Both environmental tobacco smoke and personal smoking is related to asthma and wheeze in teenagers.

BACKGROUND: Environmental tobacco smoke (ETS) has been reported as a significant risk factor for childhood asthma. Among adults, personal smoking is a major cause of respiratory symptoms and diseases. The effects of these exposures on the prevalence of asthma and wheeze among teenagers are less well known. OBJECTIVE: The aim was to study the independent and combined effects of ETS and personal smoking on the prevalence of asthma and wheeze in teenagers. METHODS: A longitudinal study of asthma and allergic diseases in schoolchildren has been in progress in Northern Sweden since 1996. All children aged 7-8 years in three municipalities were invited and 3430 (97%) participants have been followed by annual questionnaires. At the age 16-17 years, 82% of the initial participants took part in the 2005 survey. RESULTS: Prevalence of physician-diagnosed asthma, ever wheeze and current wheeze was significantly higher among those exposed to maternal ETS and among daily smokers. In multivariate analyses, maternal ETS was a significant risk factor for physician-diagnosed asthma and ever wheeze (OR 1.3-1.5) and personal daily smoking for current wheeze (OR 2.0). ORs for asthma and ever wheeze were highest among daily smokers who were also exposed to maternal ETS with ORs of 1.7 and 2.5, respectively. A significant dose-response association between number of cigarettes/day and the prevalence of wheeze was also found. CONCLUSIONS: Both ETS and personal smoking were significantly related to asthma and wheeze in teenagers. Maternal ETS exposure was associated with lifetime symptoms, but daily smoking among the teenagers was more strongly related to current symptoms.

Factors related to tobacco use among teenagers.

AIM: To examine tobacco use among teenagers, identify factors related to tobacco use, as well as evaluate the outcome of a smoking prevention program. METHODS: From age 7/8 to 14/15, annual questionnaires about asthma and allergy have been completed in the OLIN paediatric study in Northern Sweden. From 12/13 years, questions about tobacco use, i.e. smoking and snuff, were added. A smoking prevention program was performed during 2 years. RESULTS: Any tobacco use increased from 5.0% at age 12/13 years, to 14.4% at age 14/15. At age 14/15 years, the prevalence of tobacco use was significantly higher among boys than girls (16.7 and 12.0%, respectively). More girls than boys smoked (8.9 and 2.8%, respectively), while use of snuff was more common among the boys (15.6 and 4.2%, respectively). Significant risk factors for smoking were any of the family members currently smoking, OR 6.1 (95% CI 4.0-9.3) and a physician-diagnosed asthma at the age of 14/15 years, OR 1.9 (95% CI 1.2-3.0). A protective factor against tobacco use was participation in sports, OR 0.3 (95% CI 0.2-0.4). The prevention program did not result in less tobacco use, although it may have delayed smoking initiation. CONCLUSION: The patterns of tobacco use differed significantly between boys and girls. Though any tobacco use was more common among boys, girls were more likely to smoke, and boys were more likely to use snuff. Having asthma did not prevent the teenagers from smoking. Since having a smoking family member was the major risk factor for tobacco use, prevention programs should be directed at smoking families in addition to the individuals.