Seems that would be a good thing, but has the doctor commented on it? I've heard of apnea being suppressed with diet changes etc. Do you think that could have happened with her?
Do you see or hear anything from her when she sleeps that would tell you something is interfering with her breathing these days...something that would indicate an apnea problem?
Sometimes, maybe often sleep apnea occurs in people who are obese. A change in diet that reduces someone's weight could correct sleep apnea. In my wife's case, the sleep apnea may have been the result of her having an enlarged thyroid. An enlarged thyroid can restrict the airway thus causing sleep apnea.
Has the doctor commented on what? The fact that she sleeps part of the night in a chair as opposed to laying down in bed? Not really. Her primary care physician and the nephrologist both asked her about using the CPAP for quite awhile. When it became obvious that she wasn't going to use it, they've both let it go. Realistically, while not using a CPAP when it might help with breathing and sleep can be life threatening, my wife has much more serious health issues going on then this and has had for a least 10 years.
She doesn't sleep well, but then her sleep patterns have been messed up for quite awhile. It's better since she started dialysis, but she generally sleeps about 12 to 14 hours in any 24 hour period. The quality of that sleep is not great for a number of reasons. When I've listened to her breathe while sleeping lately, it has been pretty regular.
You seem to be trying to figure out how to make her well. If you can do what many doctors have failed to accomplish over the last few decades, it would be amazing. My wife has never had really great health her entire adult life. Some of this is due to her not taking good care of her health and mostly, it is just crap genetics.
Maybe we are all taking the easy way out, but her specialists and regular doctors are just concentrating on making her feel as good as possible. She's feeling a lot better since starting dialysis. The doctor told her she would continue to feel better and better over the next several weeks. This being said, there is no medical reason that suggests her kidney failure will go away. Dialysis is doing the work her kidneys no longer do. As I mentioned she also has congestive heart failure. That doesn't get better with time or treatment either.
Read about chronic stage V kidney failure. There are three ways to deal with it. One is to simply do nothing and die over the course of several weeks. Another is to have a kidney transplant, which my wife cannot do because she would most certainly die during surgery. And lastly, go on dialysis for as long as that works which might extend your life some, but won't resolve the kidney failure.