There are 5 stages to the sleep cycle.  Some group stage 2 and stage 3 together and say there are 4 stages to the sleep cycle.  But the last two stages are always the same, no matter who you listen to.  I like to use the 5 stage cycle.

The last stage is always called rapid eye movement of REM.  That’s because your eyes are moving rapidly every which way in this stage.  And you should be moving through the 5 stages 4 to 5 times each night and spending a total accumulated time in REM of 120 minutes.  It’s in this stage of sleep that you always dream, so you have the potential of having 4 to 5 dreams each night.  I know I do. 

Researchers studies over 300 participants who were over 60 years of age for 12 years.  They used data from the Framingham Heart Study.  The results showed that for each percentage of REM sleep reduction, there was a 9% increase in dementia risk and an 8% increase in Alzheimer’s risk.

Obstructive sleep apnea (OSA) can keep people from spending that 120 minutes in REM.  Each time there is an apneic event, the sleep stages reset to stage 1 the cycle starts over.  Therefore, the person may not get to stage 5 or REM.  This can also happen to people who use CPAP; if there is a leak or something else which causes an arousal, the sleep stage can also be reset to stage 1 resulting in a lack of REM sleep. 

There is still a lot of study that has to be done to make sure that it is not the dementia that is causing the sleep disturbance and not the other way around.  But it is safe to say that everyone should do everything they can to make sure that they are getting the right amount of sound sleep.

Studies also show that people who sleep for over 9 hours every night have twice the risk of developing dementia within 10 years when compared to people who sleep for under 9 hours every night.

OSA is treatable.  Make an appointment for a free consultation to discuss your questions and see the treatment options that are available as well as how you can find out if you have OSA.  Call our office at 208-667-4551.