Scientists have discovered why asthma often affects women than men

© Fotolia / IlikeАэрозольный inhaler for patients with asthmaScientists have discovered why asthma often affects women than men© Fotolia / Ilike

. Asthma affects more often women than men, for the reason that their hormones do not block inflammation and slow the mucus lungs, as does testosterone, according to a paper published in the journal Cell Reports.

«When we started these experiments, we were confident that in the development of asthma is to blame estrogen, accelerating the development of inflammation, and not slowing them down, as does testosterone. To our surprise, it turned out that a key role in all these processes plays only a male hormone,» said dawn Newcomb (Newcomb Dawn) from Vanderbilt University in Nashville (USA).

Asthma is a chronic respiratory inflammation, which is manifested in asthma attacks of varying strength and duration. They occur because of disorders in the immune system cells that cause inflammation in the breathing passages and causing them to narrow. According to the world health organization, currently suffer from asthma 300 million people, and every decade the number of patients increases in half.

One of the hallmarks of asthma is the fact that most of its victims is the fairer sex. As shown by recent observations of the French and Spanish doctors, women suffer from asthma about twice as often as men and they often affect the most serious form of the disease than men.

Newcombe and her colleagues uncovered one of the main reasons for this, studying that, how was organized lung tissue from asthmatics and healthy men and women, as well as in mice suffering from similar problems.

As shown by these observations, the lungs of all asthmatics were United by one thing in common – they contained a large number of so-called lymphoid cells of the second type, one of the key components of the innate immune system. These cells are responsible for starting the inflammatory response in cases when in the lungs or in other parts of the body start to breed bacteria.

These cells, according to scientists, was significantly greater in lungs of female asthmatics and female mice of that has led scientists to test how their behavior is influenced by sex hormones, including estrogen and testosterone.

Much to the surprise of biologists, the female hormones had no effect on the behavior and development of these cells, their number and activity level in the lung tissue remained on the same level when adding any quantities of estrogen and progesterone. On the other hand, the addition of even small quantities of testosterone and its derivatives «pacified» lymphoid cells – they ceased to proliferate and cause inflammation.

Such differences in action of hormones on the immune system, as the biologists can explain why women are twice as likely to suffer from asthma than men. On the other hand, Newcomb and her colleagues emphasize that the development of this disease involves many other factors, some of which can also be associated with these differences.