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

Experimental study of environmental tobacco smoke particles under actual indoor environment

Environmental tobacco smoke (ETS) is a major source of human exposure to airborne particles. In order to provide more information necessary for human exposure investigations, the aim of the work presented here is to investigate experimentally the variation of the ETS particle concentration and size distribution under an actual indoor environment, in a room of 30 m3, using human smokers. The effect of number of cigarettes and brands of cigarettes, the effect of sampling location and the effect of ventilation rates were investigated. The results indicated little difference in the geometric mean diameter (GMD) of the ETS particles from those in background air. Under a ventilation rate of 0.03 m3/s, the concentration of the ETS particles reached a peak value at the sampling point shortly after completing the smoking process. The GMD first increased due to coagulation and diffusion deposition, and finalize decreased due to the effect of ventilation. Smoking two cigarettes at the same time would increase the initial concentration and led to an increase in GMD of the ETS particles. Two different brands of cigarette with different tar contents released ETS particles of different GMDs but similar particle concentrations. Spatial variation in particle concentration was obvious only in the first 600 s of the tests and tended to fade out subsequently. Stronger ventilation would reduce the concentration and GMD of the particles.

Environmental tobacco smoke and mortality in Chinese women who have never smoked: prospective cohort study

OBJECTIVE

To evaluate the association of environmental exposure to tobacco smoke from husbands and from work, as well as from family members in early life, with all cause mortality and mortality due to cancer or cardiovascular disease in Chinese women.

DESIGN

Ongoing prospective cohort study in Shanghai, China.

PARTICIPANTS

Of 72,829 women who had never smoked, 65,180 women provided information on smoking by their husbands, and 66,520 women provided information on exposure to tobacco smoke at work and in early life from family members.

MAIN OUTCOME MEASURES

All cause mortality and cause specific mortality with the main focus on cancer and cardiovascular disease. Cumulative mortality according to exposure status, and hazard ratios.

RESULTS

Exposure to tobacco smoke from husbands (mainly current exposure) was significantly associated with increased all cause mortality (hazard ratio 1.15, 95% confidence interval 1.01 to 1.31) and with increased mortality due to cardiovascular disease (1.37, 1.06 to 1.78). Exposure to tobacco smoke at work was associated with increased mortality due to cancer (1.19, 0.94 to 1.50), especially lung cancer (1.79, 1.09 to 2.93). Exposure in early life was associated with increased mortality due to cardiovascular disease (1.26, 0.94 to 1.69).

CONCLUSIONS

In Chinese women, exposure to environmental tobacco smoke is related to moderately increased risk of all cause mortality and mortality due to lung cancer and cardiovascular disease.

Tobacco use and risk of myocardial infarction in 52 countries in the INTERHEART study: a case-control study

BACKGROUND

Tobacco use is one of the major avoidable causes of cardiovascular diseases. We aimed to assess the risks associated with tobacco use (both smoking and non-smoking) and second hand tobacco smoke (SHS) worldwide.

METHODS

We did a standardised case-control study of acute myocardial infarction (AMI) with 27,089 participants in 52 countries (12,461 cases, 14,637 controls). We assessed relation between risk of AMI and current or former smoking, type of tobacco, amount smoked, effect of smokeless tobacco, and exposure to SHS. We controlled for confounders such as differences in lifestyles between smokers and non-smokers.

FINDINGS

Current smoking was associated with a greater risk of non-fatal AMI (odds ratio [OR] 2.95, 95% CI 2.77-3.14, p<0.0001) compared with never smoking; risk increased by 5.6% for every additional cigarette smoked. The OR associated with former smoking fell to 1.87 (95% CI 1.55-2.24) within 3 years of quitting. A residual excess risk remained 20 or more years after quitting (1.22, 1.09-1.37). Exclusion of individuals exposed to SHS in the never smoker reference group raised the risk in former smokers by about 10%. Smoking beedies alone (indigenous to South Asia) was associated with increased risk (2.89, 2.11-3.96) similar to that associated with cigarette smoking. Chewing tobacco alone was associated with OR 2.23 (1.41-3.52), and smokers who also chewed tobacco had the highest increase in risk (4.09, 2.98-5.61). SHS was associated with a graded increase in risk related to exposure; OR was 1.24 (1.17-1.32) in individuals who were least exposed (1-7 h per week) and 1.62 (1.45-1.81) in people who were most exposed (>21 h per week). Young male current smokers had the highest population attributable risk (58.3%; 95% CI 55.0-61.6) and older women the lowest (6.2%, 4.1-9.2). Population attributable risk for exposure to SHS for more than 1 h per week in never smokers was 15.4% (12.1-19.3).

CONCLUSION

Tobacco use is one of the most important causes of AMI globally, especially in men. All forms of tobacco use, including different types of smoking and chewing tobacco and inhalation of SHS, should be discouraged to prevent cardiovascular diseases.

Predictors of support for environmental tobacco smoke bans in state government

BACKGROUND

Environmental tobacco smoke (ETS) is a major threat to public health, associated with a number of serious diseases, and a leading cause of death. Previous research demonstrates that enactment of government policies mandating clean indoor air is effective in creating more smoke-free public places and decreasing the incidence of smoking. Both researchers and community activists have an interest in understanding the factors that predict support for the regulation of ETS.

METHODS

This study examined predictors of support for regulating ETS by surveying 684 city and county public officials in Colorado who were interviewed by phone and mail (response rate 61%).

RESULTS

Thirty-five percent of public officials reported that it is a "serious" or "very serious" problem that nonsmokers breathe in other people's cigarette smoke, 21% were "neutral," and 42% said that it was "not serious" or "not serious at all." Results indicated that support for policies to control ETS and promote clean indoor air is significantly more prevalent among public officials who: (1) believe that tobacco use is a serious problem in their community, (2) believe that breathing environmental tobacco smoke is a serious problem for nonsmokers, (3) believe that city and county government should get involved with people's decisions about smoking, (4) support smoking-cessation programs for public employees, and (5) have smoked less than 100 cigarettes during their lifetime.

