This shows that the use of T3 in treatment is becoming more and more up for discussion (and a reasonable bit of positive thinking here from a US thyroidologist).
THYROID
Volume 32, Number 6, 2022
DOI: 10.1089/thy.2022.0196
Liothyronine Use Beyond Replacement Therapy, with Caution
Francesco Saverio Celi
Cue GP's with 'puzzled' expression ,
" No , you cant have T3 ... you might get a heart attack and die .... erm .. unless we give you T3 which might help you get better from the heart attack.... " .
Exactly so!
Exactly. Does that make any sense? Instead of taking preventive measures. They wait for disasters to happen and then the will give T3 knowingly that T3 is so vital for the heart muscles and more. The heart is a muscle. The heart has a large receptor sight for T3.
Like cats on a hot tin roof! lol And not just GPs specialists too.
I do wonder what is the point of all these studies and trials when they are so limiting and not continued on. All they then serve is to cloud the issues further.
And most trials are aimed at thyroid meds to help other conditions, if they focused on helping those with thyroid issues how much of these other conditions would be eradicated?
Like most meds if you need it you need it, adverse events usually when either not needed or not correctly dosed.
Confuse even more.
Are you going to print that out for your GP? That (incidentally) I heard is head of training at the surgery! 😂😱 Guffaw!!!!
Is there a link please 😬
The paper is available through the TUK archive
There have been a number of studies into 'low T3 syndrome' and cardiac outcomes but as far as I know this is the first intervention study in humans. From what I've see so far (I don't have cardiac knowledge) the state of the art is "we don't know". It's good that some research is being done although I suspect short term T3 therapy for cardiac and other serious trauma is a very long way off.
There is much more evidence for long term cardiac benefits of T3 in hypothyroid patients, see my earlier post healthunlocked.com/thyroidu... . Levothyroxine monotherapy is harmful - regardless of whether patients feel or do better on combination therapy. I've changed my view on levothyroxine monotherapy, I now believe it should not be routinely used.
Celi seems to be one of the better endocrinologists. He did a study that showed liothyronine is about 3x as potent as levothyroxine ncbi.nlm.nih.gov/pmc/articl... . Previously, endocrinologists had assumed L-T3 was 4x or 5x as potent as L-T4 - based on the relative potency of T3 and T4 in the blood. Most comparative studies have been based on this flawed ratio. This is a display of incredible stupidity, school students would realise that the ratio you put in your mouth is not the ratio that ends up in the blood, L-T3 and L-T4 have such different absorption rates and half-lives.
Some endocrinologists claim that T3 poses risks because of fluctuating T3 levels. They provide no evidence for this assertion. Celi did a study ncbi.nlm.nih.gov/pmc/articl... comparing the pituitary response to thrice daily L-T3 and L-T4 dosing. There was no detectable difference between TSH response to either. For those of us with a computing background this is very strong evidence, it meets the requirements of Alan Turing's definition of a thinking machine ("The Imitation Game"), whether we can distinguish a machine from a person. In this case the pituitary could not distinguish L-T3 from L-T4. It is reasonable to assume the pituitary will respond to thyroid hormone at least as quickly as other organs - I think it has to.
Celi did another study ncbi.nlm.nih.gov/pmc/articl... which showed that large doses of L-T3 had no short term cardiovascular effects. Years ago I was on 105 mcg L-T3, I monitored my overnight heartbeat many times, it remained constant throughout the night. It was too high because I needed high hormone doses. This disproves the assertion that T3 therapy (even supraphysiological) produces harmful short term effects. Too much hormone, T3 or T4 (especially T4) will lead to long term harm.
Interesting ..but I would dispute your assertion that the T4:T3 ratio is obvious. We’re all different in out reactions and I feel much improved on approx 6-7 mcg T3 split daily combined with 100 mcg T4. Others fare well on just T3 but at 10 mcg daily my heart had such palpitations I felt I was physically moving with the force!
I don’t understand what you are saying. If you mean the relative potency of levothyroxine and liothyronine the Celi studies are the best we have. They compare the equivalence of the effects of the two drugs on TSH. We have to make the assumption that the effect of the pituitary reflects the effects on the rest of the body. This is a reasonable assumption for healthy people. If it didn’t TSH wouldn’t do it’s job.
For hypothyroid patients, those with a simple failure of the thyroid gland, we would expect them to get better if we replace what the thyroid secretes. The thyroid secretes about 6 mcg T3 daily so taking between 5 and 10 mcg liothyronine (which has 95% absorption) should be about right for these patients.
