Sex Differences In Stroke Research Articles

Sepsis after middle cerebral artery occlusion exacerbates peripheral oxidative stress in a sex-specific manner

Ischemic stroke occurs due a blockage in the blood flow to the brain, leading to damage to the nervous system. The prevalent morbidities resulting from stroke include post-stroke infection, as sepsis. Additionally, oxidative stress is recognized for inducing functional deficits in peripheral organs during sepsis. Therefore, sex differences in stroke exist and we aimed to investigate the peripheral oxidative stress caused by sepsis after stroke in male and female rats. Wistar rats (male and female) were divided into sham+sham, middle cerebral artery occlusion (MCAO) + sham, sham+ cecal ligation and perforation (CLP) and MCAO+CLP groups to males and female rats. Animals were subjected to MCAO or sham and after 7 days, were subjected to sepsis by CLP or sham. After 24 h, serum, total brain, lung, liver, heart, and spleen were collected. Brain edema, myeloperoxidase (MPO) activity, nitrite/nitrate (N/N) concentration, oxidative damage to lipids and proteins, and catalase activity were evaluated. Brain edema was observed only in male rats in MCAO+CLP group compared to MCAO+sham. Regarding MPO activity, an increase was verified in male in different organs and serum in MCAO+CLP group. For N/N levels, the increase was more pronounced in females submitted to MCAO+CLP. In general, to oxidative stress, an increase was only observed in animals exposed to MCAO+CLP, or with a greater increase in this group compared to the others. The findings provided the first indication that animals exposed to MCAO exhibit a heightened vulnerability to the harmful impacts of sepsis, as evidenced by brain edema and peripheral oxidative stress, and this susceptibility is dependent of sex.

Time-trends of sex differences in stroke risk in atrial fibrillation: Are female patients still at higher risk today? A nationwide cohort study

Abstract Background Female sex is associated with higher risk of stroke in patients with atrial fibrillation (AF), particularly in the presence of other stroke risk factors. This has implications for oral anticoagulant treatment (OAC) decision-making, based on points of the CHA2DS2-VASc score. However, stroke rates have declined over recent years, and management has evolved over time towards a holistic approach that may have diminished the sex differences in AF-related stroke. Purpose To examine the changes in stroke risk over time in relation to risk differences between males and females not treated with oral anticoagulants in a nationwide cohort study. Methods This was an observational cohort study including patients with a hospital diagnosis of AF between 2007 and 2021. Data were obtained from the Danish nationwide registries. We identified a cohort of adult patients who were not receiving OAC treatment for up to 30 days after their AF diagnosis. Patients were followed up for thromboembolic events within one year after the AF diagnosis. Survival analysis was applied to describe the yearly rate of events and to estimate the risk ratio for females vs males of thromboembolism according to baseline risk levels, i.e., the CHA2DS2-VA score level (leaving out the ‘Sc’ sex criterion). Results A total of 188,704 AF patients (median age 75 years (IQR: 64 to 84); 49.7% female) who did not receive OAC treatment were included. The risk of thromboembolism during the entire study period was overall higher in females (3.5% in males vs. 4.7% among females). The overall one-year thromboembolic risk declined over time from 4.9% between 1997-2000 to 3.3% between 2017-2020, with male-female risk differences less evident in recent years (Figure 1a). The relative risk of stroke diminished from 1.22 (95%CI 1.10-1.34) in years 1997-2000 to 1.02 (95%CI 0.85-1.19) in years 2017-2020 for patients with a CHA2DS2-VA score of ≥2 (Figure 1b). For patients with a score of <2, the relative risk was lowest between 2005-2008 (1.02 (95%CI 0.63-1.42)) and was 1.18 (95%CI 0.54-1.83) in the latest time period. Formal statistical test for time trends according to score level revealed non-significant results (p-value=0.10 for score 0-1; p-value=0.17 for score levels of ≥2). Conclusion The risk of stroke among patients with AF has been declining over the last two decades. The excess stroke risk observed among females relative to males has also diminished, most evident among AF patients with ≥2 prevalent stroke risk factors.

Predictors of functional outcome after stroke: Sex differences in older individuals.

