So many of us are told by doctors that a very low/suppressed TSH will probably cause AFib or osteoporosis, and we have our dose reduced.
We maintain that it's a high/over range T4 and T3 that may do that, not the TSH level. We say that as long as T4 and T3 are well within their reference ranges, we are not at risk.
I asked Prof Dayan, Prof Bianco, Dr Midgley, Dr Toft and Prof Pearce on various media, and they all agreed. I hope these quotes might help others to fight their cause.
Sorry the text is small but I can't add this as a PDF.
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TaraJR
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I'm pasting all the text here, as it may be easier to read:
Are problems caused by suppressed TSH or high T4/T3? TJR, September 2024
Leading endocrinologists, well-known in UK and abroad, were asked by a co-lead of ITT Improve Thyroid treatment patient group: “Is it a suppressed TSH itself or high/over range T4/T3 themselves that can lead to problems eg osteoporosis or atrial fibrillation?” They all said it is the T4/T3 levels…
Prof Colin Dayan:
"T3 often suppresses TSH. You can take enough T3 which doesn't suppress TSH. But if that's the only way to feel well, you may want to do that, though it's not ideal. It’s a trade-off … low quality of life versus taking a risk. It is a low risk. At the end of the day, it's only T4 and T3 that matter. TSH doesn't matter as it's not acting on tissues. But we use TSH to judge on average what is happening in tissues. It's the levels in the cells that matter."
Zoom meeting
Dr John Midgley B.Sc (Leeds) D Phil (Oxford)
"TSH will often be suppressed when taking T3 because, molecule for molecule, T3 is about 3.5 times as potent as T4 in suppressing TSH."
Regarding possible increased risks from ‘suppressed TSH’ in studies:
“Tiny increased risks at the lower end of the TSH values cannot be distinguished from zero. Respectable statisticians say that anything below 1.3 should be read as no provable effect.”
Thyroid UK HealthUnlocked Forum
Prof Simon Pearce:
"An interesting question and a subject of debate. It's the T4/T3 really, as bones are sensitive to thyroid hormone levels, rather than a suppressed TSH. But a US study showed a fully suppressed TSH can lead to some osteoporosis in mice. You should generally avoid both."
The Thyroid Trust webinar
Dr Anthony Toft, leading endocrinologist, past president of the British Thyroid Association
"The appropriate dose of levothyroxine is that which restores euthyroidism and serum TSH to the lower part of the reference range - 0.2-0.5mU/l. In this case, free thyroxine is likely to be in the upper part of its reference range or even slightly elevated – 18-22pmol/l. Most patients will feel well in that circumstance. But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l. This 'exogenous subclinical hyperthyroidism' is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l"
Pulse journal
Prof Antonio Bianco, Twitter 2022:
“The problem in every case is an excess of T4 and/or T3. The low TSH levels only reflect the excess of thyroid hormones. TSH has no effects on the heart. Sometimes, the excess of thyroid hormones is so small that the only indication is a low/suppressed serum TSH.”
“Not the TSH. Except that T3 has rapid kinetics; levels change fast and it is hard to say it is normal. It is high after you take the tablet, and lower several hours after. This makes it harder to track T3.”
“TSH is excellent to make the diagnosis of hypothyroidism. But it is not good to assess treatment with LT4. I am proposing that in addition to symptoms and TSH levels, we also consider T3 levels in patients receiving LT4. After all, T3 is the active thyroid hormone.”
As always in this discourse there is scant reference to those who need a supraphysiological dose of T3 which suppresses TSH, gives a high FT3 reading but with T3 in the serum still inactive. This scares most medics because they don't understand why TSH has dropped off the reference range and they overlook that TSH is a pituitary, not a thyroid hormone. Are these quotes enough to convince TSH devotees that it is not a reliable marker?
Depending on the patient's needs a therapeutic dose of T3, of whatever level, provides adequate T3 to enter the cells ( in some cases overcoming Thyroid Hormone Resistance) and reach the nuclei, and attach to T3 receptors, and finally become) active.....nothing to do with TSH!
The endos all said that "it is the T4/T3 levels".....surely it is the T3 level which is paramount and FT3 testing should return as a routine test, as it was when I was first diagnosed 25 years ago!
