Smoking Increases Inflammation and Metalloproteinase Expression in Human Carotid Atherosclerotic Plaques

Relationship between pericoronary fat-attenuation values quantified by coronary computed tomography angiography and coronary artery disease severity

AIM

To explore the relationship between pericoronary fat-attenuation index (FAI) values and coronary artery disease (CAD) severity measured using coronary computed tomography angiography (CCTA).

MATERIALS AND METHODS

This study retrospectively included 428 patients with CAD who were eligible and underwent CCTA at our hospital. CAD severity on CCTA images including obstructive stenosis and extensive lesions, and segment stenosis and involvement score (SSS, SIS), and CAD-RADS classification were assessed. FAI values for left anterior descending (LAD), left circumflex (LCX) branches, and right coronary artery (RCA) were quantified using fully automated software. The relationship between FAI values and CAD severity was assessed using univariate and multivariate regression models.

RESULTS

Univariate analyses showed that sex and current smoking were associated with elevated FAILAD and FAILCX values (all P<0.05), whereas CAD severity was not relevant (all P>0.05). Not only clinical factors such as sex, current smoking, and hypertension were associated with elevated FAIRCA, but also indicators to assess CAD severity including obstructive stenosis, SIS, and SSS were related to it (all P<0.05). Multivariate analysis demonstrated that after correcting for the effects of other conventional cardiovascular risk factors and CCTA imaging features, current smoking was an independent risk factor for elevated FAI values (odds ratio [OR] = 0.569, 0.458, and 0.517; all P<0.05), whereas that SSS (OR=1.041, P=0.027) for elevated FAIRCA values.

CONCLUSION

Following correction for conventional cardiovascular risk factors and imaging characteristics, current smoking was an independent clinical risk factor for elevated FAI values, and SSS was an independent risk factor for elevated FAIRCA values.

The Association of Metabolomic Profiles of a Healthy Lifestyle with Heart Failure Risk in a Prospective Study

Lifestyle has been linked to the incidence of heart failure, but the underlying biological mechanisms remain unclear. Using the metabolomic, lifestyle, and heart failure data of the UK Biobank, we identified and validated healthy lifestyle-related metabolites in a matched case-control and cohort study, respectively. We then evaluated the association of healthy lifestyle-related metabolites with heart failure (HF) risk and the added predictivity of these healthy lifestyle-associated metabolites for HF. Of 161 metabolites, 8 were identified to be significantly related to healthy lifestyle. Notably, omega-3 fatty acids and docosahexaenoic acid (DHA) positively associated with a healthy lifestyle score (HLS) and exhibited a negative association with heart failure risk. Conversely, creatinine negatively associated with a HLS, but was positively correlated with the risk of HF. Adding these three metabolites to the classical risk factor prediction model, the prediction accuracy of heart failure incidence can be improved as assessed by the C-statistic (increasing from 0.806 [95% CI, 0.796-0.816] to 0.844 [95% CI, 0.834-0.854], p-value < 0.001). A healthy lifestyle is associated with significant metabolic alterations, among which metabolites related to healthy lifestyle may be critical for the relationship between healthy lifestyle and HF. Healthy lifestyle-related metabolites might enhance HF prediction, but additional validation studies are necessary.

Nicotine dependence and visceral adiposity as risk factors for the development and severity of carotid artery stenosis

Nicotine dependence (ND) and visceral adiposity are emerging as independent risk factors for cardiovascular diseases, including carotid artery stenosis (CAS). This study aimed to determine the relationship between ND and the contribution of abdominal fat to the onset of CAS, which is indicated by a luminal narrowing of at least 60% as determined by duplex and/or Doppler ultrasound. We prospectively collected data from 60 patients with CAS and 60 age- and gender-matched healthy subjects. The Fagerström Test for Nicotine Dependence (FTND), a common research tool, was used in the study. The original questionnaire was designed to gather social and demographic data. Anthropometric measurements, visceral adiposity index (VAI), and lipid accumulation products (LAP) were used to assess obesity. Most patients showed a high or mild-moderate degree of ND: 46.67% and 35%, respectively. The median visceral adiposity index (VAI) and lipid accumulation product (LAP) in patients was 3.92 and 32.83, respectively. Prolonged smoking duration, increased intensity, and high ND are hallmarks of CAS patients.

