Sleep Apnea

Sleep Apnea

Human Physiology - Biology 60

The dictionary defines sleep as "The natural periodic suspension of consciousness during which the powers of the body are restored" (Webster's 638) If one is waking up on an average of 300 times per night, the chances of complete body restoration are minimal. The Greek word apnea literally means "without breath". An estimated 30 million Americans stop breathing during their sleep sometimes 30-40 times per hour and often for a minute, or longer each time. Of these, about 20 million are in the early stages, and about 10 million have progressed to a level of severity that requires treatment. According to the National Commission on Sleep Disorders Research, about 38,000 Americans die of sleep disorder related problems each year (Internal Medicine Alert 98). Obstructive Sleep Apnea (OSA) is a potentially deadly sleep disorder, where by the uvula and soft pallet collapse on the back wall of the upper airway causing the cessation of breathing and a drop in blood pressure. The hearts need for oxygen increases during apneic episodes, when someone stops breathing carbon dioxide slowly builds up in the bloodstream and the oxygen level quickly decreases (Melville 52). Eventually a signal from the brain triggers the body to partially wake up, this action causes blood pressure to increase, breathing, then resumes, and the cycle begins again. (See figure 1)1 Once the breathing resumes the oxygen level then begins to rise, the heart starts pumping much faster than normal, raising the blood pressure to dangerously high levels. These occurrences night after night increase the risk of damaging small organs and can trigger small strokes.

Figure 1

There are three types of apnea: Obstructive Sleep Apnea (OSA), the most common, caused when the soft tissue in the rear of the throat collapses and closes. The second type is Central Sleep Apnea; instead of the airway collapsing the brain fails to signal the muscles to breath. The third type is Mixed Apnea and as the name suggests it is a combination of OSA and Central Apnea. This paper will focus on OSA, the history, risks, diagnosis, and treatment.

OSA is a vastly undiagnosed and untreated disorder and is becoming one of America's most serious general health issues. As more research is conducted the standard risk factors being used by practitioners to diagnose and treat OSA are becoming obsolete. The factors used for diagnosing OSA were limited to overweight males in there 40's; it is now known that OSA affects men and women of any age and children. The first sleep disorder was identified in 1956. The disorder was named "Pickwickian Syndrome" patients that suffered from this syndrome were all overweight and experiencing daytime sleepiness. The name Pickwickian comes from a Charles Dickens play "Pickwick Papers" one of the characters-Joe the fat boy-was so sleepy he fell asleep standing up (Dement 175). OSA was not discovered in the United States until 1970 when Dr. William C. Dement was asked by a colleague at the Stanford University Medical School to do sleep recordings on a group of Pickwickian Syndrome patients. The results of the all-night sleep study concluded that there was a significant amount of disruptive breathing through out the night. In 1965 a group of European researchers did a similar sleep study. At that time all of the studies of Pickwickian Syndrome were conducted on subjects during the daytime while the patients were awake and experiencing their daytime sleepiness. The European sleep study had found that patients stopped breathing for several seconds, many times a night, Dr. Dements had reached the same conclusions after his study showing that some patients stopped breathing for as long as 90 seconds per apneic episode this was a potentially deadly disorder. Unfortunately the Europeans discovery of this condition went unnoticed, as there was very little interest at that time in the medical community concerned with sleep.

In 1970 Dr. Dement founded the world's first sleep disorders center at Stanford University introducing all-night polysomnographic examination of patients with sleep related complaints. He and partner Christian Guilleminault then started conducting the all-night tests on patients visiting the clinic thought to either have Picwickian Syndrome or Narcolepsy, a condition that was also diagnosed early on for daytime sleepiness. The results of his initial testing found that 90% of the patients tested with the all-night polysomnographic examination had OSA. In 1975 Dr. Dement launched the American Sleep Disorders Association and developed the Multiple Sleep Latency Test which remains the standard diagnostic measure of daytime sleepiness. It was at this time that Dr. Dement and partner Christian Guilleminault decided to rename Pickwickian Syndrome, Sleep Apnea. At the time it was believed by practitioners that only obese people could have OSA. With continued testing and research it is now known that anyone could have OSA regardless of size, age or gender. Obesity does however remain one of the principal concerns.

The health risks can become deadly over time, most people with OSA do not seek medical attention until a partner complains about loud snoring or they are experiencing irregular breaths. Symptoms include obesity, a large neck, snoring, choking in sleep, hypertension, memory loss, weight gain, impotency, excessive daytime sleepiness, and headaches. In addition OSA is associated with cardiovascular diseases, stroke, renal problems and glaucoma (Alonso-Fernandez 18). Some people have facial deformities or may have a jaw smaller than average or have a smaller opening at the rear of the throat, nasal polyps, and enlarged tonsils. These factors can also contribute to a blocked airway during sleep. Continuing research is showing that OSA is also a contributing factor to other diseases.

Dr. Naresh M. Punjabi of the Johns Hopkins Medical Institute led a large study that links apnea to two conditions - glucose intolerance and impaired insulin function, that are associated with the onset of type 2 diabetes. "We think the sleep problems are more likely contributing to glucose intolerance and diabetes instead of those conditions explaining the apnea," says co-author Rachel Givelber of the University of Pittsburg (Parsell 195-196). The findings which appear in the September 15, 2004 American Journal of Epidemiology, could have important implications for identifying and managing diabetes. "Based on this study" says Givelber "if