Environmental tobacco smoke and carotid arterial stiffness

Hypertension in an ageing population: Diagnosis, mechanisms, collateral health risks, treatments, and clinical challenges

Ageing population is considerably increasing worldwide, which is considered to reflect an improved quality of life. However, longevity in the human lifespan has increased the burden of late-life illnesses including cancer, neurodegeneration, and cardiovascular dysfunction. Of these, hypertension is the most common condition with huge health risks, with an increased prevalence among the elderly. In this review, we outline the current guidelines for defining hypertension and examine the detailed mechanisms underlying the relationship between hypertension and ageing-related outcomes, including sodium sensitivity, arterial stiffness, endothelial dysfunction, isolated systolic hypertension, white coat effect, and orthostatic hypertension. As hypertension-related collateral health risk increases among the elderly, the available management strategies are necessary to overcome the clinical treatment challenges faced among elderly population. To improve longevity and reduce adverse health effects, potential approaches producing crucial information into new era of medicine should be considered in the prevention and treatment of hypertension among elderly population. This review provides an overview of mechanisms underlying hypertension and its related collateral health risk in elderly population, along with multiple approaches and management strategies to improve the clinical challenges among elderly population.

Evaluation of common carotid artery wall stiffness by shear wave elastography in smokers and non-smokers

INTRODUCTION

Smoking is one of the most important preventable causes of cardiovascular diseases. Vascular disease caused by smoking is associated with vascular endothelial damage, platelet aggregation, and adhesion. In our study, we examined the effect of chronic smoking on vessel wall stiffness in smokers and control group by measuring carotid artery wall stiffness by shear wave ultrasonography.

METHODS

Sixty-two smokers of similar ages and genders, and 67 people who never smoked in the last ten years were included as the control group in this cross-sectional study. Arterial wall stiffness over the common carotid arteries of all participants was measured by shear wave elastography (SWE). In addition, each patient's blood pressure, fasting blood glucose, body mass index (BMI), HDL and LDL cholesterol measurements were recorded.

RESULTS

Arterial wall stiffness values in smokers were found to be statistically significantly higher than in non-smokers. The mean of SWE measurements of the smokers was 47.3 ± 6.2 kPa, and that of the control group was 42.9 ± 4 kPa. The mean values of HDL and LDL of the smokers were 46.9 ± 5.6 mg/dL and 147.3 ± 9.3 mg/dL, respectively, and those of the control group were 50.3 ± 5.1 mg/dL and 136.9 ± 5.9 mg/dL. The LDL cholesterol values were statistically significantly higher in smokers compared to the control group, and HDL cholesterol values were statistically significantly lower in smokers.

CONCLUSIONS

In our study, the arterial wall stiffness values measured by the SWE technique were higher in smokers than non-smokers.

Arterial stiffness and biological parameters: A decision tree machine learning application in hypertensive participants

Arterial stiffness, measured by arterial stiffness index (ASI), could be considered a main denominator in target organ damage among hypertensive subjects. Currently, no reported ASI normal references have been reported. The index of arterial stiffness is evaluated by calculation of a stiffness index. Predicted ASI can be estimated regardless to age, sex, mean blood pressure, and heart rate, to compose an individual stiffness index [(measured ASI-predicted ASI)/predicted ASI]. A stiffness index greater than zero defines arterial stiffness. Thus, the purpose of this study was 1) to determine determinants of stiffness index 2) to perform threshold values to discriminate stiffness index and then 3) to determine hierarchical associations of the determinants by performing a decision tree model among hypertensive participants without CV diseases. A study was conducted from 53,363 healthy participants in the UK Biobank survey to determine predicted ASI. Stiffness index was applied on 49,452 hypertensives without CV diseases to discriminate determinants of positive stiffness index (N = 22,453) from negative index (N = 26,999). The input variables for the models were clinical and biological parameters. The independent classifiers were ranked from the most sensitives: HDL cholesterol≤1.425 mmol/L, smoking pack years≥9.2pack-years, Phosphate≥1.172 mmol/L, to the most specifics: Cystatin c≤0.901 mg/L, Triglycerides≥1.487 mmol/L, Urate≥291.9 μmol/L, ALT≥22.13 U/L, AST≤32.5 U/L, Albumin≤45.92 g/L, Testosterone≥5.181 nmol/L. A decision tree model was performed to determine rules to highlight the different hierarchization and interactions between these classifiers with a higher performance than multiple logistic regression (p<0.001). The stiffness index could be an integrator of CV risk factors and participate in future CV risk management evaluations for preventive strategies. Decision trees can provide accurate and useful classification for clinicians.

Arterial stiffness nomogram identification by cluster analysis: A new approach of vascular phenotype modeling

Arterial stiffness, measured by arterial stiffness index (ASI), can be considered as a major denominator in cardiovascular diseases. Thus, it remains essential to highlight patient phenotyping profiles with high ASI values. A nomogram of arterial stiffness was evaluated by calculation of ASI nomogram. Theoretical ASI can be performed according to age, sex, mean blood pressure, and heart rate, allowing to form an individual ASI nomogram [(measured ASI - theoretical ASI)/theoretical ASI]. An ASI nomogram > 0 defined AS. This study investigates among UK Biobank participants without cardiovascular diseases, the hypothesis that K-means cluster analysis can be used to identify homogeneous phenotyping subgroups of participants according to ASI levels and then, the phenotype differences observed between these clusters. ASI nomogram was applied on 132 851 participants. K-means clustering was implemented with 10 clusters (optimal CCC value of 105.246). One cluster showed 100% rate of AS, corresponding to 25 393 participants (41.6% of the AS participants) with ASI nomogram = .26 (.22), ASI = 11.6 (2.3)m/s. A second cluster showed a 100% of non-AS, corresponding to 27 844 participants (38.8% of the participants with no arterial stiffness) with ASI nomogram = -.22 (.13), ASI = 7.1 (1.44)m/s. Threshold values of independent factors for differencing these two clusters were total cholesterol > 5.409 mmol/L (P < .001), triglycerides > 1.286 mmol/L (P < .001), smoking pack years > 11.8 pack/years, CRP > .99 (P < .001), daily alcohol consumption > 1.794 units/days and BMI > 26.641 kg/m² (P < .001). Cluster analysis allowed to highlight homogeneous participants profile with or without AS. Determine the markers differencing these clusters participates in the management of cardiovascular preventive strategies.

Association between serum uric acid and arterial stiffness in a large-aged 40-70 years old population

Arterial stiffness (AS), measured by arterial stiffness index (ASI), is a determinant in cardiovascular (CV) diseases. A high serum uric acid (SUA) level is a known risk factor for CV disease. The authors investigated the relationship between SUA and ASI in the middle-age UK Biobank population study. AS was defined as ASI > 10 m/s. A cross-sectional study was conducted from 126 663 participants. Participants were divided into four quartiles according to SUA levels and sex. Sex multivariate analyses were performed with adjustment for confounding factors. The average ASI for overall participants was 9.3 m/s (SD: 2.9); 9.9 m/s (SD: 2.8) for men and 8.7 m/s (SD: 2.9) for women (P < .001). Men presented higher SUA rate (351.3 mmol/L (SD:67.9)) than women (270.7 mmol/L (SD:64.4)), P < .001. In men multivariate analysis, SUA remained a determinant of AS, with an increase in the strength of the association between the quartiles, Q4 versus Q1, OR = 1.10 [1.05-1.16], P < .001, Q3 versus Q1, OR = 1.09 [1.04-1.14], P < .001 but not between Q2 and Q1 (P = .136). In women, SUA remained significant for AS, with an increase in the strength of the association between the quartiles, Q4 versus Q1, OR = 1.22 [1.15-1.30], P < .001, Q3 versus Q1, OR = 1.13 [1.07-1.19], P < .001 and no difference between Q2 and Q1 (P = .101). When applying continuous SUA values in the multivariate analysis, SUA remained significant (P < .001), with a Youden index value for men = 338.3 mmol/L and for women = 267.3 mmol/L. High SUA levels were associated with AS, suggesting that SUA could be used as a predictor of atherosclerosis.

