Albuminuria, but not metabolic syndrome, is a significant predictor of stroke recurrence in ischemic stroke

Kidney disease and stroke: epidemiology and potential mechanisms of susceptibility

Patients with chronic kidney disease (CKD) have an increased risk of both ischaemic and haemorrhagic stroke compared with the general population. Both acute and chronic kidney impairment are independently associated with poor outcome after the onset of a stroke, after adjustment for confounders. End-stage kidney disease (ESKD) is associated with a 7- and 9-fold increased incidence of both ischaemic and haemorrhagic strokes, respectively, poorer neurological outcome and a 3-fold higher mortality. Acute kidney injury (AKI) occurs in 12% of patients with stroke and is associated with a 4-fold increased mortality and unfavourable functional outcome. CKD patients seem to have less access to revascularisation techniques like thrombolysis and thrombectomy despite their poorer prognosis. Even if CKD patients could benefit from these specific treatments in acute ischaemic stroke, their prognosis remains poor. After thrombolysis, CKD is associated with a 40% increased risk of intracerebral haemorrhage (ICH), a 20% increase in mortality and poorer functional neurological outcomes. After thrombectomy, CKD is not associated with ICH but is still associated with increased mortality, and AKI with unfavourable outcome and mortality. The beneficial impact of gliflozins on the prevention of stroke is still uncertain. Non-traditional risk factors of stroke, like uraemic toxins, can lead to chronic cerebrovascular disease predisposing to stroke in CKD, notably through an increase in the blood-brain barrier permeability and impaired coagulation and thrombosis mechanisms. Preclinical and clinical studies are needed to specifically assess the impact of these non-traditional risk factors on stroke incidence and outcomes, aiming to optimize and identify potential therapeutic targets.

Diabetes As an Independent Risk Factor for Stroke Recurrence in Ischemic Stroke Patients: An Updated Meta-Analysis

INTRODUCTION

Stroke and its recurrence and diabetes will increase in incidence as the population ages globally. This study explores the relationship between diabetes and stroke recurrence to understand if diabetes is an independent predictor for stroke recurrence in ischemic stroke (IS) patients.

METHODS

We conducted a systematic review and meta-analysis of studies on the effect of diabetes on stroke recurrence among patients with IS. We searched population-based studies published before 15th February 2021 in PubMed and EMBASE following PRISMA guidelines. Random-effects estimates of the pooled hazard ratio (HR) and 95% confidence intervals (CIs) of each study were generated. A funnel plot and an Egger test were performed to evaluate publication bias. All statistical analyses were conducted in the R software 4.0.1 and Stata 16.0.

RESULTS

The search identified 3,121 citations, of which 27 studies met inclusion criteria. Diabetes was associated with a significant risk of stroke recurrence in all IS patients (pooled HR, 1.50; 95% CI: 1.36-1.65; I2 = 61.0%). Similar results were found in lacunar stroke patients with diabetes (pooled HR, 1.65; 95% CI: 1.41-1.92; I2 = 22.0%). Moreover, we found that the risk of recurrent IS among patients of IS with diabetes was higher than that in those without diabetes (pooled HR, 1.53; 95% CI: 1.30-1.81; I2 = 74.0%).

CONCLUSION

Diabetes is an independent risk factor for stroke recurrence among patients with IS.

Association of Metabolic Syndrome and Its Components With Risk of Stroke Recurrence and Mortality: A Meta-analysis

OBJECTIVE

Because metabolic syndrome is a significant risk factor for cardio-cerebrovascular diseases and the relationship between metabolic syndrome (including its components) and the prognosis of stroke is controversial, this study was conducted to evaluate whether metabolic syndrome is associated with a high recurrence and mortality of stroke.

METHODS

This study was registered in the PROSPERO database (CRD42020177118). We searched for relevant observational cohort studies published from inception to April 23, 2020, using PubMed, Embase, and the Cochrane Library. Effect estimates with 95% confidence intervals (CIs) were pooled using the random-effects model. The primary and secondary outcomes were stroke recurrence and all-cause mortality, respectively. Leave-one-out sensitivity analyses and nonparametric trim-and-fill method were used to identify the stability of the results.

