DREAD OF NIGHT
As Americans’ waistlines continue to grow, so does the number of people who aren’t getting a good night’s sleep.
About 2% of women and at least 4% of men suffer from obstructive sleep apnea, a condition in which the airway collapses and blocks breathing for 30 seconds or even up to a minute or two. The brain senses that it isn’t receiving enough oxygen and sends a signal to the person to wake up. The awakenings are brief enough that people usually are not aware of them, but sleep is disrupted continually throughout the night, leading to daytime fatigue and drowsiness.
Sleep apnea -- a Greek word meaning “without breath” -- used to be a largely unrecognized condition, but the diagnosis is becoming much more common. The incidence rises with age: Experts estimate that it affects about 40% of people ages 65 and older. In women, the prevalence rises steeply after menopause. And as people get older, the throat muscles become more prone to collapse.
But age isn’t the only factor. Being overweight more than doubles your risk of having sleep apnea, says Dr. Lawrence Epstein, chief medical officer at Sleep HealthCenters, a network of clinics based in Brighton, Mass. And the number of people being treated for the condition is climbing along with rising obesity: a 2005 study in the Journal of Clinical Sleep Medicine found that the average weight of women referred to sleep centers for treatment of a breathing disorder had increased by nearly 10% over a nine-year period and the average weight of men rose almost 5%.
In children, sleep apnea was traditionally associated with enlarged tonsils and adenoids or skeletal abnormalities, which can constrict the airway. But doctors are finding that more children are being treated for sleep apnea as a result of being overweight. Dr. David Gozal, a pediatric sleep specialist at the University of Chicago, says the percentage of obese children being treated for sleep apnea in his program has increased from 23% in 1995 to more than 57% now.
“We’re now seeing it in young teens and even kids in the 7- to 9-year age range,” says Dr. Meir Kryger, the director of Sleep Medicine Research and Education at Gaylord Hospital in Wallingford, Conn. Kryger says he has treated children as young as 4 for obstructive sleep apnea related to weight.
The problem is worrisome, and not only because getting a good night’s sleep is critical for concentration and alert functioning at school, on the job and while driving. Sleep apnea also puts people at greater risk of heart disease, stroke, high blood pressure and diabetes.
When a blocked airway prevents oxygen from entering the body, blood vessels constrict and blood pressure rises as much as 25% to 30%, Epstein says. The activation of the sympathetic nervous system to make people wake up also increases the heart rate and blood pressure. What’s more, sleep apnea causes hormone levels to change in a way that reduces the effectiveness of insulin, leading to higher blood sugar and potentially diabetes, he says.
In children, sleep apnea can slow physical and mental growth and make it more difficult to learn. Experts don’t yet know whether kids with the condition face the same long-term health risks as adults.
In obstructive sleep apnea, the muscles in the back of the throat go limp and cause the airway to collapse, leading to labored breathing and loud snoring. When a person is overweight, fat tissue in the throat makes the airway narrower and even more prone to collapse. And since the airway reaches from the back of the nose to where the vocal cords begin in the middle of the neck, airway collapse can occur in multiple sites.
A person is diagnosed with sleep apnea if he or she has at least five apnea events per hour, accompanied by daytime sleepiness. But experts say that five events per hour is a fairly mild case. Many people suffer from moderate (15 to 30 apneas per hour) or severe (more than 30 per hour) forms of the condition.
“They might be waking up hundreds of times during the night,” Ancoli-Israel says.
Some people have mild enough symptoms that the condition can be alleviated with minor changes, such as sleeping on one’s side rather than on the back.
But for those with more stubborn cases, the most common treatment is continuous positive airway pressure, or CPAP. There are many versions, though they all include a mask hooked up to a machine that blows air into the airway, acting like a virtual splint to help keep it open. Some masks cover the nose and mouth, while others cover the nose only or use tubes to blow air directly into the nostrils.
When used properly, CPAP is extremely effective. A study last month in the journal Sleep found that after three weeks of CPAP treatment, patients with severe symptoms saw marked improvements in daytime sleepiness and fatigue.
