How you sleep could be affecting how you breathe. Medical researchers say they’ve found a link between the circadian rhythm—the body’s internal clock that is primarily responsible for regulating sleeping and waking cycles—and certain types of lung disease. This body clock is found in nearly all complex living things, even plants. In many mammals, including humans, it regulates how ready the lung is at various times throughout the day for the onslaught of airborne pollutants it must cope with.
While there is no immediate application of this research in preventing lung disease, researchers say it can be used to determine the best time to administer medication for respiratory problems, providing the greatest effectiveness while minimizing side effects. For example, inhaled long-acting beta agonists are often used for treating asthma. Unfortunately, these medications can present a risk of causing an asthma attack if care is not taken. By timing the dose based on when the patient’s body clock is getting the lungs ready to handle particulate mater in the air, it may be possible to get the same results with a lower dose of the medication, minimizing the risks.
Research is being done on other forms of treatment as well. Lung transplants are increasing as a last-ditch treatment for end-stage lung disease. Over the last 26 years, deaths as a result of these procedures have dropped by half as it is performed more frequently. However, the transplanted organs are rejected by the bodies of about one in three recipients, meaning the lung triggers an immune response. Other complications are also common, if often not fatal.
Rejection is a result of foreign matter—the donated lung—being implanted in the body. One solution is to do transplants without foreign mater using lungs constructed using the patient’s own stem cells. These are cells found in bone marrow that are in a base state, not specialized to work only in certain parts of the body. Being from the recipient’s body, stem cells do not draw the attention of the immune system, and they can be induced to grow into any form for which a structure can be provided. For lungs, research s ongoing into providing that structure, finding ways to create scaffolds for stem cells to cause them to grow into a fresh, undamaged replacement lung. An approach that has been explored with some success is to take a posthumously donated lung and replace the cells in it, row by row, with stem cells from a transplant patient, so the cells take the proper shape.