New Risk Factor for Irregular Periods
Researchers surveyed more than 6,000 women from five Northern European countries about their menstrual cycles and history of allergies, asthma, or other respiratory problems from 1999 to 2001. The study appears in the current issue of Thorax.
Overall, the results showed that about one in four women had irregular periods.
After adjusting for other risk factors, researchers found that allergy and asthma were significantly more common among women with irregular periods than those with regular cycles.
For example, women under age 43 with irregular periods were:
- Around 50% more likely to have asthma or asthma attacks.
- Nearly twice as likely to have asthma preceded by hay fever.
- Nearly 30% more likely to have hay fever or nasal allergies.
Researchers say the same trends were seen whether or not the women with asthma symptoms were treated by medication. This suggests that asthma medications are not related to the increased irregular period risk.
In women aged 43 and older -- an age when irregular periods usually signal the normal approach of menopause -- no association was found with new-onset asthma.
Asthma and allergies appear to be associated with the pathological condition underlying irregular periods, the researchers say.
They say the results should add to the understanding of asthma's origins and suggest that common factors may play a role in both irregular periods and asthma/allergy.
The study also showed that among younger women, irregular periods were more common among women who weighed the most or were the shortest or tallest. Among older women, irregular periods were linked to smoking and the start of menopause.