Cigarette smoking. A risk factor for hemorrhagic and nonhemorrhagic stroke

Cardiopulmonary Impact of Electronic Cigarettes and Vaping Products: A Scientific Statement From the American Heart Association

Vaping and electronic cigarette (e-cigarette) use have grown exponentially in the past decade, particularly among youth and young adults. Cigarette smoking is a risk factor for both cardiovascular and pulmonary disease. Because of their more limited ingredients and the absence of combustion, e-cigarettes and vaping products are often touted as safer alternative and potential tobacco-cessation products. The outbreak of e-cigarette or vaping product use-associated lung injury in the United States in 2019, which led to >2800 hospitalizations, highlighted the risks of e-cigarettes and vaping products. Currently, all e-cigarettes are regulated as tobacco products and thus do not undergo the premarket animal and human safety studies required of a drug product or medical device. Because youth prevalence of e-cigarette and vaping product use was as high as 27.5% in high school students in 2019 in the United States, it is critical to assess the short-term and long-term health effects of these products, as well as the development of interventional and public health efforts to reduce youth use. The objectives of this scientific statement are (1) to describe and discuss e-cigarettes and vaping products use patterns among youth and adults; (2) to identify harmful and potentially harmful constituents in vaping aerosols; (3) to critically assess the molecular, animal, and clinical evidence on the acute and chronic cardiovascular and pulmonary risks of e-cigarette and vaping products use; (4) to describe the current evidence of e-cigarettes and vaping products as potential tobacco-cessation products; and (5) to summarize current public health and regulatory efforts of e-cigarettes and vaping products. It is timely, therefore, to review the short-term and especially the long-term implications of e-cigarettes and vaping products on cardiopulmonary health. Early molecular and clinical evidence suggests various acute physiological effects from electronic nicotine delivery systems, particularly those containing nicotine. Additional clinical and animal-exposure model research is critically needed as the use of these products continues to grow.

Comparative assessment of in vitro BBB tight junction integrity following exposure to cigarette smoke and e-cigarette vapor: a quantitative evaluation of the protective effects of metformin using small-molecular-weight paracellular markers

Background

The blood–brain barrier (BBB) plays a critical role in protecting the central nervous system (CNS) from blood-borne agents and potentially harmful xenobiotics. Our group’s previous data has shown that tobacco smoke (TS) and electronic cigarettes (EC) affect the BBB integrity, increase stroke incidence, and are considered a risk factor for multiple CNS disorders. Metformin was also found to abrogate the adverse effects of TS and EC.

Methods

We used sucrose and mannitol as paracellular markers to quantitatively assess TS and EC’s impact on the BBB in-vitro. Specifically, we used a quantitative platform to determine the harmful effects of smoking on the BBB and study the protective effect of metformin. Using a transwell system and iPSCs-derived BMECs, we assessed TS and EC’s effect on sucrose and mannitol permeability with and without metformin pre-treatment at different time points. Concurrently, using immunofluorescence (IF) and Western blot (WB) techniques, we evaluated the expression and distribution of tight junction proteins, including ZO-1, occludin, and claudin-5.

Results

Our data showed that TS and EC negatively affect sucrose and mannitol permeability starting after 6 h and up to 24 h. The loss of barrier integrity was associated with a reduction of TEER values. While the overall expression level of ZO-1 and occludin was not significantly downregulated, the distribution of ZO-1 was altered, and discontinuation patterns were evident through IF imaging. In contrast to occludin, claudin-5 expression was significantly decreased by TS and EC, as demonstrated by WB and IF data.

Conclusion

In agreement with previous studies, our data showed the metformin could counteract the negative impact of TS and EC on BBB integrity, thus suggesting the possibility of repurposing this drug to afford cerebrovascular protection.

The Relationship Between Smoking and Delayed Cerebral Ischemia After Intracranial Aneurysm Rupture: A Systematic Review and Meta-Analysis

Background: Delayed cerebral ischemia (DCI) is the main cause of death and disability after intracranial aneurysm rupture. Previous studies have shown that smoking can lead to DCI after intracranial aneurysm rupture. However, some recent studies have shown that nicotine, as the main ingredient of tobacco, can cause cerebral vasodilation. This view has led to a debate about the relationship between smoking and DCI. This study aims to determine the relationship between smoking and DCI.

Methods: A systematic literature search was performed according to PRISMA guidelines. The Cochrane Library, Web of Science, PubMed, and Embase online databases were searched for studies published up to September 2020. All studies related to smoking and DCI were included in the analysis. The R and RevMan software were used for data analysis, and random or fixed model analysis was selected depending on the degree of heterogeneity. Publication bias was examined by using the Begg–Mazumdar test and using contour-enhanced funnel plots with trim method.