CONCLUSIONS

Both the harms of ETS and legislation to create smoke-free environments remain controversial among local officials. Smoke-free advocates should support officials who believe that ETS is a problem and persuade officials on the harms of ETS and the need for government intervention.

Impact of repeated lifestyle counselling in an atherosclerosis prevention trial on parental smoking and children's exposure to tobacco smoke

AIM

To determine whether repeated infancy-onset lifestyle counselling alters parental smoking and children's exposure to tobacco smoke.

METHODS

In 1990, 1062 healthy infants were recruited to a randomized, ongoing atherosclerosis prevention trial (STRIP). Intervention families received at least twice a year individualized nutrition and lifestyle counselling. By 1999, 652 8-y-old children continued participation. Exposure to tobacco smoke was evaluated using serum cotinine concentration. Parents' smoking was also assessed using questionnaires and interviews.

RESULTS

Parents' smoking decreased during the study similarly in the intervention and control groups. Of the 8-y-old children, 46% had detectable serum cotinine concentration, suggesting exposure to tobacco smoke during the past few days. All children were non-smokers. Serum cotinine concentrations did not differ between the intervention and control children. Children's cotinine values were highest in the families where either father or both parents were smokers.

CONCLUSION

Participation in the atherosclerosis prevention trial slightly decreased smoking among the intervention and control parents. However, counselling led to no differences in parental smoking between the two groups, or in exposure of the intervention and control children to tobacco smoke. This study suggests that more detailed and targeted intervention is required to achieve a significant effect on children's tobacco smoke exposure.

Nicotine and non-nicotine smoking cessation pharmacotherapies

Cigarette smoking remains an important risk factor for premature cardiovascular disease and its complications. There are clear benefits of cigarette smoking cessation on the rate of clinical outcomes, and in addition to behavioral therapies, various pharmacologic strategies have been developed to help achieve this goal. First-line therapies include nicotine replacement and/or bupropion. Second-line treatments include clonidine and nortriptyline. Additional treatment strategies, with less proven efficacy, include monoamine oxidase inhibitors, selective serotonin reuptake inhibitors, opioid receptor antagonists, bromocriptine, antianxiety drugs, nicotinic receptor antagonists (eg, mecamylamine), and glucose tablets. Various approaches under investigation include the use of partial nicotine agonists (eg, varenicline), inhibitors of the hepatic P-450 enzyme (eg, methoxsalen), cannaboid-1 receptor antagonists (eg, rimonabant), and nicotine vaccines.

Guidelines for Prevention of Stroke in Patients With Ischemic Stroke or Transient Ischemic Attack

The aim of this new statement is to provide comprehensive and timely evidence-based recommendations on the prevention of ischemic stroke among survivors of ischemic stroke or transient ischemic attack. Evidence-based recommendations are included for the control of risk factors, interventional approaches for atherosclerotic disease, antithrombotic treatments for cardioembolism, and the use of antiplatelet agents for noncardioembolic stroke. Further recommendations are provided for the prevention of recurrent stroke in a variety of other specific circumstances, including arterial dissections; patent foramen ovale; hyperhomocysteinemia; hypercoagulable states; sickle cell disease; cerebral venous sinus thrombosis; stroke among women, particularly with regard to pregnancy and the use of postmenopausal hormones; the use of anticoagulation after cerebral hemorrhage; and special approaches for the implementation of guidelines and their use in high-risk populations.

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.

Workplace smoking related absenteeism and productivity costs in Taiwan

OBJECTIVE

To estimate productivity losses and financial costs to employers caused by cigarette smoking in the Taiwan workplace.

METHODS

The human capital approach was used to calculate lost productivity. Assuming the value of lost productivity was equal to the wage/salary rate and basing the calculations on smoking rate in the workforce, average days of absenteeism, average wage/salary rate, and increased risk and absenteeism among smokers obtained from earlier research, costs due to smoker absenteeism were estimated. Financial losses caused by passive smoking, smoking breaks, and occupational injuries were calculated.

RESULTS

Using a conservative estimate of excess absenteeism from work, male smokers took off an average of 4.36 sick days and male non-smokers took off an average of 3.30 sick days. Female smokers took off an average of 4.96 sick days and non-smoking females took off an average of 3.75 sick days. Excess absenteeism caused by employee smoking was estimated to cost USD 178 million per annum for males and USD 6 million for females at a total cost of USD 184 million per annum. The time men and women spent taking smoking breaks amounted to nine days per year and six days per year, respectively, resulting in reduced output productivity losses of USD 733 million. Increased sick leave costs due to passive smoking were approximately USD 81 million. Potential costs incurred from occupational injuries among smoking employees were estimated to be USD 34 million.

CONCLUSIONS

Financial costs caused by increased absenteeism and reduced productivity from employees who smoke are significant in Taiwan. Based on conservative estimates, total costs attributed to smoking in the workforce were approximately USD 1032 million.

Inmate exposure to secondhand smoke in correctional facilities and the impact of smoking restrictions

This study was undertaken to measure the passive smoking exposure of prisoners at three correctional facilities in the US and to evaluate the effectiveness of a ban on smoking in reducing these exposures at two of these facilities. The average weekly concentration of nicotine was measured in fixed locations within the correctional facilities using passive samplers. Samples were collected before and after a smoking ban was instituted, and after the policy was modified to allow smoking outdoors. Samples were collected in the living areas, near where inmates slept and watched TV, and in selected central facilities, including dining halls, visiting rooms, booking areas, and learning centers. Average weekly concentrations of nicotine were measured in 84 locations while smoking was allowed; changes in these concentrations were measured with 112 weekly samples 4 and 9 months after the policy restricting smoking was implemented The average concentrations of nicotine were high while smoking was allowed: most living and sleeping areas averaged 3-11 microg/m(3), but the gym that was used as a bunkroom averaged 25 microg/m(3); these values compare to an average of 2 microg/m(3) in the homes of smokers. The smoking ban significantly reduced nicotine concentrations in the living areas (P<0.01 at facility A and P<0.05 at facility B) to averages of 1.5-2.2 microg/m(3); all postban samples were less than 5 microg/m(3). In conclusion, secondhand smoke concentrations in correctional facilities can be quite high; however, policies banning smoking are effective in reducing, but not eliminating, these exposures.

