Postmenopausal women who used hormone therapy are at increased risk for developing asthma, says a study in the Feb. 23 issue of the Archives of Internal Medicine.
But hormone therapy does not increase the risk of chronic obstructive pulmonary disease (COPD), the study adds.
Researchers at Brigham & Women's Hospital in Boston analyzed data from the Nurse's Health Study, which enrolled 121,700 married female registered nurses, aged 30 to 55, in 1976. Participants in the Nurse's Health Study were sent questionnaires once every two years. The nurses were asked about their medical history, diet and lifestyle, exercise and hormone use.
From 1988 to 1996, the nurses were sent follow-up questionnaires that asked them about new asthma and COPD diagnoses.
In this new study, researchers found current use of estrogen alone was associated with a 2.29 times greater risk of asthma. Women who used estrogen plus progestin had a similar increased rate of newly diagnosed asthma.
"Postmenopausal hormone use was associated with an increased rate of newly diagnosed asthma, but not newly diagnosed COPD. Female reproductive hormones may contribute to the onset of asthma among adult women, but do not appear to hasten the development of COPD," the study authors write.