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

Declines in hospital admissions for acute myocardial infarction in New York state after implementation of a comprehensive smoking ban

OBJECTIVES

Reductions in exposure to environmental tobacco smoke have been shown to attenuate the risk of cardiovascular disease. We examined whether the 2003 implementation of a comprehensive smoking ban in New York State was associated with reduced hospital admissions for acute myocardial infarction and stroke, beyond the effect of moderate, local and statewide smoking restrictions, and independent of secular trends.

METHODS

We analyzed trends in county-level, age-adjusted, monthly hospital admission rates for acute myocardial infarction and stroke from 1995 to 2004 to identify any association between admission rates and implementation of the smoking ban. We used regression models to adjust for the effects of pre-existing smoking restrictions, seasonal trends in admissions, differences across counties, and secular trends.

RESULTS

In 2004, there were 3813 fewer hospital admissions for acute myocardial infarction than would have been expected in the absence of the comprehensive smoking ban. Direct health care cost savings of $56 million were realized in 2004. There was no reduction in the number of admissions for stroke.

CONCLUSIONS

Hospital admission rates for acute myocardial infarction were reduced by 8% as a result of a comprehensive smoking ban in New York State after we controlled for other relevant factors. Comprehensive smoking bans constitute a simple, effective intervention to substantially improve the public's health.

Increase in saliva cotinine after three hours' exposure to second-hand smoke in bars

OBJECTIVE

To determine whether measurement of cotinine in saliva is a sensitive measure of exposure to second-hand smoke (SHS) among customers in bars.

DESIGN

Before/after comparison of saliva cotinine and subjective assessments of SHS.

SETTING

Three bars in Wellington, New Zealand, June 2003.

PARTICIPANTS

Eleven non-smoking medical students spent three hours in each location. They provided saliva samples before and after the visit, counted numbers of lit cigarettes in each bar, and assessed the smokiness of the venue. Samples were tested for cotinine using liquid chromatography coupled with mass spectrometry.

RESULTS

Cotinine levels post-visit were consistently higher than baseline. The mean difference was 1.03 ng/mL with a 95% confidence interval of 0.76-1.30 ng/ mL. Adjustments to post-visit levels for metabolism and clearance of cotinine made very little difference to these results. Males tended to have higher baseline levels than females, and to show smaller increases. The bar with the greatest increase in cotinine was judged to be the smokiest on the basis of averaged cigarette counts and scores for presence of smoke and odour.

CONCLUSION

The cotinine in saliva, when tested with the analytic methods described here, provides a means of assessing relatively short-term exposures to SHS.

Changes in exposure of adult non-smokers to secondhand smoke after implementation of smoke-free legislation in Scotland: national cross sectional survey

OBJECTIVE

To measure change in adult non-smokers' exposure to secondhand smoke in public and private places after smoke-free legislation was implemented in Scotland.

DESIGN

Repeat cross sectional survey.

SETTING

Scotland.

PARTICIPANTS

Scottish adults, aged 18 to 74 years, recruited and interviewed in their homes.

INTERVENTION

Comprehensive smoke-free legislation that prohibits smoking in virtually all enclosed public places and workplaces, including bars, restaurants, and cafes.

OUTCOME MEASURES

Salivary cotinine, self reported exposure to smoke in public and private places, and self reported smoking restriction in homes and in cars.

RESULTS

Overall, geometric mean cotinine concentrations in adult non-smokers fell by 39% (95% confidence interval 29% to 47%), from 0.43 ng/ml at baseline to 0.26 ng/ml after legislation (P<0.001). In non-smokers from non-smoking households, geometric mean cotinine concentrations fell by 49% (40% to 56%), from 0.35 ng/ml to 0.18 ng/ml (P<0.001). The 16% fall in cotinine concentrations in non-smokers from smoking households was not statistically significant. Reduction in exposure to secondhand smoke was associated with a reduction after legislation in reported exposure to secondhand smoke in public places (pubs, other workplaces, and public transport) but not in homes and cars. We found no evidence of displacement of smoking from public places into the home.

CONCLUSIONS

Implementation of Scotland's smoke-free legislation has been accompanied within one year by a large reduction in exposure to secondhand smoke, which has been greatest in non-smokers living in non-smoking households. Non-smokers living in smoking households continue to have high levels of exposure to secondhand smoke.