Arterial Stiffness Determinants for Primary Cardiovascular Prevention among Healthy Participants

Background: Arterial stiffness (AS), measured by arterial stiffness index (ASI), can be considered as a major denominator in cardiovascular (CV) diseases. Thus, it remains essential to highlight the risk factors influencing its increase among healthy participants. Methods: According to European consensus, AS is defined as ASI > 10 m/s. The purpose of this study was to investigate the determinants of the arterial stiffness (ASI > 10 m/s) among UK Biobank normotensive and healthy participants without comorbidities and previous CV diseases. Thus, a cross-sectional study was conducted on 22,452 healthy participants. Results: Participants were divided into two groups, i.e., ASI > 10 m/s (n = 5782, 25.8%) and ASI < 10 m/s (n = 16,670, 74.2%). All the significant univariate covariables were included in the multivariate analysis. The remaining independent factors associated with AS were age (OR = 1.063, threshold = 53.0 years, p < 0.001), BMI (OR = 1.0450, threshold = 24.9 kg/m2, p < 0.001), cystatin c (OR = 1.384, threshold = 0.85 mg/L, p = 0.011), phosphate (OR = 2.225, threshold = 1.21 mmol/L, p < 0.001), triglycerides (OR = 1.281, threshold = 1.09 mmol/L, p < 0.001), mean BP (OR = 1.028, threshold = 91.2 mmHg, p < 0.001), HR (OR = 1.007, threshold = 55 bpm, p < 0.001), Alkaline phosphate (OR = 1.002, threshold = 67.9 U/L, p = 0.004), albumin (OR = 0.973, threshold = 46.0 g/L, p < 0.001), gender (male, OR = 1.657, p < 0.001) and tobacco use (current, OR = 1.871, p < 0.001). Conclusion: AS is associated with multiple parameters which should be investigated in future prospective studies. Determining the markers of increased ASI among healthy participants participates in the management of future CV risk for preventive strategies.

Patient-Specific Inverse Modeling of In Vivo Cardiovascular Mechanics with Medical Image-Derived Kinematics as Input Data: Concepts, Methods, and Applications

Inverse modeling approaches in cardiovascular medicine are a collection of methodologies that can provide non-invasive patient-specific estimations of tissue properties, mechanical loads, and other mechanics-based risk factors using medical imaging as inputs. Its incorporation into clinical practice has the potential to improve diagnosis and treatment planning with low associated risks and costs. These methods have become available for medical applications mainly due to the continuing development of image-based kinematic techniques, the maturity of the associated theories describing cardiovascular function, and recent progress in computer science, modeling, and simulation engineering. Inverse method applications are multidisciplinary, requiring tailored solutions to the available clinical data, pathology of interest, and available computational resources. Herein, we review biomechanical modeling and simulation principles, methods of solving inverse problems, and techniques for image-based kinematic analysis. In the final section, the major advances in inverse modeling of human cardiovascular mechanics since its early development in the early 2000s are reviewed with emphasis on method-specific descriptions, results, and conclusions. We draw selected studies on healthy and diseased hearts, aortas, and pulmonary arteries achieved through the incorporation of tissue mechanics, hemodynamics, and fluid-structure interaction methods paired with patient-specific data acquired with medical imaging in inverse modeling approaches.

Association between Self-Reported Survey Measures and Biomarkers of Second-Hand Tobacco Smoke Exposure in Non-Smoking Pregnant Women

Second-hand tobacco smoke (SHS) causes adverse health outcomes in adults. Further studies are needed to evaluate psychosocial SHS exposure measures in comparison to SHS exposure biomarkers, particularly in pregnant women. This study aimed to compare self-reported SHS exposure to urinary cotinine levels in pregnant women. A cross-sectional correlation design was conducted using a convenience sample of 70 non-smoking pregnant women. Measures included self-reported questionnaires and laboratory confirmation of cotinine levels in the urinary samples. Multiple regression analysis was used to assess the correlation after controlling for potential confounding variables. The average level of urinary cotinine among non-smoking pregnant women was 6.77 ng/mL. Medium-strength correlations were found among psychosocial SHS exposure measures and urine cotinine levels. Questions regarding ‘instances of smoking in front of the individual’ and ‘subjective perceived frequency of SHS exposure in past 7 days’ are feasible items for pregnant women in clinics (particularly the first question). Hence, we suggest that these simple questions should be used to assist pregnant women in reducing the harm associated with SHS exposure.

Is Stiffness Parameter β Useful for the Evaluation of Atherosclerosis?~ Its Clinical Implications, Limitations, and Future Perspectives ~

Atherosclerosis comprises two components, atherosis and sclerosis, characterized by morphological wall thickening and functional stiffening, respectively, of the arterial wall. In recent years, much interest has been directed to the role of functional changes in large arteries, i.e., increased stiffness or decreased elasticity, on the development of cardiovascular diseases. In fact, the clinical evaluation of arterial stiffness is increasingly performed in patients with cardiovascular risk factors. Local arterial stiffness is measured using an ultrasound technique implemented with an echo-tracking system at the common carotid and femoral arteries. Several indices of local arterial stiffness are obtained by ultrasound, among which stiffness parameter β is unique because it is the least affected by blood pressure at the time of measurement. Evidence from cross-sectional studies indicates that increased stiffness parameter β is associated with a number of cardiovascular risk factors, such as older age, smoking, insufficient physical activity, hypertension, obesity, metabolic syndrome, insulin resistance, type 2 diabetes, chronic kidney disease, and comorbid cardiovascular disease. Results from several prospective observational studies also suggest that carotid stiffness parameter β is a useful surrogate marker of cardiovascular events and/or mortality, although the results differ depending on the characteristics of the study subjects. Furthermore, several interventional studies have shown that carotid stiffness parameter β improved after lifestyle modification or drug treatment. In this review, we summarize the current evidence of stiffness parameter β of the carotid artery and discuss its clinical implications as a marker of vascular health or as a predictor of cardiovascular outcomes.

