Effect of passive smoking on angina pectoris

Exposure to indoor air pollution and angina among aging adults in India: evidence from a large-scale nationwide study

This study tried to understand the association between exposure to indoor air pollution and angina among the aging population in India. We utilized the data from the Longitudinal Ageing Study in India (LASI) Wave-1 (2017-2018), with a sample of 62,846 aging adults. We applied Chi-square and multivariate logistic regression models. The odds of angina were higher among individuals living in households that used solid fuels for cooking (aOR = 1.15, 99% CI- 1.09-1.20), had someone smoked inside the house (aOR = 1.12, 99% CI- 1.07-1.18), and households that used of incenses inside the home (aOR = 1.11, 99% CI- 1.05-1.18). In addition, it was also found that work-limiting impairment, unhealthy behaviors, and poor health status increased the odds of angina. These results indicate the need to reduce in-house air pollution by promoting clean fuel usage and changing attitudes and practices. Other implications are discussed.

Angina Outcomes in Nonsmokers Exposed to Secondhand Smoke: Results from the National Health and Nutrition Examination Survey 2007–2018

Objective  The aim of the study is to examine the relationship between secondhand smoke (SHS) and angina using the National Health and Nutrition Examination Survey database over a 12-year period.

Methods  Self-reported smoking status and cotinine levels were used to identify exposure groups (smokers, nonsmokers, and secondhand smokers), and medical history of angina was also collected via a self-report survey. The association between exposure to SHS and angina was analyzed using odd ratios with 95% confidence intervals calculated using two logistic regression models.

Results  The study found that when aggregating data from all 12 years, secondhand smokers are 42.9% significantly more likely to report having experienced angina, while smokers were 97.7% significantly more likely to report having angina compared with nonsmokers.

Conclusions  This study is the first of its kind to examine data from a national database over a 12-year period to determine an association between SHS and angina outcomes, thus highlighting the importance of reducing SHS exposure to improve cardiovascular health.

Smoking, alcohol and opioids effect on coronary microcirculation: an update overview

Smoking, heavy alcohol drinking and drug abuse are detrimental lifestyle factors leading to loss of million years of healthy life annually. One of the major health complications caused by these substances is the development of cardiovascular diseases (CVD), which accounts for a significant proportion of substance-induced death. Smoking and excessive alcohol consumption are related to the higher risk of acute myocardial infarction. Similarly, opioid addiction, as one of the most commonly used substances worldwide, is associated with cardiac events such as ischemia and myocardial infarction (MI). As supported by many studies, coronary artery disease (CAD) is considered as a major cause for substance-induced cardiac events. Nonetheless, over the last three decades, a growing body of evidence indicates that a significant proportion of substance-induced cardiac ischemia or MI cases, do not manifest any signs of CAD. In the absence of CAD, the coronary microvascular dysfunction is believed to be the main underlying reason for CVD. To date, comprehensive literature reviews have been published on the clinicopathology of CAD caused by smoking and opioids, as well as macrovascular pathological features of the alcoholic cardiomyopathy. However, to the best of our knowledge there is no review article about the impact of these substances on the coronary microvascular network. Therefore, the present review will focus on the current understanding of the pathophysiological alterations in the coronary microcirculation triggered by smoking, alcohol and opioids.

Using the Law to Protect Health: The Frustrating Case of Smoking

It is Recommended … That it be recognized by all organizations and associations concerned with smoking and health that the campaign against smoking is political and economic in character and requires decisions based on political and economic factors.

The only way we know today to stop cancer is to stop smoking. …

Household Air Pollution and Angina Pectoris in Low- and Middle-Income Countries: Cross-Sectional Evidence from the World Health Survey 2002-2003

The evidence regarding the effects of household air pollution on angina pectoris is limited in low-and middle-income countries (LMICs). We sought to examine the association between household air pollution and angina pectoris across several countries. We analyzed data of individuals from 46 selected countries participating in the cross-sectional World Health Survey (WHS) 2002–2003. Pooled and stratified (sex, continent) logistic regression with sampling weights was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) to quantify associations between the use of different household fuels with angina pectoris. In the pooled sample, we observed lower odds of angina pectoris with electricity use (OR: 0.68, 95% CI: 0.56–0.83) compared to those households reporting the use of gas as a household fuel. Increased odds of angina pectoris were observed with the use of agriculture/dung/shrub/other (OR: 1.65, 95% CI: 1.30–2.09), mixed (solid and non-solid fuels) (OR: 1.31, 95% CI: 1.09–1.56), and mixed solid fuel use (OR: 1.59, 95% CI: 1.12–2.25). Higher odds of angina pectoris were observed mainly with solid fuel use. The results highlight the importance of addressing these issues, especially in regions with a high proportion of solid fuel users and increasing levels of cardiovascular disease.

Effects of passive smoking and its duration on the prevalence of prediabetes and type 2 diabetes mellitus in Chinese women

Several studies have shown that active smoking is a risk factor for type 2 diabetes mellitus (T2DM). However, the effects of passive smoking on T2DM remains unknown. In this study, we investigated the effects of passive smoking and its duration on the prevalence of prediabetes and T2DM. According to passive smoking status, participants were divided into Group A (passive smokers) and Group B (controls). Furthermore, Group A was divided into three subgroups according to the duration of passive smoking: Group A1 (≤10 years), Group A2 (10–20 years), and Group A3 (>20 years). We found that the prevalence of impaired glucose tolerance (IGT) in Group A (26.6%), Group A2 (28%), and Group A3 (37.8%) was significantly higher than that in Group B (19.6%), and the prevalence gradually increased with an increase in the duration of passive smoking. Multiple logistic regression analysis showed that passive smoking for >10 years was a risk factor for impaired fasting glucose (IFG), IGT, and T2DM. Therefore, passive smoking not only increases the prevalence of IGT in a time-dependent manner, but also a risk factor for IFG, IGT, and T2DM when its duration is over 10 years.

Seasonal variation in the risk of ischemic stroke in patients with atrial fibrillation: A nationwide cohort study

BACKGROUND

Several cardiovascular diseases exhibit seasonal variations, but data about cold temperature and risk of ischemic stroke in patients with atrial fibrillation (AF) are limited.

OBJECTIVE

The purpose of this study was to investigate the risk of ischemic stroke in different seasons, testing the hypothesis that the cold weather season would increase the risk of stroke in AF.

METHODS

This study used the National Health Insurance Research Database in Taiwan. From 2000 to 2012, a total of 289,559 AF patients were enrolled, and 34,991 experienced ischemic stroke after mean follow-up of 3 years. The relationship between risk of ischemic stroke and temperatures was analyzed.

