Hypercortisolemia in acute stroke is related to the inflammatory response

Mechanistic insights on impact of Adenosine monophosphate-activated protein kinase (AMPK) mediated signalling pathways on cerebral ischemic injury

Cerebral ischemia is the primary cause of morbidity and mortality worldwide due to the perturbations in the blood supply to the brain. The brain triggers a cascade of complex metabolic and cellular defects in response to ischemic stress. However, due to the disease heterogeneity and complexity, ischemic injury's metabolic and cellular pathologies remain elusive, and the link between various pathological mechanisms is difficult to determine. Efforts to develop effective treatments for these disorders have yielded limited efficacy, with no proper cure available to date. Recent clinical and experimental research indicates that several neuronal diseases commonly coexist with metabolic dysfunction, which may aggravate neurological symptoms. As a result, it stands to a reason that metabolic hormones could be a potential therapeutic target for major NDDs. Moreover, fasting signals also influence the circadian clock, as AMPK phosphorylates and promotes the degradation of the photo-sensing receptor (cryptochrome). Here, the interplay of AMPK signaling between metabolic regulation and neuronal death and its role for pathogenesis and therapeutics has been studied. We have also highlighted a significant signaling pathway, i.e., the adenosine monophosphate-activated protein kinase (AMPK) involved in the relationship between the metabolism and ischemia, which could be used as a target for future studies therapeutics, and review some of the clinical progress in this area.

A Comparative Study of Two Models of Intraluminal Filament Middle Cerebral Artery Occlusion in Rats: Long-Lasting Accumulation of Corticosterone and Interleukins in the Hippocampus and Frontal Cortex in Koizumi Model

Recently, we have shown the differences in the early response of corticosterone and inflammatory cytokines in the hippocampus and frontal cortex (FC) of rats with middle cerebral artery occlusion (MCAO), according to the methods of Longa et al. (LM) and Koizumi et al. (KM) which were used as alternatives in preclinical studies to induce stroke in rodents. In the present study, corticosterone and proinflammatory cytokines were assessed 3 months after MCAO. The most relevant changes detected during the first days after MCAO became even more obvious after 3 months. In particular, the MCAO-KM (but not the MCAO-LM) group showed significant accumulation of corticosterone and IL1β in both the ipsilateral and contralateral hippocampus and FC. An accumulation of TNFα was detected in the ipsilateral hippocampus and FC in the MCAO-KM group. Thus, unlike the MCAO-LM, the MCAO-KM may predispose the hippocampus and FC of rats to long-lasting bilateral corticosterone-dependent distant neuroinflammatory damage. Unexpectedly, only the MCAO-LM rats demonstrated some memory deficit in a one-trial step-through passive avoidance test. The differences between the two MCAO models, particularly associated with the long-lasting increase in glucocorticoid and proinflammatory cytokine accumulation in the limbic structures in the MCAO-KM, should be considered in the planning of preclinical experiments, and the interpretation and translation of received results.

The etiology of poststroke-depression: a hypothesis involving HPA axis

Approximately, one in three ischemic stroke survivors suffered from depression, namely, post-stroke depression (PSD). PSD affects functional rehabilitation and may lead to poor quality of life of patients. There are numerous explanations about the etiologies of PSD. Here, we speculated that PSD are likely to be the result of specific changes in brain pathology. We hypothesized that the stroke-induced hyperactivity of hypothalamic-pituitary-adrenal (HPA) axis plays an important role in PSD. Stroke initiates a complex sequence of events in neuroendocrine system including HPA axis. The HPA axis is involved in the pathophysiology of depression, especially, the overactivity of the HPA axis occurs in major depressive disorder. This review summarizes the possible etiologies of PSD, focusing on the stroke-induced activation of HPA axis, mainly including the stress followed by severe brain damage and the proinflammatory cytokines release. The role of hyperactive of HPA axis in PSD was discussed in detail, which includes the role of high level corticotropin-releasing hormone in PSD, the effects of glucocorticoids on the alterations in specific brain structures, the expression of enzymes, excitotoxicity, the change in intestinal permeability, and the activation of microglia. The relationship between neuroendocrine regulation and inflammation was also described. Finally, the therapy of PSD by regulating HPA axis, neuroendocrine, and immunity was discussed briefly. Nevertheless, the change of HPA axis and the occurring of PSD maybe interact and promote on each other, and future investigations should explore this hypothesis in more depth.

Oxytocin and vasopressin in the hippocampus

Oxytocin (OXT) and vasopressin (AVP) are related neuropeptides that exert a wide range of effects on general health, homeostasis, development, reproduction, adaptability, cognition, social and nonsocial behaviors. The two peptides are mainly of hypothalamic origin and execute their peripheral and central physiological roles via OXT and AVP receptors, which are members of the G protein-coupled receptor family. These receptors, largely distributed in the body, are abundantly expressed in the hippocampus, a brain region particularly vulnerable to stress exposure and various lesions. OXT and AVP have important roles in the hippocampus, by modulating important processes like neuronal excitability, network oscillatory activity, synaptic plasticity, and social recognition memory. This chapter includes an overview regarding OXT and AVP structure, synthesis, receptor distribution, and functions, focusing on their relationship with the hippocampus and mechanisms by which they influence hippocampal activity. Brief information regarding hippocampal structure and susceptibility to lesions is also provided. The roles of OXT and AVP in neurodevelopment and adult central nervous system function and disorders are highlighted, discussing their potential use as targeted therapeutic tools in neuropsychiatric diseases.

Ischemic Stroke, Glucocorticoids, and Remote Hippocampal Damage: A Translational Outlook and Implications for Modeling

Progress in treating ischemic stroke (IS) and its delayed consequences has been frustratingly slow due to the insufficient knowledge on the mechanism. One important factor, the hypothalamic-pituitary-adrenocortical (HPA) axis is mostly neglected despite the fact that both clinical data and the results from rodent models of IS show that glucocorticoids, the hormones of this stress axis, are involved in IS-induced brain dysfunction. Though increased cortisol in IS is regarded as a biomarker of higher mortality and worse recovery prognosis, the detailed mechanisms of HPA axis dysfunction involvement in delayed post-stroke cognitive and emotional disorders remain obscure. In this review, we analyze IS-induced HPA axis alterations and supposed association of corticoid-dependent distant hippocampal damage to post-stroke brain disorders. A translationally important growing point in bridging the gap between IS pathogenesis and clinic is to investigate the involvement of the HPA axis disturbances and related hippocampal dysfunction at different stages of SI. Valid models that reproduce the state of the HPA axis in clinical cases of IS are needed, and this should be considered when planning pre-clinical research. In clinical studies of IS, it is useful to reinforce diagnostic and prognostic potential of cortisol and other HPA axis hormones. Finally, it is important to reveal IS patients with permanently disturbed HPA axis. Patients-at-risk with high cortisol prone to delayed remote hippocampal damage should be monitored since hippocampal dysfunction may be the basis for development of post-stroke cognitive and emotional disturbances, as well as epilepsy.