Sex differences in stroke are well documented, with females being older at onset, with more severe strokes and worse outcomes than males. Females receive less comprehensive stroke unit treatment. Similarly, older individuals receive poorer quality care than younger ones. There is limited research on sex differences in factors that impact 3-month poststroke functional outcome in people older than 80 years. This register-based and cross-sectional study analyzed data from two stroke quality registers in Sweden from 2014 through 2019. The study included patients aged ≥80 with a diagnosis of ischemic or hemorrhagic stroke. Sociodemographic features, prestroke condition, stroke severity on admission (National Institutes of Health Stroke Scale [NIHSS]), stroke unit care, rehabilitation plans, and 3-month poststroke functional outcome measured with the modified Rankin Scale were analyzed. Ordinal regression analyses stratified by sex were conducted to assess sex differences in factors that impact poststroke functional outcome 3 months after the stroke. A total of 2245 patients were studied with the majority (59.2%) being females. Females experienced more severe strokes (NIHSS median 4 vs. 3, p = 0.01) and were older at stroke onset than males (87.0 vs. 85.4, p < 0.001). Females were also less independent prestroke (69.9% vs. 77.4%, p < 0.001) and a higher proportion of females lived alone (78.2% vs. 44.2%, p < 0.001). Males received intravenous thrombolysis more often than females (16.3% vs. 12.0%, p = 0.005). Regarding 3-month functional outcome, males benefited more from thrombolysis (odds ratio [OR] 0.52, 95% confidence interval [CI] 0.30-0.83), whereas females benefited more from thrombectomy (OR 0.40, 95% CI 0.20-0.71). Stroke care should be adapted to sex disparities in older individuals, while clinicians should be aware of these sex disparities. Further research could clarify the mechanisms behind these disparities and lead to a more personalized approach to stroke care of the older population.

Sex-Associated Metabolites and Incident Stroke, Incident Coronary Heart Disease, Hypertension, and Chronic Kidney Disease in the REGARDS Cohort.

Sex disparities exist in cardiometabolic diseases. Metabolomic profiling offers insight into disease mechanisms, as the metabolome is influenced by environmental and genetic factors. We identified metabolites associated with sex and determined if sex-associated metabolites are associated with incident stoke, incident coronary heart disease, prevalent hypertension, and prevalent chronic kidney disease. Targeted metabolomics was conducted for 357 metabolites in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) case-cohort substudy for incident stroke. Weighted logistic regression models were used to identify metabolites associated with sex in REGARDS. Sex-associated metabolites were replicated in the HyperGEN (Hypertension Genetic Epidemiology Network) and using the literature. Weighted Cox proportional hazard models were used to evaluate associations between metabolites and incident stroke. Cox proportional hazard models were used to evaluate associations between metabolites and incident coronary heart disease. Weighted logistic regression models were used to evaluate associations between metabolites and hypertension and chronic kidney disease. Fifty-one replicated metabolites were associated with sex. Higher levels of 6 phosphatidylethanolamines were associated with incident stroke. No metabolites were associated with incident coronary heart disease. Higher levels of uric acid and leucine and lower levels of a lysophosphatidylcholine were associated with hypertension. Higher levels of indole-3-lactic acid, 7 phosphatidylethanolamines, and uric acid, and lower levels of betaine and bilirubin were associated with chronic kidney disease. These findings suggest that the sexual dimorphism of the metabolome may contribute to sex differences in stroke, hypertension, and chronic kidney disease.

Abstract TP294: Sex Differences in Thrombin Generation in Patients With Acute Ischemic Stroke

Background and Purpose: Sex differences in stroke exist, including variation in stroke risk and outcome. Differences in thrombin generation may contribute to this variation between females and males. To examine this, we assessed sex differences in thrombin generation between females and males with acute ischemic stroke and the relationship to blood cell gene expression. Methods: In 97 patients with acute ischemic stroke thrombin generation was measured by thrombin generation assay. Blood cell gene expression was measured by microarray. Differences in thrombin generation between sexes were identified and the relationship to blood cell gene expression examined. Genes associated with sex differences in thrombin generation were analysed by functional pathway analysis. Results: Females and males had similar overall capacity to generate thrombin. The peak thrombin generated in females was 468.8nM (SD 91.6), comparable to males 479.3 (SD 90.8; p=0.58). Lag time, time to peak thrombin, and endogenous thrombin potential were also similar between females and males. While overall thrombin generation was comparable between females and males with stroke, differences in genes that promote this thrombin generation exist. Females with high peak thrombin had an increase in genes that promote thrombosis, and platelet activation. In contrast, males with high peak thrombin had a decrease in genes involved in thrombus degradation. Conclusion: Females and males with acute ischemic stroke have similar capacity to generate thrombin. However, differences may exist in how this thrombin generation is achieved, with females having increased thrombin signaling, and platelet activation, and males having decreased thrombus degradation. This suggests regulatory differences in thrombosis may exist between females and males that may contribute to sex differences in stroke.

