Hormone Supplements, Asthma May Be LinkedFeb 23, 2004 | AP
The study was not as rigorous as landmark research halted in 2002 after more hormone users developed heart problems and breast cancer than women given dummy pills. And the overall risk of developing asthma late in life is slim.
Still, the findings might be something women will want to consider when debating whether to take hormones for hot flashes and other menopause symptoms, said lead researcher Dr. R. Graham Barr of Columbia Presbyterian Medical Center.
The findings appear in Monday's Archives of Internal Medicine.
"For women who have severe asthma that develops later in life, they may want to consider a trial of stopping hormone replacement therapy to see if this alleviates their condition," Barr said.
The study was part of the Nurses' Health Study by Harvard's Brigham and Women's Hospital and involved more than 70,000 women in their 40s and older. They were questioned about hormone use and any diagnosis of asthma. They were followed for about 10 years, until 1998.
During that time, 342 women developed asthma. Current users of either estrogen alone or estrogen plus progestin supplements were about twice as likely to develop asthma than nonusers.
The increased risk was found mainly among current users, not past users, suggesting that stopping hormone treatment can even the odds, Barr said.
The study follows the government's landmark Women's Health Initiative study, which reported the link with heart problems and breast cancer and led many doctors to recommend limiting hormone treatment to low-dose, short-term use for menopause symptoms.
WHI researcher Jennifer Hays of Baylor University questioned whether hormones cause asthma and said there are other possible explanations for the link. It might be that something about the lifestyles of hormone users puts them at increased risk for asthma, Hays said.
The researchers acknowledged that women who take prescription hormones might be more likely to be diagnosed with asthma simply because they might have more doctors' visits than nonusers. But they also found an increased asthma risk among hormone users who had few doctors' visits.
Asthma involves inflammation that constricts muscles in the airways, causing attacks of wheezing and shortness of breath. An estimated 20 million Americans, including 14 million adults, are affected.
Barr said the exact relationship between hormones and asthma needs further study.
But estrogen tends to make cells retain more fluid, which might narrow lung airways, he said. Also, some data have shown that hormone supplements can increase levels of certain inflammatory markers in the blood, which might also affect asthma risk, he said.