I've been doing a lot of research on the link between PTSD and sleep apnea because I have filed a claim for it. I found several articles, but the most recent one I found today and added to my claim. I wanted to share it with you because it was just published this month.
https://www.mja.com.au/journal/2017/206/6/physical-comorbidities-post-traumatic-stress-disorder-australian-vietnam-war
I'm not sure if this will be the icing on the cake or not, but its worth a try! I hope it helps someone. Thank you all for your service!