Breath of Fresh Air: Feature Articles

Lungs are lungs, and bronchial tubes are bronchial tubes. Can there be any differences in asthma between men and women just because of gender difference?

The answer appears to be a definite, YES. Consider the following:

• before the age of puberty, more boys than girls have asthma, but after puberty asthma is more common among women than men;
• for some women asthma gets predictably worse around the time of each menstrual period;
• pregnancy can have a major influence on the course of asthma; sometimes asthma gets much worse during pregnancy, sometimes it improves dramatically;
• in most studies of severe asthmatic attacks, women outnumber men in the frequency of emergency department visits and hospitalizations for asthma; and
• after the menopause, women taking hormone replacement therapy more often develop the new onset of asthma than women who do not.

Pregnancy, menstrual periods, and hormone replacement therapy may all influence asthma in women.

Many observations have been made about gender differences in asthma, but few explanations for these differences are available. It is likely -- but unproven -- that the reproductive hormones such as estrogen and progesterone influence the function of bronchial tubes, perhaps by affecting how the bronchial muscles behave, perhaps modifying the allergic inflammation of the airways. There may be differences between men and women in terms of their genes relevant to asthma or in terms of how these genes get expressed. At the same age and height, women have smaller lungs and narrower bronchial tubes than men. Perhaps this slight difference partially accounts for a greater tendency toward significant airway narrowing with compromise of airflow in asthmatic women than in asthmatic men.

Differences in asthma between men and women may be due to:

Biologic differences;

Alternatively, maybe the differences in asthma between men and women come not from our inherited or biologic differences but from the environments in which we live. In our culture it remains true that women overall spend more time in the home environment than do men. If the home is the source of allergens — such as the dust mite, cockroaches, and furry or feathered animals — that cause or exacerbate asthma, then women may have greater exposure to these inciters and triggers of asthma.

Environmental differences; or

One further possibility relates not to how asthma may act differently in the male and female bodies but rather to how men and women may respond differently to their disease. Women may be more likely to be aware of their symptoms of asthma, be more likely to report them to a physician, and be more likely to seek medical attention during an asthmatic attack. Like cultural differences, gender differences influence how we view our life experiences and what health beliefs we hold. For instance, women more than men may go to a doctor when suffering with a flare of asthma. This difference could contribute to the observation that rates of emergency department visits and hospitalizations are more common among women than among men.

Like all generalizations about gender differences, those made regarding asthma are filled with innumerable exceptions. Many women note no changes in symptoms around their menstrual periods, have unchanged asthma during a pregnancy, and note no influence of hormone replacement therapy on their asthma. Many men have severe asthma and receive emergency department or in-hospital medical care when necessary. Generalities must be watched closely, lest they stereotype behaviors, attribute disease characteristics too quickly to factors over which we have no control, or separate people rather than bring them closer together.

Still, real differences can teach us a lot about asthma. If we can understand how and why asthma is different for men and women, we can use that knowledge to improve asthma care for everyone. Right now we are at the beginning stages of understanding: finding how we are different and how we are the same.