Poor Conversion continued

[Rambling9]

Hi - see below for response from the local endo to my GP (after he asked for advice re trial of T3 as I have dud deiodinese enzymes which mean I'm a poor converter of T4 to T3)

In brief I have Hashimoto's and many symptoms of hypothyroidism despite taking T4 and dose being increased to drag up levels of T3 to just the lower level of 'normal'

I've got the name of a good endo (private and NHS) recommended on here plus by someone else too and I've emailed to request a ball park figure for consultations plus T3 trial as I don't think I'm going to get anywhere locally!

"I would still persevere with the Thyroxine. I appreciate that her conversion of T4 to T3 may be impaired, but I think that the best way to get more T3 is to give more T4. Increase the Thyroxine in 25mcg increments until the TSH is 0.1 - 0.5. Lower than this increases the cardiovascular and bone risk,; It does not appear that Liothyronine is prescribable in SWL for indications outside thyroid / parathyroid cancer and depression in any case.; If she wants to buy T3 herself then it would be best to use this alongside thyroxine - Cutting back the dose, but keeping the emphasis on the Thyroxine, and giving the Liothyronine at the lowest dose twice daily."

I also have a cardio appointment soon so I will try and get them on board re a trial of T3

I'll ask the GP if they will continue a prescription for T3 if it's recommended after a trial

Can anyone spot anything else I should ask or be aware of?

Many thanks

[greygoose]

I think you should be aware that this endo doesn't know much about thyroid:

I think that the best way to get more T3 is to give more T4.

Past a certain point, it isn't the best way if you're a poor converter, because when the FT4 reaches a certain point in the range, it starts converting to more rT3 than T3, and the FT3 level can stay static or even reduce.

Depending on exactly how well you convert it could take a lot of increases, taking the FT4 way above the top of the range, which we now know increases risk of cancer. So, to avoid that, T3 should be given.

Increase the Thyroxine in 25mcg increments until the TSH is 0.1 - 0.5. Lower than this increases the cardiovascular and bone risk,;

No it doesn't. TSH has nothing to do with hearts or bones.

A good endo would know those things.

[Rambling9 in reply to greygoose]

Yes this is the local one whom the GP asked for advice - the one I hope to see will be different as comes recommended by two different sources. That's an interesting point about too much FT4 converting to more rT3 - thank you greygoose

[greygoose in reply to Rambling9]

Sorry, thought it was the one you described as good. lol Hopefully he will know better!

[Peyret in reply to greygoose]

TSH has nothing to do with hearts or bones.

FWIW, as always it's all associative (with many degrees of freedom) rather than causal but pubmed.ncbi.nlm.nih.gov/316...

" Long-term TSH suppression therapy was a significant risk factor for decreased bone strength, mainly by increasing bone turnover."

[greygoose in reply to Peyret]

Another research paper that doesn't take FT3 levels into consideration...

[Peyret in reply to greygoose]

Indeed , the study merely details the association of suppressed TSH Vs bone density. However you seem to place great importance on plasma fT3 levels, whereas I believe to a greater extent, fT3 is somewhat irrelevant. The production and action of D2/DIO2 I *think* is the critical driver. fT3 is just what D1/DIO1 dumps into the blood stream to be used in a select few tissues like in the heart.

Do you have a reference to excessive fT4 leading to increased D3 action please? It's an area I know nothing of and find most interesting.

[greygoose in reply to Peyret]

T3 is the active thyroid hormone needed by every single cell in your body. Not just a 'select few tissues', every single cell.

No, I don't have a reference for excessive fT4 leading to increased D3 action. You're talking to the wrong person.

[Peyret in reply to greygoose]

We think we need to differentiate T3 from fT3. Yes cells need T3, peripheral tissues however don't need *f*T3, T4->T3 is done locally by D2.

[greygoose in reply to Peyret]

But the whole point of this thread is that the OP is a poor converter. You cannot test for what is in the cells, as I'm sure you know. So, we have to go by blood tests. And, experience and research shows us what poor conversion looks like in blood test results. And as Free T4/3 are the only forms the body can use, that is what we look like. Perhaps you would like to share a link to whatever it is you've been reading so that we can all be on the same page, so to speak.

[Peyret in reply to greygoose]

I find this a complex conversation without any clear , documented conclusion.

You started this thread stating the endocrinologist was incompetent.

The OP has no idea if they convert T4->T3 (at a cellular level) appropriately for them. One may look at serum fT4 and fT3 levels and notice that some other people have different values to the OP but without a plausible casual pathway, we know nothing of these results being "poor" or otherwise. *Most* cells don't need serum fT3. Why do we care if the fT4:fT3 ratio is X or Y or indeed Z?

That all said, placebo aside, some people are demonstrably having a better QoL with exogenous T3. If all the relevant national health bodies are using TSH as the controlling metric (yes consensus is a logical fallacy I know), I'm struggling with your assertion that endos who *do* tow the party line are setting their patients up for cancer.

[greygoose in reply to Peyret]

I'm finding it you that isn't clear. I didn't start the thread. The OP is Rambling9. And I didn't say he was incompetent, I said he doesn't know much about thyroid. Not quite the same thing. I just pointed out two ideas of his that most of us would disagree with.

The title of the thread is 'Poor Conversion continued', so one assumes she does know how well she converts.

Why do we care if the fT4:fT3 ratio is X or Y or indeed Z?

Who said we do care? I certainly don't! But the point is, the endo is proposing increasing her T4 to raise her T3, and being that - to all intents and purposes - that is not a good idea, because the latest research has found that long-term high levels of FT4 put you at greater risk of cancer. And saying that is not the same as saying that the endo is setting his patient up cancer! For goodness sake!

And your last paragraph is gibberish, anyway. Who's talking about placebos? And I do know that taking T3 gives a better QoL because I'm on T3 only. But the endo is not proposing to give her T3... I'm not going to discuss this anymore because you are obviously just going to twist anything I say and use it to attack. I don't know who you are or what your qualifications are but you don't seem capable of having a reasonable conversation sticking to the subject without saying I said things I didn't or giving any references yourself.

And, if you want to know anymore about the T4/cancer link, see the posts of jimh111 and sort it out with him:

healthunlocked.com/user/jim...