RESULTS

The highest incidence of ischemic stroke was observed in winter, which was the coldest season, with an incidence rate of 0.33 per 100 person-months. Compared with the summer period, the risk of ischemic stroke increased by 10% in spring (incidence rate ratio [IRR] 1.10; 95% confidence interval [CI] 1.07-1.13) and by 19% in winter (IRR 1.19; 95% CI 1.15-1.22) but did not differ significantly between summer and autumn (IRR 1.00; 95% CI 0.97-1.03). Compared with the days with an average temperature of 30°C, the risk of ischemic stroke for days with an average temperature <20°C significantly increased. Lower 7-, 10-, or 14-day average temperatures were significantly associated with an increased risk of ischemic stroke in the case-crossover analysis.

CONCLUSION

In this nationwide study, a seasonal variation of incidence of ischemic stroke in AF patients was observed, with an increased risk of stroke on days with an average temperature <20°C. AF-related stroke may be influenced by environmental interactions.

Secondhand smoke exposure and risk of incident peripheral arterial disease and mortality: a Scotland-wide retrospective cohort study of 4045 non-smokers with cotinine measurement

BACKGROUND

Active smoking is an important risk factor for all-cause mortality and peripheral arterial disease (PAD). In contrast, published studies on the associations with secondhand smoke (SHS) are limited. The aim of this study was to examine the associations between SHS exposure and incident PAD, as well as mortality, among middle-aged non-smokers.

METHODS

We undertook a retrospective, cohort study using record linkage of the Scottish Health Surveys between 1998 and 2010 to hospital admissions and death certificates. Inclusion was restricted to participants aged > 45 years. Cox proportional hazard models were used to examine the association between SHS exposure and incident PAD (hospital admission or death) and all-cause mortality, with adjustment for potential confounders.

RESULTS

Of the 4045 confirmed non-smokers (self-reported non-smokers with salivary cotinine concentrations < 15 ng/mL), 1163 (28.8%) had either moderate or high exposure to SHS at baseline. In men, high exposure to SHS (cotinine ≥2.7 ng/mL) was associated with increased risk of all-cause mortality (fully adjusted hazard ratio [HR] 1.54, 95% CI 1.07-2.22, p = 0.020) with evidence of a dose-relationship (p for trend = 0.004). In men, high exposure to SHS was associated with increased risk of incident PAD over the first five years of follow-up (fully adjusted HR 4.29, 95% CI 1.14-16.10, p = 0.031) but the association became non-significant over longer term follow-up.

CONCLUSIONS

SHS exposure was independently associated with all-cause mortality and may be associated with PAD, but larger studies, or meta-analyses, are required to confirm the latter.

Cardiovascular Abnormalities in Carbon Monoxide Poisoning

Acute carbon monoxide (CO) poisoning is the most common cause of poisoning and poisoning-related death in the United States. It manifests as broad spectrum of symptoms ranging from mild headache, nausea, and fatigue to dizziness, syncope, coma, seizures resulting in cardiovascular collapse, respiratory failure, and death. Cardiovascular complications of CO poisoning has been well reported and include myocardial stunning, left ventricular dysfunction, pulmonary edema, and arrhythmias. Acute myocardial ischemia has also been reported from increased thrombogenicity due to CO poisoning. Myocardial toxicity from CO exposure is associated with increased short-term and long-term mortality. Carboxyhemoglobin (COHb) levels do not correlate well with the clinical severity of CO poisoning. Supplemental oxygen remains the cornerstone of therapy for CO poisoning. Hyperbaric oxygen therapy increases CO elimination and has been used with wide variability in patients with evidence of neurological and myocardial injury from CO poisoning, but its benefit in limiting or reversing cardiac injury is unknown. We present a comprehensive review of literature on cardiovascular manifestations of CO poisoning and propose a diagnostic algorithm for managing patients with CO poisoning.

Estimating the Economic Impact of Secondhand Smoke on the Health of a Community

Purpose.

This study provides a model to estimate the health-related costs of secondhand smoke exposure at a community level.

Model Development.

Costs of secondhand smoke–related mortality and morbidity were estimated using national attributable risk values for diseases that are causally related to secondhand smoke exposure for adults and children. Estimated costs included ambulatory care costs, hospital inpatient costs, and loss of life costs based on vital statistics, hospital discharge data, and census data.

Application of the Model.

The model was used to estimate health-related costs estimates of secondhand smoke exposure for Marion County, Indiana. Attributable risk values were applied to the number of deaths and hospital discharges to determine the number of individuals impacted by secondhand smoke exposure.

Results.

The overall cost of health care and premature loss of life attributed to secondhand smoke for the study county was estimated to be $53.9 million in 2000—$10.5 million in health care costs and $20.3 million in loss of life for children compared with $6.2 million in health care costs and $16.9 million in loss of life for adults. This amounted to $62.68 per capita.

Conclusions.

This method may be replicated in other counties to provide data needed to educate the public and community leaders about the health effects and costs of secondhand smoke exposure.

Are active and passive smoking associated with cardiometabolic risk factors in adolescents? The CASPIAN-III Study

BACKGROUND

Smoking is an important risky behavior in adolescents worldwide. Active and passive smoking have adverse health effects at public and individual levels.

OBJECTIVE

This study aimed to evaluate the association of active and passive smoking with cardiometabolic risk factors in a national sample of Iranian adolescents.

METHODS

Participants consisted of 5625 students, aged 10-18 years, studied in the third survey of a national school-based surveillance system. Participants were classified into three groups based on smoking pattern: active smoker, passive smoker, and exposure to smoke (active or passive or both of them). Considering the Adult Treatment Panel III criteria modified for the paediatric age group, metabolic syndrome (MetS) was defined as the co-existence of three out of five components of abdominal obesity, elevated blood pressure, elevated fasting plasma glucose, high serum triglycerides, and depressed high-density cholesterol (HDL-C) levels.

RESULTS

The mean (SD) age of participants was 14.7 (2.4) years. Mean level of HDL-C was significantly lower in all types of smoking compared to non-smokers. Low HDL-C and MetS had significant association with active smoking (OR 2.10, 95% CI 1.33-3.31 and OR 5.24, 95% CI 2.41-11.37), passive smoking (OR 1.19, 95% CI 1.01-1.43 and OR 1.79, 95% CI 1.09-2.96), and smoking exposure (OR 1.20, 95% CI 1.01-1.43 and OR 2.02, 95% CI 1.22-3.31), respectively.

CONCLUSION

This study confirms that both smoking and exposure to smoke are associated with an increased risk of MetS and some of the cardiometabolic risk factors in adolescents. Preventive measures against passive smoking should be considered as a health priority in the paediatric age groups.

Risk of Heart Failure and Death After Prolonged Smoking Cessation: Role of Amount and Duration of Prior Smoking

BACKGROUND

According to the 2004 Surgeon General's Report on Health Consequences of Smoking, after >15 years of abstinence, the cardiovascular risk of former smokers becomes similar to that of never-smokers. Whether this health benefit of smoking cessation varies by amount and duration of prior smoking remains unclear.

