Lung Function at Birth May Predict Asthma Risk
Study finding might one day lead to improved screening methods
WEDNESDAY, Oct. 18, 2006 (HealthDay News) -- The way a healthy infant's lungs function at birth may provide clues to that child's future respiratory health, concludes a new study from Norway.
The study found that babies who performed poorly on lung function tests at birth were more likely to develop asthma before the age of 10.
"The study tells us that some children who later have asthma, breathe abnormally already at birth," said one of the study's authors, Dr. Geir Haland, a research fellow and assistant consultant at Ulleval University Hospital in Oslo. "Thus we may infer from this that the disease process of asthma may express itself through lung function [tests a] long time before symptoms appear and that, in some children, it may appear that the disease process is established already before birth."
The study findings are published in the Oct. 19 issue of the New England Journal of Medicine.
About 20 million Americans -- nine million of them children -- have been diagnosed with asthma, according to the American Academy of Allergy, Asthma and Immunology (AAAAI). Between 1980 and 1994, the rate of childhood asthma increased by 160 percent. Children miss nearly 13 million school days annually due to the disease.
There's no way to know ahead of time which children will develop asthma, although a family history indicates a higher risk.
To assess whether or not lung function at the time of birth indicates a higher risk of developing asthma during childhood, the Norwegian researchers recruited 616 children who were 10 years old. All of these children had been given lung-function tests shortly after they were born. All were born full-term and appeared healthy.
At 10, their parents agreed to a thorough asthma evaluation that included lung function tests, a test designed to measure airway response to an irritant, blood samples and allergy testing.
Twenty percent of the children -- or their parents -- reported a history of asthma and 11 percent currently had asthma.
About 16 percent of those children who had normal lung function at birth had a history of asthma, compared to just over 24 percent of those with less than optimal lung function as infants. Of those who currently had asthma, 7.5 percent had normal lung function tests as newborns, compared to 14.6 percent of those who had poorer lung function at birth.
"This is an exciting early step in understanding the development and pathogenesis of asthma," said asthma specialist Dr. Sai Nimmagadda, an attending physician at Children's Memorial Hospital and an assistant professor of pediatrics at the Feinberg School of Medicine at Northwestern University in Chicago.
"Is the risk profile present at birth? Could we predict asthma at birth? If a baby has a high-risk [due to family history], is this another screening tool that could be used?" said Nimmagadda. "Right now, it would still be years from developing such a protocol. The test is probably very expensive and isn't standardized or easy to do."
Haland said: "We can not from our study recommend that lung function be routinely tested at birth as the equipment is relatively expensive and bulky. In addition, we do not know today what preventive [steps] should be applied in order to prevent children at risk from developing asthma."
To learn more about asthma, visit the National Heart, Lung, and Blood Institute.