For some women on hormone replacement therapy (HRT), the risk of severe asthma attacks may increase, according to a new study led by Dr. Klaus Bonnelykke from the Danish Paediatric Asthma Centre in Copenhagen. Presented Tuesday at the European Respiratory Society meeting in Amsterdam, the study analyzed data from over 23,000 women and found that, after accounting for factors such as smoking and body mass index, those using HRT were 30 percent more likely to be hospitalized for asthma. For women using HRT for longer than 10 years, the risk went up to 50 percent. In addition, the study demonstrated a dose-response effect between length of HRT use and increased risk of asthma attacks.
This research comes on the heels of findings from a French study last year that looked at 58,000 women on HRT and found that 54 percent developed asthma.
But as Dr. Bonnelykke says, his current research focused on women who were using either pure estrogen or combined products; therefore, more research on the association between female sex hormones and asthma is warranted.
If these results are borne out in future studies, then asthma is a risk factor that women on HRT should be made aware of, says ACSH's Dr. Ruth Kava.