RESULTS

Thirteen cohort studies comprising 59,919 participants >60 years of age were included for analysis. Overall, metabolic syndrome was significantly associated with stroke recurrence (relative risk [RR] 1.46, 95% CI 1.07-1.97, p = 0.02). Among the metabolic syndrome components, low levels of high-density lipoprotein cholesterol (HDL-C) (RR 1.32, 95% CI 1.11-1.57, p = 0.002) and ≥2 metabolic syndrome components (RR 1.68, 95% CI 1.44-1.94, p < 0.001) significantly predicted stroke recurrence, whereas elevated triglycerides, elevated waist circumference, hyperglycemia, and hypertension failed to account for risk factors for stroke recurrence. Moreover, metabolic syndrome, not its components, was significantly associated with all-cause mortality (RR 1.27, 95% CI 1.18-1.36, p < 0.001). The stability of these results was further confirmed by the leave-one-out sensitivity analyses and nonparametric trim-and-fill method.

CONCLUSIONS

The present study indicates that metabolic syndrome and some of its components (low HDL-C and number of metabolic syndrome components) seem to be risk factors for stroke recurrence. Although metabolic syndrome is also associated with all-cause mortality, the role of its components in predicting all-cause mortality deserves further study.

Cerebro-renal interaction and stroke

Stroke is an event causing a disturbance in cerebral function leading to death and disability worldwide. Both acute kidney injury and chronic kidney disease (CKD) are associated with an increased risk of stroke and cerebrovascular events. The underlying mechanistic approach between impaired renal function and stroke is limitedly explored and has attracted researchers to learn more for developing therapeutic intervention. Common risk factors such as hypertension, hyperphosphatemia, atrial fibrillation, arteriosclerosis, hyperhomocysteinemia, blood-brain barrier disruption, inflammation, etc. are observed in the general population, but are high in renal failure patients. Also, risk factors like bone mineral metabolism, uremic toxins, and anemia, along with the process of dialysis in CKD patients, eventually increases the risk of stroke. Therefore, early detection of risks associated with stroke in CKD is imperative, which may decrease the mortality associated with it. This review highlights mechanisms by which kidney dysfunction can lead to cerebrovascular events and increase the risk of stroke in renal impairment.

Microvascular complications of diabetes worsen long-term functional outcomes after acute ischemic stroke

Objective

This study was performed to evaluate the potential predictors of poor outcomes associated with diabetes-specific microvascular pathologies and to analyze their influence on clinical outcomes by adjusting for other well-known prognostic factors in patients with acute ischemic stroke.

Methods

We analyzed 1389 consecutive adult patients with acute ischemic stroke and explored the relationship among clinical characteristics, laboratory measurements, imaging findings, and 6-month functional outcomes.

Results

The final study population comprised 216 patients with both acute ischemic stroke and diabetes mellitus who were followed up for 6 months. A multiple logistic regression analysis of poor outcomes revealed the following independent predictors: leukoaraiosis severity [odds ratio (OR), 7.38; 95% confidence interval (CI), 1.40–38.86, per 1-point increase), diabetic nephropathy (OR, 10.66; 95% CI, 1.10–103.43), and the admission National Institutes of Health stroke scale score (OR, 2.58; 95% CI, 1.36–4.92 per 1-point increase). In this model, admission hyperglycemia and intracerebral hemorrhagic transformation were not independent prognostic predictors.

Conclusion

Microvascular complications (such as nephropathy) caused by diabetes mellitus predict an unfavorable clinical outcome after acute ischemic stroke. Diabetic nephropathy may partly affect post-stroke prognosis by means of exacerbating leukoaraiosis.

Sex differences in ischaemic stroke: potential cellular mechanisms

Stroke remains a leading cause of mortality and disability worldwide. More women than men have strokes each year, in part because women live longer. Women have poorer functional outcomes, are more likely to need nursing home care and have higher rates of recurrent stroke compared with men. Despite continued advancements in primary prevention, innovative acute therapies and ongoing developments in neurorehabilitation, stroke incidence and mortality continue to increase due to the aging of the U.S.