The impact of environmental tobacco smoke on women's risk of dying from heart disease: a meta-analysis

OBJECTIVE

To review systematically and analyze the association between environmental tobacco smoke (ETS) exposure and the risk of dying from heart disease in women.

METHODS

We searched the English-language literature using MEDLINE (1966-April 2004), CINAHL, PsychInfo, and bibliographies of selected studies. We included studies that specifically addressed the association of ETS and heart disease mortality in women and had adequate controls and retrievable risk estimates. We looked for either cohort studies or randomized controlled trials. Studies were evaluated independently by two of the authors. Nine cohort studies were finally selected for analysis. We estimated the summary relative risk (RR) and associated 95% confidence intervals (95% CI) using a random-effects model.

RESULTS

Mean follow-up periods for these cohorts ranged from 6 to 39 years. Among non-smoking women, exposure to ETS was associated with a 15% increase in the risk of dying from heart disease compared with nonsmoking women not exposed to ETS (RR = 1.15, 95% CI 1.03-1.28, p < 0.05).

CONCLUSIONS

Among nonsmoking women, exposure to passive smoke increases the risk of dying from heart disease. In accordance with the newly developed guidelines by the American Heart Association for prevention of cardiovascular disease (CVD) in women, we recommend counseling women on reducing or avoiding ETS exposure.

Exposure to environmental tobacco smoke (ETS) and determinants of support for complete smoking bans in psychiatric settings

OBJECTIVE

To measure environmental tobacco smoke (ETS) exposure in psychiatric settings and to assess determinants of support for complete smoking bans.

DESIGN

Cross sectional study

SETTING

Dutch psychiatric hospitals, outpatient care institutions, and sheltered home facilities.

SUBJECTS

A random sample of 540 treatment staff, 306 attendants/nurses, and 93 patients.

MAIN OUTCOME MEASURES

Self reported ETS exposure, current smoking policy, compliance with smoking policy, beliefs about smoking bans.

RESULTS

87% of respondents were exposed to tobacco smoke in psychiatric institutions; 29% said that on an average day they were exposed to "a lot of smoke". Although ETS originates mainly from smoking patients, both non-compliance from patients and employees with existing bans resulted in non-smokers being exposed to ETS. Due to non-compliance, ETS exposure was quite high when there is a general smoking ban (designated areas option). Only with a complete ban was compliance good and employees sufficiently protected from ETS exposure. Psychiatrists, psychologists, physicians, attendants, and nurses were most concerned about resistance from patients, partly because of the fear of infringing on patients' freedom to smoke.

CONCLUSIONS

Complete smoking bans are the only way to fully protect those working in psychiatry from ETS exposure, mainly because general smoking bans are not sufficiently complied with. Communication strategies to improve compliance with complete bans are crucial to protect those working in psychiatry from ETS. Compliance could be improved by addressing the belief that the ban will effectively result in less ETS exposure and the issue of patients' freedom to smoke versus employees' right to work in a smoke-free environment.

Cigarette smoking and exposure to environmental tobacco smoke in China: the international collaborative study of cardiovascular disease in Asia

OBJECTIVES

We estimated the prevalence of cigarette smoking and the extent of environmental tobacco smoke exposure (ETS) in the general population in China.

METHODS

A cross-sectional survey was conducted on a nationally representative sample of 15540 Chinese adults aged 35-74 years in 2000-2001. Information on cigarette smoking was obtained by trained interviewers using a standard questionnaire.

RESULTS

The prevalence of current cigarette smoking was much higher among men (60.2%) than among women (6.9%). Among nonsmokers, 12.1% of men and 51.3% of women reported exposure to ETS at home, and 26.7% of men and 26.2% of women reported exposure to ETS in their workplaces. On the basis of our findings, 147358000 Chinese men and 15895000 Chinese women aged 35-74 years were current cigarette smokers, 8658000 men and 108402000 women were exposed to ETS at home, and 19072000 men and 55372000 women were exposed to ETS in their workplaces.

CONCLUSIONS

The high prevalence of cigarette smoking and environmental tobacco smoke exposure in the Chinese population indicates an urgent need for smoking prevention and cessation efforts.

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.

Smoking is an occupational hazard

BACKGROUND

Even though the prevalence of tobacco smoking has declined in the general population and among white-collar workers, the prevalence of tobacco smoking among blue-collar workers remains unacceptably high. Blue-collar workers experience greater exposure to workplace toxins which can add to, or even multiply, their risk of adverse health effects from tobacco smoking. Among blue-collar workers, workers in the restaurant, bar, and gaming industries are exposed to much higher levels of environmental tobacco smoke (ETS) than are office workers, and are at increased risk of cancer and cardiovascular diseases even if they are non-smokers themselves.

METHODS

The literature on health risks, and the disparity between white and blue collar workers in smoking prevalence, and the literature on various tobacco control strategies provide the sources on which this review is based.

CONCLUSIONS

Over the past 20 years, the accumulating scientific evidence about smoking as an occupational hazard has prompted the implementation of various educational, economic, and legal tobacco control strategies.

Passive smoking and risk of coronary heart disease and stroke: prospective study with cotinine measurement

OBJECTIVE

To examine the associations between a biomarker of overall passive exposure to tobacco smoke (serum cotinine concentration) and risk of coronary heart disease and stroke.

DESIGN

Prospective population based study in general practice (the British regional heart study).

PARTICIPANTS

4729 men in 18 towns who provided baseline blood samples (for cotinine assay) and a detailed smoking history in 1978-80.

MAIN OUTCOME MEASURE

Major coronary heart disease and stroke events (fatal and non-fatal) during 20 years of follow up.

