Sex differences and hemoglobin levels in relation to stroke outcomes

Race explains substantial variance in whole blood thiamine diphosphate concentrations

Deficiency for thiamine (vitamin B1), traditionally assessed via the activity of the thiamine-dependent enzyme erythrocyte transketolase, has been reported in individuals with alcohol use disorder (AUD) and in people with HIV; concentrations of the metabolically active diphosphate form, however, have yet to be reported in HIV cohorts and results in AUD are equivocal. In this cross-sectional study, samples from 170 AUD, 130 HIV, and 100 healthy control individuals were analyzed to test the hypothesis that AUD and HIV groups relative to healthy controls would show low whole blood thiamine diphosphate (TDP) concentrations related to peripheral neuropathy. TDP concentrations were not different in the 3 study groups (P = .6141) but were lower in Black (n = 172) relative to White (n = 155) individuals (P < .0001) regardless of group. In a multiple regression, race relative to diagnoses explained more than 10 times the variance in whole blood TDP concentrations (F4,395 = 3.5, P = .0086; r2 = 15.1]. Performance on a measure of peripheral neuropathy (2-point discrimination) was worse in the HIV and AUD cohorts relative to the healthy control group (P < .0001) but was not associated with TDP concentrations. These findings suggest that Black individuals carry a heightened vulnerability for low whole blood TDP concentrations, but the clinical significance and mechanisms underlying these results remain to be determined.

Anemia and Optimal Transfusion Thresholds in Brain-Injured Patients: A Narrative Review of the Literature

Anemia is a highly prevalent condition that may compromise oxygen delivery to vital organs, especially among the critically ill. Although current evidence supports the adoption of a restrictive transfusion strategy and threshold among the nonbleeding critically ill patient, it remains unclear whether this practice should apply to the brain-injured patient, given the predisposition to cerebral ischemia in this patient population, in which even nonprofound anemia may exert a detrimental effect on clinical outcomes. The purpose of this review is to provide an overview of the pathophysiological changes related to impaired cerebral oxygenation in the brain-injured patient and to present the available evidence on the effect of anemia and varying transfusion thresholds on the clinical outcomes of patients with acute brain injury.

Hematocrit Predicts Poor Prognosis in Patients with Acute Ischemic Stroke or Transient Ischemic Attack

This study aims to investigate the association between HCT (Hematocrit) levels and adverse outcomes in patients with acute ischemic stroke (AIS) or transient ischemic attack (TIA); 14,832 participants from the China National Stroke Registry-III with AIS or TIA were analyzed. Participants were categorized into quartiles based on baseline HCT levels. The primary outcome was poor functional outcomes (modified Rankin Scale ≥ 3) during three months, with secondary outcomes including all-cause death, stroke recurrence, and combined vascular events. Logistic regression or Cox regression models were used to assess the relationship between HCT and clinical outcomes. Compared to the third quartile, patients in the lowest quartile group showed increased risk of poor functional outcome (adjusted OR: 1.35, 95% CI: 1.15-1.58, p < 0.001), patients in the lowest quartile had a higher risk of all-cause death (adjusted HR: 1.68, 95% CI: 1.06-2.68, p = 0.028), as did those in the highest quartile (adjusted HR: 2.02, 95% CI: 1.26-3.25, p = 0.004). Sensitivity analysis shows that the association of HCT with all-cause death weakened, while the association with poor functional outcome was strengthened after excluding patients with recurrent stroke. Our results indicated that HCT level could be used as a short-term predictor for poor functional outcomes and all-cause death in patients with AIS or TIA.

Association between baseline hemoglobin level and early neurological deterioration after intravenous thrombolysis in patients with acute ischemic stroke

OBJECTIVES

To investigate the association between baseline hemoglobin level and early neurologic deterioration (END) after intravenous thrombolysis in patients with acute ischemic stroke (AIS).

METHODS

Data of AIS patients who received intravenous thrombolytic therapy at multiple hospitals across the country between January 2017 and July 2020 were collected from the online database Acute Stroke Patients for Stroke Management Quality Evaluation (CASE-Ⅱ, NCT04487340). Binary logistic regression analysis was used to study the factors affecting the occurrence of END after intravenous thrombolytic therapy, and the correlation between baseline hemoglobin level and END was investigated by limiting cubic spline curve analysis.

RESULTS

A total of 8162 patients were included. Patients with END had lower baseline hemoglobin levels (136 and 140 g/L, P<0.01) and higher rates of anemia (24.2% and 16.9%, P<0.01) compared with non-END patients. Binary logistic regression analysis showed that baseline hemoglobin level (OR=0.995, 95%CI: 0.991-0.999, P<0.05) and anemia (OR=1.238, 95%CI: 1.055-1.454, P<0.01) were independently correlated with the occurrence of END after intravenous thrombolysis in AIS patients. Restricted cubic spline regression showed that there was a U-shaped relationship between hemoglobin level and the risk of END after intravenous thrombolysis in AIS patients (P<0.01), although this relationship was only significant in male patients (P<0.05) and not in female patients (P>0.05).

