Sleep apnea (patient information)

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 * Assistant Editor-In-Chief: Katherine Ogando

Overview
Snoring, the result of the vibration of respiratory structures caused by the irregular flow of air, is a previously-thought harmless condition that has recently been gaining recognition as a marker for heart disease.

Though often linked to, but not the same as snoring, sleep apnea is a condition in which the individual stops breathing for more than 10 seconds during sleep. The episode is often followed by a sudden attempt to breathe and a change to a lighter stage of sleep. These pauses can occur 20 to 30 times or more in an hour.

After insomnia, obstructive sleep apnea is the leading cause of drowsiness during the day. It affects up to 18 million Americans, yet 90% of people with this condition are unaware of having it. Research points to a correlation between sleep apnea and heart disease, with about 50 percent of coronary heart disease and high blood pressure patients also exhibiting symptoms of sleep apnea. Sleep apnea treatments, if effective, can help alleviate the effects on heart disease and improve the patient’s quality of life.

Types of sleep apnea
There are two types of sleep apnea: central sleep apnea (CSA) and obstructive sleep apnea (OSA). CSA is less common than OSA and is usually the result of damage to the brain stem resulting from an illness or injury. CSA seldom manifests itself through snoring as there is no physical obstruction of the airways.

Obstructive sleep apnea is the most common type of apnea. It is the result of the physical blockage of the airways during sleep due to the relaxation of the throat muscles. The causes for OSA are discussed in more detail in this article.

What causes Sleep apnea?
A person who has OSA is often not aware of the apnea episodes during the night. Usually, other family members notice the apnea episodes and alert the afflicted person.

A person with OSA will usually snore heavily soon after falling asleep. The snoring continues at a regular pace for a period of time, often becoming louder. It is then interrupted by a long silent period during which there is no breathing. This is followed by a loud snort and gasp, and the snoring returns. This pattern repeats frequently throughout the night.

The main symptoms of OSA are usually associated with excessive daytime sleepiness, including falling asleep at inappropriate times. Most people also report awakening unrefreshed in the morning.

Other symptoms may include:


 * Depression
 * Memory difficulties
 * Morning headaches
 * Personality changes
 * Poor concentration
 * Restless and fitful sleep
 * Frequent waking up during the night to urinate
 * Insomnia

It is not uncommon for children with OSA to display hyperactive behavior. Leg swelling has also been linked to severe OSA.

What causes Sleep apnea?
OSA is caused by the relaxation of the muscles of the back of the throat, which then impede airflow. Normally, the muscles of the upper part of the throat help keep the airway open and allow air to flow into the lungs. Even though these muscles usually relax during sleep, the upper throat should remain open wide enough to let air pass through unobstructed.

Several factors may affect the width of the throat area, and can therefore contribute to the obstruction of the airway. Having a narrower throat area can affect the ease with which air can pass through the airways. When the muscles in the narrower upper throat relax during sleep, the airway may completely close. This prevents air from getting into the lungs and loud snoring and labored breathing occur. During deep sleep, breathing can stop for a period of time (often more than 10 seconds). This is called apnea.

Who is at highest risk?

 * Gender: Sleep apnea affects adult men more often than women. According to the American Academy of Sleep Medicine, 40 percent of adult men and 24 percent of adult women are considered habitual snorers, and snoring is often associated with sleep apnea.


 * Metabolic Syndrome and Sleep Apnea:
 * Obesity: Obesity has been closely linked to OSA in part because the extra fat around the neck can narrow the opening of the windpipe. Older obese men seem to be at higher risk since up to 40 percent of morbidly obese men in a clinical population are affected by OSA . Though it is hardly the only factor that has an effect, weight loss can alleviate some of the symptoms of OSA; losing 10 percent of body weight can reduce the number of apnea episodes throughout the night.


 * Diabetes: Diabetes has also been associated with OSA independently from obesity. Studies have shown that both obese and slender people with diabetes have reported difficulty breathing while sleeping .  The causal relationship, however, has not yet been established.


 * Hypertension: There is a definite link between hypertension and OSA. One out of every 2 people who have OSA are diagnosed with high blood pressure .  The relationship between hypertension and OSA is also independent from other risk factors, including obesity.


