Activation of the Coagulant Pathway in Cigarette Smokers

Diet, Lifestyle, Smoking

Cardiovascular disease is the leading cause of death globally The past few decades have shown that especially low- and middle-income countries have undergone rapid industrialization, urbanization, economic development and market globalization. Although these developments led to many positive changes in health outcomes and increased life expectancies, they all also caused inappropriate dietary patterns, physical inactivity and obesity. Evidence shows that a large proportion of the cardiovascular disease burden can be explained by behavioural factors such as low physical activity, unhealthy diet and smoking. Controlling these risk factors from early ages is important for maintaining cardiovascular health. Even in patients with genetic susceptibility to cardiovascular disease, risk factor modification is beneficial.Despite the tremendous advances in the medical treatment of cardiovascular risk factors to reduce overall cardiovascular risk, the modern lifestyle which has led to greater sedentary time, lower participation in active transport and time spent in leisure or purposeful physical activity, unhealthy diets and increased exposure to stress, noise and pollution have diminished the beneficial effects of contemporary medical cardiovascular prevention strategies. Therefore attenuating or eliminating these health risk behaviours and risk factors is imperative in the prevention of cardiovascular diseases.

Incidence and Outcomes of Pulmonary Embolism among Hospitalized COVID-19 Patients

OBJECTIVES

Patients with COVID-19 may be at high risk for thrombotic complications due to excess inflammatory response and stasis of blood flow. This study aims to assess the incidence of pulmonary embolism among hospitalized patients with COVID-19, risk factors, and the impact on survival.

METHODS

A retrospective case-control study was conducted at Al-Noor Specialist Hospital in Saudi Arabia between 15 March 2020 and 15 June 2020. Patients with confirmed COVID-19 diagnosis by a real-time polymerase chain reaction (PCR) and confirmed diagnosis of pulmonary embolism by Computed Tomography pulmonary angiogram (CTPA) formed the case group. Patients with confirmed COVID-19 diagnosis by a real-time polymerase chain reaction (PCR) and without confirmed diagnose of pulmonary embolism formed the control group. Logistic regression analysis was used to identify predictors of pulmonary embolism and survival.

RESULTS

A total of 159 patients participated were included in the study, of which 51 were the cases (patients with pulmonary embolism) and 108 patients formed the control group (patients without pulmonary embolism). The incidence of PE among those hospitalized was around 32%. Smoking history, low level of oxygen saturation, and higher D-dimer values were important risk factors that were associated with a higher risk of developing PE (p < 0.05). Higher respiratory rate was associated with higher odds of death, and decreased the possibility of survival among hospitalized patients with PE.

CONCLUSIONS

Pulmonary embolism is common among hospitalized patients with COVID-19. Preventive measures should be considered for hospitalized patients with smoking history, low level of oxygen saturation, high D-dimer values, and high respiratory rate.

The incidence and risk factors of deep venous thrombosis in lower extremities following surgically treated femoral shaft fracture: a retrospective case-control study

Background

There is still a lack of data on deep vein thrombosis (DVT) following surgically treated femoral shaft fracture (FSF). The goal of this study was to investigate the characteristics of postoperative DVT and the association between the occurrence of DVT and risk factors in patients undergoing surgical treatment for FSF.

Methods

This observational retrospective case-control study reviewed 308 patients who received surgical treatment of FSF between January 2016 and October 2020 at a university hospital. Univariate analyses were performed on the data of demographics, comorbidities, laboratory biomarkers, and operation-related indexes. The receiver operating characteristic (ROC) curve analysis, univariate analyses, and multivariate logistic regression analysis were employed to identify the independent risk factors associated with DVT.

Results

In total, 308 patients with surgically treated FSF were included, among whom 48 (15.6%) patients had postoperative DVTs. The univariate analyses showing significant differences regarding DVT were American Society of Anesthesiologists (ASA) classification, diabetes mellitus, current smoking, aspartate transaminase (AST), and very-low-density lipoprotein (VLDL) level among the 34 factors. According to the ROC results, the optimal cutoff values for intraoperative blood loss, d-dimer, and age were 350 ml, 1.08 μg/ml, and 35 years, respectively. The multivariable model demonstrated 4 significantly independent associations with postoperative DVT, including current smoking, intraoperative blood loss (> 550 ml), age (> 35 years), and d-dimer > 1.09 μg/ml.

Conclusion

These risk factors as screening tools contribute to risk stratification of the occurrence of thromboembolic events. In addition, our findings would help orthopedic surgeons make a cross-specialty decision and implement targeted precaution measures for patients with FSF.

Biomarkers of coagulation and fibrinolysis in acute myocardial infarction: a joint position paper of the Association for Acute CardioVascular Care and the European Society of Cardiology Working Group on Thrombosis

The formation of a thrombus in an epicardial artery may result in an acute myocardial infarction (AMI). Despite major advances in acute treatment using network approaches to allocate patients to timely reperfusion and optimal antithrombotic treatment, patients remain at high risk for thrombotic complications. Ongoing activation of the coagulation system as well as thrombin-mediated platelet activation may both play a crucial role in this context. Whether measurement of circulating biomarkers of coagulation and fibrinolysis could be useful for risk stratification in secondary prevention is currently not fully understood. In addition, measurement of such biomarkers could be helpful to identify thrombus formation as the leading mechanism for AMI. The introduction of biomarkers of myocardial injury such as high-sensitivity cardiac troponins made rule-out of AMI even more precise. However, elevated markers of myocardial injury cannot provide proof of a type 1 AMI, let alone thrombus formation. The combined measurement of markers of myocardial injury with biomarkers reflecting ongoing thrombus formation might be helpful for the fast and correct diagnosis of an atherothrombotic type 1 AMI. This position paper gives an overview of the current knowledge and possible role of biomarkers of coagulation and fibrinolysis for the diagnosis of AMI, risk stratification, and individualized treatment strategies in patients with AMI.

Selected Aspects of Tobacco-Induced Prothrombotic State, Inflammation and Oxidative Stress: Modeled and Analyzed Using Petri Nets

Many factors, such as endothelial dysfunction, inflammation and hemostatic disturbances, affect formation and progression of atherosclerotic plaque. In our study, we have focused on hemostatic disturbances with particular emphasis on the extrinsic pathways of coagulation. Thrombin is a main enzyme of coagulation and it is engaged in many different subprocesses. It leads to activation of factors of the coagulation cascade, transition of fibrinogen to fibrin monomer, endothelial damage, inflammation, activation of platelets and proliferation. In our study, selected aspects of disorders in prothrombotic states influenced by cigarette smoke have been modeled and analyzed. Tobacco-induced increased tissue factor, which is associated with less plasminogen activator and increased plasminogen activator-1 inhibitor, has been included in the presented model. These disorders together with accompanying inflammatory state are closely related to thrombus formation and cardiovascular disease promotion. The proposed model has been built using Petri nets and the analysis has been based mainly on t-invariants. Using the Petri net theory to model and analyze the investigated phenomena allows to better understand them by revealing some interesting dependencies in the studied biological system. It explains how tobacco smoke affects the analyzed processes and how harmful these effects are.