Sex Differences in Thrombin Generation in Patients with Acute Ischemic Stroke.

Sex differences in stroke exist, including variation in stroke risk and outcome. Differences in thrombin generation may contribute to this variation between females and males. To examine this, we assessed sex differences in thrombin generation between females and males with acute ischemic stroke and the relationship to blood cell gene expression. In 97 patients with acute ischemic stroke, thrombin generation was measured by thrombin generation assay. Blood cell gene expression was measured by microarray. Differences in thrombin generation between sexes were identified and the relationship to blood cell gene expression examined. Genes associated with sex differences in thrombin generation were analyzed by functional pathway analysis. Females and males had similar overall capacity to generate thrombin. The peak thrombin generated in females was 468.8nM (SD 91.6), comparable to males (479.3nM;SD 90.8; p = 0.58). Lag time, time to peak thrombin, and endogenous thrombin potential were also similar between females and males. While overall thrombin generation was comparable between females and males with stroke, differences in genes that promote this thrombin generation exist. Females with high peak thrombin had an increase in genes that promote thrombosis, and platelet activation. In contrast, males with high peak thrombin had a decrease in genes involved in thrombus degradation. Females and males with acute ischemic stroke have similar capacity to generate thrombin, however, differences may exist in how this thrombin generation is achieved, with females having increased thrombin signaling, and platelet activation, and males having decreased thrombus degradation. This suggests regulatory differences in thrombosis may exist between females and males that may contribute to sex differences in stroke.

Do stroke services still show sex differences? A multicenter study

BackgroundThe issue of sex differences in stroke has gained concern in the past few years. However, multicenter studies are still required in this field. This study explores sex variation in a large number of patients and compares stroke characteristics among women in different age groups and across different countries.MethodsThis multicenter retrospective cross-sectional study aimed to compare sexes regarding risk factors, stroke severity, quality of services, and stroke outcome. Moreover, conventional risk factors in women according to age groups and among different countries were studied.ResultsEighteen thousand six hundred fifty-nine patients from 9 countries spanning 4 continents were studied. The number of women was significantly lower than men, with older age, more prevalence of AF, hypertension, and dyslipidemia. Ischemic stroke was more severe in women, with worse outcomes among women (p: < 0.0001), although the time to treatment was shorter. Bridging that was more frequent in women (p:0.002). Analyzing only women: ischemic stroke was more frequent among the older, while hemorrhage and TIA prevailed in the younger and stroke of undetermined etiology. Comparison between countries showed differences in age, risk factors, type of stroke, and management.ConclusionWe observed sex differences in risk factors, stroke severity, and outcome in our population. However, access to revascularization was in favor of women.

Sex Difference in the Impact of Dual Antiplatelet Therapy using Cilostazol for Secondary Stroke Prevention: A Sub-Analysis of CSPS.com.

Although some sex differences in stroke have been reported, differences in the effects of antiplatelet therapy for secondary stroke prevention have not been clarified. In the Cilostazol Stroke Prevention Study combination trial, patients with high-risk, non-cardioembolic ischemic stroke between 8 and 180 days after onset treated with aspirin or clopidogrel alone were recruited and randomly assigned to receive either monotherapy or dual antiplatelet therapy (DAPT) using cilostazol and followed up for 0.5-3.5 years. The primary efficacy outcome was recurrence of ischemic stroke. The safety outcome was severe or life-threatening hemorrhage. Outcomes were analyzed by sex. A total of 1,320 male patients and 558 female patients were included. The male patients had more risk factors than the female patients. In male patients, the primary endpoint occurred at a rate of 2.0 per 100-patient years in the DAPT group and 5.1 per 100 patient-years in the monotherapy group (hazard ratio (HR), 0.40; 95% confidence interval (CI), 0.23-0.68). In male patients, DAPT prolonged the time to recurrent stroke by 4.02-fold (95% CI, 1.63-9.96) compared with monotherapy. In female patients, the average annual event rates were 2.7 per 100 patient-years in the DAPT group and 3.3 per 100 patient-years in the monotherapy group (HR, 0.82; 95% CI, 0.37-1.84). Safety outcomes did not differ significantly in both male and female patients. Long-term DAPT using cilostazol reduced the recurrence of ischemic stroke and prolonged the recurrence-free time in male patients, but not in female patients.