Results: A total of eight original articles (12 cohorts) with 10,722 patients were included in this meta-analysis. There were statistically significant higher rates of DCI in the smoking group than in the non-smoking group (RR_total = 1.16, 95%CI: 1.05–1.27). After heterogeneity among cohorts was removed by sensitivity analysis, there was still a statistically significant difference in the incidence of DCI between the smoking and non-smoking groups (RR_total = 1.13, 95%CI: 1.07–1.20).

Conclusions: Although the effects of nicotine as the main component of tobacco are unclear in terms of cerebral vessels, the present study suggests that smoking is a risk factor for DCI in patients with ruptured aneurysm.

Tobacco Use: A Major Risk Factor of Intracerebral Hemorrhage

Spontaneous intracerebral hemorrhage (sICH) is one of the deadliest subtypes of stroke, and no treatment is currently available. One of the major risk factors is tobacco use. In this article, we review literature on how tobacco use affects the risk of sICH and also summarize the known effects of tobacco use on outcomes following sICH. Several studies demonstrate that the risk of sICH is higher in current cigarette smokers compared to non-smokers. The literature also establishes that cigarette smoking not only increases the risk of sICH but also increases hematoma growth, results in worse outcomes, and increases the risk of death from sICH. This review also discusses potential mechanisms activated by tobacco use which result in an increase in risk and severity of sICH. Exploring the underlying mechanisms may help alleviate the risk of sICH in tobacco users as well as may help better manage tobacco user sICH patients.

Cerebrovascular and Neurological Dysfunction under the Threat of COVID-19: Is There a Comorbid Role for Smoking and Vaping?

The recently discovered novel coronavirus, SARS-CoV-2 (COVID-19 virus), has brought the whole world to standstill with critical challenges, affecting both health and economic sectors worldwide. Although initially, this pandemic was associated with causing severe pulmonary and respiratory disorders, recent case studies reported the association of cerebrovascular-neurological dysfunction in COVID-19 patients, which is also life-threatening. Several SARS-CoV-2 positive case studies have been reported where there are mild or no symptoms of this virus. However, a selection of patients are suffering from large artery ischemic strokes. Although the pathophysiology of the SARS-CoV-2 virus affecting the cerebrovascular system has not been elucidated yet, researchers have identified several pathogenic mechanisms, including a role for the ACE2 receptor. Therefore, it is extremely crucial to identify the risk factors related to the progression and adverse outcome of cerebrovascular-neurological dysfunction in COVID-19 patients. Since many articles have reported the effect of smoking (tobacco and cannabis) and vaping in cerebrovascular and neurological systems, and considering that smokers are more prone to viral and bacterial infection compared to non-smokers, it is high time to explore the probable correlation of smoking in COVID-19 patients. Herein, we have reviewed the possible role of smoking and vaping on cerebrovascular and neurological dysfunction in COVID-19 patients, along with potential pathogenic mechanisms associated with it.

Risk factors for ischemic stroke in patients with non-valvular atrial fibrillation and therapeutic international normalized ratio range

INTRODUCTION

Atrial fibrillation (AF) is the most common cause of ischemic stroke (IS). Atrial fibrillation patients are recommended to use oral anticoagulants (OACs) as part of prevention against IS. However, despite having a therapeutic intensity of OAC therapy, IS can still occur in such patients. The aim of our study was to examine the configuration of IS risk factors in patients with non-valvular atrial fibrillation (NVAF) and within the therapeutic INR range (TINR).

MATERIAL AND METHODS

Our retrospective study involved 1835 patients with a recent IS. The experimental group consisted of 154 patients with acute IS, NVAF and TINR. The control group consisted of 1681 patients with acute IS but without AF.

RESULTS

Patients with IS, NVAF and TINR were significantly older and more often female than patients with IS without NVAF (p < 0.001 and p < 0.001, respectively). In these patients, diabetes mellitus, dyslipidemia, hypertension, coronary heart disease, smoking and previous IS were significantly more frequent than in the patients with IS without NVAF (p = 0.036, p = 0.002, p < 0.001, p < 0.001, p < 0.001, p = 0.003). Based on a univariable and multivariable logistic regression model, we found that in the group of patients who suffered a stroke despite TINR compared to patients with IS without AF there were more smokers (OR = 20.337; OR = 147.589) and patients with previous stroke (OR = 6.556; OR = 11.094), hypertension (OR = 3.75; OR = 2.75) and dyslipidemia (OR = 2.318; OR = 2.294).

CONCLUSIONS

The group of patients with NVAF and TINR is significantly more burdened by other independent common risk factors for stroke.