Assessing Patient-Specific Mechanical Properties of Aortic Wall and Peri-Aortic Structures From In Vivo DENSE Magnetic Resonance Imaging Using an Inverse Finite Element Method and Elastic Foundation Boundary Conditions

The establishment of in vivo, noninvasive patient-specific, and regionally resolved techniques to quantify aortic properties is key to improving clinical risk assessment and scientific understanding of vascular growth and remodeling. A promising and novel technique to reach this goal is an inverse finite element method (FEM) approach that utilizes magnetic resonance imaging (MRI)-derived displacement fields from displacement encoding with stimulated echoes (DENSE). Previous studies using DENSE MRI suggested that the infrarenal abdominal aorta (IAA) deforms heterogeneously during the cardiac cycle. We hypothesize that this heterogeneity is driven in healthy aortas by regional adventitial tethering and interaction with perivascular tissues, which can be modeled with elastic foundation boundary conditions (EFBCs) using a collection of radially oriented springs with varying stiffness with circumferential distribution. Nine healthy IAAs were modeled using previously acquired patient-specific imaging and displacement fields from steady-state free procession (SSFP) and DENSE MRI, followed by assessment of aortic wall properties and heterogeneous EFBC parameters using inverse FEM. In contrast to traction-free boundary condition, prescription of EFBC reduced the nodal displacement error by 60% and reproduced the DENSE-derived heterogeneous strain distribution. Estimated aortic wall properties were in reasonable agreement with previously reported experimental biaxial testing data. The distribution of normalized EFBC stiffness was consistent among all patients and spatially correlated to standard peri-aortic anatomical features, suggesting that EFBC could be generalized for human adults with normal anatomy. This approach is computationally inexpensive, making it ideal for clinical research and future incorporation into cardiovascular fluid-structure analyses.

Association between secondhand smoke exposure and hypertension: nearly as large as smoking

: Active smoking is a widely accepted risk factor for cardiovascular disease and is recognized as a major public health problem. Passive smoking, also known as secondhand smoke exposure (SHSE), is thought to have similar cardiovascular consequences and the risk has been postulated to be equivalent to that of active smoking. A major component of this risk involves the connection with chronic hypertension. There are several population-based observational studies investigating the relationship between SHSE and chronic hypertension, all of which demonstrate a positive association. Given that SHSE appears to be a risk factor for chronic hypertension, SHSE should also be a risk factor for hypertensive end-organ disease. Many studies have sought to investigate this relationship, but this has yet to be fully elucidated. In this review, we focus on the current evidence regarding the association between SHSE and hypertension as well as exploration of the links between SHSE and hypertensive end-organ damage.

Relation of secondhand smoke exposure to vascular phenotypes in children and adolescents

BACKGROUND

Subclinical cardiovascular risks of secondhand smoke (SHS) exposure among children and adolescents remains insufficiently described.

METHODS

This was a cross-sectional study of 298 children and adolescents (48.0% male, body mass index: 27.0 ± 8.9 kg/m²), including 49 self-reported cases with SHS. Arterial elasticity and stiffness (distensibility, compliance, incremental elastic modulus [IEM]) were obtained via ultrasound imaging in the abdominal aorta, brachial, and carotid arteries. A one-way analysis of variance compared differences between groups, and multiple linear regression adjusted for covariates.

RESULTS

SHS was associated with lower abdominal aorta diameter distensibility (aDD) (13.4 ± 3.6% vs. 16.0 ± 5.2%, p = 0.009) and abdominal aorta cross-sectional distensibility (aCSD) (28.8 ± 8.3% vs. 35.1 ± 12.2%, p = 0.009), as well as higher abdominal aorta IEM (aIEM) (1241 ± 794 vs. 935 ± 388 mmHg, p = 0.001). After adjustment for covariates, aDD (p = 0.047), aCSD (p = 0.040), and aIEM (p = 0.017) remained significant; this significance persisted with the additional adjustment of percent body fat. Measures of brachial and carotid compliance and distensibility were not associated with SHS.

CONCLUSIONS

SHS was associated with abdominal aorta stiffness; the majority of vascular measures within the brachial and carotid artery remained unaffected following adjustment for covariates, including hypertension and adiposity. SHS may predispose individuals to increased abdominal aorta stiffness, an artery previously reported to exhibit increased susceptibility to atherosclerosis.

Age Differences in the Relationship between Secondhand Smoke Exposure and Risk of Metabolic Syndrome: A Meta-Analysis

Secondhand smoke (SHS), a common environmental exposure factor, has become a serious public health problem. Metabolic syndrome is another worldwide clinical challenge. Our study tried to determine the age differences in the relationship between SHS and the risk of metabolic syndrome. Studies were searched in PubMed and Web of Science from 11 November to 30 November 2018. Eighteen studies were finally included based on inclusion and exclusion criteria. The relationship between SHS and the risk indicators of metabolic syndrome was analyzed. The weighted mean difference (WMD) of fasting plasma glucose (FPG), insulin, body mass index (BMI), and waist circumference (WC), and the standard mean difference (SMD) of total cholesterol, triglycerides, and low- and high-density lipoprotein-cholesterol (LDL-C, HDL-C) were calculated in a meta-analysis. SHS was positively associated with the level of insulin and WC. According to the subgroup analysis based on age difference, SHS was positively associated with FPG in the upper age group, and positively associated with LDL-C and negatively associated with HDL-C in the lower age group. BMI showed a more obvious positive correlation in the adults group than in the children and the teenagers group. In conclusion, the association of metabolic syndrome with SHS varies with age. When exposed to SHS, older people may be more susceptible to glucose metabolic disorder, but younger people may be more susceptible to lipid metabolic disorder.

Influence of environmental tobacco smoke on morphology and functions of cardiovascular system assessed using diagnostic imaging

Exposure to tobacco smoke is a significant problem of environmental medicine. Tobacco smoke contains over one thousand identified chemicals including numerous toxicants. Cardiovascular system diseases are the major cause of general mortality. The recent development of diagnostic imaging provided methods which enable faster and more precise diagnosis of numerous diseases, also those of cardiovascular system. This paper reviews the most significant scientific research concerning relationship between environmental exposure to tobacco smoke and the morphology and function of cardiovascular system carried out using diagnostic imaging methods, i.e. ultrasonography, angiography, computed tomography and magnetic resonance imaging. In the forthcoming future, the studies using current diagnostic imaging methods should contribute to the reliable documentation, followed by the wide-spreading knowledge of the harmful impact of the environmental tobacco smoke exposure on the cardiovascular system.

Environmental Tobacco Smoke and Cardiovascular Disease

Environmental tobacco smoke (ETS) and its sequelae are among the largest economic and healthcare burdens in the United States and worldwide. The relationship between active smoking and atherosclerosis is well-described in the literature. However, the specific mechanisms by which ETS influences atherosclerosis are incompletely understood. In this paper, we highlight the definition and chemical constituents of ETS, review the existing literature outlining the effects of ETS on atherogenesis and thrombosis in both animal and human models, and briefly outline the public health implications of ETS based on these data.

Prediction of carotid intima-media thickness in obese patients with low prevalence of comorbidities by serum copper bioavailability

BACKGROUND AND AIM

Western societies, with growing prevalence, suffer from various metabolic diseases like obesity and hepatic steatosis, better defined as non-alcoholic fatty liver disease, or cardiovascular (CV) diseases that are strictly linked to each other. The association of their occurrence with the altered homeostasis of metals is an intriguing issue. Copper in particular was identified as key player in various metabolic derangements. On these bases, we aimed at investigating the possible association of serum copper levels with an indicator of early CV risk as the intima-media thickness (IMT) of carotid artery and its predictive value in a selected population of obese patients.

METHODS

We performed a cross-sectional study recruiting 100 obese patients characterized by a low prevalence of comorbidities. Ultrasound investigation for hepatic steatosis and IMT evaluation were performed. Serum samples were collected and then analyzed through atomic absorption spectrometry to evaluate their copper content. Possible correlations between copper bioavailability and biochemical, clinical, and anthropometric characteristics of patients were sought.