POPULATION

Sex chromosomes (XX compared with XY), sex hormones (oestrogen and androgen), epigenetic regulation and environmental factors all contribute to sex differences. Ischaemic sensitivity varies over the lifespan, with females having an "ischaemia resistant" phenotype that wanes after menopause, which has recently been modelled in the laboratory. Pharmacological therapies for acute ischaemic stroke are limited. The only pharmacological treatment for stroke approved by the Food and Drug Administration (FDA) is tissue plasminogen activator (tPA), which must be used within hours of stroke onset and has a number of contraindications. Pre-clinical studies have identified a number of potentially efficacious neuroprotective agents; however, nothing has been effectively translated into therapy in clinical practice. This may be due, in part, to the overwhelming use of young male rodents in pre-clinical research, as well as lack of sex-specific design and analysis in clinical trials. The review will summarize the current clinical evidence for sex differences in ischaemic stroke, and will discuss sex differences in the cellular mechanisms of acute ischaemic injury, highlighting cell death and immune/inflammatory pathways that may contribute to these clinical differences.

High Levels of Soluble Lectin-Like Oxidized Low-Density Lipoprotein Receptor-1 in Acute Stroke: An Age- and Sex-Matched Cross-Sectional Study

AIM

Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is known to be a key molecule in the pathogenesis of atherosclerosis. Although high levels of serum soluble LOX-1 (sLOX-1) were demonstrated in patients with acute coronary syndrome, there are no reports about acute stroke patients. The aim of the present study was to evaluate the levels of sLOX-1 in acute stroke patients according to different stroke subtypes.

METHODS

We enrolled a total of 377 patients with a stroke (men/women: 251/126; age: 40-79 years), 250 with ischemic stroke and 127 with intracerebral hemorrhage (ICH). Patients were admitted to our hospital within 3 days after the onset of stroke. As controls, we randomly selected age- and sex-matched subjects without a past history of cardiovascular disease according to stroke subtype from the community-based cohort of the Suita study. Serum LOX-1 levels were compared between stroke patients and healthy controls according to stroke subtype.

RESULTS

Median values of serum sLOX-1 in stroke patients were significantly higher than those in controls (526 vs. 486 ng/L in ischemic stroke and 720 vs. 513 ng/L in ICH, respectively). Among subtypes of ischemic stroke, median sLOX-1 levels in atherothrombotic brain infarction (641 ng/L) only were significantly higher than those in controls (496 ng/L). Ischemic stroke [odds ratio (OR), 3.80; 95% confidence interval (CI), 1.86-7.74] and ICH (OR, 5.97; 95% CI, 2.13-16.77) were independently associated with high levels of sLOX-1 by multivariate logistic regression analysis.

CONCLUSIONS

Higher levels of sLOX-1 were observed in patients with acute stoke than in controls. High levels of sLOX-1 can be useful as biomarker for acute stroke.

Metabolic Syndrome, Its Components, and Diabetes on 5-Year Risk of Recurrent Stroke among Mild-to-Moderate Ischemic Stroke Survivors: A Multiclinic Registry Study

OBJECTIVES

The pieces of evidence regarding whether metabolic syndrome (MetS) is a better predictor than its individual components, especially diabetes, for recurrent stroke are limited. This study aimed to examine these associations.

METHODS

A total of 1087 ischemic stroke patients were recruited consecutively from 2003 to 2004. They were followed up until the end of 2008. Baseline clinical and laboratory characteristics and new stroke event during follow-up were recorded. MetS was defined by the definition issued by the Chinese Medical Association/Chinese Diabetes Society.

RESULTS

One hundred forty-three new stroke cases were recorded. After adjusting for baseline age, gender, education, marriage status, subtype stroke, length of index stroke to baseline assessment, history of cardiac diseases, smoking status, drinking status, clinics, aspirin treatment, and fibrinogen by Cox regression models, the risk of recurrent stroke was 43% higher in MetS patients than in non-MetS patients (hazard ratio [HR] = 1.43, 95% confidence interval [CI]: 1.01-2.01). The strength of this association is weaker than MetS individual components such as elevated glycemia (adjusted HR = 1.78, 95% CI: 1.26-2.52), elevated blood pressure (adjusted HR = 1.91, 95% CI: 1.11-3.30), or low high-density lipoprotein cholesterol (adjusted HR = 1.57, 95% CI: 1.08-2.51). Compared with the group with neither MetS nor diabetes, the adjusted risk of recurrent stroke was highest in the group with diabetes (HR = 2.77, 95% CI: 1.66-4.63), followed by those with both MetS and diabetes (HR = 1.91, 95% CI: 1.25-2.94). The risk of recurrent stroke in patients with MetS in the absence of diabetes was similar to those with neither.

