Exposure to secondhand smoke is associated with adverse effects on lung function among persons with cystic fibrosis, with this effect being worse for persons with certain gene variations, according to a study in the January 30 issue of JAMA: The Journal of the American Medical Association.
Cystic fibrosis (CF) is a fatal disorder that affects more than 30,000 individuals in the United States, with the major cause of illness and death being progressive obstructive lung disease. “Despite public health warnings, including a recent U.S. surgeon general's report stating that there is no risk-free level of secondhand smoke exposure, substantial numbers of individuals with CF are exposed to secondhand smoke. Unfortunately, published studies have been inconsistent in associating poorer clinical outcomes in patients with CF with secondhand smoke exposure,” the authors write.
J. Michael Collaco, M.D., of Johns Hopkins University School of Medicine, Baltimore, and colleagues conducted a study examining several issues including whether secondhand smoke exposure is associated with worse lung disease and other outcomes in individuals with CF, and if the gene-environment interactions between the CF-causing gene (CFTR) or the transforming growth factor â1 (TGFâ1) gene influence the effect of secondhand smoke exposure on lung function. The researchers analyzed data from the U.S. Cystic Fibrosis Twin and Sibling Study, with missing data supplemented by the Cystic Fibrosis Foundation Data Registry. Of the 812 participants with data concerning secondhand smoke exposure in the home, 188 (23.2 percent) were exposed. Of the 780 participants with data showing their mother's smoked during pregnancy, 129 (16.5 percent) were exposed.