Some patients need higher doses of T3, which go beyond normal levels. I believe the main reasons are due to subnormal TSH secretion (TSH also regulates T4 to T3 conversion within cells) or various forms of resistance to thyroid hormone.
I don’t convert T4 to T3 well. I get palpitations with much more than 6.25mcg T3 daily. Plus my Levo 100mcg daily. TSH has been around 0.02 sine 1999. So I am guided by Free T4 and T3 which of course they stopped testing a few years ago and neurotic doctor kept saying I was overmedicated. And thereby hangs a sorry tale! I was told ratio was about 1:4.
I'm still confused!
In our blod the free T3 / free T4 ratio is usually around 1:3 but it changes over time and between individuals. If a typical fT3 reference interval is 3.5 - 6.5 and fT4 10.0 - 22.0 then average levels would be 5.0 and 16.0. This gives a ration of 5:16 or just under 1:3.
However, they may be referring to total T3 and total T4 in the blood, this ratio is different, I can't remember typical figures.
They could also refer to the ideal ratio in pill form. I think what you are taking is close to this bearing in mind the 'pharmacokinetics', the absorption rates and half-lives of both hormones.
They could also be referring to the T3 :T4 ratio in NDT.
Sorry if all this is confusing. My view is that we should waste too much time looking at ratios. I would target normal blood hormone levels first and if that doesn't work you have to try more or less T3.
Haha .. your’re right I’m not going to waste too much time thinking about ratios ...an approximate 1:3-4 will do me! I upped my Levo dosage with an extra 2 x 25 mcg weekly much to the puzzlement of my doc but Endo seems to appreciate my tweaking. At the end of the day it’s how you feel that matters.
My only worry is being in hospital for some reason and TSH being used as a guideline. I’m thinking of getting a tattoo saying ‘ TSH always low’ maybe with a copy of the graph with my TSH almost flatlining!! So far finding good papers/research on the shortcomings of TSH in ‘non-healthy’ people is proving difficult.
I personally don't like tattoos, but even I am tempted with that idea!
It would be the only one I have ... not sure where I’d put it though!!
Thank you for sharing this interesting research which I will study carefully.
Thank you for this post and the link. The heart and T3 - I have a moral dilemma.
My son's mother in law never seems well, is overweight and had to take early retirement. She is now 65.
During a Christmas lunch, my son's father in law told me that his wife has under active thyroid. A few months later, I mentioned to them that I had done a lot of research on under active thyroid as I too have that. I said that I could give her some tips to feel better, as I had found a brilliant thyroid forum. I am 99.99% certain she is only taking T4.
I was later told by my son that I was considered "very rude" to mention her illness; they considered it a private matter.
This week I have learned that she has had to undergo open heart surgery.
Do I tell my daughter in law that her mother probably won't improve her health whilst continuing on just T4? Or do I keep my nose out?
Write an email with links? People can be strange about their health but I think it was a caring thing to mention your research. What does your son’s mother in law say to all of this as we’ve not heard her side of the matter and people are speaking on her behalf. Good luck ..I don’t think you’ve been rude at all.
I agree with Catseyes235 , very caring act. I often have the same dilemma and I just say my piece and offer links.
I don't think it's rude if the FIL brought it up himself. If it was so private then why would he have shared that info with you in the first place. Your son is probably just embarressed for whatever reason & taking it out on you.
I wouldn't outright assume she needs T3, may just be underdosed on T4 or have other (autoimmune) issues, and I wouldn't phrase in the negative as in "she won't get better if..." I would rather phrase it more along the lines of "optimizing thyroid medication doses and nutrients, often overlooked by many doctors, to feel your best and support optimal health" or similar.
Maybe refer to the thyroiduk charity website, and the forum only secondary, as the organization is more credible to others. There might be wording on the website you could use. And I would give her some time to heal after her surgery first otherwise everyone will be too stressed to hear your message.
Good luck and don't feel bad for caring!
Article describing safety of T3 treatment on heart functionA new T3 derivative shows promise in treatment with T3 and smaller FT3 spikes after taking itVery encouraging performance by a chemical analogue of T3 in stabilising FT3 by those who take T3
An Endocrinologist recognises role of T3 in treatment, plus advice on how it affects vocal chordsThyroid Dermopathy in an Unusual Location