Waterpipe Smoking Is Associated with Changes in Fibrinogen, FVII, and FVIII Levels

Cigarette smoking has been shown to be associated with changes in coagulation factors in the circulation and the subsequent thrombosis development. In this study, the impact of waterpipe smoking on the levels of fibrinogen, factor VII (FVII), and factor VIII (FVIII) was investigated. In addition, the effects of waterpipe smoking were compared to those of cigarette smoking and never smokers. A total of 80 male smokers (40 cigarette smokers and 40 waterpipe smokers) and 40 apparently healthy never smokers were recruited in the study. Both waterpipe smoking and cigarette smoking induced significant increases in the plasma levels of fibrinogen, factor VII, and factor VIII (p < 0.01). The magnitude of the increase in fibrinogen levels induced by waterpipe smoking was higher than that induced by cigarette smoking (p < 0.01), while similar increases were observed in other factors (p > 0.05). In addition, in the waterpipe group, the magnitude of the increase in fibrinogen and factor VIII was higher in the smokers with more than 3 years of use (p < 0.05). In conclusion, similar to cigarette smoking, waterpipe smoking modulates the levels of coagulation factors, suggesting its thrombotic potential.

The MAP kinase JNK2 mediates cigarette smoke-induced arterial thrombosis

Despite public awareness of its deleterious effects, smoking remains a major cause of death. Indeed, it is a risk factor for atherothrombotic complications and in line with this, the introduction of smoking ban in public areas reduced smoking-associated cardiovascular complications. Nonetheless, smoking remains a major concern, and molecular mechanisms by which it causes cardiovascular disease are not known. Peripheral blood monocytes from healthy smokers displayed increased JNK2 and tissue factor (TF) gene expression compared to non-smokers (n=15, p<0.05). Similarly, human aortic endothelial cells exposed to cigarette smoke total particulate matter (CS-TPM) revealed increased TF expression mediated by JNK2 (n=4; p<0.05). Wild-type and JNK2^-/- mice were exposed to cigarette smoke for two weeks after which arterial thrombosis was investigated. Wild-type mice exposed to smoke displayed reduced time to thrombotic arterial occlusion (n=8; p<0.05) and increased tissue factor activity (n=7; p<0.05) as compared to wild-type controls (n=6), while JNK2^-/-mice exposed to smoke maintained an unaltered thrombotic potential (n=8; p=NS) and tissue factor activity (n=8) comparable to that of JNK2^-/- and wild-type controls (n=6; p=NS). Smoking caused an increased production of reactive oxygen species (ROS) in wild-type but not in JNK2^-/- mice (n=7; p<0.05 for wild-type mice and n=5-6; p=NS for JNK2^-/- mice). In conclusion, the MAP kinase JNK2 mediates cigarette smoke-induced TF activation, arterial thrombosis and ROS production. These results underscore a major role of JNK2 in smoke-mediated thrombus formation and may offer an attractive target to prevent smoke-related thrombosis in those subjects which do not manage quitting.

Venous thromboembolism has the same risk factors as atherosclerosis: A PRISMA-compliant systemic review and meta-analysis

BACKGROUND

Previous studies have shown that idiopathic pulmonary embolism is positively associated with other cardiovascular events, such as myocardial infarction and stroke, suggesting a potentially important association between atherosclerosis risk factors and venous thromboembolism (VTE). We performed a meta-analysis to evaluate the correlation between risk factors for atherosclerosis and VTE.

METHODS

In December 2014, we searched MEDLINE and EMBASE for studies evaluating the associations between VTE and risk factors for atherosclerosis and pooled outcome data using random-effects meta-analysis. In addition, we analyzed publication bias.

RESULTS

Thirty-three case-control and cohort studies with a total of 185,124 patients met the inclusion criteria. We found that participants with body mass index (BMI) ≥30 kg/m had a significantly higher prevalence of VTE than those with BMI <30 kg/m in both case-control studies (odds ratio [OR] = 2.45, 95% confidence interval [CI]: 1.78-3.35) and cohort studies (relative risk [RR] = 2.39, 95% CI: 1.79-3.17). VTE was more prevalent in patients with hypertension than without hypertension (OR = 1.40, 95% CI: 1.06-1.84; RR = 1.36, 95% CI: 1.11-1.67). The findings were similar for VTE prevalence between patients with and without diabetes (OR = 1.78, 95% CI: 1.17-2.69; RR = 1.41, 95% CI: 1.20-1.66). Current smoking was significantly associated with VTE prevalence in case-control studies (OR = 1.34, 95% CI: 1.01-1.77), but not in cohort studies (RR = 1.29, 95% CI: 0.96-1.72). In addition, we found that total cholesterol and triglyceride concentrations were significantly higher in patients with VTE than without VTE (weighted mean differences [WMD] = 8.94 mg/dL, 95% CI: 3.52-14.35 mg/dL, and WMD = 14.00 mg/dL, 95% CI: 8.85-19.16 mg/dL, respectively). High-density lipoprotein cholesterol concentrations were significantly lower in patients with VTE than without VTE (WMD = -2.03 mg/dL, 95% CI: -3.42 to -0.63 mg/dL). Higher quality studies were more homogeneous, but confirmed the same significant associations.

CONCLUSIONS

Based on our systematic review and meta-analysis, we observed a significant association between VTE and the risk factors for atherosclerosis. These results may make an important contribution to clinical practice regarding VTE treatment.

Pathobiology of tobacco smoking and neurovascular disorders: untied strings and alternative products

Tobacco smoke (TS) is the leading cause of preventable deaths worldwide. In addition to a host of well characterized diseases including chronic obstructive pulmonary disease, oral and peripheral cancers and cardiovascular complications, epidemiological evidence suggests that chronic smokers are at equal risk to develop neurological and neurovascular complications such as multiple sclerosis, Alzheimer's disease, stroke, vascular dementia and small vessel ischemic disease (SVID). Unfortunately, few direct neurotoxicology studies of tobacco smoking and its pathogenic pathways have been produced so far. A major link between TS and CNS disorders is the blood-brain barrier (BBB). In this review article, we summarize the current understanding of the toxicological impact of TS on BBB physiology and function and major compensatory mechanisms such as nrf2- ARE signaling and anti-inflammatory pathways activated by TS. In the same context, we discuss the controversial role of antioxidant supplementation as a prophylactic and/or therapeutic approach in delaying or decreasing the disease complications in smokers. Further, we cover a number of toxicological studies associated with "reduced exposure" cigarette products including electronic cigarettes. Finally, we provide insights on possible avenues for future research including mechanistic studies using direct inhalation rodent models.

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.

Platelet activation as a novel mechanism of atherothrombotic risk in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterized by pulmonary and systemic inflammation. In particular, the clinical course of this disease typically leads to periodic exacerbation involving inflammatory response and both respiratory and cardiovascular symptoms. Even though the exact mechanisms underlying the pathogenesis of COPD and its chronic and acute inflammation have not yet been fully understood, many studies have been highlighting the role of the endothelium, platelets (PTL) and other circulating blood cells. PLT are crucial for hemostasis and, once activated by a number of different factors, will mediate endothelium adhesion, and the rolling and activation of other circulating cells, such as neutrophils, which become a cause of tissue damage during the inflammatory process. The aim of this review is to highlight the onset of activation, thrombus formation and inflammatory amplification with particular regard to the COPD patients and the course of their acute exacerbations.

