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

Abstract

Objective: To investigate the association between environmental tobacco smoke (ETS) exposure (at least 30 minutes a day) and the risk of developing acute coronary syndromes (ACS). Design and setting: The CARDIO2000 is a case-control study which was conducted in Greece from 2000 to 2001. Cases included 847 individuals with a first event of ACS and 1078 cardiovascular disease-free controls. Cases and controls were frequency matched on age (within three years of age), sex, and region. Main outcome measures: ACS was defined as a diagnosis of first acute myocardial infarction or unstable angina. Main independent variable: Exposure to ETS was measured by self report as follows: after the second day of hospitalisation for the cases, and at the entry for the controls, participants were asked whether they were currently exposed to tobacco smoke from other people (home and/or work) for more than 30 minutes a day. The responses were categorised into three levels: no exposure, occasional exposure (< 3 times per week), and regular exposure. In addition participants were asked how many years they had been exposed. Because these were self reported assessments and prone to bias, the results were compared to reports obtained from subjects' relatives or friends, using the Kendal's τ coefficient that showed high agreement. Results: 731 (86%) of the patients and 605 (56%) of the controls reported current exposure of 30 minutes per day or more to ETS. Among current non-smokers, cases were 47% more likely to report regular exposure to ETS (odds ratio (OR) 1.47, 95% confidence interval (CI) 1.26 to 1.80) compared to controls. Exposure to ETS at work was associated with a greater risk of ACS compared to home exposure (+97% v +33%). The risk of ACS was also raised in active smokers (OR 2.83, 95% CI 2.07 to 3.31) regularly exposed to ETS. Conclusions: This study supports the hypothesis that exposure to ETS increases the risk of developing ACS. The consistency of these findings with the existing totality of evidence presented in the literature supports the role of ETS in the aetiology of ACS.

Cardiovascular Effects of Secondhand Smoke

“…There was no significant heterogeneity (Pϭ0.1), but we used random-effects model to be conservative. Citations for individual studies are as follows: Steenland et al, 152 Kawachi et al, 153 Humble et al, 154 Hole et al, 155 Garland et al, 156 Hirayama, 157 Butler, 158 Sandler et al, 159 Svndsen et al, 160 He et al, 6 Roselund et al, 26 McElduff et al, 161 Ciruzzi et al, 162 LaVecchia et al, 163 Lee et al, 164 Muscat and Wynder, 165 Jackson, 166 Dobson et al, 167 Pitsavos et al, 24 and Whincup et al 28 …”

“…Six meta-analyses have been published, [3][4][5][6][7]22 all yielding relative risks of heart disease from passive smoking that range between 1.2 and 1.3. Since the last meta-analysis was published, we found 6 new epidemiological studies on the association of passive smoking with heart disease (4 case-control [23][24][25][26] and 2 cohort studies 27,28 ). We excluded 2 23,25 of 3 [23][24][25] case-control reports on the same data set and 1 cohort study because of serious misclassification bias.…”

“…Since the last meta-analysis was published, we found 6 new epidemiological studies on the association of passive smoking with heart disease (4 case-control [23][24][25][26] and 2 cohort studies 27,28 ). We excluded 2 23,25 of 3 [23][24][25] case-control reports on the same data set and 1 cohort study because of serious misclassification bias. 27,29 Figure 1 shows the results of the 29 studies as the risk of ischemic heart disease in never-smokers exposed to SHS relative to the risk in those who were not exposed to SHS.…”

Second Hand Smoke Exposure and Survival in Early-Stage Non–Small-Cell Lung Cancer Patients

“…SHS exposure may occur at different locations including home (including childhood exposure and exposure from spouse or other family members), work (occupational exposure), and leisure places (exposure at public places other than work). The exposure intensity or frequency in work places is generally higher than that of at home or leisure places (11), and a previous study has suggested that SHS exposure at work places may have a stronger effect on NSCLC risk than exposure at home or leisure places (12). We hypothesized that SHS exposure is associated with worse survival in NSCLC patients, before and after adjusting for cumulative MSS exposure.…”

Second hand smoke, age of exposure and lung cancer risk

“…Due to public health education and as a result of legislation in several developed countries, exposure to second hand smoke is declining at work and public places but direct marketing to younger populations by tobacco companies has contributed to continued high exposure among youths (49)(50)(51)(52). The intensity or frequency of exposure in work places has been noted to be generally higher than that of at home or leisure places (53), and results from a previous study has suggested that SHS exposure at work places may have a stronger effect on NSCLC risk than exposure at home or at leisure places (54).…”