It is not directly related to AS, but heavy people are more prone to developing it, go to your Dr. and a cutting cycle is a REAL good idea anyway. How much do you wiegh? The condition seems weight related because when you sleep your so relaxed that even though your brain sends the signal to your chest muscles to inhale, there is a lag time between the brain and your diaphram to inhale, therefore the delay effect.
SEE YOUR DOCTOR, this can really kill you, it puts a strain on your heart. By the way what is your Bp? No shit Bro see your doc, the wife is right on this one.