Sorry you didn't get an answer to your question, which is most likely because we don't know, or due to so many repeat and/or similar questions, perhaps it was answered in another post, so you might do a thread/post search.
However, if you haven't already, you might go to the Doctor Thyroid Forum and ask Dr. Lupo at
http://www.medhelp.org/forums/show/120 OR
at left of page almost top, under "Thyroid Disorders" in red click on "thyroid" it will take you to the forum.
If you have posted more than one post per the sites rules for doctors forums, you probably won't get answered. Or if the forum is full and not taking any more questions for the day, you can try another day.
Good luck and Best of health!