Polyphenols and Oxidative Stress in Atherosclerosis-Related Ischemic Heart Disease and Stroke

Good nutrition could maintain health and life. Polyphenols are common nutrient mainly derived from fruits, vegetables, tea, coffee, cocoa, mushrooms, beverages, and traditional medicinal herbs. They are potential substances against oxidative-related diseases, for example, cardiovascular disease, specifically, atherosclerosis-related ischemic heart disease and stroke, which are health and economic problems recognized worldwide. In this study, we reviewed the risk factors for atherosclerosis, including hypertension, diabetes mellitus, hyperlipidemia, obesity, and cigarette smoking as well as the antioxidative activity of polyphenols, which could prevent the pathology of atherosclerosis, including endothelial dysfunction, low-density lipoprotein oxidation, vascular smooth muscle cell proliferation, inflammatory process by monocytes, macrophages or T lymphocytes, and platelet aggregation. The strong radical-scavenging properties of polyphenols would exhibit antioxidative and anti-inflammation effects. Polyphenols reduce ROS production by inhibiting oxidases, reducing the production of superoxide, inhibiting OxLDL formation, suppressing VSMC proliferation and migration, reducing platelet aggregation, and improving mitochondrial oxidative stress. Polyphenol consumption also inhibits the development of hypertension, diabetes mellitus, hyperlipidemia, and obesity. Despite the numerous in vivo and in vitro studies, more advanced clinical trials are necessary to confirm the efficacy of polyphenols in the treatment of atherosclerosis-related vascular diseases.

A convenient UHPLC-MS/MS method for routine monitoring of plasma and brain levels of nicotine and cotinine as a tool to validate newly developed preclinical smoking model in mouse

Background

A sensitive, rapid and selective UHPLC–MS/MS method has been developed and validated for the quantification of Nicotine (NT) and Cotinine (CN) using Continine-d₃ as internal standard (IS) as per FDA guidelines. Sample preparation involved simple protein precipitation of 20 µL mouse plasma or brain homogenate using acetonitrile at 1:8 ratio. Mass Spectrometer was operated in positive polarity under the multiple reaction-monitoring mode using electro spray ionization technique and the transitions of m/z 163.2 → 132.1, 177.2 → 98.0 and 180.2 → 101.2 were used to measure the NT, CN and IS, respectively. The elution of NT, CN and IS are at 1.89, 1.77 and 1.76 min, respectively. This was achieved with a gradient mobile phase consisting of 5 mM ammonium bicarbonate, acetonitrile and methanol (3:1, v/v) at a flow rate of 0.3 mL/min on a Kinetex EVO C18 column. The method was validated with a lower limit of quantitation 3.0 ng/mL in mouse plasma and brain for both the analytes.

Results

A linear response function was established for the range of concentrations 3–200 (r > 0.995) for NT and 3–600 ng/mL (r > 0.995) for CN. The intra- and inter-day precision values met the acceptance criteria. NT and CN are stable in the battery of stability studies viz., stock solution, bench-top and auto-sampler.

Conclusion

This method was successfully utilized to validate a newly developed preclinical smoking model in mice.

Role of Nrf2 and protective effects of Metformin against tobacco smoke-induced cerebrovascular toxicity

Cigarette smoking (CS) is associated with vascular endothelial dysfunction in a causative way primarily related to the TS content of reactive oxygen species (ROS), nicotine, and inflammation. TS promotes glucose intolerance and increases the risk of developing type-2 diabetes mellitus (2DM) with which it shares other pathogenic traits including the high risk of cerebrovascular and neurological disorders like stroke via ROS generation, inflammation, and blood-brain barrier (BBB) impairment. Herein we provide evidence of the role played by nuclear factor erythroid 2-related factor (Nrf2) in CS-induced cerebrobvascular/BBB impairments and how these cerebrovascular harmful effects can be circumvented by the use of metformin (MF; a widely prescribed, firstline anti-diabetic drug) treatment. Our data in fact revealed that MF activates counteractive mechanisms primarily associated with the Nrf2 pathway which drastically reduce CS toxicity at the cerebrovascular level. These include the suppression of tight junction (TJ) protein downregulation and loss of BBB integrity induced by CS, reduction of inflammation and oxidative stress, renormalization of the expression levels of the major BBB glucose transporter Glut-1 and that of the anticoagulant factor thrombomodulin. Further, we provide additional insights on the controversial interplay between Nrf2 and AMPK.

Offsetting the impact of smoking and e-cigarette vaping on the cerebrovascular system and stroke injury: Is Metformin a viable countermeasure?

Recently published in vitro and in vivo findings strongly suggest that BBB impairment and increased risk for stroke by tobacco smoke (TS) closely resemble that of type-2 diabetes (2DM) and develop largely in response to common key modulators such oxidative stress (OS), inflammation and alterations of the endogenous antioxidative response system (ARE) regulated by the nuclear factor erythroid 2-related factor (Nrf2). Preclinical studies have also shown that nicotine (the principal e-liquid's ingredient used in e-cigarettes) can also cause OS, exacerbation of cerebral ischemia and secondary brain injury. Herein we provide evidence that likewise to TS, chronic e-Cigarette (e-Cig) vaping can be prodromal to the loss of blood-brain barrier (BBB) integrity and vascular inflammation as well as act as a promoting factor for the onset of stroke and worsening of post-ischemic brain injury. In addition, recent reports have shown that Metformin (MF) treatment before and after ischemic injury reduces stress and inhibits inflammatory responses. Recent published data by our group revealead that MF promotes the activation of counteractive mechanisms mediated by the activation of Nrf2 which drastically reduce TS toxicity at the brain and cerebrovascular levels and protect BBB integrity. In this study we provide additional in vivo evidence showing that MF can effectively reduce the oxidative and inflammatory risk for stroke and attenuate post-ischemic brain injury promoted by TS and e-Cig vaping. Our data also suggest that MF administration could be extended as prophylactic care during the time window required for the renormalization of the risk levels of stroke following smoking cessation thus further studies in that direction are warrated.