Stroke in Women and Unique Risk Factors.

There has been a plethora of studies focused on female-specific risk factors and sex differences in stroke published in the past year. This article summarizes several of those novel studies which provide new knowledge about the field of stroke in women. The Nurses' Health Study II provides new data on the association between laparoscopically proven endometriosis and future stroke, accounting for the mediation effects of hysterectomy and oophorectomy. In a cohort of women from China, the relationship between hysterectomy, oophorectomy, and stroke is further clarified, accounting for the age at which the procedure is performed. The UK Biobank study provides new information on the relationship between oral contraceptive and hormone replacement therapy and stroke, with analytical techniques that focus on the timing of events related to duration of exposure. Finally, 2 new meta-analyses address the question of whether sex differences exist in the presentation of stroke symptoms.

Incidence, subtypes, sex differences and trends of stroke in Taiwan.

Chinese populations have been reported higher incidence of all strokes and intracerebral hemorrhage. However, few large-scale studies have evaluated changes of stroke epidemiology in the 21st century. We explored the rates of incidence of all first-ever strokes, subtypes, and 1-month case fatality by using data from the Taiwan National Health Insurance Research Database since 2004. Also, we investigated sex differences in stroke. Time-trend analysis was performed for incidence and case fatality rates of all strokes and subtypes in both sexes. The age-adjusted incidence of all strokes per 100,000 person-years decreased by 16%, from 251 (95% confidence interval [CI] 249-253) in 2004 to 210 (95% CI 209-212) in 2011 (p<0.001); it was always higher in Chinese men than in women. Among pathological subtypes, the incidence of intracerebral hemorrhage markedly decreased by 26% over the years (p<0.001), while that of ischemic stroke slightly decreased by 8%. However, when stratified by sex, the incidence of ischemic stroke decreased significantly in only women, not in men (men: p = 0.399, women: p = 0.004). Regarding the incidence of subarachnoid hemorrhage, it remained unchanged. Furthermore, the rate of 1-month case fatality decreased significantly for all strokes in both sexes (p<0.001). In Taiwan, the incidence rate of first-ever stroke decreased in both Chinese men and women in the early 21st century. Men had a higher incidence rate than women. Furthermore, a marked decrease was noted in the incidence of intracerebral hemorrhage, while a slight decrease was noted in that of ischemic stroke; however, the decreased incidence of ischemic stroke was significant in only women.

Sex-biased autophagy as a potential mechanism mediating sex differences in ischemic stroke outcome

Stroke is the second leading cause of death and a major cause of disability worldwide, and biological sex is an important determining factor in stroke incidence and pathology. From childhood through adulthood, men have a higher incidence of stroke compared with women. Abundant research has confirmed the beneficial effects of estrogen in experimental ischemic stroke but genetic factors such as the X-chromosome complement can also play an important role in determining sex differences in stroke. Autophagy is a self-degrading cellular process orchestrated by multiple core proteins, which leads to the engulfment of cytoplasmic material and degradation of cargo after autophagy vesicles fuse with lysosomes or endosomes. The levels and the activity of components of these signaling pathways and of autophagy-related proteins can be altered during ischemic insults. Ischemic stroke activates autophagy, however, whether inhibiting autophagy after stroke is beneficial in the brain is still under a debate. Autophagy is a potential mechanism that may contribute to differences in stroke progression between the sexes. Furthermore, the effects of manipulating autophagy may also differ between the sexes. Mechanisms that regulate autophagy in a sex-dependent manner in ischemic stroke remain unexplored. In this review, we summarize clinical and pre-clinical evidence for sex differences in stroke. We briefly introduce the autophagy process and summarize the effects of gonadal hormones in autophagy in the brain and discuss X-linked genes that could potentially regulate brain autophagy. Finally, we review pre-clinical studies that address the mechanisms that could mediate sex differences in brain autophagy after stroke.

Sex differences in neurovascular disorders.