METHODS AND RESULTS

Of the 4482 adults ≥65 years without prevalent heart failure (HF) in the Cardiovascular Health Study, 2556 were never-smokers, 629 current smokers, and 1297 former smokers with >15 years of cessation, of whom 312 were heavy smokers (highest quartile; ≥32 pack-years). Age-sex-race-adjusted hazard ratios (aHR) and 95% confidence intervals (CI) for centrally adjudicated incident HF and mortality during 13 years of follow-up were estimated using Cox regression models. Compared with never-smokers, former smokers as a group had similar risk for incident HF (aHR, 0.99; 95% CI, 0.85-1.16) and all-cause mortality (aHR, 1.08; 95% CI, 0.96-1.20), but former heavy smokers had higher risk for both HF (aHR, 1.45; 95% CI, 1.15-1.83) and mortality (aHR, 1.38; 95% CI, 1.17-1.64). However, when compared with current smokers, former heavy smokers had lower risk of death (aHR, 0.64; 95% CI, 0.53-0.77), but not of HF (aHR, 0.97; 95% CI, 0.74-1.28).

CONCLUSIONS

After >15 years of smoking cessation, the risk of HF and death for most former smokers becomes similar to that of never-smokers. Although this benefit of smoking cessation is not extended to those with ≥32 pack-years of prior smoking, they have lower risk of death relative to current smokers.

Smoking ban in public areas is associated with a reduced incidence of hospital admissions due to ST-elevation myocardial infarctions in non-smokers. Results from the Bremen STEMI Registry

INTRODUCTION

Laws banning tobacco smoking from public areas have been passed in several countries, including the region of Bremen, Germany at the end of 2007. The present study analyses the incidence of hospital admissions due to ST-elevation myocardial infarctions (STEMIs) before and after such a smoking ban was implemented, focusing on differences between smokers and non-smokers. In this respect, data of the Bremen STEMI Registry (BSR) give a complete epidemiological overview of a region in northwest Germany with approximately 800,000 inhabitants since all STEMIs are admitted to one central heart centre.

METHODS AND RESULTS

Between January 2006 and December 2010, data from the BSR was analysed focusing on date of admission, age, gender, and prior nicotine consumption. A total of 3545 patients with STEMI were admitted in the Bremen Heart Centre during this time period. Comparing 2006-2007 vs. 2008-2010, hence before and after the smoking ban, a 16% decrease of the number of STEMIs was observed: from a mean of 65 STEMI/month in 2006-2007 to 55/month in 2008-2010 (p < 0.01). The group of smokers showed a constant number of STEMIs: 25/month in 2006-2007 to 26/month in 2008-2010 (+4%, p = 0.8). However, in non-smokers, a significant reduction of STEMIs over time was found: 39/month in 2006-2007 to 29/month in 2008-2010 (-26%, p < 0.01). The decline of STEMIs in non-smokers was consistently observed in all age groups and both sexes. Adjusting for potentially confounding factors like hypertension, obesity, and diabetes mellitus did not explain the observed decline.

CONCLUSIONS

In the BSR, a significant decline of hospital admissions due to STEMIs in non-smokers was observed after the smoking ban in public areas came into force. No reduction of STEMI-related admissions was found in smokers. These results may be explained by the protection of non-smokers from passive smoking and the absence of such an effect in smokers by the dominant effect of active smoking.

Second-hand tobacco smoke and cardiovascular disease risk: an epidemiological review

In this review, we have sought to examine the epidemiological, basic science, and public health data regarding the association between second-hand smoke (SHS) exposure and the development of coronary heart disease (CHD). SHS increases the risk of CHD by 25-30% according to multiple cohort, case-control, and meta-analytical studies. Physiologic and basic science research suggest that the mechanisms by which SHS affects the cardiovascular system are multiple and include increased thrombogenesis and low-density lipoprotein oxidation, decreased exercise tolerance, dysfunctional flow-mediated vasodilatation, and activation of inflammatory pathways with concomitant oxidative damage and impaired vascular repair. As a result, chronic exposure promotes atherogenesis and the development of cardiovascular disease, increasing the risk of having an acute coronary syndrome (ACS). With the implementation of statewide and nationwide public smoke-free legislation across the United States and Europe, respectively, over the last 10-15 years, there has been a significant and reciprocal decline in the incidence of emergency admissions for ACS by an average 17% despite persistent attempts on the part of the tobacco industry to diminish the correlation between SHS exposure and CHD. These findings underscore the importance of the effects of smoking legislation on community health.

Association between smoking and outcomes in older adults with atrial fibrillation

Tobacco smoking is a risk factor for atrial fibrillation (AF), but little is known about the impact of smoking in patients with AF. Of the 4060 patients with recurrent AF in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial, 496 (12%) reported having smoked during the past two years. Propensity scores for smoking were estimated for each of the 4060 patients using a multivariable logistic regression model and were used to assemble a matched cohort of 487 pairs of smokers and nonsmokers, who were balanced on 46 baseline characteristics. Cox and logistic regression models were used to estimate the associations of smoking with all-cause mortality and all-cause hospitalization, respectively, during over 5 years of follow-up. Matched participants had a mean age of 70 ± 9 years (± S.D.), 39% were women, and 11% were non-white. All-cause mortality occurred in 21% and 16% of matched smokers and nonsmokers, respectively (when smokers were compared with nonsmokers, hazard ratio=HR=1.35; 95% confidence interval=95%CI=1.01-1.81; p=0.046). Unadjusted, multivariable-adjusted and propensity-adjusted HR (95% CI) for all-cause mortality associated with smoking in the pre-match cohort were: 1.40 (1.13-1.72; p=0.002), 1.45 (1.16-1.81; p=0.001), and 1.39 (1.12-1.74; p=0.003), respectively. Smoking had no association with all-cause hospitalization (when smokers were compared with nonsmokers, odds ratio=OR=1.21; 95%CI=0.94-1.57, p=0.146). Among patients with AF, a recent history of smoking was associated with an increased risk of all-cause mortality, but had no association with all-cause hospitalization.

How and why chemicals from tobacco smoke can induce a rise in blood pressure

The primary objective of this article is to analyze the role of tobacco smoke compounds able to damage the cardiovascular system and, in particular, to interfere with blood pressure. They are products of tobacco plant leaves, like nicotine, thiocyanate and aromatic amines, and a chemical derived from cigarette combustion, carbon monoxide. Of the other thousands of chemicals, there is no clear evidence of cardiovascular damage. Nicotine and its major metabolite, cotinine, usually increase blood pressure by a direct action and an action stimulating neuro-humoral metabolites of the body as well as sympathetic stimulation. An indirect mechanism of damage exerted by elevated carboxyhemoglobin concentrations is mediated by carbon monoxide, which, mainly induces arterial wall damage and, consequently, late rising in blood pressure by a toxic direct action on endothelial and blood cells. Thiocyanate, in turn, reinforces the hypoxic effects determined by carbon monoxide. Aromatic amines, depending on their chemical structure, may exert toxic effects on the cardiovascular system although they have little effect on blood pressure. A rise in blood pressure determined by smoking compounds is a consequence of both their direct toxicity and the characteristics of their chemical chains that are strongly reactive with a large number of molecules for their spatial shape. In addition, a rise in blood pressure has been documented in individuals smoking a cigarette, acutely and chronically, with irreversible artery wall alterations several years after beginning smoking. Since cigarette smoking has a worldwide diffusion, the evidence of this topic meets the interest of both the scientific community and those individuals aiming to control smoking.

