Adult Sleep Apnea: Breathless No More

by Food and Drug Administration (FDA)

Imagine ceasing to breathe for 10 to 20 seconds, then strenuously gasping in air, then stopping again — hundreds of times during what is supposed to be eight hours of restful slumber. For the sleep apnea sufferer, this happens every night.

Fortunately, the relentless lapses in breathing are not remembered, even though up to three-quarters of total sleep time may be spent not breathing!

Apnea is Greek for "want of breath," and the condition causes problems in both infants (see "Infant Apnea Monitors Help Parents Breathe Easy" in the June 1991 FDA Consumer) and adults.

For adults, sleep apnea may actually be more disturbing for the bed-mate than for the affected individual, for the frequent fits and starts of breathing are often accompanied by snoring reminiscent of a jackhammer.

Fortunately, a variety of highly effective treatments for sleep apnea are available. They range from simple solutions, such as taking a decongestant or avoiding sleeping on one's back, to surgery. Many sleep apnea sufferers find relief with a mask-like device, cleared for marketing by the Food and Drug Administration, that painlessly forces air into respiratory passages that become blocked during sleep.

Untreated, apnea can greatly affect daytime functioning. Rarely, the only daytime hint of the nocturnal turmoil may be a sense of having slept poorly. But far more often, the person is aware in many ways that all is not right. Awakening is often accompanied by a fierce headache, which lessens in an hour or two. But the person may remain irritable and forgetful, often finding it difficult to concentrate for the rest of the day. Interest in sex may wane, and the person may become depressed.

Annoying as these symptoms are, they aren't the most dangerous. Of far greater concern is the tendency of sleep apnea sufferers to fall asleep, suddenly, during the day. Dozing can prove embarrassing in business meetings or classes, but in some situations, it can be deadly.

Martin Scharf, Ph.D., director of the Center for Research in Sleep Disorders in Cincinnati, says, "There are 200,000 auto accidents a year where people fall asleep at the wheel. I see people every day who say they fall asleep whenever they are at a stop sign."

It's not surprising that people with sleep apnea face a two- to fivefold greater risk of being in an auto accident compared with people who do not have sleep apnea. The American Sleep Disorders Association calls the condition "a potentially life-threatening disorder."

Portrait of a Sleep Apnea Sufferer

Snoring is not always a sign of sleep apnea. One in 10 adults snores, but only 1 in 10 snorers has sleep apnea. This accounts for some 6 million people, with men outnumbering women 8 to 1. Researchers are not certain why the typical sleep apnea patient is a middle-aged overweight man, but they think it may have something to do with hormones and neck size.

Scharf explains the neck connection. "In young men, the neck is more muscular. When they get older, out of shape, the muscle shrinks and fatty deposits come in. Muscle is heavy. When it loses its tone, the airway collapses." Neck size is largely inherited — and a hefty neck isn't seen only in overweight people.

In one study, researchers at the Osler Chest Unit of Churchill Hospital in Oxford, England, queried 900 male patients between the ages of 35 and 65. Did they smoke? Drink alcohol? Take drugs? Have a stuffy nose? Measurements taken included weight, height, neck circumference, and resting arterial oxygen saturation, a measure of how much oxygen is getting into the bloodstream. The only two factors that correlated with apnea were alcohol intake (which greatly worsens symptoms) and neck size! Weight was implicated in a study of more than 1,000 sleep apnea patients at the Stanford Sleep Disorder Clinic. Two-thirds of the patients were obese — defined as being 20 percent or more above ideal body weight.

Premenopausal women are more protected than older women. With menopause, the prevalence of sleep apnea among women becomes closer to that for males. But which hormone, and how it affects breathing, isn't known, says John Shepard, M.D., director of the Sleep Disorders Clinic of the Mayo Clinic in Rochester, Minn.

Role in Other Disorders

Experts believe that sleep apnea probably has several causes. Some cases are part of an underlying hormonal disorder, such as hypothyroidism (an underactive thyroid gland) or acromegaly (excess bone growth due to oversecretion of growth hormone). Sleep apnea also occurs in some patients with Marfan syndrome, an inherited disorder in which anatomical structures built of connective tissue are very weak. A Marfan patient's weakened airway may collapse easily, impeding airflow.

The repeated stop-and-go oxygen delivery in apnea stresses the heart and blood vessels. Sufferers are "two to three times as likely to have hypertension, and have triple the risk of having a stroke, due to oxygen levels dropping," says Scharf. The older and more overweight the patient, the greater the risk of a cardiovascular complication. Hypertension that arises during the night may persist during the day, even though breathing while awake is normal.

Richard Millman, M.D., and co-workers at Rhode Island Hospital in Providence compared prevalence of hypertension among 152 men with sleep apnea and 904 men of similar ethnic background and geographic location who did not have sleep apnea. When the researchers looked at age and weight, they found that the prevalence of hypertension differed in the two groups only among obese men aged 25 to 44. Hypertension, they conclude, may develop only in this subset of apnea sufferers. Women were not evaluated in the study.

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.