Sleep Apena and Hypertension - Are they related?

How is sleep apena and hypertension related?  Have taken medications along with an extensive aerobic exercise program in addition to decreasing salt intake.  Doctor sending me for a sleep test. Speculates that sleep apena may be the culprit.  In the initial consultation with Pulmonary specialist, oxygen saturation level was at 84%.  Not sure if that is low or now.  Your thoughts?

[carltonfaulconer]

Your blood oxygen % should be above 95%.  Sleep apnea causes low percent blood oxygen.  Basically you stop breathing several times each hour.  That wakes you up and you are tired the next day.  I stopped breathing an average of 41 times per hour. My sister stopped an average of 100 times per hour.

[jan]

I don't know why, but have read it does cause hypertension and it can lead to heart problems and stroke.