RESULTS

2105 men who said they did not smoke and who had cotinine concentrations < 14.1 ng/ml were divided into four equal sized groups on the basis of cotinine concentrations. Relative hazards (95% confidence intervals) for coronary heart disease in the second (0.8-1.4 ng/ml), third (1.5-2.7 ng/ml), and fourth (2.8-14.0 ng/ml) quarters of cotinine concentration compared with the first (> or = 0.7 ng/ml) were 1.45 (1.01 to 2.08), 1.49 (1.03 to 2.14), and 1.57 (1.08 to 2.28), respectively, after adjustment for established risk factors for coronary heart disease. Hazard ratios (for cotinine 0.8-14.0 nu > or = 0.7 ng/ml) were particularly increased during the first (3.73, 1.32 to 10.58) and second five year follow up periods (1.95, 1.09 to 3.48) compared with later periods. There was no consistent association between cotinine concentration and risk of stroke.

CONCLUSION

Studies based on reports of smoking in a partner alone seem to underestimate the risks of exposure to passive smoking. Further prospective studies relating biomarkers of passive smoking to risk of coronary heart disease are needed.

Cardiovascular health and economic effects of smoke-free workplaces

PURPOSE

Smoking is the leading controllable risk factor for heart disease. Only about 69% of U.S. indoor workers are currently covered by a smoke-free workplace policy. This analysis projects the cardiovascular health and economic effects of making all U.S. workplaces smoke free after 1 year and at steady state.

METHODS

We estimated the number of U.S. indoor workers not covered by smoke-free workplace policies, and the effects of making all workplaces smoke free on smoking behavior and on the relative risks of acute myocardial infarctions and strokes. One-year and steady-state results were calculated using an exponential decline model. A Monte Carlo simulation was performed for a sensitivity analysis.

RESULTS

The first-year effect of making all workplaces smoke free would produce about 1.3 million new quitters and prevent over 950 million cigarette packs from being smoked annually, worth about 2.3 billion dollars in pretax sales to the tobacco industry. In 1 year, making all workplaces smoke free would prevent about 1500 myocardial infarctions and 350 strokes, and result in nearly $60 [corrected] in savings in direct medical costs. At steady state, 6250 myocardial infarctions and 1270 strokes would be prevented, and $279 million [corrected] would be saved in direct medical costs annually. Reductions in passive smoking would account for 60% of effects among acute myocardial infarctions.

CONCLUSION

Making all U.S. workplaces smoke free would result in considerable health and economic benefits within 1 year. Reductions in passive smoking would account for a majority of these savings. Similar effects would occur with enactment of state or local smoke-free policies.

Air Pollution and Cardiovascular Disease

Air pollution is a heterogeneous, complex mixture of gases, liquids, and particulate matter. Epidemiological studies have demonstrated a consistent increased risk for cardiovascular events in relation to both short- and long-term exposure to present-day concentrations of ambient particulate matter. Several plausible mechanistic pathways have been described, including enhanced coagulation/thrombosis, a propensity for arrhythmias, acute arterial vasoconstriction, systemic inflammatory responses, and the chronic promotion of atherosclerosis. The purpose of this statement is to provide healthcare professionals and regulatory agencies with a comprehensive review of the literature on air pollution and cardiovascular disease. In addition, the implications of these findings in relation to public health and regulatory policies are addressed. Practical recommendations for healthcare providers and their patients are outlined. In the final section, suggestions for future research are made to address a number of remaining scientific questions.

Reduced incidence of admissions for myocardial infarction associated with public smoking ban: before and after study

OBJECTIVE

To determine whether there was a change in hospital admissions for acute myocardial infarction while a local law banning smoking in public and in workplaces was in effect.

DESIGN

Analysis of admissions from December 1997 through November 2003 using Poisson analysis.

SETTING

Helena, Montana, a geographically isolated community with one hospital serving a population of 68 140.

PARTICIPANTS

All patients admitted for acute myocardial infarction.

MAIN OUTCOME MEASURES

Number of monthly admissions for acute myocardial infarction for people living in and outside Helena.

RESULTS

During the six months the law was enforced the number of admissions fell significantly (- 16 admissions, 95% confidence interval - 31.7 to - 0.3), from an average of 40 admissions during the same months in the years before and after the law to a total of 24 admissions during the six months the law was effect. There was a non-significant increase of 5.6 (- 5.2 to 16.4) in the number of admissions from outside Helena during the same period, from 12.4 in the years before and after the law to 18 while the law was in effect.

CONCLUSIONS

Laws to enforce smoke-free workplaces and public places may be associated with an effect on morbidity from heart disease.

Is depression a major risk factor for coronary disease? A systematic review of the epidemiologic evidence

My objective is to examine systematically the status of the current evidence for and against depression as an independent major risk factor for coronary disease. From English-language reports on depression and coronary disease in MEDLINE (1966-2002) and PsycINFO (1967-2002), and from informal searches, I selected all studies that addressed the specific questions related to the established criteria for risk-factor status: (1) strength of association, (2) prediction, (3) specificity, (4) consistency, (5) dose-response effect, (6) biological plausibility, and (7) response to treatment. I find that the evidence for depression as a coronary disease risk factor is good for four criteria: strength of association, prediction, consistency, and dose-response effect. The evidence on specificity and biological plausibility is fair. Due to the lack of definitive studies, there is currently insufficient evidence for cardiac risk reduction in response to treatment for depression. My conclusion is that the evidence for depression's role as an independent major risk factor for coronary disease is good in four areas, but not yet conclusive in three, pointing to the need for three types of studies: (1) prospective, observational studies that address specificity questions, (2) studies of biological mechanisms linking depression and coronary disease, and (3) clinical trials of treatments for depression in people with coronary disease or at high risk for developing coronary disease.