The Impact of Tobacco Cigarettes, Vaping Products and Tobacco Heating Products on Oxidative Stress

Cells constantly produce oxidizing species because of their metabolic activity, which is counteracted by the continuous production of antioxidant species to maintain the homeostasis of the redox balance. A deviation from the metabolic steady state leads to a condition of oxidative stress. The source of oxidative species can be endogenous or exogenous. A major exogenous source of these species is tobacco smoking. Oxidative damage can be induced in cells by chemical species contained in smoke through the generation of pro-inflammatory compounds and the modulation of intracellular pro-inflammatory pathways, resulting in a pathological condition. Cessation of smoking reduces the morbidity and mortality associated with cigarette use. Next-generation products (NGPs), as alternatives to combustible cigarettes, such as electronic cigarettes (e-cig) and tobacco heating products (THPs), have been proposed as a harm reduction strategy to reduce the deleterious impacts of cigarette smoking. In this review, we examine the impact of tobacco smoke and MRPs on oxidative stress in different pathologies, including respiratory and cardiovascular diseases and tumors. The impact of tobacco cigarette smoke on oxidative stress signaling in human health is well established, whereas the safety profile of MRPs seems to be higher than tobacco cigarettes, but further, well-conceived, studies are needed to better understand the oxidative effects of these products with long-term exposure.

Echo-tracking evaluation of changes in common carotid artery wall elasticity after smoking cessation

The aim of this study was to explore changes in the common carotid arterial wall elasticity after smoking cessation. Carotid artery ultrasonographic examination was performed in 136 patients, then 1 or 2 years after smoking cessation. We used echo-tracking (ET) to measure stiffness index (β), pressure-strain elasticity modulus (Ep), arterial compliance (AC), augmentation index (AI), and local pulse wave velocity (PWVβ). Patients were divided into four groups based on whether or not they successfully stopped smoking (groups M and N, respectively) and whether (groups M2 and N2, respectively) or not (groups M1 and N1, respectively) they showed comorbidities. In group M1, β, Ep and PWVβ were lower at 1 year than before smoking cessation, while AC and AI did not change. At 2 years, β, Ep, PWVβ, and AC, but not AI, improved further. In group M2, β, Ep, and PWVβ decreased at 2 years, whereas AC and AI did not change. In groups N1 and N2, none of the variables changed significantly. ET can be used quantitatively to evaluate the impact of smoking cessation on the elasticity of the common carotid artery wall.

Impact of Tobacco Versus Electronic Cigarette Smoking on Platelet Function

Electronic cigarettes (E-cigarettes) have become popular as substitutes for conventional tobacco cigarettes or to aid quitting, but little is known about the potential risks to cardiovascular health for smokers and nonsmokers. We sought to compare the impact of E-cigarettes with conventional cigarettes on platelet function in healthy adult smokers and nonsmokers. A crossover single-blind study in 40 healthy participants (20 smokers, 20 nonsmokers, matched for age and sex) was conducted. Each participant smoked a conventional cigarette then returned 1 week later to vape a study E-cigarette with the same nominal nicotine content. Blood samples were drawn shortly before and 5 minutes after each episode and analyzed for platelet aggregation, soluble CD40-ligand (sCD40L) and soluble P-selectin (sP-selectin). At baseline, smokers had significantly higher levels of sCD40L and sP-selectin (all p ≤0.01) than nonsmokers. Within 5 minutes of using either a conventional cigarette or E-cigarette, changes in the levels of sCD40L, sP-selectin, and platelet aggregation (all p ≤0.01) were detectable in both smokers and nonsmokers. In smokers, there were no significant changes in sCD40L and sP-selectin but there was a significant increase in platelet aggregation. In nonsmokers, there was a significant increase in all markers of platelet activation following both cigarette and E-cigarette use. Both traditional and E-cigarettes have short-term effects on platelet activation, although in nonsmokers the use of E-cigarettes had a less important impact. In conclusion, we provide the first comparison data of the acute impact of Tobacco-cigarette and E-cigarette smoking on the platelet function in smokers and nonsmokers.

Echogenicity of the carotid arterial wall in active smokers

This pilot study evaluated associations between carotid wall echogenicity, cardiovascular disease (CVD) risk factors, and three markers of smoking heaviness in a cohort of active smokers. Common carotid artery (CCA) grayscale median (GSM) values were measured from sonographic images. Univariable correlations and exploratory multivariable models were used to determine associations between CCA GSM, CVD risk factors, and measures of smoking heaviness. CCA GSM was measured in 162 smokers and was correlated inversely with cigarettes smoked/day (r=-0.16, p=0.048), pack-years (r=-0.204, p=0.009), CVD risk factors such as age, male sex, waist circumference, and low-density lipoprotein cholesterol (all p≤0.03) and positively with high-density lipoprotein cholesterol (p<0.001). Associations between CCA GSM and smoking heaviness markers were not statistically significant after adjustment for traditional risk factors. The results from this pilot study demonstrate the feasibility of measuring the GSM value of the CCA far wall and its association with measures of smoking heaviness and traditional CVD risk factors among current smokers.