But not everyone wants to wear a mask to bed. “It’s not very pretty, it’s not very sexy and it can be uncomfortable at first,” Ancoli-Israel says.
One new alternative is Provent, a much smaller device that emulates CPAP but uses the pressure created by a person’s own breathing to maintain airflow. It consists of two circular stickers, each with a miniature valve in the middle. They cover the nostrils during the night -- similar to a pair of Band-Aids -- and are thrown away in the morning. A forthcoming study from the journal Sleep found that patients who used Provent consistently had significantly fewer apnea events and less daytime sleepiness.
Dental mouthpieces are another option for treating mild to moderate sleep apnea, especially for patients who are only modestly overweight. The devices are similar to retainers -- they push the lower jaw forward, bringing the tongue forward as well and widening the airway as a result, Epstein says.
The mouthpieces are becoming more sophisticated, but doctors don’t yet have enough experience with them to know how well they compare with CPAP over the long term, says Dr. Phyllis Zee, an expert in sleep disorders at Northwestern University’s Feinberg School of Medicine in Chicago.
The drawback with all of these approaches is that they must be used indefinitely -- none of them offers a cure. So sleep experts sometimes look to other solutions to keep the airway open.
Weight loss is usually prescribed, which can improve or even resolve the condition. But people who are not getting restful sleep have a difficult time finding the energy to exercise and stick to a weight-loss diet.
In some cases, doctors recommend surgery to remove excess tissue from the airway -- such as the tonsils and soft palate at the back of the roof of the mouth -- to help prevent its collapse. But surgery works for only 40% to 50% of patients, and the success of these operations is difficult to predict.
Reconstructive jaw surgeries can also be used to enlarge the airspace, but they require multiple procedures to break the lower jaw in order to move it forward, Kryger says. Only a few medical centers perform the operation.
Sleep experts are also looking to new technologies, which they say hold promise but are not yet proven.
One involves an implant that is similar to a pacemaker. It emits an electrical signal to stimulate the nerves leading to the tongue while a patient sleeps to keep the tongue muscle more taught, effectively moving it forward and opening the airway. Another wire snakes down between the ribs to synchronize the electrical stimulation with the patient’s breathing. Several companies are carrying out clinical trials to determine the safety and effectiveness of the technology.
Sleep specialists are also doing preliminary research on a technique called neuromodulation, which uses a device to emit a tone into a patient’s ears during sleep. This is supposed to stimulate parts of the brain that control the tongue and upper airways, keeping them taut. The technology is still years away from use, Kryger says.
Though there is no perfect solution for sleep apnea, experts stress the importance of sound sleep. “This is a very serious disorder,” Ancoli-Israel says. “There are consequences to not getting oxygen to your brain at night.”
--
--
(BEGIN TEXT OF INFOBOX)
--
Know the symptoms
Many people with sleep apnea are not aware that they have it. Because the disorder is so prevalent, sleep experts say that doctors should routinely ask patients about the quality of their sleep.
If you suspect that you or someone you know might have sleep apnea, it is important to seek medical advice. Symptoms include loud snoring, gasping and pauses in breathing while you sleep; high blood pressure; daytime sleepiness; and cognitive impairment.
Diagnosis usually requires an overnight sleep evaluation. Experts recommend that if your child snores, is very sleepy during the day and has behavioral symptoms such as hyperactivity, irritability or concentration problems, discuss it with a pediatrician.
“Getting a good night’s sleep is not just about feeling good,” says Dr. Lawrence Epstein, chief medical officer at Sleep HealthCenters, a network of clinics based in Brighton, Mass. “It’s good for overall health.”
--
Amanda Leigh Mascarelli
--
Organizations that can help
For more information about sleep apnea, try these organizations:
American Sleep Apnea Assn., www.sleepapnea.org
National Sleep Foundation, www.sleepfoundation.org
American Academy of Sleep Medicine, www.aasmnet.org