Prof Bianco states, "I am proposing that in addition to symptoms and TSH levels, we also consider T3 levels in patients receiving LT4. After all, T3 is the active thyroid hormone.”
Fine words, but useless without action!
Nothing other than a monumental change in thinking and understanding is going to improve thyroid treatment.
Signs and symptoms are hugely important but are generally dismissed in favour of TSH numbers, and sometimes FT4.....rarely FT3!
As Dr Midgley once pointed out, "For the moment mechanical thinking has traduced medical diagnosis".
Yes a similar list with T3 quotes would be useful. No doubt we would be accused of cherrypicking but that’s what Pearce does himself. I bet his TSH comment had to be squeezed out of him. I would love to confront my GP with it. Pearce is the ‘leading light’ in my area, directly spoiling many a hypothyroid patient’s life. So far I have had no problem with my TSH. It’s everything else hypothyroid I have problems with!
I was diagosed in about 1981 and at that time they routinely tested TSH T3 & T4 I had a brilliant endocrinologist and his stand in when away was an Army Mayor who also knew his stuff it's a pity that the GP's and Pharmacists don't have the same knowledge when interpreting results
No they're not obliged to follow the guidelines. Guidelines are just that: a guide. They are not rules. And it says within these guidelines that they do not replace a doctor using his own judgement.
That is just the excuse they use for not using their brains!
I'm in graves remission currently, but have normal T3/T4 , but TSH is stuck around 0.12.As soon as tsh dropped issues with white blood count/nutrophils.
This is a great collection of quotes, so useful to have them all together.
It's a shame it can't be added as a PDF, as I would love to email this to my endocrinologist the next time he tells me (for about the 100th time) that I'm going to give myself AF and osteoporosis with the dose of T3 I'm on.
TaraJR - Endos' quotes on suppressed TSH v high T4/T3
Problems caused by suppressed TSH or high T4/T3?
Leading endocrinologists, well-known in UK and abroad, were asked by a co-lead of ITT Improve Thyroid treatment patient group:
“Is it a suppressed TSH itself or high/over range T4/T3 themselves that can lead to problems eg osteoporosis or atrial fibrillation?” They all said it is the T4/T3 levels…
My quality of life before taking T3 was awful, and I wasn't bothered if I was here or not. Since taking T3 I am vastly better, although my TSH is now suppressed. There are papers showing that the extra risk from a suppressed TSH is small, and I’m willing to take that very small risk. The decision should be a joint one between doctor and patient.
A very low TSH may carry an additional slight risk but, to me, well worth the trade-off against having a decent quality of life. An elevated TSH is as hazardous as a low TSH, or perhaps more so.
Yes, I've been eating recklessly (ice cream, desserts, over eating...) thinking that I can do myself in with a heart attack. Death by ice cream! I'm serious. I took a 90 mg dose of Armour this a.m. instead of my new, depressing dose of 75 mgs, and I'm feeling better. When I was on 90, with a suppressed TSH, and a low range FT3, I had a personality! I had my sense of humor back! I was happy to go to work! I felt great! Thank you for listening.
Isn’t it incredible how your sense of humour comes back? I remember that happening when I switched from Levo to Armour. I’d thought it was just living in the country that had made me lose my wit! 🤣.
This is a terrible thing to say but, if I'm going to die of this disease, I'd rather die feeling great (on the best dose of Armour) than feeling like shit (on the wrong dose.)
I know I need 175 mcg levo to get a tsh of 1 but gp's happy with a tsh of 4.5 so only get 125 mcg prescribed , so after yearly blood test I take care of myself for a good 9 months if I can't get an increase from gp.