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Chronic cigarette and e-cigarette exposure downregulate throbomodulin and Nrf2.

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Chronic CS and e-Cig exposure worsen stroke outcome in mice undergoing tMCAO.

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Metformin ameliorate stroke outcomes in CS and e-Cig exposed mice undergoing tMCAO.

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MF protective effect correlates with renormalization of Nrf2 levels.

Protecting the BBB endothelium against cigarette smoke-induced oxidative stress using popular antioxidants: Are they really beneficial?

Blood Brain Barrier (BBB) exposed to realistic concentrations (comparable to a chronic heavy smoker) of Cigarette Smoke Extract (CSE) triggers a strong endothelial inflammatory response which can lead to the onset of neurological disorders. The involvement of Reactive Oxygen Species (ROS) in this inflammatory cascade is evident from the up-regulation of nuclear factor erythroid 2 related factor 2 (Nrf-2), a transcription factor involved in anti-oxidant response signaling in CSE exposed endothelial cells. We have shown that pre-treatment with α-tocopherol and/or ascorbic acid is highly protective for the BBB, thus suggesting that, prophylactic administration of antioxidants can reduce CSE and/or inflammatory-dependent BBB damage. We have assessed and ranked the protective effects of 5 popular OTC antioxidants (Coenzyme Q10, melatonin, glutathione, lipoic acid and resveratrol) against CSE-induced BBB endothelial damage using hCMEC/D3 cells. The analysis of pro-inflammatory cytokines release by ELISA revealed that resveratrol, lipoic acid melatonin and Co-Q10 inhibited the BBB endothelial release of pro-inflammatory cytokines IL-6 and IL-8, reduced (not Co-Q10) CSE-induced up-regulation of Platelet Cell Adhesion Molecule-1 (PECAM-1), Vascular Cell Adhesion Molecule-1 (VCAM-1) & E-selectin and inhibited monocytes-endothelial cell adhesion. The anti-inflammatory effects correlated with the anti-oxidative protection endowed by these compounds as evidenced by upregulation of NADPH: Quinone Oxidoreductase 1 (NQO1) and reduced cellular oxidative stress. CSE-induced release of Vascular Endothelial Growth Factor (VEGF) was inhibited by all tested compounds although the effect was not strictly dose-dependent. Further in vivo studies are required to validate our results and expand our current study to include combinatorial treatments.

Bacoside A: Role in Cigarette Smoking Induced Changes in Brain

Cigarette smoking (CS) is a major health hazard that exerts diverse physiologic and biochemical effects mediated by the components present and generated during smoking. Recent experimental studies have shown predisposition to several biological consequences from both active and passive cigarette smoke exposure. In particular, passive smoking is linked to a number of adverse health effects which are equally harmful as active smoking. A pragmatic approach should be considered for designing a pharmacological intervention to combat the adverse effects of passive smoking. This review describes the results from a controlled experimental condition, testing the effect of bacoside A (BA) on the causal role of passive/secondhand smoke exposure that caused pathological and neurological changes in rat brain. Chronic exposure to cigarette smoke induced significant changes in rat brain histologically and at the neurotransmitter level, lipid peroxidation states, mitochondrial functions, membrane alterations, and apoptotic damage in rat brain. Bacoside A is a neuroactive agent isolated from Bacopa monnieri. As a neuroactive agent, BA was effective in combating these changes. Future research should examine the effects of BA at molecular level and assess its functional effects on neurobiological and behavioral processes associated with passive smoke.

Impact of Scotland's comprehensive, smoke-free legislation on stroke

Background

Previous studies have reported a reduction in acute coronary events following smoke-free legislation. Evidence is lacking on whether stroke is also reduced. The aim was to determine whether the incidence of stroke, overall and by sub-type, fell following introduction of smoke-free legislation across Scotland on 26 March 2006.

