This paper shows no effect of low TSH on fractu... - Thyroid UK

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This paper shows no effect of low TSH on fractures, mortality or AF

diogenes profile image

I might have already posted this but if not, it's useful to publicise. This paper shows low TSH has no effect on fracures of any sort, mortality, stroke or atrial fibrillation, but shows increased chance of mortality and fractures with above range TSH. The TSH has only got to get above the upper limit of its healthy range for these relationships to start to become obvious.

CCBYNC Open access

Thyroid replacement therapy, thyroid stimulating hormone concentrations, and long term health outcomes in patients with hypothyroidism: longitudinal study

BMJ 2019; 366 doi: (Published 03 September 2019)

40 Replies

Thanks for posting this.

It says "Evidence was found for adverse health outcomes when TSH concentration is outside this range, particularly above the upper reference value." Is there an increased risk when TSH is below reference range? It seems to imply there is some

diogenes profile image
diogenes in reply to suztango

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.

The paper suggests that there is an increased mortality risk when there is a suppressed TSH, but my understanding is that for those of us without a thyroid gland, a suppressed tsh is ok, and often necessary to get enough T3.

The paper doesn't say whether it included anyone without a thyroid gland. Might it be that this is another paper that is misleading in relation to people without a thyroid gland, as our situation is different from other thyroid patients?

Doctors don't seem to understand that without a thyroid gland our physiology and test results need to be interpreted in a different way.

Hennerton profile image
Hennerton in reply to dolphin5

Absolutely agree and I have had a thyroidectomy. It does state that the study did not take into account why patients were hypothyroid, at which point I realized once again that we are being totally ignored. Why is this? We are not a small number across the world yet seem not to exist for any research. I have asked Diogenes this question in a previous post. There does not seem to be a rational answer.

waveylines profile image
waveylines in reply to Hennerton

What about people who are on a full replacement dose because their thyroid effectively died/ completely defunct?

I always go on what my lovely endo told me -" so long as you keep the actual thyroid hormones in range you cant do harm. The TSH neing supressed is not relevant . " My TSH is always very supressed but importantly my actual thyroid hormones are always in range.

The trouble with some of these research projects is that they do weird things like measuring the TSH only and dont consider the actual level of thyroid hormones. The medical world seems fixated on the TSH......for the life of me I cant see why.....sigh........they've also yet to offer a reasoned and well proven evidential research evidence based on more than one study that is well set up, to prove a supressed TSH will cause harm. Its a political hot potato in the endo world.

High TSH with low thyroid hormones is well known to cause health problems, hence our need for replacement or have they forgotten this!!! ........goodness help us all if they come out with some so called piece of research saying we dont need replacement anymore! They've done it in the B12 world and are now looking at putting people with PA on B12 supplements instead of injections......words fail me.... call me cynical but supplements are cheaper than a nhs nurse giving regular b12 injections.....

Hennerton profile image
Hennerton in reply to waveylines

I wish I knew your lovely Endo. I have an appointment hanging over me to see an endo regarding my T3 from my GP. Obviously he is trying to remove it but there will be a fight! Why are thyroid patients treated like brainless idiots, who are costing the NHS too much money, when billions are spent on obese people who eat too much and never move from the television. Hope that does not offend anyone but I am tired of fighting my corner in thyroid matters.

waveylines profile image
waveylines in reply to Hennerton

Sending you big hugs Hennerton. I dont know why we get treated like this.

My GPs seem to be taking the approach that I know better than they.......amazing! Maybe all the stropping & broken record is finally paying off......or maybe its the dramatic improvements that occured, first on optimal thyroid treatment and latterly when I took B12 into my hands & gave myself injections.......they were totally amazed at the improvements that occurred.

