A new research suggests an association between irregular menstrual cycles and a heightened risk of Asthma and hay fever in younger women. The finding adds weight to evidence suggesting that female hormones might have a role in the development of asthma and allergies.

Previous reports have suggested a disturbance in sex hormone levels among women with asthma. However, it is unclear if asthma and allergy were linked to irregular periods in a general population.

To investigate, Dr. C. Svanes of Haukeland Hospital,  Norway and colleagues surveyed more than 6100 non-pregnant women living in Denmark, Estonia, Iceland, Norway, and Sweden. The subjects were followed for 8 years.

In women between 26 and 42 years of age, irregular menstruation raised the risk of asthma and hay fever by 54 percent and 29 percent, respectively. Moreover, irregular menstruation nearly doubled the risk of asthma preceded by hay fever.

In older women, the associations were less clear and irregular menstruation was not significantly tied to the onset of asthma, the investigators point out.

“This study is the first to show that asthma and allergy are related to irregular menstrual periods,” the authors state. “These findings raise the question of whether women with asthma have a higher incidence of subfertility problems as indicated in a previous study.”

SOURCE: Thorax June 2005.