The impact of a smoking ban on hospital admissions for coronary heart disease

OBJECTIVE

In March 2002, the city of Bowling Green, Ohio, implemented a clean indoor air ordinance banning smoking in workplaces and public places. This study evaluates the effect of this ordinance on hospital admissions for smoking-related diseases.

METHODS

A quasi-experimental design with interrupted time-series was used including a matched control city (Kent, Ohio) with no clean indoor air ordinance. Data on hospital admissions during the period of January 1999 to June 2005 were analyzed using Autoregressive Integrated Moving Average (ARIMA) models.

RESULTS

A reduction in admission rates for smoking-related diseases was achieved in Bowling Green compared to the control city. The largest reduction was for coronary heart disease, where rates were decreased significantly by 39% after 1 year and by 47% after 3 years following the implementation of the ordinance. ARIMA models revealed a statistically significant downward trend in monthly admission rates for coronary heart disease (Bowling Green, omega=-1.69, p=0.036 vs. Kent, omega=-1.14, p=0.183) and support the hypothesis that the ordinance had a significant impact on admission rates for coronary heart disease.

CONCLUSION

The findings of this study suggest that clean indoor air ordinances lead to a reduction in hospital admissions for coronary heart disease, thus reducing health care costs.

Tobacco Smoke Exposure Is Associated With Attenuated Endothelial Function in 11-Year-Old Healthy Children

BACKGROUND

Passive smoking is associated with early arterial damage in adults, but its effect on endothelial function in children is unknown.

METHODS AND RESULTS

Serum cotinine concentration was measured annually in children between 8 and 11 years of age who had participated since infancy in a randomized, prospective atherosclerosis prevention trial (Special Turku Coronary Risk Factor Intervention Project for children [STRIP]). At age 11, endothelium-dependent flow-mediated vasodilatory responses of the brachial artery were examined with high-resolution ultrasound in 402 children. These children were divided into 3 groups according to serum cotinine concentrations: the noncotinine group (nondetectable cotinine, n=229), the low cotinine group (cotinine between 0.2 and 1.6 ng/mL, n=134), and the top decile cotinine group (cotinine > or = 1.7 ng/mL, n=39). Longitudinal cotinine data in children aged 8 to 11 years and ultrasound studies were available in 327 children. At age 11, the increase in cotinine concentration was associated with attenuated peak flow-mediated dilation response (mean+/-SD: the noncotinine group 9.10+/-3.88%, the low-cotinine group 8.57+/-3.78%, and the top-decile cotinine group 7.73+/-3.85%; P=0.03 for trend). Similarly, total dilation response (the area under the dilation response versus time curve between 40 and 180 seconds after hyperemia) was affected by the cotinine level (P=0.02 for trend). These trends were not explained by traditional atherosclerosis risk factors. Arterial measures and passive smoking showed even stronger associations when longitudinal cotinine data were used (peak flow-mediated dilation, P=0.01 for trend; total dilation response, P=0.008 for trend).

CONCLUSIONS

Exposure to environmental tobacco smoke confirmed by serum cotinine concentrations impairs endothelial function in a dose-dependent manner in 11-year-old children.

Cardiovascular effects of second-hand smoke help explain the benefits of smoke-free legislation on heart disease burden

Second-hand smoke (SHS) increases the risk of heart disease by approximately 30% in nonsmokers. Recent evidence from cities that have implemented 100% smoke-free laws has shown that myocardial infarction admissions rapidly declined after law implementation. This decline is, in part, explained by the acute and substantial cardiovascular effects of SHS, many of which are rapid and nearly as large as smoking. The cardiovascular effects of SHS include platelet activation, endothelial dysfunction, inflammation, atherosclerosis development and progression, increased oxidative stress, decreased energy metabolism, and increased insulin resistance. These effects are, on average, 80% to 90% that of chronic active smoking. However, cardiovascular function is partially recovered after SHS exposure ends. Given the evidence, cardiovascular nurses should advise their patients and relatives to avoid SHS exposure and demand smoke-free workplaces and homes.

Exposure to secondhand smoke and biomarkers of cardiovascular disease risk in never-smoking adults

BACKGROUND

Exposure to secondhand smoke has been associated with a disproportionately high risk of coronary heart disease, thought to be mediated through inflammation, platelet aggregation, and/or endothelial dysfunction. The epidemiological association between objectively measured exposure to secondhand smoke and biomarkers of heart disease risk has not been investigated, however.