Evaluation of exposure to carbon monoxide associated with passive smoking

The current study measured breath carbon monoxide (CO) concentrations prior to and at prescribed time intervals after exposure to passive smoking under controlled conditions, along with the air CO concentration in the exposure room during the exposure periods. The postexposure breath CO levels were 1.4-2.7 times higher than the background breath CO levels after 30 min of exposure, yet only slightly higher after 10 min of exposure, thereby confirming that exposure to CO from passive smoking causes a significant body burden of CO. The air CO concentration gradually increased during the burning of a cigarette(s), regardless of the exposure duration, whereas it slightly decreased after burning. However, the pattern of breath CO decay was similar for the two different types of exposure (during and after a cigarette(s)) in each subject. The decrease in the postexposure alveolar CO concentrations was slow even in the early phase of the decay curves, indicating a monocompartment uptake and elimination model for the human body. The half-lives (78-277 min) estimated in the present study were comparable to those reported in previous studies associated with CO exposure from active smoking or other activities. The current study also evaluated the CO exposure of visitors and workers at three different types of recreation facility (bars, Internet cafes, and billiard halls) typically associated with passive smoking. The results confirmed that passive smoking is the major contributor to the CO exposure of nonsmoking visitors in a recreation environment. In addition, workplace exposure to CO from passive smoking was found to be the most important contributor to the daily CO exposure of nonsmoking recreation workers.

Active and Passive Smoking and the Risk of Subarachnoid Hemorrhage

Background and Purpose— This study was undertaken to better clarify the risks associated with cigarette smoking and subarachnoid hemorrhage (SAH).

Methods— The study included 432 incident cases of SAH frequency matched to 473 community SAH-free controls to determine dose-dependent associations of active and passive smoking (at home) and smoking cessation with SAH.

Results— Compared with never smokers not exposed to passive smoking, the adjusted odds ratio for SAH among current smokers was 5.0 (95% confidence interval [CI], 3.1 to 8.1); for past smokers, 1.2 (95% CI, 0.8 to 2.0); and for passive smokers, 0.9 (95% CI, 0.6 to 1.5). Current and lifetime exposures showed a clear dose-dependent effect, and risks appeared more prominent in women and for aneurysmal SAH. Approximately 1 in 3 cases of SAH could be attributed to current smoking, but risks decline quickly after smoking cessation, even among heavy smokers.

Conclusions— A strong positive association was found between cigarette smoking and SAH, especially for aneurysmal SAH and women, which is virtually eliminated within a few years of smoking cessation. Large opportunities exist for preventing SAH through smoking avoidance and cessation programs.

Support for smoking restrictions in bars and gaming areas: review of Australian studies

OBJECTIVE

To document levels of public support in Australia for smoking restrictions in licensed premises, including trends over time, and to examine the potential effects of a ban on patronage.

METHOD

Systematic review of published and unpublished studies of community and staff attitudes towards smoking in bars, gaming areas and related venues were identified using Medline, Current Contents, PsycINFO and AUSTHealth prior to September 2002. State and Territory health departments, cancer organisations and branches of the National Heart Foundation were approached. Cross-sectional surveys reporting data on attitudes towards smoking restrictions and/or perceptions of effects on patronage were sought. Two reviewers assessed studies for inclusion. One extracted data using pre-coded categories with checking by the second.

RESULTS

Thirty-four community and seven staff surveys were synthesised qualitatively, with greater emphasis given to surveys using random selection. All surveys conducted since 1993, which included the separate smoking area response option, have demonstrated majority support for some form of smoking restriction on licensed premises. From 2000, surveys with the ban option alone report majority support for prohibiting smoking completely in bars (52-68%) and gaming areas (64-76%). Support increased significantly after the Sharp damages award. Customer preference data indicate banning smoking is most likely to have a neutral or positive effect on patronage.

CONCLUSIONS AND IMPLICATIONS

Support for a ban on smoking in licensed premises has increased by almost 20% in the past decade. State and Territory governments should introduce legislation banning smoking in all indoor drinking and gaming areas immediately.

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.

Effect of exposure to secondhand smoke on markers of inflammation: the ATTICA study

PURPOSE

We sought to investigate the effect of secondhand smoke exposure on inflammatory markers related to cardiovascular disease.

METHODS

During 2001 to 2002, we randomly selected a stratified (age-sex) sample of adults without clinical evidence of cardiovascular disease. Exposure to secondhand smoke (>30 minutes per day and > or =1 day per week) was recorded. Multivariate regression analysis was used to evaluate the effects of exposure to secondhand smoke on levels of C-reactive protein, fibrinogen, homocysteine, and oxidized low-density lipoprotein (LDL) cholesterol, and on white blood cell count.

RESULTS

One hundred and thirty-seven (38%) of the 357 men who had never smoked and 211 (33%) of the 638 never-smoking women reported current exposure to secondhand smoke. Compared with those who were not exposed to secondhand smoke, those exposed more than 3 days per week had higher white blood cell counts (by 600 cells per microL; P = 0.02), as well as higher levels of C-reactive protein (by 0.08 mg/dL; P = 0.03), homocysteine (by 0.4 micromol/L; P = 0.002), fibrinogen (by 5.2 mg/dL; P = 0.4), and oxidized LDL cholesterol (by 3.3 mg/dL; P = 0.03), after adjusting for several potential confounders.

CONCLUSION

Our findings suggest another pathophysiological mechanism by which exposure to secondhand smoke is associated with the development of atherosclerosis.

Sociodemographic correlates of public perceptions regarding a smoking ban in bars and restaurants

As the health threat of environmental tobacco smoke is widely recognized, more state and local governments join the passage of ordinances that ban smoking in public establishments. This study investigated public perceptions regarding banning smoking in bars and restaurants among Indiana residents. A representative sample of 529 adult Indiana residents ages 18 or older was interviewed using random-digit dialing after two waves of pilot tests. Of the total respondents, 65% favored the smoking ban in bars and restaurants. Logistic regression analyses indicated that gender, education, and spouse's education were significant predictors for attitudes toward the smoking ban in bars and restaurants.

