Epidemiologic studies of fatal and nonfatal cardiovascular disease and ETS exposure from spousal smoking

The association between smoking or passive smoking and cardiovascular diseases using a Bayesian hierarchical model: based on the 2008-2013 Korea Community Health Survey

OBJECTIVES

Smoking and passive smoking have been extensively reported as risk factors of cardiovascular morbidity and mortality. Despite the biological mechanisms underlying the impact of hazardous chemical substances contained in tobacco in cardiovascular diseases (CVD), studies investigating the association between smoking and passive smoking with morbidity are at an inchoate stage in Korea. Therefore, this study aimed to estimate the risks of smoking and passive smoking on cardiovascular morbidity at the national and regional levels.

METHODS

This study calculated sex-standardized and age-standardized prevalence of CVD and smoking indices in 253 community health centers (si/gun/gu) in Korea using the 2008-2013 Korea Community Health Survey data. Furthermore, a Bayesian hierarchical model was used to estimate the association of smoking and passive smoking with the prevalence of CVD from the national and regional community health centers.

RESULTS

At the national level, smoking was significantly associated with stroke (relative risk [RR], 1.060) and hypertension (RR, 1.016) prevalence, whilst passive smoking at home and work were also significantly associated with prevalence of stroke (RR, 1.037/1.013), angina (RR, 1.016/1.006), and hypertension (RR, 1.010/1.004). Furthermore, the effects of smoking and passive smoking were greater in urban-industrial areas than in rural areas.

CONCLUSIONS

The findings of this study would provide grounds for national policies that limit smoking and passive smoking, as well as regionally serve as the basis for region-specific healthcare policies in populations with high CVD vulnerability.

Modeling lifetime costs and health outcomes attributable to secondhand smoke exposure at home among Korean adult women

PURPOSE

The aim of this research is to estimate lifetime costs and health consequences for Korean adult women who were exposed to secondhand smoke (SHS) at home.

METHODS

A Markov model was developed to project the lifetime healthcare costs and health outcomes of a hypothetical cohort of Korean women who are 40 years old and were married to current smokers. The Korean epidemiological data were used to reflect the natural history of SHS-exposed and non-exposed women. The direct healthcare costs (in 2014 US dollars) and quality-adjusted life years (QALYs) were annually discounted at 5% to reflect time preference. The time horizon of the analysis was lifetime and the cycle length was 1 year. Deterministic and probabilistic sensitivity analyses were conducted.

RESULTS

In the absence of SHS exposure, Korean women will live 41.32 years or 34.56 QALYs before discount, which corresponded to 17.29 years or 15.35 QALYs after discount. The SHS-exposed women were predicted to live 37.91 years and 31.08 QALYs before discount and 16.76 years and 14.62 QALYs after discount. The estimated lifetime healthcare cost per woman in the SHS non-exposed group was US$11 214 before the discount and US$2465 after discount. The negative impact of SHS exposure on health outcomes and healthcare costs escalated as the time horizon increased, suggesting that the adverse impact of SHS exposure may have higher impact on the later part of the lifetime. The result was consistent across a wide range of assumptions.

CONCLUSION

Life expectancy might underestimate the impact of SHS exposure on health outcomes, especially if the time horizon of the analysis is not long enough. Early intervention on smoking behaviour could substantially reduce direct healthcare costs and improve quality of life attributable to SHS exposure.

[ETAP: A smoking scale for Primary Health Care]

OBJECTIVE

To obtain a scale of tobacco exposure to address smoking cessation.

DESIGN

Follow-up of a cohort. Scale validation.

SETTING

Primary Care Research Unit. Tenerife.

PARTICIPANTS

A total of 6729 participants from the "CDC de Canarias" cohort.

METHODS

A scale was constructed under the assumption that the time of exposure to tobacco is the key factor to express accumulated risk. Discriminant validity was tested on prevalent cases of acute myocardial infarction (AMI; n=171), and its best cut-off for preventive screening was obtained. Its predictive validity was tested with incident cases of AMI (n=46), comparing the predictive power with markers (age, sex) and classic risk factors of AMI (hypertension, diabetes, dyslipidaemia), including the pack-years index (PYI).

RESULTS

The scale obtained was the sum of three times the years that they had smoked plus years exposed to smoking at home and at work. The frequency of AMI increased with the values of the scale, with the value 20 years of exposure being the most appropriate cut-off for preventive action, as it provided adequate predictive values for incident AMI. The scale surpassed PYI in predicting AMI, and competed with the known markers and risk factors.

CONCLUSION

The proposed scale allows a valid measurement of exposure to smoking and provides a useful and simple approach that can help promote a willingness to change, as well as prevention. It still needs to demonstrate its validity, taking as reference other problems associated with smoking.

Meta-analysis of the association between second-hand smoke exposure and ischaemic heart diseases, COPD and stroke

Background

Second-hand smoke (SHS) is the most important contaminant of indoor air in first world countries. The risks associated with SHS exposure are highly relevant, because many people are regularly, and usually involuntarily, exposed to SHS. This study aims to quantify the effects of SHS exposure. Therefore, its impact on ischaemic heart diseases (IHD), chronic obstructive pulmonary diseases (COPD) and stroke will be considered.

