By Robert Preidt
Health Day reporter
WEDNESDAY, December 3, 2014 (HealthDay News) – People with sleep apnea may have lower aerobic fitness levels, a new study suggests.
Sleep apnea causes obstruction of the upper airways by soft tissue in the back of the throat during sleep. This causes pauses in breathing and other symptoms, such as panting and snoring.
The research included 15 adults with moderate to severe obstructive sleep apnea and a comparison group of 19 adults with mild or no apnea. They cycled on a stationary bike at increasingly hard resistance levels – similar to climbing an increasingly steep hill – and continued until exhaustion.
On average, people in the sleep apnea group scored 14% lower on a test that measures the maximum amount of oxygen a person can absorb during strenuous exercise. This measurement is called VO2 max.
People with sleep apnea are more likely to be overweight or obese, and therefore less fit, the researchers noted. However, they found that people with sleep apnea had poorer aerobic capacity than those in the comparison group, even though they were the same body size.
Although this study found an association between lower oxygen uptake during activity and sleep apnea, it was not designed to prove that sleep apnea was the definitive cause of this difference.
The results of the study were published in the Nov. 15 issue of the Journal of Clinical Sleep Medicine.
“Encouraging patients to exercise more is part of the story, but it’s not the whole story,” said lead author Dr Jeremy Beitler, assistant clinical professor of pulmonary medicine and care intensive at the University of California, San Diego School of Medicine, said in a college press release.
âWe believe that sleep apnea itself causes structural changes in the muscles that contribute to their difficulty in exercising,â he added.
Researchers said measuring VO2 max could help identify patients with sleep apnea at increased risk for heart attack and stroke, which could encourage earlier treatment of sleep apnea. , which is underdiagnosed and often untreated.