Lab Mouse

Why Do People with Obesity Have Higher Rates of Asthma?

The association between obesity and asthma is not well understood. To understand potential reasons at a cellular level, researchers at the Columbia University Medical Center designed a study to explain the genetic and molecular relationships among obesity, airway diameter, and lung function. They found that leptin, a hormone that plays a key role in obesity and energy metabolism, also regulates airway diameter, which could explain why people with obesity are prone to asthma.

It was through mouse studies that the researchers showed that abnormally low or high body weight and fat mass results in bronchoconstriction and diminished lung function. After that discovery, they identified that the hormone leptin increases the airway diameter independently of its regulation of appetite.

Gerard Karsenty and colleagues found that leptin affects the airways by diminishing the activity of the parasympathetic nervous system, a branch of the autonomic nervous system not usually associated with leptin. The researchers also showed that regulation of airway diameter occurs whether or not there is local inflammation in the bronchi.

The researchers then conducted two additional experiments to establish if these findings might have some bearing on asthma therapy. These experiments demonstrated the ability to cure obesity-related asthma without affecting inflammation in mice. “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 Karsenty.

Click here to read the summary of this study in Science Daily and click here to read the study abstract in Cell Metabolism.

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