RESULTS

Age negatively predicted copper serum levels of patients (P = 0.009). However, the most interesting finding is the negative prediction of IMT by the copper serum levels (t = -2.23, P = 0.028, least absolute deviations regression). Factor analysis confirmed the aforementioned inverse correlation and highlighted the strong inverse correlation between smoking and copper serum levels.

CONCLUSION

Our data show that an altered copper bioavailability predicts early atherosclerosis as main CV risk in obese patients with hepatic steatosis detected by ultrasound, shedding some light in this pathological scenario.

Exposure to Cigarette Smoke and the Morphology of Atherosclerotic Plaques in the Extracranial Arteries Assessed by Computed Tomography Angiography in Patients with Essential Hypertension

The aim of the study was to determine the relationship between exposure to cigarette smoke and the morphology of atherosclerotic plaques in the extracranial arteries assessed by computed tomography angiography in patients with hypertension. The study included 61 hypertensive patients: 17 active smokers (group A), 18 non-smokers, declaring environmental exposure to tobacco smoke (group B), and 26 non-smokers, not declaring exposure to cigarette smoke (group C). The number of segments with plaques was significantly higher in group A compared to groups B and C. The number of segments with non-calcified and mixed plaques was significantly higher in group A and group B than in group C. A positive correlation between cigarette-years and the number of segments with atherosclerotic plaques was noted. In summary, both active smoking and environmental exposure to tobacco smoke appear to increase the number of segments of the extracranial arteries with non-calcified and mixed atherosclerotic plaques.

Passive smoking and stroke in men and women: a national population-based case-control study in China

An association between passive smoking and stroke is unclear in China, particularly the association with hemorrhagic stroke. This study included 16205 deaths due to stroke aged ≥30 years and 16205 non-stroke controls randomly selected and frequency-matched to cases on gender and age. Smoking of spouses, defined as ≥1 cigarette per day for up to 1 year, was taken as a measure of exposure to passive smoking of subjects that was retrospectively ascertained by interviewing surviving spouses. After adjustment for variables, passive smoking increased the risk of death by 10% (odds ratio (OR), 1.10; 95% confidence interval (CI), 1.05-1.16) for all strokes, by 10% (OR, 1.10; 95% CI, 1.04-1.16) for hemorrhagic stroke, and by 12% (OR, 1.12; 95% CI, 1.03-1.23) for ischemic stroke, compared with non-exposure. This finding was highly consistent in men or women and in smokers or non-smokers, and was generally consistent among zones of China despite geographic diversity. The risk significantly increased with exposure-years and quantity of cigarettes smoked daily by spouses. This study indicated that passive smoking is associated with deaths from all-type strokes. It is highly advisable for the government to promote strong tobacco prevention and cessation programs and smoke-free environments.

Plausible Roles for RAGE in Conditions Exacerbated by Direct and Indirect (Secondhand) Smoke Exposure

Approximately 1 billion people smoke worldwide, and the burden placed on society by primary and secondhand smokers is expected to increase. Smoking is the leading risk factor for myriad health complications stemming from diverse pathogenic programs. First- and second-hand cigarette smoke contains thousands of constituents, including several carcinogens and cytotoxic chemicals that orchestrate chronic inflammatory responses and destructive remodeling events. In the current review, we outline details related to compromised pulmonary and systemic conditions related to smoke exposure. Specifically, data are discussed relative to impaired lung physiology, cancer mechanisms, maternal-fetal complications, cardiometabolic, and joint disorders in the context of smoke exposure exacerbations. As a general unifying mechanism, the receptor for advanced glycation end-products (RAGE) and its signaling axis is increasingly considered central to smoke-related pathogenesis. RAGE is a multi-ligand cell surface receptor whose expression increases following cigarette smoke exposure. RAGE signaling participates in the underpinning of inflammatory mechanisms mediated by requisite cytokines, chemokines, and remodeling enzymes. Understanding the biological contributions of RAGE during cigarette smoke-induced inflammation may provide critically important insight into the pathology of lung disease and systemic complications that combine during the demise of those exposed.

Cardiovascular Consequences of Childhood Secondhand Tobacco Smoke Exposure: Prevailing Evidence, Burden, and Racial and Socioeconomic Disparities: A Scientific Statement From the American Heart Association

BACKGROUND

Although public health programs have led to a substantial decrease in the prevalence of tobacco smoking, the adverse health effects of tobacco smoke exposure are by no means a thing of the past. In the United States, 4 of 10 school-aged children and 1 of 3 adolescents are involuntarily exposed to secondhand tobacco smoke (SHS), with children of minority ethnic backgrounds and those living in low-socioeconomic-status households being disproportionately affected (68% and 43%, respectively). Children are particularly vulnerable, with little control over home and social environment, and lack the understanding, agency, and ability to avoid SHS exposure on their own volition; they also have physiological or behavioral characteristics that render them especially susceptible to effects of SHS. Side-stream smoke (the smoke emanating from the burning end of the cigarette), a major component of SHS, contains a higher concentration of some toxins than mainstream smoke (inhaled by the smoker directly), making SHS potentially as dangerous as or even more dangerous than direct smoking. Compelling animal and human evidence shows that SHS exposure during childhood is detrimental to arterial function and structure, resulting in premature atherosclerosis and its cardiovascular consequences. Childhood SHS exposure is also related to impaired cardiac autonomic function and changes in heart rate variability. In addition, childhood SHS exposure is associated with clustering of cardiometabolic risk factors such as obesity, dyslipidemia, and insulin resistance. Individualized interventions to reduce childhood exposure to SHS are shown to be at least modestly effective, as are broader-based policy initiatives such as community smoking bans and increased taxation.

PURPOSE

The purpose of this statement is to summarize the available evidence on the cardiovascular health consequences of childhood SHS exposure; this will support ongoing efforts to further reduce and eliminate SHS exposure in this vulnerable population. This statement reviews relevant data from epidemiological studies, laboratory-based experiments, and controlled behavioral trials concerning SHS and cardiovascular disease risk in children. Information on the effects of SHS exposure on the cardiovascular system in animal and pediatric studies, including vascular disruption and platelet activation, oxidation and inflammation, endothelial dysfunction, increased vascular stiffness, changes in vascular structure, and autonomic dysfunction, is examined.

CONCLUSIONS

The epidemiological, observational, and experimental evidence accumulated to date demonstrates the detrimental cardiovascular consequences of SHS exposure in children.

IMPLICATIONS

Increased awareness of the adverse, lifetime cardiovascular consequences of childhood SHS may facilitate the development of innovative individual, family-centered, and community health interventions to reduce and ideally eliminate SHS exposure in the vulnerable pediatric population. This evidence calls for a robust public health policy that embraces zero tolerance of childhood SHS exposure.

