I had the same concern because I have sleep apnea. I am one week post op and that was my biggest concern about the surgery. The doctors put me at ease by telling me that most overweight people have undiagnosed sleep apnea and everyone is fine. My suggestion is make sure you do the two day clear liquid fast before the surgery and make sure you dont eat or drink after midnight the day before the surgery. If you stay in the hospital make sure you bring your c-pap machine.