METHODS AND RESULTS

We have investigated the cross-sectional relation between secondhand smoke exposure, measured objectively as cotinine, and recognized biomarkers of heart disease risk, namely C-reactive protein, homocysteine, fibrinogen, and white blood cell count, in 7599 never-smoking adults from the Third National Health and Nutrition Examination Survey. Compared with subjects with no detectable cotinine, those with detectable but low-level cotinine (range, 0.05 to 0.215 ng/mL) had significantly higher levels of both fibrinogen (adjusted mean difference, 8.9 mg/dL; 95% CI, 0.9 to 17.0; P=0.03) and homocysteine (0.8 micromol/L; 95% CI, 0.4 to 1.1; P<0.001) but not C-reactive protein or white blood cell count. Effect estimates of similar magnitude and significance were seen in subjects in the high category of cotinine exposure (>0.215 ng/mL). The increased levels of fibrinogen and homocysteine seen in relation to secondhand smoke exposure were equivalent to approximately 30% to 45% of those seen for active smoking.

CONCLUSIONS

Passive smokers appear to have disproportionately increased levels of 2 biomarkers of cardiovascular disease risk, fibrinogen and homocysteine. This finding provides further evidence to suggest that low-level exposure to secondhand smoke has a clinically important effect on susceptibility to cardiovascular disease.

The association between exposure to environmental tobacco smoke and breast cancer: a review by the California Environmental Protection Agency

BACKGROUND

The California Environmental Protection Agency (Cal/EPA) recently completed a health effects assessment of exposure to environmental tobacco smoke (ETS) which resulted in California listing ETS as a Toxic Air Contaminant in January 2006. As part of the assessment, studies on the association between exposure to ETS and breast cancer were reviewed.

METHODS

Twenty-six published reports (including 3 meta-analyses) evaluating the association between ETS exposure and breast cancer were reviewed. A weight-of-evidence approach was applied to evaluate the data and draw conclusions about the association between breast cancer and ETS exposure.

RESULTS

The published data indicate an association between ETS and breast cancer in younger primarily premenopausal women. Thirteen of 14 studies (10 case-control and four cohort) that allowed analysis by menopausal status reported elevated risk estimates for breast cancer in premenopausal women, seven of which were statistically significant. Our meta-analyses indicated elevated summary relative risks ranging from OR 1.68 (95% C.I. 1.31, 2.15) for all 14 studies to 2.20 (95% C.I. 1.69, 2.87) for those with the best exposure assessment.

CONCLUSIONS

Cal/EPA concluded that regular ETS exposure is causally related to breast cancer diagnosed in younger, primarily premenopausal women and that the association is not likely explained by bias or confounding.

Reduced admissions for acute myocardial infarction associated with a public smoking ban: matched controlled study

There has been no research linking implementation of a public smoking ban and reduced incidence of acute myocardial infarction (AMI) among nonsmoking patients. An ex post facto matched control group study was conducted to determine whether there was a change in hospital admissions for AMI among nonsmoking patients after a public smoking ban was implemented in Monroe County compared with Delaware County, Indiana without such a ban. Poisson analysis was conducted for 44 months of hospital admissions. A significant drop occurred in the number of admissions among nonsmoking patients in Monroe County after the ban whereas a nonsignificant decrease in the number of admissions occurred in Delaware County. The changes in the number of smoking-patient admissions before and after the ban were not significant.

DNA adducts in human placenta exposed to ambient environment and passive cigarette smoke during pregnancy

BACKGROUND

The risk of human diseases and abnormal development under the relatively reduced toxic environmental exposure conditions of passive cigarette smoke and urban pollution is emerging as significant. To assess the genotoxic potential of such exposure, we analyzed the DNA adducts of polynuclear aromatic hydrocarbons (PAH), a proven marker of genotoxicity, in human placental DNA samples of pregnancies monitored for passive cigarette smoke exposure.

METHODS

Maternal exposure to active and passive cigarette smoke was evaluated by verbal disclosure and urinary nicotine and cotinine measurements. PAH-DNA adducts were assayed by ELISA using a polyclonal antibody against benzo[alpha]pyrene-diol-epoxide-DNA in placental DNA. Birth weights of infants were recorded in these monitored pregnancies.

