Association of poor clinical status and heavy exposure to tobacco smoke in patients with cystic fibrosis who are homozygous for the F508 deletion.

We examined the association between clinical status and exposure to tobacco smoke in 44 patients homozygous for the F508 cystic fibrosis mutation. Heavy exposure to tobacco smoke was significantly associated with lower Shwachman scores, poorer results of pulmonary function tests, and a fivefold increase in the number of pulmonary-related hospitalizations during the previous year.