CONCLUSIONS

There is a correlation between baseline hemoglobin level and the risk of END in AIS patients after intravenous thrombolysis, especially in male patients, in whom both lower and higher hemoglobin level may increase the risk of END.

Biomarkers associated with functional improvement after stroke rehabilitation: a systematic review and meta-analysis of randomized controlled trials

Objective

This study aims to identify blood and cerebrospinal fluid biomarkers that are correlated to the functional improvement of stroke patients after rehabilitation therapy, and provide ideas for the treatment and evaluation of stroke patients.

Methods

The PubMed, Web of Science, and Embase databases were searched for articles published in the English language, from inception to December 8, 2022.

Results

A total of 9,810 independent records generated 50 high-quality randomized controlled trials on 119 biomarkers. Among these records, 37 articles were included for the meta-analysis (with a total of 2,567 stroke patients), and 101 peripheral blood and cerebrospinal fluid biomarkers were included for the qualitative analysis. The quantitative analysis results revealed a moderate quality evidence that stroke rehabilitation significantly increased the level of brain-derived neurotrophic factor (BDNF) in serum. Furthermore, the low-quality evidence revealed that stroke rehabilitation significantly increased the concentration of serum noradrenaline (NE), peripheral blood superoxide dismutase (SOD), peripheral blood albumin (ALB), peripheral blood hemoglobin (HB), and peripheral blood catalase (CAT), but significantly decreased the concentration of serum endothelin (ET) and glutamate. In addition, the changes in concentration of these biomarkers were associated with significant improvements in post-stroke function. The serum BNDF suggests that this can be used as a biomarker for non-invasive brain stimulation (NIBS) therapy, and to predict the improvement of stroke patients.

Conclusion

The concentration of serum BNDF, NE, ET and glutamate, and peripheral blood SOD, ALB, HB and CAT may suggest the function improvement of stroke patients.

Association of clinical factors to functional outcomes in patients with stroke with large-vessel occlusion after endovascular thrombectomy

BACKGROUND/PURPOSE

Multiple clinical factors have been reported to be associated with functional outcomes in patients with stroke. However, little is known about prognostic predictors of functional independence in patients with stroke undergoing endovascular thrombectomy (EVT). Our study aimed to investigate the correlation between multiple prognostic variables (including EVT and rehabilitation-related parameters) and functional outcomes in patients post-EVT.

METHODS

This retrospective cohort study recruited patients hospitalized between December 2018 and March 2022. Patients with stroke with large-vessel occlusion who underwent EVT were eligible for inclusion in the study. Prognostic factors, including premorbid characteristics, laboratory data, EVT- and rehabilitation-related parameters, functional activity level, balance ability, swallowing, and sphincter function, were collected. Logistic regression and generalized linear models were used to analyze their correlations with functional outcomes.

RESULTS

A total of 148 patients were included. In the univariate logistic regression analysis, younger age, premorbid functional independence, higher hemoglobin (Hb) level, lower National Institute of Health Stroke Scale (NIHSS) score, absence of hemorrhagic transformation in 14 days, no nasogastric (NG) tube placement, earlier rehabilitation, frequent daily rehabilitation sessions, more out-of-bed rehabilitation, better ability of sitting up, better initial sitting balance, higher Barthel index (BI), absence of immobility, and neurological complications were associated with favorable outcomes at 3 months. In the stepwise regression model, the predictors of favorable function at 3 months included age, ability to sit up, and frequency of daily rehabilitation sessions; favorable outcomes at 6 months were associated with age, ability to sit up, and swallowing function.

CONCLUSION

In patients with stroke post-EVT, better functional outcomes were associated with prognostic variables, including younger age, better ability to sit up, normal swallowing function, and frequent daily rehabilitation sessions.

Liver fibrosis-4 score predicts outcome of patients with ischemic stroke undergoing intravenous thrombolysis

Some evidence suggests a possible influence of liver disease on stroke prognosis. We investigated the association between fibrosis-4 (FIB-4) score, a marker of liver disease, and the 3-month outcome in patients with ischemic stroke undergoing intravenous thrombolysis. We also evaluated the rate of symptomatic intracranial hemorrhage after thrombolysis. In this prospective cohort study, we enrolled consecutive patients with ischemic stroke treated with thrombolysis who had a 3-month follow-up. The FIB-4 score was calculated and the validated cut-off values were used to indicate high/low risk of advanced liver fibrosis. The primary outcome was 3-month poor prognosis estimated as a modified Rankin scale score ≥3. Of the 264 included patients, 131 (49.62%) had a 3-month mRS ≥3, with a significantly higher FIB-4 score, compared to those with a mRS <3 score (_adjp <0.001). When adjusted for possible confounders by multivariate logistic regression, FIB-4 score remained a significant predictor of poor outcome (OR 1.894, p = 0.011), along with history of atrial fibrillation (OR 3.488, p = 0.017), admission NIHSS score (OR 1.305, p < 0.001), and low values of hemoglobin (OR 0.730, p < 0.001). Mechanical thrombectomy had a favorable effect on patients' outcome (OR 0.201, p = 0.005). The risk of poor 3-month outcome was significantly higher among the 32 patients (12.1%) with high risk of severe fibrosis (p = 0.007). FIB-4 score values were also related to symptomatic intracranial hemorrhage (p = 0.004), specifically among patients with high probability of advanced hepatic fibrosis (p = 0.037). FIB-4 score can be considered as a promising independent predictor of poor prognosis in patients with acute ischemic stroke undergoing intravenous thrombolysis.