Delineating mechanisms of change in child and adolescent therapy: methodological issues and research recommendations

BACKGROUND

Mechanisms of therapeutic change are rarely studied in child and adolescent therapy. Our central thesis is that the study of mechanisms of treatment is an excellent investment for improving clinical practice and patient care. Indeed, extending treatment trials to clinical settings, without complementary research that studies why and how treatment works, could have great limitations.

METHOD

In this article, we discuss the importance of studying mechanisms, the logical and methodological requirements, and why almost no studies to date provide evidence for why or how treatment works. Standard statistical practices (tests of mediation) and designs (randomized controlled clinical trials) contribute greatly to outcome research but have little to say about mechanisms given the way they are commonly used.

CONCLUSIONS

The article ends with recommendations to guide research on mechanisms of therapeutic change.

Environmental tobacco smoke and carotid arterial stiffness

BACKGROUND

Although active smoking acutely increases arterial stiffness, the association between arterial stiffness and chronic exposure to environmental tobacco smoke (ETS) has not been evaluated. We used baseline data from the Vitamin E Atherosclerosis Prevention Study to evaluate the association between ETS exposure and arterial stiffness among 227 healthy adult nonsmokers.

METHODS

B-mode ultrasonograms of the common carotid artery were used to compute the carotid arterial wall stiffness index beta. Beta was compared by the number of sources and daily hours of ETS exposure.

RESULTS

The carotid stiffness index beta was positively associated with age, body mass index (BMI), fasting glucose, and common carotid artery intima-media thickness (IMT). In the total sample, beta was not related to the number of ETS exposure sources. The carotid stiffness index beta increased with number of sources and daily hours of ETS in subjects with BMI > or =27.1 kg/m2 and IMT > or =0.707 mm. The association was not apparent in subjects with lower BMI or IMT (for number of ETS sources, interaction P values=0.006 and 0.01, respectively). For number of ETS sources, but not hours of exposure, positive associations were apparent among females (but not males) and among subjects > or =55 years old (but not younger subjects).

CONCLUSIONS

These data indicate that arterial stiffness is adversely associated with ETS in a dose-dependent manner among individuals with higher BMI and greater carotid artery IMT.

Oxidative stress and smoking-induced vascular injury

The relative importance of mechanisms relevant to smoking-induced vascular injury is poorly understood. Cigarette smoke is a source of free radicals but also results in cellular activation and consequent generation of free radicals in vivo. Here we consider several approaches to estimating the consequences of free radical generation in vivo, using measurements of modified lipids, proteins, and DNA. Smoking appears to result in elevation of several biomarkers of oxidant stress, some in a dose-related fashion. There is also some evidence that disordered endothelial function in smokers may be partly attributable to oxidant stress. Other effects of smoking on hemostatic activation, sympathoadrenal function, and lipoprotein structure and function may also be modulated by smoking-induced oxidant stress. The emergence and application of rational quantitatively reliable indexes of oxidant stress in vivo is likely to elucidate the relative contribution of oxidant stress to smoking-induced vascular injury.

Tobacco cessation in primary care: maximizing intervention strategies

The most effective preventive intervention that a clinician can provide for tobacco-using patients against heart disease, cancer, cerebrovascular disease and chronic obstructive pulmonary disease is an empathic, personalized smoking cessation intervention program with extended assistance and follow-up. The goal of the intervention must be complete smoking cessation. Reduction provides no direct health benefits to the individual smoker. Interventions are readily available, but underutilized, in part due to lack of clinician training and organizational support. The present article summarizes the current guidelines for smoking cessation interventions as a framework from which to start. The guidelines incorporate the Transtheoretical Model of patient behavioral change and the "Five A's": Ask, Advise, Assess, Assist and Arrange. Pharmacotherapeutic tools, including nicotine replacement therapies (nicotine gums, patches, nasal sprays, inhalers and new therapies) and non-nicotine therapies (bupropion, clonidine, nortriptyline and other antidepressants and anxiolytics) are considered. Adherence validation methods, new approaches to tobacco and addiction treatment that appear in the recent research literature are reviewed. Beyond this framework, specific categories of tobacco users (including smokeless tobacco users), cultural and ethnic minorities, adolescents using snuff and bidis, women, Medicaid recipients, and users of multiple forms of tobacco require special consideration. With this framework and the modifications that may be required for specific categories of patients, practicing clinicians can incorporate into daily practice a successful tobacco cessation intervention program with quit rates approaching 20%.

Environmental tobacco smoke and ischemic heart disease

Cohort and case control studies show a 30% excess risk of ischemic heart disease in nonsmokers whose spouses smoke compared with that in nonsmokers whose spouses do not smoke. There is a nonlinear dose-response; the excess risk from actively smoking 20 cigarettes/day is only 80%. Large cohort studies of active smoking support the nonliner dose-response (the excess risk in smokers of 5 cigarettes/day is about 50%). Animal studies show a pronounced vascular effect of environmental tobacco smoke. In experimental studies passive and active smoking have similar effects on platelet aggregation. The collective evidence supports a significant effect of low dose tobacco smoke exposure in causing ischaemic heart disease.

Environmental tobacco smoke and tobacco related mortality in a prospective study of Californians, 1960-98

OBJECTIVE

To measure the relation between environmental tobacco smoke, as estimated by smoking in spouses, and long term mortality from tobacco related disease.

DESIGN

Prospective cohort study covering 39 years.

SETTING

Adult population of California, United States.

PARTICIPANTS

118 094 adults enrolled in late 1959 in the American Cancer Society cancer prevention study (CPS I), who were followed until 1998. Particular focus is on the 35 561 never smokers who had a spouse in the study with known smoking habits.

MAIN OUTCOME MEASURES

Relative risks and 95% confidence intervals for deaths from coronary heart disease, lung cancer, and chronic obstructive pulmonary disease related to smoking in spouses and active cigarette smoking.

