Secondhand smoke as an acute threat for the cardiovascular system: a change in paradigm

Parental Smoking in Childhood and Brachial Artery Flow-Mediated Dilatation in Young Adults

Objective—

Passive smoking has been associated with increased cardiovascular morbidity. The present study aimed to examine the long-term effects of childhood exposure to tobacco smoke on endothelium-dependent vasodilation in adults.

Methods and Results—

The analyses were based on 2171 participants in the population-based Cardiovascular Risk in Young Finns (N=2067) and Childhood Determinants of Adult Health (N=104) studies who had measures of conventional risk factors (lipids, blood pressure, adiposity, socioeconomic status) and self-reported parental smoking status when aged 3 to 18 years at baseline. They were re-examined 19 to 27 years later when aged 28 to 45 years. Brachial artery flow-mediated dilatation was measured at follow-up with ultrasound. In analyses adjusting for age, sex, and childhood risk factors, flow-mediated dilatation was reduced among participants who had parents that smoked in youth compared to those whose parents did not smoke (Young Finns: 9.2±0.1% (mean±SEM) versus 8.6±0.1%, P =0.001; Childhood Determinants of Adult Health: 7.4±0.6% versus 4.9±0.9%, P =0.04). These effects remained after adjustment for adult risk factors including own smoking status (Young Finns, P =0.003; Childhood Determinants of Adult Health, P =0.03).

Conclusion—

Parental smoking in youth is associated with reduced flow-mediated dilatation in young adulthood measured over 20 years later. These findings suggest that passive exposure to cigarette smoke among children might cause irreversible impairment in endothelium-dependent vasodilation.

Impact of a national smoking ban on hospital admission for acute coronary syndromes: a longitudinal study

BACKGROUND

A ban on smoking in the workplace was introduced in Ireland on March 29, 2004. As exposure to secondhand smoke has been implicated in the development of coronary disease, this might impact the incidence of acute coronary syndromes (ACS).

HYPOTHESIS

The smoking ban was associated with a decreased rate of hospital admissions for ACS.

METHODS

We analyzed data collected in a registry of all patients admitted to hospital with ACS in the southwest of Ireland, catchment population 620 525, from March 2003 until March 2007.

RESULTS

In the year following implementation of the ban, there was a significant 12% reduction in ACS admissions (177.9 vs 205.9/100,000; 95% confidence interval [CI]: 164.0-185.1, P = 0.002). This reduction was due to fewer events occurring among men (281.5 vs 233.5, P = 0.0011) and current smokers (408 vs 302 admissions, P < 0.0001). There was no change in the rate of admissions for ACS in the following year (174.3/100,000; 95% CI: 164.0-185.1, P > 0.1). However, a further 13% reduction was observed between March 2006 and March 2007 (149.2; 95% CI: 139.7-159.2). Variation in admissions with time as a continuous variable also demonstrated a reduction on implementation of the smoking ban.

CONCLUSIONS

A national ban on smoking in public places was associated with an early significant decrease in hospital admissions for ACS, suggesting a rapid effect of banning smoking in public places on ACS. A further reduction of similar magnitude 2 years after implementation of the ban is consistent with a longer-term effect that should be further examined in long-term studies.

Positive impact of the Portuguese smoking law on respiratory health of restaurant workers

The impact of smoke-free law on the respiratory and sensory symptoms among restaurant workers was evaluated. Fifty-two workers in 10 Portuguese restaurants were interviewed before and 2 years after implementation of the smoke-free law. A significant reduction in self-reported workplace environmental tobacco smoke (ETS) exposure was observed after the enforcement of the law, as well as a marked reduction in adverse respiratory and sensory symptoms such as dry, itching, irritated, or watery eyes, nasal problems, and sore or dry throat or cough, between pre- and post-ban. This study demonstrates that the smoking ban was effective in diminishing the exposure symptoms among workers and consequently in improving their respiratory health. These observations may have implications for policymakers and legislators in other countries currently considering the nature and extent of their smoke-free workplace legislation.

