An October 2019 study by Sir Charles Gairdner Hospital in Perth, Western Australia, the University of Western and Australia European Respiratory Society studied, "the structure of the airways within our lungs and how these are altered in people with respiratory disease.”
Looking at samples of lung they, “spotted fatty tissue that had built up in the airway walls. We wanted to see if this accumulation was correlated with body weight."
The lead researcher said: "Being overweight or obese has already been linked to having asthma or having worse asthma symptoms. Researchers have suggested that the link might be explained by the direct pressure of excess weight on the lungs or by a general increase in inflammation created by excess weight.”
"This study suggests that another mechanism is also at play. We've found that excess fat accumulates in the airway walls where it takes up space and seems to increase inflammation within the lungs. We think this is causing a thickening of the airways that limits the flow of air in and out of the lungs, and that could at least partly explain an increase in asthma symptoms."
The team are looking for new ways to study and measure fatty tissue in the lungs. They want to confirm the relationship with respiratory disease and to find out whether the effect can be reversed by weight loss therapy.
Professor Thierry Troosters said, "This is an important finding on the relationship between body weight and respiratory disease because it shows how being overweight or obese might be making symptoms worse for people with asthma. This goes beyond the simple observation that patients with obesity need to breathe more with activity and exercise hence adding to their ventilatory burden. The observation points at true airway changes that are associated with obesity.”