Oxidative and pro-inflammatory impact of regular and denicotinized cigarettes on blood brain barrier endothelial cells: is smoking reduced or nicotine-free products really safe?

Background

Both active and passive tobacco smoke (TS) potentially impair the vascular endothelial function in a causative and dose-dependent manner, largely related to the content of reactive oxygen species (ROS), nicotine, and pro-inflammatory activity. Together these factors can compromise the restrictive properties of the blood–brain barrier (BBB) and trigger the pathogenesis/progression of several neurological disorders including silent cerebral infarction, stroke, multiple sclerosis and Alzheimer’s disease. Based on these premises, we analyzed and assessed the toxic impact of smoke extract from a range of tobacco products (with varying levels of nicotine) on brain microvascular endothelial cell line (hCMEC/D3), a well characterized human BBB model.

Results

Initial profiling of TS showed a significant release of reactive oxygen (ROS) and reactive nitrogen species (RNS) in full flavor, nicotine-free (NF, “reduced-exposure” brand) and ultralow nicotine products. This release correlated with increased oxidative cell damage. In parallel, membrane expression of endothelial tight junction proteins ZO-1 and occludin were significantly down-regulated suggesting the impairment of barrier function. Expression of VE-cadherin and claudin-5 were also increased by the ultralow or nicotine free tobacco smoke extract. TS extract from these cigarettes also induced an inflammatory response in BBB ECs as demonstrated by increased IL-6 and MMP-2 levels and up-regulation of vascular adhesion molecules, such as VCAM-1 and PECAM-1.

Conclusions

In summary, our results indicate that NF and ultralow nicotine cigarettes are potentially more harmful to the BBB endothelium than regular tobacco products. In addition, this study demonstrates that the TS-induced toxicity at BBB ECs is strongly correlated to the TAR and NO levels in the cigarettes rather than the nicotine content.

The biology behind the atherothrombotic effects of cigarette smoke

Cigarette smoke is an aerosol that contains >4,000 chemicals, including nicotine, carbon monoxide, acrolein, and oxidant compounds. Exposure to cigarette smoke induces multiple pathological effects in the endothelium, several of which are the result of oxidative stress initiated by reactive oxygen species, reactive nitrogen species, and other oxidant constituents of cigarette smoke. Cigarette-smoke exposure interferes adversely with the control of all stages of plaque formation and development and pathological thrombus formation. The reactive oxygen species in cigarette smoke contribute to oxidative stress, upregulation of inflammatory cytokines, and endothelial dysfunction, by reducing the bioavailability of nitric oxide. Plaque formation and the development of vulnerable plaques also result from exposure to cigarette smoke via the enhancement of inflammatory processes and the activation of matrix metalloproteases. Moreover, exposure to cigarette smoke results in platelet activation, stimulation of the coagulation cascade, and impairment of anticoagulative fibrinolysis. Many cigarette-smoke-mediated prothrombotic changes are quickly reversible upon smoking cessation. Public health efforts should urgently promote our understanding of current cigarette-smoke-induced cardiovascular pathology to encourage individuals to reduce their exposure to cigarette smoke and, therefore, the detrimental consequences of associated atherothrombotic disease.

Current and former smoking and risk for venous thromboembolism: a systematic review and meta-analysis

BACKGROUND

Smoking is a well-established risk factor for atherosclerotic disease, but its role as an independent risk factor for venous thromboembolism (VTE) remains controversial. We conducted a meta-analysis to summarize all published prospective studies and case-control studies to update the risk for VTE in smokers and determine whether a dose-response relationship exists.

METHODS AND FINDINGS

We performed a literature search using MEDLINE (source PubMed, January 1, 1966 to June 15, 2013) and EMBASE (January 1, 1980 to June 15, 2013) with no restrictions. Pooled effect estimates were obtained by using random-effects meta-analysis. Thirty-two observational studies involving 3,966,184 participants and 35,151 VTE events were identified. Compared with never smokers, the overall combined relative risks (RRs) for developing VTE were 1.17 (95% CI 1.09-1.25) for ever smokers, 1.23 (95% CI 1.14-1.33) for current smokers, and 1.10 (95% CI 1.03-1.17) for former smokers, respectively. The risk increased by 10.2% (95% CI 8.6%-11.8%) for every additional ten cigarettes per day smoked or by 6.1% (95% CI 3.8%-8.5%) for every additional ten pack-years. Analysis of 13 studies adjusted for body mass index (BMI) yielded a relatively higher RR (1.30; 95% CI 1.24-1.37) for current smokers. The population attributable fractions of VTE were 8.7% (95% CI 4.8%-12.3%) for ever smoking, 5.8% (95% CI 3.6%-8.2%) for current smoking, and 2.7% (95% CI 0.8%-4.5%) for former smoking. Smoking was associated with an absolute risk increase of 24.3 (95% CI 15.4-26.7) cases per 100,000 person-years.

CONCLUSIONS

Cigarette smoking is associated with a slightly increased risk for VTE. BMI appears to be a confounding factor in the risk estimates. The relationship between VTE and smoking has clinical relevance with respect to individual screening, risk factor modification, and the primary and secondary prevention of VTE. Please see later in the article for the Editors' Summary.

Cigarette smoke and inflammation: role in cerebral aneurysm formation and rupture

Smoking is an established risk factor for subarachnoid hemorrhage yet the underlying mechanisms are largely unknown. Recent data has implicated a role of inflammation in the development of cerebral aneurysms. Inflammation accompanying cigarette smoke exposure may thus be a critical pathway underlying the development, progression, and rupture of cerebral aneurysms. Various constituents of the inflammatory response appear to be involved including adhesion molecules, cytokines, reactive oxygen species, leukocytes, matrix metalloproteinases, and vascular smooth muscle cells. Characterization of the molecular basis of the inflammatory response accompanying cigarette smoke exposure will provide a rational approach for future targeted therapy. In this paper, we review the current body of knowledge implicating cigarette smoke-induced inflammation in cerebral aneurysm formation/rupture and attempt to highlight important avenues for future investigation.

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.

Nicotine aggravates the brain postischemic inflammatory response

A substantial body of evidence suggests that nicotine adversely affects cerebral blood flow and the blood-brain barrier and is a risk factor for stroke. The present study investigated the effect of nicotine on cerebrovascular endothelium under basal and ischemia/reperfusion injury under in vivo condition. Nicotine (2 mg/kg sc) was administered to mice over 14 days, which resulted in plasma nicotine levels of ∼100 ng/ml, reflecting plasma concentrations in average to heavy smokers. An analysis of the phenotype of isolated brain microvessels after nicotine exposure indicated higher expression of inflammatory mediators, cytokines (IL-1β, TNF-α, and IL-18), chemokines (CCL2 and CX(3)CL1), and adhesion molecules (ICAM-1, VCAM-1, and P-selectins), and this was accompanied by enhanced leukocyte infiltration into brain during ischemia/reperfusion (P < 0.01). Nicotine had a profound effect on ischemia/reperfusion injury; i.e., increased brain infarct size (P < 0.01), worse neurological deficits, and a higher mortality rate. These experiments illuminate, for the first time, how nicotine regulates brain endothelial cell phenotype and postischemic inflammatory response at the brain-vascular interface.

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”.