Methods

A systematic literature review was conducted to identify articles dealing with the association between SHS and the three outcomes IHD, COPD and stroke. Overall, 24 articles were included in a meta-analysis using a random effects model. Effect sizes stratified for sex and for both sexes combined were calculated.

Results

The synthesis of primary studies revealed significant effect sizes for the association between SHS exposure and all three outcomes. The highest RR for both sexes combined was found for COPD (RR = 1.66, 95 % CI: 1.38–2.00). The RR for both sexes combined was 1.35 (95 % CI: 1.22–1.50) for stroke and 1.27 (95 % CI: 1.10–1.48) for IHD. The risks were higher in women than in men for all three outcomes.

Conclusions

This is the first study to calculate effect sizes for the association between SHS exposure and the disease outcomes IHD, COPD, and stroke at once. Overall, the effect sizes are comparable with previous findings in meta-analyses and therefore assumed to be reliable. The results indicate the high relevance of public health campaigns and legislation to protect non-smokers from the adverse health effects attributable to SHS exposure.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-2489-4) contains supplementary material, which is available to authorized users.

Risk of all-cause mortality and cardiovascular disease associated with secondhand smoke exposure: a systematic review and meta-analysis

BACKGROUND

Emerging studies have assessed the association between secondhand smoke (SHS) exposure and cardiovascular disease (CVD) as well as all-cause mortality. However, findings were not consistent due to the heterogeneity of study characteristics.

METHODS

PubMed and Embase were searched through May 2014 for prospective cohort and case-control studies investigating the associations of SHS exposure in never smokers with all-cause mortality and the risk of CVD. The main analysis was performed in studies using self-reported SHS exposure and secondary analysis was performed in studies using objectively measured SHS exposure. Summary estimates were calculated using random-effects models.

RESULTS

Twenty-three prospective and 17 case-control studies were included. The pooled relative risks (RR) for never smokers exposed to SHS in comparison with those unexposed were 1.18 [95% confidence interval (CI): 1.10-1.27] for all-cause mortality (12 studies), and 1.23 (1.16-1.31) for CVD (38 studies). The association of SHS exposure with CVD was markedly stronger among studies conducted in China (RR=1.65, 95% CI 1.27-2.13) than that in the US (RR=1.09, 95% CI 1.03-1.16). Studies using objectively measured SHS exposure demonstrated a slightly higher risk for CVD compared with those using self-reported SHS exposure.

CONCLUSIONS

Exposure to SHS significantly increased the risk for all-cause mortality and CVD. The risk associated with SHS exposure was large in China while the risk was only modest in the US. Studies using objectively measured SHS exposure may yield a higher risk of CVD than those using self-reported SHS exposure.

Second-hand Smoking and CV Risk

OPINION STATEMENT

Issues related to passive smoking have recently been addressed in the specialty literature, and they are particularly relevant from two perspectives: the effects on health and implications in the initiation of smoking among youth. The mechanisms by which tobacco smoke is involved in the pathology of heart disease are numerous, and are based not on a single action, but involve multiple factors. The effects of "second-hand" smoking on the cardiovascular system are evident in cardiovascular disease biomarkers seen in nonsmokers and the increased risk of mortality. In 2003, the World Health Assembly adopted the Framework Convention on Tobacco Control (FCTC), which was negotiated under the auspices of the World Health Organization (WHO) and is an evidence-based treaty promulgated with the intent of implementing effective policies for tobacco control. The effects of such policies have been documented in numerous studies. For example, the number of ER patients presenting with acute coronary events (myocardial infarction) has decreased 27-40 % in the U.S., 13 % in Italy, and 17 % in Scotland. The harmful consequences of passive smoking in cardiovascular and other organ systems must be confronted across the medical community. Cardiologists should unite with other specialists to encourage concerted legal action, economic measures, and public education as we work toward the tobacco endgame.

Epidemiology and public health policy of tobacco use and cardiovascular disorders in low- and middle-income countries

All forms of tobacco lead to an increased risk of cardiovascular disorders. During the past few decades, the number of people who consume tobacco has increased worldwide because of an overall increase in the global population. It is estimated that close to 80% of the >1.3 billion people who smoke tobacco in the world are in low- and middle-income countries. Smokeless forms of tobacco are also widely consumed in low- and middle-income countries, including chewable and snuffed forms. Lack of targeted and effective strategies to control tobacco consumption contributes to a large burden of cardiovascular disorders in low- and middle-income countries, where cardiovascular disorders have become the leading cause of morbidity and mortality. In this review, we evaluate the epidemiology of tobacco use in low- and middle-income countries and assess the public health policies needed to control tobacco use in such regions for the prevention of cardiovascular disorders and other tobacco-related morbidities and mortality.

