The association between environmental tobacco smoke and primary tooth caries

OBJECTIVE: Environmental tobacco smoke (ETS) has been associated with a number of negative health outcomes for exposed children. The goal of this study was to assess the association between ETS and dental caries in a pediatric population. METHODS: This study included 637 Iowa Fluoride Study children whose parents provided socioeconomic information, completed at least three questionnaires during the first year of life, and had a primary dentition exam at age 4-7 years. Households reporting in all questionnaires that someone smoked in the home were categorized as regularly smoking homes. Socioeconomic status (SES) was divided into three groups (low, middle, and high) based on family income and mother's education. Children were classified as having caries if any of the primary teeth had fillings or cavitated lesions at the primary dentition exam. RESULTS: Overall, children residing in regularly smoking homes had a higher prevalence of caries. For the middle SES group and overall, the children from smoking homes had a significantly higher prevalence of caries compared to nonregular/nonsmoking homes (52% vs 24%, P=.05 and 44% vs 25%, P=.002, respectively). After adjusting for age, SES, toothbrushing frequency, total ingested fluoride, and combined intake of soda pop and powdered drink beverages, the relationship of smoking and caries still remained significant (odds ratio [OR]=3.38; P=.001). CONCLUSIONS: Environmental tobacco smoke was associated with an increased risk of caries among children.     

Prostitution and other cofactors in preinvasive and invasive lesions of the cervix

OBJECTIVE: To examine risk factors for preinvasive and invasive lesions of the cervix in Venezuelan female sex workers (FSW). METHODS: A total of 438 FSW were analysed. Each FSW had their clinical history recorded, a gynaecological examination, a Pap smear and a colposcopic examination of the cervix. A cervical biopsy was taken under colposcopic guidance when there was an abnormal epithelium. The statistical methods used were Student's t-test, chi(2) test and logistic regression. RESULTS: The sex workers' mean age was 32.1 +/- 7.9 years old (mean +/- standard deviation). The age of the first sexual intercourse activity for the FSW was 15.9 +/- 2.1 years. Sixty-four of the 84 women (76.2%) who had cervical biopsies had preinvasive and invasive lesions; 41 (9.4%) had cervical intra-epithelial neoplasia (CIN) 1, 12 (2.7%) had CIN 2, eight (1.8%) had CIN 3, two (0.5%) had microinvasive carcinoma, and one (0.2%) had invasive carcinoma. Forty of these 64 women (62.5%) with preinvasive or invasive lesions had a concurrent histological diagnosis of human papilloma virus (HPV) infection (P < 0.0001). The FSW with cervical pathology were younger (P < 0.05) and had their first sexual intercourse earlier (P < 0.02) than FSW with no pathology. Two hundred and seventy-six (63%) of the FSW were current smokers, and 47 of these women (17.6%) had cervical pathology (P < 0.03). CONCLUSIONS: First sexual experience before 20 years of age, cigarette smoking and HPV infection were high-risk factors for preinvasive and invasive lesions of the cervix in Venezuelan FSW.     

The value of risk‐free cigarettes – do smokers underestimate the risk?

The health risk of smoking is valued using the contingent valuation method, applied to a Swedish sample of smokers. The respondents were asked to put a value on newly developed cigarettes with no associated health risks. The average additional willingness to pay for the new cigarettes is estimated to be between 10 and 41 SEK per pack, where the variation is due to statistical method, discounting, and whether the open-ended or closed-ended question format is used. Using medical data on life shortening effects of smoking, the results indicate rather low values put on a lost life-year, compared to most existing estimates based on other methods. This may indicate that smokers do underestimate the health risk of smoking. There is also initial optimism-bias regarding people's own ability to quit smoking at will. However, there are remaining methodological questions and we found little or no sensitivity to scope.     

Environmental tobacco smoke and breast cancer incidence

To evaluate whether environmental tobacco smoke (ETS) influences breast cancer incidence, data from a population-based case-control study were analyzed. Respondents with available ETS information assessed by in-person questionnaires included 1356 newly diagnosed cases and 1383 controls. Relative to nonsmokers who reported no residential ETS exposure throughout the life course, the odds ratios (OR) for breast cancer were not substantially elevated in relation to ETS exposure, active smoking, or a joint measure of active and passive smoking (OR, 1.15, 95% CI, 0.90, 1.48). An increased OR, however, was noted among nonsmokers who lived with a smoking spouse for over 27 years (2.10, 95% CI, 1.47, 3.02), although no dose-response was evident. Also, among women with hormone-receptor-positive tumors only, the OR for both active and passive smoking was increased (1.42 for ER+ PR+, 95% CI, 1.00, 2.00). Our data suggest that if there is an effect for ETS on breast cancer, that effect is restricted to selected subgroups of women, such as those with long-term exposure from a smoking spouse.     