Pathological Quantification of Carotid Artery Plaque Instability in Patients Undergoing Carotid Endarterectomy

BACKGROUND

Unstable atherosclerotic carotid plaques cause cerebral thromboemboli and ischemic events. However, this instability has not been pathologically quantified, so we sought to quantify it in patients undergoing carotid endarterectomy (CEA).Methods and Results:Carotid plaques were collected during CEA from 67 symptomatic and 15 asymptomatic patients between May 2015 and August 2016. The specimens were stained with hematoxylin-eosin and elastica-Masson. Immunohistochemistry was performed using an endothelial-specific antibody to CD31, CD34 and PDGFRβ. The histopathological characteristics of the plaques were studied. By multiple-variable logistic regression analysis, plaque instability correlated with the presence of plaque rupture [odds ratio (OR), 9.75; P=0.013], minimum fibrous cap thickness (OR per 10 μm 0.70; P=0.025), presence of microcalcifications in the fibrous cap (OR 7.82; P=0.022) and intraplaque microvessels (OR 1.91; P=0.043). Receiver-operating characteristics analyses showed that these factors combined into a single score diagnosed symptomatic carotid plaques in patients with carotid artery stenosis with a high level of accuracy (area under the curve 0.92; 95% confidence interval 0.85-0.99 vs. asymptomatic).

CONCLUSIONS

This analysis of carotid plaque instability strongly suggested that the diagnostic scoring of carotid plaque instability improves the understanding and treatment of carotid artery disease in patients undergoing CEA.

P2X7 receptor antagonism modulates IL-1β and MMP9 in human atherosclerotic vessels

In atherosclerosis, matrix metallopeptidases (MMPs) contribute to plaque rupture through weakening of the fibrous cap. Pleiotropic P2X purinoceptor 7 (P2X7), expressed in the carotid plaque (PL), is involved in interleukin 1 beta (IL-1β) release that may influence MMP9 generation, thus their possible modulation through acting on P2X7 was investigated. P2X7-related machinery was characterized and the effects of P2X7 antagonists (A740003, KN62) and MMPs inhibitors (Batimastat, Ro28-2653) were studied in ex-vivo tissue cultures of human PL’s vs. non-atherosclerotic internal mammary artery (IMA) by using molecular biology, immune-biochemical and microscopy methodologies. We highlighted atherosclerosis-related differences between PLs and IMAs molecular patterns, and their responsivity to P2X7 antagonism. High IL-1β tissue content was associated with PLs morphology and instability/vulnerability. We demonstrated that A740003, but not KN62, decreased IL-1β and MMP9 independently from NLR family pyrin domain containing 3, but in relationship with patient’s smoking status. Acting downstream P2X7 by MMPs inhibitors, diminished IL-1β mRNA without transcriptional effect at MMP9, possibly because the assumption of statin by patients. These data firstly demonstrated A740003 suitability as a specific tool to decrease inflammatory status in human vessels and might support the design of studies applying P2X7 antagonists for the local targeting and tailored therapy of atherosclerosis.

Cigarette Smoking and Carotid Plaque Echodensity in the Northern Manhattan Study

BACKGROUND

We sought to determine the association between cigarette smoking and carotid plaque ultrasound morphology in a multiethnic cohort.

METHODS

We analyzed 1,743 stroke-free participants (mean age 65.5 ± 8.9 years; 60% women; 18% white, 63% Hispanic, 19% black; 14% current and 38% former smokers, 48% never smoked) from the Northern Manhattan Study using an ultrasound index of plaque echodensity, the Gray-Scale Median (GSM). Echolucent plaque (low GSM) represents soft plaque and echodense (high GSM) more calcified plaque. The mean GSM weighted by plaque area for each plaque was calculated for those with multiple plaques. Quintiles of GSM were compared to no plaque. Multinomial logistic regression models were used to assess associations of cigarette smoking with GSM, adjusting for demographics and vascular risk factors.