A Comparative Study of Koizumi and Longa Methods of Intraluminal Filament Middle Cerebral Artery Occlusion in Rats: Early Corticosterone and Inflammatory Response in the Hippocampus and Frontal Cortex

Two classical surgical approaches for intraluminal filament middle cerebral artery occlusion (MCAO), the Longa et al. (LM) and Koizumi et al. methods (KM), are used as alternatives in preclinical studies to induce stroke in rodents. Comparisons of these MCAO models in mice showed critical differences between them along with similarities (Smith et al. 2015; Morris et al. 2016). In this study, a direct comparison of MCAO-KM and MCAO-LM in rats was performed. Three days after MCAO, infarct volume, mortality rate, neurological deficit, and weight loss were similar in these models. MCAO-LM rats showed an increase in ACTH levels, while MCAO-KM rats demonstrated elevated corticosterone and interleukin-1β in blood serum. Corticosterone accumulation was detected in the frontal cortex (FC) and the hippocampus of the MCAO-KM group. IL1β beta increased in the ipsilateral hippocampus in the MCAO-KM group and decreased in the contralateral FC of MCAO-LM rats. Differences revealed between MCAO-KM and MCAO-LM suggest that corticosterone and interleukin-1β release as well as hippocampal accumulation is more expressed in MCAO-KM rats, predisposing them to corticosterone-dependent distant neuroinflammatory hippocampal damage. The differences between two models, particularly, malfunction of the hypothalamic-pituitary-adrenal axis, should be considered in the interpretation, comparison, and translation of pre-clinical experimental results.

Copeptin and Stress

Vasopressin (AVP) and copeptin are released in equimolar amounts from the same precursor. Due to its molecular stability and countless advantages as compared with AVP, copeptin perfectly mirrors AVP presence and has progressively emerged as a reliable marker of vasopressinergic activation in response to osmotic and hemodynamic stimuli in clinical practice. Moreover, evidence highlighting the prognostic potential of copeptin in several acute diseases, where the activation of the AVP system is primarily linked to stress, as well as in psychologically stressful conditions, has progressively emerged. Furthermore, organic stressors induce a rise in copeptin levels which, although non-specific, is unrelated to plasma osmolality but proportional to their magnitude: suggesting disease severity, copeptin proved to be a reliable prognostic biomarker in acute conditions, such as sepsis, early post-surgical period, cardiovascular, cerebrovascular or pulmonary diseases, and even in critical settings. Evidence on this topic will be briefly discussed in this article.

Cortisol on Circadian Rhythm and Its Effect on Cardiovascular System

The synthesis and secretion of cortisol are controlled by the hypothalamic–pituitary–adrenal axis. Cortisol exhibits a proper 24-h circadian rhythm that affects the brain, the autonomic nervous system, the heart, and the vasculature that prepares the cardiovascular system for optimal function during these anticipated behavioral cycles. A literature search was conducted using databases such as Google Scholar, PubMed, and Scopus. Relevant search terms included “circadian rhythm and cardiovascular”, “cortisol”, “cortisol and acute coronary syndrome”, “cortisol and arrhythmias”, “cortisol and sudden cardiac death”, “cortisol and stroke”, and “cardioprotective agents”. A total of 120 articles were obtained on the basis of the above search. Lower levels of cortisol were seen at the beginning of sleep, while there was a rise towards the end of sleep, with the highest level reached at the moment the individual wakes up. In the present review, we discuss the role of 11β-hydroxysteroid dehydrogenase (11β-HSD1), which is a novel molecular target of interest for treating metabolic syndrome and type-2 diabetes mellitus. 11β-HSD1 is the major determinant of cortisol excess, and its inhibition alleviates metabolic abnormalities. The present review highlights the role of cortisol, which controls the circadian rhythm, and describes its effect on the cardiovascular system. The review provides a platform for future potential cardioprotective therapeutic agents.

Cortisol level dysregulation and its prevalence-Is it nature's alarm clock?

This review examines the stress hormone cortisol which plays an important role in regulating and supporting different bodily functions. Disruption in cortisol production has an impact on health and this review looks at a wide range of papers where cortisol has been indicated as a factor in numerous chronic conditions—especially those which are classed as “noncommunicable diseases” (NCDs). Timely detection, screening, and treatment for NCDs are vital to address the growing problem of NCDs worldwide—this would have health and socioeconomic benefits. Interestingly, many of the papers highlight the pro‐inflammatory consequences of cortisol dysregulation and its deleterious effects on the body. This is particularly relevant given the recent findings concerning COVID‐19 where pro‐inflammatory cytokines have been implicated in severe inflammation.

Combined utility of blood glucose and white blood cell in predicting outcome after acute ischemic stroke: The ENCHANTED trial

BACKGROUND

As hyperglycemia and leukocytosis individually predict poor outcome in acute ischemic stroke (AIS), we aimed to determine the significance of their combination on functional outcome and symptomatic intracerebral hemorrhage (sICH) among participants of the Enhanced Control of Hypertension and Thrombolysis Stroke Study (ENCHANTED).

METHODS

Post-hoc analyzes of the full ENCHANTED cohort, an international, multicenter, quasi-factorial, randomized, open, blinded outcome-assessed trial of low- versus standard-dose intravenous alteplase and early intensive versus standard blood pressure (BaP) lowering treatment in 4557 thrombolysis-eligible and treated AIS patients. Patients were divided into four groups according to baseline blood glucose and white blood cells (WBC) levels: A (normal glucose + WBC), B (hyperglycemia + normal WBC), C (normal glucose + high WBC), and D (hyperglycemia + high WBC). Logistic regression models were used to determine associations of each group and poor functional outcome (modified Rankin scale scores 2-6) at 90 days and sICH within 48 h, adjusted for confounders. Quality of model fit was examined with Akaike information classification (AIC), Bayesian information classification (BIC), and likelihood ratio test.

RESULTS

Of 4181 AIS patients included in analyzes, and with group A as the reference, an increasing odds of poor functional outcome was evident across groups B (odds ratio [OR] 1.38, 95 % confidence interval [CI] 1.17-1.63), C (OR 1.26, 95 %CI 0.99-1.60), and D (OR 2.26, 95 %CI 1.79-2.85) (P trend <0.001). Group D patients also had a higher rate of sICH (P trend <0.05). The model fit with the combination of blood glucose and WBC was better than models of their individual components.

CONCLUSIONS

Using a combination of blood glucose and WBC provides strong prognostic significance than either alone in thrombolyzed AIS patients.

Exploring Associations Between a Biological Marker of Chronic Stress and Reported Depression and Anxiety in People With Aphasia

Purpose Living with the communication impairment of aphasia can be stressful. Chronic stress, depression, and anxiety are intimately linked, may be more pervasive in people with poststroke aphasia than the general population, and may influence cognitive function and treatment outcomes. In this project, we explored the psychological constructs of depression and anxiety and their associations with a biomarker measure of chronic stress in people with aphasia. Method Fifty-seven participants with aphasia completed measures of depression and anxiety and provided a hair sample from which to extract the stress hormone cortisol. Pearson product-moment correlational analyses were used to identify associations between depression, anxiety, and long-term level of cortisol via hair sample. Results While cortisol level was not associated with depression and anxiety across this sample of people with aphasia, a post hoc analysis showed a significant, positive correlation between a subset of participants with moderate and higher levels of depression and elevated cortisol level. Conclusions Chronic stress, depression, and anxiety have been little explored in people with aphasia to date, yet they are associated with future health consequences and impaired cognitive function, motivating further research as well as consideration of these factors in aphasia rehabilitation.