Microfluidic immunoassay for rapid detection of cotinine in saliva

A microfluidic immunoassay is successfully developed for rapid analysis of cotinine saliva samples, which is a metabolite of nicotine and is widely used as a biomarker to evaluate the smoking status and exposure to tobacco smoke. The core microfluidic chip is fabricated by polydimethylsiloxane (PDMS) with standard soft lithography. Each chip is capable of eight parallel analyses of cotinine samples. The analyses can be completed within 40 min with 12 μl sample consumption. The linear detection range is 1 ~ 250 ng/ml and the minimum detectable concentration is 1 ng/ml respectively. The correlation coefficient of the calibration curve established from standard samples is 0.9989. The immunoassay was also validated by real saliva samples, and the results showed good reproducibility and accuracy. All the results were confirmed with traditional ELISA measurements. The result from microfluidic chip device and ELISA kits showed good correspondence, and the correlation coefficients are higher than 0.99. Compared with traditional technique, this microfluidic immunoassay is more economic, rapid, simple and sensitive, perfect for on-site cotinine measurements as well as for the evaluation of the exposure to tobacco smoking. Moreover, this immunoassay has potential to be applied in the analysis of other biomarkers in human saliva samples.

Indoor air quality in a bar/restaurant before and after the smoking ban in Athens, Greece

In this study we compared indoor air pollutant concentrations in a bar/restaurant in Greece before and after the enactment of a smoking ban legislation of 2008. This was done to investigate whether the separation of the venue into smoking and non-smoking areas will have an impact on workers and customers from secondhand smoke (SHS) exposure (null hypothesis). The study was completed within an 8-month period beginning in March 2010 and ending on November 2010. We compared the average of the measured PM0.1 concentrations in the smoking zones between the pre-ban and post-ban periods. Overall reduction in the number of particles was 18% between pre-ban and post-ban periods. The mean of the 36 total CO2 measurements for the pre- and the post-ban period was 611ppm. We calculated the ventilation rates per occupant (Vo in l/s/occ) and found it to be higher in the post-ban period (19.4l/s/occ), thus complying with the ASHARAE standard for Vo of 15l/s/occ at maximum occupancy, than in the pre-ban period (10.7l/s/occ). The mean of the 36 total CO measurements for the pre-ban period was 2 ppm. CO measurements in the post-ban period were less than the detection limit of 1 ppm. Emissions of nitrogen dioxide and formaldehyde weren't detected in any of the zones. It was observed there was about 50% distribution of pollutants from the smoking zones to the smoke-free zones. The smoking ban effect on the occupancy levels was initially reduced by 16%, but based on other similar studies this transition period will be followed by an increase in the occupancy. Passive smoking and associated risks were significantly reduced but not totally eliminated, indicating the need for stronger enforcement or complete partition between smoking and non-smoking areas.

Mortality risks associated with environmental tobacco smoke exposure in the United States

INTRODUCTION

Researchers have presented various estimates of mortality attributable to environmental tobacco smoke (ETS) exposure in the United States, but mortality risk estimates for ETS exposure from U.S. health survey data are generally unavailable.

METHODS

I estimated mortality hazard ratios (HRs) for ETS exposure from Third National Health and Nutrition Examination Survey (NHANES III) data from 1988 to 1994 linked for 4 and 8 years of mortality follow-up. I classified ETS exposure based on observed serum cotinine concentrations (low ETS exposure: <0.1 ng/ml, medium ETS exposure: ≥ 0.1 ng/ml, and <1 ng/ml, and high ETS exposure: ≥ 1 ng/ml and <15 ng/ml) and reported home ETS exposure information. I also estimated ETS exposure among U.S. nonsmokers over time using NHANES III data and continuous NHANES data from 1999 to 2010.

RESULTS

High ETS exposure was associated with higher ischemic heart disease mortality risk (HR = 2.47, 95% CI = 1.04-5.86) among never-smokers during 4 years of follow-up, adjusting for age, sex, race/ethnicity, educational attainment, alcohol consumption, body mass index, high blood pressure, and serious circulatory conditions. The prevalence of medium ETS exposure among nonsmokers decreased from 53.0% (95% CI = 51.5%-54.5%) in NHANES III to 16.7% (95% CI = 15.3%-18.1%) in NHANES from 2005 to 2010.

CONCLUSIONS

I found an association between high ETS exposure and heart disease mortality risk among never-smokers during short-term mortality follow-up using U.S. national health survey data. I also found that ETS exposure among U.S. nonsmokers has substantially decreased in recent decades.

Changes in environmental tobacco smoke exposure: the Beaver Dam experience

OBJECTIVES

Environmental tobacco smoke (ETS) exposure has been associated with adverse health outcomes. Our goal was to determine if ETS exposure changed between 1998-2000 and 2003-2005 among participants in the population-based Epidemiology of Hearing Loss Study.

METHODS

ETS exposure was ascertained using a cotinine-validated questionnaire at the 5-year (1998-2000) and 10-year follow-up examinations (2003-2005). Non-smoking participants with data from both visits were included (n=1898; ages 53-96 years at 5-yr follow-up). McNemar's test was used to test differences in ETS exposure overall and in 3 settings: home, work, and social settings. Generalized estimating equations (GEE) were used for multivariate logistic regression models of exposure.