Relationship Between the Hemoglobin-to-Red Cell Distribution Width Ratio and All-Cause Mortality in Ischemic Stroke Patients with Atrial Fibrillation: An Analysis from the MIMIC-IV Database

AIM

To investigate the association between the hemoglobin-to-red cell distribution width (RDW) ratio (HRR) and all-cause mortality in ischemic stroke patients with atrial fibrillation (AF).

DESIGN

This study was a retrospective cohort analysis. In total, 1018 ischemic stroke patients with AF were enrolled using the Medical Information Mart for Intensive Care database, (MIMIC)-IV. The patients were divided into four groups according to the HRR values. The primary outcome was 180-day all-cause mortality.

METHODS

Multivariate Cox proportional risk regression models were used to examine the association between HRR and all-cause mortality. The non-linear relationship between HRR and all-cause mortality was confirmed using a Cox proportional risk regression model fitted by cubic spline function and smooth curve fitting.

RESULTS

A total of 246/1018 patients (24.17%) died. The serum HRR values were negatively associated with 180-day all-cause mortality (hazard ratio (HR) 0.80, 95% confidence interval (CI) 0.68-0.94). A two-piecewise regression model was used to obtain a threshold inflection point value of 9.74. The HR and the 95% CI on the left inflection point were 0.73 and 0.61-0.87 (p = 0.0005); on the right inflection point they were 1.06 and 0.82-1.38 (p = 0.6383).

CONCLUSION

The relationship between all-cause mortality and the HRR values was non-linear in ischemic stroke patients with AF. All-cause mortality and HRR values were negatively correlated when the HRR value was ≤9.74.

Both Ends of Values in the Hemoglobin Spectrum Are Associated with Adverse Stroke Outcomes

BACKGROUND AND PURPOSE

Existing studies on the association between hemoglobin values and stroke outcomes mostly focus on the lower side and mortality, often the only and primary endpoint. The current study was conducted to assess the association between hemoglobin concentration and a variety of poor stroke outcomes in patients with acute ischemic stroke.

METHODS

We studied 8,321 patients enrolled in the China National Stroke Registry (CNSR) between 2007 and 2008. Patients were divided into 7 groups, and a logistic regression model was used to evaluate the association. Endpoints of interest included 1-year all-cause mortality, stroke recurrence, combined endpoint, and stroke disability. Stroke disability was defined as a modified Rankin Scale of 2-6.

RESULTS

Patients with low and high hemoglobin values (≤11.6 g/dL and >16.1 g/dL) had higher proportion of poststroke adverse events than those in other groups. As compared with the fourth group of hemoglobin values of 13.5-14.2 g/dL, the adjusted odds ratios (ORs) with 95% confidence interval (CI) of low hemoglobin values (≤11.6 g/dL) were 2.25 (1.72-2.93) for all-cause mortality, 1.30 (1.04-1.61) for stroke recurrence, 1.63 (1.33-2.01) for combined endpoint, and 1.37 (1.12-1.67) for stroke disability, respectively. And, the ORs of high hemoglobin values (>16.1 g/dL) for adverse stroke outcomes were 1.72 (1.25-2.37), 1.43 (1.13-1.82), 1.43 (1.13-1.81), and 1.31 (1.06-1.63), respectively. Stratified analysis showed significant interactions between sex and categories of hemoglobin values for all-cause mortality (p = 0.05), stroke recurrence (p = 0.03), and combined endpoint (p = 0.01) but not for stroke disability (p = 0.24).

CONCLUSIONS

Our study found both low and high hemoglobin values were associated with adverse stroke outcomes including all-cause mortality, stroke recurrence, combined endpoint, and stroke disability, which showed a U-shaped association. And, significant interactions between sex and hemoglobin concentration on all-cause mortality and stroke recurrence were also identified.

Anemia Is a Risk Factor for the Development of Ischemic Stroke and Post-Stroke Mortality

BACKGROUND

anemia is known to be a risk factor for developing ischemic stroke in long-term follow-up studies, and it is also known to increase the risk of death in ischemic stroke patients. We aimed to determine the association of anemia with the risk of ischemic stroke and the risk of death after ischemic stroke.

