.70-1.72]). The regression analysis revealed a decline in the probability of a favorable outcome after tPA with increments in the iScore (P value for iScore × tPA interaction <0.001). There was no difference in the response to tPA predicted by the iScore between stroke patients with and without diabetes (P value = 0.07).

CONCLUSIONS

Stroke patients with diabetes have poorer outcomes compared with patients without diabetes, which is not explained by ICH. The iScore similarly predicts response to tPA between stroke patients with and without diabetes.

Tumor necrosis factor-induced cerebral insulin resistance in Alzheimer's disease links numerous treatment rationales

The evident limitations of the amyloid theory of the pathogenesis of Alzheimer's disease are increasingly putting alternatives in the spotlight. We argue here that a number of independently developing approaches to therapy-including specific and nonspecific anti-tumor necrosis factor (TNF) agents, apolipoprotein E mimetics, leptin, intranasal insulin, the glucagon-like peptide-1 mimetics and glycogen synthase kinase-3 (GSK-3) antagonists-are all part of an interlocking chain of events. All these approaches inform us that inflammation and thence cerebral insulin resistance constitute the pathway on which to focus for a successful clinical outcome in treating this disease. The key link in this chain presently absent is a recognition by Alzheimer's research community of the long-neglected history of TNF induction of insulin resistance. When this is incorporated into the bigger picture, it becomes evident that the interventions we discuss are not competing alternatives but equally valid approaches to correcting different parts of the same pathway to Alzheimer's disease. These treatments can be expected to be at least additive, and conceivably synergistic, in effect. Thus the inflammation, insulin resistance, GSK-3, and mitochondrial dysfunction hypotheses are not opposing ideas but stages of the same fundamental, overarching, pathway of Alzheimer's disease pathogenesis. The insight this provides into progenitor cells, including those involved in adult neurogenesis, is a key part of this approach. This pathway also has therapeutic implications for other circumstances in which brain TNF is pathologically increased, such as stroke, traumatic brain injury, and the infectious disease encephalopathies.