Fat Collects in Lungs, Raising Asthma Risk

FRIDAY, Oct. 18, 2019 (HealthDay News) -- Excess weight is hard on the heart, but new research shows it may also harm your lungs.

The study found that higher amounts of fat collect in the airways of overweight and obese people, which may help explain why they're more likely to have wheezing and asthma.

In the study, the investigators analyzed lung samples donated by 52 people for research after their death. Of those, 16 died of asthma, 21 had asthma but died of other causes, and 15 had no asthma.

The findings showed, for the first time, that fatty tissue accumulates in the walls of airways and that the amount of fat in airways increases with body mass index (an estimate of body fat based on weight and height).

The researchers also found that higher levels of fat change the normal structure of airways, resulting in lung inflammation, according to the report published Oct. 17 in the European Respiratory Journal.

"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," explained study co-author Peter Noble. He's an associate professor at the University of Western Australia in Perth.

"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," Noble said in a journal news release.

"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," Noble added.

Thierry Troosters, president of the European Respiratory Society, 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."

Troosters, who was not involved in the study, added, "We need to investigate this finding in more detail and particularly whether this phenomenon can be reversed with weight loss. In the meantime, we should support asthma patients to help them achieve or maintain a healthy weight."

More information

The U.S. National Heart, Lung, and Blood Institute has more on asthma.