Prothrombin fragments in cardiovascular disease

Prothrombin fragment 1+2 (F1+2), which comes from in vivo cleavage of prothrombin by factor Xa, is considered to be useful for diagnosis of thrombosis. Recognition of the central role of thrombosis in the pathogenesis ofcardiovascular disease has prompted growing interest in the association o F1+2 with cardiovascular clinical syndromes. Increased F1+2 levels have reported in venous thromboembolism, inflammation, cancer, sepsis, acute coronary syndromes, stroke, peripheral arterial disease, atrial fibrillation and during the postoperative period. However, a clear relationship with the appearance of thrombosis has not always been consistently demonstrated. Besides its potential prognostic and diagnostic value, it could also be usefu in assessing the impact of various therapies. However, it should be kept in mind that measurement of hemostasis activation markers has several important biological and methodological disadvantages. Activation markers reflect the presence of thrombosis in any vascular bed, so they are not specific. Furthermore, elevations occur not only in the presence of overt thrombosis but also during the hypercoagulable state. The cutoff level to be used for the definition of elevations is still largely unknown due to the use of different analytical methods, none of which have been standardized until know. Finally, the prognostic value of F1+2 and other markers of coagulation activation remains to be fully defined in future studies.

Factors predictive of thrombotic events in LUMINA, a multi-ethnic cohort of SLE patients (LXXII)

OBJECTIVE

Thrombosis is an important cause of morbidity and mortality in SLE. We have explored the factors associated with time to the occurrence of thrombotic events in SLE patients to expand our cohort's previous observations.

METHOD

SLE patients (ACR criteria), age >or=16 years, disease duration

RESULTS

A total of 643 patients were studied; mean (s.d.) age was 36.4 (12.6) years and disease duration at T0 was 1.4 (1.3) years; 90% were female. After T0, 81 (12.6%) patients had developed a thrombotic event. In the MV model, age [hazard ratio (HR) = 1.06; 95% CI 1.03, 1.08; P < 0.0001], health insurance (HR = 0.53; 95% CI 0.30, 0.94; P = 0.029), smoking (HR = 1.85; 95% CI 1.01, 3.40; P = 0.048), damage (T0) (HR = 1.44; 95% CI 1.20, 1.71; P < 0.0001), aPL (HR = 2.12; 95% CI 1.19, 3.76; P = 0.011) and glucocorticoid (highest dose) (HR = 1.01; 95% CI 1.01, 1.02; P < 0.0001) were significant.

CONCLUSIONS

Age, poverty, smoking, damage accrual, aPL and higher doses of glucocorticoids were independently associated with a shorter time to the first thrombotic event; health insurance had a protective effect. Acting upon modifiable risk factors at the personal (smoking, high-dose glucocorticoids) and societal (poverty, health insurance) levels may prevent these events and improve the long-term outcome of SLE patients.

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Key Words

• systemic lupus erythematosus
• thrombotic events
• risk factors

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MESH Headings

• Adult
• Black or African American
• Female
• Hispanic or Latino
• Humans
• Longitudinal Studies
• Lupus Erythematosus, Systemic/complications
• Lupus Erythematosus, Systemic/ethnology
• Lupus Erythematosus, Systemic/mortality
• Male
• Middle Aged
• Proportional Hazards Models
• Risk Factors
• Severity of Illness Index
• Socioeconomic Factors
• Thrombosis/ethnology
• Thrombosis/etiology
• Thrombosis/mortality
• United States
• White People
• Young Adult

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Grants

• P20 RR011126 NCRR NIH HHS
• P01 AR049084 NIAMS NIH HHS
• M01-RR00032 NCRR NIH HHS
• P01 AR49084 NIAMS NIH HHS
• M01-RR02558 NCRR NIH HHS
• M01 RR002558 NCRR NIH HHS
• 1P20RR11126 NCRR NIH HHS
• M01 RR000032 NCRR NIH HHS

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Affiliation(s)

Paula I. Burgos Department of Medicine, Division of Clinical Immunology and Rheumatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA, Department of Clinical Immunology and Rheumatology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile, Department of Surgery, Department of Epidemiology, Schools of Medicine and Public Health, University of Alabama at Birmingham, Birmingham, AL, Department of Medicine, Division of Rheumatology, University of Texas Health Science Center at Houston, Houston, TX, USA and Department of Medicine, Division of Rheumatology, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
Gerald McGwin Department of Medicine, Division of Clinical Immunology and Rheumatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA, Department of Clinical Immunology and Rheumatology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile, Department of Surgery, Department of Epidemiology, Schools of Medicine and Public Health, University of Alabama at Birmingham, Birmingham, AL, Department of Medicine, Division of Rheumatology, University of Texas Health Science Center at Houston, Houston, TX, USA and Department of Medicine, Division of Rheumatology, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
John D. Reveille Department of Medicine, Division of Clinical Immunology and Rheumatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA, Department of Clinical Immunology and Rheumatology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile, Department of Surgery, Department of Epidemiology, Schools of Medicine and Public Health, University of Alabama at Birmingham, Birmingham, AL, Department of Medicine, Division of Rheumatology, University of Texas Health Science Center at Houston, Houston, TX, USA and Department of Medicine, Division of Rheumatology, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
Luis M. Vilá Department of Medicine, Division of Clinical Immunology and Rheumatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA, Department of Clinical Immunology and Rheumatology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile, Department of Surgery, Department of Epidemiology, Schools of Medicine and Public Health, University of Alabama at Birmingham, Birmingham, AL, Department of Medicine, Division of Rheumatology, University of Texas Health Science Center at Houston, Houston, TX, USA and Department of Medicine, Division of Rheumatology, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
Graciela S. Alarcón Department of Medicine, Division of Clinical Immunology and Rheumatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA, Department of Clinical Immunology and Rheumatology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile, Department of Surgery, Department of Epidemiology, Schools of Medicine and Public Health, University of Alabama at Birmingham, Birmingham, AL, Department of Medicine, Division of Rheumatology, University of Texas Health Science Center at Houston, Houston, TX, USA and Department of Medicine, Division of Rheumatology, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico

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Smoking and atherosclerotic cardiovascular disease: part II: role of cigarette smoking in cardiovascular disease development

Potential mechanisms and biomarkers of atherosclerosis related to cigarette smoking - a modifiable risk factor for that disease - are discussed in this article. These include smoking-associated inflammatory markers, such as leukocytes, high-sensitivity C-reactive protein, serum amyloid A, ICAM-1 and IL-6. Other reviewed markers are indicative for smoking-related impairment of arterial endothelial function (transcapillary leakage of albumin, inhibition of endogenous nitric oxide synthase activity and reduced endothelium-dependent vasodilation) or point to oxidative stress caused by various chemicals (cholesterol oxidation, autoantibodies to oxidized low-density lipoprotein, plasma levels of malondialdehyde and F(2)-isoprostanes and reduced antioxidant capacity). Smoking enhances platelet aggregability, increases blood viscosity and shifts the pro- and antithrombotic balance towards increased coagulability (e.g., fibrinogen, von Willebrand factor, ICAM-1 and P-selectin). Insulin resistance is higher in smokers compared with nonsmokers, and hemoglobin A1c is dose-dependently elevated, as is homocysteine. Smoke exposure may influence the kinetics of markers with different response to transient or chronic changes in cigarette smoking behavior.