Methods in tobacco abuse: proteomic changes following second-hand smoke exposure

Smoking is one of the leading preventable causes of disease, disability, and death in the USA and leads to more than 400,000 preventable deaths per year. Nicotine is the major alkaloid present in tobacco smoke, and many of the negative effects of smoking are attributed to nicotine. Nicotine is not only the addictive component of tobacco smoke, but also highly associated with carcinogenesis and induces oxidative stress. Furthermore, the administration of nicotine via subcutaneous mini-osmotic pumps or by injection is an established method in preclinical studies for this area of research. Thus, preclinical research on the negative effects of tobacco smoke and tobacco addiction has focused primarily on the effects of nicotine. However, there are over 4,500 components found in tobacco smoke, many of which are highly toxic. Other components may also contribute to the addictive properties of tobacco smoke. Furthermore, the negative effects of tobacco smoke are not isolated to the smoker but can have negative effects to those exposed to the secondhand smoke (SHS) stream. SHS exposure is the third leading cause of preventable death. Approximately 38,000 deaths per year are attributed to SHS exposure in the USA. SHS exposure increases the risk of heart disease by approximately 30% and is associated with increased risk of stroke, cancer, type II diabetes, as well as pulmonary disease. Thus, methods of administering tobacco smoke in a controlled environment will further our understanding of tobacco addiction and the role tobacco smoke in other disease states. Moreover, combining smoke exposure with proteomics can lead to the discovery of biomarkers that can be potentially useful tools in screening, early diagnosis, prevention, and treatment of diseases caused by SHS.

Effects of cigarette smoke residues from textiles on fibroblasts, neurocytes and zebrafish embryos and nicotine permeation through human skin

Toxic substances from cigarette smoke can attach to carpets, curtains, clothes or other surfaces and thus may pose risks to affected persons. The phenomenon itself and the potential hazards are discussed controversially, but scientific data are rare. The objective of this study was to examine the potential of textile-bound nicotine for permeation through human skin and to assess the effects of cigarette smoke extracts from clothes on fibroblasts, neurocytes and zebrafish embryos. Tritiated nicotine from contaminated cotton textiles penetrated through adult human full-thickness skin as well as through a 3D in vitro skin model in diffusion chambers. We also observed a significant concentration-dependent cytotoxicity of textile smoke extracts on fibroblast viability and structure as well as on neurocytes. Early larval tests with zebrafish embryos were used as a valid assay for testing acute vertebrate toxicity. Zebrafish development was delayed and most of the embryos died when exposed to smoke extracts from textiles. Our data show that textiles contaminated with cigarette smoke represent a potential source of nicotine uptake and can provoke adverse health effects.

Secondhand smoke exposure and inflammatory markers in nonsmokers in the trucking industry

BACKGROUND

Few studies have directly assessed the association of secondhand smoke (SHS) with cardiovascular disease-related inflammatory markers, and the findings are inconsistent.

OBJECTIVES

We assessed the association between SHS exposure and the inflammatory markers high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and soluble intercellular adhesion molecule-1 (sICAM-1) in 199 nonsmoking U.S. trucking industry workers.

METHODS

Participants provided blood samples either by mail (blood drawn at local health care provider near home) or at the work site (blood drawn by research staff on-site) and completed a health and work history questionnaire at the time of blood draw. Exposure to SHS was measured by plasma cotinine concentrations. We used multivariate regression analyses to assess the associations between levels of cotinine and inflammatory markers.

RESULTS

The median cotinine level was 0.10 ng/mL (interquartile range, 0.04-0.23 ng/mL). The odds ratios of elevated hs-CRP (above highest CRP tertile, 1.5 mg/L) were 2.85 [95% confidence interval (CI), 1.03-7.89] for the high-cotinine group (> 0.215 ng/mL) and 2.80 (95% CI, 1.11-7.10) for the moderate-cotinine group (0.05-0.215 ng/mL), compared with the low-cotinine group (< 0.05 ng/mL), adjusting for age, sex, race, educational level, obesity, previous smoking history, job title, and medical history. Plasma cotinine levels were not associated with IL-6 or sICAM-1.

CONCLUSIONS

SHS exposure, as assessed by plasma cotinine, was positively associated with hs-CRP in this group of blue-collar workers. The strength of the association with hs-CRP depended on the cut points selected for analysis.

