Sleep Soundly Every Night, Feel Fantastic Every Day (21 page)

Sleep apnea is a serious problem. Current estimates show that 18 million Americans have sleep apnea. This number has doubled since the early 1990s and survey results attribute the increase to the rising incidence of obesity in the United States. Sadly, 80% of these people are undiagnosed and untreated.

It is important to diagnose and treat this disorder. The health risks of untreated sleep apnea are substantial. A recent study showed that if untreated, people with severe sleep apnea were 25% more likely to die over a 10-year period than those who did not have the disease.

However, this sleep disorder is treatable, with good results. It's been reported that treating sleep apnea resulted in a 52% drop in motor vehicle accidents, a 49% decrease in heart attacks, and a 31% decrease in stroke in those with moderate to severe disease over a 10-year period. How I wish the train engineer and conductor, the pilots, and the truck driver had received treatment!

Obstructive Sleep Apnea is a common disorder affecting at least 2% to 4% of the adult population. The closing or obstruction of the airway is the defining trait of OSA. Most people experience pauses in breathing while they sleep. For people with sleep apnea, these pauses occur more often, and sometimes as often as once or twice each minute. Other symptoms of apnea include the telltale snoring, shallow breathing, as well as a choking or snorting sound whenever the person awakens (because they are not breathing!) The symptoms and subsequent consequences of OSA are the result of the repetitive collapse of the upper airway that obstructs breathing.

The upper airway is not a rigid structure. Its ability to stay open depends upon a balance of forces. Normal muscle activity that contributes to keeping the airway open relaxes when we go to sleep. If the airway is smaller to begin with because of fat deposits, anatomy, or more frequently in the case of children, enlarged tonsils and adenoids, the airway is more likely to collapse while you sleep.

The other contributing factor is the force exerted to inhale at night. The more forceful the effort, the more negative the pressure in the upper airway. This contributes to collapse, especially during sleep when the opposing dilator muscles are not at full strength. That is why sleep apnea may worsen with nasal congestion and is more likely in mouth breathers.

Finally, alcohol and many of the commonly prescribed sleep aids can weaken the upper airway muscles during sleep. This further promotes the collapse and sleep apnea.

  
When you fall asleep, the upper airway muscles relax. You lose the ability to control their strength.

  
If you have an airway with a smaller diameter, then you are more likely to experience collapse and obstructed breathing when you fall asleep.

  
Factors such as obesity, large tonsils, or a backward positioned jaw can result in a smaller airway.

  
In addition, alcohol and certain medications can further weaken the muscles when you are asleep.

Phil's cardiologist sent him to me. Phil had an irregular heartbeat, called atrial fibrillation, that he most frequently noticed upon waking in the morning. Phil is 59 years old, relatively healthy with no underlying medical problems, but he keeps going into atrial fibrillation. He had already been to the emergency room and admitted on two occasions. The attending physician used cardioversion to reset his heart rhythm electrically, back to its regular pattern.

For some reason, Phil kept going back into atrial fib. Finally, his cardiologist asked him, “Well, do you snore?”

“My wife says my snoring is not loud, so it isn't a big deal.”

“Phil, it could be a big deal because we now know that a very common cause of atrial fibrillation is sleep apnea. On top of that, we also know that after cardioversion, if we don't treat the sleep apnea, up to 50% of patients will go back into the atrial fibrillation.”

When Phil arrived in my office, I observed a beefy, overweight, middle-aged man. He was a little skeptical, asking, “Well, how come I'm not sleepy? How come I don't feel tired?”

“You know, Phil, we don't know yet that you have sleep apnea, but I certainly suspect it, based upon your history of morning awakenings with atrial fib and your snoring. What you might find interesting is that several studies show that cardiac patients with sleep apnea tend not to present with sleepiness. That means that the sympathetic nervous system is on overdrive, which may be part of the problems with cardiac patients to begin with. Therefore, your alerting system is in overdrive all day long, so you tend not to get sleepy. Frequently, the first inkling we have of sleep apnea is when you go into atrial fibrillation or you have your first heart attack.”

Phil listened, nodded, and was willing to seriously consider the recommendation put to him by his cardiologist and me. He went to the sleep study, and found he had sleep apnea. Actually he has a significant sleep apnea, which means he stops breathing 30 to 40 times an hour.