METHODS

The study included patients from National Health Insurance Service cohort, from January 2005 to December 2015. Anemia patients were defined as those with confirmed diagnostic codes and related medications in the sample cohort, and patients under the age of 18 were excluded. To perform a comparative analysis with the control group, twice as many patients were extracted by propensity score matching. The effects of anemia on the development of ischemic stroke were analyzed.

RESULTS

A total of 58,699 patients were newly diagnosed with anemia during the study period. In anemia group, the rate of ischemic stroke occurring within 1 year was 0.550%, and the rate was 0.272% in the control group. The odds ratio of anemia related to ischemic stroke was 1.602 (95% confidence intervals (CI) 1.363-1.883). During the follow-up period, 175 out of 309 (56.6%) died in anemia group, and 130 out of 314 (41.4%) died in control group. The anemia group showed a higher risk of death than the control group (Hazard ratio 1.509, 95% CI 1.197-1.902).

CONCLUSION

Analysis of the nationwide health insurance data revealed that anemia is one of the risk factors for the development of ischemic stroke, and also an independent prognostic factor affecting post-stroke mortality.

The Hemoglobin, Albumin, Lymphocyte, and Platelet (HALP) Score Is Associated With Poor Outcome of Acute Ischemic Stroke

Background: The combined index of hemoglobin, albumin, lymphocyte, and platelet (HALP) is considered a novel score to reflect systemic inflammation and nutritional status. This study aimed to investigate the association between HALP score and poor outcome in patients with acute ischemic stroke (AIS). Methods: Consecutive AIS patients within 24 h after onset were prospectively enrolled. Poor outcome was a combination of a new stroke event (ischemic and hemorrhagic) and all-cause death within 90 days and 1 year. The association between HALP score and poor outcome was analyzed using Cox proportional hazards. Results: A total of 1,337 patients were included. Overall, 60 (4.5%) and 118 (8.8%) patients experienced poor outcome within 90 days and 1 year, respectively. Patients in the highest tertile of HALP score had a lower risk of poor outcome within 90 days and 1 year (hazard ratio: 0.25 and 0.42; 95% confidence intervals: 0.11-0.57 and 0.25-0.69, P for trend <0.01 for all) compared with those in the lowest tertile after adjusting relevant confounding factors. Adding HALP score to the conventional risk factors improved prediction of poor outcome in patients with AIS within 90 days and 1 year (net reclassification index, 48.38 and 28.95%; integrated discrimination improvement, 1.51 and 1.51%; P < 0.05 for all). Conclusions: Increased HALP score was associated with a decreased risk of recurrent stroke and death within 90 days and 1 year after stroke onset, suggesting that HALP score may serve as a powerful indicator for AIS.

Effect of haemoglobin levels on outcome in intravenous thrombolysis-treated stroke patients

INTRODUCTION

Alterations in haemoglobin levels are frequent in stroke patients. The prognostic meaning of anaemia and polyglobulia on outcomes in patients treated with intravenous thrombolysis is ambiguous.

PATIENTS AND METHODS

In this prospective multicentre, intravenous thrombolysis register-based study, we compared haemoglobin levels on hospital admission with three-month poor outcome (modified Rankin Scale 3-6), mortality and symptomatic intracranial haemorrhage (European Cooperative Acute Stroke Study II-criteria (ECASS-II-criteria)). Haemoglobin level was used as continuous and categorical variable distinguishing anaemia (female: <12 g/dl; male: <13 g/dl) and polyglobulia (female: >15.5 g/dl; male: >17 g/dl). Anaemia was subdivided into mild and moderate/severe (female/male: <11 g/dl). Normal haemoglobin level (female: 12.0-15.5 g/dl, male: 13.0-17.0 g/dl) served as reference group. Unadjusted and adjusted odds ratios with 95% confidence intervals were calculated with logistic regression models.

RESULTS

Among 6866 intravenous thrombolysis-treated stroke patients, 5448 (79.3%) had normal haemoglobin level, 1232 (17.9%) anaemia - of those 903 (13.2%) had mild and 329 (4.8%) moderate/severe anaemia - and 186 (2.7%) polyglobulia. Anaemia was associated with poor outcome (ORadjusted 1.25 (1.05-1.48)) and mortality (ORadjusted 1.58 (1.27-1.95)). In anaemia subgroups, both mild and moderate/severe anaemia independently predicted poor outcome (ORadjusted 1.29 (1.07-1.55) and 1.48 (1.09-2.02)) and mortality (ORadjusted 1.45 (1.15-1.84) and ORadjusted 2.00 (1.46-2.75)). Each haemoglobin level decrease by 1 g/dl independently increased the risk of poor outcome (ORadjusted 1.07 (1.02-1.11)) and mortality (ORadjusted 1.08 (1.02-1.15)). Anaemia was not associated with occurrence of symptomatic intracranial haemorrhage. Polyglobulia did not change any outcome.