Adaptive regression modeling of biomarkers of potential harm in a population of U.S. adult cigarette smokers and nonsmokers

BACKGROUND

This article describes the data mining analysis of a clinical exposure study of 3585 adult smokers and 1077 nonsmokers. The analysis focused on developing models for four biomarkers of potential harm (BOPH): white blood cell count (WBC), 24 h urine 8-epi-prostaglandin F2alpha (EPI8), 24 h urine 11-dehydro-thromboxane B2 (DEH11), and high-density lipoprotein cholesterol (HDL).

METHODS

Random Forest was used for initial variable selection and Multivariate Adaptive Regression Spline was used for developing the final statistical models

RESULTS

The analysis resulted in the generation of models that predict each of the BOPH as function of selected variables from the smokers and nonsmokers. The statistically significant variables in the models were: platelet count, hemoglobin, C-reactive protein, triglycerides, race and biomarkers of exposure to cigarette smoke for WBC (R-squared = 0.29); creatinine clearance, liver enzymes, weight, vitamin use and biomarkers of exposure for EPI8 (R-squared = 0.41); creatinine clearance, urine creatinine excretion, liver enzymes, use of Non-steroidal antiinflammatory drugs, vitamins and biomarkers of exposure for DEH11 (R-squared = 0.29); and triglycerides, weight, age, sex, alcohol consumption and biomarkers of exposure for HDL (R-squared = 0.39).

CONCLUSIONS

Levels of WBC, EPI8, DEH11 and HDL were statistically associated with biomarkers of exposure to cigarette smoking and demographics and life style factors. All of the predictors together explain 29%-41% of the variability in the BOPH.

Genetic susceptibility, smoking, obesity and risk of venous thromboembolism

The F5 G1691A (Factor V Leiden) and F2 G20210A (prothrombin) mutations are linked to an increase in the incidence rate of venous thromboembolism (VTE), but their effects are highly variable. We investigated whether the effects of smoking and obesity might explain this variability. In a case-cohort study including the participants of the Danish Diet, Cancer and Health study, we computed incidence rates and Cox proportional hazard ratios for VTE in individuals with and without the mutations, categorized by weight and tobacco consumption. The sole effect of heavy smoking was 128 extra VTE events per 100,000 person years in individuals with the F5 G1691A mutation versus 59 in individuals without. The sole effect of obesity was 222 extra VTE events per 100,000 person years in individuals with the F5 G1691A mutation, versus 103 in individuals without this mutation; and 705 extra VTE events per 100,000 person years in individuals with the F2 G20210A mutation versus 107 in individuals without this mutation. The F5 G1691A and F2 G20210A mutations conferred increased susceptibility to the unfavourable effects of smoking and obesity on the risk for VTE. Thus, individuals with genetic risk factors for VTE might benefit from maintaining a healthy lifestyle.

Smoking and venous thromboembolism: a Danish follow-up study

BACKGROUND

Large-scale prospective studies are needed to assess whether smoking is associated with venous thromboembolism (VTE) (i.e. deep venous thrombosis and pulmonary embolism) independently of established risk factors.

OBJECTIVE

To investigate the association between smoking and the risk of VTE among middle-aged men and women.

METHODS

From 1993 to 1997, 27,178 men and 29,875 women, aged 50-64 years and born in Denmark, were recruited into the Danish prospective study 'Diet, Cancer and Health'. During follow-up, VTE cases were identified in the Danish National Patient Registry. Medical records were reviewed and only verified VTE cases were included in the study. Baseline data on smoking and potential confounders were included in gender stratified Cox proportional hazard models to asses the association between smoking and the risk of VTE. The analyses were adjusted for alcohol intake, body mass index, physical activity, and in women also for use of hormone replacement therapy.

RESULTS

During follow-up, 641 incident cases of VTE were verified. We found a positive association between current smoking and VTE, with a hazard ratio of 1.52 (95% CI, 1.15-2.00) for smoking women and 1.32 (95% CI, 1.00-1.74) for smoking men, and a positive dose-response relationship. Former smokers had the same hazard as never smokers.

CONCLUSIONS

Smoking was an independent risk factor for VTE among middle-aged men and women. Former smokers have the same risk of VTE as never smokers, indicating acute effects of smoking, and underscoring the potential benefits of smoking cessation.

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.

A 12-month, randomized, controlled study to evaluate exposure and cardiovascular risk factors in adult smokers switching from conventional cigarettes to a second-generation electrically heated cigarette smoking system

This randomized, controlled, forced-switching, open-label, parallel-group study in 97 adult male and female smokers of conventional cigarettes evaluated biomarkers of tobacco smoke exposure and cardiovascular risk factors. After baseline measurements, smokers were either switched to a second-generation electrically heated cigarette smoking system (EHCSS) or continued smoking conventional cigarettes for 12 months. Biomarkers of exposure and cardiovascular risk factors were measured at 0.5, 1, 2, 3, 4, 5, 6, 9, and 12 months. There was a rapid and sustained reduction in all biomarkers of exposure after switching to the EHCSS, with statistically significant reductions from baseline in nicotine equivalents (-18%), plasma cotinine (-16%), total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (-73%), total 1-hydroxypyrene (-53%), urine mutagenicity (-52%), 4-aminobiphenyl hemoglobin adducts (-43%), carboxyhemoglobin AUC7-23 h (-80%), and 3-hydroxypropylmercapturic acid (-35%). These reductions in exposure in the EHCSS group were associated with statistically significant and pathophysiologically favorable changes in several cardiovascular risk factors, including white blood cell count (-0.78 x 10(3)/microL), hemoglobin (-0.16 g/dL), hematocrit (-0.44%), urine 11-dehydrothromboxane B2 (-374 ng/24 h), and high-density lipoprotein cholesterol (+5 mg/dL).

Smoking increases the risk of venous thrombosis and acts synergistically with oral contraceptive use

The results of studies investigating the relationship of smoking with venous thrombosis are inconsistent. Therefore, in the MEGA study, a large population-based case-control study, we evaluated smoking as a risk factor for venous thrombosis and the joint effect with oral contraceptive use and the factor V Leiden mutation. Consecutive patients with a first venous thrombosis were included from six anticoagulation clinics. Partners of patients were asked to participate and additional controls were recruited using a random digit dialing method. Participants completed a standardized questionnaire. Individuals with known malignancies were excluded from the analyses, leaving a total of 3,989 patients and 4,900 controls. Current and former smoking resulted in a moderately increased risk of venous thrombosis (odds ratio (OR)(current) 1.43, 95% confidence interval (CI95) 1.28-1.60, OR(former) 1.23, CI95 1.09-1.38) compared with nonsmoking. Adjustment for fibrinogen levels did not substantially change these risk estimates. A high number of pack-years resulted in the highest risk among young current smokers (OR(>or=20 pack-years) 4.30, CI95 2.59-7.14) compared with young nonsmokers. Women who were current smokers and used oral contraceptives had an 8.8-fold higher risk (OR 8.79, CI95 5.73-13.49) than nonsmoking women who did not use oral contraceptives. Relative to nonsmoking noncarriers, the joint effect of factor V Leiden and current smoking led to a 5.0-fold increased risk; for the prothrombin 20210A mutation this was a 6.0-fold increased risk. In conclusion, smoking appears to be a risk factor for venous thrombosis with the greatest relative effect among young women using oral contraceptives.