Does Smoking Act as a Friend or Enemy of Blood Pressure? Let Release Pandora's Box

In spite of the great number of observations which show the certainty of cardiovascular damage from smoking, the opinions on that are not yet unanimous. There is a discrepancy that could be attributed to the lack of reproducible data particularly in some epidemiological studies. On the contrary, experimental findings conducted on both animals and humans give evidence of exactly reproducible results of cardiovascular alterations and among these the course of Blood Pressure (BP). Findings identify an increase in BP of active smokers or non-smokers exposed to passive smoking, while a lot of others refer a lowering of BP due to smoking. This discrepancy could be explained as follows. Initially, a vasoconstriction mediated by nicotine causes acute but transient increase in systolic BP. This phase is followed by a decrease in BP as a consequence of depressant effects played chronically by nicotine itself. Simultaneously, carbon monoxide is acting directly on the arterial wall causing, in the long run, structurally irreversible alterations. At this time, there is a change in BP that increases again, and often constantly, its levels following chronic exposure. Changes in response to antihypertensive drugs have been observed in hypertensive smokers since smoking influences metabolic steps of the drugs.

Biological evidence for the acute health effects of secondhand smoke exposure

A vast number of studies on the unfavorable effects of secondhand smoke (SHS) exist within the international literature, the majority of which evaluate longitudinal epidemiological data. Although limited, the experimental studies that assess the acute and short-term effects of exposure to SHS are also increasing in number. They include cellular, animal, and human studies that indicate a number of pathophysiological mechanisms through which the deleterious effects of SHS may arise. This current review evaluates the existing biological evidence regarding the acute health effects of SHS exposure. Analyses on the inhaled toxicants and the carcinogenicity of SHS are included as well as in-depth discussions on the evidence for acute SHS-induced respiratory, cardiovascular, metabolic, endocrine and immune effects, and SHS-induced influences on oxygen delivery and exercise. The influence of the length of exposure and the duration of the observed effects is also described. Moreover, recent findings regarding the underlying pathophysiological mechanisms related to SHS are depicted so as to generate models that describe the SHS-induced effects on different systems within the human body. Based on the presented biological evidence, it is concluded that brief, acute, transient exposures to SHS may cause significant adverse effects on several systems of the human body and represent a significant and acute health hazard. Future research directions in this area include research on the concentrations of tobacco smoke constituents in the alveolar milieu following SHS exposure, individual susceptibility to SHS, as well as the effects of SHS on neurobehavioral activity, brain cell development, synaptic development, and function.

Eye and heart at mortal war: coronaries and controversy in a smoke-free Scotland

Evaluation of: Pell JP, Haw S, Cobbe S et al. Smoke-free legislation and hospitalizations for acute coronary syndrome. N. Engl. J. Med. 359, 482-491 (2008). A study is published in one of the world's most reputable medical journals and is rated a "must read" by the prestigious Faculty of 1000 [101] , yet described in the BBC News Magazine--even before it is published--as looking like "over-hasty, over confident research" [102] and ranked among "the worst junk stats" of the year by a Pro Vice Chancellor of Oxford University. Amid scenes reminiscent of the AIDS conferences of the 1980s, researchers on their way to hear the initial presentation were forced to cross a line of angry pickets waving "Junk Science" placards. The issue is controversial enough to provoke the 'First World Congress on Smoking Bans and Lies' in January 2009, and it is precisely the rapidly growing weight of evidence, rather than the lack of it, that has made it a battleground in an emerging clash between the public health community and those who deny that secondhand smoke kills.

Forty years of secondhand smoke research: the gap between discovery and delivery

CONTEXT

Public health initiatives often focus on the discovery of risk factors associated with disease and death. Although this is an important step in protecting public health, recently the field has recognized that it is critical to move along the continuum from discovery of risk factors to delivery of interventions, and to improve the quality and speed of translating scientific discoveries into practice.

EVIDENCE ACQUISITION

To understand how public health problems move from discovery to delivery, citation network analysis was used to examine 1877 articles on secondhand smoke (SHS) published between 1965 and 2005. Data were collected and analyzed in 2006-2007.

EVIDENCE SYNTHESIS

Citation patterns showed discovery and delivery to be distinct areas of SHS research. There was little cross-citation between discovery and delivery research, including only nine citation connections between the main paths. A discovery article was 83.5% less likely to cite a delivery article than to cite another discovery article (OR=0.165 [95% CI=0.139, 0.197]), and a delivery article was 64.3% less likely (OR=0.357 [95% CI=0.330, 0.386]) to cite a discovery article than to cite another delivery article. Research summaries, such as Surgeon General reports, were cited frequently and appear to bridge the discovery-delivery gap.

CONCLUSIONS

There was a lack of cross-citation between discovery and delivery, even though they share the goal of understanding and reducing the impact of SHS. Reliance on research summaries, although they provide an important bridge between discovery and delivery, may slow the development of a field.

Cardiovascular benefits of smoking regulations: The effect of decreased exposure to passive smoking

OBJECTIVES

Decreases in population rates of acute myocardial infarction (AMI) have been repeatedly seen in the first months after the introduction of regulations banning smoking in public places. By decreasing the exposure to passive smoking and its acute cardiovascular effects, smoking regulations may cause an immediate drop in AMI incidence, beginning from the initial days after their introduction. Using simulations, we quantified this expected decrease.

METHODS

Expected AMI decreases were estimated using several parameters, including prevalence of exposure to passive and active smoking, relative risks of AMI associated with active and passive smoking, decrease in exposure to passive smoking after the introduction of the regulation, and level of susceptibility of active smokers to exposure to passive smoking.

RESULTS

After evaluating several possible combinations of these parameters, we found that AMI reductions of 5-15% seem likely. For example, a scenario with a population average of 5 hours per week of overall exposure to passive smoking, a 50% reduction in this exposure after the introduction of the regulation, an acute relative risk (RR) of AMI of 4.5 in the first hour after passive smoking exposure, and similar susceptibility to passive smoking among both active and passive smokers translates into a 8.6% decrease in AMI.

CONCLUSIONS

Smoking regulations can cause immediate and relevant decreases in AMI through the prevention of exposure to passive smoking.