Methods and Findings

A negative binomial regression model was used to determine whether the introduction of smoke-free legislation resulted in a step and/or slope change in stroke incidence. The model was adjusted for age-group, sex, socioeconomic deprivation quintile, urban/rural residence and month. Interaction tests were also performed. Routine hospital administrative data and death certificates were used to identify all hospital admissions and pre-hospital deaths due to stroke (ICD10 codes I61, I63 and I64) in Scotland between 2000 and 2010 inclusive. Prior to the legislation, rates of all stroke, intracerebral haemorrhage and unspecified stroke were decreasing, whilst cerebral infarction was increasing at 0.97% per annum. Following the legislation, there was a dramatic fall in cerebral infarctions that persisted for around 20 months. No visible effect was observed for other types of stroke. The model confirmed an 8.90% (95% CI 4.85, 12.77, p<0.001) stepwise reduction in cerebral infarction at the time the legislation was implemented, after adjustment for potential confounders.

Conclusions

Following introduction of national, comprehensive smoke-free legislation there was a selective reduction in cerebral infarction that was not apparent in other types of stroke.

In vitro assessment of tobacco smoke toxicity at the BBB: do antioxidant supplements have a protective role?

BACKGROUND

Tobacco smoke (TS) contains highly reactive oxygen species (such as hydrogen peroxide, peroxynitrite, etc), which cause oxidative damage in vascular tissue and may exacerbate inflammatory events leading to the blood-brain barrier damage (BBBD) which accompanies the development of a variety of neurological disorders. Smokers often have elevated leukocyte counts (primarily neutrophils and monocytes), and significant decreases in plasma alpha-tocopherol (vitamin E) and ascorbic acid (vitamin C) levels due to increased anti-oxidative mobilization in response to oxidative stress evoked by TS. For this purpose, using static culture systems and a well-established dynamic in vitro BBB model (DIV-BBB) we tested the hypothesis that antioxidant vitamin supplementation (E and/or C) can protect the BBB during exposure to whole soluble TS.

RESULTS

TS exacerbates inflammatory events and leads to endothelial overexpression of vascular adhesion molecules (VCAM-1, P-selectin and E-selectin), release of pro-inflammatory cytokines (TNF-α and IL-6) and nitric oxide (NO), release and activation of matrix metalloproteinases (MMP-2 and MMP-9), monocytic maturation into macrophages, and adhesion to the vascular endothelium. Furthermore, TS altered the normal glucose metabolic behaviour of in vitro BBB capillaries and caused a period of transient anaerobic respiration to meet the cellular bioenergetic demand. Pre-treatment with antioxidant vitamins (C and/or E) effectively reduced the pro-inflammatory activity associated with TS, protecting the viability and functions of the BBB.

CONCLUSION

Our results have shown that loss of endothelial viability as well as BBB function and integrity caused by TS exposure can be prevented or at least reduced by normal physiologic concentrations of antioxidant vitamins in vitro.

Pathophysiological impact of cigarette smoke exposure on the cerebrovascular system with a focus on the blood-brain barrier: expanding the awareness of smoking toxicity in an underappreciated area

Recent evidence has indicated that active and passive cigarette smoking are associated, in a dose-dependent manner, with dysfunction of normal endothelial physiology. Tobacco smoke (TS) may predispose individuals to atherogenic and thrombotic problems, significantly increasing the risk for ischemic manifestations such as acute coronary syndrome and stroke. Despite the strong evidence for an association between smoking and vascular impairment, the impact of TS exposure on the blood-brain barrier (BBB) has only been marginally addressed. This is a major problem given that the BBB is crucial in the maintenance of brain homeostasis. Recent data have also shown that chronic smokers have a higher incidence of small vessel ischemic disease (SVID), a pathological condition characterized by leaky brain microvessels and loss of BBB integrity. In the brain TS increases the risk of silent cerebral infarction (SCI) and stroke owing to the pro-coagulant and atherogenic effects of smoking. In this article we provide a detailed review and analysis of current knowledge of the pathophysiology of tobacco smoke toxicity at the cerebrovascular levels. We also discuss the potential toxicity of recently marketed “potential-reduced exposure products”.

Tobacco smoke: a critical etiological factor for vascular impairment at the blood-brain barrier

Active and passive tobacco smoke are associated with the dysfunction of endothelial physiology and vascular impairment. Studies correlating the effects of smoking and the brain microvasculature at the blood-brain barrier (BBB) level have been largely limited to few selective compounds that are present in the tobacco smoke (TS) yet the pathophysiology of smoking has not been unveiled. For this purpose, we characterized the physiological response of isolated human brain microvascular endothelial cells (HBMEC) and monocytes to the exposure of whole soluble TS extract. With the use of a well established humanized flow-based in vitro blood-brain barrier model (DIV-BBB) we have also investigated the BBB physiological response to TS under both normal and impaired hemodynamic conditions simulating ischemia. Our results showed that TS selectively decreased endothelial viability only at very high concentrations while not significantly affecting that of astrocytes and monocytes. At lower concentrations, despite the absence of cytotoxicity, TS induced a strong vascular pro-inflammatory response. This included the upregulation of endothelial pro-inflammatory genes, a significant increase of the levels of pro-inflammatory cytokines, activated matrix metalloproteinase, and the differentiation of monocytes into macrophages. When flow-cessation/reperfusion was paired with TS exposure, the inflammatory response and the loss of BBB viability were significantly increased in comparison to sham-smoke condition. In conclusion, TS is a strong vascular inflammatory primer that can facilitate the loss of BBB function and viability in pathological settings involving a local transient loss of cerebral blood flow such as during ischemic insults.

