Environmental Factor, February 2006, National Institute of Environmental Health Sciences
Exploring Gender Differences in Lung Function
By Colleen Chandler
Research in Darryl Zeldin's lab focusing on gender differences in lung function and response to environmental agents raised some interesting questions for researchers within the Laboratory of Respiratory Biology.
Analyses of data from the National Health and Nutrition Examination Survey III, conducted between 1988-1994, and the National Health Interview Survey in 2001, show that asthma is more prevalent in males during childhood and adolescence, but more prevalent in females from about age 20 until very old age, when men, again, have a higher rate of asthma than women.
The numbers, Zeldin said, "reek of hormonal influence." He presented some research findings Dec. 16 at NIH for the Women's Health Special Interest Group.
The age of decline for women seems to coincide with the onset of menopause, suggesting a protective quality of estrogen. Around age 80, the higher prevalence of asthma switches back to males. Analyses of other data on women who take birth control or hormone replacement therapy seem to confirm the protective effect of estrogen, Zeldin said.
However, some of the research done in Zeldin's groups suggests androgen provides protection for male mice. Asthma is a complicated disease with many contributing factors, including environmental factors and genetics, Zeldin said. It appears that sex hormones are important in both mice and humans, but there is yet much to be discovered about their specific roles and mechanisms, he said.
Gender differences in lung function and airway responsiveness in mice may provide a means to better understand gender differences in humans, Zeldin said. The basic mechanisms underlying gender differences in lung function and airway response to environmentally relevant stimuli are poorly understood, he said.
Overall and including both genders, 11 percent of people will have asthma during their lifetimes. That's 30.8 million people, of which more than 4,200 will die, according to 2002 data. Yet, very little research has been done on gender differences in asthma.
A videocast of Zeldin's presentation on Dec. 16 can be found by going to http://videocast.nih.gov/PastEvents.asp?c=998.