Stroke prevention in diabetes and obesity

Mechanistic correlation of molecular pathways in obesity-mediated stroke pathogenesis

Obesity, a prominent risk factor for the development of heart attacks and several cardiovascular ailments. Obesity ranks as the second most significant avoidable contributor to mortality, whereas stroke stands as the second leading cause of death on a global scale. While changes in lifestyle have been demonstrated to have significant impacts on weight management, the long-term weight loss remains challenging, and the global prevalence of obesity continues to rise. The pathophysiology of obesity has been extensively studied during the last few decades, and an increasing number of signal transduction pathways have been linked to obesity preclinically. This review is focused on signaling pathways, and their respective functions in regulating the consumption of fatty food as well as accumulation of adipose tissue, and the resulting morphological and cognitive changes in the brain of individuals with obesity. We have also emphasized the recent progress in the mechanisms behind the emergence of obesity, as elucidated by both experimental and clinical investigations. The mounting understanding of signaling transduction may shed light on the future course of obesity research as we move into a new era of precision medicine.

Obesity in acute ischaemic stroke patients treated with intravenous thrombolysis therapy

OBJECTIVES

This article aimed to analyze the relationship between obesity and the efficacy of acute ischaemic stroke patients treated with IVT.

BACKGROUND

Stroke causes morbidity and mortality in large numbers of individuals annually. Intravenous thrombolysis (IVT)with recombinant tissue plasminogen activator (r-tPA) is currently the only approved by the FDA for treatment of acute ischaemic stroke. Researchers have focused on studying the mechanisms associated with ischaemic stroke. Obesity is an established vascular risk factor with increasing prevalence and a huge impact on public health worldwide. It is an independent predictor for ischaemic stroke with a 4% risk increase for each unit augmentation in body mass index (BMI). Therefore, obese patients will constitute an increasing subgroup of candidates for IVT. However, its impact on prognosis in acute ischaemic stroke patients with intravenous thrombolysis did not reach a consensus conclusion.

METHODS

Systematic literature search of PUBMED databases published before August 2020, was performed to identify studies addressing the role of obesity in acute ischaemic stroke patients treated with IVT. Studies included randomized clinical trials, observational studies, guideline statements, and review articles.

CONCLUSIONS

Obesity may be related to long-term prognosis of large group of AIS patients treated with IVT. It depends on the scale of clinical study samples, follow-up time, and evaluation criteria.

Prevalence of dyslipidemia associated with complications in diabetic patients: a nationwide study in Thailand

Background

Dyslipidemia is an important modifiable risk factor for cardiovascular disease. It is diagnosed by the presence of an abnormal lipid profile, primarily with elevated levels of plasma cholesterol, triglyceride, or both, or reduced levels of high-density lipoprotein cholesterol. However, some studies have reported increased risk of ischemic stroke with elevated low-density lipoprotein cholesterol (LDL-C) levels and increased risk of cardiovascular mortality independent of LDL-C levels in type 2 diabetes mellitus (T2DM) patients.

Methods

In this cross-sectional study, data were included for Thai adults with diabetes from the Diabetes Mellitus/ Hypertension (DM/HT) study, 2010–2014 (data was collected by the Medical Research Network of the Consortium of Thai Medical Schools). The target population comprised T2DM patients who were treated at a hospital for more than 12 months. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated to determine factors associated with dyslipidemia.

Results

In total, 140,557 participants (average age, 60 years) were enrolled, with a dyslipidemia prevalence of 88.9% in the cohort. The factors associated with dyslipidemia included female sex (aOR: 1.47, 95% CI: 1.38–1.56); age < 50 years (aOR: 1.16, 95% CI: 1.10–1.22); waist circumference ≥ 90 cm in males and ≥ 80 cm in females (aOR: 1.23, 95% CI: 1.16–1.31); treatment at a primary care unit (aOR: 1.28, 95% CI: 1.23–1.33); and a history of unknown stroke (aOR: 1.10, 95% CI: 1.02–1.19), coronary revascularization (aOR: 0.85, 95% CI: 0.79–0.91), diabetic nephropathy (aOR: 1.06, 95% CI: 1.01–1.12), or renal insufficiency (aOR: 1.08, 95% CI: 1.02–1.13).

Conclusions

Dyslipidemia is prevalent among Thai T2DMpatients and is associated with gender; age; obesity; central obesity; treatment at a primary care unit; and a history of unknown stroke, coronary revascularization, diabetic nephropathy, and renal insufficiency. Our study results will help increase the awareness of healthcare providers regarding dyslipidemia in diabetic patients. To reduce cardiovascular risk, healthcare professionals should provide regular follow-up and proper advice and ensure primary prevention of vascular complications. Improved education and increased self-awareness regarding the need to change behaviors and regular intake of medication would help decrease dyslipidemia prevalence among diabetic patients.