Risk factors for primary intracerebral hemorrhage in patients in Izumo City, Japan

The annual incidence rate of primary intracerebral hemorrhage (ICH) in Izumo City, Japan, appears to be the highest rate among those reported. Despite improvement of management and surgical therapy, the overall morbidity and mortality after ICH are still high. The author investigated the risk factors for ICH in patients in Izumo. A case-control study of 242 patients (137 men and 105 women with ages ranging from 34 to 97 years) with primary ICH was conducted in Izumo between 1991 and 1998. Hypertension, diabetes mellitus, heart disease, liver disease, alcohol consumption, cigarette smoking, and serum levels of total cholesterol, aspartate aminotransferase, and alanine aminotransferase were assessed as possible risk factors for ICH by using conditional logistic regression. The prevalence of hypertension among ICH patients was 77% and the odds ratio (OR) for hypertension was 17.07 (95% CI: 8.30-35.09), which are much higher than figures reported from Western countries. The OR for hypertension was higher in individuals < or = 69 years of age than in those > or = 70 years of age and lower for lobar hemorrhage than for hemorrhages at other sites. High serum total cholesterol (> or = 220 mg/dl) was the second most important risk factor for ICH (OR: 2.52; 95% CI: 1.23-5.14), and low total cholesterol (< 160 mg/dl) decreased the risk of ICH (OR: 0.47; 95% CI: 0.27-0.82). In contrast, heart disease decreased the risk of ICH, and there was no observed association between alcohol consumption, cigarette smoking, or diabetes mellitus and ICH. This study conducted in Izumo suggests that hypertension is the most important risk factor for ICH and contrary to most previous studies indicates that serum total cholesterol concentration is also positively associated with the risk of ICH. In contrast, heart disease may decrease the risk of ICH.

Smoking and non-smoking tobacco as risk factors in subarachnoid haemorrhage

OBJECTIVE

Swedish snuff is a particular form of non-smoking tobacco with high nicotine content. It is unknown whether this form of tobacco is a risk factor similar to smoking for suffering subarachnoid haemorrhage (SAH). In the present study we report our finding concerning smoking and snuff as risk factors for the disease.

METHOD

We analysed 120 consecutive patients with SAH regarding consumption of tobacco, in order to evaluate if snuff also is associated with an increased risk of SAH.

RESULTS

The relative risk of SAH was about 2.5 times higher for smokers compared with the background population. Consumption of snuff was not associated with an increased risk.

CONCLUSIONS

It seems unlikely that nicotine is solely responsible for the rupture of cerebral aneurysms. The final cause of the increased risk for suffering SAH has to be sought in other factors associated with tobacco smoking.

Protein kinase C family members as a target for regulation of blood-brain barrier Na,K,2Cl-cotransporter during in vitro stroke conditions and nicotine exposure

PURPOSE

The aim of the study is to identify specific protein kinase C (PKC) isoforms involvement in K(+) transport mediated at altered blood-brain barrier (BBB) response to stroke conditions with prior nicotine exposure, which provides ways to intervene pharmacologically in PKC-mediated molecular pathways that could lead to effective treatment for smoking stroke patients.

METHODS

Changes in PKC isoform levels were studied in the cytosolic and membrane fractions of bovine brain microvessel endothelial cells subjected to stroke conditions as well as nicotine/cotinine exposure. Furthermore, abluminal Na,K,2Cl-cotransporter (NKCC) activity regulated by specific conventional PKC isoform activators and inhibitors was investigated using rubidium ((86)Rb) uptake studies.

RESULTS

Membrane-bound PKCalpha, PKCbetaI, and PKCepsilon levels were increased after 6 h hypoxia/aglycemia, and this was attenuated by 24-h nicotine/cotinine exposure. Interestingly, membrane-bound PKCgamma protein level was decreased after 6 h hypoxia/aglycemia and increased by 24-h nicotine/cotinine exposure. (86)Rb uptake studies showed that basolateral NKCC activity was down-regulated by both a conventional PKC inhibitor and specific inhibitors for PKCalpha, PKCbeta, and PKCvarepsilon and was up-regulated by an activator of conventional PKCs during 6-h hypoxia/aglycemia treatment.

CONCLUSION

Specific PKC inhibitors or activators might be designed to individualize stroke therapies and improve health outcome for smokers by rebalancing ion transport into and out of the brain.

Hypertension and stroke in centenarians, Okinawa, Japan

OBJECTIVE

To investigate the relationship between a history of hypertension, cigarette smoking and alcohol intake and the lifetime prevalence of stroke in the oldest-old population.

