why are docs so scared by low tsh?

[JAmanda]

the moment I started t3 my tsh went down to almost nothing and it’s around there at 0.01 still and it seems it’s similar for others on t3. Now, on here it’s said this doesn’t matter but my friendly Endo does worry (about my bones I think) and my new lovely Respiratory Consutant was also worried about my low tsh - i think about my general wellness and ability to recover from a new severe asthma. So what do they know that we on here don’t or vice versa?

[JAmanda]

taking 100 Levo 20 lio

Results

[greygoose in reply to JAmanda]

They don't know anything, and that's the problem! Yes, they do think a low TSH causes heart attacks and osteoporosis. But, that's the result of poor education and misinformation.

One of the things they don't know - or don't understand - is that a suppressed TSH in someone taking exogenous thyroid hormone is not the same as someone with a suppressed TSH in someone with Graves', where the suppressed TSH is due to very high levels of thyroid hormone - T4 and T3. And it's the high T3 that puts you at increased risk of heart and bone problems, not the TSH itself (or lack of it). Someone taking exogenous thyroid hormone is highly unlikely to have thyroid hormone levels that high because it would make them too ill, and they would reduce. But a lot of doctors don't even know what T3 is, or what it does.

In general, doctors are scared of all hormones because they are not educated in them, and don't understand them. We know better.

[JAmanda in reply to greygoose]

Thanks that makes sense

[DippyDame]

How much T3 are you taking?

Combo or mono?

Do you have any symptoms of overmedication?

Might you be taking too much T3?

The following may be of interest...

pubmed.ncbi.nlm.nih.gov/269...

Liothyronine use in a 17 year observational population-based study - the tears study

paulrobinsonthyroid.com/one...

[JAmanda in reply to DippyDame]

100/20 levels above. Thanks for links.

[DippyDame in reply to JAmanda]

If you feel ok on that dose, don't adjust it on the basis of TSH and on any silly nonsense from ill informed medics.

So long as FT3 is within range and symptoms are resolved you are unlikely to be overmedicated

Yours is sitting at 67.57% through ref range so probably about right

Were your labs much lower ( than above) for a time before asthma started....hypothyroidism symptom.

Over time correct medication may improve the asthma

I was diagnosed with asthma a number of years ago....prescribed two inhalers. Improving my thyroid medication resolved my asthma symptoms.

Hypothyroidism caused me numerous problems/ symptoms which improved with appropriate medication....doctors often don't understand this.

My asthma doctor was really keen for me to get my tsh up.

Does your doctor understand that reducing correct medication may ( just may) raise your TSH but that it will likely also increase your symptoms

Good luck!

[Anthea55]

This is what your docs should read - from the Thyroid UK website, Further Reading, 7 myths of hypothyroidism. You will find it interesting too, I hope.

thyroiduk.org/further-readi...

[JAmanda in reply to Anthea55]

I don’t think docs are only worried about osteoporosis as one could just take calcium or d3 k: magnesium etc. I think it’s more than that. My asthma doctor was really keen for me to get my tsh up.

[ERIC107 in reply to JAmanda]

You mentioned that both specialists are nice/friendly... perhaps you could ask WHY they're worried - what, specifically, do they think will happen? If it turns out to be osteoporosis, or something related to asthma, or whatever, then you can give them specific information from the wise folks on here about why they don't need to worry, along the lines of the explanation greygoose gave above.

Edited to add: they, presumably, *think* they are looking out for your best interests but are doing it from a position of misinformation/out-dated information. This is your opportunity to share greater knowledge with them.

[JAmanda in reply to ERIC107]

Well when I said ‘yes my tsh is low but my t3 and t4 are well within range’ he said that the blood tests wouldn’t always show just how how much was in the cells. So there’s another factor.

Being so dreadfully ill with inflammation in my lungs I have to trust them to a degree - my thyroid problems feel like nothing in comparison. There’s so many questions to ask about the lungs I’ve barely time to move onto thyroid… plus folate us now low. I just went down from 25 to 20 lio but I might go further and raise Levo as this doesn’t suppress the tsh so much.

[Mollyfan]

I am pretty sure I am under the same consultant as you, who I found really helpful, understanding and knowledgeable. He said that he would prefer my TSH not to be fully suppressed and suggested I reduce my T4 ( but not my T3) slightly. My TSH was 0.014 and he said he would be happy with 0.02.

I have cut the T4 down from 125 to 100 and actually feel slightly better. Also on 10,5,5 of lio.

They may be worried about this recent study showing the all cause mortality and particularly respiratory risk?

academic.oup.com/jcem/artic....

Good luck!

[Mollyfan in reply to Mollyfan]

Also, these graphs suggest all cause mortality is higher when TSH is below 0.1, but much lower than above 4.

Risks vs TSH

[tattybogle in reply to Mollyfan]

hi Mollyfan , can you remind me which study those graphs are from , i know i've seen them before but can't remember where.

[tattybogle in reply to Mollyfan]

That study ..... ( academic.oup.com/jcem/artic... Association of Thyroid-Stimulating Hormone With All-Cause Mortality: A 2-Sample Mendelian Randomization Study

Yeqing Gu, Zimin Song, Qingkui Li, Jinhan Wang, Yanqi Song, Ge Meng, Hongmei Wu, Shunming Zhang, Xuena Wang, Juanjuan Zhang)

........... the details need more clarification before we know if's findings are applicable to patients taking thyroid hormone replacement.

at first glance i don't think it does apply to us , but it is hard to understand exactly who and what they are looking at

eg :

~ were the ones with the low TSH taking thyroid hormone replacement?