DISCUSSION

The more severe the anaemia, the higher the probability of poor outcome and death. Severe anaemia might be a target for interventions in hyperacute stroke.

CONCLUSION

Anaemia on admission, but not polyglobulia, is a strong and independent predictor of poor outcome and mortality in intravenous thrombolysis-treated stroke patients.

Commonalities and differences in abnormal peripheral metabolites between patients with fibromyalgia and complex regional pain syndrome

Background: Fibromyalgia (FM) and complex regional pain syndrome (CRPS) share many pathological mechanisms related to chronic pain that could contribute to multifactorial pathological mechanisms.Methods: We investigated peripheral metabolites in FM and CRPS patients compared to healthy controls based on cross-sectional study.Results: Mean corpuscular hemoglobin (p < 0.001), mean corpuscular volume (p = 0.014), and total bilirubin levels (p = 0.017) were lower in FM patients than in healthy controls. On the other hand, CRPS patients showed lower levels of total bilirubin than healthy controls (p = 0.037). Creatinine level was lower in FM patients (p = 0.057) compared to healthy controls, particularly when comparing the low-hemoglobin subgroup among FM patients (p = 0.035) with the low-hemoglobin subgroup among healthy controls. Red blood cell count (r = -0.620, p = 0.031), hematocrit (r = -0.593, p = 0.042), and creatinine level (r = -0.598, p = 0.040) showed negative correlations with McGill Pain Questionnaire-Affective (MPQ-A) scores in FM patients. A negative correlation was observed between MCV and McGill Pain Questionnaire-Sensory scores (r = -0.680, p = 0.015) in CRPS patients.Conclusion: We found specific peripheral metabolites that may exhibit different tendency between FM and CRPS patients as well as some common metabolites, which may be associated with peripheral pathology in the patients. Considering this study had a few limitations such as a small sample sizes and using a liberal threshold of significance in the correlation analysis, future studies with larger sample sizes may be needed to generalize these findings.

Sex-specific Associations Between Serum Hemoglobin Levels and the Risk of Cause-specific Death in Korea Using the National Health Insurance Service-National Health Screening Cohort (NHIS HEALS)

Objectives

The purpose of this study was to determine the associations between blood hemoglobin (Hgb) levels and the risk of death by specific causes.

Methods

Using the National Health Insurance Services-National Health Screening Cohort (n=487 643), we classified serum Hgb levels into 6 sex-specific groups. Cox regression analysis was used to analyze the associations between Hgb levels and the risk of cause-specific death.

Results

Hgb levels in male population showed a U-shaped, J-shaped, or inverse J-shaped association with the risk of death from ischemic heart disease, acute myocardial infarction, liver cancer, cirrhosis and chronic obstructive pulmonary disease (COPD) (all non-linear p<0.05; hazard ratio [HR]; 95% confidence interval [CI]) for the lowest and the highest Hgb levels for the risk of each cause of death in male population: HR, 1.14; 95% CI, 0.98 to 1.34; HR, 2.87; 95% CI, 1.48 to 5.57; HR, 1.16; 95% CI, 0.96 to 1.40; HR, 3.05; 95% CI, 1.44 to 6.48; HR, 1.36; 95% CI, 1.18 to 1.56; HR, 2.11; 95% CI, 1.05 to 4.26; HR, 3.64; 95% CI, 2.49 to 5.33; HR, 5.97; 95% CI, 1.44 to 24.82; HR, 1.62; 95% CI, 1.14 to 2.30; HR, 3.84; 95% CI, 1.22 to 12.13, respectively), while in female population, high Hgb levels were associated with a lower risk of death from hypertension and a higher risk of death from COPD (overall p<0.05; HR, 1.86; 95% CI, 1.29 to 2.67 for the lowest Hgb levels for hypertension; overall p<0.01, HR, 6.60; 95% CI, 2.37 to 18.14 for the highest Hgb levels for COPD). For the risk of lung cancer death by Hgb levels, a linear negative association was found in male population (overall p<0.01; the lowest Hgb levels, HR, 1.17; 95% CI, 1.05 to 1.33) but an inverse J-shaped association was found in female population (non-linear p=0.01; HR, 1.25; 95% CI, 0.96 to 1.63; HR, 2.58; 95% CI, 1.21 to 5.50).

Conclusions

Both low and high Hgb levels were associated with an increased risk of death from various causes, and some diseases showed different patterns according to sex.