RESULTS

The proportion of nonsmokers with no or little ETS exposure increased from 80% to 88% (P< 0.0001). The percent living in a home with no indoor smokers increased from 94% to 97% (P<0.0001). The percent reporting no exposure at work increased from 91% to 95% (P<0.0001). The percent reporting the lowest frequency of social exposure increased from 65% to 77% (P<0.0001). In the GEE model, age was inversely associated with overall ETS exposure (Odds Ratio [OR] per 5 yr= 0.87, 95% CI= 0.81, 0.94), as was education (OR for college vs < high school=0.25, 95% CI=0.16, 0.37), female gender (ORI= 0.41, 95% CI= 0.33, 0.51), and later examination period (OR =0.62, 95% CI= 0.53, 0.73); current employment was positively associated with exposure (OR=1.44, 95% CI=1.14, 1.83).

CONCLUSIONS

Between the late 1990s and the mid-2000s, ETS exposure in older adults decreased. Decreasing exposures suggest there may be future declines in ETS-related adverse health outcomes.

Cigarette smoking associated with lung adenocarcinoma in situ in a large case-control study (SFBALCS)

INTRODUCTION

Adenocarcinoma in situ (AIS), formerly bronchioloalveolar carcinoma, is an uncommon subtype of lung adenocarcinoma and accounts for approximately 3% to 4% of lung cancers. Compared with other lung cancer histologies, AIS patients are less likely to be smokers, yet associations with other lung cancer risk factors and differences by sex have not been determined.

METHODS

A total of 338 AIS patients and frequency-matched controls from the parent study (cases = 6039, controls = 2073) were included in these analyses. Odds ratios and 95% confidence intervals as estimates of the relative risk were obtained from multivariable unconditional logistic regression analyses.

RESULTS

Risk of AIS was associated with ever smoking (OR = 2.7, 95% confidence intervals: 2.1, 3.6), increased 20% to 30% for each 10-year increase in pack-years of smoking and decreased with increased years since quitting (p for trend <0.0001). There was no evidence that risk differed by sex but there was some suggestion that risk may differ by exposure to asbestos and by second-hand tobacco smoke exposure in whites.

CONCLUSION

There is an association between AIS and smoking, which is smaller in magnitude than the association between other subtypes of non-small-cell lung cancer and smoking. Our findings suggesting that effects may differ by exposure to asbestos and second-hand tobacco smoke should be interpreted conservatively and warrant validation and further evaluation in larger studies of AIS.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Intervention to lower household wood smoke exposure in Guatemala reduces ST-segment depression on electrocardiograms

BACKGROUND

A large body of evidence suggests that fine particulate matter (PM) air pollution is a cause of cardiovascular disease, but little is known in particular about the cardiovascular effects of indoor air pollution from household use of solid fuels in developing countries. RESPIRE (Randomized Exposure Study of Pollution Indoors and Respiratory Effects) was a randomized trial of a chimney woodstove that reduces wood smoke exposure.

OBJECTIVES

We tested the hypotheses that the stove intervention, compared with open fire use, would reduce ST-segment depression and increase heart rate variability (HRV).

METHODS

We used two complementary study designs: a) between-groups comparisons based on randomized stove assignment, and b) before-and-after comparisons within control subjects who used open fires during the trial and received chimney stoves after the trial. Electrocardiogram sessions that lasted 20 hr were repeated up to three times among 49 intervention and 70 control women 38-84 years of age, and 55 control subjects were also assessed after receiving stoves. HRV and ST-segment values were assessed for each 30-min period. ST-segment depression was defined as an average value below -1.00 mm. Personal fine PM [aerodynamic diameter ≤ 2.5 μm (PM₂.₅] exposures were measured for 24 hr before each electrocardiogram.

RESULTS

PM₂.₅ exposure means were 266 and 102 μg/m³ during the trial period in the control and intervention groups, respectively. During the trial, the stove intervention was associated with an odds ratio of 0.26 (95% confidence interval, 0.08-0.90) for ST-segment depression. We found similar associations with the before-and-after comparison. The intervention was not significantly associated with HRV.

CONCLUSIONS

The stove intervention was associated with reduced occurrence of nonspecific ST-segment depression, suggesting that household wood smoke exposures affect ventricular repolarization and potentially cardiovascular health.

Short term impact of smoke-free legislation in England: retrospective analysis of hospital admissions for myocardial infarction

OBJECTIVE

To measure the short term impact on hospital admissions for myocardial infarction of the introduction of smoke-free legislation in England on 1 July 2007.

DESIGN

An interrupted time series design with routinely collected hospital episode statistics data. Analysis of admissions from July 2002 to September 2008 (providing five years' data from before the legislation and 15 months' data from after) using segmented Poisson regression.

SETTING

England. Population All patients aged 18 or older living in England with an emergency admission coded with a primary diagnosis of myocardial infarction.

MAIN OUTCOME MEASURES

Weekly number of completed hospital admissions.

RESULTS

After adjustment for secular and seasonal trends and variation in population size, there was a small but significant reduction in the number of emergency admissions for myocardial infarction after the implementation of smoke-free legislation (-2.4%, 95% confidence interval -4.06% to -0.66%, P=0.007). This equates to 1200 fewer emergency admissions for myocardial infarction (1600 including readmissions) in the first year after legislation. The reduction in admissions was significant in men (3.1%, P=0.001) and women (3.8%, P=0.007) aged 60 and over, and men (3.5%, P<0.01) but not women (2.5% P=0.38) aged under 60.