DESIGN

A cross-sectional study.

SUBJECTS

All of the Japanese centenarians in the Okinawa Prefecture (266 men and 1,378 women).

METHODS

Okinawa Prefectural Government conducted health surveys among all of the centenarians in Okinawa. The variables used for analysis were sex, history of stroke, age at the first diagnosis of stroke, history of hypertension, cigarette smoking and alcohol intake. We used multiple logistic regression analysis taking the history of stroke as the dependent variable.

RESULTS

The lifetime prevalence value for stroke was 11.0% in Japanese centenarians. Hypertension was independently associated with an increased lifetime prevalence of stroke (adjusted odds ratio = 2.97 and 95% confidence interval: 2.16-4.08). There was no material relationship between sex, cigarette smoking, oralcohol intake and the prevalence of stroke. When the lifetime prevalence of stroke was divided according to whether stroke had been diagnosed for the first time at the age of 90 years or less or over the age of 90, a significant positive association between hypertension and stroke was more pronounced in centenarians with a diagnosis of stroke at the age of 90 years or less than in those over the age of 90.

CONCLUSIONS

The findings suggest that hypertension may increase the likelihood of stroke in Japanese centenarians in Okinawa although the association between hypertension and stroke was more pronounced in those having stroke at 90 years or younger.

Smoking as a crucial independent determinant of stroke

Background

Although smoking is known to be powerful risk factor for other vascular diseases, such as cardiac and peripheral vascular disease, only relatively recently has evidence for the role of smoking in the development of stroke been established. The reasons for this advance lie in the acknowledgement that stroke is a heterogeneous disease, in which its subtypes are associated with different risk factors. Furthermore, improvements in the stringency of epidemiological studies and the greater use of CT scanning have enabled the role of smoking in the development of stroke to be elucidated.

Summary of review

This is a qualitative examination of high quality epidemiological studies in which the role of smoking and passive smoking, as a risk factor for cerebral infarction, intracerebral haemorrhage and subarachnoid haemorrhage, is examined. In addition, the pathological mechanisms by which smoking or passive smoking may contribute to the development of stroke are reviewed.

Conclusion

Smoking is a crucial independent determinant of cerebral infarction and subarachnoid haemorrhage, however its role in intracerebral haemorrhage is unclear. Although studies are limited, there is evidence that exposure to passive smoking may also increase the risk of stroke. Smoking appears to be involved in the pathogenesis of stroke via direct injury to the vasculature and also by altering haemodynamic factors within the circulation. Importantly, smoking is modifiable risk factor for stroke. Therefore, the encouragement of smoking cessation may result in a substantial reduction in the incidence of this devastating disease.

Active transport of high-affinity choline and nicotine analogs into the central nervous system by the blood-brain barrier choline transporter

Cigarette smoking is strongly implicated in the development of cardiovascular disorders. Recently identified nicotinium analogs may have therapeutic benefit as smoking cessation therapies but may have restricted entry into the central nervous system by the blood-brain barrier (BBB) due to their physicochemical properties. Using the in situ perfusion technique, lobeline, choline, and nicotinium analogs were evaluated for binding to the BBB choline transporter. Calculated apparent K(i) values for the choline transporter were 1.7 microM N-n-octyl choline, 2.2 microM N-n-hexyl choline, 27 microM N-n-decylnicotinium iodide, 31.9 microM N-n-octylpyridinium iodide, 49 microM N-n-octylnicotinium iodide (NONI), 393 microM lobeline, and >/=1000 microM N-methylnicotinium iodide. Nicotine and N-methylpyridinium iodide, however, do not apparently interact with the BBB choline transporter. Given NONI's apparent K(i) value determined in this study and its ability to inhibit nicotine-evoked dopamine release from superfused rat brain slices, potential brain entry of NONI via the BBB choline transporter was evaluated. [(3)H]NONI exhibited a BBB transfer coefficient value of approximately 1.6 x 10(-3) ml/s/g and a K(m) of approximately 250 microM. Unlabeled choline addition to the perfusion fluid reduced [(3)H]NONI brain uptake. We hypothesize the N-n-octyl group on the pyridinium nitrogen of NONI facilitates brain entry via the BBB choline transporter. Thus, NONI may have utility as a smoking cessation agent, given its ability to inhibit nAChRs mediating nicotine-evoked dopamine release centrally, and to be distributed to brain via the BBB choline transporter.