Is the tobacco control movement misrepresenting the acute cardiovascular health effects of secondhand smoke exposure? An analysis of the scientific evidence and commentary on the implications for tobacco control and public health practice

While chronic exposure to secondhand smoke has been well recognized as a cause of heart disease in nonsmokers, there has been recent speculation about the potential acute cardiovascular effects of transient exposure to secondhand smoke among nonsmokers; in particular, the possibility that such exposure could increase the risk of acute myocardial infarction even in an otherwise healthy nonsmoker. This paper reviews the claims being made by a number of anti-smoking and public health groups regarding the acute cardiovascular effects of secondhand smoke exposure among otherwise healthy adults, analyzes the validity of these claims based on a review of the scientific evidence, and discusses the implications of the findings for tobacco control and public health practice. Based on the analysis, it appears that a large number of anti-smoking organizations are making inaccurate claims that a single, acute, transient exposure to secondhand smoke can cause severe and even fatal cardiovascular events in healthy nonsmokers. The dissemination of inaccurate information by anti-smoking groups to the public in support of smoking bans is unfortunate because it may harm the tobacco control movement by undermining its credibility, reputation, and effectiveness. Disseminating inaccurate information also represents a violation of basic ethical principles that are a core value of public health practice that cannot and should not be sacrificed, even for a noble end such as protecting nonsmokers from secondhand smoke exposure. How the tobacco control movement responds to this crisis of credibility will go a long way towards determining the future effectiveness of the movement and its ability to continue to save lives and protect the public's health.

Smoking rates and the state of smoking interventions for children and adolescents with chronic illness

Engaging in smoking is particularly risky for children and adolescents with chronic illness whose health status is already compromised because of disease- and treatment-related complications. Yet, some of these youngsters smoke at rates at least comparable to those of their healthy peers. To date, few randomized smoking-prevention and cessation trials have been conducted in children with chronic medical problems. In this review we report on the smoking rates among youngsters with chronic illness, identify specific disease- and treatment-related complications that can be exacerbated by smoking, examine risk factors associated with tobacco use among medically compromised youngsters, and review smoking interventions that have been conducted to date with pediatric populations in the health care setting. The following chronic illnesses are included in this review: asthma, cystic fibrosis, cancer, sickle cell disease, juvenile-onset diabetes, and juvenile rheumatoid arthritis. Objectives for a tobacco-control agenda and recommendations for future tobacco studies in chronically ill pediatric populations are provided. Finally, tobacco counseling strategies are suggested for clinicians who treat these youngsters in their practices.

Cardiovascular Sequelae of Tobacco Smoking

Smoking is a known risk factor for cardiovascular disease and has been implicated in sudden cardiac death. Hypertension, hypercholesterolemia, physical inactivity, and smoking are the leading contributors to poor cardiovascular health. This article reviews the cardiovascular pathology inherent with smoking and provide insight to help develop an appropriate plan of care.

Environmental tobacco smoke: association with cardiovascular function at rest and during stress

Chronic exposure to environmental tobacco smoke (ETS) contributes to cardiovascular disease morbidity and mortality, and ETS alters cardiovascular performance during exercise stress. However, no study has examined whether those with ETS exposure have altered cardiovascular functioning during psychological stress, relative to those with no substantial ETS exposure. Seventy-eight healthy, nonsmoking adult men with either high levels of current ETS exposure at home and work or no current or significant lifetime ETS exposure were tested in a stress reactivity protocol. Blood pressure and heart rate were monitored during rest and during two psychological stressors. Those with high ETS exposure had significantly elevated heart rate and blood pressure at baseline, relative to those with no exposure. The groups did not differ on their cardiovascular stress responses. These data suggest that chronic ETS exposure is associated with altered cardiovascular functioning at rest, but not during stress. Results are discussed with regard to the role of ETS on the development of heart disease among nonsmokers.

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

The evidence that active smoking is a risk factor for cardiovascular disease (CVD) and the leading cause of preventable death is overwhelming. However, numerous epidemiological findings indicate that even passive exposure to cigarette smoke may exert detrimental effects on vascular homoeostasis. Recent experimental data provide a deeper insight into the pathophysiological mechanisms linking secondhand smoke (SHS) to CVD. Importantly, most of these effects appear to be characterized by a rapid onset. For example, the relatively low doses of toxins inhaled by passive smoking are sufficient to elicit acute endothelial dysfunction, and these effects may be related, at least in part, to the inactivation of nitric oxide. Moreover, passive smoking may directly impair the viability of endothelial cells and reduce the number and functional activity of circulating endothelial progenitor cells. In addition, platelets of non-smokers appear to be susceptible to pro-aggregatory changes with every passive smoke exposure. Overall, SHS induces oxidative stress and promotes vascular inflammation. Apart from vasoconstriction and thrombus formation, however, the myocardial oxygen balance is further impaired by SHS-induced adrenergic stimulation and autonomic dysfunction. These data strongly suggest that passive smoking is capable of precipitating acute manifestations of CVD (atherothrombosis) and may also have a negative impact on the outcome of patients who suffer acute coronary syndromes.

Prevalence and risk factors for angina in elderly Taiwanese

BACKGROUND

Angina is a hallmark symptom of cardiovascular disease, which has become an important public health issue in Taiwan. The purpose of this study was to examine the prevalence of angina and its risk factors in elderly Taiwanese.

METHODS

The study was based on a government-sponsored health examination performed in Tao-Yuan, North Taiwan, from April to June 2001. A total of 2060 participants aged 65 years and older were enrolled. Data were collected through a physician-conducted Rose questionnaire, a biochemical blood test, and a physical examination. Multivariate logistic regression was used to evaluate the relationship between angina and risk factors.

RESULTS

Prevalence of angina was 15.0% in this study, 15.1% in men, and 14.4% in women. Women had a significantly higher body mass index (BMI), total serum cholesterol, and triglyceride. Participants with hypertension had a 1.6-fold 95% confidence interval (CI): 1.2-2.0 increased risk of having angina, 1.4-fold (95% CI: 1.0-1.9) increased risk for men and 2.1-fold (95% CI: 1.3-3.5) for women. Diabetes mellitus was associated with a 1.8-fold (95% CI: 1.2-2.6) increase in the risk for men. Conventional cardiovascular risk factors such as BMI, cholesterol, triglyceride, and smoking were not significantly associated with angina.

CONCLUSIONS

The findings of this study suggest the need to prioritize hypertension treatment for elderly Taiwanese in both genders, and to provide adequate diabetes mellitus treatment for men, as these conditions are associated with the development of angina, a clinical indicator of cardiovascular disease.

Effects of passive smoking on blood pressure and aortic pressure waveform in healthy young adults--influence of gender

AIMS

Passive smoking impairs the elasticity of the aorta in patients with coronary heart disease. We therefore studied the effect of passive smoking on wave reflection in the aorta, a marker of arterial stiffness, in healthy subjects.

METHOD

We examined the effects of acute exposure to passive smoking on blood pressure and the aortic pressure waveform in healthy young men (n = 10) and women (n = 11), aged 26 +/- 5 years (mean +/- SEM) compared with 12 healthy controls, aged 24 +/- 2 years (six female) who were exposed to room air. The aortic pressure waveform was derived with radial applanation tonometry (SphygmoCor, AtCor Medical, version 6.2) and the augmentation index, a measure of arterial wave reflection in the aorta, calculated. Blood pressure (Omron Model HEM-705 CP, Omron Corporation, Tokyo, Japan) and augmentation index were measured at baseline, 15, 30 and 60 min after exposure to environmental tobacco smoke (carbon monoxide 25-30 p.p.m. for 60 min) or room air.

