<<Disclaimer: Verify this information before applying it to your situation.>>

To my knowledge, Thyroid Disease is an autoimmune disease, like
Diabetes and people who get Celiac have a pre-disposition to get
other autoimmune diseases. Just because you have Celiac does not
mean you will definately get the other diseases, but the chances are
greater than in the general public. I am not aware of anything you
can do to prevent this, as it's a matter of genes you've inherited
and conditions unknown that are a precurser.
        If anyone has more knowledge on this subject, please feel
free to add, or correct me if I'm wrong.         Lynn in Omaha