Sadly my lovely endo has am back at the mercy of the mass TSH far left alone... xx

Hennerton profile image
Hennerton in reply to waveylines

My GP is like yours was and has apparently written to the endo stating that she wishes me to stay on it but we all know that carries no weight when CCGs are trying to save money in order to bale out the people who never try to help themselves. We are an easy target - polite and reasonable. Time to start making a big fuss, I think!

loueldhen profile image
loueldhen in reply to waveylines

Which CCG are you in?

in reply to Hennerton

I understand where you are coming from, but, ironically, hypothyroidism can make us obese and unable to move from the television!

At worst (though still classed as "Subclinical") I didn't have the mental or physical energy to even switch on the TV or do anything else - even think. Making a cup of tea was a major operation, even when I managed to get up and go to the kitchen. Even now I get periods of tiredness and mental lethargy most days.

No doubt others have or are still experiencing the same.

It's a catch 22 isn't it.

Hennerton profile image
Hennerton in reply to

I am sorry you have had such poor treatment and please understand I am not referring to thyroid patients, whom we all know may be struggling to get through each day. I am talking about the “Let’s have another takeaway with a bucket of icecream to follow” section of society. Millions of them are now dragging down the NHS, including young children, yet we are being denied a medication that will change our lives for the better and which through greed on the part of the pharmaceutical companies, is now too expensive for the NHS to consider supplying to us. Where is the justice in that?

in reply to Hennerton

'please understand I am not referring to thyroid patients, whom we all know may be struggling to get through each day.'

Yes, I know.

'I am sorry you have had such poor treatment'

I was talking about before starting on thyroid meds a couple of years ago. Compared to most here my treatment has been quite good, except for a few blips.

Still trying to find my 'Sweet spot' with thyroxine though. Maybe an endo appointment next month will help get to the root of the problem, unless he's a 'TSH-only' bloke

Hennerton profile image
Hennerton in reply to

I think you have probably had good treatment, as you say, because you are looking out for yourself all the time- an absolute necessity. I trusted my GP for several years after my thyroidectomy but eventually realised I was getting worse and worse. I bought Dr Peatfield’s book and my eyes were opened. Since then I have fought for everything to keep me well but it is not easy and is made worse by the new T3 guidelines. It should not be like this. Would they take away insulin from a diabetic? I do not think so but this other side of endocrinology is like night and day to thyroid patients.

in reply to Hennerton

I’m just about to eat too much and watch TV 🤔 sorry to hear you are being challenged over your T3. It’s horrible to have to argue for something that restores your health. The power dynamic of you having to justify to someone else what you know about your own body does my head in.

Hennerton profile image
Hennerton in reply to

Thanks, Mike. I do love a sense of humour. Especially at the moment when all is gloom and doom. Keep well and enjoy whatever makes you happy.

in reply to waveylines

Wow what a great endo

This study gives similar results to other studies e.g. . What is interesting is that an elevated TSH is as hazardous as a low TSH, or perhaps a little more so. However, whilst doctors will give grave warnings about a 'suppressed TSH' I've never heard of similar warning being issued about a mildly elevated TSH. The evidence is used selectively.

There are other considerations. For example, some of the patients will have had periods of thyrotoxicity or prolonged periods of hypothyroidism or concurrent parathyroid damage, these affect long term health and so even with perfect therapy they may not achieve the same level of health as the general population.

These studies look at L-T4 monotherapy, it may be that L-T3 carries higher risks. I would expect this to be so, because protective deiodinase mechanisms are bypassed. Some of us need substantial doses of T3, accept a moderate risk and mitigate it with sensible exercise.

I dislike the casual reference to a 'suppressed TSH'. A TSH below the lower reference limit or one that is very low is not necessarly suppressed. It might be suppressed by high thyroid hormone levels, or it might be low due to insufficient TRH stimulation as can occur in a down-regulated axis. Accordingly, a TSH that is low because it is truely suppressed is likely to be assocatiated with more risk that one that is caused by insufficient TRH stimulation.

It would help if we referred to a 'low' or 'very low' TSH rather than using the term 'suppressed'. 'Low TSH' is a statement of fact rather than a presumption. I believe many patients have a down-regulated axis causing subnormal TSH secretion leading to profound deiodinase problems.