Benefits of smoking cessation with focus on cardiovascular and respiratory comorbidities

Smoking cessation is crucial in preventing premature morbidity, disability and mortality worldwide. The effectiveness of quitting tobacco use surpasses any other intervention to minimise the risk for chronic cardiac and respiratory conditions. The overall health benefits of smoking cessation have been recognised for decades but as tobacco legislation has been changing in recent years, new evidence particularly concerning the effect of less smoke exposure on the vascular system has emerged. Recently, much research in chronic obstructive pulmonary disease (COPD) has concerned the ongoing inflammation - also in former smokers - and disease heterogeneity, which provides new knowledge regarding current and ex-smokers with COPD. Many other cardiovascular and respiratory diseases are associated with smoking, and the course of these diseases is not always studied in the context of smoking cessation versus continued smoking. This review summarises the latest available data on health benefits of smoking cessation with focus on both common and infrequent cardiovascular and respiratory diseases.

Adolescents' support for smoke-free public settings: the roles of social norms and beliefs about exposure to secondhand smoke

PURPOSE

To assess support for smoke-free policies in public settings among adolescent smokers and nonsmokers in a pro-smoking culture.

METHODS

A total of 1,924 Greek secondary school students (mean age = 14 years, standard deviation = 1.00, 50% female) from nine schools in the urban area of Thessaloniki, Greece, participated in the study. The main outcome measures were supportiveness of smoke-free policies in public settings.

RESULTS

Smoker adolescents were less supportive of smoke-free policies, compared with nonsmokers. Regression analysis showed that policy support was predicted by smoking status and motivation to smoke, social norms, and beliefs about the effects of smoking and exposure to secondhand smoke. A significant interaction between smoking status and social norms was also observed, as smoker adolescents who often encountered others smoking in public places reported less support for smoke-free public settings.

CONCLUSIONS

Three important processes underlying adolescents' support for smoke-free policies not mentioned in previous research were identified. First, social norms of the immediate social environment play a pivotal role in shaping policy support of young people. Second, the effects of smoking status on policy support are significantly moderated by exposure to public smoking. Finally, beliefs about the effects of exposure to secondhand smoke significantly predict young people's support for smoke-free public settings.

Is acute high-dose secondhand smoke exposure always harmful to microvascular function in healthy adults?

Prev Cardiol. Long-term exposure to secondhand smoke (SHS) is associated with impaired vascular function. The authors investigated the vascular and blood pressure (BP) reactions to acute SHS exposure. Twenty-five healthy nonsmoking adults underwent a 1-hour exposure to SHS (mean fine particulate matter < 2.5 μm level = 315 ± 116 μg/m(3) ). Microvascular endothelial-dependent vasodilatation (EDV) (EndoPAT, Itamar Medical, Caesarea, Israel) and aortic hemodynamics/compliance (SphygmoCor, AtCor Medical, West Ryde, Australia) were measured before and after the SHS exposure with BP measured every 15 minutes during and for a 24-hour period before and after the exposure. SHS exposure did not change EDV, aortic hemodynamics, arterial compliance, or 24-hour BP. However, diastolic BP significantly increased during the SHS exposure period by 3.4 ± 5.6 mm Hg. Our brief SHS exposure did not impair microvascular endothelial function or arterial compliance in healthy nonsmoking adults, but brachial diastolic BP increased.

Effect of secondhand smoke on occupancy of nicotinic acetylcholine receptors in brain

CONTEXT

Despite progress in tobacco control, secondhand smoke (SHS) exposure remains prevalent worldwide and is implicated in the initiation and maintenance of cigarette smoking.

OBJECTIVE

To determine whether moderate SHS exposure results in brain α(4)β(2)* nicotinic acetylcholine receptor (nAChR) occupancy.