Neurovascular disorders is a heterogenous group of diseases, including one of the most time critical disorders in emergency medicine; stroke. Sex differences are extensively described in neurovascular disorders, ranging from differences in symptom presentation, risk factors, treatment and outcomes. For example, women with stroke, more often present with generalized weakness, reduced consciousness and headache than men. Furthermore, there are differences in risk factors, outcomes and in the effect of secondary prevention. Women have a higher risk of cerebral venous thrombosis and developing cerebral aneurysms. In general, women have been underrepresented in trials on neurovascular disorders. This chapter provides an extensive overview of sex differences in stroke in general and in the differences specially seen in ischemic stroke, intracerebral hemorrhage, subarachnoid hemorrhage and in cerebral venous thrombosis.

Sex differences in the risk of recurrent ischemic stroke after ischemic stroke and transient ischemic attack.

Sex differences in stroke outcomes have been noted, but whether this extends to stroke recurrence is unclear. We examined sex differences in recurrent stroke using data from the Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) trial. We assessed the risk of recurrent stroke in women compared to men using data from the POINT trial. Adults >18 years old were randomized within 12 hours of onset of minor ischemic stroke or transient ischemic attack (TIA), and followed for up to 90 days for ischemic stroke, our primary outcome. We used Cox proportional hazards model adjusted for demographics and stroke risk factors to evaluate the association between sex and stroke recurrence. We used interaction term testing and prespecified subgroup analyses to determine if the association between sex and recurrent stroke differed by age (<60 versus >60 years old), locale (US versus non-US), and index event type (stroke versus TIA). Last, we evaluated whether sex modified the effect of common stroke risk factors on stroke recurrence. Of 4,881 POINT trial participants with minor stroke or high-risk TIA, 2,195 (45%) were women. During the 90-day follow-up period, 267 ischemic strokes occurred; 121 were in women and 146 in men. The cumulative risk of recurrent ischemic stroke was not significantly different among women (5.76%; 95% CI, 4.84%-6.85%) compared to men (5.67%; 95% CI, 4.83%-6.63%). Women were not at a different risk of recurrent ischemic stroke compared to men (hazard ratio [HR], 1.02; 95% CI, 0.80-1.30) in unadjusted models or after adjusting for covariates. However, there was a significant interaction of age with sex (P=0.04). Among patients <60 years old, there was a non-significantly lower risk of recurrent stroke in women compared to men (HR 0.66; 95% CI 0.42-1.05). Last, sex did not modify the association between common stroke risk factors and recurrent stroke risk. Among patients with minor stroke or TIA, the risk of recurrent ischemic stroke and the impact of common stroke risk factors did not differ between men and women.

Abstract MP57: Sex Differences in Stroke Outcome Are Associated With Constitutive Gut Dysbiosis and Stroke-Induced Gut Permeability

Sex differences in experimental stroke are well documented, such that adult males show worse outcomes compared to adult females, including greater infarct volume, increased stroke-induced mortality and more severe sensory-motor impairment. Based on recent evidence that gut dysbiosis may be an early response to stroke, the present study tested the hypothesis that in the acute phase, stroke will result in greater gut dysbiosis and greater permeability of the gut blood barrier in males as compared to females. Male and female Sprague Dawley rats (5-7 months of age) were subject to endothelin-1-induced middle cerebral artery occlusion (MCAo). Fecal samples, blood draws and sensory motor tests were collected/conducted pre and 2d after MCAo. Fecal samples were subject to 16s sequencing. Serum samples were subject to gas chromatography for short chain fatty acid (SCFA) analysis. Gut permeability was assessed by histology, biochemical markers in serum and functional assays using oral dextran gavage. We confirmed stroke-induced sex differences, including increased mortality and more severe sensory motor deficit in males as compared to age-matched female rats. Fecal 16s sequencing showed greater bacterial diversity in females at baseline (pre stroke) while 2 days after stroke, these measures were similar between the sexes. Fecal levels of SCFAs, which are usually beneficial, were higher in males. In contrast, MCAo-induced gut permeability was much worse in males as compared to females. Male rats had a decreased villus length to crypt length ratio, higher levels of biochemical gut permeability markers in serum and higher levels of fluorescent-labeled dextrans following oral gavage in serum. Additionally, males had higher serum levels of proinflammatory cytokines IL-17A, MCP-1, IL-5 and EGF compared to females after stroke. Collectively, these results indicate that the worse stroke outcomes seen in males is associated with increased gut permeability in this group. These data suggest that therapeutics that target the gut epithelium in order to reinforce the gut-blood barrier post stroke may be an effective intervention especially in populations such as the elderly or those with co-morbid conditions who have already been shown to have more permeable barriers.