Everything in life carries risks. These studies show that the risks are comparatively small and a patient restored to good thyroid health will be able to mitigate risks by exercising and leading an active life. It's about time the proponents of 'evidence based medicine' looked at the evidence.

waveylines profile image
waveylines in reply to jimh111

Totally agree jimh111.

I think the problem is that much research is incomplete and therefore flawed leading to misinterpretation. Rare is the research that looks at ALL the thyroid hormones AND TSH. Why would low TSH be dangerous if the thyroid hormones are balance and in range with no symptoms of toxicity? Wouldnt it make sense that if this is the case the TSH would be low as the body has sufficient thyroid hormones to do well? No one seems to have been able to answer these common sense questions and prove it with good evidential and complete research. Why would anyone conduct research that only looks at TSH in relation to T4? I think politics have taken over and coloured much of what has gone on.....thats my cynical opinion.

jimh111 profile image
jimh111 in reply to waveylines

I agree. TSH can be very useful but it drives me nuts that doctors do not also measure fT3 and fT4 at least once so they can confirm that the TSH is consistent with thyroid hormone levels. No study has ever found a good relationship between TSH and clinical response. TSH can be very useful but not always.

helvella profile image
helvellaAdministrator in reply to jimh111

I dislike the casual reference to a 'suppressed TSH'.

So do I.

An unmeasurable TSH (or one below an arbitrary low value) can be caused by just enough thyroid hormone to make it drop that far. I suspect this could sometimes be something like a few per cent more than a level which would leave TSH in range or at least not in the "suppressed" bucket.

Or by FT4 and FT3 levels that are multiples of the tops of their ranges. (As can occur in Graves.)

It is quite possible that the difference between these two extremes could be numerically larger than that between zero and the tops of their respective ranges.

Yet these two extremely different cases are grouped together and treated as one.

So these low/zero/suppressed TSH results could mean anything from just adequately treated through thyroid storm. So from good to very bad.

Whereas a high TSH (assuming no tumour or other unusual problem) always means inadequate thyroid hormone. And appears always to be bad.

in reply to jimh111

Thank you. My first attempt at reading the paper (not enough energy yet to try again) was confusing because I thought Diogenes was recommending it as a good study!

So, if T3 and T4 levels are good, is very low/suppressed TSH likely to do any harm? If so, in what way? The only thing I can think of is that it might cause downregulation.

helvella profile image
helvellaAdministrator in reply to

Even a study which has flaws might contain useful bits.

The lack of impact of low TSH, despite the subjects NOT being divided into groups by cause, is quite strong.

in reply to helvella

I thought it says that low/suppressed TSH could raise the risk of AF and fractures. But, as said, I don't have enough mental energy just now to take it in properly

helvella profile image
helvellaAdministrator in reply to

diogenes replied earlier with this:

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.

Yes - there is a very small increase with "suppressed" TSH. But given that group would include people with substantially high FT4/FT3, and this lack of statistical significance, it is the other end of the TSH range that is important. Primarily 4.0 upwards.

in reply to helvella

Thank you, I missed that somehow, and it is a personal concern at the moment.

Several weeks ago my TSH tested as 0.005, with T3 just under top of range and T4 quite a bit over. I dropped the dose of Levo slightly, and waiting to test again and for an endo appointment (the first) at the beginning of April. So I'm trying hard to get my facts straight for the endo.

So we will see...

helvella profile image
helvellaAdministrator in reply to

It is so very easy to miss things - there is a lot of traffic in this forum and sometimes even on a single thread.

jimh111 profile image
jimh111 in reply to

I think it's a good study although it is a long time since I read it. It is a retrospective study so not as good as a well run prospective placebo controlled study. Consistent with other studies it shows a very low TSH carries similar levels of risk to an elevated TSH in levothyroxine treated patients. Even so these relative risks are pretty small except for patients with a TSH greater than 10. To be honest I wouldn't worry about them there are plenty of much greater risks around such as poor diet and smoking. I think this is the point diogenes is making, a very low TSH carries little additional risk, well worth the trade off of having a life. I just try to keep myself on the minimum effective dose of L-T3 (because I need a high dose of around 50 mcg + 50 mcg L-T4). Being able to run around and get fresh air does a lot more for my health than a 'normal' TSH.

in reply to jimh111

Thank you

Thank you and I heartily agree with your final paragraph.

