Hyperthyroid without physical signs?

[stevehecht]

I had a total thyroidectomy in June, 2003 with a Stage 1 papillary cancer. I had an initial treatment with radioactive iodiine and yearly scans since, with nary a sign of a thyroid cell anywhere. My doc has kept me on 175 mcg (I weigh 165 lbs., 57 y.o.) of Unithroid and has kept my TSH <.05 throughout. My 1/29/08 Free T4 was 2.1.

My lab numbers (TSH, free T4) have been rock solid. Over the past year I have noticed very uncharacteristic signs of anxiety and insomnia. I keep mentioning this to my endo but he ignores it. I know he wants to keep my risk of CA recurrence as low as possible, but last fall he declared me "clean" after my third negative scan. My physical examination for hyperthyroid is negative except for a leg tremor. Can anxiety/insomnia be an accurate indication of hyperthyroidism without other physical signs?

I do not want to deal with this anxiety forever, and I do respect my doctor very much and would like to remain his patient. At this point I'd like to ask him to let my TSH get up to .1 and thereby reduce my Unithroid. OR, I'd like to switch to Armour Thyroid and see how I do on that--but I'd have to change endocrinologists to do so.

I've read that symptoms of anxiety and excessive tension can be alleviated with Armour. I'll be seeing my doc in two weeks and I want to talk to him then. Do you have a suggestion as to which option is preferable: Raising my TSH level (dropping my Unithroid dose) or switching to Armour?

Thanks in advance!

[Mark Lupo, M.D.]

You are probably on too much unithroid.  With a stage I tumor and no evidence of persistent or recurrent disease, the target TSH is about 0.2-0.5 given your age and being male -- if you were female the risk appears to be lower and target TSH is 0.3-0.8 for low risk women (particularly if diagnosed younger than age 45).  There is still more research to be done on this topic, but given your description of the cancer and your symptoms of anxiety and insomnia, a dose decrease appears appropriate.  Would avoid armour for two reasons in thyroid cancer -- 1) the TSH may not be consistent on armour and 2) the pig thyroglobulin may be detected on blood tests and confuse the follow-up.

Yearly nuc med scans are not part of routine cancer followup anymore. We rely on highly sensitive thyroglobulin (Tg) levels (assuming your Tg-antibodies are negative) AND high-resolution ultrasound done by a physician trained in spotting suspicious lymph nodes or other lesions....

[stevehecht]

Thanks for the reply, Dr. Lupo. I came to the same conclusion, that I should be on the low end of the normal range for TSH. I will bring your reply to my endo, along with several peer-reviewed articles that support that approach. By the way, I received a nuclear scan only for the first year or two post-op, and then the Tg scan has been done after that.