A Systems Analysis of the Relationships Between Anemia and Ischemic Stroke Rehabilitation Based on RNA-Seq Data

Ischemic stroke (IS) is one of the main causes of morbidity and disability worldwide due to its complex mechanism. Anemia was characterized as a risk factor of IS because the direct connection between central nervous system, blood supply, and tissue oxygen delivery. As the key oxygen-carrying molecule in the blood, hemoglobin (Hb) may be decisive in the destiny of penumbral area or influence the brain recovery and neurologic function, which could finally affect the outcome of IS. However, more detailed information on the expression levels of Hb related genes were still lacking possibly because the concentration of Hb was determined by the genes’ expression several hours ago, which may make the research more difficult to perform. This time gap between gene expressions and protein concentration could make these genes predictive bio-markers for IS outcome. In this study, we choose 28 IS patients, of which 12 were suffering from anemia. Statistical analysis results showed that the outcomes of the patients were different when dividing them into two groups characterized by Hb concentration. 2 sex and age matched patients were first chosen to perform RNA-seq analysis on, on two occasions at two different time points, after which the Hb counts were tested at least 24 h after sequencing. Results showed that the outcome of anemia patients was poor compared with non-anemia patients. Two other patients were then chosen for analysis which excluded the coincidence of other factors. The results showed that the low value of Hb under 13 g/dL in men were closely related to the poor outcome of IS patients. Differently expressed Hb related genes were tested and six genes were shown to be positively correlated with the recovery degree of IS patients: ELANE, FGF23, HBB, PIEZO1, RASA4, and PRTN3. Gene CPM was shown to be negatively correlated with clinical outcomes. All of the seven genes were validated to be related to strokes using real-time PCR or literature searches. Taken together, these genes could be considered as new predictors for the recovery of IS patients.

Sex differences in stress and immune responses during confinement in Antarctica

Background

Antarctica challenges human explorers by its extreme environment. The effects of these unique conditions on the human physiology need to be understood to best mitigate health problems in Antarctic expedition crews. Moreover, Antarctica is an adequate Earth-bound analogue for long-term space missions. To date, its effects on human physiology have been studied mainly in male cohorts though more female expeditioners and applicants in astronaut training programs are selected. Therefore, the identification of sex differences in stress and immune reactions are becoming an even more essential aim to provide a more individualized risk management.

Methods

Ten female and 16 male subjects participated in three 1-year expeditions to the German Antarctic Research Station Neumayer III. Blood, saliva, and urine samples were taken 1–2 months prior to departure, subsequently every month during their expedition, and 3–4 months after return from Antarctica. Analyses included cortisol, catecholamine and endocannabinoid measurements; psychological evaluation; differential blood count; and recall antigen- and mitogen-stimulated cytokine profiles.

Results

Cortisol showed significantly higher concentrations in females than males during winter whereas no enhanced psychological stress was detected in both sexes. Catecholamine excretion was higher in males than females but never showed significant increases compared to baseline. Endocannabinoids and N-acylethanolamides increased significantly in both sexes and stayed consistently elevated during the confinement. Cytokine profiles after in vitro stimulation revealed no sex differences but resulted in significant time-dependent changes. Hemoglobin and hematocrit were significantly higher in males than females, and hemoglobin increased significantly in both sexes compared to baseline. Platelet counts were significantly higher in females than males. Leukocytes and granulocyte concentrations increased during confinement with a dip for both sexes in winter whereas lymphocytes were significantly elevated in both sexes during the confinement.

Conclusions

The extreme environment of Antarctica seems to trigger some distinct stress and immune responses but—with the exception of cortisol and blood cell counts—without any major relevant sex-specific differences. Stated sex differences were shown to be independent of enhanced psychological stress and seem to be related to the environmental conditions. However, sources and consequences of these sex differences have to be further elucidated.

Association of anemia and hemoglobin decrease during acute stroke treatment with infarct growth and clinical outcome

Background and purpose

Anemia is associated with worse outcome in stroke, but the impact of anemia with intravenous thrombolysis or endovascular therapy has hardly been delineated. The aim of this study was to analyze the role of anemia on infarct evolution and outcome after acute stroke treatment.

Methods

1158 patients from Bern and 321 from Los Angeles were included. Baseline data and 3 months outcome assessed with the modified Rankin Scale were recorded prospectively. Baseline DWI lesion volumes were measured in 345 patients and both baseline and final infarct volumes in 180 patients using CT or MRI. Multivariable and linear regression analysis were used to determine predictors of outcome and infarct growth.

Results

712 patients underwent endovascular treatment and 446 intravenous thrombolysis. Lower hemoglobin at baseline, at 24h, and nadir until day 5 predicted poor outcome (OR 1.150–1.279) and higher mortality (OR 1.131–1.237) independently of treatment. Decrease of hemoglobin after hospital arrival, mainly induced by hemodilution, predicted poor outcome and had a linear association with final infarct volumes and the amount and velocity of infarct growth. Infarcts of patients with newly observed anemia were twice as large as infarcts with normal hemoglobin levels.

Conclusion

Anemia at hospital admission and any hemoglobin decrease during acute stroke treatment affect outcome negatively, probably by enlarging and accelerating infarct growth. Our results indicate that hemodilution has an adverse effect on penumbral evolution. Whether hemoglobin decrease in acute stroke could be avoided and whether this would improve outcome would need to be studied prospectively.