On my reading of the paper some

of the points already mentioned above came to mind. ie a fixation on TSH readings with no regard to actual thyroid hormone levels. The low TSH results that showed a small link to poor outcomes could have been from patients with elevated free T3? There is no separation of patients with low TSH but free T3 within range. Interesting however that strong correlation of poor outcomes with higher TSH. A handy reference to quote to the GP when they spout low TSH related to atrial fibrillation and bone thinning.

waveylines profile image
waveylines in reply to Hoxo

But higher levels of TSH have already been linked in this way with proven consequent effects such as heart disease -that is the basis of the need for treatment. Not news at all but bonkers mentality by an obsession on the idea that if the TSH is in range no matter the other thyroid levels that frequently arent checked you are 'fine' and dont need an increase or treatment.

The TSH ranges are also pretty arbitory. Why 10? Wheres the solid band of medical research to substantiate this? Its not there!!! The political madness/obsession has created a dogmatism that isnt based on good medical practise and evidence.

I personally think that is why the treatment of hypothyroidism hasnt improved over the years or developed but infact has worsened, leaving people in poor health with increasing damage to thier bodies with either no treatment, inappropriate treatment or insufficient treatment. Its scandalous.

Sorry will get off my soap box now! Lol... 😤😳😊

Hoxo profile image
Hoxo in reply to waveylines

My older neighbour has had a sub total thyroidectomy and is now on a small dose of Levothyroxine She is rapidly gaining weight - prob about 5 stone and is now obese, has heart issues, recurrent infections, severe depression etc etc. I tired to help her and ask what’s going on. She said her GP has said her symptoms are not thyroid related as her TSH is in range and that he said they ‘like to keep TSH around 3’. It’s scandalous negligence and abuse. I’ve given her information but she’s so brain fogged and of the trust doctor era I don’t know what else to do.

in reply to Hoxo

It's criminal. Does she have any relatives you can contact who might help fight her corner?

Hoxo profile image
Hoxo in reply to

No sadly. It’s an awful situation that I’m sure is being repeated all over the country.

waveylines profile image
waveylines in reply to Hoxo

Oh bless her! The ignorance of doctors is mind blowing and plain dangerous. So sorry to hear this. Would she consider seeing someone privately a thyroid uk friendly doctor maybe. Must be awful for you to watch her getting worse like this.

Redlester profile image
Redlester in reply to Hoxo

And, of course, they will be able to give her a bag of prescription medications to deal with all those knock on medical problems she has developed because they haven't properly addressed the fundamental underlying thyroid problem that she has, and probably give themselves a pat on the back as she leaves her appointment with them on a job well done.

'We found no difference in mortality rates within the recommended normal TSH range of 0.4-4 mIU/L; however, mortality was higher in the lowest TSH category (<0.1 mIU/L) and for concentrations above 4 mIU/L.'

'Some evidence existed of reduced risk of stroke/transient ischaemic attack in women and patients aged over 65 years when TSH concentrations were within 3-4 mIU/L, but this was offset by a higher risk of atrial fibrillation in those aged over 65 years.'

I extract two statements and wonder why, if problems become apparent when levels go beyond 4 mlU/L, treatment is only given when levels are over 10 mlU/L?

I realise the researchers are referring to patients already being treated, but surely it applies to those not on treatment and whose levels are between 4 mlU/L and 10 mlU/L i.e. subclinical?

Flabbergasting that we sat there at the BTF NICE guideline presentation with the same old ‘AF and osteo risks of suppressed tsh’ being trotted out by an author of the paper!

Treepie profile image
Treepie in reply to loueldhen


loueldhen profile image
loueldhen in reply to Treepie


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