CONCLUSION

This study adds to a growing body of evidence that smoke-free legislation leads to reductions in myocardial infarctions. It builds on previous work by showing that such declines are observed even when underlying reductions in admissions and potential confounders are controlled for. The considerably smaller decline in admissions observed in England compared with many other jurisdictions probably reflects aspects of the study design and the relatively low levels of exposure to secondhand smoke in England before the legislation.

Public health benefits of strategies to reduce greenhouse-gas emissions: household energy

Energy used in dwellings is an important target for actions to avert climate change. Properly designed and implemented, such actions could have major co-benefits for public health. To investigate, we examined the effect of hypothetical strategies to improve energy efficiency in UK housing stock and to introduce 150 million low-emission household cookstoves in India. Methods similar to those of WHO's Comparative Risk Assessment exercise were applied to assess the effect on health that changes in the indoor environment could have. For UK housing, the magnitude and even direction of the changes in health depended on details of the intervention, but interventions were generally beneficial for health. For a strategy of combined fabric, ventilation, fuel switching, and behavioural changes, we estimated 850 fewer disability-adjusted life-years (DALYs), and a saving of 0.6 megatonnes of carbon dioxide (CO(2)), per million population in 1 year (on the basis of calculations comparing the health of the 2010 population with and without the specified outcome measures). The cookstove programme in India showed substantial benefits for acute lower respiratory infection in children, chronic obstructive pulmonary disease, and ischaemic heart disease. Calculated on a similar basis to the UK case study, the avoided burden of these outcomes was estimated to be 12 500 fewer DALYs and a saving of 0.1-0.2 megatonnes CO(2)-equivalent per million population in 1 year, mostly in short-lived greenhouse pollutants. Household energy interventions have potential for important co-benefits in pursuit of health and climate goals.

Who is exposed to secondhand smoke? Self-reported and serum cotinine measured exposure in the U.S., 1999-2006

This study presents self-reported and serum cotinine measures of exposure to secondhand smoke (SHS) for nonsmoking children, adolescents, and adults. Estimates are disaggregated by time periods and sociodemographic characteristics based on analyses of the 1999-2006 National Health and Nutrition Examination Survey. Self-reported exposure rates are found to be highest for children, followed by adolescents and adults. Important differences in exposure are found by socioeconomic characteristics. Using serum cotinine to measure exposure yields much higher prevalence rates than self-reports. Rates of SHS exposure remain high, but cotinine levels are declining for most groups.

Partner's smoking status and acute coronary syndrome: population-based case-control study in Tirana, Albania

AIM

To assess the association between partners' smoking status and acute coronary syndrome in never smokers in Albania.

METHODS

This population-based case-control study was conducted in Tirana in the period 2003-2006. It involved 467 consecutive patients with non-fatal acute coronary syndrome and 737 controls. Only married never-smokers (169 patients with acute coronary syndrome and 323 controls) were included in the analysis. Information on socioeconomic status, coronary risk factors, and partners' current smoking status was obtained by a structured questionnaire. Multivariate logistic regression was used to assess the association between partner's smoking status and acute coronary syndrome.

RESULTS

Among patients with acute coronary syndrome, 49% of women and 25% of men had a partner who was a current smoker, as opposed to 44% of women and 16% of men in the control group. In age-adjusted models, non-smoking men with smoking partners had a greater acute coronary syndrome risk (odds ratio [OR], 1.76; 95% confidence interval [CI], 0.98-3.18), while no association was found in women with smoking partners (OR, 1.05; 95% CI, 0.48-2.30). After adjustment for socioeconomic characteristics, coronary risk factors, and psychosocial factors, the acute coronary syndrome risk in men was somewhat lower (1.68; 95% CI, 0.81-3.47), while for women it was somewhat greater but still non-significant (1.19; 95% CI, 0.25-5.64). Sex-pooled estimate of the risk was OR 1.64 (95% CI, 0.96-2.83).

CONCLUSION

Partner's current smoking status was positively associated with a greater acute coronary syndrome risk in men but not in women, both before and after adjustment for socioeconomic characteristics and coronary risk factors. Programs aimed at reducing the exposure to passive smoking are need in countries with high prevalence of active smoking.

Short-term secondhand smoke exposure decreases heart rate variability and increases arrhythmia susceptibility in mice

Exposure to secondhand smoke (SHS), a major indoor air pollutant, is linked to increased cardiovascular morbidity and mortality, including cardiac arrhythmias. However, the mechanisms underlying the epidemiological findings are not well understood. Impaired cardiac autonomic function, indexed by reduced heart rate variability (HRV), may represent an underlying cause. The present study takes advantage of well-defined short-term SHS exposure (3 days, 6 h/day) on HRV and the susceptibility to arrhythmia in mice. With the use of electrocardiograph telemetry recordings in conscious mice, HRV parameters in the time domain were measured during the night after each day of exposure and 24 h after 3 days of exposure to either SHS or filtered air. The susceptibility to arrhythmia was determined after 3 days of exposure. Exposure to a low concentration of SHS [total suspended particle (TSP), 2.4 +/- 3.2; and nicotine, 0.3 +/- 0.1 mg/m(3)] had no significant effect on HRV parameters. In contrast, the exposure to a higher but still environmentally relevant concentration of SHS (TSP, 30 +/- 1; and nicotine, 5 +/- 1 mg/m(3)) significantly reduced HRV starting after the first day of exposure and continuing 24 h after the last day of exposure. Moreover, the exposed mice showed a significant increase in ventricular arrhythmia susceptibility and atrioventricular block. The data suggest that SHS exposure decreased HRV beyond the exposure period and was associated with an increase in arrhythmia susceptibility. The data provide insights into possible mechanisms underlying documented increases in cardiovascular morbidity and mortality in humans exposed to SHS.