RESULTS

Passive smoking was associated with an increase in brachial (124 +/- 4-137 +/- 3 mmHg, P < 0.01) and aortic systolic blood pressure (110 +/- 3-123 +/- 4 mmHg, P < 0.01) at 60 min in the male subjects only. The augmentation index increased from -1.7 +/- 5 to 14 +/- 5 at 60 min (P < 0.001) only in the male subjects. The transit time of the pulse did not change significantly. The change in augmentation index was independent of the increase in blood pressure. Brachial and aortic diastolic blood pressure and heart rate did not change significantly in either male or female subjects. No haemodynamic changes were observed in the control group.

CONCLUSIONS

Acute exposure to passive smoking has a deleterious effect on the arterial pressure waveform in healthy young males but not in females, suggesting a possible protection of female gender from functional changes in arteries.

The miseries of passive smoking

Passive smoking is defined as an involuntary exposure to a combined but diluted cigarette sidestream smoke (SS, gas and particle phases that are evolved from the smoldering end of a cigarette while the smoker is not puffing) and the exhaled smoke from smokers. SS contains numerous cytotoxic substances such as polycyclic aromatic hydrocarbons (PAHs), aromatic amines, nitrosamines, heavy metals, poisonous gases, pesticide residues, and radioactive elements in quantities much higher than those found from the cigarette mainstream smoke (MS) which is puffed by smokers. Passive smoking is found to be the cause of death from cancers and cardiac disease. Furthermore, it damagingly involves reproductive organs, the nervous system, genetic materials, and is particularly hazardous to mother and child during pregnancy and to those with a history of asthma, chronic infections, induced or earned immune deficiency, or predisposed susceptibility.

Smoking and cardiovascular disease

Mainstream and ETS exposure are strong risk factors for cardiovascular disease in men and women. The relationships between smoking and cardiovascular disease result from multiple mechanisms that interact to contribute to atherosclerosis, vascular injury, thrombosis, and vascular dysfunction. We are only now beginning to understand how smoking contributes to the genesis and progression of cardiovascular disease. Because of the complexity of the interactions between nicotine and the components of MSS, ETS, and sidestream smoke with the vasculature, it will take a great deal of time and effort to fully unravel the mechanisms by which smoking contributes to cardiovascular disease. In addition, cardiovascular risk in female smokers is complicated by hormonal variables that may contribute to greater relative risk. It is important that health care providers, educators, and policy makers recognize the changing patterns of smoking and the impact of smoking on cardiovascular disease, and continue campaigns aimed at enhancing smoking cessation in the general population and in teens. Rigorous research is needed on the changing cultural, psychosocial, and environmental factors that influence tobacco use to improve our understanding of racial/ethnic smoking patterns, and identify strategic tobacco control opportunities. The capacity of tobacco control efforts to keep pace with patterns of tobacco use and cessation depends on timely recognition of emerging prevalence and cessation patterns and the resulting development of appropriate community-based programs to address the factors involved. Smoking trends today will determine how heavy the health burden of cardiovascular disease and others will be among communities tomorrow. Programs that aim at early intervention and reflect cultural diversity will be the cornerstone in the battle against tobacco use. Continued interest in research, educational, and prevention efforts are needed to help curb the risk of cardiovascular disease from smoking in men and women.

Passive smoking and the risk of coronary heart disease--a meta-analysis of epidemiologic studies

BACKGROUND

The effect of passive smoking on the risk of coronary heart disease is controversial. We conducted a meta-analysis of the risk of coronary heart disease associated with passive smoking among nonsmokers.

METHODS

We searched the Medline and Dissertation Abstracts Online data bases and reviewed citations in relevant articles to identify 18 epidemiologic (10 cohort and 8 case-control) studies that met prestated inclusion criteria. Information on the designs of the studies, the characteristics of the study subjects, exposure and outcome measures, control for potential confounding factors, and risk estimates was abstracted independently by three investigators using a standardized protocol.

RESULTS

Overall, nonsmokers exposed to environmental smoke had a relative risk of coronary heart disease of 1.25 (95 percent confidence interval, 1.17 to 1.32) as compared with nonsmokers not exposed to smoke. Passive smoking was consistently associated with an increased relative risk of coronary heart disease in cohort studies (relative risk, 1.21; 95 percent confidence interval, 1.14 to 1.30), in case-control studies (relative risk, 1.51; 95 percent confidence interval, 1.26 to 1.81), in men (relative risk, 1.22; 95 percent confidence interval, 1.10 to 1.35), in women (relative risk, 1.24; 95 percent confidence interval, 1.15 to 1.34), and in those exposed to smoking at home (relative risk, 1.17; 95 percent confidence interval, 1.11 to 1.24) or in the workplace (relative risk, 1.11; 95 percent confidence interval, 1.00 to 1.23). A significant dose-response relation was identified, with respective relative risks of 1.23 and 1.31 for nonsmokers who were exposed to the smoke of 1 to 19 cigarettes per day and those who were exposed to the smoke of 20 or more cigarettes per day, as compared with nonsmokers not exposed to smoke (P=0.006 for linear trend).

CONCLUSIONS

Passive smoking is associated with a small increase in the risk of coronary heart disease. Given the high prevalence of cigarette smoking, the public health consequences of passive smoking with regard to coronary heart disease may be important.

A seasonal variation in the incidence of ruptured abdominal aortic aneurysms

OBJECTIVE

To discover whether there is a seasonal variation in the incidence of rupture of abdominal aortic aneurysms.

DESIGN

Deaths per month due to rupture of abdominal aortic aneurysm were analysed retrospectively using a cosinor regression model.

SETTING

England and Wales.

SUBJECTS

19,599 patients who died from rupture of abdominal aortic aneurysm between January 1991 and December 1995 according to death certification data.

INTERVENTIONS

None.

RESULTS

A seasonal variation in the incidence of rupture of abdominal aortic aneurysm occurs, with a peak in winter (p = 0.003). The ratio of rupture of abdominal aortic aneurysm in males and females decreased from more than 12 to 1 below age 60 years to less than 5 to 1 over age 80 years.

CONCLUSIONS

There is a seasonal variation in the incidence of recorded deaths from abdominal aortic aneurysm in England and Wales, with a peak of deaths in the cold winter months. The underlying cause is unknown, but hypertension and tobacco smoking are predisposing factors to aortic aneurysm rupture. Exposure to tobacco smoke is known to be greater indoors in cold weather and there is a winter peak of blood pressure in hypertensive patients.

