Researchers have long wondered why asthma is significantly more common in women than in men. This disparity is especially striking because the reverse is true before puberty. As a result, scientists have been curious to see if sex hormones have an impact.
How Sex Hormones Affect Airways:
The investigators focused on a type of white blood cell called ILC2 that is involved in airway inflammation (Cephus et al, Cell Reports, Nov. 28, 2017). People who had asthma had many more ILC2 cells than those who did not. (ILC2 stands for group 2 Innate Lymphoid Cell.)
The Effects of Testosterone, Estrogen and Progesterone:
The sex hormones testosterone, estrogen and progesterone are usually thought of with respect to reproduction. They also have a role to play in immunity and inflammation, however. Research in cell cultures found that testosterone prevented ILC2 cells from making a protein that triggers inflammation. The female hormones estrogen and progesterone did not change production of this pro-inflammatory protein.
Very likely there is much more to the asthma story than just testosterone, but these results suggest that the best treatment might vary based on the sex of the patient.
Another possible contributor to airway inflammation is infection. You can learn more about that in Dr. David Hahn’s book, A Cure for Asthma? What Your Doctor Isn’t Telling You–and Why.