Nevertheless, it has been known for a long time that there was some sort of link between obesity and asthma. A new study led by Columbia University Medical Center not only confirms this theory, but has also been able to put forward exactly what the link might be.
The researchers have discovered that a hormone called leptin, which was known to be important to the body’s bone mass, fertility and energy metabolism, also controls the diameter of airways in the lungs. The findings could explain why obese people are more likely to develop asthma, but also suggest that weight-related asthma could be relieved with medication that regulates the body’s leptin.
There is a wealth of evidence that suggests obesity can cause the airways of the lungs to narrow; this is known as bronchoconstriction. When obese people also develop asthma, this bronchoconstriction can make symptoms worse and give the asthmatic person even more breathing difficulties.
The study was conducted on obese, asthmatic mice. The researchers showed that obese mice suffered from bronchoconstriction and weaker lungs. They also showed that leptin regulates the diameter of airways regardless of its other functions. When the mice were then treated with medication that would inhibit leptin-signalling the researchers discovered that while lung inflammation did not reduce, the lungs function far better and that the asthma symptoms were virtually gone.
The study showed that, at least in mice, weight-related asthma could be relieved by using medication that stops leptin-signalling. While the lungs remain inflamed, the airways are able to open wider allowing the patient to breathe more easily.