January 9, 2014
News Review From Harvard Medical School -- Device May Improve Sleep Apnea
A new type of device may help people with sleep apnea, results from a small study suggest. Obstructive sleep apnea causes breathing to stop or become very shallow for brief periods. This occurs because of a blockage to the airway during sleep. Sleep apnea can cause a drop in blood oxygen and lead to a higher risk of heart disease. The new study included 124 people with obstructive sleep apnea. Each person received the new device, implanted by surgery. The device electrically stimulates a nerve that controls the tongue and muscles in the upper airway. The pulses are timed to the breathing cycle. They cause the tongue to move slightly forward and the upper airway to open. After a yearlong trial, episodes of apnea and drops in blood oxygen were reduced about 70%. Researchers then randomly divided the 46 people who had the best treatment response into 2 groups. One group had the devices turned off for a week. The other group turned them on at bedtime, as usual. Apnea episodes jumped sharply in the group that had the devices turned off. The New England Journal of Medicine published the study. HealthDay News wrote about it January 8.
By Robert H. Shmerling, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
Sleep apnea is a common -- and potentially dangerous -- condition.
Estimates suggest that it affects more than 12 million people in the United States. People with sleep apnea have episodes of apnea (when breathing stops) or hypopnea (unusually slow or shallow breathing) during sleep.
Sleep apnea also can affect your overall health. Many people may not realize this. The health effects of sleep apnea may include:
- Sleepiness during the day (which may contribute to motor vehicle accidents)
- Low blood oxygen
- Abnormal heart rhythms, heart failure and other heart and blood vessel problems
- High pressures around the arteries near the lung, a potentially serious condition called pulmonary hypertension
- A higher risk of insulin resistance (which can lead to diabetes) and early death
So, when I read about a new and effective treatment for sleep apnea, I wanted to learn more.
Current treatments can be effective. But they are hard to tolerate. The most common treatment is a tightly fitting mask worn at night. Air is continuously pumped through the mask. This creates air pressure that keeps the airways at the back of the throat open. The treatment is called continuous positive airway pressure, or CPAP.
Unfortunately, many people with sleep apnea remove the mask during sleep without realizing it. Some can't tolerate the mask because they find it so uncomfortable.
Other treatments include surgery to remove tissue at the back of the throat. However, it's not clear how effective these treatments are.
The New England Journal of Medicine just published a study on another approach to treating sleep apnea. It includes results from 124 people with sleep apnea who were treated with a surgically implanted "upper-airway stimulation device." This device sends electrical signals to a nerve under the jaw that pushes out the tongue. These movements are linked to certain points in the breathing cycle. This relieves blockage of the upper airway.
The study results suggested that this approach worked well. A year after the devices were implanted:
- Episodes of apnea or hypopnea decreased nearly 70%
- Episodes of decreased blood oxygen were also reduced by 70%
- Measures of quality of life (such as sleepiness) improved significantly
Serious problems caused by the surgery were rare and treatable.
A year after treatment, the researchers randomly assigned people who had improved with the surgery to have their device turned off for a week or to keep it on. The "device-on" group continued to have improvement in their sleep. But those in the "device-off" group got worse.
The results of this study are encouraging. But it's not yet clear how important these findings are. That's because the study:
- Was small
- Did not have an untreated comparison (control) group
- Excluded many people with sleep apnea, including those who had other lung or heart disease
- Used an invasive (surgical) treatment that might not be acceptable to all who have sleep apnea
- Was sponsored by the makers of the device
Still, this study may offer a new approach for people with sleep apnea who aren't improving with other treatments. Further refinements to airway stimulators might lead to more effective and less invasive treatments.
What Changes Can I Make Now?
The most important change you can make is to recognize sleep apnea and get treatment for it. Many people diagnosed with sleep apnea become aware of it only because a bed partner, roommate or family member observes spells of apnea or hypopnea.
Know the symptoms of sleep apnea. These include:
- Restlessness during sleep
- Loud snoring
- Awakening with a sensation of choking or gasping
- Excessive sleepiness or fatigue in the morning and/or during the day
- Sore or dry throat when awakening
- Headaches, especially in the morning
- Irritability or trouble concentrating
Sleep apnea is more common among:
- People who have family members with the condition
- People who are overweight or obese
However, the condition is not rare among women or people of normal weight.
Talk to your doctor if you have symptoms that suggest sleep apnea or if people have told you that you stop breathing at times during sleep. The device described in this latest research is still being tested, so it may not be available outside of a clinical trial. But there are other treatment options to consider, including loss of excess weight and wearing a mask that provides CPAP.
What Can I Expect Looking to the Future?
Considering the big impact this condition has on health and quality of life, you can expect the search for better treatments to continue. Obesity has increased dramatically in the United States. Because of this, and the increased awareness of sleep apnea, you can expect many more cases to be diagnosed in the coming years.
In the near future, we should have the results of larger studies of implanted upper-airway stimulators. If the findings are as positive as in this recent trial, these devices may become a common treatment for this common condition.