Like many other chronic illnesses such as arthritis and multiple sclerosis, women are at a far greater risk of developing asthma than men. In fact, a new study has revealed that women are twice as likely as men to have the inflammatory disease. The gender difference may be, after all, caused by the effects of some sex hormones on our lungs. Researchers from both John Hopkins and Vanderbilt University discovered that testosterone, the male sex hormone, could suppress the immune cell related to asthma symptoms, like inflammation and extra mucus production. This research into both human and mouse cells, conducted by a team of experts, was published in a recent edition of the Cell Reports journal.
When they began the study, the initial thought was that female sex hormones would promote inflammation more, when compared with the inhibiting effect of testosterone, says senior researcher Dawn Newcomb of the Vanderbilt University Medical Center. Newcomb mentioned that she was quite surprised to know that the male sex hormone was much more active in reducing inflammation than any effect associated with the female sex hormones. Based on previous research, pre-pubescent boys are 1.5 times more likely than their female counterparts to have asthma. However, that pattern reverses itself after puberty. Adult women are twice as likely as men to develop the respiratory condition. This trend continues until the women reach menopause and, thereafter, the rates of asthma among women begin to decline.
Factors And Focus
Diverse factors have been known to control increased asthma symptoms. Some of these include viral infections, allergies, and the newly discovered activities of sex hormones. Newcomb and her team investigated human and rodent cells to shed more light on trends in the gender differences. They focused primarily on innate lymphoid cells type 2 or ILC2. These cell groups make cytokines, which are small proteins that usually cause inflammation and mucus production in the lungs, and make breathing harder.
The scientists collected and examined blood samples from volunteers with and without asthma and found that people with asthma had more of the group 2 innate lymphoid cells than those without asthma. Of this group, asthmatic women had more of the ILC2 cells than their men counterparts. Though rare, innate lymphoid group 2 cells are also found in mice lungs. They constitute just about 10,000 parts of the 10 million cells in the lung of a mouse. As noticed in humans, the researchers found that they were getting more cells from female mice than male mice. They used these cells in mice to study the impacts of sex hormones on ILC2 cells.
- When the team added female sex hormones - like estrogen and progesterone - to those ILC2 cells, there was no change in the cell's ability to make cytokines.
- On the other hand, when testosterone was introduced, they noticed that the hormone hindered cell expansion and also reduced the production of cytokines.
Newcomb wishes to promote further research to examine the effects of other sex hormones on asthma. She concluded that male sex hormones are probably the reason why there are more asthma cases in women than men. However, these sex hormones could be just one of many other important, yet hidden mechanisms regulating airway inflammation tendencies.
About The Author
Serene Hitchcock is a professional freelance writer, blogger and social media strategist from San Diego, California. She has been writing for several years in many forms and facets and is interested in arts, health, self-improvement, current events and the world we live in.