Prenatal Air Pollution Exposure and Early Cardiovascular Phenotypes in Young Adults

Exposure to ambient air pollutants increases risk for adverse cardiovascular health outcomes in adults. We aimed to evaluate the contribution of prenatal air pollutant exposure to cardiovascular health, which has not been thoroughly evaluated. The Testing Responses on Youth (TROY) study consists of 768 college students recruited from the University of Southern California in 2007–2009. Participants attended one study visit during which blood pressure, heart rate and carotid artery arterial stiffness (CAS) and carotid artery intima-media thickness (CIMT) were assessed. Prenatal residential addresses were geocoded and used to assign prenatal and postnatal air pollutant exposure estimates using the U.S. Environmental Protection Agency’s Air Quality System (AQS) database. The associations between CAS, CIMT and air pollutants were assessed using linear regression analysis. Prenatal PM₁₀ and PM_2.5 exposures were associated with increased CAS. For example, a 2 SD increase in prenatal PM_2.5 was associated with CAS indices, including a 5% increase (β = 1.05, 95% CI 1.00–1.10) in carotid stiffness index beta, a 5% increase (β = 1.05, 95% CI 1.01–1.10) in Young’s elastic modulus and a 5% decrease (β = 0.95, 95% CI 0.91–0.99) in distensibility. Mutually adjusted models of pre- and postnatal PM_2.5 further suggested the prenatal exposure was most relevant exposure period for CAS. No associations were observed for CIMT. In conclusion, prenatal exposure to elevated air pollutants may increase carotid arterial stiffness in a young adult population of college students. Efforts aimed at limiting prenatal exposures are important public health goals.

The aortic mechanical properties in patients with the essential hypertension environmentally exposed to cigaret smoke

CONTEXT

The impairment of the aortic mechanical features constitutes the independent predictor of all-cause and cardiovascular mortality and morbidity.

OBJECTIVE

The purpose of the present research has been the determination of the influence of the environmental exposure to cigaret smoke on the aortic mechanical properties, namely, the stiffness and elasticity of aorta, in patients with essential hypertension.

MATERIALS AND METHODS

The research has covered 128 people with essential hypertension: 64 nonsmokers, declaring the environmental exposure to cigaret smoke (group A) and 64 nonsmokers declaring the lack of environmental exposure to cigaret smoke selected on the case to case basis (group B). Aortic mechanical properties have been evaluated on the basis of the parameters: aortic stiffness index (AoSI), aortic strain (AoS) and aortic distensibility (AoD).

RESULTS

In group A, the average values of AoSI were significantly higher, and the average values of AoS and AoD significantly lower than in group B. It has been documented that the older age and environmental exposure to cigaret smoke form independent risk factors of increasing the aortic stiffness expressed by higher values of AoSI, whereas the older age, higher pulse pressure (PP) values and environmental exposure to cigaret smoke - independent risk factors of aortic elasticity reduction expressed for the age and "passive smoking" by lower values of AoS and AoD and for PP - lower values of AoD.

CONCLUSION

In patients with essential hypertension, the environmental exposure to cigaret smoke seems to result in impairment of the aortic mechanical properties.

Association of serum cotinine levels and the parameters of vascular structure and function in never-smoking adults

Passive smoking is now recognized to be associated with early arterial damage. The aim of this study was to assess the relationship between secondhand smoke (SHS) exposure, measured objectively by serum cotinine level, and the parameters used to assess vascular structure and function among never smokers in North China. From January 2008 to August 2008, 652 adults aged 20-70 years were enrolled. Brachial-ankle pulse wave velocity (baPWV), ankle-brachial index, and carotid intima-media thickness measurements were performed in all patients. All participants were required to respond to an interviewer-led questionnaire including medical histories and demographic data and to receive blood tests on biochemical indicators. We found that in nonsmokers, higher levels of serum cotinine were positively associated with higher baPWV and brachial pulse pressure after adjusting for heart rate, body mass index, and other confounders. Tests for linear trends for this association were statistically significant. In contrast, no association was present with ankle-brachial index and carotid intima-media thickness. In never smokers, higher SHS exposure measured objectively by serum cotinine levels was found to be associated with brachial pulse pressure and baPWV after adjusting for confounders.

A Comparison of Survey Measures and Biomarkers of Secondhand Tobacco Smoke Exposure among Nonsmokers

OBJECTIVES

Secondhand tobacco smoke (SHS) exposure causes several adverse physical health outcomes. Conceptual differences in survey measures of 'psychosocial' (SHS exposure from smokers in an individual's life) and 'physical' (environments where an individual is exposed to SHS) SHS exposure exist. Few studies have examined the association between psychosocial and physical SHS exposures measures in comparison to biomarkers of SHS exposure.

DESIGN AND SAMPLE

A secondary analysis of cross-sectional data was examined among a convenience sample of 20 adults.

MEASURES

Data included survey items on SHS exposure and hair nicotine and saliva cotinine levels. Spearman analysis was used to assess correlations among variables.

RESULTS

Medium and strong correlations were found among SHS exposure measures with the exception of saliva cotinine levels. Strong correlations were found among and between psychosocial and physical SHS exposure measures. Hair nicotine levels had medium strength associations with only perceived frequency of SHS exposure.

DISCUSSION

As psychosocial measures of exposure were associated with biomarkers, such measures (particularly perceived frequency of SHS exposure) should be added to surveys in addition to physical SHS exposure measures to enhance accuracy of SHS measurement. Future explorations with robust sample sizes should further examine the strength of relationship between psychosocial and physical SHS exposure measures.

Secondhand smoke exposure is associated with increased carotid artery intima-media thickness: the Bogalusa Heart Study

BACKGROUND

Secondhand smoke (SHS) exposure increases cardiovascular disease risk. The objective of this study was to examine the association of SHS exposure in childhood and adulthood with adult arterial thickness.

METHODS

The study cohort consisted of 415 nonsmoking adults (301 whites and 114 blacks; ages 26.2-48.0 years) enrolled in 2004-2010. The arterial wall thickness was measured as common, bulb and internal carotid artery intima-media thickness (IMT). SHS exposure data in childhood and adulthood were obtained by a questionnaire survey.

RESULTS

Increased adult composite carotid IMT was significantly associated with SHS exposure (regression coefficient, β = 53.1 μm, p < 0.001) after adjusting for race, age, gender, education, income, body mass index, systolic blood pressure, LDL cholesterol and triglycerides/HDL cholesterol ratio, with blacks (β = 81.2 μm, p = 0.005) and whites (β = 38.9 μm, p = 0.017) showing the same direction of the association. Furthermore, the SHS exposure in childhood showed a relatively stronger association with increased carotid IMT than the exposure in adulthood based on standardized βs (0.180 vs. 0.106); the same trend in the difference between childhood and adulthood exposure was noted for duration of SHS exposure (0.186 vs. 0.145). The covariates-adjusted composite carotid IMT showed a significant increasing trend by the order of exposure status of none, adulthood only, childhood only and both (p for trend<0.001).

CONCLUSIONS

If the relationship is causal, the associations observed in this study suggest that more awareness should be raised on the dangers of SHS exposure during childhood so that its effect may be mitigated and controlled early in the cardiovascular disease process.

HDL anti-oxidant function associates with LDL level in young adults

OBJECTIVES

The primary objective was to evaluate predictors of HDL anti-oxidant function in young adults.

BACKGROUND

High-density lipoprotein (HDL) cholesterol is considered a protective factor for cardiovascular disease (CVD). However, increased levels are not always associated with decreased cardiovascular risk. A better understanding of the importance of HDL functionality and how it affects CVD risk is needed.

