I also have sleep apnea, and I guess that actually many people have some form of sleep apnea, but they don't actually know it, in the past people would have a heart attack and didn't knew it could come from this, sleep apnea is serious.
I can say for sure that sometimes during heavy sleep apneas that I have new T's that come and go, or get louder, so there must be some kind of relation. I read that the lack of oxygen can cause hearing issues as the cochlea is a very fragile organ, but sleep apnea also affects many other organs like brain damage. I'm otherwise in very good physical condition, can run a 2 hour jogging without issues, never smoked, weight is perfect, besides hearing issues and food allergies ... I have however tons of stress and anxiety which seems also to worsen when I have bad nights. So I dont have the profile for sleep apnea, but recently during an examen with a camera, the doctor found that mine is related to a few issues inside the mouth (soft palate placed too low) and too large tongue, tomorrow I'll have a 2nd surgery to improve this and probably a 3rd one later on. My doctor said that probably after the surgery my T will maybe also improve as I'll finally have a real sleep, something I never had since more then 16 years.