Sex and Stroke in Thrombolyzed Patients and Controls

Background and Purpose—

We hypothesized that any sex-related difference in outcome poststroke is explained by other prognostic factors and that the response to intravenous recombinant tissue-type plasminogen activator (r-tPA) is equal in males and females after adjustment for such factors.

Methods—

We accessed an independent collection of randomized clinical trials—the VISTA (Virtual International Stroke Trials Archive). Data were preprocessed by selecting complete cases (n=8028) and matching females to males (coarsened exact matching, n=4575, 24.3% r-tPA). Outcome was assessed by the 7-point modified Rankin Scale (mRS) measured at 90 days after ischemic stroke. Relationship among variables was estimated by adjusted regression analysis.

Results—

In nonthrombolyzed patients, ordinal analysis of mRS adjusting for stroke- and sex-related prognostic factors suggested comparable outcomes for females and males (odds ratio, 0.96; 95% confidence interval, 0.85–1.06). Females responded comparably to r-tPA as did males, irrespective of the outcome definition of mRS (ordinal: P Interaction =0.46, relative excess risk because of interaction=0). The number needed to treat was 6.8 and 11.2 for 1 female to achieve mRS score of 0 to 2 and 0 to 1, which was highly congruent with males. Analysis for a nonlinear variation of age-by-sex revealed a good outcome for females <45 years with significant disadvantage thereafter (mRS score of 0–2: P Interaction =0.004). No relationship between sex, r-tPA, and bleeding complications was evident.

Conclusions—

Functional outcome (mRS) without r-tPA was overall similar between the sexes, as was the response to r-tPA. Nonlinear sex-by-age interaction improved estimates of functional independence; this should be considered in sex-related studies in stroke.

Sex differences in stroke: a socioeconomic perspective

BACKGROUND

A number of studies have explored the issue of sex differences in stroke from biomedical perspective; however, there are still large gaps in the existing knowledge. The purpose of this study was to assess whether the differences in socioeconomic status and living conditions between men and women may explain the part of the sex differences in incidence and outcomes of stroke.

METHODS

All stroke participants aged ≥60 years admitted in Vaseie Hospital in Sabzevar, Iran, from March 21, 2013, until March 20, 2014, were included in this study. Computerized tomography and magnetic resonance imaging were used to confirm stroke. A series of χ2 tests were performed and Statistical Program for Social Sciences, Version 21.0, was used to investigate the potential differences between older men and women in stroke incidence and outcomes.

RESULTS

A total of 159 incident stroke cases were documented during 1 year. The annual rate of stroke was statistically significantly higher in elderly women than in elderly men (401 vs 357 per 100,000; P<0.001). Female elderly participants had significantly lower socioeconomic status, poorer living conditions, and higher lifetime history of depression, hypertension, and diabetes mellitus than their male counterparts.

CONCLUSION

The findings from this study showed that elderly women are more adversely affected by stroke in terms of incidence and outcomes of stroke than elderly men. The most noticeable result is that sex differences in socioeconomic status and living conditions may result in increased incidence of stroke and poorer outcomes in elderly women. Therefore, it is imperative to identify vulnerable elderly women and provide them appropriate treatment and services.

Hemoglobin Concentration and Risk of Incident Stroke in Community-Living Adults

BACKGROUND AND PURPOSE

In previous observational studies, hemoglobin concentrations have been associated with an increased risk of stroke. However, these studies were limited by a relatively low number of stroke events, making it difficult to determine whether the association of hemoglobin and stroke differed by demographic or clinical factors.

METHODS

Using Cox proportional hazards analysis and Kaplan-Meier plots, we examined the association of baseline hemoglobin concentrations with incident stroke in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a cohort of black and white adults aged ≥45 years.

RESULTS

A total of 518 participants developed stroke over a mean 7±2 years of follow-up. There was a statistically significant interaction between hemoglobin and sex (P=0.05) on the risk of incident stroke. In Cox regression models adjusted for demographic and clinical variables, there was no association of baseline hemoglobin concentration with incident stroke in men, whereas in women, the lowest (<12.4 g/dL) and highest (>14.0 g/dL) quartiles of hemoglobin were associated with higher risk of stroke when compared with the second quartile (12.4-13.2 g/dL; quartile 1: hazard ratio, 1.59; 95% confidence interval, 1.09-2.31; quartile 2: referent; quartile 3: hazard ratio, 0.91; 95% confidence interval, 0.59-1.38; quartile 4: hazard ratio, 1.59; 95% confidence interval, 1.08-2.35). Similar results were observed in models stratified by hemoglobin and sex and when hemoglobin was modeled as a continuous variable using restricted quadratic spline regression.

CONCLUSIONS

Lower and higher hemoglobin concentrations were associated with a higher risk of incident stroke in women. No such associations were found in men.