RESULTS

Among subjects with carotid plaque (58%), the mean GSM scores for quintiles 1-5 were 48, 72, 90, 105, and 128, respectively. Current smokers had over a two fold increased risk of having GSM in quintile 1 (odds ratio (OR) = 2.17; 95% confidence interval (CI), 1.34-3.52), quintile 2 (OR = 2.33; 95% CI, 1.42-3.83), quintile 4 (OR = 2.05; 95% CI, 1.19-3.51), and quintile 5 (OR = 2.13; 95% CI, 1.27-3.56) but not in quintile 3 (OR = 1.18; 95% CI, 0.67-2.10) as compared to never smokers in fully adjusted models. Former smokers had increased risk in quintile 2 (OR = 1.46; 95% CI, 1.00-2.12), quintile 3 (OR = 1.56; 95% CI, 1.09-2.24), quintile 4 (OR = 1.66; 95% CI, 1.13-2.42), and quintile 5 (OR = 1.73; 95% CI, 1.19-2.51), but not in quintile 1 (OR = 1.05; 95% CI, 0.72-1.55).

CONCLUSIONS

A nonlinear, V-shaped-like relationship between current cigarette smoking and plaque echodensity was observed. Former smokers were at the highest risk for plaques in high GSM quintiles. Thus, current smokers were more likely to have either soft or calcified plaques and former smokers were at greater risk of having only echodense plaques when compared to those who have never smoked. Further research is needed to determine if plaque morphology mediates an association between smoking and clinical vascular events.

Attenuated predictive power of a normal myocardial perfusion scan in young smokers

BACKGROUND

The negative predictive value of a normal myocardial perfusion image (MPI) for myocardial infarction or cardiac death is very high. However, it is unclear whether a normal MPI, reflecting non-compromised blood flow in the stable state, would have the same prognostic implications in smokers as in patients who do not smoke.

METHODS

The incidence of total mortality, cardiovascular mortality, and myocardial infarction was evaluated in 11,812 subjects (14.6% of whom were current smokers at the time of the study) with a normal MPI study and no past history of coronary artery disease during the period 1997 to 2008.

RESULTS

During an average follow-up of 72.4 ± 32.4 months the risk for an acute myocardial infarction in current smokers was approximately 50% higher than the corresponding risk in non-smokers, despite a younger average age. Cox proportional regression models show that current smoking was associated with an increased hazard rate for the composite endpoint below age 60 (HR=2.09, 95%CI 1.43-3.07, p<0.001), but not at older ages (HR=1.16, 95% CI 0.81-1.66, p=0.4).

CONCLUSIONS

In individuals below age 60, but not at older ages, current smoking is associated with increased short- and long-term risk of cardiac death and acute myocardial infarction even in subjects with a normal MPI.

Smoking and Cardiovascular Disease

Smoking represents one of the most important preventable risk factors for the development of atherosclerosis. The present review aims at providing a comprehensive summary of published data from clinical and animal studies, as well as results of basic research on the proatherogenic effect of smoking. Extensive search and review of literature revealed a vast amount of data on the influence of cigarette smoke and its constituents on early atherogenesis, particularly on endothelial cells. Vascular dysfunction induced by smoking is initiated by reduced nitric oxide (NO) bioavailability and further by the increased expression of adhesion molecules and subsequent endothelial dysfunction. Smoking-induced increased adherence of platelets and macrophages provokes the development of a procoagulant and inflammatory environment. After transendothelial migration and activation, macrophages take up oxidized lipoproteins arising from oxidative modifications and transdifferentiate into foam cells. In addition to direct physical damage to endothelial cells, smoking induces tissue remodeling, and prothrombotic processes together with activation of systemic inflammatory signals, all of which contribute to atherogenic vessel wall changes. There are still great gaps in our knowledge about the effects of smoking on cardiovascular disease. However, we know that smoking cessation is the most effective measure for reversing damage that has already occurred and preventing fatal cardiovascular outcomes.

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.

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.

Tissue inhibitor of matrix metalloproteinases 4 (TIMP4) in a population of young adults: relations to cardiovascular risk markers and carotid artery intima-media thickness. The Cardiovascular Risk in Young Finns Study

OBJECTIVES

The tissue inhibitor of metalloproteinases 4 (TIMP4) is present in significant amounts in human atherosclerotic coronary artery lesions, but its relations with the early pathogenesis of atherosclerotic changes have not been clarified. We studied the associations of circulating TIMP4 with pre-clinical markers of atherosclerosis and traditional cardiovascular risk factors by using longitudinal data on carotid artery intima-media (cIMT) thickness in a population-based cohort of asymptomatic young adult Finns.

METHODS

Data on cIMT, plasma TIMP4, lipids, CRP, blood pressure, BMI, smoking status and daily alcohol intake were obtained from 980 24-39 year-old participants in 2001. The 6-year follow-up in cIMT measurements were performed in 2007 for 769 participants.

