Hormonal clue to higher asthma rates in women

Nov 7 2005

According to experts hormone fluctuations resulting from life cycle changes are a factor in higher rates of asthma, more frequent emergency department visits, and higher hospital admission rates in women than in men.

The researchers say that in a study on asthma incidence and mortality, in relation to premenstrual and perimenstrual cycles, they found that women between the ages of 20-50 years were more than three times as likely as men to be hospitalized with asthma despite comparable spirometry.

According to Nancy K. Ostrom, M.D., at the University of California and the Allergy & Asthma Medical Group and Research Center in San Diego, their study shows that 46 percent of women’s hospital admissions were perimenstrual, and up to 40 percent of women were having premenstrual asthma symptoms.

Ostrom says that as many as 8 percent of pregnant women have asthma and face unique concerns about controlling their asthma symptoms and regarding the safety of medications.

According to Dr. Ostrom obesity, sedentary lifestyle and smoking are other factors potentially contributing to the gender difference in asthma morbidity and mortality.

Other experts agree; Joan Gluck, M.D., at the Florida Center for Allergy and Asthma Care in Miami says that when the reproductive phases of a woman’s life cycle are examined, in children under age 12, asthma is more common in boys than in girls.

However around puberty the ratio changes, with asthma becoming more common in girls than in boys.

Asthma is three times more common in women than in men.

It seems that women with asthma experience more symptoms during their premenstrual and menstrual weeks with peak symptoms two to three days before the period starts, and as many are not aware of this pattern, keeping a diary of their symptoms is very helpful, says Gluck.

Most premenstrual asthma patients respond to standard therapy.

Oral contraceptives have been shown to have an impact on asthma.

It seems the airways are more stable in women with asthma who take oral contraceptives, and several small studies have shown their asthma does improve.

A correlation with higher asthma rates has also been noted in menopause and perimenopause, occurring prior to final menstrual cycle.

As far as Hormone replacement therapy (HRT) is concerned different effects on asthma for different groups have been noticed.

While nonasthmatic women taking HRT appear to have a higher risk of developing asthma, asthmatic women significantly improve on HRT, with studies showing as much as a 35 percent reduction in the use of inhaled steroids, says Dr. Gluck.

According to Michael Schatz, M.D., M.S., at Kaiser-Permanente Medical Center in San Diego, asthma complicates up to 8 percent of pregnancies and may increase the risk of perinatalcomplications.

When women with asthma become pregnant, a third of the patients improve, one third worsen, and the last third remain unchanged.

The asthma is most likely to appear during the weeks 24 to 36 of gestation, with only a small minority of patients (20 percent or fewer) becoming symptomatic during labor and delivery.

Those with more severe asthma prior to pregnancy may be more likely to worsen during pregnancy, and uncontrolled asthma may increase the risk of perinatal mortality, low birth weight infants, preterm births and preeclampsia.

Management of asthma during pregnancy includes assessment and monitoring; reduction of triggers, patient education and pharmacologic therapy.

Optimal management of asthma during pregnancy minimizes the risks, and improves maternal and fetal outcomes.

Poor asthma control is the major risk to the health of the mother and fetus.

According to recent National Asthma Education and Prevention Program guidelines, ICS are recommended as the controller therapy of choice for all levels of persistent asthma during pregnancy.

Dr. Schatz says that although the outcome of any pregnancy can never be guaranteed, most women with asthma and allergies do well with proper medical management.