Vasopressin and Copeptin in health and disease

Arginine Vasopressin (AVP) and copeptin derive from the same precursor molecule. Due to the equimolar secretion, copeptin responds as rapidly as AVP to osmotic, hemodynamic and unspecific stress-related stimuli and both peptides show a very strong correlation. The physiological functions of AVP are homeostasis of fluid balance, vascular tonus and regulation of the endocrine stress response. In contrast, the exact function of copeptin remains unknown. Since copeptin, in contrast to AVP, can easily be measured with a sandwich immunoassay, its main function so far that it indirectly indicates the amount of AVP in the circulation. Copeptin has emerged as a useful measure in different diseases. On one hand, through its characteristics as a marker of stress, it provides a unique measure of the individual stress burden. As such, it is a prognostic marker in different acute diseases such as ischemic stroke or myocardial infarction. On the other side, it has emerged as a promising marker in the diagnosis of AVP-dependent fluid disorders. Copeptin reliably differentiates various entities of the polyuria polydipsia syndrome; baseline levels >20 pmol/L without prior fluid deprivation identify patients with nephrogenic diabetes insipidus, whereas levels measured upon osmotic stimulation with hypertonic saline or upon non-osmotic stimulation with arginine differentiate primary polydipsia from central diabetes insipidus. In patients with hyponatremia, low levels of copeptin together with low urine osmolality identify patients with primary polydipsia, but copeptin levels overlap in all other causes of hyponatremia, limiting its diagnostic use in hyponatremia. Copeptin has also been put forward as predictive marker for autosomal dominant polycystic kidney disease and for diabetes mellitus, but more studies are needed to confirm these findings.

Combined utility of white blood cell count and blood glucose for predicting in-hospital outcomes in acute ischemic stroke

Background

High white blood cell (WBC) count and high blood glucose level are risk factors for mortality and pneumonia after acute ischemic stroke (AIS). We investigated the combined effect of high WBC count and high blood glucose level on hospital admission and in-hospital mortality and pneumonia in acute AIS patients.

Methods

A total of 3124 AIS patients enrolled from December 2013 to May 2014 across 22 hospitals in Suzhou city were included in the present study. We divided patients into four groups according to their level of WBC count and blood glucose: NWNG (normal WBC count and normal glucose), NWHG (normal WBC count and higher glucose), HWNG (higher WBC count and normal glucose), and HWHG (higher WBC count and higher glucose). Cox proportional hazard model and logistic regression model were used to estimate the combined effect of WBC count and blood glucose on all-cause in-hospital mortality and pneumonia in AIS patients.

Results

HWHG was associated with a 2.22-fold increase in the risk of in-hospital mortality in comparison to NWNG (adjusted hazard ratio [HR] 2.22; 95% confidence interval [CI], 1.21–4.07; P trend = 0.003). The risk of pneumonia was significantly higher in patients with HWHG compared to those with NWNG (adjusted odds ratio [OR] 2.61; 95% CI, 1.66–4.10; P trend < 0.001). The C-statistic for the combined WBC count and blood glucose was higher than WBC count or blood glucose alone for prediction of in-hospital mortality and pneumonia (all p < 0.01).

Conclusions

High WBC count combined with high blood glucose level at admission was independently associated with in-hospital mortality and pneumonia in AIS patients. Moreover, the combination of WBC count and blood glucose level appeared to be a better predictor than WBC count or blood glucose alone.

Electronic supplementary material

The online version of this article (10.1186/s12974-019-1422-7) contains supplementary material, which is available to authorized users.

Breaking up sitting time after stroke (BUST-stroke)

OBJECTIVES

People with stroke sit for long periods each day, which may compromise blood glucose control and increase risk of recurrent stroke. Studies in other populations have found regular activity breaks have a significant immediate (within-day) positive effect on glucose metabolism. We examined the effects of breaking up uninterrupted sitting with frequent, short bouts of light-intensity physical activity in people with stroke on post-prandial plasma glucose and insulin.

METHODS

Randomized within-participant crossover trial. We included people between 3 months and 10 years post-stroke, ambulant with minimal assistance and not taking diabetic medication other than metformin. The three experimental conditions (completed in random order) were: sitting for 8 h uninterrupted, sitting with 3 min bouts of light-intensity exercise while standing every 30 min, or sitting with 3 min of walking every 30 min. Meals were standardized and bloods were collected half- to one-hourly via an intravenous cannula.

RESULTS

A total of 19 participants (9 female, mean [SD] age 68.2 [10.2]) completed the trial. The majority ( n = 12, 63%) had mild stroke symptoms (National Institutes of Stroke Scale score 0-13). There was no significant effect of experimental condition on glucose (mean [SD] positive incremental area [+iAUC] mmol·L·h-1 under the curve during sitting 42.3 [29.5], standing 47.4 [23.1], walking 44.6 [26.5], p = 0.563) or insulin (mean + iAUC pmol·L·h-1 sitting 14,161 [7,560], standing 14,043 [8,312], walking 14,008 [8,269], p = 0.987).

CONCLUSION

Frequent, short bouts of light-intensity physical activity did not have a significant effect on post-prandial plasma glucose and insulin in this sample of people with stroke. Further studies are needed to identify strategies that improve inactivity-related glucose metabolism after stroke.

Hyperglycemia Predicts Blend Sign in Patients with Intracerebral Hemorrhage

Background

Predictive values of admission blood glucose for early hematoma expansion in patients with intracranial hemorrhage (ICH) remain controversial. Blend sign is a novel image predictor for early hematoma growth that suggests presence of active bleeding. We investigated the association between hyperglycemia and blend sign in predicting early hematoma growth in ICH patients.

Material/Methods

All patients with intracranial hemorrhage were retrospectively reviewed. Clinical characteristics and radiological parameters were collected. Blood glucose was measured within 24 h after onset. CT scan results for hematoma expansion and blend sign were evaluated by 2 readers. Multivariate logistic regression analyses were applied to reveal the associations between hematoma growth and blend sign, as well as other variables.

Results

Out of 164 patients with ICH, 52 exhibited early hematoma growth and 18 of these were diagnosed with blend sign. Average blood glucose was 7.53 mmol/L among all patients. By using multivariate analyses, the time of CT scan baseline, GCS score, hematoma size, blend sign, and blood glucose were associated with hematoma expansion, whereas only hyperglycemia was associated with blend sign.

Conclusions

Admission hyperglycemia is associated with hematoma expansion in the presence of blend sign. These findings suggest that elevated blood glucose is a possible factor predicting continuous bleeding. Strategies to control blood glucose and ameliorate hematoma growth are urgently needed and will be investigated in our future studies.

Predictors of hematoma expansion predictors after intracerebral hemorrhage

Despite years of effort, intracerebral hemorrhage (ICH) remains the most devastating form of stroke with more than 40% 30-day mortality worldwide. Hematoma expansion (HE), which occurs in one third of ICH patients, is strongly predictive of worse prognosis and potentially preventable if high-risk patients were identified in the early phase of ICH. In this review, we summarize data from recent studies on HE prediction and classify those potential indicators into four categories: clinical (severity of consciousness disturbance; blood pressure; blood glucose at and after admission); laboratory (hematologic parameters of coagulation, inflammation and microvascular integrity status), radiographic (interval time from ICH onset; baseline volume, shape and density of hematoma; intraventricular hemorrhage; especially the spot sign and modified spot sign) and integrated predictors (9-point or 24-point clinical prediction algorithm and PREDICT A/B). We discuss those predictors’ underlying pathophysiology in HE and present opportunities to develop future therapeutic strategies.