The Prevalence of Cigarette Smoking in an Acute Inpatient Physical Medicine and Rehabilitation Population

The purpose of this study was to determine the prevalence of cigarette smoking among patients before and after discharge from an acute inpatient physical medicine and rehabilitation unit and to assess smokers' interest in and desire for smoking cessation. A consecutive sample of inpatients (n = 233) admitted over a 5-month period to a regional rehabilitation inpatient center for acute rehabilitation treatment was surveyed for their smoking patterns. Ten percent of patients admitted to rehabilitation were active smokers prior to their hospitalization. In spite of reporting high motivation to stop smoking, half were not interested in participating in a smoking cessation program if one were offered to them. Following discharge from inpatient rehabilitation, 54% of a small sample of patients who could be contacted had resumed smoking (all within 4 weeks of being home). Given the prevalence of smoking in this population and its adverse consequences on health and quality of life, we suggest that rehabilitation professionals actively address this health problem during the patient's hospitalization.

Promoting smoking cessation in the rehabilitation setting

Cigarette smoking is a known risk factor in patients with ischemic and hemorrhagic stroke. Smoking also increases the risk of cardiovascular disease, chronic bronchitis, emphysema, peptic ulcers, and cancer of several organs among middle-aged individuals and the elderly. In the elderly, smoking has also been associated with a general decline in physical functioning as a result of the increased incidence of chronic illnesses. The prevalence of smoking among community-dwelling adults aged 65 to 74 yr has been estimated to be 18% for men and 15% for women. More than 30% of Americans who are hospitalized each year are smokers. Although there are no published studies that have established the prevalence of smoking in a rehabilitation population, these data and our own clinical experience suggest that smoking continues to be a significant health problem for many persons who enter the inpatient rehabilitation setting. Because most hospitals have adopted a smoke-free policy, hospitalization itself may initiate a period of nonsmoking in patients who were smokers at the time of their admission. In addition, some smokers choose to quit smoking after stroke or other medical crisis caused by the health risks associated with cigarette smoking. However, research has also revealed a rather low-smoking cessation rate (30%) among smokers who have had a transient ischemic attack despite the health benefits associated with smoking cessation. Given the significant health risks associated with cigarette smoking, particularly in the elderly and those with cerebrovascular compromise, the effects of smoking on the patient's health should be discussed with the patient during inpatient rehabilitation. Unfortunately, given the current healthcare demands of reducing lengths of hospitalization and the focus on functional outcomes, health promotion issues, such as smoking cessation, nutrition, exercise, may not receive the attention that they deserve. Despite these constraints, we believe that the inpatient rehabilitation setting provides an opportunity for a "teachable moment" to introduce the idea of smoking cessation to the active smoker or to encourage continued smoking cessation and relapse prevention to those patients who have not smoked since their admission to the acute care hospital. If instituted in an effective manner, we believe that there could be significant healthcare benefits in establishing a formal smoking cessation or relapse prevention program in the rehabilitation setting.

Migraine and risk of ischaemic stroke: a case-control study

OBJECTIVES

To determine whether migraine is a risk factor for ischaemic stroke.

DESIGN

A case-control study.

SETTING

Two hospitals in Paris.

SUBJECTS

212 patients with stroke (137 men and 75 women) and 212 controls matched for sex, age (to within five years), and history of hypertension.

MAIN OUTCOME MEASURES

Ischaemic stroke, confirmed by brain computed tomography or magnetic resonance imaging, and history of headache, recorded with structured questionnaire during interview.

RESULTS

Prevalence of migraine did not differ between patients with stroke and controls: 18/137 v 17/137 for men (odds ratio 1.1 (95% confidence interval 0.5 to 2.2), p = 0.86); 23/75 v 17/75 for women (odds ratio 1.6 (0.7 to 3.5), p = 0.24); and 41/212 v 34/212 for both sexes (odds ratio 1.3 (0.8 to 2.3), p = 0.33). When subjects were split into two age groups, however, prevalence of migraine was significantly higher among younger women (aged < 45) with stroke compared with their controls (13/20 v 6/20, odds ratio 4.3 (1.2 to 16.3), p = 0.03). Furthermore, the risk of ischaemic stroke was higher among younger women who smoked (7/20 v 1/20, odds ratio 10.2 (1.1 to 93.3)).

CONCLUSIONS

Prevalence of migraine was not different between patients with stroke and matched controls except among women aged < 45, when migraine and stroke were significantly associated.

The acute effect of smoking on platelet and endothelial release reaction is suppressed in chronic smokers

Whilst increased plasma beta-thromboglobulin (beta TG), platelet factor 4 and thrombospondin levels are regarded as reflecting the release reaction of platelets, tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) levels represent endothelial release reaction and/or damage. In this study including 12 smokers and 9 nonsmokers, we investigated the acute and chronic effect of smoking on these parameters and antithrombin III, protein S and fibrinogen, as well. Nonsmokers were found to have somewhat higher plasma levels of beta TG, t-PA and PAI-1 than chronic smokers, and 30 minutes after smoking two cigarettes, these levels and protein S levels of nonsmokers showed more prominent increases than of chronic smokers. It is speculated that chronic exposure to cigarette smoke may cause "exhaustion" or "receptor down-regulation" of platelets and endothelial cells, resulting with diminished release reaction of platelets and endothelium in response to acute smoking.