Apnea and bradycardia due to anaphylaxis to tobacco glycoprotein in the infant rabbit

Prenatal and postnatal exposure to cigarette smoke is associated with an increased incidence of the sudden infant death syndrome, although the cause(s) for this is unknown. Tobacco glycoprotein (TGP), a group of proteins purified from cured tobacco leaves and present in cigarette smoke, have been shown to cause anaphylaxis in excised hearts and lungs of adult rabbits that were neonatally sensitized to TGP and later rechallenged. We sought to determine whether anaphylaxis occurred in live infant rabbits who were neonatally sensitized to TGP. At the age of 1 day, 12 animals were sensitized to TGP (0.1mg in 0.25 cc alum) via intraperitoneal injection (i.p.i.) followed by a booster ipi at the age of 30 days (TGP-S). Seven animals received i.p.i. of antigen-free alum only (controls). All animals underwent an intravenous TGP challenge at age 42+/-2 days. Heart rate (HR) and respiratory rate (RR) were recorded for 2 min prior to and 5 min after the challenge. Baseline HR (approximately 260) and RR (approximately 120) were similar in all animals. Seven TGP-S animals developed apnea (1.9-4.7s) within 60s of the challenge while none of the controls did. The TGP-S also became bradycardic (the lowest HR over 50 consecutive beats), with the HR decreasing from 260 to 220 vs the controls, whose HR remained constant (approximately 250). We conclude that some rabbits neonatally sensitized to TGP develop apnea and bradycardia upon further intravenous TGP challenge. These studies suggest that cigarette smoke exposure may be associated with a higher rate of SIDS via an anaphylactic mechanism.     

Strategies to Increase Smoke Alarm Use in High-Risk Households

A 3-year project was undertaken to evaluate two methods of promoting residential smoke alarm installation and maintenance in high risk households across the U.S. Five states (Arkansas, Maine, Maryland, Massachusetts, and North Carolina) participated. The two strategies under study were direct installation of smoke alarms and distribution of a voucher for free smoke alarms. The target population included occupants of high-risk households without working smoke alarms who were approached as part of a door-to-door canvassing program. Fire Safety education was provided to both groups. A follow up assessment conducted 6-12 months post intervention assessed the presence and functional status of smoke alarms in each of the two groups. Demographic and fire safety data were also collected at baseline and follow up for each group. 4,455 households were enrolled in the study [Installation Group: 2,206 (49.5%), Voucher Group: 2,249 (50.5%)]. Baseline characteristics of the groups within each state were comparable. Follow up data was obtained on 1,583 installation group households and 1,545 voucher group households. At follow up, 1,421 (89.8%) households in the installation group had working smoke alarms, compared with 997 (65%) households in the voucher group, Odds Ratio 4.82 (95% CI=3.97, 5.85) (p <.0001). On average, 47% of all households enrolled in the voucher group did not redeem their vouchers (range 26-63%). Direct installation of alarms by program staff resulted in working smoke alarms in 90% of households receiving the direct installation intervention. Only 65% of voucher households had functioning alarms at follow up, largely due to failure to redeem vouchers.     

A mechanistic study of cigarette smoke and cyclooxygenase-2 on proliferation of gastric cancer cells

Cigarette smoke has been shown to cause gastric cancer. Overexpression of cyclooxygenase-2 (COX-2) is a common characteristic in gastric malignancy. The present study aimed to explore the correlation between cigarette smoke and COX-2 in the promotion of tumorigenesis in human gastric cancer cells (AGS). We further studied the action of COX-2 on other proto-oncogenes on gastric tumor growth. Results showed that chloroform extract (CE) and ethanol extract (EE) from cigarette smoke dose-dependently stimulated gastric cancer cell proliferation, which was accompanied with an activation of ornithine decarboxylase (ODC) activity, COX-2, and c-myc expressions. Both antisense of c-myc and alpha-difluoromethylornithine (DFMO, specific ODC inhibitor) inhibited cell proliferation without affecting COX-2 expression in response to cigarette smoke extracts (CSE). However, selective COX-2 inhibitor (SC-236) not only blocked the proliferative activity but also the ODC activity and c-myc protein expression by CSE in gastric cancer cells. Further, supplementation of exogenous prostaglandin (PG) E(2) reversed all the inhibitory actions of SC-236. Our results underline the importance of COX-2 in the cancer-promoting effect of CSE and its modulation on its downstream growth-related genes, such as c-myc and ODC in cancer cell proliferation. These results reveal that CSE-induced gastric carcinogenesis is via the COX-2/c-myc/ODC and PGE(2)-dependent pathway. Hence, selective COX-2 inhibitor could be an effective therapeutic agent for gastric cancer in smokers.     