RESULTS

For participants followed from 1960 until 1998 the age adjusted relative risk (95% confidence interval) for never smokers married to ever smokers compared with never smokers married to never smokers was 0.94 (0.85 to 1.05) for coronary heart disease, 0.75 (0.42 to 1.35) for lung cancer, and 1.27 (0.78 to 2.08) for chronic obstructive pulmonary disease among 9619 men, and 1.01 (0.94 to 1.08), 0.99 (0.72 to 1.37), and 1.13 (0.80 to 1.58), respectively, among 25 942 women. No significant associations were found for current or former exposure to environmental tobacco smoke before or after adjusting for seven confounders and before or after excluding participants with pre-existing disease. No significant associations were found during the shorter follow up periods of 1960-5, 1966-72, 1973-85, and 1973-98.

CONCLUSIONS

The results do not support a causal relation between environmental tobacco smoke and tobacco related mortality, although they do not rule out a small effect. The association between exposure to environmental tobacco smoke and coronary heart disease and lung cancer may be considerably weaker than generally believed.

Do depressive symptoms increase the risk for the onset of coronary disease? A systematic quantitative review

OBJECTIVE

The objectives of this study were to systematically review the recent studies of the contribution of depression to the onset of coronary disease and to estimate the magnitude of the risk posed by depression for onset of coronary disease.

METHOD

We searched MEDLINE (1966-2000), PsychInfo (1967-2000), and cross references and conducted informal searches for all community studies of depression symptoms in samples with no clinically apparent heart disease at baseline. From these studies we selected all published cohort studies of 4 years or more follow-up that controlled for other major coronary disease risk factors and reported relative risks (or a comparable measure) of baseline depression for the onset of coronary disease. Following methods for the meta-analysis of epidemiologic studies, we used a random-effects model to estimate the combined overall relative risk.

RESULTS

Ten studies met our inclusion criteria. Relative risks ranged from 0.98 to 3.5. Nine studies reported significantly increased risk, including two with mixed results; one study reported no increased risk. The combined overall relative risk of depression for the onset of coronary disease was 1.64 (95% CI = 1.41-1.90).

CONCLUSIONS

This quantitative review suggests that depressive symptoms contribute a significant independent risk for the onset of coronary disease, a risk (1.64) that is greater than the risk conferred by passive smoking (1.25) but less than the risk conferred by active smoking (2.5). Future prospective community studies should examine the effect of severity and duration of depressive symptoms and disorders on the risk for the onset of coronary disease.

Passive smoking and vascular disease

Passive smoking, or environmental tobacco smoke, is a causative factor in cardiovascular disease. A 30-minute passive smoking exposure was found to affect coronary flow velocity reserve in nonsmokers, indicating endothelial dysfunction in coronary circulation. This article summarizes empirical work on passive smoking and heart disease. Clinically relevant findings include a dose-response relationship between passive smoking exposure and heart disease and partial reversibility of physical effects after eliminating passive smoking exposure. Appropriate assessment of passive smoking exposure in a variety of settings is warranted, as well as recommendations to avoid such exposure. Policy-based public health initiatives to eliminate passive smoking in the workplace and other public areas are needed.

Environmental tobacco smoke in homes, motor vehicles and licensed premises: community attitudes and practices

OBJECTIVE

To assess community knowledge, attitudes and practices in relation to environmental tobacco smoke (ETS) especially in homes, private motor vehicles and licensed premises, and to document levels of support for further government legislation.

METHODS

656 persons aged 18 years and over, a sub-sample in a computer-assisted telephone survey of 2,087 randomly selected respondents across NSW, answered 12 ETS-specific questions. The whole sample was asked demographic, smoking status and household membership questions. The overall response rate was 61.4% (consent rate 75.4%).

RESULTS

Overall, 32.8% (95% CI 27.8-37.8) of children aged 0-4 years in the households surveyed were reported to live with at least one smoker. Agreement about ETS hazards was lowest in relation to child ear problems (31.2%) and sudden infant death syndrome (50.6%). Complete bans on smoking were reported in 69.9% of homes and 77.1% of private motor vehicles. The percentages favouring total bans in homes (p < 0.001) and private motor vehicles (p < 0.001) were significantly lower among smokers than non-smokers. Overall, 55.8% supported legislation to ban smoking in private vehicles carrying children. The majority support restrictions on smoking in non-eating areas of licensed clubs (88.7%) and hotels (84.8%). Overall, the data indicate a ban on smoking in licensed premises is likely to increase business.

CONCLUSION

Smoking is banned in most NSW homes and private motor vehicles. Acceptance of ETS risks is high but there are important knowledge gaps. Considerable support exists for further government regulation of ETS. Media campaigns are likely to reinforce a public environment already receptive of the need for more government ETS restrictions.

[Epidemiological study of risk behaviour in adolescents at school in two populations, semi-rural and urban]

OBJECTIVE

Describe the risk behavior relationships existing in school adolescents between themselves and with the place of residence.

DESIGN

Cross-sectional descriptive study.

PARTICIPANTS

School students from Cabra (semi-rural, 1319 students) and from one high school in Las Palmas de Gran Canaria (urban: 1,751 students).

SAMPLE POPULATION

n=738 (368/370). Sampling unit classroom. MEASUREMENTS AND MAIN RESULTS. Anonymous, self-filled questionnaire, with several subjects: demographic data, traffic-related risk conducts, alcohol consumption, tobacco, other drugs, sexuality, physical exercise and dietetic habits.

SELECTION CRITERIA

attendance at class on the day of the questionnaire and age 15-21. The relationship between variables was studied by logistical regression and multiple correspondence analysis (MCA); odds ratio (OR: logistical regression) with 95% confidence intervals (CI) were calculated. Median age: Cabra 17.6 (CI, 17.5-17.8), Las Palmas 16.4 (CI, 16.2-16.5). Those living in Las Palmas have a higher risk of heavy drinking on weekends (OR, 3.2; CI, 1.9-5.1), of being offered drugs (OR, 4.5; CI, 3.1-6.5) and of consuming them (OR, 4.1; CI, 2.1-8.3), as well as of having sexual intercourse (OR, 2.5; CI, 1.6-3.8). In the MCA tobacco, alcohol and other drug use, having sexual intercourse and not doing regular physical exercise were closely-located within themselves.

