A study by Australian researchers has found fatty tissue in the lungs and airway walls of overweight people. It’s the first time fatty deposits have been spotted in the lungs and the researchers believe that the build-up may be linked to asthma. The research has been published in the European Respiratory Journal.
Respiratory problems such as asthma have long been linked to those who are overweight, but the reason for this has never been clear. Scientists have speculated that extra pressure on the lungs due to weight or additional inflammation in the body was the reason for the connection, but that has never been definitively proven. Now, the study’s authors are pointing to fat accumulation changing the structure of the airways in a way that raises asthma risk for overweight individuals.
Asthma is a common condition which causes the small tubes inside the lungs to become inflamed. As the airways constrict, it makes it harder for the person to breathe. Common triggers include allergies, dust, air pollution, exercise, and infections, and cases are generally treated with an inhaled medication designed to reduce the inflammation.
For this latest study, researchers with Sir Charles Gairdner Hospital and the University of Western Australia in Perth analyzed 52 post-mortem lungs which had been donated to the Airway Tissue Biobank. Out of those, 15 had no reported asthma, 21 had reported asthma but died of something else, and 16 had died of asthma itself.
Nearly 1,400 airways were dyed and examined under the microscope for any fatty tissue. The amount of fatty tissue was then compared to each person’s BMI when they had been alive. The researchers found that a higher BMI correlated with a higher amount of fatty tissue in the lungs.
The exact mechanism that’s causing the fat to appear in the airways isn’t clear. More study is needed to determine what is causing the fat to deposit in the lungs and whether weight loss could reverse the accumulations, thereby reducing the person’s asthma risk.