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Mike, a 37-year-old male, considered himself healthy. He exercised moderately two or three times a week, but since he worked for a large financial corporation he spent long hours at his desk and frequently dined with customers. As a result of his sedentary lifestyle and rich diet, his BMI was 28.6^*. He presented at his doctor's office complaining of lethargy and sleepiness during the day. In addition, he often had headaches in the morning and his wife mentioned that he had begun to snore loudly.

The physician ordered a polysomnogram, or PSG, to record Mike's brain activity, eye movement, muscle activity, breathing and heart rates, lung function and the percentage of oxygen in his blood throughout the night. After studying the test results, the physician diagnosed Mike with obstructive sleep apnea, the most common type of sleep apnea. The number of people in the west suffering from obstructive sleep apnea has increased in line with increased levels of obesity, as well as improved awareness and diagnosis¹.

Sleep apnea occurs when a person regularly stops breathing for ten seconds or longer during sleep. It ranges from mild to severe, depending on the number of times in an hour that apnea (breathing stops) and/or hypopnea (breathing becomes very slow) occur. Obstructive sleep apnea is caused by a blockage or narrowing of the airways in the nose, mouth or throat. Factors that cause sleep apnea include: obesity, large tonsils and adenoids, throat muscles and tongue that relax more than normal, and a bony structure of the head and neck that result in a somewhat smaller airway size in the mouth and throat area².

Sleep apnea disrupts sleep and reduces its quality. It may result in many brief drops in the blood's oxygen levels and interrupts "sleep architecture" or sequence of stages. Healthy sleep normally begins with about eighty minutes of non-rapid eye movement, or NREM, when brain activity and bodily functions slow down. Each NREM stage is followed by about ten minutes of rapid eye movement, or REM, during which brain and body activity increase. REM is the stage during which dreams occur. This ninety-minute cycle is repeated four to six times each night³. A good night's sleep (seven to eight hours) enables people to function both mentally and physically. During sleep, the body secretes growth hormone, which promotes the repair and regeneration of tissues throughout the body⁴.

There are a variety of treatments for obstructive sleep apnea, and treatment often helps associated medical problems such as high blood pressure, as well as reduces the risk for heart attack and stroke⁵. Mild cases of obstructive sleep apnea can be treated with lifestyle changes, such as: losing weight; avoiding alcohol, smoking and medicines that cause drowsiness; and by sleeping on one's side. Moderate cases are usually treated with continuous positive airway pressure (CPAP), in which a mask blows air into the throat at a pressure level that keeps the throat open during sleep. Surgery to remove the tonsils and adenoids, or surgery to treat obesity is performed in serious cases. In Mike's case, CPAP proved to be an effective treatment.

* Underweight =<18.5, Normal weight = 18.5-24.9, Overweight = 25-29.9, Obesity = BMI of 30 or greater

Discussion questions

1. Please summarize the article. What is the main point of the article?
2. Describe Mike's symptoms and the physician's diagnosis.
3. What is obstructive sleep apnea?
4. What causes obstructive sleep apnea?
5. Why is the incidence of sleep apnea increasing?
6. What is "sleep architecture"?
7. Why is it important to sleep seven to eight hours every night?
8. How can sleep apnea be treated?

References:

1. http://www.ft.com/cms/s/ed7f38f8-f200-11db-b5b6-000b5df10621.html. (Accessed 25 April 2007)
2. Sleep apnea. U.S. Department of Health and Human Services, National Institutes of Health, National Heart Lung and Blood Institute. (Accessed 25 April, 2007)
3. Healthy sleep. Shuteye.com. Sanofi-Aventis. (Accessed 25 April 2007)
4. Healthy sleep. Shuteye.com. Sanofi-Aventis. (Accessed 25 April 2007)
5. Sleep apnea. U.S. Department of Health and Human Services, National Institutes of Health, National Heart Lung and Blood Institute. (Accessed 25 April, 2007)

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