RESULTS

Plasma TIMP4 concentrations (mean ± SD) were 2.3 ± 1.7 ng/mL in men and 2.5 ± 1.8 ng/mL in women. Age, LDL-cholesterol, BMI and systolic blood pressure were directly associated with TIMP4 concentration. In a multivariable model, the independent determinants of TIMP4 included systolic blood pressure (p = 0.008) and daily smoking (p = 0.009), both being inversely associated with TIMP4. These two baseline variables explained 1.5% of the variation in TIMP4. TIMP4 was significantly and inversely associated with cIMT measured 6 years later (beta =- 0.0135, p = 0.01) explaining 0.7% of the variability of cIMT.

CONCLUSION

In young apparently healthy adults, circulating TIMP4 concentration was independently and inversely associated with cIMT, a marker of vascular structure and function.

Effects of cigarette smoking, metabolic syndrome and dehydroepiandrosterone deficiency on intima-media thickness and endothelial function in hypertensive postmenopausal women

Background

Cigarette smoking is a major risk factor of atherosclerosis. The aim of this study was to assess the relationship between smoking and arterial hypertension as well as endothelial dysfunction in postmenopausal women without clinically manifested symptoms of atherosclerosis.

Material/Methods

The study groups consisted of 35 current smokers and 45 nonsmokers. The thickness of intima-media complex (IMT), a marker of atherosclerosis, was measured in carotid arteries. Plasma concentrations of fasting glucose, insulin, lipoproteins, inflammatory markers (tumor necrosis factor-alpha, intercellular adhesion molecule-1), matrix metalloproteinases (metalloproteinase-9, tissue inhibitor of metalloproteinase-1), insulin, and dehydroepiandrosterone sulfate (DHEA-S) were measured.

Results

Smokers compared with nonsmokers showed lower fasting glucose levels in blood (87.0±10.9 and 93.2±13.6 mg/dl, p<0.05), higher mean systolic (131.1±15.9 vs. 123.0±10.9 mm Hg, p<0.05) and diastolic (81.7±11.4 vs. 75.2±9.2 mm Hg, p<0.05) blood pressure during daytime, and higher average heart rate during the daytime (78.2±9.3/min vs. 71.5±9.5/min, p<0.01) and at night (67.2±10.6/min vs. 61.7±7.7/min, p<0.05), respectively. The IMT in the right carotid artery was significantly higher in smokers than in nonsmokers (0.96±0.16 mm vs. 0.82±0.21, p<0.05) and was positively correlated with smoking intensity (R=0.36) and habit duration (R=0.35). The comparison of inflammatory markers, metalloproteinases, and DHEA-S concentrations in plasma did not reveal significant differences between the 2 groups. A significant negative correlation between DHEA-S concentration in plasma and IMT in right carotid artery was found in smokers.

Conclusions

Smoking in hypertensive postmenopausal women is associated with lower fasting blood glucose and BMI values, but higher arterial pressure and heart rate, and increases in IMT in right carotid artery.

Relationships and Inflammation across the Lifespan: Social Developmental Pathways to Disease

There are well documented links between close relationships and physical health, such that those who have supportive close relationships have lower rates of morbidity and mortality compared to those who do not. Inflammation is one mechanism that may help to explain this link. Chronically high levels of inflammation predict disease. Across the lifespan, people who have supportive close relationships have lower levels of systemic inflammation compared to people who have cold, unsupportive, conflict-ridden relationships. Not only are current relationships associated with inflammation, but past relationships are as well. In this article, we will first review the literature linking current close relationships across the lifespan to inflammation. We will then explore recent work showing troubled past relationships also have lasting consequence on people's inflammatory levels. Finally, we will explore developmental pathways that may explain these findings.

Changes in the activity of connective tissue matrix enzymes in the metabolic syndrome

INTRODUCTION

Early atherosclerotic changes in the endothelium associated with metabolic syndrome are generated with the participation of inflammatory cells, cytokines and enzymes of the extracellular matrix. The study is aimed at a comparison between the activity of inflammatory agents, tumour necrosis factor α (TNF-α) and the enzymes of the connective tissue matrix in the blood of healthy female patients as well as those suffering from the metabolic syndrome.

MATERIAL AND METHODS

The examination included 35 women with metabolic syndrome (MS). The control group (C) comprised 35 healthy women. Lipidogram, C-reactive protein level (CRP), fasting glucose level (FGL), matrix metalloproteinase (MMP)-8 and -9 activity, tissue inhibitor of metalloproteinase-1 (TIMP-1) and TNF-α levels in blood were determined.