Routine hematological parameters are associated with short- and long-term prognosis of patients with ischemic stroke

BACKGROUND

Previous studies indicated that some routine hematological parameters are associated with the prognosis of ischemic stroke (IS), but none of study has evaluated them simultaneously. The aim of this study was to investigate the prognostic value of routine hematological parameters in IS patients.

METHODS

Using medical record database, we retrospectively reviewed the patients with IS admitted in Gansu Province Hospital between June 2014 and July 2015. The prognostic value of routine hematological parameters on admission was analyzed using logistic regression model, receiver operating characteristic (ROC) curve analysis and Cox proportional hazards model.

RESULTS

Patients with hospital mortality had significantly higher white blood cell (WBC), neutrophil, neutrophil to lymphocyte ratio (NLR), red blood cell distribution width (RDW) and National Institutes of Health Stroke Scale (NIHSS), while their lymphocyte, monocyte, and eosinophil were significantly lower. The area under ROC curve (AUC) for eosinophil, neutrophil, WBC, RDW, NLR, monocyte, and lymphocyte were 0.74 (95% CI, 0.67-0.82), 0.76 (95% CI, 0.67-0.84), 0.72 (95% CI, 0.64-0.81), 0.65 (95% CI, 0.56-0.73), 0.76 (95% CI, 0.68-0.84), 0.67 (95% CI, 0.59-0.76), and 0.75 (95% CI, 0.67-0.83), respectively. In a multivariable logistical regression model, only WBC, NLR, and NIHSS were independently associated with hospital mortality. In a multivariable model, age, NIHSS, RDW, NLR, and eosinophil were independent prognostic factors for all-cause mortality.

CONCLUSION

Red blood cell distribution width, NLR and eosinophil are independent prognostic factors for IS.

Serum Trace Element Profiles, Prolactin, and Cortisol in Transient Ischemic Attack Patients

The primary aim of the present study was to assess the association between trace element status, brain damage biomarkers, cortisol, and prolactin levels in transient ischemic attack (TIA) patients. Ten male and 10 female TIA patients were involved in this study. Age, gender, and BMI-matched volunteers served as the respective control group. Serum samples were examined for complement components C4 and C3a, vascular endothelial growth factor (VEGF), S100B, NR2 antibodies (NR2Ab), total antioxidant status (TAS), cortisol, and prolactin. Trace element concentration in serum samples was assessed using inductively coupled plasma mass spectrometry at NexION 300D. The obtained data indicate that both male and female TIA patients were characterized by the increased C4 and prolactin concentrations. At the same time, serum VEGF levels were elevated in only men, whereas TAS values were decreased in women with TIA. Serum cortisol concentrations were significantly increased only in female TIA patients. Men and women with TIA were characterized by a 32 and 44 % decrease in serum Fe content. A two- and threefold increase in serum V content was observed in TIA females and males, respectively. Women with TIA had 60 % higher values of serum B, whereas male patients were characterized by a sevonfold increase in boron content in comparison to the control values. TIA also resulted in decreased serum Cu content in women and elevation of I, Li, Mn, Se, Zn, As, Pb, Ni, and Sr levels in men. Correlation analysis revealed a significant association between trace elements concentration and the studied parameters.

Alterations in the corticotropin-releasing hormone (CRH) neurocircuitry: Insights into post stroke functional impairments

Although it is well accepted that changes in the regulation of the hypothalamic-pituitary adrenal (HPA) axis may increase susceptibility to affective disorders in the general population, this link has been less examined in stroke patients. Yet, the bidirectional association between depression and cardiovascular disease is strong, and stress increases vulnerability to stroke. Corticotropin-releasing hormone (CRH) is the central stress hormone of the HPA axis pathway and acts by binding to CRH receptors (CRHR) 1 and 2, which are located in several stress-related brain regions. Evidence from clinical and animal studies suggests a role for CRH in the neurobiological basis of depression and ischemic brain injury. Given its importance in the regulation of the neuroendocrine, autonomic, and behavioral correlates of adaptation and maladaptation to stress, CRH is likely associated in the pathophysiology of post stroke emotional impairments. The goals of this review article are to examine the clinical and experimental data describing (1) that CRH regulates the molecular signaling brain circuit underlying anxiety- and depression-like behaviors, (2) the influence of CRH and other stress markers in the pathophysiology of post stroke emotional and cognitive impairments, and (3) context and site specific interactions of CRH and BDNF as a basis for the development of novel therapeutic targets. This review addresses how the production and release of the neuropeptide CRH within the various regions of the mesocorticolimbic system influences emotional and cognitive behaviors with a look into its role in psychiatric disorders post stroke.

Maternal high-fat diet influences stroke outcome in adult rat offspring

Diet-induced epigenetic modifications in early life could contribute to later health problem. However, it remains to be established whether high-fat diet (HFD) consumption during pregnancy and the suckling period could predispose the offspring to stroke. The present study investigated the influence of maternal HFD on stroke outcome in adult offspring. Female Sprague-Dawley rats were fed a normal diet (5.3% fat) or a HFD (25.7% fat), just before pregnancy until the end of lactation. Male offspring were fed with the control diet or the HFD after weaning, to form four groups (control offspring fed with the control diet (C/C) or the HFD (C/HFD) and offspring of fat-fed dams fed with the control diet (HFD/C) or the HFD (HFD/HFD)). The offspring received middle cerebral artery occlusion on day 120 followed by behavioral tests (neurological deficit score, staircase-reaching test and beam-traversing test), and infarct volumes were also calculated. We found that the HFD/C rats displayed larger infarct volume and aggravated functional deficits (all P<0.05), compared with the C/C rats, indicating that maternal fat-rich diet renders the brain more susceptible to the consequences of ischemic injury. Moreover, maternal HFD offspring displayed elevated glucocorticoid concentrations following stroke, and increased glucocorticoid receptor expression. In addition, adrenalectomy reversed the effects of maternal HFD on stroke outcome when corticosterone was replaced at baseline, but not ischemic, concentrations. Furthermore, expression of brain-derived neurotrophic factor (BDNF) in the ipsilateral hippocampus was decreased in the HFD/C offspring (P<0.05), compared with the C/C offspring. Taken together, maternal diet can substantially influence adult cerebrovascular health, through the programming of central BDNF expression and the hypothalamic-pituitary-adrenal axis.

The Cortisol Awakening Response in Patients with Poststroke Depression Is Blunted and Negatively Correlated with Depressive Mood

It is important to reduce poststroke depression (PSD) to improve the stroke outcomes and quality of life in stroke patients, but the underlying mechanisms of PSD are not completely understood. As many studies implicate dysregulation of hypothalamic-pituitary-adrenal axis in the etiology of major depression and stroke, we compared the cortisol awakening response (CAR) of 28 admitted PSD patients with that of 23 age-matched caregiver controls. Saliva samples for cortisol measurement were collected immediately, 15, 30, and 45 min after awakening for two consecutive days. Depressive mood status in PSD patients was determined with Beck Depression Inventory and Hamilton Depression Rating Scale. Salivary cortisol levels of PSD patients did not rise significantly at any sampling time, showing a somewhat flat curve. Caregiver controls showed significantly higher CAR at 15 and 30 min after awakening compared to PSD patients even though the two groups did not differ at awakening or 45 min after awakening. Area-under-the-curve analysis revealed a significant negative correlation between the CAR and the degree of depression in PSD patients. Thus, our findings suggest that poststroke depression is closely related with dysfunctional HPA axis indicated by blunted CAR.

