Posted by Brigham and Women's Hospital May 21, 2013
Leg movements that follow pauses in breathing during sleep might be a predictor for heart disease in older men with moderate to severe obstructive sleep apnea, according to research by scientists in the Division of Sleep Medicine at Brigham and Women’s Hospital (BWH).
The National Sleep Foundation reports that more than 18 million adults in the U.S. have sleep apnea – a disorder in which breathing is repeatedly disrupted during sleep. Obstructive sleep apnea occurs when muscles in the airway, such as the tongue, block breathing during sleep.
Previous studies have shown that obstructive sleep apnea is a risk factor for high blood pressure and heart disease. A BWH research team led by Dr. John Winkelman wanted to investigate whether respiratory-related leg movements (RRLM), muscle movements in the leg that follow a sleep apnea episode, may further contribute to heart disease risk.
Dr. Winkelman and his team examined data from 636 men in the Osteoporotic Fractures in Men (MrOS) Study, with a mean age of 81 years, who reported moderate to severe sleep apnea and leg movements on patient questionnaires. They found that risk for heart attacks and other cardiovascular events increased by 26 percent for every 20 to 25 such leg movements reported per night.
“It is not clear from this data whether the increased risk is due to leg movements being markers of more severe sleep apnea episodes, or whether leg movements are producing greater swings in blood pressure, and therefore, a higher risk for cardiovascular disease events,” said Winkelman. “We plan to do more research to answer such questions.”
Though the answers to these questions are still unknown, the data opens the door to new possibilities for combating heart disease in the future.
“Easily identified features in sleep may be important in predicting future risk of heart disease in those with sleep apnea,” said Dr. Winkelman. “If confirmed, we could target aggressive treatment for those with sleep apnea at highest risk of heart disease. Further, we need to see if quieting such leg movements could possibly reduce risk of heart disease for people with sleep apnea.”
More information about sleep and sleep research:
- BWH Sleep Disorders Service
- Making Headway on Beta-Blockers and Sleep
- Sleep Research: Is the Night Shift Bad for Your Health?
- Why Can’t We Stay Asleep as We Get Older?