RESULTS

As compared with the control group, the level of inflammatory factors and the activity of extracellular matrix enzymes in the metabolic syndrome were statistically higher (p < 0.05) and concerned the following parameters: TNF-α (pg/ml): MS 6.59 ±3.18, C 4.78 ±2.91; CRP (mg/dl): MS 2.18 ±2.04, C 1,26 ±1.35; TIMP-1 (ng/ml): MS 265.5 ±2.9, C 205.4 ±72.6; MMP-9 (ng/ml): MS 198.2 ±138.6, C 138.6 ±116.1. Statistically significant correlations were also found between TIMP-1 and the following factors: BMI (R = 0.400, p < 0.001), waist/hip ratio (WHR) (R = 0.278, p < 0.05), waistline (R = 0.417, p < 0.001), FGL (R = 0.290, p < 0.05), HDL cholesterol (R = -0.253, p < 0.05) and triglycerides (R = 0.269, p < 0.05).There were positive correlations of MMP-9 with FGL (R = 0.446, p < 0.001) and waistline (R = 0.260, p < 0.05); MMP-8 with FGL (R = 0.308, p < 0.05); and CRP with BMI (R = 0.370, p < 0.01), WHR (R = 0.325, p < 0.01) and waistline (R = 0.368, p < 0.01).

CONCLUSIONS

Metabolic syndrome is connected with higher activity of cytokines (TNF-α), inflammatory markers (CRP) and matrix enzymes (MMP-9, MMP-8, TIMP-1).

Association of high-sensitivity C-reactive protein with de novo major depression

BACKGROUND

Although there is cross-sectional evidence that changes in the immune system contribute to the pathophysiology of depression, longitudinal data capable of elucidating cause and effect relationships are lacking.

AIMS

We aimed to determine whether subclinical systemic inflammation, as measured by serum high-sensitivity C-reactive protein (hsCRP) concentration, is associated with an increased risk of de novo major depressive disorder.

METHOD

Major depressive disorder was diagnosed using a clinical interview (SCID-I/NP). This is a retrospective cohort study; from a population-based sample of 1494 randomly selected women recruited at baseline during the period 1994-7, 822 were followed for a decade and provided measures of both exposure and outcome. Of these women, 644 (aged 20-84 years) had no prior history of depression at baseline and were eligible for analysis.

RESULTS

During 5827 person-years of follow-up, 48 cases of de novo major depressive disorder were identified. The hazard ratio (HR) for depression increased by 44% for each standard deviation increase in log-transformed hsCRP (ln-hsCRP) (HR = 1.44, 95% CI 1.04-1.99), after adjusting for weight, smoking and use of non-steroidal anti-inflammatory drugs. Further adjustment for other lifestyle factors, medications and comorbidity failed to explain the observed increased risk for depression.

CONCLUSIONS

Serum hsCRP is an independent risk marker for de novo major depressive disorder in women. This supports an aetiological role for inflammatory activity in the pathophysiology of depression.

Association between matrix metalloproteinase-10 concentration and smoking in individuals without cardiovascular disease

INTRODUCTION AND OBJECTIVES

Smoking is an important cardiovascular risk factor whose underlying mechanism is incompletely understood. However, it has been suggested that alterations in the balance between synthesis and degradation of the extracellular matrix (ECM) may play a role. The aim of this study was to determine whether there is an independent association between smoking and the concentration of circulating metalloproteinases (MMPs) in individuals without cardiovascular disease.

METHODS

Metabolic parameters, the carotid intima-media thickness (IMT), inflammatory markers (fibrinogen, C-reactive protein and interleukin-6), markers of endothelial damage (e.g., von Willebrand factor), and the concentration of MMP-1, -9 and -10 and tissue inhibitor of metalloproteinase-1 (TIMP-1) were assessed in 400 asymptomatic individuals with cardiovascular risk factors. Subjects were divided into non-smokers (n=195), smokers (n=118) and former smokers (n=87). In addition, global cardiovascular risk was determined from PROCAM and REGICOR scores.

RESULTS

Both MMP-1 and MMP-10 concentrations were significantly higher in smokers than non-smokers (P< .05 and P< .001, respectively), though there was no difference in the levels of MMP-9, TIMP-1, IMT and other inflammatory parameters. There were positive correlations between the MMP-10 concentration and PROCAM and REGICOR scores (P< .001). Multivariate analysis showed that there was still an association between smoking and the MMP-10 concentration after adjustment for age, sex and other cardiovascular risk factors (P< .001). Multiple regression analysis showed that smoking accounted for 28% of the variability in the MMP-10 concentration.