DESIGN, SETTING, AND PARTICIPANTS

Positron emission tomography scanning and the radiotracer 2-[18F]fluoro-3-(2(S)azetidinylmethoxy) pyridine (also known as 2-[(18)F]fluoro-A-85380, or 2-FA) were used to determine α(4)β(2)* nAChR occupancy from SHS exposure in 24 young adult participants (11 moderately dependent cigarette smokers and 13 nonsmokers). Participants underwent two bolus-plus-continuous-infusion 2-FA positron emission tomography scanning sessions during which they sat in the passenger's seat of a car for 1 hour and either were exposed to moderate SHS or had no SHS exposure. The study took place at an academic positron emission tomography center. Main Outcome Measure  Changes induced by SHS in 2-FA specific binding volume of distribution as a measure of α(4)β(2)* nAChR occupancy.

RESULTS

An overall multivariate analysis of variance using specific binding volume of distribution values revealed a significant main effect of condition (SHS vs control) (F(1,22) = 42.5, P < .001) but no between-group (smoker vs nonsmoker) effect. Exposure to SHS led to a mean 19% occupancy of brain α(4)β(2)* nAChRs (1-sample t test, 2-tailed, P < .001). Smokers had both a mean 23% increase in craving with SHS exposure and a correlation between thalamic α(4)β(2)* nAChR occupancy and craving alleviation with subsequent cigarette smoking (Spearman ρ = -0.74, P = .01).

CONCLUSIONS

Nicotine from SHS exposure results in substantial brain α(4)β(2)* nAChR occupancy in smokers and nonsmokers. Study findings suggest that such exposure delivers a priming dose of nicotine to the brain that contributes to continued cigarette use in smokers. This study has implications for both biological research into the link between SHS exposure and cigarette use and public policy regarding the need to limit SHS exposure in cars and other enclosed spaces.

Non-nutrient causes of low-grade, systemic inflammation: support for a 'canary in the mineshaft' view of obesity in chronic disease

A form of low-grade, systemic inflammation ('metaflammation') is linked to many types of chronic disease. Initially, this was thought to be causally related to weight gain and obesity and a possible explanation of the link between obesity and disease. However, several lifestyle-related inducers of such inflammation, some of which are associated with obesity, but some of which are not, have now been identified. The most common of these have been nutritive related, suggesting that there could still be a relationship, either directly or indirectly, with obesity. Here we provide evidence for non-nutritive inflammatory inducers, providing further support for an earlier suggestion that while obesity, beyond a point, may have a direct link with disease, this may be neither necessary nor sufficient to explain the current epidemic of chronic disease. A more ubiquitous cause encompassing all inflammatory inducers is the modern, post-industrial environment and lifestyles emanating from this. Obesity may thus be more of 'a canary in the mineshaft', warning of bigger global problems, than just a single pathway to modern environmentally driven disease.

Cigarette smoke extracts promote vascular smooth muscle cell proliferation and enhances contractile responses in the vasculature and airway

Cigarette smoke exposure is a strong risk factor for cardiovascular and respiratory diseases. However, the knowledge about how cigarette smoke induces damage to vasculature and airway is limited. The present study was designed to examine the effects of cigarette smoke particles extracted by heptane (heptane-soluble smoke particles, HSP), by water (water-soluble smoke particles, WSP) and by DMSO (DMSO-soluble smoke particles, DSP), which represent lipophilic, hydrophilic and ambiphoteric constituents from the cigarette smoke, respectively. Human aortic smooth muscle cell (HASMC) proliferation was assessed in cell culture. Rat resistance artery and airway contractile responses to serotonin, U46619, phenylephrine, noradrenaline, acetylcholine, des-Arg⁹-bradykinin, bradykinin, sarafotoxin 6c and endothelin-1 were monitored by a sensitive myograph system. Immunocytochemistry and cell-based phosphoELISA assay were used to demonstrate activation of extracellular signal-regulated kinases 1/2 (ERK1/2). For the first time, our results demonstrate that although all the three extracts promote HASMC proliferation, the HSP and DSP effects occur earlier. HSP and DSP, but not WSP, increase the contractile responses to sarafotoxin 6c, U46619 or bradykinin in rat mesenteric artery and/or in bronchi. ERK1/2 is activated by HSP and DSP in HASMCs and inhibition of ERK1/2 abrogated the smoke extracts-induced HASMC proliferation, while blockage of nicotinic receptors had no effects, suggesting that the toxic effects of the smoke extracts occur via activation of intracellular ERK1/2 signalling, but not nicotinic receptors.

