A novel study has for the first time detected significant accumulations of fatty tissue in airway walls of obese and overweight people. The new research suggests these fat accumulations could explain why overweight individuals are at higher risk of respiratory disease and asthma.
"Being overweight or obese has already been linked to having asthma or having worse asthma symptoms,” explains Peter Noble, co-author on the new research from the University of Western Australia. “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.”
The new study hypothesized a relationship between excessive adipose, or fatty, tissue within a person’s airway walls, their body mass index, and respiratory disease. Post-mortem lung tissue from 52 subjects was closely studied and a direct correlation was found between increasing body mass index and fatty tissue accumulation in a person’s airways.
“We've found that excess fat accumulates in the airway walls where it takes up space and seems to increase inflammation within the lungs,” says Noble. “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 study is certainly small, so further research is necessary to understand how clinically relevant these fatty accumulations are to respiratory diseases, but the implications of the discovery are fascinating. Thierry Troosters, president of the European Respiratory Society, says the research suggests certain physiological changes to a person’s airways caused by fatty accumulations mean weight loss advice to overweight patients with asthma could significantly improve treatment outcomes.
"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,” says Troosters, who did not work on this particular study. “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.”
The next big challenge for the researchers is to find a way to measure fatty tissue in the lungs of living subjects. This will help affirm the findings of this study, and offer insight into whether weight loss therapies can help reduce these fatty lung accumulations.
The new research was published in the European Respiratory Journal.
Source: European Respiratory Society