RESULTS

Urinary nicotine and cotinine values were reduced in the passive smoke-exposed group compared to smokers and similar to those in the nonsmoker ambient exposure group. PAH-DNA and nicotine/cotinine values were not correlated with birth weight of the infant. PAH-DNA adducts were present in approximately 25% of samples exposed to passive cigarette smoke and ambient environment.

CONCLUSIONS

The study has revealed that a subpopulation of humans is predisposed to accumulating PAH adducts independent of high levels of PAH sources (e.g., maternal cigarette smoke exposure). Because DNA adducts promote genomic changes, it is likely that this subpopulation is susceptible to diverse changes in the genome that may influence human development.

Population level policy options for increasing the prevalence of smokefree homes

OBJECTIVE

To identify and evaluate the options for population level government policies to increase the prevalence of homes free of secondhand smoke.

METHODS

The literature was searched for population level policy options and evidence on them. Three criteria were used to evaluate the policy options: effectiveness, the reductions on inequalities in secondhand smoke exposure, and cost effectiveness. The setting was four developed, English speaking jurisdictions: Britain, USA, Australia, and New Zealand.

RESULTS

Evidence from all four countries shows some association between relatively comprehensive tobacco control programmes and lower prevalence levels of smoking in homes. The evidence of the effect of such programmes on inequalities in smokefree home prevalence is limited. No published evidence was found of the cost effectiveness of the programmes in achieving changes in smokefree homes. Within comprehensive programmes, there is some indirect evidence that some mass media campaigns could increase the prevalence of smokefree homes. Structural options that have potential to support smokefree homes include smokefree places legislation, and laws for the protection of children.

CONCLUSION

The available evidence to date suggests that comprehensive tobacco control programmes (to reduce the prevalence of smoking in the total population) are likely to be the most effective and sustainable option for increasing the prevalence of smokefree homes.

Reduction in the incidence of acute myocardial infarction associated with a citywide smoking ordinance

BACKGROUND

Secondhand smoke exposure increases the risk of acute myocardial infarction (AMI). One study (Helena, Mont) examined the issue and found a decrease in AMI associated with a smoke-free ordinance. We sought to determine the impact of a smoke-free ordinance on AMI admission rates in another geographically isolated community (Pueblo, Colo).

METHODS AND RESULTS

We assessed AMI hospitalizations in Pueblo during a 3-year period, 1.5 years before and 1.5 years after implementation of a smoke-free ordinance. We compared the AMI hospitalization rates among individuals residing within city limits, the area where the ordinance applied, versus those outside city limits. We also compared AMI rates during this time period with another geographically isolated but proximal community, El Paso County, Colo, that did not have an ordinance. A total of 855 patients were hospitalized with a diagnosis of primary AMI in Pueblo between January 1, 2002, and December 31, 2004. A reduction in AMI hospitalizations was observed in the period after the ordinance among Pueblo city limit residents (relative risk [RR]=0.73, 95% confidence interval [CI] 0.63 to 0.85). No significant changes in AMI rates were observed among residents outside city limits (RR=0.85, 95% CI 0.63 to 1.16) or in El Paso County during the same period (RR=0.97, 95% CI 0.89 to 1.06). The reduction in AMI rate within Pueblo differed significantly from changes in the external control group (El Paso County) even after adjustment for seasonal trends (P<0.001).

CONCLUSIONS

A public ordinance reducing exposure to secondhand smoke was associated with a decrease in AMI hospitalizations in Pueblo, Colo, which supports previous data from a smaller study.

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

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

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.

A cross country comparison of exposure to secondhand smoke among youth

Secondhand smoke or environmental tobacco smoke is a combination of smoke from a burning cigarette and exhaled smoke from a smoker. This substance is an involuntarily inhaled mix of compounds that causes or contributes to a wide range of adverse health effects, including cancer, cardiovascular diseases, respiratory infections, adverse reproductive effects, and asthma. This paper presents findings from Global Youth Tobacco Surveys (GYTS) conducted in 132 countries between 1999 and 2005. GYTS data indicate that a large proportion of students in every World Health Organization Region are exposed to secondhand smoke at home (43.9%) and in public places (55.8%), and many have parents (46.5%) or best friends who smoke (17.9%). GYTS data have shown widespread and strong support among students for bans on smoking in public areas all over the world (76.1%). Countries should engage this positive public health attitude among youth to promote and enforce policies for smoke-free public places and workplaces, including restaurants and bars.