Acute renal infarction in a heavy smoker

Renal infarction is a rare cause of acute abdominal and flank pain. Whether it occurs due to thrombosis or embolism, the occlusion of the renal arteries always results in renal infarction. Cigarette smoking is a known risk factor for arterial thrombosis. Both vasoconstrictor and pro-thrombotic effects of smoking lead to arterial thrombosis. Herein, we report a case of acute renal infarction in a heavy smoker. The definite diagnosis was made by contrast-enhanced abdominal computerized tomography and renal arteriography.

Influence of physical fitness and smoking on the coagulation system in hypertensive patients: effect on prothrombin fragment F1+2

OBJECT

Recently, prothrombin fragment F1+2 was shown to be a sensitive direct marker of thrombin formation. We examined the effect of lifestyle (including physical activity) on prothrombin fragment F1+2 levels.

METHODS

Using the results of a questionnaire, the subjects were classified into groups on the basis of multiple medications, smoking, exercise, and drinking alcohol. The prothrombin fragment F1+2 levels were compared between each pair of groups and differences were analyzed using the unpaired t-test. Correlations between each parameter and the systolic and diastolic blood pressure, as well as with prothrombin fragment F1+2, were examined by multiple regression analysis. Patients The subjects were 109 patients who had essential hypertension without a past history of thrombotic events

RESULTS

Smokers (1.47 +/- 0.75 vs 0.98 +/- 0.46 nmol/L, p<0.0001), and those without regular exercise (1.22 +/- 0.59 vs 0.68 +/- 0.30 nmol/L, p<0.0001) had higher levels of prothrombin fragment F1+2. Age, lack of exercise, and smoking were significant predictors of a high concentration of prothrombin fragment F1+2. Of the smokers, the patient with a regular exercise had low F1+2 compared with those without regular exercise (0.75 +/- 0.20 vs 2.01 +/- 0.49 nmol/L, p<0.0001.

CONCLUSIONS

In patients with essential hypertension, age, smoking, and lack of regular exercise may increase the risk of thrombosis. Even in smokers, a regular exercise routine may reduce the tendency towards thrombus formation.

Plasma markers of activated hemostasis in the early diagnosis of acute coronary syndromes

BACKGROUND

Because acute coronary syndromes (ACS) are caused by intracoronary thrombosis, plasma markers of coagulation have relevance for early diagnosis.

AIMS AND OBJECTIVES

To provide a critical review of these studies and specific attempts to close the diagnostic time gap left by traditional plasma markers of heart injury.

METHODS

Studies of ACS patients, with at least one control group, were included when blood samples were taken within 24 h after first symptoms prior to medication or intervention. Special attention was paid to studies reporting diagnostic performance, or combination of several markers into a single diagnostic index.

RESULTS

Markers with short plasma half-life (FPA, TAT, etc.) reflect ongoing thrombosis and may identify patients at increased risk. Markers with longer half-life (F1+2, D-Dimer, etc.) may be more useful to indicate a single acute thrombotic event. However, results are highly variable and depend on sampling time, clot property, degree of coronary obstruction and physiological condition. Early diagnostic performance of hemostatic markers was poor even when combined with heart injury markers.

CONCLUSIONS

Early measurement of hemostatic plasma markers in ACS patients provides pathophysiological information and may be helpful in risk stratification or to monitor anticoagulant therapy, but does not seem useful in routine clinical diagnosis of ACS.

Does smoking status influence the effect of physical exercise on fibrinolytic function in healthy volunteers?

Exercise has been reported to simultaneously trigger and protect against sudden death, the so-called "The Paradox of Exercise". Differences in fibrinolytic function appear to exist between chronic and acute exercise. The aim of the present study was to assess the fibrinolytic system after strenuous exercise in healthy people and explored the influence of smoking habit.

METHODS

23 healthy male volunteers were studied (14 non-smokers; 9 current smokers). Citrated plasma blood samples were taken before and 30 minutes after a maximal exercise treadmill test, and levels of tissue type plasminogen activator (t-PA) antigen, plasminogen activator inhibitor (PAI-1) antigen and lipoprotein-a, Lp(a), [all ELISA] were measured as indices of fibrinolytic function.

RESULTS

Smokers had higher body mass index and higher heart rate at baseline than non smokers (p = 0.046 and p = 0.001, respectively). At baseline, smokers showed increased plasma Lp(a) levels than non smokers (p = 0.04), with no differences in t-PA and PAI-1 antigen levels. Following the exercise treadmill test, smokers had a shorter exercise duration and lower exercise capacity than non smokers (p = 0.008 and p = 0.004, respectively). This was associated with a reduction in t-PA antigen levels in the whole study population, (p = 0.048) without differences in PAI-1 levels, with no significant differences between smokers and non smokers. Lp(a) levels were also significantly reduced (p = 0.0001).

CONCLUSIONS

Acute exercise alters plasma tPA antigen and Lp(a) levels, but there was no significant effect of smoking status in healthy subjects.

Nicotine induces tissue factor expression in cultured endothelial and smooth muscle cells

BACKGROUND AND OBJECTIVES

Cigarette smoking is associated with an increased risk to develop myocardial infarction and ischemic stroke. However, the mechanisms responsible for these effects are still poorly understood.

AIM

To investigate whether nicotine, the major component of cigarette smoking, and its main metabolite, cotinine, might induce a pro-thrombotic state via stimulation of tissue factor (TF) expression in two cell population widely represented in the arterial wall such as endothelial cells (ECs), and smooth muscle cells (SMCs).

METHODS AND RESULTS

Incubation of ECs and SMCs with nicotine and cotinine induced TF expression in both cell types in a dose-dependent fashion, exerting its effect at the transcriptional level, as demonstrated by semiquantitative and by real-time PCR. Nicotine- and cotinine-induced TF expression was mediated by the activation of the transcription factor, nuclear factor-kappa B (NF-kappaB), as demonstrated by electrophoretic mobility shift assay and by the suppression of TF expression by the NF-kappaB inhibitor, pyrrolidine dithio carbamate ammonium.

CONCLUSIONS

These data indicate that nicotine and cotinine exert direct effects on ECs and SMCs, shifting them toward a pro-thrombotic state via induction of TF expression. These effects on cells of the vessel wall might explain, at least in part, the deleterious cardiovascular consequences of cigarette smoking.

Systemic lupus erythematosus in a multiethnic US cohort (LUMINA). XXV. Smoking, older age, disease activity, lupus anticoagulant, and glucocorticoid dose as risk factors for the occurrence of venous thrombosis in lupus patients

OBJECTIVE

Venous thrombosis is a relatively frequent and serious complication in systemic lupus erythematosus (SLE) that has been associated with the presence of antiphospholipid antibodies (aPL). However, venous thrombotic events can also be seen in patients without aPL, and only a few patients with aPL develop venous thrombosis. This study was carried out to ascertain other factors contributing to the development of venous thrombosis in SLE.

METHODS

Patients with SLE, ages > or = 16 years with < or = 5 years disease duration and of Hispanic, African American, or Caucasian ethnicity, from LUMINA (LUpus in MInorities, NAture versus nurture), a multiethnic, longitudinal study of outcome, were studied. Selected socioeconomic/demographic, clinical, laboratory, and treatment-exposure variables were compared between patients who developed and those who did not develop venous thrombotic events. Significant and clinically relevant variables were then entered into different multivariable models (Cox proportional hazards and unconditional stepwise logistic regression) to identify independent risk factors associated with the primary outcome. In another model, only patients who developed an event after enrollment (time 0) in the cohort were included.

