Obesity paradox and stroke outcomes according to stroke subtype: a propensity score-matched analysis

Obesity-induced blood-brain barrier dysfunction: phenotypes and mechanisms

Obesity, a burgeoning global health issue, is increasingly recognized for its detrimental effects on the central nervous system, particularly concerning the integrity of the blood-brain barrier (BBB). This manuscript delves into the intricate relationship between obesity and BBB dysfunction, elucidating the underlying phenotypes and molecular mechanisms. We commence with an overview of the BBB's critical role in maintaining cerebral homeostasis and the pathological alterations induced by obesity. By employing a comprehensive literature review, we examine the structural and functional modifications of the BBB in the context of obesity, including increased permeability, altered transport mechanisms, and inflammatory responses. The manuscript highlights how obesity-induced systemic inflammation and metabolic dysregulation contribute to BBB disruption, thereby predisposing individuals to various neurological disorders. We further explore the potential pathways, such as oxidative stress and endothelial cell dysfunction, that mediate these changes. Our discussion culminates in the summary of current findings and the identification of knowledge gaps, paving the way for future research directions. This review underscores the significance of understanding BBB dysfunction in obesity, not only for its implications in neurodegenerative diseases but also for developing targeted therapeutic strategies to mitigate these effects.

Adiposity and Functional Outcome After Ischemic Stroke: A Mendelian Randomization Study

BACKGROUND AND OBJECTIVES

To investigate the causal relationships of abdominal adiposity (waist-to-hip ratio [WHR]) and overall adiposity (body mass index [BMI]) with functional outcome after ischemic stroke using Mendelian randomization.

METHODS

Genetic instruments for WHR and BMI were obtained from the largest available genome-wide association studies meta-analysis of the Genetic Investigation of ANthropometric Traits consortium and the UK Biobank (N max = 806,834). Functional outcome after ischemic stroke was assessed using the modified Rankin Scale (mRS) score at 3-month after stroke onset, with mRS >2 (mRS 3-6) defined as an unfavorable functional outcome. Corresponding genetic estimates for an unfavorable functional outcome were extracted from the Genetics of Ischemic Stroke Functional Outcome network (N = 6,021). We applied a random-effects inverse variance weighted method as our main analysis.

RESULTS

Genetically predicted higher WHR (per 0.09 ratio units) was associated with unfavorable functional outcome after ischemic stroke (mRS 3-6, OR = 1.48; 95% CI = 1.03-2.13; p = 0.033). The results remained directionally consistent in sensitivity analyses. Conversely, genetically predicted BMI (per 4.8 kg/m2) was not associated with unfavorable functional outcome after ischemic stroke (OR = 1.01; 95% CI = 0.75-1.36; p = 0.937).

DISCUSSION

This study provides genetic evidence supporting the hypothesis that abdominal adiposity has a detrimental effect on functional recovery after ischemic stroke.

Association between internal carotid artery kinking and ischemic stroke: A population-based cross-sectional study

AIM

Evidence for an association between Internal carotid artery (ICA) kinking and ischemic stroke has been controversial. We aimed to examine the association between ICA tortuosity and risk of ischemic stroke and specific ischemic stroke subtypes (large artery atherosclerosis, LAA; small artery occlusion, SAO).

METHODS

A total of 419 outpatients were included in this cross-sectional study. ICA kinking was objectively assessed by head and neck computed tomography angiography (CTA). The risk of ischemic stroke for each patient was evaluated according to the Essen Stroke Risk Score (ESRS). Ischemic stroke subtypes (LAA and SAO) were measure with head magnetic resonance imaging (MRI).

RESULTS

The average age of patients was 59.1 years (SD = 13.25) and 264 (63.0 %) were males. The prevalence of ICA kinking in this sample was 31.5 % (132 out of 419). Individuals with ICA kinking was associated with 0.55-points increase in ESRS score than those without ICA kinking (95 % CI, 0.28-0.81, p < 0.001) among patients over 50 years. In addition, right ICA kinking or left ICA kinking were associated with 0.35-points (95 % CI, 0.08-0.63) and 0.49-points (95 % CI, 0.23-0.76) increase in ESRS score, respectively. For specific ischemic stroke subtypes, individuals with ICA kinking had a 10.34-fold increased risk of SAO compared to those without ICA kinking (95 % CI, 6.22-20.68). Individuals with right ICA kinking had a 4.51-fold risk of SAO than those without kinking (95 % CI, 2.64-7.71), and had an 8.86-fold risk of SAO than those without kinking in the left ICA kinking (95 % CI, 4.97-15.79).