Correlating atmospheric and biological markers in studies of secondhand tobacco smoke exposure and dose in children and adults

OBJECTIVE

We sought to directly compare secondhand smoke (SHS) atmospheric markers to each other and to SHS dosimetric biomarkers, permitting intercomparison of clinical and atmospheric studies.

METHODS

We used atmospheric and pharmacokinetic (PK) models for the quantitative estimation of SHS exposure and dose for infants, children, and adults, based on building smoker density and air exchange rate, and from exposure duration, default PK parameters, and respiration rates.

RESULTS

We estimate the SHS serum cotinine doses for the typical and most-exposed individuals in the U.S. population; predictions compare well to measurements on a national probability sample. Using default respiration rates, we estimate serum cotinine dose from SHS nicotine exposure for 40 adults exposed to SHS in an environmental chamber; predictions agreed with observations. We correlate urine cotinine and hair nicotine levels for 127 infants exposed to parental smoking, and estimate corresponding atmospheric nicotine exposure via PK modeling.

CONCLUSIONS

Our "Rosetta Stone" Equations allow the SHS atmospheric markers, respirable particles, nicotine, and carbon monoxide, to be related to the SHS biomarkers, cotinine in blood, urine, and saliva and nicotine in hair, permitting intercomparison of clinical and atmospheric studies of SHS for the first time.

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.

The association of cigarette smoking with self-reported disease before middle age: the Coronary Artery Risk Development in Young Adults (CARDIA) study

BACKGROUND

Evidence that demonstrates the harmful effect of cigarette smoking during young adulthood is limited. Therefore, we assessed associations between cigarette smoking and several self-reported illnesses in a prospective cohort study in healthy young adults.

METHODS

Data were derived from 4472 adults aged 18 to 30 years at baseline participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study and reexamined at least once after 7, 10, or 15 years.

RESULTS

Cigarette smoking in 1985-86 was related to self-reported smoking-related cancers, circulatory disease, and peptic ulcer. Incidence of these diseases was 9.3/1000 person years among current smokers vs. 4.5/1000 person years among never smokers with no exposure to passive smoke, relative risk (adjusted for race, sex, education, and center) 1.96 (1.42-2.70). Assuming causal relationships, 32% of these premature incidents were attributable to smoking. The relative risks of liver disease, migraine headache, depression, being ill the day before the examination, and chronic cough and phlegm production were also higher in smokers.

CONCLUSIONS

Smokers aged 18-30 followed for 7 to 15 years reported an excess of both major and minor ailments related to earlier and current smoking. Thus, prevention, cessation, and avoiding passive smoking should remain strong goals among young people.

Risks for Heart Disease and Lung Cancer from Passive Smoking by Workers in the Catering Industry

Workers in the catering industry are at greater risk of exposure to secondhand smoke (SHS) when smoke-free workplace policies are not in force. We determined the exposure of catering workers to SHS in Hong Kong and their risk of death from heart disease and lung cancer. Nonsmoking catering workers were provided with screening at their workplaces and at a central clinic. Participants reported workplace, home, and leisure time exposure to SHS. Urinary cotinine was estimated by enzyme immunoassay. Catering facilities were classified into three types: nonsmoking, partially restricted smoking (with nonsmoking areas), and unrestricted smoking. Mean urinary cotinine levels ranged from 3.3 ng/ml in a control group of 16 university staff through 6.4 ng/ml (nonsmoking), 6.1 ng/ml (partially restricted), and 15.9 ng/ml (unrestricted smoking) in 104 workers who had no exposures outside of work. Workers in nonsmoking facilities had exposures to other smoking staff. We modeled workers' mortality risks using average cotinine levels, estimates of workplace respirable particulates, risk data for cancer and heart disease from cohort studies, and national (US) and regional (Hong Kong) mortality for heart disease and lung cancer. We estimated that deaths in the Hong Kong catering workforce of 200,000 occur at the rate of 150 per year for a 40-year working-lifetime exposure to SHS. When compared with the current outdoor air quality standards for particulates in Hong Kong, 30% of workers exceeded the 24-h and 98% exceeded the annual air quality objectives due to workplace SHS exposures.

Secondhand smoke exposure and risk following the Irish smoking ban: an assessment of salivary cotinine concentrations in hotel workers and air nicotine levels in bars

OBJECTIVE

To investigate whether the Irish smoking ban has had an impact on secondhand smoke (SHS) exposures for hospitality workers.