My TSH is zero, ie completely undetectable and has been for well over 20 years. I've seen so much panic among local Endos as my TSH is so low and its taken me until recently to discover that my pituitary is failing due to a head injury and encephalitis many years ago. As a result if the low TSH I don't produce any T4 nor could my body convert it so I rely on T3 medication. It been a long and hard fight to get my diagnosis but I can say that I don't have any AFib or osteoporosis problems at all despite a high dose of T3 to keep me on my feet.Heather
I finally found an Endo who listened to how ill I was and was prepared to test all the other functions of the pituitary. When it was clear that they were all low or non existent he then went onto order an MRI from which he could see the pituitary had shrunk. Since then he has started a whole raft of medications to replace the missing enzymes and I feel an awful lot better. My local endos are completely bemused, I have even offered to go and teach them all about how important the pituitary is!Heather
My TSH is always in the 0.03 or lower range which sends some GPs in tailspin and want to drop my dose. One hospital medic documented overdose of hormones on my records for a low TSH and T4 of 15 ! At least my Endo is relatively happy and thinks secondary hypothyroidism despite all pituitary tests on lower end of OK but i get conversation about risks to my heart and bones each time ! . Have just had t3 doubled to 10mcg twice a day and levo dropped from 100 to 50 so need blood test in 8 weeks so am awaiting mini panic as I expect this will have dropped TSH to unreadable...
Agreed. I took a 90 mg Armour pill this a.m. instead of my new dosage of 75 mgs because of "a suppressed TSH #". (I have 120's, 90's in a stash due to NP-ordered dose changes) and for the first time in weeks, I cleaned the cats' litter box room, went outside and dead-headed flowers, fed the birds----all of the things I need to do or enjoy on a daily basis. The NP will hopefully be on maternity leave when I get my next labs, and maybe I'll get to see the Endocrinologist who is a former chemist! Ya think that his chemistry background would make him a better Doctor!
Thank you to all UK ladies on this site for listening to me. I still fall for the things that the Endo's/NP's say about my labs hoping that what they are telling me is right. My new Endo (#7) has a chemistry background. I thought that this would be helpful in his insight, but since my initial visit, when I did get to meet the Endo, I'm stuck seeing his NP. She is about to deliver her baby, so hopefully she'll be on maternity leave for the next couple of months (crossed fingers.) Thank you so much for your input and confidence.
Brilliant …now to find someone with a printer …. ! There’s one doc in particular I’d love to send this to - the one who insisted I lower my thyroxine, ignored my hypo symptoms and unlike my regular doctor did not ask how I felt ..ended up having very high BP, high cholesterol and a stroke.
My TSH is 0.005 and has been for at least 9 years. It causes some consternation with some GPs at review time. I long ago told “them” the GPS and locums that I prefer a life to an existence. I take T4 100mcgm and T3 15 mcgm and my results are both around 75% through the range.
I have tried to educate the medics that TSH is a pituitary hormone and it’s the correct levels of T4 and T3 that keep me well.
Thank you TaraJR for the quotes. I shall print off so that I have the info to hand for when the last sensible GP leaves my practice.
Tara, thank you so much for this information. It is very timely for me.
I've had a few bouts of Atrial Fibrillation over the past year. The GP wrote to the endo about it and they have suggested I reduce my T3 from 20mcgs daily to 10mcgs daily. I have never seen this endo. I am heterozygous for DIO2 gene and therefore I have difficulty converting T4 to T3. I have been on T3 since January 2018.
The head of the department who I have seen is obsessed with TSH and is very concerned that it is very low or suppressed. Despite repeated arguments he isn't happy with my TSH. I have had investigations for pituitary issues and they were clear. He just cant seem to accept that a low TSH is a direct result of having adequate T3.
I have been on aromatase inhibitors for the past 4 years and I believe it's is the cumulative effect of this depletion of oestrogen which has caused my AF and it is significant that the AF bouts have been on extremely hot days. A retrospective study in December 2023 showed that ladies on hormone blockers had a 25% risk of AF. Armed with this information, I requested to go on Tamoxifen (which puts me at a very slightly higher risk of recurrence of the cancer), instead of the aromatase inhibitors. I have not had a bout of AF since I changed, although it's only been since August.
This information together with the AI study, should help me with both the GP and the endocrinologist. I have not reduced the T3 as I have no wish to live a half life in my latter years.
I am very grateful for this information Tara. Thank you so much.
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Can doctors be persuaded to check free T3 and free T4? Or just TSH?
Can you be hypothyroid with normal Free T4 and Free T3 just Tsh high? 
T4 too high when TSH in range. Please can you look at my results?
Why would my TSH remain out of range if my T4 and T3 is dropping after meds increase? Please can you advise?