Abstract P797: Sex Specific Plasma Protein Changes During Thrombectomy

Introduction: Sex differences in stroke have been apparent with premenopausal females having a lower incidence of stroke with better outcomes than postmenopausal females and males. We examined sex-specific outcomes and changes in plasma proteins following emergent large vessel occlusions. The previously published Blood and Clot Thrombectomy Registry and Collaboration (BACTRAC), clinicaltrials.gov NCT03153683, allows for analysis of plasma proteins both systemically and distal to the thrombus. Methods: Plasma samples, processed in accordance with the BACTRAC protocol, were sent to Olink to run cardiometabolic and inflammatory panels. Demographics are reported as mean±SEM. Significance determined in Prism with Mann-Whitney, t-test, or pair mixed-effect analysis. Results: We evaluated 34 subjects, &gt;18 yrs old (20 females, 14 males) enrolled in BACTRAC. There was no significant difference in age (68.9±2.7, 65.4±4.5 yrs, respectively) or comorbidities (hypertension, diabetes, cholesterolemia). Interestingly, males had a larger (p&lt;0.1) change in Modified Rankin Scale (mRS, premorbid-discharge, 3.4±1.8, 2.2±1.6, respectively) with larger infarcts (86,666±30,889 mm 3 , 36,228±10,943 mm 3 , respectively). This coincided with a lower (p&lt;0.05) CTA collateral scores for males compared to females (0.64±0.67, 1.1±0.13, respectively). 12 proteins were significantly (p&lt;0.1) higher in females, compared to males (5 proteins upregulated in both the systemic and intracranial, 3 systemic specific, and 4 intracranial specific). Males had 15 proteins significantly higher than females (3 proteins upregulated in both the systemic and intracranial, 12 systemic specific, and 0 intracranial specific). The most significant intracranial protein for females is coagulation factor XI (F11) and males is transforming growth factor beta-1 (TGFB1). Analysis of an additional 16 subjects has begun to validate the sex specific proteins. Conclusions: Unexpectedly, males have larger infarcts and less independence following large vessel occlusions in BACTRAC. We hypothesize this is due to fewer collaterals which leads to sex specific signaling patterns. Additional analysis of the plasma and subjects in BACTRAC are needed to target sex specific therapeutic.

Abstract TMP52: The Hidden Burden of Ischemic Stroke, Transient Ischemic Attack, and Atrial Fibrillation Hospitalizations Among Elderly Women

Background: US women have a greater lifetime risk of stroke than men. Risk factors such as pregnancy and hormones influence sex differences in stroke at younger ages, but less is known about hospitalization rates and the proportion of hospitalizations for ischemic stroke (IS), transient ischemic attack (TIA), and atrial fibrillation (AF) by sex in different age groups. We assessed IS, TIA, and AF hospitalizations by sex and age. Methods: IS (ICD-9 433, 434, 436), TIA (435), and AF (427.31) hospitalizations were identified in the 2014 National Inpatient Sample (NIS). Hospitalization rates per 100,000 population aged ≥18y were calculated using age- and sex-specific Census population denominators and NIS sampling weights to obtain national estimates. We also determined the proportions of condition-specific hospitalizations by sex. Results: There were 338,654 (49.8% women) patients hospitalized for IS, 90,812 (58.0% women) for TIA, and 284,770 (49.9% women) for AF. For IS, TIA, and AF, respectively, the mean ages for women were 72.7y, 71.4y, and 74.0y vs 68.8y, 69.1y, and 66.2y for men. Hospitalization rates were higher for men than women at most ages for IS and AF; however, AF rates were higher in women beginning with age 80-84y (figure). Women represented a greater proportion of hospitalizations among those aged ≥75y for all 3 conditions (58% of IS, 62.5% of TIA, and 64.7% of AF events). The proportion of women hospitalized for TIA was higher in most age groups, but for IS and AF, the proportions of women exceeded those of men beginning at ages 75-80y and 70-75y, respectively. Conclusion: Women were older when hospitalized for IS, TIA, and AF, and women aged ≥75y comprised the majority of these hospitalizations. This highlights the need for early detection of AF and IS risk in elderly women and underscores the importance of treating modifiable conditions to decrease the burden of vascular illness in women. This is critical given the overrepresentation of women among the very elderly.