[Tobacco smoking and cardiovascular risk]

Cigarette smoking is firmly established as a risk factor for coronary heart disease, stroke and peripheral vascular disease, and is associated with increased cardiovascular mortality. A possible explanation for this relation is that smoking increases the development of atherosclerosis. Indeed, tobacco smoking has been associated with modified lipids levels, decreased fibrinolysis, increased fibrinogen levels and changes in endothelial and platelet functions for instance, which are themselves either known risk factors for or early features of atherosclerosis. Passive smoking, defined as the the involuntary exposure of non-smokers to tobacco combustion products in the indoor environment is now convincingly linked to heart disease mortality and morbidity. Stopping smoking works, decreasing cardiovascular mortality and morbidity within 5 years, whatever the age and sex of the previous smoker.

Effects of cigarette smoking on the angiographic evolution of coronary atherosclerosis. A Canadian Coronary Atherosclerosis Intervention Trial (CCAIT) Substudy. CCAIT Study Group

BACKGROUND

Although smoking increases both the risk of developing coronary disease and the risk of coronary events in patients with known coronary atherosclerosis, the effect of smoking on the evolution of coronary atherosclerosis as assessed by serial angiography is poorly defined.

METHODS AND RESULTS

Ninety smokers with coronary atherosclerosis shown on a recent angiogram and with fasting cholesterol levels between 220 and 300 mg/dL were enrolled in a randomized, double-blind, placebo-controlled trial of cholesterol-lowering therapy, along with 241 nonsmokers and exsmokers. Lovastatin at a mean dose of 36 mg/d lowered total and LDL cholesterol by 21 +/- 11% and 29 +/- 11%, respectively, but these levels changed by < 2% in placebo-treated patients. Coronary arteriography was repeated after 2 years in 72 smokers and their 557 lesions were measured blindly with an automated quantitative system, along with 1752 lesions in 227 nonsmokers. Coronary change score, the per-patient mean of the minimal lumen diameter changes for all qualifying lesions, worsened by 0.16 +/- 0.16 mm in smokers and by 0.07 +/- 0.15 mm in nonsmokers in the placebo group (P < .001). Lovastatin-treated smokers had less worsening (0.07 +/- 0.15 mm) than placebo-treated smokers (P = .024). One or more coronary lesions progressed in 16 of 34 lovastatin-treated smokers and in 28 of 38 placebo-treated smokers (47% versus 74%, P < .001). In the placebo group, new coronary lesions developed in 21 of 38 smokers and in 28 of 115 nonsmokers (55% versus 24%, P < .001); fewer lovastatin-treated smokers developed new lesions (15% versus 55%, P < .001).

CONCLUSIONS

Smoking accelerates coronary progression and new lesion formation as assessed by serial quantitative coronary arteriography. Lovastatin slows the progression of coronary atherosclerosis and prevents the development of new coronary lesions in smokers.

Effects of transdermal nicotine patches on ambulatory ECG monitoring findings: a double-blind study in healthy smokers

The cardiovascular effects and safety of transdermal nicotine patches were assessed in 50 healthy smokers using repeated 48 hour ambulatory electrocardiographic monitoring as a part of a smoking cessation program. Following baseline measurements, subjects were randomized to active (n = 25) or placebo (n = 25) treatment groups for a period of 2 weeks. Twenty-two patients in each group completed the trial. During the treatment period, subjects also received behavioral supportive therapy. Heart rate and blood pressure were significantly reduced relative to baseline both groups. In the active treatment group, mean values at baseline and after 2 weeks of double-blind treatments were as follows: heart rates, 74.0 and 71.3 beats/min, respectively; systolic blood pressure, 108.9 and 106.9 mmHg; and diastolic blood pressure, 69.7 and 68.2 mmHg, respectively. Values for the placebo group were as follows: heart rate, 73.2 and 69.6 beats/min; systolic blood pressure, 110.6 and 105.3 mmHg; diastolic blood pressure, 71.4 and 70.5 mmHg. The confidence intervals of the mean for the differences between the groups are as follows: heart rate, -4.0 +8.2; systolic blood pressure, -6.7, +10.1; diastolic blood pressure, -7.9, +3.9. There were no changes in the frequency of atrial or ventricular arrhythmia as documented by repeated 48 hour ambulatory ECG recordings from baseline period before stopping smoking compared with the treatment period in the active as well as in the placebo groups. No ischemic events were detected in any of the volunteers during either the baseline or treatment periods. As a measure of smoking abstinence, we assessed the level of carbon monoxide in expired air; in the active group, the mean levels fell from 14.2 to 4.4 ppm after smoking cessation and in the placebo group from 13.2 to 4.2 ppm. The mean urine cotinine level fell from 8.18 mmol/l at baseline to 5.74 mmol/l after 2 weeks of treatment in the active group and from 8.78 to 3.93 mmol/l in the placebo group. The number of cigarettes smoked per week in both treatment groups was significantly reduced: from 175.2 to 8.4 for the active group and from 136 to 8.6 for the placebo group. Eleven out of 22 subjects in each group quit smoking completely. Smoking withdrawal symptoms during the first week of treatment were more severe in the placebo group than in those on active treatment. There were no significant side effects in either the placebo or the active treatment groups. These results indicate that nicotine delivered by transdermal system is free of cardiac adverse effects in healthy volunteers.

Cigarette smoking and coronary heart disease: risks and management

Tobacco smoking is the leading preventable cause of death in the United States and an important cause of CHD. The effect of smoking on the cardiovascular system and coronary risk factors is pervasive. Unfavorable effects include acute increases in blood pressure and coronary vascular resistance, reduction in oxygen delivery, enhancement of platelet aggregation, increased fibrinogen, and depression of HDL cholesterol. Smoking cessation reduces cardiovascular morbidity and mortality rates relatively rapidly, even among individuals who stop smoking only after the age of 65 or after developing the clinical manifestations of CHD including myocardial infarction. Behavioral smoking-cessation programs and nicotine-replacement therapy each have been demonstrated to be effective for the treatment of smoking. The most effective treatment currently available is to combine the two. Nicotine-replacement therapy is safe and effective in patients with stable coronary heart disease. Although the threat or diagnosis of CHD is a powerful stimulus to spontaneous smoking cessation, many smokers continue to smoke after events such as myocardial infarction or CABG surgery. Studies have demonstrated that physician advice to stop smoking, supplemented by brief counseling by a nurse and follow-up, dramatically increases the smoking-cessation rate of patients hospitalized with myocardial infarction and is highly cost effective. In the outpatient setting, physician advice and counseling is also effective in helping smokers with or without CHD to stop smoking. This article outlines a simple protocol that has been demonstrated to be effective for counseling smokers.

Smoking and coronary artery disease

This article discusses the specific effects of smoking on the heart and coronary arteries and demonstrates how these effects increase the risk for cardiovascular morbidity and mortality. The conflicting results of various studies concerning the association of smoking and coronary heart disease in older persons are reviewed, and possible explanations for the discrepancy are given. Recent trends in smoking habits in the United States and the effects of these changing trends on cardiovascular mortality are presented. Finally, data are presented that demonstrate the effects of physician-directed cessation programs and the health benefits of smoking cessation in elderly and younger persons.