CONCLUSIONS

There was an independent association between smoking and the MMP-10 concentration in asymptomatic individuals. This relationship between MMP-10 and the ECM may indicate a mechanism through which this MMP contributes to smoking-related atherosclerosis.

Inflammation at the molecular interface of atherogenesis: an anthropological journey

Despite the multifactorial nature of atherosclerosis, substantial evidence has established inflammation as an often surreptitious, yet critical and unifying driving force which promotes disease progression. To this end, research has defined molecular networks initiated by cytokines, growth factors and other pro-inflammatory molecules which promote hallmarks of atherosclerosis such as endothelial dysfunction, macrophage infiltration, LDL oxidation, cell proliferation and thrombosis. Although commonly associated with risk factors such as dyslipidemia, diabetes and hypertension, the global etiology of atherosclerosis may be alternatively attributed to underlying anthropological pressures. The agricultural, industrial and technological revolutions produced alterations in dietary, social and economic factors which have collectively exaggerated the exposure of the human genome to environmental stimuli. Furthermore, advances in sanitation, nutrition, and medicine have increased the lifespan of humans, effectively prolonging blood vessel exposure to these factors. As a result, the vasculature has become conditioned to respond to injury with what is arguably an overzealous immunological response; thus setting the stage for the prevalence of cardiovascular disease, including atherosclerotic plaque development in Western populations. Evidence suggests that each of these alterations can be linked to specific mediators in the inflammatory process. Integration of these factors with an inflammation-based hypothesis of atherosclerosis has yet to be extrapolated to observations in the realms of basic and clinical sciences and is the focus of this review.

Bioactivation of Polycyclic Aromatic Hydrocarbon Carcinogens within the vascular Wall: Implications for Human Atherogenesis

Atherogenesis is a complex pathogenetic process involving a variety of structural and functional deficits within the arterial wall that culminate in the formation of fibrous atherosclerotic plaques. Cigarette smoking is potentially the most remediable contributor to cardiovascular mortality and morbidity. Among the 4000 plus chemicals present in tobacco and tobacco smoke, polycyclic aromatic hydrocarbons (PAHs) have been firmly implicated in the etiology of atherosclerosis in experimental model systems. However, the molecular mechanisms responsible for PAH-induced vascular injury are not well understood. In this review, we have focused on the mechanisms of bioactivation of PAHs in the vas-culature, and the possible role(s) of cytochrome P4501A and 1B enzymes in the formation of PAH-DNA adducts within the vessel wall, a phenomenon that may contribute to the development of atherosclerotic plaques in humans.

Matrix metalloproteinases and atherogenesis in dependence of age

BACKGROUND

Changes in the proteoglycan metabolism of the intima of arteries belong to the initial lesions of atherosclerosis (AS). The accumulation of proteoglycans, alterations of pericellular glycoproteins and modulations of collagen turnover also play a fundamental role in the progression of AS. They influence lipid retention, cell behavior and calcinosis. The decisive role played by the matrix metalloproteinases (MMPs) and their inhibiting factors (tissue inhibitors of metalloproteinases [TIMPs]) in these processes is not yet fully understood and therefore the subject of this overview. The causes of the abrupt change of a long-term existing stabile AS to a vulnerable plaque as well as the participation of age-related vascular wall remodeling in the progression of AS also remain open questions.

DISCUSSION

Apart from the well-known risk factors for AS, less well-known influences like the disturbances of gene expression in vascular smooth muscle cells affect an MMP/TIMP imbalance. The various consequences of this imbalance range from intima cell proliferation as an early change in AS as well as accelerated progression to the destabilization of fibrous plaques by increased collagenolysis as well as the formation of aneurysms. Infectious or toxic influences may trigger these mechanisms; an involvement of age-related vessel wall changes should also be considered. The prognostic significance of circulating MMP concentrations for the existence of instabile plaques are of great interest, as is the plaque stabilizing effect of statins by suppression of MMPs.

CONCLUSIONS

MMPs navigate the behavior of vascular wall cells in different AS stages, in adaptive remodeling, in normal aging and in non-atherosclerotic vessel disease. The clinical relevance of a disturbance in the MMP/TIMP balance is demonstrated firstly by the initiation of AS due to migration and proliferation of intima cells and secondly in the collagenolysis, necrotic transformation and apoptosis of existing fibrous lesions resulting in instabile rupture proned plaques. Investigations into the genetic typing of MMPs and the results of experimental gene deficiency models have significantly contributed to the clarification of these facts.