~ is their TSH level being looked at in isolation, or in conjunction with fT4 / fT3 levels ? etc

We know that TSH relationship to fT4 / fT3 level is shifted when patients take thyroid hormone replacement, so any TSH associations from people not taking thyroid hormone do not apply to those who are.

~ is it looking at actual TSH levels ? or at a genetically predicted TSH levels ? (whatever that means in practice )

it says it's a ' Mendelian Randomization Study'

"Methods

MR analyses using single-nucleotide polymorphisms (SNPs) associated with TSH levels (P < 5 × 10−8) as instruments. Mortality data were obtained from the UK Biobank, including 384 344 participants who were recruited from 22 assessment centers across the UK taken between 2006 and 2010. Cox proportional hazards regression was used to estimate the association of the TSH genetic risk score (GRS) with all-cause and cause-specific mortality.

Results

15 557 individuals died during a median of 9.00 years of follow-up in the UK Biobank. A total of 70 SNPs were included in the MR analysis. The main MR analyses showed that 1 SD increase in TSH was associated with a decreased risk of all-cause mortality (OR 0.972, 95% CI 0.948-0.996), which may be largely attributed to respiratory disease mortality (OR 0.881, 95% CI 0.805-0.963). The multivariable hazard ratios (HRs) (95% CI) of all-cause mortality across 3 TSH GRS categories were 1.00 (reference), 0.976 (0.940-1.014), and 0.947 (0.911-0.985), respectively (P for trend < .01). Moreover, except digestive diseases mortality, genetically predicted TSH levels were negatively associated with mortality from CVD, cancer, noncancer diseases causes, and dementia, although not statistically significant. "

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

people with low TSH who are not taking thyroid hormones may have low TSH because they are hyperthyroid, so they have higher risks for all sorts of things ,due to their higher thyroid hormone levels, not the lower TSH.

Patients taking thyroid hormones can have relatively lower TSH without the higher thyroid hormone levels that cause those extra risks .

[tattybogle]

They are scared because the guidelines they follow (and their teaching) currently tells them there is good quality evidence that low TSH has higher risks for "xyz"

But the guideline makers have not taken into account the evidence that TSH has a shifted relationship to fT4 / fT3 levels in patients taking thyroid hormone : healthunlocked.com/thyroidu.... your-pituitarys-opinion-is-a-bit-warped-once-you-take-thyroid-hormone.

... so they assume the risks they find associated to all people with low TSH can be applied to equally to people taking thyroid hormone replacement , but they cannot

healthunlocked.com/thyroidu... useful-evidence-that-tsh-between-0.04-0.4-has-no-increased-risk-to-patients-on-levothyroxine-updated-new-study-does-show-small-risk

[radd]

JAmanda,

‘why are docs so scared by low tsh?’

Old, outdated and incorrect medical guidance still states the TSH should be the gold standard measure for thyroid hormone levels. We know this to be inaccurate for a majority whose TSH-thyroid hormone signal is skewed (for whatever reason) eg has a new & healthy ‘norm’.

The guidance also indicates high levels of thyroid hormone can turn bone over too fast, inducing bone thinning (particularly T3). This is correct EXCEPT we don’t necessarily have high levels of thyroid hormones just because our TSH is low.

So in answer to friendly endo you could ask for the research that states it’s the TSH that dictates bone health (there isn’t any! Even Bianco states TSH has no function when T4 AND T3 are being medicated), and steer him in the direction of the all important thyroid hormone levels (that along with other factors are the bone health dictators).

If your labs were taken as per forum timing protocol, they look good, as FT3 is not too high at 71.4% through range. I myself wouldn’t take it any higher as you have to consider the severity of the additional peaks and troughs.

The research supplied by Mollyfan is not clearly conclusive (as most thyroid hormone research isn’t). There are so many variables and until medicating thyroid hormone replacement is recognised to change the HPT axis, this research can only apply with any degree of certainty to those NOT medicating.

[radd in reply to radd]

JAmanda

Regarding asthma, thyroid hormones (not TSH) influence airway contraction but again different factors are so numerous research often isn’t conclusive regarding the exact influenced mechanisms.

However, Dr Lowe claims in his book The Metabolic Treatment of Fibromyalgia T3 increases the number of beta2-adrenergic receptors in the bronchial tubes which is the exact same influence that a bronchial inhaler performs. He also claims thyroid hormones effect strength of the respiratory muscles, good function of phrenic nerves that regulate diaphragm contractions, and the brains 'central drive for respiration' eg the signalling.

I have a 'PDF Conversion of Dr Lowe’s Thyroid Science Website' but am unsure how to link it to here. However, another interesting angle … .. 'A polymorphism in the thyroid hormone receptor gene is associated with bronchodilator response in asthmatics'.

pubmed.ncbi.nlm.nih.gov/222...

[JAmanda in reply to radd]

I’ve had hypothyroidism for years but suddenly got ill with severe asthma which isn’t being helped by meds at all - so I’ve got to look at all the angles to get better.

[radd in reply to JAmanda]

J,

I too had unknown hypothyroidism (Hashi) for many years before eventually being diagnosed, and was also diagnosed with asthma that an inhaler had no effect on. Hence, I looked further.

Your meds are a good dose and your numbers are good. After being unwell for so many years it takes months/years to reverse all that immense damage. If this were me I would just keep trying to make those thyroid hormone meds work with more efficacy as I was still seeing improvements five years after starting combo meds.

[JAmanda in reply to radd]

Yes I have to remember just how much hip pain and neuropathy I had in my feet for years! I’ve made a little change - it takes a long time for t3 and t4 to change I find - I’ll wait and see.

But now I have to learn everything about eosinophilic asthma which is utterly baffling!

[joydot]

they do tend to panic about the wrong things, dont they?