Believe it or not, during one of those episodes, he had a short run of atrial fibrillation, which went away. I've seen that happen before. When Phil returned to see me, I was able to show him on the computer, “Here you are. You stopped breathing. We even have you going into a short burst of atrial fibrillation at the end of one of your apneas.”

He stared and shook his head, not in denial, but more like, wow!

“Phil, I said, “you are lucky your cardiologist referred you to me. Most cardiac patients don't seek out any help because they're not sleepy. Unfortunately, the first time I see them is when they have an event.”

“I am lucky, Doc. I appreciate knowing. Now I can get some help.”

The autonomic nervous system consists of the “fight or flight” sympathetic nervous system and the parasympathetic nervous system. Normally, when we go to sleep, the calming parasympathetic nervous system predominates and our blood pressure drops an average of 10 points. However, in people with sleep apnea, there is a stimulation of the sympathetic nervous system during sleep. This is in response to the low oxygen levels that accompany the respiratory events in conjunction with the stress response brought on by the effort to breathe against a closed airway. This results in surges of blood pressure as high as 240 mmHg at the termination of each of these events. Therefore, people with sleep apnea lose the normal drop in blood pressure with sleep. In fact, their blood pressure may skyrocket. Eventually, this nocturnal elevation spills over into the daytime and results in persistent hypertension. This, as well as other factors we will go into in the following questions and answers, results in end organ damage to the heart and brain. In part, because of this, recent studies have shown the incidence of sleep apnea in heart attack and stroke victims to be over 50%.

In addition to the other health risks, sleep apnea can also wreak havoc with your brain. Using a combination magnetic resonance imaging (MRI) and voxel-based morphometry (VBM), researchers have determined that patients with untreated sleep apnea have decreased gray matter over several regions of the brain. These areas, including the hippocampus and frontal lobes, control several executive functions, including skills in planning, working memory, attention span, problem solving, verbal reasoning, and multitasking. Perhaps this is why people with sleep apnea are sometimes misdiagnosed with early onset Alzheimer's.

Sleep apnea has also been associated with emotional disorders, including anxiety, PTSD, obsessive-compulsive disorder, and panic disorders. The research in this area began when physicians began noticing a high rate of coexistence between these disorders and sleep apnea. Given the statistics, they knew it had to be more than a coincidence; however, it was years before they could figure out the connection.

Recent studies indicate that sleep apnea is the cause of these disorders, not the other way around. In addition to gray matter, apnea also affects the brain's limbic system. One of the functions of the limbic system is to regulate the endocrine system, including stress hormones. An increase of these hormones can trigger the sympathetic nervous system, higher levels of anxiety, and even the “fight or flight” response to external stimuli. In addition, sleep apnea also interrupts the stages of sleep, particularly REM (rapid eye movement). The REM stage is the time when one processes the stressful events they experienced during the day; therefore, when REM is continually interrupted, the patient misses out on the opportunity to purge him- or herself of trauma. This also increases stress hormones, and after an extended period, creates the secondary emotional disorder.

A study presented at the 2013 American Thoracic Society International Conference demonstrated that in people with prediabetes, treatment of associated sleep apnea improved blood sugar control. Two weeks of treatment with continuous positive airway pressure (CPAP) resulted in a significant lowering of blood sugar.

We have known for several years that there is a link between diabetes and sleep apnea. Sleep apnea is a
stress-producing condition occurring while a person is asleep. It results in high levels of cortisol and activation of the sympathetic nervous system. This can result in significant elevations in blood sugar. At the same time, it is also ruining your oxygen levels. This causes the release of substances called inflammatory mediators, which inhibit the ability of insulin to get into the cells. This is referred to as insulin resistance. In response, the pancreas, where insulin is produced, attempts to put out more and more insulin. However, there comes a time when it can no longer do this, and that is when prediabetes becomes diabetes.

We know that the incidence of sleep apnea in diabetics is high. Previously it was felt that obesity, which is common to both conditions, was the link. However, now it is becoming increasingly clear that sleep apnea may be the cause of diabetes in those who suffer from this breathing disorder.