A key feature of idiopathic pulmonary fibrosis (IPF) is higher levels of damaging oxygen oxidants, or substances that oxidize other substances. These compounds trigger tissue scarring known as fibrosis.
Exercise can increase production of oxygen oxidants. In fact, exercise-triggered oxidative stress can increase muscle damage in IPF patients. At the same time, physical activity improves the disease’s symptoms and patients’ quality of life.
Although oxygen therapy is commonly recommended in IPF management, the subject of whether it should be used during exercise is controversial. Some studies have suggested that supplemental oxygen during exercise can help mitigate the shortage of oxygen that occurs during physical activity and prevent muscle damage. Other research has suggested that additional oxygen is not beneficial, and can even cause damage.
Australian researchers decided to investigate the effects of oxygen therapy during exercise. Their study was titled “Greater endurance capacity and improved dyspnoea with acute oxygen supplementation in idiopathic pulmonary fibrosis patients without resting hypoxaemia.”
The clinical trial (ACTRN12611001154998) covered 11 IPF patients who were randomly chosen to receive oxygen or compressed air during rest or an hour’s exercise.
They discovered that supplemental oxygen or air supply at rest did not change patients’ blood levels of inflammatory proteins, oxidative stress, or muscle-metabolism compounds.
The results were different during exercise. Oxygen therapy improved patients’ ability to exercise, prevented them from experiencing an oxygen shortage during workouts, and reduced their exercise-related breathing difficulties, a condition known as dyspnea.
Researchers also discovered that supplemental oxygen during exercise reduced what are known as xanthine blood levels. Xanthine is an enzyme that can generate reactive oxygen species that damage the body. Lower xanthine levels improve muscle metabolism, reducing muscle damage.
The team cautioned that components besides xanthine can be involved in such complex mechanisms. That means further studies should be done on the relationship between supplemental oxygen and improved muscle metabolism, the researchers said.
“We found that oxygen improved exercise performance, strengthening previous findings, and we provided the first evidence that oxygen effectively reduces exertional dyspnoea in IPF,” the team wrote. “Supplemental oxygen may facilitate improved skeletal muscle metabolism through increased oxygen delivery. Supplemental oxygen may therefore be a beneficial adjunct to exercise training in IPF, optimizing physiological improvements through increased endurance training time.”