RESULTS

Of 570 LUMINA patients, 51 developed at least 1 venous thrombotic event after SLE diagnosis. In univariable analyses, smoking (P = 0.020), shorter disease duration at time 0 (P = 0.017), serum levels of total cholesterol, low-density lipoprotein, and triglycerides (all P < 0.0001), and presence of lupus anticoagulant (LAC) (P = 0.045) were associated with venous thrombotic events. Survival analyses showed a time-dependent significant association of the primary outcome with smoking (P = 0.008) and a borderline significant association with the presence of LAC (P = 0.070). Multivariable models showed an independent association with smoking, age at time 0, disease activity over time, LAC, mean dose of glucocorticoids, and shorter disease duration at time 0.

CONCLUSION

Venous thrombotic events occur early in the course of SLE. Our data confirm the association between LAC and venous thrombotic events. Smoking, shorter disease duration, older age, disease activity over time, and higher mean daily glucocorticoid dose were identified as additional risk factors for the development of this vascular complication. These findings may have implications for the management of patients with SLE.

Associations between cigarette smoking, pipe/cigar smoking, and smoking cessation, and haemostatic and inflammatory markers for cardiovascular disease

AIMS

To examine the associations between cigarette smoking, pipe/cigar smoking, and years since quitting smoking, and inflammatory and haemostatic markers.

METHODS AND RESULTS

A study in 2920 men aged 60-79 with no history of myocardial infarction, angina, stroke, or diabetes, and who were not on warfarin, from general practices in 24 British towns. After adjustment for other major cardiovascular risk factors, compared with never smokers, current cigarette smokers showed significantly higher levels of C-reactive protein (2.53 vs. 1.35 mg/L), white cell count (7.92 vs. 6.42 x 10(9)/L), and fibrinogen (3.51 vs. 3.13 g/L). They also showed higher levels of haematocrit, blood and plasma viscosity, tissue plasminogen activator antigen, and fibrin D-dimer, and lower levels of albumin. Primary pipe/cigar smokers showed levels similar to never smokers. Ex-cigarette smokers and secondary pipe/cigar smokers showed intermediate levels although secondary pipe/cigar smokers showed higher odds of having elevated white cell count and fibrinogen than ex-cigarette smokers. Most inflammatory and haemostatic levels improved within 5 years of smoking cessation but took over 20 years to revert to levels of never smokers.

CONCLUSION

These findings suggest that activation of inflammation and haemostasis may be potential mechanisms by which cigarette and pipe/cigar smoking increase cardiovascular risk.

Increased incidence of neoplasia of the digestive tract in men with persistent activation of the coagulant pathway

BACKGROUND

Thrombin promotes angiogenesis and cell proliferation in cancer. Whether thrombin turnover influences cancer incidence is unknown.

OBJECTIVES

To explore the relation between the status of the coagulant pathway and cancer incidence by population survey.

METHODS

Of 4,009 middle-aged men clinically free of malignancy, 3052 (76.1%) were recruited. Measurements of hemostatic status were made annually for 4 years, and follow-up for morbidity and mortality was maintained thereafter. Persistent activation of the coagulant pathway was diagnosed when prothrombin fragment 1+2 and fibrinopeptide A concentrations exceeded the upper quartiles of the population distribution in two consecutive annual examinations. Cancer incidence rates in men developing persistent activation (taking the time of onset of activation as baseline) were compared with those in men remaining free of this condition.

RESULTS

Persistent activation of the hemostatic pathway was a distinct entity found in 111 men [43 expected by chance alone (P <0.001)], and associated with activation throughout the coagulation pathway. Total mortality (/1000 person-years) was higher in those with persistent activation than in others (17.1 and 9.7, respectively, P=0.015), owing to a higher mortality from all cancers (11.3 and 5.1, respectively, P=0.01), due in turn largely to a higher mortality from cancers of the digestive tract (6.3 and 1.9, respectively, P=0.004). Trends were similar for non-fatal cancers.

CONCLUSIONS

Persistent activation of the coagulant pathway plays a role in the preclinical phase of cancer and is associated with an increased incidence of clinical malignancy, especially of the digestive tract.

The Significance of Circulating Factor IXa in Blood

The presence of activation peptides (AP) of the vitamin K-dependent proteins in the phlebotomy blood of human subjects suggests that active serine proteases may circulate in blood as well. The goal of the current study was to evaluate the influence of trace amounts of key coagulation proteases on tissue factor-independent thrombin generation using three models of coagulation. With procoagulants and select coagulation inhibitors at mean physiological concentrations, concentrations of factor IXa, factor Xa, and thrombin were set either equal to those of their AP or to values that would result based upon the rates of AP/enzyme generation and steady state enzyme inhibition. In the latter case, numerical simulation predicts that sufficient thrombin to produce a solid clot would be generated in approximately 2 min. Empirical data from the synthetic plasma suggest clotting times of 3-5 min, which are similar to that observed in contact pathway-inhibited whole blood (4.3 min) initiated with the same concentrations of factors IXa and Xa and thrombin. Numerical simulations performed with the concentrations of two of the enzymes held constant and one varied suggest that the presence of any pair of enzymes is sufficient to yield rapid clot formation. Modeling of states (numerical simulation and whole blood) where only one circulating protease is present at steady state concentration shows significant thrombin generation only for factor IXa. The addition of factor Xa and thrombin has little effect (if any) on thrombin generation induced by factor IXa alone. These data indicate that 1) concentrations of active coagulation enzymes circulating in vivo are significantly lower than can be predicted from the concentrations of their AP, and 2) expected trace amounts of factor IXa can trigger thrombin generation in the absence of tissue factor.

Dietary and antismoking advice and ischemic heart disease mortality in men with normal or high fasting triacylglycerol concentrations: a 23-y follow-up study

BACKGROUND

In the Oslo Diet and Antismoking Trial, 1232 high-risk men aged 40-49 y were randomly assigned to either a lifestyle intervention group or a control group for 5 y. The study showed a significant reduction in ischemic heart disease (IHD) events in the intervention group.

OBJECTIVE

Our objective was to examine this cohort 23 y after the start of the trial.

DESIGN

We examined the effect of group assignment on IHD mortality in subjects with a normal (below the median; range: 0.69-2.00 mmol/L; n = 615) or a high (at or above the median; range: 2.01-13.80 mmol/L; n = 617) fasting triacylglycerol concentration in 1972-1973 (at inclusion into the study). We recorded vital status on 31 December 1996 and ascertained causes of death by linkage to Statistics Norway.

RESULTS

In the men with a high triacylglycerol concentration, IHD death occurred in 25 (8.13%) subjects in the intervention group and in 44 (14.2%) subjects in the control group (relative risk: 0.57; 95% CI: 0.36, 0.91; P = 0.02). An adjusted Cox proportional hazards model yielded a hazard ratio of 0.56 (95% CI: 0.34, 0.93; P = 0.027). In the men with a normal triacylglycerol concentration, the intervention had no detectable effect on IHD mortality (adjusted hazard ratio: 1.10; 95% CI: 0.66, 1.83; P = 0.7).

