FRIDAY, Nov. 4 (HealthDay News) -- Hormone fluctuations may explain why women have higher asthma rates than men, according to reports presented Friday at the annual meeting of the American College of Allergy, Asthma and Immunology, in Anaheim, Calif.
"Women between the ages of 20-50 years are more than three times as likely as men to be hospitalized with asthma despite comparable spirometry. Studies have demonstrated a relationship between asthma and the menstrual cycle, with 46 percent of women's hospital admissions perimenstrual, and up to 40 percent of women having premenstrual asthma symptoms," Dr. Nancy K. Ostrom, of the University of California and the Allergy & Asthma Medical Group and Research Center in San Diego, said in a prepared statement.
"As many as 8 percent of pregnant women have asthma. Women with asthma who are pregnant or are planning a pregnancy face unique concerns about controlling their asthma symptoms and regarding the safety of medications," Ostrom said.
She added that smoking, obesity and a sedentary lifestyle are other factors that may contribute to differences in asthma rates between women and men.
Dr. Joan Gluck of the Florida Center for Allergy and Asthma Care also discussed the link between hormones and asthma in women.
"When we look at the reproductive phases of a woman's life cycle, we find in children under age 12, asthma is more common in boys than in girls. Around puberty the ratio changes, with asthma becoming more common in girls than in boys," Gluck said in a prepared statement.
"Women with asthma experience more symptoms during their premenstrual and menstrual weeks with peak symptoms two to three days before menses. Many are not aware of this pattern, and keeping a diary of their symptoms is very helpful," said Gluck, who added that most premenstrual asthma patients respond to standard therapy.
She also noted that oral contraceptives have been shown to have a beneficial impact on asthma.
"Nonasthmatic women on oral contraceptives have a higher total lung capacity. Airways are more stable in women with asthma who take oral contraceptives, and several small studies have shown their asthma does improve," Gluck said.
The U.S. National Women's Health Information Center has more about asthma.