Chapter 19 - Sex differences in stroke

Sex disparities within the field of stroke, including subarachnoid hemorrhages (SAHs), have been in focus during the last 2 decades. It is clear that stroke incidence is higher in men, and also that men have their first stroke earlier than women. On the other hand, women have more severe strokes, mainly because cardioembolic strokes are more common in women. This leads to higher case fatality and worse functional outcome in women. It has often been pointed out that women more often have nontraditional stroke symptoms, and therefore may seek medical help later. After discharge from the hospital, female stroke survivors live alone in many cases and are dependent on external care. Therefore, these women frequently rate their quality of life (QoL) lower than men do. Female spouses more often provide help to their male stroke survivors than the reverse, and they accept a heavier burden. These caregivers are at high risk for depression, low QoL, and low psychologic wellbeing. SAH is a special form of stroke, often caused by a ruptured aneurysm. It is about 20% more common in women. The case fatality is high, but does not differ between the sexes.

The importance of sex differences in pharmacology research

This article is part of a themed section on The Importance of Sex Differences in Pharmacology Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.21/issuetoc.

Trends in recruitment of women and reporting of sex differences in large-scale published randomized controlled trials in stroke.

Understanding of sex differences, especially in terms of the influence of sex on therapeutic interventions, can lead to improved treatment and management for all. We examined temporal and regional trends in female participation and the reporting of sex differences in stroke randomized controlled trials. Randomized controlled trials from 1990 to 2018 were identified from ClinicalTrials.gov, using keywords "stroke" and "cerebrovascular accidents." Studies were selected if they enrolled ≥100 participants, included both sexes and were published trials (identified using PubMed, Google Scholar, and Scopus). Of 1700 stroke randomized controlled trials identified, 277 were published and eligible for analysis. Overall, these randomized controlled trials enrolled only 40% females, and in the past 10 years, this percentage barely changed, peaking at 41% in 2008-2009 and 2012-2013. North American randomized controlled trials recruited the most women, at 43%, and Asia the lowest, at 40%. Among the 277 randomized controlled trials, 101 (36%) reported results according to sex, of which 91 (33%) were pre-specified analyses. The increasing trend in the number of studies reporting sex-differentiated results from 2008 to 2018 merely paralleled the increase in the number of papers published during the same time period. North American randomized controlled trials most often reported sex-specific results (42%), and Australia and Europe least often (31%). Little progress has been made in the inclusion of females and the reporting of sex in stroke randomized controlled trials. This highlights the need for key stakeholders, such as funders and journal editors, to provide clear guidance and effective implementation strategies to researchers in the scientific reporting of sex.

Sex differences in stroke and major adverse clinical events in patients with atrial fibrillation: A systematic review and meta-analysis of 993,600 patients

BackgroundAtrial fibrillation (AF) is the most commonly diagnosed arrhythmia, which is associated with an increased risk of stroke. Several studies have suggested that female AF patients could have a greater risk for stroke and thromboembolic events (TE). MethodsA systematic literature review update and meta-analysis was conducted using Pubmed. The search used the terms “atrial fibrillation”, “gender”, “sex”, “female”, “women”, “stroke”, “thromboembolism”. Main aim of the study was to compare and male AF patients for occurrence of stroke and TE. Secondary outcomes were: major bleeding, cardiovascular (CV) death and all-cause death. ResultsForty-four studies were included in the analysis including 993,603 patients (48.9% women). After pooling the data, there was a higher risk of stroke for women vs. male AF patients (hazard ratio [HR]: 1.24; 95% confidence intervals [CIs]: 1.14–1.36). Overall, TE risk was not different between female and male patients, despite sensitivity analysis left some uncertainties. No sex differences were found for major bleeding, CV death and all-cause death. A significant relationship between increasing age and the difference in stroke risk between female and male AF patients was found (Delta HR: 1.01; 95% CI: 1.00–1.03 for each year of age increase). ConclusionsFemale patients with AF are at increased risk of stroke compared to men. A significant relationship between increasing age and stroke risk in women compared to men was found, most evident at age > 65 years. Female sex may act as a stroke risk modifier, particularly in elderly and very elderly AF subjects, conferring a significant increase in stroke risk.