THURSDAY, Aug. 30, 2007 (HealthDay News) -- There are more people around the world suffering from chronic obstructive pulmonary disease (COPD) than previously thought, an international team of researchers reports.
Worse yet, those numbers are bound to increase as the world's population continues to age, claims the study in the Sept. 1 issue of The Lancet.
"COPD is much more common than previous estimates would suggest," said study author Dr. A. Sonia Buist, chief of the division of pulmonary and critical care medicine at Oregon Health & Science University. "We did the study, because there is a huge disconnect between the public and the public health perception of the burden of COPD, and the reality."
COPD is under-diagnosed and under-treated, Buist said.
"COPD is a cumulative response of the lungs to the burden of all that's breathed in over a lifetime," she said. "As populations age, the prevalence of COPD and the burden of COPD is going to increase significantly."
In the study, Buist's group collected data on 9,425 people aged 40 and over who hailed from 12 different countries.
They found that the overall prevalence of severe COPD was 10.1 percent. Among men, it was 11.8 percent and for women, 8.5 percent. These figures contrast with another recent study that placed the overall burden of COPD at 4.3 percent, Buist noted.
In the United States, the overall prevalence of serious COPD is 10.1 percent, the researchers reported.
The number of people with COPD varied throughout world. Cape Town, South Africa, had the highest prevalence of COPD, with 22.2 percent of men and 16.7 percent of women affected, while Hanover, Germany, had the lowest prevalence, with 8.6 percent of men and 3.7 percent of women with serious COPD.
The difference in COPD between men and women is mostly due to differences in smoking habits, the researchers pointed out.
The increasing prevalence of COPD is partly due to the aging population, where the risk of the disease nearly doubles for every 10 years over the age of 40, and also to smoking.
COPD is a lung disease that progressively damages the lungs, making it hard to breathe. The disease obstructs the small airways in the lungs so it is difficult to get air in and out.
The most common cause of COPD is cigarette smoking. In addition, breathing lung irritants, such as pollution, dust or chemicals, over a long period of time also causes or contributes to the condition.
Since there is no cure for COPD, prevention is the best advice Buist has to offer. This means not smoking, avoiding jobs that expose you to pollution and smoke, or wearing protective gear. "It's really cleaning up the air you breathe," she said.
One expert thinks the study highlights a growing public health problem.
"We are beginning to understand that COPD is a major disease burden throughout the world," said Dr. Norman Edelman, chief medical officer at the American Lung Association. "The study also confirms that it's not just smoking, but there are other environmental issues involved."
Edelman noted that smoking and air pollution are important causes of COPD. However, there are other conditions that can contribute, such as uncontrolled asthma. "It's not just smoking and air pollution but other factors, too," he said.
Another report in the same journal says that poor airway function shortly after birth is a risk factor for obstructed breathing among young adults. Therefore, preventing COPD may need to start before birth. One of the culprits could be maternal smoking, the researchers suggested.
Lead researcher Dr. Fernando Martinez, director of the Arizona Respiratory Center at the University of Arizona Health Sciences Center in Tucson, and his colleagues found that people born with poorer lung function continue having breathing problems up to age 22.
This is "a process that could be impaired in utero by both genetic and environmental factors. Among these factors, maternal smoking during pregnancy has been consistently associated with poor lung function in both infants and older children," Martinez's team concluded.
For more on COPD, visit the U.S. National Heart, Lung, and Blood Institute.