METHODS

Fifty non-Hispanic white subjects from the Testing Responses on Youth (TROY) study were randomly selected to investigate whether differences in HDL anti-oxidant function are associated with traditional cardiovascular risk factors, including carotid intima media thickness (CIMT), arterial stiffness and other inflammatory/metabolic parameters. HDL anti-oxidant capacity was evaluated by assessing its ability to inhibit low-density lipoprotein (LDL) cholesterol oxidation by air using a DCF-based fluorescent assay and expressed as a HDL oxidant index (HOI). The associations between HOI and other variables were assessed using both linear and logistic regression.

RESULTS

Eleven subjects (25%) had an HOI ≥ 1, indicating a pro-oxidant HDL. Age, LDL, high sensitivity C-reactive protein (hsCRP), and paraoxonase activity (PON1), but not HDL, were all associated with HOI level in univariate linear regression models. In multivariate models that mutually adjusted for these variables, LDL remained the strongest predictor of HOI (0.13 increase in HOI per 1 SD increase in LDL, 95% CI 0.04, 0.22). Atherogenic index of plasma, pulse pressure, homocysteine, glucose, insulin, CIMT and measurements of arterial stiffness were not associated with HOI in this population.

CONCLUSIONS

These results suggest LDL, hsCRP and DBP might predict HDL anti-oxidant function at an early age.

Second hand smoke and cardiovascular disease in Low and Middle Income Countries: a case for action

Second hand tobacco smoke (SHS) is an environmental toxin and an established cause of cardiovascular disease in nonsmokers. Smoke free laws reduce SHS and its downstream cardiovascular disease, but until recently evidence to support smoke free law implementation in low and middle income country settings was limited. In 14 low and middle income nations surveyed by the Global Adult Tobacco Survey active smoking prevalence in adults (≥15 years old) was universally higher in males (range 21.6-60.2%) compared with females (0.5-24.4%), and the highest burden of SHS exposure was in women (strong positive association between male/female active smoking ratio and female SHS exposure prevalence). A systematic review was conducted of MEDLINE-indexed studies of self-reported SHS exposure and cardiovascular harms in low or middle income nations. Eight papers reported the association of SHS with ischemic heart disease and four reported the association of SHS with stroke. For all the studies, and almost all sources of SHS surveyed, a strong positive association between SHS and ischemic heart disease (main relative odds ratio range 1.17-2.36) and SHS and stroke (odds ratio or hazard ratio 1.41-1.49). Prevalence of SHS exposure is high in low and middle income nations, especially among women. Epidemiologic evidence supports the conclusion that SHS harms are the same across low, middle and high income nations. Governments have an obligation to protect citizens from SHS exposure, enforcing smoke-free legislation and providing public education about SHS harms.

Secondhand smoke exposure and coronary artery calcification among nonsmoking participants of a population-based cohort

BACKGROUND

Secondhand smoke (SHS) consists of fine particulate matter, carcinogens, and various toxins that affect large parts of the population. SHS increases the risk for acute cardiovascular events and may contribute to the development of atherosclerosis.

OBJECTIVES

We investigated the association of SHS with coronary artery calcification (CAC).

METHODS

In this cross-sectional analysis, we used baseline data (2000-2003) from 1,766 never-smokers without clinically manifested coronary heart disease, 45-75 years of age, from the Heinz Nixdorf Recall Study, an ongoing, prospective, population-based cohort study in Germany. Self-reported frequent SHS at home, at work, and in other places was assessed by questionnaire. CAC scores were derived based on electron-beam computed tomography. We conducted multiple linear regression analysis using exposure to SHS as the explanatory variable and ln(CAC+1) as the response variable. We conducted logistic regression to estimate the odds ratio (OR) for presence of any CAC.

RESULTS

Frequent exposure to SHS was reported by 21.5% of participants. After adjustment for age, sex, and socioeconomic status, CAC + 1 was 21.1% [95% confidence interval (CI): -5.5%, 55.2%] higher in exposed than in unexposed participants. After adjusting for other cardiovascular risk factors, the association was attenuated (15.4%; 95% CI: -9.6%, 47.2%). SHS exposure was also associated with a CAC score > 0 (fully adjusted OR = 1.38; 95% CI: 1.03, 1.84).

CONCLUSIONS

Self-reported frequent exposure to SHS was associated with subclinical coronary atherosclerosis in our cross-sectional study population. Considering the widespread exposure and the clinical relevance of coronary atherosclerosis, this result, if confirmed, is of public health importance.

Long-term exposure to airborne particles and arterial stiffness: the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Increased arterial stiffness could represent an intermediate subclinical outcome in the mechanistic pathway underlying associations between average long-term pollution exposure and cardiovascular events.

OBJECTIVE

We hypothesized that 20 years of exposure to particulate matter (PM) ≤ 2.5 and 10 μm in aerodynamic diameter (PM2.5 and PM10, respectively) would be positively associated with arterial stiffness in 3,996 participants from the Multi-Ethnic Study of Atherosclerosis (MESA) who were seen at six U.S. study sites.

METHODS

We assigned pollution exposure during two decades preceding a clinical exam (2000-2002) using observed PM10 from monitors nearest participants' residences and PM10 and PM2.5 imputed from a space-time model. We examined three log-transformed arterial stiffness outcome measures: Young's modulus (YM) from carotid artery ultrasound and large (C1) and small (C2) artery vessel compliance from the radial artery pulse wave. All associations are expressed per 10 μg/m3 increment in PM and were adjusted for weather, age, sex, race, glucose, triglycerides, diabetes, waist:hip ratio, seated mean arterial pressure, smoking status, pack-years, cigarettes per day, environmental tobacco smoke, and physical activity. C1 and C2 models were further adjusted for heart rate, weight, and height.

RESULTS

Long-term average particle exposure was not associated with greater arterial stiffness measured by YM, C1, or C2, and the few associations observed were not robust across metrics and adjustment schemes.

CONCLUSIONS

Long-term particle mass exposure did not appear to be associated with greater arterial stiffness in this study sample.

The effect of smoking on arterial stiffness

A systematic literature review was conducted using PubMed, Embase and the Cochrane Library to determine the effect of acute, chronic and passive smoking on arterial stiffness and to determine whether these effects are reversible after smoking cessation. A total of 39 relevant studies were identified and included. Acute smoking was found to cause an acute increase in arterial stiffness. Similarly, passive smoking increased arterial stiffness acutely and chronically. The majority of studies identified chronic smoking as a risk factor for increasing arterial stiffness. However, some studies found no statistical difference in arterial stiffness between nonsmokers and long-term smokers, although chronic smoking seems to sensitize the arterial response to acute smoking. In addition, whether arterial stiffness is reversed after smoking cessation and the timeline in which this may occur could not be determined from the identified literature. The effect of smoking discontinuation on arterial stiffness remains to be established by prospective smoking cessation trials.

Correlates of secondhand tobacco smoke exposure among persons with severe and persistent mental illness (SPMI) accessing community mental health services

To examine the correlates of secondhand tobacco smoke (SHS) exposure in a sample of individuals with severe and persistent mental illness (SPMI) accessing community mental health services. Cross-sectional data were collected from a voluntary sample of 788 individuals with SPMI. Nonsmokers were more likely to be exposed on the street or at a bus stop, in a park or public place; whereas smokers were more likely to report SHS exposure where they lived and at their friend's homes. In a multivariate model, only number of acquaintances who smoked and the number of sources of SHS exposure remained significantly associated with perceived frequency of SHS exposure when accounting for other correlates. There is a need for the enactment and enforcement of policies to curtail SHS exposure in outdoor, public, settings. Future research will be necessary to better understand the extent and impact of SHS exposure in this population.

