Who Is Most at Risk for Sleep Apnea?

Both my father and my uncle suffer sleep apnea. I, myself, haven’t noticed any symptoms, but my wife says I snore loudly. I know this can a sign of sleep apnea, but I wonder if it’s just plain old snoring? What are the risk factors for sleep apnea?

The risk factors for sleep apnea depend on the type of sleep apnea we’re talking about. There are many different contributing factors to two different types of sleep apnea: Central and obstructive.

Central Sleep Apnea Risk Factors

Central sleep apnea syndromes may be divided into two groups; primary (without an underlying cause) or secondary (as a consequence of another condition). In general, central sleep apnea stems from an abnormal regulatory mechanism in the brain.

Some common causes of central sleep apnea include:

• strokes,
• heart failure,
• certain medications,
• some congenital abnormalities, or
• high altitude.

In central sleep apnea, the brain’s regulatory mechanism that monitors levels of oxygen and carbon dioxide in the blood is disrupted and the brain's recognition of, or response to, oxygen and carbon dioxide levels is impaired.

As breathing stops or slows down, the oxygen level drops significantly lower and the carbon dioxide level increases significantly higher than the levels necessary to trigger normal breathing. This leads to a transient exaggerated over-breathing to compensate for significantly higher levels of carbon dioxide and lower oxygen levels. Subsequently, the over-breathing can result in overshooting the oxygen and carbon dioxide levels, initiating another episode of apnea.

Obstructive Sleep Apnea Risk Factors

In obstructive sleep apnea, the problem is not the regulation of breathing by the brain, but rather, it has to do with an obstruction to the flow of air into the lungs. The brain signals the muscles of breathing to take a breath. The muscles attempt to take a breath, but no air can flow due to the obstruction of air flow. Therefore, the oxygen levels fall and carbon dioxide levels rise to a level that signals the brain to wake the body up to take a breath (resulting in gasping for air).

The following are risk factors for obstructive sleep apnea:

• a deviated nasal septum,
• nasal congestion,
• narrow airway passages,
• enlarged tonsils,
• weak pharyngeal muscles,
• lowered vocal tone (may be related to medications or alcohol),
• vocal cord injury,
• facial trauma leading to distorted airway passages, or
• retraction of the tongue to the back of the throat.
• obesity and weight gain (leading to narrow air passages),
• some sedative medications and alcohol (leading to lax pharyngeal muscles, soft palate, and tongue),
• neuromuscular diseases (such as stroke, leading to weak airway muscles),
• upper respiratory infections (leading to narrow and swollen nasal passages), and
• smoking.