Neuroendocrine hormones as prognostic biomarkers in the setting of acute stroke: overcoming the major hurdles

Stroke represents one of the major causes of disability and mortality worldwide and prediction of outcome represents a challenge for both clinicians and researchers. In the past years, many blood markers have been associated with stroke outcome but despite this evidence, no biomarker is routinely used in stroke management. In this review, we focus on markers of the neuroendocrine system, which represent potential candidates to be implemented in clinical practice. Moreover, we present a systematic review and literature-based meta-analysis for copeptin, a new biomarker of the hypothalamo-pituitary-adrenal axis that has shown additional predictive value over clinical information in a large prospective study. The meta-analysis of the included 7 studies, with more than 2000 patients, reinforced its association with poor outcome (pooled odds ratio: 2.474 [1.678-3.268]) and mortality (pooled OR: 2.569 [1.642-3.495]). We further review the current situation of the topic and next steps to implement these tools by clinicians.

Hospitalization and cognitive decline: Can the nature of the relationship be deciphered?

BACKGROUND

Evidence for a relationship between hospitalization and incident cognitive decline exists mainly in the literature focusing on critical care hospitalization. Recent studies, however, have also found an association between noncritical care hospitalization and the development of cognitive decline.

OBJECTIVE

This article will review the literature pertaining to hospitalization and cognitive decline, including hospitalizations for both critical and noncritical care, and in medical and surgical patients. The article will also explore the various factors that have been implicated in the development of cognitive decline and dementia.

METHODS

Review of the literature was completed using PubMed and Medline search programs.

RESULTS

Several articles supporting evidence for the association between hospitalization and cognitive decline are available. Evidence for potential mediating factors also does exist.

CONCLUSIONS

There is evidence to support an association between hospitalization and development of cognitive decline. Factors that could mediate this association include, but may not be limited to, delirium, medications, stress, and depression. There is a need for further research in this area in order to better understand the underlying pathophysiology involved in the development of cognitive decline and dementia and to determine if preventive measures might be beneficial in decreasing risk for cognitive decline for patients who are hospitalized.

Cortisol levels and the severity and outcomes of acute stroke: a systematic review

Studies in non-stroke patients have shown an association between dysregulation of the hypothalamic-pituitary-adrenal axis and morbidity and mortality. We conducted a systematic review to evaluate cortisol levels in acute stroke and their associations with outcome. We searched MEDLINE and EMBASE for articles up to April 2013 and PsychINFO for articles up to July 2013, using the keywords "cortisol" and "stroke" and associated terms or synonyms. We included studies published in peer-reviewed journals that recruited 10 or more participants and measured cortisol at least once in the first year following stroke. Data were extracted regarding cortisol levels, including changes over time and their relationship to stroke severity, and outcome. Of 11,240 abstracts, 101 full texts were obtained and 48 fulfilled our inclusion criteria. Cortisol levels were high in the first week after stroke in the majority of studies (26 studies, n = 1,340). Higher cortisol was associated with dependency (8/11 studies, n = 822), delirium (5/6 studies, n = 269) depression (3/5 studies n = 117) and mortality (8/10 studies, n = 856). Five studies adjusted for stroke severity; one found an association between higher cortisol and dependency, and three found an association between higher cortisol and mortality. Cortisol levels are high for at least 7 days after stroke. Elevated cortisol after stroke is associated with dependency, morbidity, and mortality; however, there is insufficient evidence to conclude that these relationships are independent of stroke severity.

The role of neuroendocrine pathways in prognosis after stroke

A number of neuroendocrine changes have been described after stroke, which may serve adaptive or deleterious functions. The neuroendocrine changes include activation of the hypothalamo-pituitary-adrenal axis, sympathetic nervous system and alterations of several hormonal levels. Alterations of the HPA axis, increased catecholamines, natriuretic peptides and, decreased melatonin and IGF-1 levels are associated with poor post-stroke outcome, although there is no definitive proof of causality. Therefore, it remains to be established whether alteration of neuroendocrine responses could be used as a potential therapeutic target to improve stroke outcome. This article gives an overview of the major neuroendocrine pathways altered by stroke and highlights their potential for clinical use and further neurotherapeutic development by summarizing the evidence for their association with stroke outcome including functional outcome, post-stroke infection, delirium, depression and stroke-related myocardial injury.

Predictors of early mortality in patients with ischemic stroke

Accurate predictors of early outcome in stroke patients have a number of important applications, such as introducing secondary prevention strategies, supporting treatment decisions or designing randomized clinical trials. Surprisingly, a generally accepted, reliable and well-validated mortality-prediction model is still unavailable. This review outlines the most important predictors of in-hospital mortality that could be assessed at admission to hospital emergency room within 24 h of ischemic stroke onset. A number of factors are discussed such as nonmodifiable factors (e.g., age, gender and genetic factors); type of stroke and its severity - measured by different clinical score scales; predictive models; laboratory markers; special neuroradiological and neurophysiological tests; and comorbid conditions at admission and quality of hospital care.

Changes in Hypothalamus–Pituitary–Adrenal Axis Following Transient Ischemic Attack

Acute brain ischemia caused by transient ischemic attack initiates a complex sequence of events in the central nervous system and hypothalamic–pituitary–adrenal (HPA) axis which may ultimately culminate in neuronal and cell damage. The brain is highly susceptible to ischemia and in response to stress shows changes in morphology and chemistry that are largely reversible. These responses are known to modify the function of the HPA axis, but their mechanisms are not yet clear. Duration and size of the HPA axis activation are regulated by corticotropin-releasing hormone, vasopressin (AVP), and glucocorticoids, including cortisol. Numerous studies suggest that activation of these hormones following brain ischemia can result in neurohormonal dysfunction that can exacerbate long-term prognosis following stroke. These studies represent evidence that changes in the HPA axis play an important role in brain ischemia.

Cortisol as a prognostic marker of short-term outcome in chinese patients with acute ischemic stroke

Background

Early prediction of outcome is important for allocation of therapeutic strategies. Endocrine alterations of the hypothalamus–pituitary–axis are one of the first stress-induced alterations after cerebral ischemia. We therefore evaluated the prognostic value of serum cortisol in Chinese patients with an acute ischemic stroke.

Methods

In a prospective observational study, serum cortisol was measured using a solid-phase, competitive chemiluminescent enzyme immunoassay on admission in serum of 226 consecutive Chinese patients with an acute ischemic stroke. The prognostic value of serum cortisol to predict the functional outcome, mortality within 90 days, was compared with clinical variables (e.g., advanced age and the National Institutes of Health Stroke Scale [NHISS] score) and with other known predictors.

Results

Patients with a poor outcome and nonsurvivors had significantly increased serum cortisol levels on admission (P<0.0001, P<0.0001). There was a positive correlation between levels of cortisol and the NIHSS (r = 0.298, P<0.0001), glucose levels (r = 0.324, P<0.0001) and infarct volume (r = 0.328, P<0.0001). Cortisol was an independent prognostic marker of functional outcome and death [odds ratio 3.44 (2.58–6.23) and 4.21 (1.89–9.24), respectively, P<0.0001 for both, adjusted for age, the NIHSS and other predictors] in patients with ischemic stroke. In receiver operating characteristic curve analysis, cortisol could improve the NIHSS score in predicting short-term functional outcome (Area under the curve [AUC] of the combined model, 0.87; 95% CI, 0.82–0.92; P = 0.01) and mortality (AUC of the combined model, 0.90; 95% CI, 0.84–0.95; P = 0.01).

