Change in reference range: Hi, new on here. I... - Thyroid UK

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Change in reference range

Kentishcat profile image
11 Replies

Hi, new on here. I have been hypo for 20 years and have been functioning well, apart from the odd blip, on 100 levo. I usually hover around the 0.2 range of TSH. In December my Docs said I was out of range and reduced dose to 75mg.This, it turns out, was because they have changed the reference range,(range was 0.2-4) not because my levels have changed. (Was still at 0.2) Since then I have become symptomatic. Just had another test and my levels are4.2. The new range is now 0.4 -5.

Does anyone have advice on how to handle this. Or have experienced this reference range change.

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Kentishcat
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helvella profile image
helvellaAdministratorThyroid UK

Am afraid we see this all too often.

Labs do change their reference intervals from time to time. Without knowing the details, it is impossible to identify whether your TSH really had dropped a touch or it was entirely the range being adjusted.

But a tiny bit below on TSH? Firstly, I don't think it justifies any change. But secondly, drop your dose by 25% because you are the tiniest bit below?

If you are driving at 60 but realise you've crept up to 63, all you would do is ease up very, very slightly on the accelerator. You don't make a big change - or you drop quite suddenly to 50, 40, whatever...

Heavy-handed and ridiculous.

And it is yet another reason that doses should not be adjusted by TSH alone.

I suspect if you had FT4 results, there would be next to no difference despite the change in TSH. I mean, you can see changes of more than 0.2 just by time of day the blood draw was done.

StPetes profile image
StPetes

Hi Kentishcat. I believe one of the very well informed members here has an article which people can offer to their GP to persuade them to pay less attention to TSH levels and to focus on symptoms and FT4 and FT3 levels. As far as I remember it's one of Tattybogle's but I may be wrong about that. Maybe Tatty or another member will know what I'm referring to tomorrow.

It's not easy having to argue your case with a GP but it's advisable I think to be firm from the start and not waste time and good health.

You'll find great advice and support on this forum so be brave 😃

tattybogle profile image
tattybogle in reply to StPetes

Yes StPetes ~This one is useful for conversations with GP/Endo as long as TSH is 0.04 or above on Levo , and fT4 is in range (main paper can't be used if TSH is below 0.04 as it does find increased risks below the level , but post does contain some other useful links that can help in that situation) :

healthunlocked.com/thyroidu....

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

This one is useful as long as TSH is over 0.4/ 0.5 ( list of recommendation written for GP's suggesting they keep TSH between 0.4 /0.5 and 2/2.5 in patients on levo):

healthunlocked.com/thyroidu....

  Kentishcat ~ this is the one to use now to show your TSH 4.2 [0.4 -5] on reduced dose of 75mcg is clearly not enough ( that and your symptoms) it will deal very effectively with any suggestion "that you are in range, so it's good enough"

Rather than have the inevitable argument about " but your TSH was 0.02 on 100mccg, so i don't want to prescribe that dose again "... i suggest you show compromise and ask to be given an increase to 87.5mcg to try for a couple of month's to see how that feels .. you may genuinely find that dose is enough anyway ... 12.5mcg is enough to have a significant impact on symptoms ( well it is for me anyway).. and if 87.5mcg still isn't enough once you 've allowed it a couple of months to settle in .. then you have a Much stronger case proving for your need to go back up to 100mcg regardless of whether it takes the TSH a bit under range ( whatever range )

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

*Note ~ 'in theory' a test which uses a different [ref range] will also be giving a different TSH result .. eg. the SAME blood sample 'ought' to come back as:

0.5 [0.5-4]

0.2 [0.2-4]

But you have a strong argument that may not do 'in practice', with your previous stable history of 0.2's .

In reality there are always going to be small differences in the "% through range/ inside range/ out of range" of results when the lab uses a different test platform with a differnt ref range , and the manufacturers/ labs do acknowledge this.

There is plenty of evidence in these posts to show a GP how different test methods (with different ref ranges) are not always very 'equal' in practice: ( these posts relate to differences in fT4 testing methods , but the same issues apply to TSH testing, to a lesser degree.. but i can't find the posts i'm looking for with comparison of two different TSH tests.. i'll add it later if i find it )

healthunlocked.com/thyroidu... free-t4-reference-intervals-ft4-ranges

healthunlocked.com/thyroidu... a-critical-need-for-ft4-test-standardisation

healthunlocked.com/thyroidu... a-long-awaited-letter

*Edit this one relates to differences in TSH testing : healthunlocked.com/thyroidu... what-tsh-test-is-used-affects-diagnosis-of-hypothyroidism

tattybogle profile image
tattybogle in reply to tattybogle

p.s .. in case GP is an idiot who cant work out how to prescribe 87.5mcg because the smallest tablets are 25mcg .....

(apart from some ludicrously expensive 12.5mcg ones that cost £13 a packet made by TEVA , and are therefore unsuitable for many people anyways if they don't do so well on Teva Levo )

... 87.5mcg is usually prescribed as "75mcg / 100mcg alternate days" ..

if you prefer to take the same each day , then just cut a 25mcg in half to get 12.5mcg , and use the other 'half' the next day.

Kentishcat profile image
Kentishcat in reply to tattybogle

Wow, a lot of reading to do 😃 Thank you.

StPetes profile image
StPetes in reply to tattybogle

Thank you!! Your depth of knowledge and experience is impressive Tattybogle.

Kentishcat profile image
Kentishcat in reply to StPetes

Thank you. I will have a look.

Kentishcat profile image
Kentishcat in reply to Kentishcat

Hi all, quick update. I had a phone consult with another GP at the practice (I am new there, so still finding my feet with the docs) After explaining my history to him and what was happening now, he replied that he did not know why my meds were reduced and immediately put me back up to my usual level. Feeling so much better already.

Thanks for all the advice, it gave me the confidence and knowledge to challenge what they had done.😁

tattybogle profile image
tattybogle in reply to Kentishcat

Good :)

Jazzw profile image
Jazzw

If your TSH is now 4.2 then you’re undermedicated now (which isn’t a surprise because you almost certainly weren’t over medicated in the first place). I think I’d be going back to GP to ask for my dose to be restored to 100mcg levothyroxine. You’re symptomatic and your body needs more thyroid hormone.

Batty1 profile image
Batty1

My advice is tell the doctor NO Im not reducing I feel fine and I have been fine with this dose and levels for years…. Its my observation that doctors can only diagnose when labs say their is a problem. I wonder why when you get and ultrasound and it says your having a problem they don’t listen to the Ultrasound….. Crazy

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