“Now I lay me down to sleep,
I pray the Lord my soul to keep,
If I shall die before I wake,
I pray the Lord my soul to take.”  – Children’s prayer

Sleep apnea is a very chronic, serious and potentially dangerous sleep disorder in which the person experiences abnormal temporary halts in breathing.  Each of these breathing pauses, known as “apnea”, can last anywhere from a few seconds to minutes, and in severe cases can happen up to 30 times or more an hour.  When breathing resumes it often does so with a rather loud and abrupt choking or snorting sound.  During these periods of apnea the individual goes from a period of deep sleep into light sleep.  As a result, most sufferers feel tired throughout the day even after reporting having had a full night’s sleep.  Snoring is also common amongst individuals with sleep apnea.  Unlike most other conditions, sufferers of sleep apnea are rarely aware that they are having any sort of difficulty breathing during their sleep, or for that matter even when they awaken.  Sleep apnea is actually most often identified by a family member or bed partner observing the person struggling with their breathing during sleep, and can occur in children as well as adults.  The symptoms of sleep apnea can go on literally for decades, as there are no blood tests to check for the condition, and it is something not usually detected during a routine physical exam.  Over time the sufferer becomes accommodated to the daytime fatigue and other associated symptoms leading even further away from raising a medical “red flag”.  In the first part of this two-part series the reader will be presented with: an overview of sleep apnea; a description of the three main types; common signs and symptoms; and, causes and risk factors.

There are three main types of sleep apnea:

• Obstructive sleep apnea (OSA) – by far the most common form, representing approximately 85% of reported cases, results from an actual physical blockage of airflow most often due to the excessive relaxation of throat muscles.  The airway walls in the throat are made up of soft tissue which is collapsible and can actually obstruct breathing during the sleep process.  Although the likelihood of OSA increases with weight and age, and is more common in men than in women, it can occur in anyone.  Diabetics actually have an almost three-time greater risk of developing OSA. The more common symptoms of OSA are:  loud snoring; restless/agitated sleep; and, a lot of daytime sleepiness.
• Central sleep apnea –  also known as Cheyne-Stokes respiration, is by far the rarest form, representing less than 1% of diagnosed cases of sleep apnea, occurs when the brain’s respiratory (breathing) control centers become out of balance during sleep.  In individuals with normal sleep breathing is regular, and as a result oxygen and carbon dioxide levels in the bloodstream remain fairly constant.  In central sleep apnea the basic neurological controls for breathing malfunction and fail to give the signal to inhale, causing the individual to miss one or more cycles of breathing.  This can lead to a significant, and potentially dangerous, drop in oxygen and rise in carbon dioxide in the blood.  Chronic large dose opiate narcotic use can lead to respiratory depression and during sleep present as central sleep apnea.  Snoring does not typically occur in this type of sleep apnea.
• Mixed or Complex sleep apnea – representing approximately 15% of cases, is a combination of both obstructive and central sleep apnea.  When OSA is extreme and persistent episodes of central sleep apnea can develop.

The most common signs and symptoms of sleep apnea include:

• Loud and chronic snoring (although pauses in snoring may occur).  The snoring is usually the loudest when sleeping on your back, and may be less loud when sleeping on your side.  Over time the snoring will typically get louder and more chronic.  Of course, not everyone who snores has sleep apnea.
• Intermittent choking or grasping for breath while asleep.  The choking and grasping happens while you are asleep, and as such you will likely be totally unaware it is even occurring.  It is likely that a bed partner or family member will notice the problem before you do.
• Awakening frequently to urinate
• Excessive night time sweating
• Morning headaches
• Dry mouth and/or sore throat upon awakening
• Increased irritability
• Depression and/or mood swings
• Memory and or learning problems
• Poor concentration
• Battling sleepiness throughout the day
• In children:  poor school performance; angry behavior; and, hyperactivity.

Obstructive sleep apnea occurs as a result of severe narrowing of the breathing passageway preventing air from flowing freely into and out of the lungs.  The throat muscles are what helps keep the airway firm and open so that air can move in an unrestricted manner.  When you sleep, it is these muscles that relax which can lead to a narrowing of the airway.  The airway can become constricted, or completely blocked, as a result of:

• The shape of the bony structure of your head and neck may create a diminished size in the airway of the mouth and throat area.
• In those who are severely overweight additional soft fat tissue and thicken the area around, and thereby narrow, the trachea (“windpipe”).
• The tongue and throat muscles are overly relaxed.
• Overly enlarged tonsils and adenoids
• As we get older the signal from our brain to the throat muscles to maintain good muscle tone diminish leading to a narrowing of the airway.

A lack of adequate airflow to the lungs during sleep can not only cause loud snoring and fatigue, but can also lead to a significant drop in blood oxygen level.  When the blood oxygen concentration drops to an unsafe level it triggers the brain to disrupt sleep in order to re-establish muscle tone in the throat area and open up the windpipe.  It is this re-start of normal breathing and airflow that creates the loud snorting or grunting sound very often seen in this condition.  These recurring significant drops in blood oxygen level, and the resulting persistent disruption in sleep quality will oftentimes cause the release of stress hormones.  These hormones not only increase heart rate, but further increase the risk of hypertension (high blood pressure), stroke, heart attack, and heart failure.  Sleep apnea left untreated can also increase risk of diabetes, obesity and sleep-deprived driving accidents.  A few years ago researchers further demonstrated that people with obstructive sleep apnea oftentimes show tissue loss in the area of the brain that aids in memory, thereby showing a link between OSA and memory loss.  It is thought that the repeated drops in oxygen levels lead to this brain tissue injury.

Those afflicted by sleep apnea often complain of impaired attentiveness, diminished reaction time, and excessive daytime fatigue.  As a result of the associated disturbance in daytime cognitive functioning behavioral changes are also often observed.  These can include periods of hostility, moodiness, and a decrease in motivation, determination and concentration.  Because many of these effects can be caused by a variety of other factors it is not uncommon that sufferers of sleep apnea have no idea they are suffering from this disorder, are easily misdiagnosed, or often will just disregard the symptoms altogether.

Next Saturday, in Part 2 of this two-part series, I will discuss how sleep apnea is diagnosed and the various treatment options available.