DESIGN, SETTING, AND PARTICIPANTS

Before and after the smoking ban a cohort of workers (n = 35) from a sample of city hotels (n = 15) were tested for saliva cotinine concentrations and completed questionnaires. Additionally, a random sample (n = 20) of city centre bars stratified by size (range 400-5000 square feet), were tested for air nicotine concentrations using passive samplers before and after the ban.

MAIN OUTCOME MEASURES

Salivary cotinine concentrations (ng/ml), duration of self reported exposures to secondhand smoke, air nicotine (microg/cubic metre).

RESULTS

Cotinine concentrations reduced by 69%, from 1.6 ng/ml to 0.5 ng/ml median (SD 1.29; p < 0.005). Overall 74% of subjects experienced decreases (range 16-99%), with 60% showing a halving of exposure levels at follow up. Self reported exposure to SHS at work showed a significant reduction from a median 30 hours a week to zero (p < 0.001). There was an 83% reduction in air nicotine concentrations from median 35.5 microg/m3 to 5.95 microg/m3 (p < 0.001). At baseline, three bars (16%) were below the 6.8 microg/m3 air nicotine significant risk level for lung cancer alone; at follow up this increased to 10 (53%).

CONCLUSIONS

Passive smoking and associated risks were significantly reduced but not totally eliminated. Exposure to SHS is still possible for those working where smoking is still allowed and those working where smoke may migrate from outdoor areas. Further research is required to assess the true extent and magnitude of these exposures.

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.

Short-term impact of smoking cessation on myocardial infarction and stroke hospitalisations and costs in Australia

OBJECTIVE

To estimate the short-term benefits of a reduction in smoking on acute myocardial infarction (AMI) and stroke hospitalisations and costs.

DESIGN AND SETTING

Epidemiological study which applied functions describing reductions over time in risk of AMI and stroke in people quitting smoking to hospitalisation rates and costs for Australia.

MAIN OUTCOME MEASURES

The numbers of AMI and stroke hospitalisations in 35-64-year-olds and the associated costs that could have been avoided over a 7-year period from 2001-02 if smoking prevalence had decreased by 1% in the first year (Scenario 1) or by 1% per annum for 5 consecutive years (Scenario 2).

RESULTS

Under Scenario 1, almost 1000 hospitalisations for AMI and about 350 hospitalisations for stroke would have been avoided over 7 years, saving about $20.4 million in health care costs. Under Scenario 2, over 3000 AMI hospitalisations and over 1000 stroke hospitalisations would be avoided, and health care costs could be reduced by $61.6 million (2.75% of costs for AMI and stroke over the period).

CONCLUSIONS

This study provides further support for the proposition that modest and achievable reductions in smoking rates can substantially improve health outcomes and reduce health care costs, even in the short term.

Dietary vitamin C down-regulates inflammatory gene expression in apoE4 smokers

The deleterious impact of cigarette smoking on cardiovascular health may be in part attributable to a free radical mediated proinflammatory response in circulating monocytes. In the current investigation, the impact of vitamin C supplementation on monocyte gene expression was determined in apoE4 smokers versus non-smokers. A total of 10 smokers and 11 non-smokers consumed 60mg/day of vitamin C for four weeks and a fasting blood sample was taken at baseline and post-intervention for the determination of plasma vitamin C and monocyte gene expression profiles using cDNA array and real time PCR. In apoE4 smokers, supplementation resulted in a 43% increase in plasma vitamin C concentrations. Furthermore, a number of genes were differentially expressed more than 2-fold in response to treatment, including a downregulation of the proinflammatory mediators tumor necrosis factor (TNF) beta, TNF receptor, neurotrophin-3 growth factor receptor, and monocyte chemoattractant protein 1 receptor. The study has identified a number of molecular mechanisms underlying the benefit of vitamin C supplementation in smokers.

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.

Tobacco Smoke Exposure Is Associated With the Metabolic Syndrome in Adolescents

Background— The metabolic syndrome predicts future coronary artery disease and type II diabetes and often emerges in childhood. Tobacco smoke potentially contributes to insulin resistance in this syndrome. This study evaluates the association of environmental tobacco smoke (ETS) exposure and active smoking with the prevalence of the metabolic syndrome in US adolescents.