Conclusion

Cortisol can be seen as an independent short-term prognostic marker of functional outcome and death in Chinese patients with acute ischemic stroke even after correcting confounding factors. Combined model can add significant additional predictive information to the clinical score of the NIHSS.

Prognostic value of dehydroepiandrosterone-sulfate and other parameters of adrenal function in acute ischemic stroke

Background and Purpose

Acute stroke has a high morbidity and mortality. We evaluated the predictive value of adrenal function testing in acute ischemic stroke.

Methods

In a cohort of 231 acute ischemic stroke patients, we measured dehydroepiandrosterone (DHEA), DHEA-Sulfate (DHEAS), cortisol at baseline and 30 minutes after stimulation with 1 ug ACTH. Delta cortisol, the amount of rise in the 1 ug ACTH-test, was calculated. Primary endpoint was poor functional outcome defined as modified Rankin scale 3–6 after 1 year. Secondary endpoint was nonsurvival after 1 year.

Results

Logistic regression analysis showed that DHEAS (OR 1.21, 95% CI 1.01–1.49), but not DHEA (OR 1.01, 95% CI 0.99–1.04), was predictive for adverse functional outcome. Neither DHEA (OR 0.99, 95% CI 0.96–1.03) nor DHEAS (OR 1.10, 95% CI 0.82–1.44) were associated with mortality. Baseline and stimulated cortisol were predictive for mortality (OR 1.41, 95% CI 1.20–1.71; 1.35, 95% CI 1.15–1.60), but only basal cortisol for functional outcome (OR 1.20, 95% CI 1.04–1.38). Delta cortisol was not predictive for functional outcome (OR 0.86, 95% CI 0.71–1.05) or mortality (OR 0.92, 95% CI 0.72–1.17). The ratios cortisol/DHEA and cortisol/DHEAS discriminated between favorable outcome and nonsurvival (both p<0.0001) and between unfavorable outcome and nonsurvival (p = 0.0071 and 0.0029), but are not independent predictors for functional outcome or mortality in multivariate analysis (adjusted OR for functional outcome for both 1.0 (95% CI 0.99–1.0), adjusted OR for mortality for both 1.0 (95% CI 0.99–1.0 and 1.0–1.01, respectively)).

Conclusion

DHEAS and the cortisol/DHEAS ratio predicts functional outcome 1 year after stroke whereas cortisol levels predict functional outcome and mortality.

Trial Registration

ClinicalTrials.gov NCT00390962 (Retrospective analysis of this cohort).

Effect of interval training program on white blood cell count in the management of hypertension: A randomized controlled study

OBJECTIVE

Elevated white blood cell (WBC) count is considered to be prospectively and positively associated with cardiovascular diseases, particularly hypertension. Also, the positive role of exercise in the management of hypertension has been well and long established. However the relationship between WBC count and hypertensive management particularly in the nonpharmacological technique is ambiguous and unclear. Therefore the purpose of the present study was to determine the effect of interval training program on WBC count and cardiovascular parameters in male hypertensive patients.

MATERIALS AND METHODS

A total of 245 male patients with mild to moderate (systolic blood pressure (SBP) between 140 mmHg and 179 mmHg and diastolic blood pressure (DBP) between 90 mmHg and 109 mmHg) essential hypertension were age matched and grouped into experimental and control groups. The experimental (n=140; 58.90±7.35 years) group involved in an 8-week interval training (60-79% HR max reserve) program of between 45 minutes to 60 minutes, while the age-matched controls hypertensive (n=105; 58.27±6.24 years) group remain sedentary during this period. Cardiovascular parameters (SBP, DBP, and VO(2) max) and WBC count were assessed. Student's t and Pearson correlation tests were used in data analysis.

RESULTS

Findings of the study revealed a significant effect of the interval training program on VO2max, SBP, and DBP and WBC count at P<0.05 and VO2max is negatively related to the WBC count (r=-0.339) at P<0.01.

CONCLUSIONS

It was concluded that the interval training program is an effective adjunct nonpharmacological management of hypertension and the therapeutic effect of exercise programs may be mediated through suppression of inflammatory (WBC count) reaction.

Serum albumin as a determinant of cortisol release in patients with acute ischemic stroke

OBJECTIVE

Animal studies demonstrated that protein malnutrition increases pituitary-adrenorcortical activity and leads to excessive cortisol release. The aim of our study was to determine the association between serum albumin and cortisol level in patients with acute ischemic stroke.

METHODS

Fifty-nine patients with first-ever ischemic stroke were included. Serum albumin level was measured within 36 h after stroke symptoms onset. Serum cortisol was measured between 36 and 72 h after stroke onset at 6 a.m., 10 a.m., 6 p.m. and 10 p.m.

RESULTS

The patients in upper tertile of serum albumin had significantly lower cortisol level measured at 6 a.m. (median with interquartiles: 549.0 [430.4-667.7] nmol/L vs 590.4 [482.8-918.7] nmol/L, P=0.047) and 10 a.m. (402.8 [344.9-510.4] nmol/L vs 634.6 [482.8-827.7] nmol/L, P<0.01) than patients in lower and middle tertiles. On logistic regression analysis adjusted for age and stroke severity, patients in lower and middle tertile of serum albumin had about 7-times higher risk of hypercortisolemia than patients in upper tertile (P<0.01).

CONCLUSIONS

Low serum albumin level in patients with ischemic stroke is associated with higher serum cortisol level and predisposes to hypercortisolemia.

Plasma α-melanocyte stimulating hormone predicts outcome in ischemic stroke

BACKGROUND AND PURPOSE

α-Melanocyte stimulating hormone (α-MSH) is an endogenously produced neuropeptide derived from the same precursor as adrenocorticotropic hormone. α-MSH has profound immunomodulatory properties and may also be neuroprotective. Nothing is known about α-MSH and changes in its plasma concentrations in patients with acute ischemic stroke.

METHODS

In this prospective observational study, plasma concentrations of α-MSH, adrenocorticotropic hormone, cortisol, and interleukin 6 were assessed longitudinally over the course of 1 year after stroke onset in 111 patients. Logistic regression was used to the effect of initial plasma α-MSH, adrenocorticotropic hormone, cortisol, and interleukin 6 on long-term outcome.

RESULTS

There was an early decrease in plasma α-MSH in patients with severe stroke (National Institutes of Health Stroke Scale≥17) that normalized over the course of the year; these same patients evidenced elevations in plasma cortisol and interleukin 6. Higher initial plasma α-MSH, but not adrenocorticotropic hormone, cortisol, or interleukin 6, was independently predictive of good long-term outcome.

CONCLUSIONS

This research is the first to study endogenous changes in plasma α-MSH after stroke. The independent effect of early plasma α-MSH on stroke outcome, as well as a growing body of experimental data demonstrating improved stroke outcome with exogenous α-MSH administration, suggests a potential therapeutic role for α-MSH in the treatment of stroke.

Inflammatory and neuroendocrine biomarkers of prognosis after ischemic stroke

Stroke is the third leading cause of mortality in the USA and one of the leading causes of severe morbidity. It is important to provide stroke patients and physicians with the most accurate prognostic information to optimize care and allocation of healthcare resources. Reliable prognostic markers available during the initial phase after acute stroke may aid clinical decision-making. Several interesting candidate biomarkers have been studied to address prognostic questions; this article will focus on selected inflammatory and neuroendocrine markers. The utility of a biomarker is defined by its ability to improve clinical decision-making and add timely information beyond that readily available from clinical examination and routine imaging. This aim has not been completely achieved yet for any biomarkers, but promising data are available and further studies are ongoing.