Association of PAI-1 4G/5G Polymorphism with Ischemic Stroke in Chinese Patients with Type 2 Diabetes Mellitus

BACKGROUND/AIM

To investigate the association of the genetic polymorphisms of the plasminogen activator inhibitor type 1 (PAI-1) gene with the risk of ischemic stroke (IS) in subjects with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

Using a case-control study design, 175 individuals with T2D and IS were enrolled in the case group and 125 patients with T2D without IS were enrolled as controls. The clinical characteristics of the groups were compared, and genotypes were determined by direct DNA sequencing.

RESULTS

Male and hypertensive subjects were higher in the IS group (p = 0.002 and 0.014, respectively). High-density lipoprotein (HDL) and apolipoprotein A1 (APOA1) were lower in the IS group (p = 0.011 and 0.025, respectively); hemoglobin A1c (HbA1c), total homocysteine (tHcy), and FT4 levels were higher in the IS group (p = 0.022, 0.003, and 0.008, respectively). The 4G/4G, 4G/5G, and 5G/5G genotype frequencies were 40.0%, 46.4%, and 13.6% in the control group versus 31.4%, 52.0% and 16.6% in the IS group, respectively. Hypertension (odds ratio [OR] = 1.953, p = 0.020), tHcy (OR = 1.059, p = 0.029), thyroid-stimulating hormone (OR = 0.876, p = 0.039), and the PAI-1 genotype dominant allele model (OR = 1.748, p = 0.047) were associated with IS by multivariate analysis.

CONCLUSION

The PAI-1 genotype dominant allele model was a risk factor for IS in patients with T2DM of Jinan, China.

Is diabetes a marker of higher risk after carotid revascularization? Experience from a single centre

PURPOSE

This single centre study investigates the influence of diabetes mellitus on outcomes following carotid artery endarterectomy or stenting.

METHODS

In total, 752 carotid revascularizations (58.2% carotid artery stenting and 41.8% carotid endarterectomy) were performed in 221 (29.4%) patients with diabetes and 532 (70.6%) patients without diabetes. The study outcomes were death, disabling and non-disabling stroke, transient ischaemic attack and restenosis within 36 months after the procedure.

RESULTS

Patients with diabetes had higher periprocedural risk of any stroke or death (3.6% diabetes vs 0.6% no diabetes; p < 0.05), transient ischaemic attack (1.8% diabetes vs 0.2% no diabetes; p > 0.05) and restenosis (2.7% diabetes vs 0.6% no diabetes; p < 0.05). During long-term follow-up, there were no significant differences in Kaplan-Meier estimates of freedom from death, any stroke and transient ischaemic attack, between people with and without diabetes for each carotid artery stenting and carotid endarterectomy subgroup. Patients with diabetes showed higher rates of restenosis during follow-up than patients without diabetes (36-months estimate risk of restenosis: 21.2% diabetes vs 12.5% no diabetes; p < 0.05).

CONCLUSION

The presence of diabetes was associated with increased periprocedural risk, but no further additional risk emerged during longer term follow-up. Restenosis rates were higher among patients with diabetes.

Acute effects of hyperinsulinemia and hyperglycemia on vascular inflammatory biomarkers and endothelial function in overweight and obese humans

We investigated the separate and combined effects of hyperglycemia and hyperinsulinemia on markers of endothelial function, proinflammatory and proatherothrombotic responses in overweight/obese nondiabetic humans. Twenty-two individuals (13 F/9 M, BMI 30.1 ± 4.1 kg/m(2)) were studied during four randomized, single-blind protocols. The pancreatic clamp technique was combined with 4-h glucose clamps consisting of either 1) euinsulinemia-euglycemia, 2) euinsulinemia-hyperglycemia, 3) hyperinsulinemia-hyperglycemia, or 4) hyperinsulinemia-euglycemia. Insulin levels were higher (998 ± 66 vs. 194 ± 22 pmol/l) during hyperinsulinemia compared with euinsulinemia. Glucose levels were 11.1 mmol/l during hyperinsulinemia compared with 5.1 ± 0.1 mmol/l during euglycemia. VCAM, ICAM, P-selectin, E-selectin, IL-6, adiponectin, and PAI-1 responses were all increased (P < 0.01-0.0001), and endothelial function was decreased (P < 0.0005) during euinsulinemia-hyperglycemia compared with other protocols. Hyperinsulinemia in the presence of hyperglycemia prevented the increase in proinflammatory and proatherothrombotic markers while also normalizing vascular endothelial function. We conclude that 4 h of moderate hyperglycemia can result in increases of proinflammatory markers (ICAM, VCAM, IL-6, E-selectin), platelet activation (P-selectin), reduced fibrinolytic balance (increased PAI-1), and disordered endothelial function in a group of obese and overweight individuals. Hyperinsulinemia prevents the actions of moderate hyperglycemia to reduce endothelial function and increase proinflammatory and proatherothrombotic markers.

