Lung disease risk may be higher for female smokers
NEW YORK (Reuters Health) - Women who smoke are at greater risk than male smokers of developing lung diseases such as emphysema and chronic bronchitis, new research from China suggests.
Such illnesses, known collectively as chronic obstructive pulmonary disease (COPD), are the second leading cause of death in mainland China, Dr. Fei Xu of Nanjing Medical University in Nanjing and colleagues note.
Cigarette smoking and exposure to indoor air pollution from burning coal and other fuels are known COPD risk factors, the researchers add, but no research in urban or rural China has investigated the amount that smoking contributes to COPD risk.
To measure the relationship and clarify the role of indoor air pollution, the researchers compared 1,743 people with COPD to 1,743 healthy controls matched by age, sex and residence. Just over half of the men in the study were smokers, while 5.3 percent of the women smoked. Participants who smoked were divided into three groups based on how many cigarettes they had smoked in their lifetime.
Smokers who consumed the fewest cigarettes had a 40-percent greater risk of COPD, while the middle group of smokers had a 55-percent increased risk and the heaviest smokers had a 77-percent greater risk, the researchers found.
There was no statistically significant link between the type of fuel people used and COPD, but the researchers did find a weak link between using coal for winter heat and increased COPD risk in the non-smokers, in women in particular.
The researchers also found that women smokers were 20 percent more likely to develop COPD than men were, but the reason for this is not clear.
"Our findings clearly support the fact that the highest priority in terms of public health initiatives to prevent COPD is to stop cigarette smoking, especially in populations such as the one studied, in which cigarette smoking is highly prevalent," they conclude.
SOURCE: Respirology, November 2007.