Effects of glucose level on early and long-term mortality after intracerebral haemorrhage: the Acute Brain Bleeding Analysis Study

AIMS/HYPOTHESIS

Admission hyperglycaemia is associated with a poor outcome in patients with ischaemic stroke. However, its prognostic effects after intracerebral haemorrhage (ICH) are still unclear.

METHODS

We prospectively enrolled patients with ICH at 33 centres in Korea between October 2002 and March 2004. A total of 1,387 patients who had ICH and underwent brain computed tomography within 48 h of symptom onset were included in the study (n = 1,387). Clinical information and radiological findings were collected at admission. Glucose levels were examined in relation to early (up to 30 days after ictus) and long-term (after 30 days) mortality rates using Cox regression analysis. To eliminate short-term effects, long-term mortality rate analysis was performed on surviving patients for more than 30 days.

RESULTS

The long-term mortality rate was 21.1% after a mean follow-up of 434.3 +/- 223.2 days and was found to increase significantly with glucose quartile (p < 0.001). Admission glucose level was an independent risk factor for early mortality (per mmol/l; adjusted HR 1.10 [95% CI 1.01-1.19]), but not for long-term mortality. Moreover, when analysis was restricted to patients without diabetes, glucose level was found to be an independent risk factor for post-ICH mortality (n = 1,119; adjusted HR 1.10 [95% CI 1.03-1.17]) and had marginal significance for early (p = 0.053) and long-term mortality (p = 0.09).

CONCLUSIONS/INTERPRETATION

We found that admission glucose levels were associated with early mortality after ICH. In patients without diabetes, admission glucose levels were associated with long-term mortality. We therefore suggest that intensive lowering of glucose level should be further investigated in ICH patients.

Depression and the cardiovascular system: increasing evidence of a link and therapeutic implications

This review explores the epidemiological evidence for the relationship between depression and cardiovascular disease from a mechanistic standpoint. It is important to examine the biological, behavioral and social mechanisms to improve outcomes for depressed cardiac patients. A number of plausible biobehavioral mechanisms linking depression and cardiovascular disease have been identified. Tricyclic antidepressants have various effects on the cardiovascular system, while selective serotonin reuptake inhibitors are not associated with adverse cardiac effects and should, therefore, be the preferred choice for the treatment of most patients with comorbid depression and cardiovascular disease.

Vulnerability to stroke: implications of perinatal programming of the hypothalamic-pituitary-adrenal axis

Chronic stress is capable of exacerbating each major, modifiable, endogenous risk factor for cerebrovascular and cardiovascular disease. Indeed, exposure to stress can increase both the incidence and severity of stroke, presumably through activation of the hypothalamic-pituitary-adrenal (HPA) axis. Now that characterization of the mechanisms underlying epigenetic programming of the HPA axis is well underway, there has been renewed interest in examining the role of early environment on the evolution of health conditions across the entire lifespan. Indeed, neonatal manipulations in rodents that reduce stress responsivity, and subsequent life-time exposure to glucocorticoids, are associated with a reduction in the development of neuroendocrine, neuroanatomical, and cognitive dysfunctions that typically progress with age. Although improved day to day regulation of the HPA axis also may be accompanied by a decrease in stroke risk, evidence from rodent studies suggest that an associated cost could be increased susceptibility to inflammation and neuronal death in the event that a stroke does occur and the individual is exposed to persistently elevated corticosteroids. Given its importance in regulation of health and disease states, any long-term modulation of the HPA axis is likely to be associated with both benefits and potential risks. The goals of this review article are to examine (1) the clinical and experimental data suggesting that neonatal experiences can shape HPA axis regulation, (2) the influence of stress and the HPA axis on stroke incidence and severity, and (3) the potential for neonatal programming of the HPA axis to impact adult cerebrovascular health.

Modern approaches to understanding stress and disease susceptibility: A review with special emphasis on respiratory disease

Studies in animals and humans link both physical and psychological stress with an increased incidence and severity of respiratory infections. For this manuscript we define stress as the physiological responses an individual undergoes while adjusting to a continually changing environment. It is known that stressors of various types (psychological/physical) can alter the physiological levels of certain hormones, chemokines and cytokines. These alterations send information to the central nervous system to take necessary action which then sends messages to appropriate organs/tissues/cells to respond. These messages can either activate or suppress the immune system as needed and failure to compensate for this by the body can lead to serious health-related problems. Little is known how stress affects disease susceptibility, yet understanding this mechanism is important for developing effective treatments, and for improving health and food quality. The current review focuses on (a) the effects of psychological stressors in humans and animals, (b) various methodologies employed to understand stress responses and their outcomes, and (c) the current status of the attempts to correlate stress and disease with respiratory disease as model system. The methodologies included in this review span traditional epidemiological, behavioral and immunological studies to current high throughput genomic, proteomic, metabolomic/metabonomic approaches. With the advent of various newer omics and bioinformatics methodologies we postulate that it will become feasible to understand the mechanisms through which stress can influence disease onset. Although the literature in this area is limited because of the infancy of this research area, the objective of this review is to illustrate the power of new approaches to address complex biological questions. These new approaches will also aid in our understanding how these processes are related to the dynamics and kinetics of changes in expression of multiple genes at various levels.

Monocytes Are Major Players in the Prognosis and Risk of Infection After Acute Stroke

Background and Purpose— Monocytes participate in adaptive and innate immune responses. Monocyte numbers increase in patients with stroke associated infection (SAI) or severe stroke. Whether changes in monocytes are related to specific effects, or simply mark brain damage, remains unsettled.

Methods— We used flow cytometry in 45 consecutive strokes and 12 healthy controls to assess the time course of monocytes, their phenotype, and the production of cytokines after stimulation. Cortisol, TNF-α, IFN-γ, and IL-10 were measured in serum and metanephrine in plasma. The effects of humoral and cellular parameters on the risk of SAI and poor outcome were tested in multivariate analyses adjusted for confounders (NIHSS score, age, and tube feeding).

Results— Surface expression of human leukocyte antigen-DR, Toll-like receptor-2, and production of TNF-α in monocytes were independently associated with stroke. Distinct immune mechanisms were related with functional outcome and the risk of SAI; the signature of SAI included an increase of cortisol, metanephrine, and IL-10 in serum, and reduced production of TNF-α in monocytes; poor outcome was associated with increased expression of Toll-like receptor-4 in monocytes (OR, 9.61; 95% CI, 1.27–72.47). SAI did not predict poor outcome (OR, 5.63; 95% CI, 0.45–70.42; P =0.18).

Conclusions— In human stroke, poor outcome is associated to innate responses mediated by Toll-like receptor-4 in monocytes. SAI may result from the immunosuppressive and antiinflammatory effects of corticoids, catecholamines, IL-10, and deactivated monocytes. Early treated SAI does not contribute significantly to additional brain damage. These findings encourage the exploration of strategies aimed to inhibit Toll-like receptor-4 signaling in acute stroke.

