Young adults, ages 20 to 44, with normal lung function who later develop chronic cough and phlegm have a fourfold higher risk of developing chronic obstructive pulmonary disease (COPD).

The results of this 10-year respiratory study appear in the January 2007 issue of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.

Isa Cerveri, MD, of the division of Respiratory Diseases at San Matteo Hospital and University of Pavia in Italy, and 19 associates showed that the presence of chronic cough and phlegm among study participants was an independent and statistically significant predictor of COPD. Of the 5,002 individuals in the study cohort, 123 were diagnosed with COPD. All participants had normal lung function at baseline.

COPD is the fourth leading cause of death in the United States, killing 122,283 Americans in 2003. It results from chronic bronchitis and emphysema, two lung diseases which frequently co-exist and cause obstruction to airflow that interferes with normal breathing. Smoking is the primary cause of COPD.

“In a large international cohort of individuals from ages 20 to 44, the 10-year cumulative incidence of COPD was 2.8 percent,” said Cerveri. “It was 4.6 percent in adults aged 40 to 44. This finding points out that COPD is a major health problem even in young adults who are usually not considered to be at risk. In agreement with previous research, we found that the progression toward airflow obstruction is a continuous and gradual process, where sudden changes are extremely unlikely.”

Among the study group, about 77 percent of the 123 COPD cases were smokers. In the sample as a whole, about 55 percent smoked.

“Our results show that the presence of chronic cough and phlegm is not an innocent symptom, but is an early marker of airflow obstruction,” said Cerveri.