CONCLUSION

Our findings support the role of ICA kinking on ischemic stroke. Early screening and proper treatment of carotid artery tortuosity could be a potential intervention strategy for the prevention of ischemic stroke later on.

Serum NT-proBNP level for predicting functional outcomes after acute ischemic stroke

N-terminus pro-brain natriuretic peptide (NT-proBNP) has been studied and recognized as a biomarker of cardiac thrombogenicity and stroke risk. However, the association between NT-proBNP and functional outcomes following acute ischemic stroke is still debated. This study aimed to investigate whether serum NT-proBNP level is associated with functional outcomes in acute ischemic stroke individuals. This prospective cohort study included patients diagnosed with acute ischemic stroke, and serum NT-proBNP levels were measured within 72 h. At 3 months, all patients were followed up for a modified Rankin Scale (mRS), and logistic regression models were used to evaluate the association of NT-proBNP on the primary outcome, in which a score of 3-6 was classified as an unfavorable functional outcome. Sixty-seven patients were enrolled in the study, and 23 (34.3%) patients were identified with an unfavorable functional outcome. Elevated serum NT-proBNP levels (> 100 pg/mL) were observed in 57 (85.1%) patients, and the Youden index demonstrated a cutpoint estimation of poor outcomes at 476 pg/mL with 74% sensitivity and 63% specificity. Multivariate regression analysis showed an elevation of NT-proBNP above the cutpoint level was an independent predictor for unfavorable functional outcomes, odds ratio 3.77, 95% confidence interval (1.04-13.62), P = 0.04. The present study demonstrated that elevated serum NT-proBNP levels were expected among acute ischemic stroke patients and represented the risk of unfavorable functional outcomes, suggesting that NT-proBNP might be a useful biomarker for predicting prognosis after ischemic stroke.

Effects of body mass index on the immune response within the first days after major stroke in humans

INTRODUCTION

Immunological alterations associated with increased susceptibility to infection are an essential aspect of stroke pathophysiology. Several immunological functions of adipose tissue are altered by obesity and are accompanied by chronic immune activation. The purpose of this study was to examine immune function (monocytes, granulocytes, cytokines) as a function of body mass index (BMI: 1st group: 25; 2nd group: 25 BMI 30; 3rd group: 30) and changes in body weight post stroke.

METHOD

Fat status was assessed using standardized weight measurements on days 1, 2, 3, 4, 5, and 7 after ischemic stroke in a cohort of 40 stroke patients and 16 control patients. Liver fat and visceral fat were assessed by MRI on day 1 or 2 [I] and on day 5 or 7 [II]. Leukocyte subpopulations in peripheral blood, cytokines, chemokines, and adipokine concentrations in sera were quantified. In a second cohort (stroke and control group, n = 17), multiple regression analysis was used to identify correlations between BMI and monocyte and granulocyte subpopulations.

RESULTS

Weight and fat loss occurred from the day of admission to day 1 after stroke without further reduction in the postischemic course. No significant changes in liver or visceral fat were observed between MRI I and MRI II. BMI was inversely associated with IL-6 levels, while proinflammatory cytokines such as eotaxin, IFN-β, IFN -γ and TNF-α were upregulated when BMI increased. The numbers of anti-inflammatory CD14+CD16+ monocytes and CD16+CD62L- granulocytes were reduced in patients with higher BMI values, while that of proinflammatory CD16dimCD62L+ granulocytes was increased.

CONCLUSION

A small weight loss in stroke patients was detectable. The data demonstrate a positive correlation between BMI and a proinflammatory poststroke immune response. This provides a potential link to how obesity may affect the clinical outcome of stroke patients.