Global characterization of coronary plaque rupture phenotype using three-vessel intravascular ultrasound radiofrequency data analysis

AIMS

To compare the global characteristics of patients with and without evidence of plaque rupture (PR) in their coronary tree and to evaluate the phenotype of ruptured plaques using intravascular ultrasound (IVUS) radiofrequency data analysis (IVUS-VH).

METHODS AND RESULTS

Forty patients underwent three-vessel IVUS-VH interrogation. Twenty-eight PRs were diagnosed in 26 vessels (25.7% of the vessels studied) of 20 patients (50% of the population). Ruptures located in the left anterior descending were clustered in the proximal part of the vessel, whereas ruptures located in the right coronary artery were more distally located (P=0.02). Patients with at least one PR presented larger body mass index (BMI) (28.4+/-3.7 vs. 25.8+/-2.6 kg/m(2), P=0.01) and plaque burden (40.7+/-7.6 vs. 33.7+/-8.4%, P=0.01) than patients without rupture, despite showing similar lumen cross-sectional area (9.6+/-3.3 vs. 9.2+/-2.3 mm(2), P=0.60). Among current smokers, 66.7% presented a PR in their coronary tree. Finally, PR sites showed a higher content of necrotic core compared with minimum lumen area sites (17.48+/-10.8 vs. 13.10+/-6.5%, P=0.03) and a trend towards higher calcified component.

CONCLUSION

Patients with at least one PR in their coronary tree presented larger BMI and worse IVUS-derived characteristics compared with patients without PR.

Exploring the relationships between diabetes and smoking: with the development of glucose equivalent concept for diabetes management

The extent of interaction between smoking and diabetes has been under-appreciated. Smokers had more diabetes, and when diabetes patients smoke, the combined mortality effect was greater than either the addition or multiplication of these two medical problems. Patients seen in the office are usually more interested in reducing blood glucose than in quitting smoking, and yet, smoking caused mortality risks, at a magnitude similar to or more than diabetes. The concept of "glucose equivalent of smoking" was developed to direct more attention to smoking in clinical management. Based on the follow-up observations from a large Asian cohort, the risk of an individual who smokes, from all-cause mortality, was found to be equivalent to an elevation of blood glucose by an average of 41mg/dl for the cohort in general and 68mg/dl for the diabetes in particular. By relating the message of smoking hazards in terms of "glucose equivalent", clinicians will be more alerted to counsel and patients will be more likely to quit. Appreciating this concept has a potential to change the paradigm of diabetes management, to bridge the clinical disconnect between the two, and to provide new ammunition for the diabetes epidemic in Taiwan.

The hypothalamic–pituitary–adrenal (HPA) axis in habitual smokers

Nicotine is a strong activator of the hypothalamus pituitary adrenal (HPA) axis. Smoking of only two cigarettes consistently activates the HPA axis of habitual smokers. However, while being a habitual smoker only induces small changes of basal HPA axis activity, smoking induces an attenuated responsiveness of the HPA axis to psychological stress, but not to injection of corticotropin releasing hormone (CRH) or physiological load. The latter points to alterations at hypothalamic or other central structures. The further consequences of decreased HPA axis responsiveness are discussed. Chronic inflammation of the airways is a common consequence of habitual smoking, and smokers often present with low-grade systemic inflammation, which may be mediated by HPA axis alterations. However, habitual smokers' monocytes are reported to show an increased sensitivity towards the inflammation suppressing effects of cortisol, while on the one hand, inflammation of the airways appears to be relatively resistant towards glucocorticoid treatment. In conclusion, this pattern of attenuated cortisol responses and decreased glucocorticoid sensitivity may be causally related to disinhibition of inflammatory processes and thereby further stimulate adverse health outcomes, such as airway inflammation or atherosclerosis.

Smoking, metalloproteinases, and vascular disease

Smoking causes up to 11% of total global cardiovascular deaths. Smoking has numerous effects that may promote atherosclerosis through vascular inflammation and oxidative stress, but the pathogenesis of smoking-related cardiovascular disease remains incompletely understood. The matrix metalloproteinases, a family of endopeptidases that can degrade extracellular matrix components in both physiological and pathophysiological states, play an important role in smoking-associated chronic obstructive pulmonary disease, the second leading cause of smoking attributable mortality. Emerging evidence indicates that the matrix metalloproteinases may also contribute to smoking-related vascular disease. Here we discuss the potential relationship between smoking, matrix metalloproteinases, and acceleration of vascular disease.