Effect of smoking cessation on the number and adhesive properties of early outgrowth endothelial progenitor cells

BACKGROUND

Endothelial progenitor cells participate in angiogenesis and vascular repair, and cardiovascular risk factors may reduce their numbers or impair their functional properties. Cigarette smoking is a leading cause of preventable cardiovascular death, however, the functional properties of these cells before and after discontinuation of tobacco use have not been systematically analyzed.

METHODS

We examined changes in the number and function of early outgrowth endothelial progenitor cells (EPC), isolated from individuals (n=144; mean age, 47.8 ± 12.0 years; 43% males; more than 50% with additional cardiovascular risk factors or disease) who successfully completed a 5-week smoking cessation (SC) programme.

RESULTS

SC significantly reduced total white blood cell count (WBC; P<0.0001), plasma LDL cholesterol (P=0.0002) and fibrinogen (P<0.0001) levels, but did not alter the number of circulating CD34(+), VEGFR2(+) or CD34(+), CD133(+) cells (P=0.14 and 0.57, respectively). Fewer acLDL(+), lectin(+) cells could be expanded from peripheral blood mononuclear cells in comparison to baseline (P<0.001). Furthermore, SC was associated with reduced EPC adhesion to fibronectin (P<0.001) or TNFα-activated endothelial cells (P=0.003), and a diminished incorporation of EPC into endothelial cell networks (P=0.035). Mechanistically, significantly reduced β1- and β2-integrin expression (P<0.001 and 0.007) and lower contents of intracellular reactive oxygen species (P<0.007) were detected in EPC following SC, in addition to reduced plasma asymmetric dimethyl-L-arginine (ADMA) levels (P=0.0003).

CONCLUSIONS

Our findings suggest that the oxidative and inflammatory stress reduction associated with smoking cessation impair the adhesiveness of monocyte-derived EPC.

Passive smoking and the development of cardiovascular disease in children: a systematic review

Passive smoking may be implicated in the development of cardiovascular disease (CVD) in children because of their partially developed physiological systems. The aim of the present systematic paper is to investigate whether passive smoking is associated with factors that influence the development of CVD in children. Data sources included Medline, Cochrane Library, Cumulative Index to Nursing & Allied Health (CINAHL) research database, Google Scholar, Excerpta Medica database (EMBASE), the 2006 Office of the Surgeon General's report, and the 2005 report from the California Environmental Protection Agency. We identified a total of 42 relevant articles (i.e., 30 reviews and 12 observational). Results revealed that passive smoking may be implicated in deteriorating cardiovascular status in children in terms of unfavorable high-density lipoprotein levels and deteriorated vascular function.

Time trends in cardiovascular disease mortality in Russia and Germany from 1980 to 2007 - are there migration effects?

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of death in the industrialized world. Large variations in CVD mortality between countries and also between population subgroups within countries have been observed. Previous studies showed significantly lower risks in German repatriates and Jews emigrating from Russia than in the general Russian population. We examined to what degree the migration of large subgroups influenced national CVD mortality rates.

METHODS

We used WHO data to map the CVD mortality distribution in Europe in 2005. Supplemented by data of the Statistisches Bundesamt, the mortality trends in three major CVD groups between 1980 and 2007 in Russia and Germany are displayed, as well as demographic information. The effects of migration on demography were estimated and percentage changes in CVD mortality trends were calculated under the assumption that migration had not occurred.

RESULTS

Cardiovascular disease mortality patterns within Europe showed a strong west-east gradient with ratios up to sixfold. In Germany, the CVD mortality levels were low and steadily decreasing, whereas in Russia they fluctuated at high levels with substantial differences between the sexes and strong correlations with political changes and health campaigns. The trends in both Russia and Germany were affected by the migration that occurred in both countries over recent decades. However, our restricted focus in only adjusting for the migration of German repatriates and Jews had moderate effects on the national CVD mortality statistics in Germany (+1.0%) and Russia (-0.6%).

CONCLUSIONS

The effects on CVD mortality rates due to migration in Germany and Russia were smaller than those due to secular economical changes. However, migration should still be considered as a factor influencing national mortality trends.