Outcomes after Stroke in Patients with Previous Pressure Ulcer: A Nationwide Matched Retrospective Cohort Study

BACKGROUND

Factors associated with poststroke adverse events were not completely understood. The purpose of this study was to investigate whether stroke patients with previous pressure ulcers had more adverse events after stroke.

METHODS

Using the claims data from Taiwan's National Health Insurance Research Database, we conducted a retrospective cohort study matched by propensity score. Three thousand two first-ever stroke patients with previous pressure ulcer and 3002 first-ever stroke patients without pressure ulcer were investigated between 2002 and 2009. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of complications and 30-day mortality after stroke associated with previous pressure ulcer were calculated in the multivariate logistic regressions.

RESULTS

Patients with pressure ulcer had significantly higher risk than control for poststroke urinary tract infection (OR: 1.56, 95% CI: 1.38-1.78), pneumonia (OR: 1.35, 95% CI: 1.16-1.58), gastrointestinal bleeding (OR: 1.31, 95% CI: 1.04-1.66), and epilepsy (OR: 1.84, 95% CI: 1.83-1.85). Stroke patients with pressure ulcer had increased 30-day poststroke mortality (OR: 2.01, 95% CI: 1.55-2.61), particularly in those treated with debridement (OR: 2.87, 95% CI: 1.85-4.44) or high quantity of antibiotics (OR: 4.01, 95% CI: 2.10-7.66). Pressure ulcer was associated with poststroke mortality in both genders and patients aged 60 years or older.

CONCLUSIONS

This study showed increased poststroke complications and mortality in patients with previous pressure ulcer, which suggests the urgent need for monitoring stroke patients for pressure ulcer history.

Off-hour effect on 3-month functional outcome after acute ischemic stroke: a prospective multicenter registry

Background and Purpose

The time of hospital arrival may have an effect on prognosis of various vascular diseases. We examined whether off-hour admission would affect the 3-month functional outcome in acute ischemic stroke patients admitted to tertiary hospitals.

Methods

We analyzed the ‘off-hour effect’ in consecutive patients with acute ischemic stroke using multi-center prospective stroke registry. Work-hour admission was defined as when the patient arrived at the emergency department between 8 AM and 6 PM from Monday to Friday and between 8 AM and 1 PM on Saturday. Off-hour admission was defined as the rest of the work-hours and statutory holidays. Multivariable logistic regression was used to analyze the association between off-hour admission and 3-month unfavorable functional outcome defined as modified Rankin Scale (mRS) 3–6. Multivariable model included age, sex, risk factors, prehospital delay time, intravenous thrombolysis, stroke subtypes and severity as covariates.

Results

A total of 7075 patients with acute ischemic stroke were included in this analysis: mean age, 67.5 (±13.0) years; male, 58.6%. In multivariable analysis, off-hour admission was not associated with unfavorable functional outcome (OR, 0.89; 95% CI, 0.72–1.09) and mortality (OR, 1.09; 95% CI, 0.77–1.54) at 3 months. Moreover, off-hour admission did not affect a statistically significant shift of 3-month mRS distributions (OR, 0.90; 95% CI, 0.78–1.05).

Conclusions

‘Off-hour’ admission is not associated with an unfavorable 3-month functional outcome in acute ischemic stroke patients admitted to tertiary hospitals in Korea. This finding indicates that the off-hour effects could be overcome with well-organized stroke management strategies.

Tracheostomy after severe ischemic stroke: a population-based study

BACKGROUND

Stroke can result in varying degrees of respiratory failure. Some patients require tracheostomy in order to facilitate weaning from mechanical ventilation, long-term airway protection, or a combination of the two. Little is known about the rate and predictors of this outcome in patients with severe stroke. We aim to determine the rate of tracheostomy after severe ischemic stroke.

METHODS

Using the Nationwide Inpatient Sample database from 2007 to 2009, patients hospitalized with ischemic stroke were identified based on validated International Classification of Diseases, 9th revision, Clinical Modification codes. Next, patients with stroke were stratified based on whether they were treated with or without decompressive craniectomy, and the rate of tracheostomy for each group was determined. A logistic regression analysis was used to identify predictors of tracheostomy after decompressive craniectomy. Survey weights were used to obtain nationally representative estimates.

RESULTS

In 1,550,000 patients discharged with ischemic stroke nationwide, the rate of tracheostomy was 1.3% (95% confidence interval [CI], 1.2-1.4%), with a 1.3% (95% CI, 1.1-1.4%) rate in patients without decompressive craniectomy and a 33% (95% CI, 26-39%) rate in the surgical treatment group. Logistic regression analysis identified pneumonia as being significantly associated with tracheostomy after decompressive craniectomy (odds ratio, 3.95; 95% CI, 1.95-6.91).

CONCLUSIONS

Tracheostomy is common after decompressive craniectomy and is strongly associated with the development of pneumonia. Given its impact on patient function and potentially modifiable associated factors, tracheostomy may warrant further study as an important patient-centered outcome among patients with stroke.