Decreased aortic elasticity in healthy 11-year-old children exposed to tobacco smoke

OBJECTIVE

The goal was to assess the relationship between passive smoking and arterial elasticity in children.

METHODS

Healthy 11-year-old children (N = 386) from an atherosclerosis prevention trial (Special Turku Coronary Risk Factor Intervention Project for Children) were studied. Aortic and carotid elasticities were determined by using M-mode ultrasound imaging based on measurements of blood pressure and arterial diameter changes during the cardiac cycle. The aortic stiffness index, Young's elastic modulus, and distensibility and the respective indices for the carotid artery were calculated. Exposure to tobacco smoke was measured by using serum cotinine concentrations, and children were classified into 3 groups, that is, the noncotinine group (n = 220; undetectable cotinine levels), the low-cotinine group (n = 127; cotinine levels of 0.2-1.6 ng/mL), and the top-decile cotinine group (n = 39; cotinine levels of > or =1.7 ng/mL).

RESULTS

Higher cotinine concentrations were associated with increased aortic stiffness index values. An increase in aortic Young's elastic modulus and a decrease in aortic distensibility were observed across the cotinine groups. In multivariate regression models, the cotinine level remained a significant explanatory variable regarding all aortic elasticity indices. Carotid elasticity indices showed no differences across the cotinine groups.

CONCLUSIONS

Childhood exposure to tobacco smoke (verified with serum cotinine levels) decreases aortic elastic properties in healthy children.

Secondhand tobacco smoke exposure, nicotine dependence, and smoking cessation

OBJECTIVE

To explore the association among the number of sources of secondhand tobacco smoke (SHS) exposure, nicotine dependence (ND), and smoking cessation.

DESIGN

A secondary analysis of cross-sectional data. Responses for the main study were obtained in 2001 from a controlled trial of the Quit and Win Tobacco Free Contest in Kentucky.

SAMPLE

822 current smokers.

MEASUREMENTS

Demographic variables (age, gender, educational status, income, and ethnicity) the number of sources of SHS exposure, smoking frequency, length of abstinence from smoking, age of smoking initiation, smoking cessation attempts, intentions to quit smoking, and ND.

RESULTS

The number of sources of SHS exposure was associated with higher ND and smoking frequency, and related to low intentions and attempts to quit smoking. The number of sources of SHS exposure contributed to 11% of the variance in the final ND model, after accounting for control and potential mediating variables.

CONCLUSIONS

The number of sources of SHS exposure may be an important factor influencing ND and intentions and attempts to quit smoking. Further studies are needed to explore the association between SHS exposure and ND among smokers to guide treatment and policy development.

Measuring tobacco smoke exposure among smoking and nonsmoking bar and restaurant workers

PURPOSE

This study assesses the validity of hair nicotine as a biomarker for secondhand smoke (SHS) exposure. Although most biomarkers of tobacco-smoke exposure have a relatively short half-life, hair nicotine can measure several months of cumulative SHS exposure.

DESIGN

A cross-sectional study of hospitality-industry workers.

METHOD

Hair samples were obtained from 207 bar and restaurant workers and analyzed by the reversed-phase high-performance liquid chromatography with electrochemical detection (HPLC-ECD) method. Self-reported tobacco use and sources of SHS exposure were assessed.

FINDINGS

Higher hair-nicotine levels were associated with more cigarettes smoked per day among smokers and a greater number of SHS-exposure sources among nonsmokers. Number of SHS exposure sources, gender, number of cigarettes smoked per day, and type of establishment predicted hair-nicotine levels.

DISCUSSION

Hair nicotine is a valid measure of SHS exposure. It may be used as an alternative biomarker to measure longer term SHS exposure.

Environmental Tobacco Smoke Exposure and Risk of Stroke in Nonsmokers: A Review With Meta-analysis

Our objective was to provide a comprehensive review of the epidemiologic evidence relating stroke to exposure to environmental tobacco smoke (passive smoking) in lifelong nonsmokers. In all, 7 prospective, 6 case-control, and 3 cross-sectional studies were identified that provided relevant information. The 16 studies varied considerably in design, exposure indices used, and disease definition. Based on 24 sex-specific relative risk estimates, and using current spousal exposure (or nearest equivalent) as the exposure index, meta-analysis gave an overall estimate of 1.25 (95% confidence interval 1.16-1.36), with no significant heterogeneity. There was no significant heterogeneity by sex, year of publication, fatality, or disease end point. There was some indication that relative risks were less elevated in prospective studies and in US or European studies. No elevation was seen for subarachnoid hemorrhage. The estimate was similar using ever rather than current exposure, or total rather than spousal exposure. Adjustment for risk factors other than age had no material effect on the estimate. Eight studies provided dose-response estimates, the combined relative risk for the highest level of exposure being 1.56 (95% confidence interval 1.34-1.82). Many studies have evident weaknesses, and recall bias and particularly publication bias are major concerns. Currently, the association is only suggestive of a possible causal relationship. A clearer picture could be obtained using data from existing very large prospective studies that have already provided risk estimates for passive smoking and heart disease, and by conducting large, well-designed studies of incident stroke.

Transposition of Great Arteries Is Associated With Increased Carotid Artery Stiffness

Transposition of great arteries is the consequence of abnormal aorticopulmonary septation. Animal embryonic data indicate that septation and elastogenesis are related events, but human and clinical data are not available. We tested the hypothesis that large artery elastic function was impaired in patients with transposition of great arteries. We studied 34 patients aged 9 to 19 years, 12+/-3 years after atrial switch operation; 14 patients aged 7 to 9 years, 8+/-1 years after arterial switch operation; and 108 healthy control subjects matched for age. Carotid artery diastolic diameter and pulsatile distension were determined by echo wall-tracking; carotid blood pressure was measured by tonometry. Systolic pressure was higher and diastolic pressure was lower in patients than in controls. Patients with atrial and arterial switch repair were compared with their respective controls by 2-factor ANOVA. For patients with atrial switch repair versus control, stiffness index beta was 4.9+/-1.5 versus 3.1+/-1.0 (P<0.001); for patients witch arterial switch versus control, stiffness index beta was 3.8+/-1.1 versus 2.1+/-0.6 (P<0.001). Similar differences were observed for carotid compliance, distensibility, and incremental elastic modulus as well. The interaction term was not significant for any of the elastic variables, indicating that carotid stiffening was a characteristic of the condition and not the consequence of different hemodynamics. Carotid artery is markedly stiffer in patients, suggesting that impaired elastogenesis may constitute part of the congenital abnormality. Since carotid artery stiffness has been established as an independent cardiovascular risk factor, this condition may have consequences in the clinical management of these patients.

The effect of chronic tobacco smoking on arterial stiffness

AIMS

Cardiovascular disease caused by smoking is related to the pathophysiological burden placed on the vascular endothelium. We studied the effect of chronic cigarette smoking on arterial wave reflection (study 1) and smoking cessation on pulse wave analysis (study 2).