Early changes in physiological variables after stroke

Several aspects of physiology, notably blood pressure, body temperature, blood glucose, and blood oxygen saturation, may be altered after an ischemic stroke and intracerebral hemorrhage. Generally, blood pressure and temperature rise acutely after a stroke, before returning to normal. Blood glucose and oxygen levels may be abnormal in individuals, but they do not follow a set pattern. Several aspects of these physiological alterations remain unclear, including their principal determinants - whether they genuinely affect prognosis (as opposed to merely representing underlying processes such as inflammation or a stress response), whether these effects are adaptive or maladaptive, whether the effects are specific to certain subgroups (e.g. lacunar stroke) and whether modifying physiology also modifies its prognostic effect. Hypertension and hyperglycemia may be helpful or harmful, depending on the perfusion status after an ischemic stroke; the therapeutic response to their lowering may be correspondingly variable. Hypothermia may provide benefits, in addition to preventing harm through protection from hyperthermia. Hypoxia is harmful, but normobaric hyperoxia is unhelpful or even harmful in normoxic patients. Hyperbaric hyperoxia, however, may be beneficial, though this remains unproven. The above-mentioned uncertainties necessitate generally conservative measures for physiology management, although there are notably specific recommendations for thrombolysis-eligible patients. Stroke unit care is associated with better outcome, possibly through better management of poststroke physiology. Stroke units can also facilitate research to clarify the relationship between physiology and prognosis, and to subsequently clarify management guidelines.

Effects of admission glucose level on mortality after subarachnoid hemorrhage: a comparison between short-term and long-term mortality

BACKGROUND

Admission hyperglycemia is associated with poor functional outcomes and risk of death in nondiabetic patients with acute ischemic stroke. However, there is still some debate about the effects of hyperglycemia in subarachnoid hemorrhage (SAH) patients. The purpose of this study was to assess whether the admission glucose level in patients with SAH is associated with short- and/or long-term mortality.

METHODS

A consecutive data set of SAH patients without diabetes was obtained from a prospective multicenter cohort of hemorrhagic stroke patients. The effects of glucose level were examined in relation to short- (30 days) or long-term mortality using Cox regression analysis. To eliminate the short-term effects of glucose level, the long-term effects were analyzed in the patients who survived for more than 30 days.

RESULTS

A total of 803 SAH patients were followed up in this study. The 30-day and final mortalities were 7.6% and 12.0%, respectively. Throughout the entire follow-up period, glucose level was found to be significantly associated with final mortality after adjusting for potential confounders (adjusted HR, 1.10; 95% CI, 1.01 to 1.19). Moreover, glucose level was found to be associated with short-term mortality (adjusted HR, 1.15; 95% CI, 1.05 to 1.27), but not with long-term mortality (adjusted HR, 0.97; 95% CI, 0.82 to 1.14).

CONCLUSIONS

We demonstrated that admission hyperglycemia has a harmful effect on short-term mortality, but not with long-term mortality in SAH patients without diabetes. Our results may be used as further evidence to support a hypothesis of harmful effects of hyperglycemia in SAH patients.

Platelet and endothelial activity in comorbid major depression and coronary artery disease patients treated with citalopram: the Canadian Cardiac Randomized Evaluation of Antidepressant and Psychotherapy Efficacy Trial (CREATE) biomarker sub-study

BACKGROUND AND PURPOSE

Major depression is an independent risk factor for increased morbidity and mortality in patients with coronary artery disease (CAD). Increased platelet activity and vascular endothelial dysfunction are possible pathways through which depression may increase cardiovascular risk. Citalopram exhibits strong selective inhibition of human platelet activation, but little is known about its effects on vascular endothelium. We assessed whether treatment of depressed CAD patients with citalopram alters platelet/endothelial biomarkers. The study was performed within the framework of the CREATE trial.

METHODS

We assessed the effect of citalopram on P-selectin, beta-thromboglobulin (betaTG), soluble intercellular cell adhesion molecule-1 (sICAM-1), and total nitric oxide (tNO). Plasma samples were obtained at baseline and week 12 from subjects randomized to citalopram 20-40 mg daily (n = 36), or placebo (n = 21). Anticoagulants, aspirin, and clopidogrel were permitted.

RESULTS

Treatment with citalopram was associated with greater increase in tNO over 12 weeks compared to placebo (P = 0.005). There were no differences for the other biomarkers such as P-selectin (P = 0.70), betaTG (P = 0.46) and ICAM (P = 0.59).

CONCLUSION

Treatment with citalopram for 12 weeks in depressed CAD patients is associated with enhanced production of nitric oxide despite the co-administration of commonly prescribed anti-platelet regimens including aspirin and clopidogrel. Clinical implications of these findings are unclear, but improved endothelial function is implied by the increased NO production, suggesting that citalopram may be of particular benefit for patients with comorbid depression and vascular disease including CAD, stroke, peripheral artery disease, and diabetes.

Higher morning serum cortisol level predicts increased fibrinogen but not shortened APTT

BACKGROUND

There is emerging evidence that serum cortisol might be independently associated with prothrombotic activity, suggesting that increased cortisol levels might finally contribute to the pathogenesis of atherosclerotic disorders. Since hypercoagulability is principally sustained by either defective naturally occurring anticoagulant mechanisms or to heightened coagulation factors, most of which are cumulatively explored by the activated partial thromboplastin time (APTT), the present investigation was designed to asses the potential relationship between morning serum cortisol, APTT and fibrinogen in a general population of healthy outpatients.

METHODS

We performed a retrospective analysis on the database of our Laboratory Information System to retrieve results of morning serum cortisol, APTT and fibrinogen, which were performed on consecutive outpatients referred by general practitioners for routine blood testing over the previous 2 years.

RESULTS

Cumulative results for morning serum cortisol, APTT and fibrinogen were retrieved for 302 adults >35 years old (M/F = 61/90; age 49 +/- 13 years; range 35-79). A statistically significant increased concentration of fibrinogen was observed in subject with morning serum cortisol values above the upper limit of the reference range (P < 0.001), whereas the concentration of APTT was not significantly different between the two subgroups of subjects with normal and increased morning serum cortisol (P = 0.432). This difference remained statistically significant even after adjusting for age and sex. In multivariable linear regression analysis, the concentration of fibrinogen, but not the value of the APTT, was significantly associated with morning serum cortisol.

CONCLUSIONS

The results of this retrospective investigation confirm that baseline cortisol levels might predict higher fibrinogen in the general population. This potential biological interrelationship deserves further scrutiny for the potential implications on prediction and prevention of the cardiovascular risk.

The time course and determinants of temperature within the first 48 h after ischaemic stroke

BACKGROUND AND PURPOSE

Previous research has attempted to analyze the relationship between post-stroke hyperthermia and prognosis. These analyses have been hindered by a lack of information about the time course and determinants of temperature change after stroke.

METHODS

Serial temperatures were measured until 48 h after ischaemic stroke in a prospectively recruited cohort. Potential determinants of temperature, including stroke severity [measured using the National Institutes of Health Stroke Scale (NIHSS)], infection and paracetamol use were recorded. Mixed-effects models were used to model serial temperature measurements over time, adjusted for significant determinants.

RESULTS

In 155 patients the mean temperature rose from 36.5 degrees C at the time of stroke to 36.7 degrees C approximately 36 h later. The factors with significant multivariable associations with serial temperatures were: first- and second-order time components, infection, paracetamol administration and the interaction between stroke severity (NIHSS > or =6) and time (all p < 0.1). Patients with admission NIHSS > or =6 had a mean temperature rise of 0.35 degrees C during the first 36 h after stroke, compared with a rise of 0.17 degrees C in those with NIHSS < or =5.

CONCLUSIONS

Temperature spontaneously rises during the first 36 h after stroke, particularly after severer stroke and in the presence of infection.