Secondhand smoke exposure in adulthood and risk of lung cancer among never smokers: a pooled analysis of two large studies

The interpretation of the evidence linking exposure to secondhand smoke with lung cancer is constrained by the imprecision of risk estimates. The objective of the study was to obtain precise and valid estimates of the risk of lung cancer in never smokers following exposure to secondhand smoke, including adjustment for potential confounders and exposure misclassification. Pooled analysis of data from 2 previously reported large case-control studies was used. Subjects included 1263 never smoking lung cancer patients and 2740 population and hospital controls recruited during 1985-1994 from 5 metropolitan areas in the United States, 11 areas in Germany, Italy, Sweden, United Kingdom, France, Spain and Portugal. Odds ratios (ORs) of lung cancer were calculated for ever exposure and duration of exposure to secondhand smoke from spouse, workplace and social sources. The OR for ever exposure to spousal smoking was 1.18 (95% CI = 1.01-1.37) and for long-term exposure was 1.23 (95% CI = 1.01-1.51). After exclusion of proxy interviews, the OR for ever exposure from the workplace was 1.16 (95% CI = 0.99-1.36) and for long-term exposure was 1.27 (95% CI = 1.03-1.57). Similar results were obtained for exposure from social settings and for exposure from combined sources. A dose-response relationship was present with increasing duration of exposure to secondhand smoke for all 3 sources, with an OR of 1.32 (95% CI = 1.10-1.79) for the long-term exposure from all sources. There was no evidence of confounding by employment in high-risk occupations, education or low vegetable intake. Sensitivity analysis for the effects of misclassification (both positive and negative) indicated that the observed risks are likely to underestimate the true risk. Clear dose-response relationships consistent with a causal association were observed between exposure to secondhand smoke from spousal, workplace and social sources and the development of lung cancer among never smokers.     

Tobacco use by university students,Lebanon, 2001

Aims The objective was to determine the prevalence of smoking [cigarettes and/or narghile (i.e. water‐pipe)] among university students and to examine multiple correlates. Design Cross‐sectional. Setting Beirut, Lebanon. Participants A proportionate random sample of 1964 students from public and private universities in Beirut, Lebanon. Measurements Participants completed a self‐administered anonymous questionnaire that included demographic and scholastic items and health behavioral aspects, including smoking, alcohol, physical activity, weight control measures and seat belt use. Findings The overall prevalence of smoking was 40% (21.1%, 7.6% and 11.3% of the students were smoking only narghile, only cigarettes and both cigarettes and narghile, respectively). Regression analyses showed that males, those of non‐Lebanese origin, pursuing undergraduate degrees, performing risky weight control measures and drinking excessive amounts of alcohol had increased odds of smoking cigarettes. Also, age, high level of paternal education and field of study were significant predictors. Narghile smoking was significantly higher among males who drank excessive alcohol. Conclusions The authors advocate a collaborative effort to alleviate the consequences of smoking among university students.     

Cigarette smoking and perceived health in school dropouts: a comparison of Mexican American and non-Hispanic white adolescents

OBJECTIVE: To examine the relations between educational attainment and health (cigarette smoking and perceived health) in Hispanic adolescents. METHOD: Participants included 3,360 Mexican American and non-Hispanic white adolescents ranging in age from 12 to 21 years. The sample included school dropouts, academically at-risk students, and control students. RESULTS: School dropouts were 6.46 times more likely and academically at-risk students were 2.80 times more likely to smoke heavily than were control students. In addition, school dropouts reported poorer health than did their peers. Results suggest that the relation between educational attainment and perceived health is mediated by cigarette smoking. CONCLUSIONS: Increased awareness of educational attainment as a significant risk factor for smoking in Hispanic adolescents will enable smoking cessation services to be targeted more effectively.