Environmental tobacco smoke: respiratory and other health effects

Involuntary exposure to environmental tobacco smoke (ETS) is a serious and entirely preventable public health hazard. It has become clear that ETS adversely affects the health of all who breathe its toxins. Independent of active smoking, ETS exposure is a modifiable risk factor for chronic obstructive pulmonary disease. The expanding body of research presented in this article provides evidence that the damaging consequences of ETS reach far beyond the lungs. Having been determined the third leading cause of preventable death in this country, this is a problem that must be addressed aggressively.

Tobacco industry efforts undermining evidence linking secondhand smoke with cardiovascular disease

BACKGROUND

The scientific consensus that secondhand smoke (SHS) increases cardiovascular disease (CVD) risk by 30% is based on epidemiological and biological evidence. The tobacco industry has contested this evidence that SHS causes CVD, but how and why they have done it has not been described.

METHODS AND RESULTS

About 50 million pages of tobacco industry documents were searched using general keywords and names of industry consultants and scientists. Tobacco industry-funded epidemiological analyses of large data sets were used to argue against an epidemiological association between SHS and CVD and smoke-free regulations, but these analyses all suffered from exposure misclassification problems that biased the results toward the null. More recent industry-funded publications report an increased risk of CVD associated with SHS but claim a low magnitude of risk. When early tobacco industry-funded work demonstrated that SHS increased atherosclerosis, the industry criticized the findings and withdrew funding. RJ Reynolds focused on attacking the biological plausibility of the association between SHS and CVD by conducting indirect platelet aggregation studies, exposure chamber experiments, and literature reviews. Although these studies also suffered from exposure misclassification problems, several produced results that were consistent with a direct effect of SHS on blood and vascular function. Instead, RJ Reynolds attributed these results to an unproven epinephrine-related stress response from odor or large smoke exposure, which supported their regulatory and "reduced-harm" product development efforts. Philip Morris' recent "reduced-harm" efforts seem supportive of a similar corporate agenda.

CONCLUSIONS

The tobacco industry attempted to undermine the evidence that SHS causes CVD to fight smoke-free regulations while developing approaches to support new products that claim to reduce harm. The industry interest in preserving corporate viability has affected the design and interpretation of their cardiovascular studies, indicating the need for great caution in current debates about future tobacco industry regulation and development of reduced-harm tobacco products.

Defending legitimate epidemiologic research: combating Lysenko pseudoscience

This analysis presents a detailed defense of my epidemiologic research in the May 17, 2003 British Medical Journal that found no significant relationship between environmental tobacco smoke (ETS) and tobacco-related mortality. In order to defend the honesty and scientific integrity of my research, I have identified and addressed in a detailed manner several unethical and erroneous attacks on this research. Specifically, I have demonstrated that this research is not "fatally flawed," that I have not made "inappropriate use" of the underlying database, and that my findings agree with other United States results on this relationship. My research suggests, contrary to popular claims, that there is not a causal relationship between ETS and mortality in the U.S. responsible for 50,000 excess annual deaths, but rather there is a weak and inconsistent relationship. The popular claims tend to damage the credibility of epidemiology. In addition, I address the omission of my research from the 2006 Surgeon General's Report on Involuntary Smoking and the inclusion of it in a massive U.S. Department of Justice racketeering lawsuit. I refute erroneous statements made by powerful U.S. epidemiologists and activists about me and my research and I defend the funding used to conduct this research. Finally, I compare many aspect of ETS epidemiology in the U.S. with pseudoscience in the Soviet Union during the period of Trofim Denisovich Lysenko. Overall, this paper is intended to defend legitimate research against illegitimate criticism by those who have attempted to suppress and discredit it because it does not support their ideological and political agendas. Hopefully, this defense will help other scientists defend their legitimate research and combat "Lysenko pseudoscience."

Chimney stove intervention to reduce long-term wood smoke exposure lowers blood pressure among Guatemalan women

BACKGROUND AND OBJECTIVE

RESPIRE, a randomized trial of an improved cookstove, was conducted in Guatemala to assess health effects of long-term reductions in wood smoke exposure. Given the evidence that ambient particles increase blood pressure, we hypothesized that the intervention would lower blood pressure.

METHODS

TWO STUDY DESIGNS WERE USED: a) between-group comparisons based on randomized stove assignment, and b) before-and-after comparisons within subjects before and after they received improved stoves. From 2003 to 2005, we measured personal fine particle (particulate matter with aerodynamic diameter < 2.5 microm; PM(2.5)) exposures and systolic (SBP) and diastolic blood pressure (DBP) among women > 38 years of age from the chimney woodstove intervention group (49 subjects) and traditional open wood fire control group (71 subjects). Measures were repeated up to three occasions.