Methods and Results— Data from 2273 subjects 12 to 19 years of age were examined from the National Health and Nutrition Examination Survey III (NHANES III, 1988 to 1994). Serum cotinine levels, presence of household smokers, and self-report of smoking were used to determine ETS exposure and active smoking. The metabolic syndrome was defined as having ≥3 criteria from the National Cholesterol Education Panel definition. Bivariate and multivariable analyses were conducted. Among adolescents, 5.6% met the criteria for metabolic syndrome, and prevalence increased with tobacco exposure: 1.2% for nonexposed, 5.4% for those exposed to ETS, and 8.7% for active smokers ( P <0.001). In adolescents at risk for overweight and overweight adolescents (body mass index above the 85th percentile), a similar relationship was observed: 5.6% for nonexposed, 19.6% for those exposed to ETS, and 23.6% for active smokers ( P =0.01). In multivariable logistic regression analyses among all adolescents, ETS exposure was independently associated with the metabolic syndrome (ETS exposure: odds ratio, 4.7, 95% CI, 1.7 to 12.9; active smoking: odds ratio, 6.1; 95% CI, 2.8 to 13.4).

Conclusions— Considering that tobacco and obesity are the 2 leading causes of preventable death in the United States, these findings of a dose-response, cotinine-confirmed relationship between tobacco smoke and metabolic syndrome among adolescents may have profound implications for the future health of the public.

Atherosclerosis in childhood and adolescent type 1 diabetes: early disease, early treatment?

Autopsy studies have shown that atherosclerosis begins in adolescence in otherwise healthy individuals, and imaging techniques have shown that atherosclerosis develops earlier and is more prevalent in children with diabetes than in age-matched healthy controls. Cardiovascular disease has now overtaken diabetic nephropathy as the leading cause of premature mortality in young adults with diabetes, and the emphasis on disease prevention has accordingly shifted to a younger age group. The majority of children and adolescents with diabetes have suboptimal blood glucose control, and this contributes to accelerated arterial disease in this age group. Other conventional risk factors for coronary heart disease also need to be considered and treated aggressively. Effective early prevention of cardiovascular disease will involve lifestyle modification and full implementation of existing treatment guidelines, and large-scale prospective studies will be needed to establish the risks and benefits of early pharmacological intervention in children and adolescents.

Carboxyhaemoglobin concentration, smoking habit, and mortality in 25 years in the Renfrew/Paisley prospective cohort study

OBJECTIVE

To investigate how carboxyhaemoglobin concentration is related to smoking habit and to assess whether carboxyhaemoglobin concentration is related to mortality.

DESIGN

Prospective cohort study.

SETTING

Residents of the towns of Renfrew and Paisley in Scotland.

PARTICIPANTS

The whole Renfrew/Paisley study, conducted between 1972 and 1976, consisted of 7048 men and 8354 women aged 45-64 years. This study was based on 3372 men and 4192 women who were screened after the measurement of carboxyhaemoglobin concentration was introduced about halfway through the study.

MAIN OUTCOME MEASURES

Deaths from coronary heart disease (CHD), stroke, chronic obstructive pulmonary disease (COPD), lung cancer, and all causes in 25 years after screening.

RESULTS

Carboxyhaemoglobin concentration was related to self reported smoking and for each smoking category was higher in participants who reported inhaling than in those who reported not inhaling. Carboxyhaemoglobin concentration was positively related to all causes of mortality analysed (relative rates associated with a 1 SD (2.93) increase in carboxyhaemoglobin for all causes, CHD, stroke, COPD, and lung cancer were 1.26 (95% confidence interval (CI) 1.19 to 1.34), 1.19 (95% CI 1.13 to 1.26), 1.19 (95% CI 1.13 to 1.26), 1.64 (95% CI 1.47 to 1.84), and 1.69 (95% CI 1.60 to 1.79), respectively). Adjustment for self reported cigarette smoking attenuated the associations but they remained relatively strong.

CONCLUSIONS

Self reported smoking data were validated by the objective measure of carboxyhaemoglobin concentration. Since carboxyhaemoglobin concentration remained associated with mortality after adjustment for smoking, carboxyhaemoglobin seems to capture more of the risk associated with smoking tobacco than does self reported tobacco consumption alone. Analysing mortality by self reported cigarette smoking underestimates the strength of association between smoking and mortality.

