Reversed T3?

[Gsp177]

Has anyone here been diagnosed with reverse T3 dominance?

[Clutter]

GSP, my endo told me NHS don't test rT3 so I'm not sure how they would diagnose it. I stopped T4 for 8 weeks but was still very ill on T3 monotherapy and stopped T3 too, for 4 weeks. I felt some improvement within a few days and all symptoms (and there were many) cleared within 2 weeks of no meds. In hindsight, I suspect it may have been rT3 but there was no diagnosis. I've not had problems since resuming T4+T3 combination.

[Heloise in reply to Clutter]

Clutter, had you seen this before? I found it very informative.

stopthethyroidmadness.com/s...

[marmaris in reply to Heloise]

This is an extremely informative article Heloise, I enjoyed reading it, thank you.

[Heloise in reply to marmaris]

You are welcome, marmaris. It shows how much we still have to learn about the iodine controversy.

[Heloise in reply to marmaris]

Oh, you may have been talking about the reverse T3?

[humanbean]

I've never had a diagnosis from a doctor about reverse T3. However, last year I had a full thyroid panel done by Genova Diagnostics which included reverse T3 and my level was almost 50% higher than the top of the range. At the same time my free T3 was in range, but quite high in range. I felt diabolical.

[Heloise in reply to humanbean]

stopthethyroidmadness.com/s...

I posted this to all three of you. I found it pretty interesting. All the links are in the header.

[Heloise]

A lot of info on reverse T3: stopthethyroidmadness.com/s...

[marmaris in reply to Heloise]

I wish that my Endo would test have asked. Cannot afford it privately and even if I could how would the Endo's interpret it? They don't seem to think that it is important???????

[jimh111]

My knowledge of rT3 is limited, please bear in mind. rT3 increases in cases of 'non thyroidal illness' (used to be called 'euthyroid sick syndrome'). This can be caused by major trauma or illnesses such as depression. rT3 is produced by type-1 deiodinase which increases with elevated fT4. rT3 is also produced by type-3 deiodinase which increases with cellular fT3 levels. So if you are taking T3 or T4 containing medicine and it's elevating your fT3 or fT4 levels you can expect rT3 to go up (more so if you are taking levothyroxine).

rT3 blocks thyroid hormone action by competing with fT3 for binding sites. I haven't studied this enough but I've never seen anything that tells you whether rT3 is bound to serum transport proteins such as TBG. Is the rT3 assay a measure of free reverse T3 or total reverse T3? I don't know what the relative binding affinity of rT3 and fT3 are. How much rT3 do you need to reduce the activity of fT3.

What is known is that rT3 can be a good indicator of non-thyroidal illness, it can help confirm it. You should know anyway if you have a major illness, physical or psychological.

I would disagree with the endocrinologist approach that if there is non-thyroidal illness you should just leave it alone. Obviously if the patient is recovering from the short term effects of a cardiac event or burns it's probably best not to alter any thyroid treatment (or start it) until they have recovered. But if the patient has long term non-thyroidal illness it seems to be basic common sense that they should be medicated and not left indefinitely in a hypothyroid state. In which case their medication should contain T3.

Given the above I personally cannot see any benefit in paying for a rT3 assay. They are expensive and I can't see what you can gleen from them. As far as I know nobody knows what use they are (other than confirming what would be a very obvious and serious non-thyroidal illness. I don't want this to be discouraging, it's just my view that you're better off paying close attention to your signs and symptoms and your response to T3 or T4 medications.

[flatfeet1 in reply to jimh111]

Hi jimh111, are you saying that an RT3 test can confirm a psychological illness ?

[jimh111 in reply to flatfeet1]

I guess it can confirm a psychological illness, but note I really do mean confirm and not diagnose. rT3 increases if you have high thyroid hormone levels or if you suffer major trauma or due to other causes such as depression or starvation. But it comes back to the question "what use is a rT3 assay?". As far as I can see you will know if you have high fT4 or fT3 levels, you will know if you have suffered a major trauma and you will know if you are depressed or have eaten next to nothing. Do you really need to spend money to confirm this?

I don't want to push too hard on this since I have little understanding of rT3 and have yet to find any paper that tells us what use the assay is, other than for research. What I have written is at the limit of my knowledge on the subject so feel free to check it out.

[flatfeet1]

That's interesting, thank you for this.

[Heloise]

thyroid-rt3.com/backgrou.htm

stopthethyroidmadness.com/r...

This is what I meant to reply to reverse T3.

[jlovell88]

I had many years of t4 which left me in a zombie state. I was on at least 250 micrograms of t4 and feeling worse when the level increased. Finally I went to an expensive doctor who ordered a rt3 test. My medical insurance refused to pay although the test cost only $15. The level was high and I started taking t3. That made me feel good, but raised my blood pressure. Finally I found that the level for total replacement is 1.66 microgram per killogram. Since I weigh 100 kg. I set my dose of t4 at 175 microgram a day. My TSH comes out high on this dose, but I feel the best that I have in 40 years. This seems to be the best that I can do given that a higher dose of t4 or any mixing of t3 seems to cause worse problems. I think that the feedback loop of tsh may be distorted causing the tsh to be inacurately high.