METHODS

Fifty smokers and 50 age- and sex-matched nonsmokers participated in study 1. Study 2 recruited 20 volunteers from the stop smoking clinic at the Royal Hallamshire Hospital, Sheffield, UK. Systemic augmentation index (AIx) and carotid-femoral pulse wave velocity (PWV) were measured using the SphygmoCor system. Brachial blood pressure (BP) (Omron 705-CP-E), AIx and PWV were recorded at a single visit in study 1. Study 2 measured these variables on 'quit day' and 4 weeks later.

RESULTS

In study 1, AIx was significantly higher in smokers than in nonsmokers (median 17.25 vs. 11.75%, P = 0.004). Multiple regression analysis showed a significant correlation between AIx and age, diastolic BP, smoking status (P < 0.001), blood glucose (P = 0.045) and weight (P = 0.049). In study 2, AIx significantly reduced after 4 weeks of abstinence in successful quitters (n = 10) compared with relapsed smokers (n = 4) (median 5.0 vs.- 9.5; P = 0.013). PWV did not reach significance in either study.

CONCLUSIONS

Chronic tobacco smoking is associated with endothelial dysfunction and increased AIx in subjects of a wide age range free from additional cardiovascular risk factors, which is partially reversible after 4 weeks of smoking cessation.

Cardiovascular effects of secondhand smoke: nearly as large as smoking

BACKGROUND

Secondhand smoke increases the risk of coronary heart disease by approximately 30%. This effect is larger than one would expect on the basis of the risks associated with active smoking and the relative doses of tobacco smoke delivered to smokers and nonsmokers.

METHODS AND RESULTS

We conducted a literature review of the research describing the mechanistic effects of secondhand smoke on the cardiovascular system, emphasizing research published since 1995, and compared the effects of secondhand smoke with the effects of active smoking. Evidence is rapidly accumulating that the cardiovascular system--platelet and endothelial function, arterial stiffness, atherosclerosis, oxidative stress, inflammation, heart rate variability, energy metabolism, and increased infarct size--is exquisitely sensitive to the toxins in secondhand smoke. The effects of even brief (minutes to hours) passive smoking are often nearly as large (averaging 80% to 90%) as chronic active smoking.

CONCLUSIONS

The effects of secondhand smoke are substantial and rapid, explaining the relatively large risks that have been reported in epidemiological studies.

The association between fatal coronary heart disease and ambient particulate air pollution: Are females at greater risk?

The purpose of this study was to assess the effect of long-term ambient particulate matter (PM) on risk of fatal coronary heart disease (CHD). A cohort of 3,239 nonsmoking, non-Hispanic white adults was followed for 22 years. Monthly concentrations of ambient air pollutants were obtained from monitoring stations [PM < 10 microm in aerodynamic diameter (PM10), ozone, sulfur dioxide, nitrogen dioxide] or airport visibility data [PM < 2.5 microm in aerodynamic diameter (PM2.5)] and interpolated to ZIP code centroids of work and residence locations. All participants had completed a detailed lifestyle questionnaire at baseline (1976), and follow-up information on environmental tobacco smoke and other personal sources of air pollution were available from four subsequent questionnaires from 1977 through 2000. Persons with prevalent CHD, stroke, or diabetes at baseline (1976) were excluded, and analyses were controlled for a number of potential confounders, including lifestyle. In females, the relative risk (RR) for fatal CHD with each 10-microg/m3 increase in PM2.5 was 1.42 [95% confidence interval (CI), 1.06-1.90] in the single-pollutant model and 2.00 (95% CI, 1.51-2.64) in the two-pollutant model with O3. Corresponding RRs for a 10-microg/m3 increase in PM(10-2.5) and PM10 were 1.62 and 1.45, respectively, in all females and 1.85 and 1.52 in postmenopausal females. No associations were found in males. A positive association with fatal CHD was found with all three PM fractions in females but not in males. The risk estimates were strengthened when adjusting for gaseous pollutants, especially O3, and were highest for PM2.5. These findings could have great implications for policy regulations.

Ambient air pollution and atherosclerosis in Los Angeles

Associations have been found between long-term exposure to ambient air pollution and cardiovascular morbidity and mortality. The contribution of air pollution to atherosclerosis that underlies many cardiovascular diseases has not been investigated. Animal data suggest that ambient particulate matter (PM) may contribute to atherogenesis. We used data on 798 participants from two clinical trials to investigate the association between atherosclerosis and long-term exposure to ambient PM up to 2.5 microm in aerodynamic diameter (PM2.5). Baseline data included assessment of the carotid intima-media thickness (CIMT), a measure of subclinical atherosclerosis. We geocoded subjects' residential areas to assign annual mean concentrations of ambient PM2.5. Exposure values were assigned from a PM2.5 surface derived from a geostatistical model. Individually assigned annual mean PM2.5 concentrations ranged from 5.2 to 26.9 microg/m3 (mean, 20.3). For a cross-sectional exposure contrast of 10 microg/m3 PM2.5, CIMT increased by 5.9% (95% confidence interval, 1-11%). Adjustment for age reduced the coefficients, but further adjustment for covariates indicated robust estimates in the range of 3.9-4.3% (p-values, 0.05-0.1). Among older subjects (greater than or equal to 60 years of age), women, never smokers, and those reporting lipid-lowering treatment at baseline, the associations of PM2.5 and CIMT were larger with the strongest associations in women 60 years of age (15.7%, 5.7-26.6%). These results represent the first epidemiologic evidence of an association between atherosclerosis and ambient air pollution. Given the leading role of cardiovascular disease as a cause of death and the large populations exposed to ambient PM2.5, these findings may be important and need further confirmation.

Respiratory health consequences of environmental tobacco smoke

Over the last several decades there has been a growing interest in examining the health consequences of environmental tobacco smoke (ETS). As a result of a wide body of research, ETS is now considered an unacceptable and entirely preventable public health hazard, and public policy increasingly discourages the presence of tobacco smoke in the public domain. This article provides an overview of the composition of ETS and the major diseases and disorders strongly linked to ETS, emphasizing the effects of ETS on pulmonary function, asthma, and lung cancer.

A 2-year follow-up study of cigarette smoking and risk of dementia

The report focused on investigating the relationship between cigarette smoking and dementia in elderly people through prospective studies. We did a 2-year follow-up study of elderly people. A total of 2820 participants aged 60 years old and over from six communities of Chongqing agreed to take part. Dementia was diagnosed with MMSE (Mini-Mental State Examination) and DSM-III-R (Diagnostic and Statistical Manual of Mental Disorders). Participants were classified as never smokers, past smokers, and current smokers. During follow-up, we recorded incident cases of dementia. The association of smoking and dementia was investigated using proportional hazards regression analysis. A total of 121 incident cases of dementia were detected, of which 84 (69%) were Alzheimer's disease, 17 (14%) were vascular dementia, and 21(17%) were other dementia. Compared with never smokers, current smokers had an increased risk of Alzheimer's disease (RR = 2.72; 95% CI = 1.63-5.42) and vascular dementia (RR = 1.98; 95% CI = 1.53-3.12) adjusting for age, sex, education, blood pressure, and alcohol intake. Compared with light smokers, the adjusted risk of Alzheimer's disease was significantly increased among smokers with a medium level of exposure (RR = 2.56; 95% CI = 1.65-5.52), with an even higher risk of Alzheimer's disease in the heavy smoking group (RR = 3.03; 95% CI = 1.25-4.02). Smoking was associated with the risk of dementia. This study suggests that both smoking status and amount is associated with dementia.