Estimate of deaths attributable to passive smoking among UK adults: database analysis

OBJECTIVE

To estimate deaths from passive smoking in employees of the hospitality industry as well as in the general workforce and general population of the United Kingdom.

DESIGN

Calculation, using the formula for population attributable proportion, of deaths likely to have been caused by passive smoking at home and at work in the UK according to occupation. Sensitivity analyses to examine impact of varying assumptions regarding prevalence and risks of exposure.

SETTING

National UK databases of causes of death, employment, structure of households, and prevalences of active and passive smoking.

MAIN OUTCOME MEASURES

Estimates of deaths due to passive smoking according to age group (< 65 or > or = 65) and site of exposure (domestic or workplace).

RESULTS

Across the United Kingdom as a whole, passive smoking at work is likely to be responsible for the deaths of more than two employed people per working day (617 deaths per year), including 54 deaths in the hospitality industry each year. Each year passive smoking at home might account for another 2700 deaths in persons aged 20-64 years and 8000 deaths among people aged > or = 65.

CONCLUSION

Exposure at work might contribute up to one fifth of all deaths from passive smoking in the general population aged 20-64 years, and up to half of such deaths among employees of the hospitality industry. Adoption of smoke free policies in all workplaces and reductions in the general prevalence of active smoking would lead to substantial reductions in these avoidable deaths.

Lifestyle and cardiovascular disease in middle-aged British men: the effect of adjusting for within-person variation

AIMS

To examine the effect that within-person variation has on the estimated risk associations between cigarette smoking, physical inactivity, and increased body mass index (BMI) and the development of cardiovascular disease (CVD) in middle-aged British men.

METHODS AND RESULTS

In total, 6452 men aged 40-59 with no prior evidence of CVD were followed for major CVD events (fatal/non-fatal myocardial infarction or stroke) and all-cause mortality over 20 years; lifestyle characteristics were ascertained at regular points throughout the study. A major CVD event within the first 20 years was observed in 1194 men (18.5%). Use of baseline assessments of cigarette smoking and physical activity in analyses resulted in underestimation of the associations between average cumulative exposure to these factors and major CVD risk. After correction for within-person variation, major CVD rates were over four times higher for heavy smokers (> or =40 cigarettes/day) compared with never smokers and three times higher for physically inactive men compared with moderately active men. Major CVD risk increased by 6% for each 1 kg/m(2) increase in usual BMI. If all men had experienced the risk levels of the men who had never regularly smoked cigarettes, were moderately active, and had a BMI of < or =25 kg/m(2) (6% of the population), 66% of the observed major CVD events would have been prevented or postponed (63% before adjustment for within-person variation). Adjustment for a range of other risk factors had little effect on the results. Similar results were obtained for all-cause mortality.

CONCLUSION

Failure to take account of within-person variation can lead to underestimation of the importance of lifestyle characteristics in determining CVD risk. Primary prevention through lifestyle modification has a great preventive potential.

Deteriorative Effect of Smoking on Target Lesion Revascularization After Implantation of Coronary Stents With Diameter of 3.0 mm or Less

BACKGROUND

Although smoking cessation is widely encouraged because of the associated risk of cardiovascular events, the impact of smoking on target lesion revascularization (TLR) after percutaneous coronary intervention (PCI) is controversial. Therefore, the present study retrospectively investigated the effect of smoking on TLR after plain-old balloon angioplasty (POBA; n=376) and stenting (STENT; n=434) in patients undergoing secondary coronary angiography at a single center.

METHODS AND RESULTS

A smoker was defined as current smoking or quitting within 2 years of the first PCI. In the POBA group, the predictors for TLR, as calculated by multiple logistic regression analysis, were a complex type of lesion (p<0.0001) and the left anterior descending artery (LAD) as affected vessel (p<0.05). In the STENT group, the predictors were the final % diameter of stenosis after stenting, measured by quantitative coronary arteriography (p<0.0005), LAD (p<0.01), and smoking (p=0.049). When the STENT group was divided into 2 groups according to the diameter of the implanted stent, smoking was a predictive factors for TLR in the group that received relatively small stents (diameter < or =3.0 mm) (p<0.02), but not in the group that received larger stents (diameter > or =3.5 mm).

CONCLUSION

Smoking has a deteriorative effect on TLR after implantation of relatively small coronary stents with a diameter of 3.0 mm or less.