Systemic immune activation shapes stroke outcome

Stroke is a major cause of morbidity and mortality, and activation of the immune system can impact on stroke outcome. Although the majority of research has focused on the role of the immune system after stroke there is increasing evidence to suggest that inflammation and immune activation prior to brain injury can influence stroke risk and outcome. With the high prevalence of co-morbidities in the Western world such as obesity, hypertension and diabetes, pre-existing chronic 'low-grade' systemic inflammation has become a customary characteristic of stroke pathophysiology that needs to be considered in the search for new therapies. The importance of the immune system in stroke has been demonstrated in a number of ways, both experimentally and in the clinical setting. This review will focus on the effect of immune activation arising from systemic inflammatory conditions and infection, how it affects the incidence and outcomes of stroke, and the possible underlying mechanisms involved. This article is part of a Special Issue entitled 'Neuroinflammation in neurodegeneration and neurodysfunction'.

An update on markers of carotid atherosclerosis in patients with Type 2 diabetes

Carotid atherosclerosis constitutes an important cause of ischemic brain attack and stroke, accounting for up to 40% of cases of ischemic cerebrovascular disease. Type 2 diabetes mellitus is an independent risk factor for stroke and its recurrence. Thus, identifying diabetic patients who are at high risk of developing stroke is of great clinical importance. Noninvasive measurements of surrogate markers of atherosclerosis, such as novel serum biomarkers, can be helpful in detecting subclinical carotid disease, especially among individuals at the highest cardio-/cerebro-vascular risk. Previous studies have proposed an expanding body of serum biomarkers, such as C-reactive protein, fibrinogen, adipokines, cytokines and growth factors, as novel indicators of carotid atherosclerosis development that predict carotid-related clinical outcomes. Furthermore, those biomarkers are expected to assess the efficacy of both pharmaceutical and interventional strategies. Accordingly, it is increasingly clear that measuring biomarkers may improve the definition of cerebrovascular risk profile in patients with Type 2 diabetes mellitus.

Dietary restriction and brain health

The benefits of dietary restriction (DR) on health and aging prevention have been well recognized. Recent studies suggest that DR may enhance brain functions including learning and memory, synaptic plasticity, and neurogenesis, all of which are associated with brain health. Under the stress stimulated by DR, a favorable environment is established for facilitating neuronal plasticity, enhancing cognitive function, stimulating neurogenesis and regulating inflammatory response. DR-induced expressions of factors such as heat shock proteins (HSPs), neurotrophic factors, and Sirtuin1 (SIRT1) are responsible for the effect of DR on the brain. Due to the difficulty in practising long-term DR in human, the potential mimics of DR are also discussed.

Inflammation as a therapeutic target in heart failure? A scientific statement from the Translational Research Committee of the Heart Failure Association of the European Society of Cardiology

The increasing prevalence of heart failure poses enormous challenges for health care systems worldwide. Despite effective medical interventions that target neurohumoral activation, mortality and morbidity remain substantial. Evidence for inflammatory activation as an important pathway in disease progression in chronic heart failure has emerged in the last two decades. However, clinical trials of 'anti-inflammatory' therapies (such as anti-tumor necrosis factor-alpha approaches) have to date failed to show benefit in heart failure patients. The Heart Failure Association of the European Society of Cardiology recently organized an expert workshop to address the issue of inflammation in heart failure from a basic science, translational and clinical perspective, and to assess whether specific inflammatory pathways may yet serve as novel therapeutic targets for this condition. This consensus document represents the outcome of the workshop and defines key research questions that still need to be addressed as well as considering the requirements for future clinical trials in this area.

Sulfonylureas improve outcome in patients with type 2 diabetes and acute ischemic stroke

BACKGROUND AND PURPOSE

The sulfonylurea receptor 1-regulated NC(Ca-ATP) channel is upregulated in rodent models of stroke with block of the channel by the sulfonylurea, glibenclamide (glyburide), significantly reducing mortality, cerebral edema, and infarct volume. We hypothesized that patients with type 2 diabetes mellitus taking sulfonylurea agents both at the time of stroke and during hospitalization would have superior outcomes.

METHODS

We reviewed medical records of patients with diabetes mellitus hospitalized within 24 hours of onset of acute ischemic stroke in the Neurology Clinic, Charité Hospital, Berlin, Germany, during 1994 to 2000. After exclusions, the cohort comprised 33 patients taking a sulfonylurea at admission through discharge (treatment group) and 28 patients not on a sulfonylurea (control group). The primary outcome was a decrease in National Institutes of Health Stroke Scale of 4 points or more from admission to discharge or a discharge National Institutes of Health Stroke Scale score of 0. The secondary outcome was a discharge modified Rankin Scale score < or =2.

RESULTS

No significant differences, other than stroke subtype, were observed among baseline variables between control and treatment groups. The primary outcome was reached by 36.4% of patients in the treatment group and 7.1% in the control group (P=0.007). The secondary outcome was reached by 81.8% versus 57.1% (P=0.035). Subgroup analyses showed that improvements occurred only in patients with nonlacunar strokes and were independent of gender, previous transient ischemic attack, and blood glucose levels.

CONCLUSIONS

Sulfonylureas may be beneficial for patients with diabetes mellitus with acute ischemic stroke. Further investigation of similar cohorts and a prospective randomized trial are recommended to confirm the present observations.