RESULTS

Daily average PM(2.5) exposures were 264 and 102 microg/m(3) in the control and intervention groups, respectively. After adjusting for age, body mass index, an asset index, smoking, secondhand tobacco smoke, apparent temperature, season, day of week, time of day, and a random subject intercept, the improved stove intervention was associated with 3.7 mm Hg lower SBP [95% confidence interval (CI), -8.1 to 0.6] and 3.0 mm Hg lower DBP (95% CI, -5.7 to -0.4) compared with controls. In the second study design, among 55 control subjects measured both before and after receiving chimney stoves, similar associations were observed.

CONCLUSION

The between-group comparisons provide evidence, particularly for DBP, that the chimney stove reduces blood pressure, and the before-and-after comparisons are consistent with this evidence.

Effects of passive smoking on heart rate variability, heart rate and blood pressure: an observational study

BACKGROUND

Exposure to environmental tobacco smoke (ETS) has been shown to increase the risk for cardiovascular diseases and death, and autonomic dysfunction (specifically, reduced heart rate variability (HRV)) is a predictor of increased cardiac risk. This study tests the hypothesis that ETS exposure reduces HRV in the general population and discusses possible pathways.

METHODS

This cross-sectional study was conducted between 2001 and 2003 and is part of the SAPALDIA (Swiss Cohort Study on Air Pollution and Lung Diseases in Adults) study. The analysis included 1218 randomly selected non-smokers aged 50 and above who participated in 24-h electrocardiogram recordings. Other examinations included an interview, investigating health status (especially respiratory and cardiovascular health and health relevant behaviours and exposure to ETS) and measurements of blood pressure, body height and weight.

RESULTS

Subjects exposed to ETS at home or at work for more than 2 h/day had a difference of -15% in total power (95%CI: -26 to -3%), low frequency power (-28 to -1%), low/high frequency ratio (-26 to -3%) and -18% (-29 to -4%) in ultralow frequency power of HRV compared with subjects not exposed to ETS at home or work. We also found a 2.7% (-0.01 to 5.34%) higher heart rate during the recording in exposed subjects.

CONCLUSIONS

Exposure to ETS at home and work is associated with lower HRV and with higher heart rate in an ageing population. Our findings suggest that exposure to ETS increases cardiac risk through disturbances in the autonomic nervous system.

Environmental tobacco smoke and coronary heart disease mortality in the United States--a meta-analysis and critique

Several major meta-analyses have concluded that exposure to environmental tobacco smoke (ETS) increases the risk of coronary heart disease (CHD) by about 25% among never smokers. However, these reviews have excluded a large portion of the epidemiologic evidence on questionable grounds and have been inconsistent in the selection of the results that are included. We conducted an updated meta-analysis and critique of the evidence on ETS exposure and its relationship to death from CHD among never smokers. Our focus is on the U.S. cohort studies, which provide the vast majority of the available evidence. ETS exposure is assessed in terms of spousal smoking, self-reported estimates, and personal monitoring. The epidemiologic results are summarized by means of overall relative risks and dose-response relationships. The methodological issues of publication bias, exposure misclassification, and confounding are discussed. Several large studies indicate that spousal smoking history is a valid measure of relative exposure to ETS, particularly for females. Personal monitoring of nonsmokers indicates that their average ETS exposure from a smoking spouse is equivalent in terms of nicotine exposure to smoking less than 0.1 cigarettes per day. When all relevant studies are included in the meta-analysis and results are appropriately combined, current or ever exposure to ETS, as approximated by spousal smoking, is associated with roughly a 5% increased risk of death from CHD in never smokers. Furthermore, there is no dose-response relationship and no elevated risk associated with the highest level of ETS exposure in males or females. An objective assessment of the available epidemiologic evidence indicates that the association of ETS with CHD death in U.S. never smokers is very weak. Previous assessments appear to have overestimated the strength of the association.

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.

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.

Cigarette smoking among spouses: another risk factor for stroke in women

BACKGROUND AND PURPOSE

It is well known that passive exposure to cigarette smoking increases the risk of coronary events, but the effect on the risk of stroke is not well defined. We performed this study to determine the effect of cigarette smoking among spouses on the risk of developing stroke and ischemic stroke among a nationally representative sample of women.

METHODS

We examined the association between history of smoking among spouses with the incidence of stroke in a national cohort of 5379 women who participated in the First National Health and Nutrition Examination Survey Epidemiologic Follow-Up Study.

RESULTS

During a mean follow-up of 8.5 years, the risk was significantly increased for all strokes (relative risk, 5.7; 95% CI, 1.4 to 24) and ischemic stroke (relative risk, 4.8; 95% CI, 1.2 to 20) among cigarette-smoking women with a cigarette-smoking spouse compared with those with a nonsmoking spouse after adjusting for other cardiovascular risk factors.

CONCLUSIONS

The study provides new evidence linking spousal smoking to stroke.

