The use of bedding that contains no synthetic materials appears to reduce the risk of developing wheezing in infants, Australian researchers report in the American Journal of Public Health.

“These findings,” lead author Dr. Leigh F. Trevillian told Reuters Health, “emphasize the important role of the infant sleeping environment in the development of asthma. They indicate the need for a greater public health effort to ensure optimal infant sleeping environments that will assist in asthma prevention.”

Trevillian of Australian National University, Canberra and colleagues came to this conclusion after studying data on 883 children who as infants in 1988 were included in a survey and then took part in an asthma study in 1995.

Based on previous work, the researchers developed a theoretical model of house dust mite exposure according to bedding composition. The least house dust mite hospitable bedding was of natural composition. It contained no synthetic material or - as is relatively common in Australia - sheepskin.

The next category was bedding that contained either one type of synthetic material or sheepskin or both. The material associated with the greatest house dust mite exposure was composite bedding containing two or more types of synthetic material with or without sheepskin.

About 64 percent of children were exposed to a single synthetic material, 27 percent had natural fiber bedding, and the remainder were exposed to composite synthetic bedding.

At the age of 7, children who had been exposed to composite bedding were more than twice as likely to have recently experience wheezing and night wheezing compared with infants who had natural bedding.

There also a relationship between increased exposure to such bedding and more wheezing. In addition, when factors such as absence of bedroom carpeting and heating were present, say the investigators, “the association between type of bedding and wheezing was markedly exacerbated.”

Trevillian concluded that these findings “support current recommendations that low allergen bedding should be used for infants.”

SOURCE: American Journal of Public Health, December 2005.