Research studies have shown that obstructive sleep apnea (OSA) is associated with a variety of unpleasant health problems. These include high blood pressure, heart attacks, strokes, heart failure, irregular heart rhythm, diabetes, and early and sudden death. OSA is clearly associated with an increased risk of accidents, both industrial and while driving, so OSA can cause devastating consequences not only for the person with the disorder, but for innocent bystanders as well. Persons with OSA can have problems with learning and memory, as well as decision making. Mood can be altered.

We don't know exactly why all these associated problems happen. OSA has two clear consequences during at night. One is brief arousals from sleep that fragment sleep and another is episodes of low blood oxygen (desaturation or hypoxic events). The frequency of obstructive breathing events during sleep is usually expressed as the Apnea /Hypopnea Index (AHI) or the number of abnormal breathing events per hour of sleep. A clear daytime consequence of OSA is excessive sleepiness, the tendency to fall asleep when you don't intend to. One would expect that the more frequent the breathing problem during sleep, the higher the AHI or the more severe the hypoxic insult to the body, the sleepier the person with OSA would be. Generally this tends to be true, but the relationship between the severity of OSA in terms of AHI or hypoxia and daytime sleepiness is not real strong. While we tend to think of the daytime sleepiness as being due to the sleep disruption or arousal, some research suggests that hypoxia (low oxygen) also plays a role.

Hypoxia is thought to play a major role in causing high blood pressure, and high blood pressure is itself associated with heart attacks, heart failure and strokes. One very large study found that blood pressure went up directly as AHI went up. Another large ongoing study has found 18 years after the initial diagnosis, death from all causes was linked to the severity of sleep apnea as measured by the AHI.

A cofounding factor in many studies of the consequences of OSA is the fact that most people with OSA are fat. Obesity alone is linked to cardiovascular disease and may be linked to sleepiness.

Regardless of the fact that we do not understand all the links between sleep apnea and its consequences, it is clear that treating sleep apnea prevents or lessens the consequences. So if you have OSA, treat it. You will feel better and liv