HRT Raises Asthma Risks Among Older Women
Menopausal Hormone Therapy May Increase Asthma in Postmenopausal Women
Feb. 23, 2004 -- Taking menopausal hormone therapy may increase the risk of asthma among postmenopausal women, according to new study.
Researchers found postmenopausal women on estrogen alone or estrogen plus progestin were more than twice as likely to develop asthma than women who never used hormones.
But the same study shows that menopausal hormone therapy does not increase the risk of chronic obstructive pulmonary disease (COPD).
Researchers say that a person's risk of developing asthma varies by age and sex. Asthma rates are higher among women than men until about age 50, when the asthma rates among men and women become about equal.
HRT May Raise Asthma Risks
In the study, researchers used data from the Nurse's Health Study, which involved 121,700 registered female nurses who were between 30 and 55 years old when the study began in 1976. The participants were mailed questionnaires every two years that included questions on hormone use, medical history, diet and lifestyle, and other factors.
From 1988 to 1996, the participants were also asked about new asthma and COPD diagnoses.
Researchers found that current use of estrogen was associated with a 2.29 times higher risk of asthma compared with women who never used hormones. A similar increase in risk was found among women who used estrogen plus progestin HRT.
But the rates of newly diagnosed COPD were similar among HRT and non-HRT users.
The results appear in the Feb. 23 issue of The Archives of Internal Medicine.
The study also shows that the increased rates of asthma associated with menopausal hormone therapy leveled off and returned to normal within four years after hormone therapy was discontinued.
Researchers say it's unclear exactly how current use of HRT affects asthma risks. But they say estrogen is known to have a variety of pro- and anti-inflammatory effects within the body that may negatively affect lung function.