CONCLUSIONS

These data suggest that advice to change diet and smoking habits reduced the relative risk of IHD mortality after 23 y in men with high triacylglycerol concentrations. Men with normal triacylglycerol concentrations did not appear to achieve this long-term benefit of lifestyle intervention.

Effects of folic acid supplementation on inflammatory and thrombogenic markers in chronic smokers. A randomised controlled trial

INTRODUCTION

Cigarette smoking may induce pro-inflammatory and pro-thrombotic changes. It is not known whether these abnormalities are caused at least partly by increased homocysteine levels. We investigated whether lowering homocysteine by folic acid supplementation might reduce the plasma concentration of inflammatory and thrombogenic markers in chronic smokers.

MATERIAL AND METHODS

Twenty-four healthy cigarette smokers (age 37.8+/-2.5 years, mean+/-SEM) were randomly assigned to 4 weeks of folic acid 5 mg/day or placebo. The following parameters were measured before and after treatment: (1) markers of inflammation (C-reactive protein, CRP, and white cell count, WCC); (2) blood coagulation screen (Activated Partial Thromboplastin time Ratio, APTR, and International Normalized Ratio, INR); (3) pro-thrombotic markers (fibrinogen, factor VIII coagulant activity, VIII:C, von Willebrand factor, vWF, and D-dimer).

RESULTS

Folic acid induced a significant reduction in homocysteine (10.8+/-0.6 vs. 8.2+/-0.5 micromol/l, p<0.001), plasma fibrinogen (3.15+/-0.14 vs. 2.87+/-0.14 g/l, p<0.05), and D-dimer (102+/-44 vs. 80+/-26 microg/l, p<0.05) concentrations. By contrast, no significant changes were observed in CRP (2.2+/-0.7 vs. 1.7+/-0.7 mg/l), WCC (7.2+/-0.5 vs. 6.8+/-0.5 10(9) cells/l), APTR (0.91+/-0.02 vs. 0.93+/-0.02), INR (0.92+/-0.01 vs. 0.91+/-0.01), vWF (103+/-8 vs. 102+/-9 U/dl), and VIII:C (120+/-8 vs. 107+/-8 U/dl) levels. Changes in folic acid plasma concentrations were significantly and negatively correlated with changes in fibrinogen (r=-0.48, p=0.01) but not with changes in D-dimer (r=-0.15, p=0.5) levels. Changes in plasma homocysteine concentrations did not correlate with changes in either fibrinogen or D-dimer. No significant changes in homocysteine, inflammatory and thrombogenic markers were observed in the placebo group.

CONCLUSIONS

Short-term folic acid supplementation had no significant effects on inflammatory markers but induced a significant reduction in plasma fibrinogen and D-dimer concentrations in healthy chronic smokers. Thus, folic acid might have an anti-thrombotic effect in this high-risk group independent of the homocysteine lowering effect.

Impact of smoking on cancer stage at diagnosis

BACKGROUND

Studies evaluating the relationship between smoking and cancer spread are limited.

METHODS

We studied the relationship between cancer stage at diagnosis (local, regional, or metastatic) and smoking history (current, previous, or nonsmoker). For lung cancer, patterns of spread were also studied.

RESULTS

In a tumor registry for eastern North Dakota, northwestern Minnesota, and northern South Dakota, 11,716 cases were identified from 1986 to 2001. Current smokers (relative risk [RR], 2.11; 95% confidence interval, 1.93 to 2.32; P <.001) and previous smokers (RR, 1.56; 95% confidence interval, 1.42 to 1.72; P <.001) had an increased risk of metastatic disease at diagnosis. Current smokers (RR, 1.39; 95% confidence interval, 1.29 to 1.51; P <.001), but not previous smokers, also had an increased risk of regional disease. An increase in metastatic disease was most evident for prostate cancer (RR, 1.53; P =.003). An increase in regional disease was most evident for head and neck (RR, 3.53; P <.001), prostate (RR, 1.83; P =.030), and breast cancer (RR, 1.22; P =.005). Compared with previous smokers, current smokers with metastatic lung cancer were more likely to have involvement of the brain (33.6% v 23.0%; P =.004), bone marrow, adrenal gland, and pericardium (24.7% v 15.9%; P =.004).

CONCLUSION

Previous or current smoking is a risk factor for increased cancer stage in a wide range of malignancies. Further study is required to determine whether this association is causal.

Protein C pathway impairment in nonsymptomatic cigarette smokers

Increased risk of thrombosis in cigarette smokers implies the existence of an underlying prethrombotic state. It is known that oxidative damage to the endothelium surface occurs in chronic smokers. Protein C activation takes place mostly on the endothelium of small vessels and the anticoagulant activity of protein C requires the presence of lipid membranes that are vulnerable to oxidation. Our objective was to analyze the relationship between smoking and plasma levels of activated protein C, protein C zymogen, activated protein C complexed with serpins, total and free protein S, C4b-binding protein, and thrombomodulin, as well as fibrinogen, fibrinopeptide A, and protease-cleaved antithrombin III. Of the 189 plasma donors used in this study 83 were nonsymptomatic smokers (age range 20-44 years, women/men ratio = 1.13) and 106 were healthy nonsmokers (age range 22-59 years, women/men ratio = 1.36). Smokers had 23.3% lower circulating activated protein C than nonsmokers (p = 0.003) and the differences were more pronounced in males than in females. Protein C levels were also significantly lower in smokers than in nonsmokers (p = 0.034). Correlations were negative between the intensity of smoking and circulating activated protein C levels (r = -0.31, p = 0.004) and between smoking and the ratio of activated protein C to protein C zymogen (r = -0.37, p = 0.001). Positive correlations were found between smoking intensity and fibrinogen (r = 0.21, p = 0.042), or fibrinopeptide A (r = 0.219, p = 0.034). Other parameters tested did not show a statistically significant dose-response for the number of cigarettes smoked. Cigarette smoke dose-dependent hypercoagulability due to acquired activated protein C deficiency could contribute to the increased risk of thrombosis in smokers.

Lifestyle factors and coagulation activation markers: the Caerphilly Study

Coagulation activation markers are being investigated as risk factors for cardiovascular disease; we examined the contribution of several lifestyle factors to variation in plasma levels of several activation markers measured in a population-based study of 1947 men. Smoking, alcohol, body mass index (BMI), leisure and work activity, social class, and use of prescribed medicines were each examined in turn. Specific assays of fibrin D-dimer and von Willebrand factor (vWF) activity showed similar relationships to lifestyle variables as we observed previously for less specific assays of D-dimer and vWF antigen. D-dimer levels increased with age, in smokers and in men taking prescribed medication, and were negatively associated with leisure time activity. vWF activity increased with age and showed a U-shaped distribution with BMI. Factors VIIc and VIIIc and thrombin-antithrombin complexes were associated with BMI, factor VIIIc and prothrombin fragments 1 + 2 (F1 + 2) were associated with age, activated partial thromboplastin time (aPTT) and F1 + 2 were associated with smoking, and aPTT showed a small negative association with alcohol consumption. We conclude that lifestyle modification has the possibility of favourably influencing several of these risk markers. In particular, cigarette smoking has a possibly reversible effect on coagulation activation (measured by F1 + 2 and D-dimer).