Medical Center Research May Explain Why Obese People Have Higher Rates of Asthma

Findings suggest that therapies that increase leptin-signaling may relieve asthma in obese people. New York, NY - 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. The study, conducted in mice, was published in the online edition of the journal Cell Metabolism . "Our study started with the clinical observation that both obesity and anorexia can lead to asthma," said Gerard Karsenty MD, PhD , professor and chair of genetics and development and professor of medicine at CUMC, and lead author of the study. "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).