July 10, 2006

Emphysema less severe in black smokers: study

By Amanda Beck

WASHINGTON (Reuters) - Emphysema is less severe in black
smokers than in their white counterparts, researchers reported
on Monday.

This suggests that blacks respond differently to cigarette
smoke or that genetic and environmental factors may slightly
alter their lung structure, the researchers said.

"This data may give us some clues to hone in on how
emphysema develops," said Dr. Wissam Chatila, lead author on
the study to be published in the journal Chest.

Researchers have long known that emphysema is the only
smoking-related disease less common among blacks than whites.
This study showed that when blacks develop the disease, it is
also distributed differently in their lungs, the researchers
from the Temple University School of Medicine said.

Emphysema is a chronic lung disease characterized by the
destruction of lung tissue or the loss of its elasticity.

White emphysema patients are more likely than blacks to
have damaged tissue in the upper parts of their lungs,
according to the X-rays of 64 patients enrolled in the National
Emphysema Treatment Trial, the researchers said.

In spite of this, other medical exams showed that the
breathing of the black emphysema patients was just as
debilitated as the whites, possibly due to factors other than
the disease, the researchers said.

"This indicates that there must be something else going
on," senior author Dr. Gerard Criner said.

His team has speculated that genetics and environmental
factors may cause African Americans to develop smaller airways
in their lungs, making them more prone to bronchitis and other
lung obstructions.

This might explain why - even with less severe cases of
emphysema - they continue to score poorly on exams measuring
lung function and exercise ability.