Hemodynamic and vascular effects of active and passive smoking

Epidemiologic studies suggest that active and passive exposure to tobacco smoke is an important cause of cardiovascular morbidity and mortality. Numerous clinical studies have demonstrated that cigarette smoking causes coronary vasoconstriction, an increase in coronary vascular resistance, and a decrease in coronary blood flow, despite an increase in myocardial oxygen demand. Cigarette smoking also induces diffuse or segmental coronary artery spasm. In habitual smokers, smoking one cigarette increases heart rate, blood pressure, cardiac index, and myocardial oxygen demand and impairs cardiac performance, probably through adrenergic stimulation and catecholamine release. Several experimental studies, however, show that cigarette smoke inhalation causes pulmonary vasodilation because of inhalation of NO and CO in the vapor phase of cigarette smoke. Similar to active smoking, passive smoking has the same adverse effects on the cardiovascular system, with similar changes in hemodynamics and coronary vasomotor tone, platelet activation, impairment of endothelium-dependent vasodilation, and endothelial dysfunction. The adverse cardiovascular effects of smoking can be partially abolished by alpha- and beta-blockers or by calcium entry blockers.

Unstable angina and exposure to carbon monoxide

Inhalation of small amounts of carbon monoxide diminishes the pain threshold in patients with stable angina pectoris. The aim of this study was to identify and describe patients who had been exposed unknowingly to toxic inhalations of this gas and subsequently presented to hospital with a clinical picture of unstable angina. Blood carboxyhaemoglobin levels of 104 patients referred with unstable angina to a coronary care unit were determined on admission. The likely source of carbon monoxide was identified in all patients. Three patients had definite carbon monoxide intoxication. Another five patients had evidence of minor exposure. When the three cases with carbon monoxide poisoning were excluded, the mean carboxyhaemoglobin level was 2.5% (+/- 1.3) for smokers (n = 30) and 0.6% (+/- 0.5) for non-smokers (n = 71). Use of fossil fuel combustion in an enclosed environment was responsible for the three most serious intoxications and one of the minor cases. We suggest that a number of patients admitted for coronary care with unstable angina may have significant carbon monoxide poisoning. This intoxication is often overlooked by attending physicians with the result that high concentration oxygen therapy is not administered, when it is in fact a necessary part of treatment.

Exposure to environmental tobacco smoke increases myocardial infarct size in rats

BACKGROUND

Exposure to environmental tobacco smoke (ETS) has been epidemiologically linked to death from ischemic heart disease in nonsmokers. In this study, we evaluated the influence of 3 days, 3 weeks, and 6 weeks of ETS exposure on myocardial infarct size in a rat ischemia/reperfusion model.

METHODS AND RESULTS

Sprague-Dawley rats exposed to ETS (four Marlboro cigarettes per 15 minutes, 6 hours per day, 5 days per week) for 3 days (n = 24), 3 weeks (n = 21), or 6 weeks (n = 12) and control rats (n = 24, n = 21, and n = 12, respectively) were subjected to 35 minutes of left coronary artery occlusion and 2 hours of reperfusion. Infarct size and risk area were determined by triphenyltetrazolium chloride and phthalocyanine blue staining, respectively. Air nicotine, carbon monoxide, and total particulates were measured during ETS exposure. Serum lipids, plasma carbon monoxide hemoglobin (COHb), nicotine, and cotinine concentrations were measured in additional groups (6 to 13 rats each) exposed to 3 days, 3 weeks, or 6 weeks of ETS and controls. Average air nicotine, carbon monoxide, and total particulate concentrations were 1103 micrograms/m3, 92 ppm, and 60 mg/m3 for the ETS-exposed rats. Infarct size (infarct mass/risk area x 100%) increased significantly in the ETS groups compared with the control groups in a dose-dependent manner (P = .023), with longer exposure associated with larger infarct size. Infarct size nearly doubled with 6 weeks of ETS exposure (61 +/- 5% versus 34 +/- 3% for control, mean +/- SEM). Plasma COHb, nicotine, and cotinine levels increased significantly in the ETS groups in a dose-dependent manner (all P < .001).

CONCLUSIONS

Exposure to passive smoking increases myocardial infarct size in a rat model of ischemia and reperfusion. This increase of infarct size exhibited a dose-response relation. These results are consistent with epidemiological studies demonstrating that ETS increases the risk of heart death.

Environmental tobacco smoke and cardiovascular disease. A position paper from the Council on Cardiopulmonary and Critical Care, American Heart Association

Although the number of cardiovascular deaths associated with environmental tobacco smoke cannot be predicted with absolute certainty, the available evidence indicates that environmental tobacco smoke increases the risk of heart disease. The effects of environmental tobacco smoke on cardiovascular function, platelet function, neutrophil function, and plaque formation are the probable mechanisms leading to heart disease. The risk of death due to heart disease is increased by about 30% among those exposed to environmental tobacco smoke at home and could be much higher in those exposed at the workplace, where higher levels of environmental tobacco smoke may be present. Even though considerable uncertainty is a part of any analysis on the health affects of environmental tobacco smoke because of the difficulty of conducting long-term studies and selecting sample populations, an estimated 35,000-40,000 cardiovascular disease-related deaths and 3,000-5,000 lung cancer deaths due to environmental tobacco smoke exposure have been predicted to occur each year. The AHA's Council on Cardiopulmonary and Critical Care has concluded that environmental tobacco smoke is a major preventable cause of cardiovascular disease and death. The council strongly supports efforts to eliminate all exposure of nonsmokers to environmental tobacco smoke. This requires that environmental tobacco smoke be treated as an environmental toxin, and ways to protect workers and the public from this health hazard should be developed. According to a 1989 Gallup survey commissioned by the American Lung Association, 86% of nonsmokers think that environmental tobacco smoke is harmful and 77% believe that smokers should abstain in the presence of nonsmokers.(ABSTRACT TRUNCATED AT 250 WORDS)

Passive smoking: the medical and economic issues

Since the late 1970s, the dangers associated with passive (involuntary) smoking have been widely debated. While research throughout the world has produced findings showing sidestream smoke to be harmful and possibly deadly to nonsmokers, an equal number of studies have indicated that the harms have been overstated or misclassified or that they are nonexistent. Those debates have culminated in a report sponsored by the Environmental Protection Agency and other federal agencies. The report concludes that second-hand cigarette smoke kills 53,000 nonsmokers a year and is a major cause of indoor air pollution. This article identifies the major medical and economic issues in the debate on side-stream smoke. It affirms the federal government's position on the need to create more smoke-free environments and impose stronger smoking restrictions nationwide.

The health consequences of smoking. Cardiovascular diseases

Cigarette smoking is a major cause of atherosclerotic diseases. Cardiovascular diseases (CVD) remain the leading disease cause of death and disability in the United States. Smoking contributes to much of the premature and overall disease burden from CVD. Smoking affects the physiologic, pathologic, hematologic, and metabolic factors that lead to the initiation, progression, and sequelae of atherosclerosis. Smoking cessation reduces the progression of atherosclerosis and the subsequent morbidity, mortality, and years of productive life lost from CVD.