CONCLUSIONS

Risk behaviours are interrelated and influenced by the habitat, and start to appear at the beginning of the adolescence.

Association between exposure to environmental tobacco smoke and the development of acute coronary syndromes: the CARDIO2000 case-control study

OBJECTIVE

To investigate the association between environmental tobacco smoke (ETS) exposure (at least 30 minutes a day) and the risk of developing acute coronary syndromes (ACS).

DESIGN AND SETTING

The CARDIO2000 is a case-control study which was conducted in Greece from 2000 to 2001. Cases included 847 individuals with a first event of ACS and 1078 cardiovascular disease-free controls. Cases and controls were frequency matched on age (within three years of age), sex, and region.

MAIN OUTCOME MEASURES

ACS was defined as a diagnosis of first acute myocardial infarction or unstable angina. Main independent variable: Exposure to ETS was measured by self report as follows: after the second day of hospitalisation for the cases, and at the entry for the controls, participants were asked whether they were currently exposed to tobacco smoke from other people (home and/or work) for more than 30 minutes a day. The responses were categorised into three levels: no exposure, occasional exposure (< 3 times per week), and regular exposure. In addition participants were asked how many years they had been exposed. Because these were self reported assessments and prone to bias, the results were compared to reports obtained from subjects' relatives or friends, using the Kendal's tau coefficient that showed high agreement.

RESULTS

731 (86%) of the patients and 605 (56%) of the controls reported current exposure of 30 minutes per day or more to ETS. Among current non-smokers, cases were 47% more likely to report regular exposure to ETS (odds ratio (OR) 1.47, 95% confidence interval (CI) 1.26 to 1.80) compared to controls. Exposure to ETS at work was associated with a greater risk of ACS compared to home exposure (+97% v +33%). The risk of ACS was also raised in active smokers (OR 2.83, 95% CI 2.07 to 3.31) regularly exposed to ETS.

CONCLUSIONS

This study supports the hypothesis that exposure to ETS increases the risk of developing ACS. The consistency of these findings with the existing totality of evidence presented in the literature supports the role of ETS in the aetiology of ACS.

Science, politics, and ideology in the campaign against environmental tobacco smoke

The issue of environmental tobacco smoke (ETS) and the harms it causes to nonsmoking bystanders has occupied a central place in the rhetoric and strategy of antismoking forces in the United States over the past 3 decades. Beginning in the 1970s, anti-tobacco activists drew on suggestive and incomplete evidence to push for far-reaching prohibitions on smoking in a variety of public settings. Public health professionals and other antismoking activists, although concerned about the potential illness and death that ETS might cause in nonsmokers, also used restrictions on public smoking as a way to erode the social acceptability of cigarettes and thereby reduce smoking prevalence. This strategy was necessitated by the context of American political culture, especially the hostility toward public health interventions that are overtly paternalistic.

The association between secondhand smoke and the risk of developing acute coronary syndromes, among non-smokers, under the presence of several cardiovascular risk factors: The CARDIO2000 case-control study

BACKGROUND

The purpose of this study was to investigate the association between secondhand smoke and the risk of developing a first event of acute coronary syndromes (ACS), i.e. acute myocardial infarction or unstable angina, among non-smokers, in relation to the presence of several other cardiovascular risk factors.

METHODS

Eight hundred and forty-eight patients with first event of ACS and 1078 cardiovascular disease-free matched controls completed a detailed questionnaire regarding their exposure to secondhand smoke, among other investigated parameters.

RESULTS

Two hundred and ninety-seven (35%) of the patients and 259 (24%) of the controls were defined as secondhand smokers. After controlling for several potential confounders, the results showed that non-smokers occasionally (< 3 time per week) exposed to cigarette smoke were associated with 26% higher risk of ACS (OR = 1.26, P-value < 0.01) compared to non-smokers not exposed to smoke, while regular exposure is associated with 99% higher risk of developing ACS (OR = 1.99, P-value < 0.001). Moreover, the previous risk increases progressively from 15% to 256% if one or more of the classical cardiovascular risk factors (i.e. hypertension, hypercholesterolemia, diabetes mellitus, sedentary life and family history of premature coronary heart disease) are present.

CONCLUSIONS

Consequently, this study supports the hypothesis that even occasional secondhand smoke increases the risk of developing acute coronary syndromes, especially when other risk factors are present. Given the high prevalence of cigarette smoking, the public health consequences of passive smoking with regard to coronary heart disease are important.

Reducing global risk for cardiovascular disease: using lifestyle changes and pharmacotherapy

Cardiovascular disease (CVD) is the leading cause of death and disability in industrialized societies, due in large part to the lack of a comprehensive approach to control the risk factors for atherosclerosis. One strategy for reducing an individual's global CVD risk relies on a targeted approach that modifies each of the major independent risk factors prevalent in both symptomatic (secondary prevention) and asymptomatic (primary prevention) patients. These interventions include lipid lowering, smoking cessation, blood pressure control, glycemic control, regular exercise, and the use of various medications. This review offers an evidence-based strategy toward reducing an individual's global risk for CVD by addressing the modifiable, major independent risk factors.

Socioeconomic differences in children's health: how and why do these relationships change with age?

The effects of socioeconomic status (SES) on health are well documented in adulthood, but far less is known about its effects in childhood. The authors reviewed the literature and found support for a childhood SES effect, whereby each decrease in SES was associated with an increased health risk. The authors explored how this relationship changed as children underwent normal developmental changes and proposed 3 models to describe the temporal patterns. The authors found that a model's capacity to explain SES-health relationships varied across health outcomes. Childhood injury showed stronger relationships with SES at younger ages, whereas smoking showed stronger relationships with SES in adolescence. Finally, the authors proposed a developmental approach to exploring mechanisms that link SES and child health.