CONCLUSION

MetS is not superior to its individual components in predicting future recurrent stroke in patients who experience mild-to-moderate ischemic stroke.

Guidelines for the prevention of stroke in patients with stroke and transient ischemic attack: a guideline for healthcare professionals from the American Heart Association/American Stroke Association

The aim of this updated guideline is to provide comprehensive and timely evidence-based recommendations on the prevention of future stroke among survivors of ischemic stroke or transient ischemic attack. The guideline is addressed to all clinicians who manage secondary prevention for these patients. Evidence-based recommendations are provided for control of risk factors, intervention for vascular obstruction, antithrombotic therapy for cardioembolism, and antiplatelet therapy for noncardioembolic stroke. Recommendations are also provided for the prevention of recurrent stroke in a variety of specific circumstances, including aortic arch atherosclerosis, arterial dissection, patent foramen ovale, hyperhomocysteinemia, hypercoagulable states, antiphospholipid antibody syndrome, sickle cell disease, cerebral venous sinus thrombosis, and pregnancy. Special sections address use of antithrombotic and anticoagulation therapy after an intracranial hemorrhage and implementation of guidelines.

Preserved acetazolamide reactivity in lacunar patients with severe white-matter lesions: 15O-labeled gas and H2O positron emission tomography studies

Limited evidence exists on the relationships between severity of white-matter lesions (WMLs) and cerebral hemodynamics in patients without major cerebral artery disease. To examine changes of cerebral blood flow (CBF), oxygen metabolism, and vascular reserve capacity associated with severity of WML in patients with lacunar stroke, we used a positron emission tomography (PET). Eighteen lacunar patients were divided into two groups according to the severity of WMLs, assessed by Fazekas classification; grades 0 to 1 as mild WML group and grades 2 to 3 as severe WML group. Rapid dual autoradiography was performed with (15)O-labeled gas-PET followed by (15)O-labeled water-PET with acetazolamide (ACZ) challenge. Compared with the mild WML group, the severe WML group showed lower CBF (20.6±4.4 versus 29.9±8.2 mL/100 g per minute, P=0.008), higher oxygen extraction fraction (OEF) (55.2±7.4 versus 46.7±5.3%, P=0.013), and lower cerebral metabolic rate of oxygen (CMRO(2)) (1.95±0.41 versus 2.44±0.42 mL/100 g per minute, P=0.025) in the centrum semiovale. There were no significant differences in the ACZ reactivity between the two groups (48.6±22.6% versus 42.5±17.2%, P=0.524). Lacunar patients with severe WMLs exhibited reduced CBF and CMRO(2), and increased OEF in the centrum semiovale. The ACZ reactivity was preserved in both patients with severe and mild WMLs in each site of the brain.

Impact of microalbuminuria on incident stroke: a meta-analysis

BACKGROUND AND PURPOSE

Microalbuminuria, a marker of both kidney disease and endothelial dysfunction, may be associated with global vascular risk, but the nature and magnitude of the link between microalbuminuria and incident stroke has not been clearly defined. The purpose of this study was to assess the consistency and strength of the association of microalbuminuria with risk of stroke in prospective studies using meta-analysis.

METHODS

We conducted a systematic search of electronic databases and bibliographies for studies reporting a multivariate-adjusted estimate, represented as relative risk with 95% CI, of the association between microalbuminuria and stroke risk. Studies were excluded if a majority of study participants had established kidney disease or pre-eclampsia. Estimates were combined using a random-effect model.

RESULTS

We identified 12 studies, with a total of 48 596 participants and 1263 stroke events. Overall, presence of microalbuminuria was associated with greater stroke risk (relative risk, 1.92; 95% CI, 1.61 to 2.28; P < 0.001) after adjustment for established cardiovascular risk factors. There was evidence of significant heterogeneity in the magnitude of the association across studies (P for heterogeneity < 0.001, I² = 68%), which was partially explained by differences in study population, microalbuminuria definition, and different microalbuminuria-related risk among stroke subtypes. However, in stratified analyses, microalbuminuria was associated with increased risk of subsequent stroke in all subgroups (general population, diabetics, those with known stroke).

CONCLUSIONS

Microalbuminuria is strongly and independently associated with incident stroke risk. Future studies should explore whether microalbuminuria is just a risk marker or a modifiable risk factor for stroke.