 * Other risk factors: The following factors may also increase your risk for obstructive sleep apnea:
 * Certain shapes of the palate and jaw
 * Large tonsils and adenoids in children
 * Large neck or collar size
 * Large tongue
 * Narrow airway
 * Nasal obstruction


 * In addition to these risk factors, drinking alcohol or using sedatives before sleep may exacerbate the condition and increase the likelihood of an episode of apnea.


 * Having a neck size over 17 inches for men and 16 inches for women is also a risk factor for sleep apnea. Moreover, having a deviated septum would cause a nasal obstruction that could lead to sleep apnea.

Heart disease and sleep apnea
Sleep apnea has been linked to heart failure, chest pain, and stroke, in addition to high blood pressure. The cardiovascular complications resulting from sleep apnea are, in part, consistent with the sleep deprivation aspect of OSA.

With the exception of REM sleep, the sleep cycle provides the heart with a period of rest, where the blood pressure and heart rate slow down. Because a person with OSA stops breathing, however, the levels of carbon dioxide in the system rise to levels that trigger a response for the person to wake up. This response also causes the heart rate and the blood pressure to rise. As this occurs multiple times throughout the night, the added stress to the heart and blood vessels begins to manifest itself as different types of heart disease over time.

Arrhythmia
Cardiac arrhythmias are one of the common conditions that afflict persons with OSA, though the mechanism and the extent to which it affects the population remains unknown. Observational studies have shown that successful treatment of OSA with continuous positive airway pressure (CPAP) therapy do alleviate arrhythmias, though more research is needed to confirm these findings.

Heart failure
Heart failure has a strong link to sleep apnea. It is estimated that in patients with systolic heart failure, at least 45 percent of patients have at least 10 episodes of shallow breathing or very low respiratory rate (hypopnea) per hour. In a small study of diastolic heart failure, this number rose to 50 percent of 10 episodes per hour. A causal relationship has not yet been established, but OSA will further adversely affect a preexisting condition of heart failure.

Treatment options

 * The treatment options for OSA are varied and range from lifestyle changes to surgery. The end goal of the treatments is to keep the airway open so that breathing does not stop during sleep.

The following lifestyle changes may relieve symptoms of sleep apnea in some individuals:
 * Lifestyle changes:
 * Avoiding alcohol or sedatives at bedtime
 * Avoiding sleeping on the back
 * Losing weight

There are other over-the-counter options that may relieve mild sleep apnea coupled with snoring. These include mouthpieces and nose strips. Dental appliances may also be helpful for OSA caused by anatomical obstructions. People get these dental appliances professionally fitted by a dentist or orthodontist and they work by changing the position of the lower jaw and the tongue keep the airway open.
 * Mouthpieces:

Continuous Positive Airway Pressure, or CPAP, is now regarded as the first-line treatment for obstructive sleep apnea in most people. The CPAP treatment is a device in which air blows into a face mask, forcing air into the nose and the mouth. This keeps the airways from collapsing while the person is sleeping.
 * Continuous Positive Airway Pressure:

Many patients cannot tolerate CPAP therapy. Good follow-up and support from a sleep center can often help overcome any problems in using CPAP.

Surgery may be an option in some cases. This may involve:
 * Surgery:
 * Uvulopalatopharyngoplasty (UPPP): A medical procedure that removes excess tissue at the back of the throat.  Thirty to sixty percent of cases where UPPP was performed have resulted in improved symptoms.
 * Corrective surgery: Surgery on the nose and sinuses to correct anatomical structures such as a deviated septum.
 * Laser-Assisted Uvulopalatoplasty (LAUP): An out-patient procedure in which a laser is used to remove parts or all of the uvula at the rear of the mouth
 * Somnoplasty: A medical treatment that uses radio frequency energy to shrink the tissues that are causing OSA.
 * Tracheostomy: A surgical procedure where an opening is created in the windpipe to bypass the blocked airway if there are anatomical problems.  This surgery is only performed in cases of severe apnea in life or death situations.


 * Surgery to remove the tonsils and adenoids may cure the condition in children; it does not seem to help most adults.

Where to find medical care for Sleep apnea?
Directions to Hospitals Treating Sleep apnea

What to expect (Outlook/Prognosis)?
With the right treatment and follow-up care, the symptoms of sleep apnea should be totally corrected.

Prevention
Children with very large tonsils and adenoids may develop sleep apnea and related problems. They should be checked by a health care provider to determine whether they need further evaluation.