Environmental tobacco smoke exposure in public places of European cities

BACKGROUND

Exposure to environmental tobacco smoke (ETS) has important public health implications. The results of the first European multi-centre study that measured ETS exposure in a range of public places (transport, educational settings, and leisure facilities such as bars and restaurants) are presented.

METHOD

Nicotine vapour phase was measured using ETS passive samplers containing a filter treated with sodium bisulfate.

RESULTS

Bars and discos are the places with the highest concentrations of nicotine from ETS, median ranging from 19 to 122 microg/m(3). Restaurants had the next highest values. Concentrations of nicotine generally range from 0.1-5 microg/m(3) in airports, and from 0.5-10 microg/m(3) in train stations. Nicotine was also found in schools and universities, yet schools tended to have the lowest concentrations compared to all the other public places sampled. In hospitals levels were generally below 5 microg/m(3).

CONCLUSIONS

Although there is some variability between cities, this study shows that tobacco smoke is present in most of the studied public places. The study also showed that in areas where smoking is prohibited, concentrations of nicotine are lower than in areas where smoking is allowed but they are not zero. The results of this study indicate that policies should be implemented that would effectively reduce levels of tobacco smoke in public areas.

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.

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 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.

Indoor air pollution: a global health concern

Indoor air pollution is ubiquitous, and takes many forms, ranging from smoke emitted from solid fuel combustion, especially in households in developing countries, to complex mixtures of volatile and semi-volatile organic compounds present in modern buildings. This paper reviews sources of, and health risks associated with, various indoor chemical pollutants, from a historical and global perspective. Health effects are presented for individual compounds or pollutant mixtures based on real-world exposure situations. Health risks from indoor air pollution are likely to be greatest in cities in developing countries, especially where risks associated with solid fuel combustion coincide with risk associated with modern buildings. Everyday exposure to multiple chemicals, most of which are present indoors, may contribute to increasing prevalence of asthma, autism, childhood cancer, medically unexplained symptoms, and perhaps other illnesses. Given that tobacco consumption and synthetic chemical usage will not be declining at least in the near future, concerns about indoor air pollution may be expected to remain.

Mortality from occupational exposure to environmental tobacco smoke in Finland

This article aimed to estimate the mortality from exposure to passive smoking at work in Finland. The estimation used statistics on causes of death, exposure prevalences, and risk ratios from epidemiologic studies. The attributable fractions of cause-specific mortality from passive smoking at work were 2.8% for lung cancer, 1.1% for chronic obstructive pulmonary disease, 4.5% for asthma, 3.4% for ischemic heart disease, and 9.4% for cerebrovascular stroke. Altogether, about 250 fatalities were estimated to have occurred in 1996. This is approximately 0.9% of the total mortality in the Finnish population in the relevant disease and age categories. The magnitude of mortality related to past occupational exposure to passive smoking is considerable. Preventive measures to reduce environmental tobacco smoke in the workplace will be a powerful means of reducing the high burden of respiratory and cardiovascular diseases.

Acute exposure to environmental tobacco smoke and heart rate variability

Environmental tobacco smoke (ETS) has been associated with cardiovascular mortality. Pathophysiologic pathways leading from ETS exposure to cardiopulmonary disease are still being explored. Reduced cardiac autonomic function, as measured by heart rate variability (HRV), has been associated with cardiac vulnerability and may represent an important pathophysiologic mechanism linking ETS and risk of cardiac mortality. In this study we evaluated acute ETS exposure in a commercial airport with changes in HRV in 16 adult nonsmokers. We conducted ambulatory electrocardiographic (ECG) monitoring for 8-hr periods while participants alternated 2 hr in nonsmoking and smoking areas. Nicotine and respirable suspended particle concentrations and participants' blood oxygen saturation were also monitored. We calculated time and frequency domain measures of HRV for periods in and out of the smoking area, and we evaluated associations with ETS using comparative statistics and regression modeling. ETS exposure was negatively associated with all measures of HRV. During exposure periods, we observed an average decrement of approximately 12% in the standard deviation of all normal-to-normal heart beat intervals (an estimate of overall HRV). ETS exposures were not associated with mean heart rate or blood oxygen saturation. Altered cardiac autonomic function, assessed by decrements in HRV, is associated with acute exposure to ETS and may be part of the pathophysiologic mechanisms linking ETS exposure and increased cardiac vulnerability.

Summary: workshop on health risks attributable to ETS exposure in the workplace

This 1998 workshop was convened to address the health risks of exposure to environmental tobacco smoke (ETS) in the workplace. It was paired with a 1997 workshop on issues related to ETS exposure in work environments ((italic)1(/italic)). In the 1998 workshop, a multidisciplinary group of participants was charged with reviewing evidence on the quantitative risks to health posed by ETS and to discuss development of risk assessment methodology for the future. The overall charges for the present workshop were to consider various health outcomes and make recommendations regarding those health outcomes to be included in assessment of health risk resulting from ETS in the workplace; to consider available studies addressing these health outcomes and to evaluate the validity of data for estimating risk from occupational ETS exposure; to review and evaluate mathematical models useful for estimating the risk due to ETS exposure; to examine dose-response models and to characterize the models regarding validity and uncertainty in estimating health risk attributable to ETS exposure in the workplace.