I just did a brief google search on this subject, and found a few references. Of course you know that anxiety, panic attacks, and various sleep disorders go hand in hand with a bad thyroid. So there is some evidence that sleep paralysis might too.
I found these by entering "sleep paralysis" + thyroid in the search bar.
"We can complain because rose bushes have thorns, or rejoice because thorn bushes have roses." Abraham Lincoln