Ventilatory lung function in young cigarette smokers: a study of susceptibility

The objective of this study was to estimate the effect of cigarette smoking on ventilatory lung function among young adults with special emphasis on the recognition of susceptible subgroups. In a cross-sectional study of 1,044 adults aged 15-40 yrs, a statistically significant linear relationship between quantity of smoking in cigarette-years and level of forced expiratory volume in one second (FEV1) was found. Among current cigarette smokers, FEV1 level was on average 35 ml lower for each 100 cigarette-years of exposure (corresponding to smoking of ten cigarettes per day for 10 yrs) compared to lifelong nonsmokers in a linear regression adjusted for confounding. Potentially susceptible subgroups were studied by introducing interaction terms between quantitative smoking and gender, wheezing, atopy, asthma, childhood respiratory illness and exposure to environmental tobacco smoke during the growth period, to the additive linear regression model explaining the FEV1 level. Wheezing was found to modify the effect of smoking significantly: the FEV1 level was on average 68 ml lower for each 100 cigarette-years due to interaction between smoking and wheezing. An introduction of the interaction term eliminated the independent effect of smoking. The results suggest that the detrimental effect of smoking on FEV1 in young adults may be limited to individuals with wheezing. Thus, the presence of wheezing among smokers indicates a higher risk for low level of ventilatory lung function compared to smokers who do not wheeze.

This article has been cited by other articles:

				G. G. Apostol, D. R. Jacobs Jr., A. W. Tsai, R. S. Crow, O. D. Williams, M. C. Townsend, and W. S. Beckett Early Life Factors Contribute to the Decrease in Lung Function between Ages 18 and 40: The Coronary Artery Risk Development in Young Adults Study Am. J. Respir. Crit. Care Med., July 15, 2002; 166(2): 166 - 172. [Abstract] [Full Text] [PDF]

				S. Humerfelt, G. E Eide, and A. Gulsvik Association of years of occupational quartz exposure with spirometric airflow limitation in Norwegian men aged 30-46 years Thorax, August 1, 1998; 53(8): 649 - 655. [Abstract] [Full Text]

				B Hemmelgarn and P Ernst Airway function among Inuit primary school children in far northern Quebec Am. J. Respir. Crit. Care Med., December 1, 1997; 156(6): 1870 - 1875. [Abstract] [Full Text]