Repeated thyroid bloodwork - is Graves confirmed?

[rlosab]

Dear Dr. Lupo

I had originally posted 2 months ago being confused about my thyroid condition (my post http://www.medhelp.org/posts/Thyroid-Cancer-Nodules--Hyperthyroidism/Confused-about-differences-in-opinions-about-my-thyroid-condition/show/1719950#post_7876205).

2 months later, on June 14 I redid the bloodwork (I have never taken any anti-thyroid meds). Here are my new results alongside normal ranges:

TSH < 0.01
FT4 < 25.9  [12.0-22.0]
FT3 < 7.7  [2.8-7.1]

In essense, my thyroid hormone levels have improved spontaneously since my first bloodwork on February 23 (TSH 0.01, FT4 33, FT3 not tested). I did not have antibodies tested this time. Last time my abTPO and TRAB were both negative while abTG was 289 with the normal values up to 115.

The questions I currently have are:

1. does the fact that I am still slightly hyperthyroid after about 4-5 months confirm that I have Graves desease? This all started with a slightly retracted upper left eyelid on December 28-30 with no other symptoms. The eyelid retraction has resolved completely on its own around mid May.

2. shall I wait for the thyroid hormones to improve spontaneously (since this seems to be the trend) or shall I start taking anti-thyroid medication?

3. Even though my bloodwork shows I am slightly hyperthyroid, for the past 1-2 months I have been feeling cold, constipated & my resting heart rate has come down to 56-63. If my tests had not clearly shown hyperthyroidism I'd be insisting that I am hypothyroid. Are such discrepancies between the thyroid bloodwork & physical signs normal? Could I be dealing with rT3 dominance? Could these be effects of 500mg L-carnitine I've been taking a day?

4. I can't help wondering if this could still be silent thyroiditis. Does the thyrotoxicosis in silent thyroiditis always resolve in max 3 months? I seem to have googled somewhere that in rare cases it could last up to 12 months.

I can't thank you enough for your attention!

Kind regards
Rosa

[rlosab]

Dear Dr Lupo

I just redid the bloodwork on August 9. Here are my current results: TSH < 0.01, FT4 17 (range 12 to 22). As previously mentioned, I have not taken any antithyroid drugs although my doctor had prescribed them to me in March. As a reminder, following were my thyroid results without any treatment:

February 23:               TSH 0.01, FT4 33 (range 12-22)

Begginning March:      abTPO 12 (<34 negative), abTG 289 (<115), TRAB <1 (<1.8 negative)

June 14:                     TSH < 0.01, FT4 25.9 (range 12-22), FT3 7.7 (range 2.8 - 7.1)

August 9:                   TSH < 0.01 FT4 17 (range 12-22)

My TSH is still <0.01 but I have already been told that it may remain low for some time even after hyperthyroidism is resolved. What do I do now? I have an appointment with my endocrinologist on August 14 but I would like to know what shall I ask for if anything.

Thanks a lot Dr. Lupo.

I greatly appreciate all your support on this forum.

Rosa

[Mark Lupo, M.D.]

The iodine that you took last year was a higher dose been the usual daily recommendation of 150 µg however it should be well out of your system and not currently impacting the labs.  A test of urine iodine status may be helpful to exclude continued excess iodine as a cause of the current symptoms hyperthyroidism

[rlosab]

Dr. Lupo, I thank you very much for your clear response. I just found out one thing I had not thought of before. In August-September 2011 I took some herbal supplements that I did not know contained Kelp (between 200-400mcg iodine). No one in my family has any thyroid or autoimmune illnesses and it just seems very coincidental that I developed thyroid problems about 2-3 months after exposure. As a side note, I was born and grew up in a country with mild to moderate iodine deficiency (up to 16 years of age). My questions are:

1. It is not clear to me if anyone, even without an autonomous nodule, can get hyperthyroidism with increased iodine consumption. If yes, is it any different from Graves desease?

2. Is it possible for thyroid issues to occur 2-3 months after excessive iodine intake?

3. are 200-400mcg of iodine in addition to normal iodide contained in foods and table salt sufficient to cause thyroid hyperfunction in susceptible individuals?

4. what's the prognosis? unfortunately, very little information is available on the Internet with regards to such a condition. I have read that it can take many months for the iodine induced hyperthyroidism to resolve. If iodine exposure caused Graves desease in my case, is it possible for it to resolve spontaneously once iodine exposure has been reduced? how long should this normalization take? I have not taken the kelp containing supplements since about end of September - beginning of October. I do however eat the table salt, dairy, eggs and other products containing iodine that I have always eaten. My first symptom was a slightly retracted left upper eyelid in the end of December (resolved on its own in mid May). My hormone levels have been gradually reducing. Could it be related to kelp supplements and is my outlook good if I avoid further iodine supplements?

Thank you Dr. Lupo once again for your kind help.

Rosa

[Mark Lupo, M.D.]

The T4 and T3 are still high suggesting against a transient thyroiditis which would have improved over a 3 month period.  Would consider an I-123 scan to confirm a diagnosis and screen for a functional nodule as the Graves' antibody was normal (neg TRAB).   Ultrasound may also be helpful if there is a concern for a nodule.  The levels seem to be improving, so if you are without symptoms, then close observation and further work-up is reasonable. The carnitine is not likely to be contributing.
Don't worry about rT3 -- it is not clinically useful in such situations.