Many non-smokers develop lung obstruction

NEW YORK (Reuters Health) - It hardly seems fair but nearly one in four Americans with airway obstruction have never smoked, a new analysis shows.

The majority of these cases are unexplained, Dr. Ronald J. Halbert of Cerner Health Insights in Beverly Hills, California told Reuters Health. "The bottom line is that we really don't know what's going on in these people very well," he said.

Chronic obstructive pulmonary disease (COPD) is typically considered a disease of cigarette smokers, Halbert and his colleagues note in the American Journal of Medicine, and little is known about the illness in individuals who have never smoked. "There are some doctors who think COPD doesn't exist in never smokers," Halbert commented.

Halbert's group investigated the percentage of adults in the Third National Health and Nutrition Examination Survey (NHANES III) who had airway obstruction.

Forty-two percent of the survey participants between 30 and 80 years old had never smoked, and never-smokers accounted for 23 percent of the cases of lung obstruction.

Among the never-smokers with lung obstruction, 19 percent reported being diagnosed with asthma, while 12.5 percent reported COPD, "leaving 68.5 percent with no prior respiratory diagnosis," the investigators write.

It's possible, Halbert noted, that the mechanism behind lung obstruction in never-smokers may be completely different than that involved in smoking-related COPD. More research is needed to answer this question, he said.

In the meantime, Halbert advised doctors: "Don't completely ignore the possibility of COPD in your patients who have never smoked."

SOURCE: American Journal of Medicine, December 2005.