Posted on 01/12/2020 9:06:30 PM PST by ConservativeMind
A new study led by Columbia University Medical Center (CUMC) researchers has found that leptin, a hormone that plays a key role in energy metabolism, fertility, and bone mass, also regulates airway diameter. The findings could explain why obese people are prone to asthma and suggest that body weight-associated asthma may be relieved with medications that inhibit signaling through the parasympathetic nervous system, which mediates leptin function.
"Our study started with the clinical observation that both obesity and anorexia can lead to asthma," said Gerard Karsenty MD, PhD. "This led us to suspect that there must be a signal coming from fat cells that somehow affects the lungs -- directly or indirectly." The most likely candidate was leptin, a protein made by fat cells that circulates in the bloodstream and travels to the brain.
Extensive evidence shows that obesity can cause narrowing of the airways (bronchoconstriction). When obesity develops in people with asthma, it exacerbates the breathing disorder. The current study was designed to elucidate the genetic and molecular bases of the relationships among obesity, airway diameter, and lung function.
Through mouse studies, the researchers showed that abnormally low or high body weight and fat mass results in bronchoconstriction and diminished lung function. Next, they showed that leptin increases airway diameter independently of, and at a lower threshold than, its regulation of appetite.
Leptin affects the airways by decreasing the activity of the parasympathetic nervous system, a branch of the autonomic nervous system. The researchers also showed that regulation of airway diameter occurs regardless of local inflammation in the bronchi.
"The therapeutic implication is that it may be possible to correct asthma in obese people with drugs that inhibit parasympathetic signaling -- and thereby increase leptin-related brain signaling," said Dr. Karsenty. Such drugs are already available. One is tiotropium bromide.
(Excerpt) Read more at sciencedaily.com ...
Obese people may also have higher rates of cancer.
The cancer cells probably like all that fat floating in the blood to grow faster.
Maybe that is why I am heavy, from lack of exercise?
And people with an obese tongue are more likely to have sleep apnea.
Hmm. I had assumed it was chronic inflammation from poor diet and the obesity itself.
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