Rather shocking publication in my science trail

[Mothebear]

21 million Americans may take a hypothyroidism drug they don't need

by Isabella Backman, Yale University

medicalxpress.com/news/2023...

[ Edited by admin to add the article's title so members can have some idea where the link will take them. ]

[StitchFairy]

I agree, the article is shocking. Personally I think it's scaremongering though. But then I'm in the UK and it's much harder to get prescribed thyroid meds here.

[greygoose]

However, recent research suggests that levothyroxine has no benefit in patients who initiate treatment when their levels are naturally under 7.0 mIU/L.

What rubbish! Many people have terrible symptoms when their TSH is just 2. This is probably all part of a campaign to stop people getting diagnosed, because the medical community hates diagnosing and treating hypo. They just do not understand it. I think the whole article is total garbage.

[helvella Administrator]

Totally agree with StitchFairy

The article is extremely poor.

It says they identify hypothyroidism by TSH followed by FT4. Perhaps they need to look at FT3 as well?

They have this very odd phrase “23 million Americans who are actively taking levothyroxine”. What is “actively taking”? Is there another concept of “inactively taking”?

The primary paper is behind a paywall which means we cannot read it.

We do have access to a letter to the editor: academic.oup.com/clinchem/a...

We have many times here discussed TSH varying through the year.

If the evidence is as claimed, it appears to support the idea that we need to change our doses through the year. (Which is obviously not practical if we are on one TSH test a year as many are.) But those who do change seem to do so by modest amounts – sometimes 25 micrograms between their summer and winter.

This issue has been known and understood since the beginning of thyroid hormone treatment. It is one of the important reasons that pig thyroid was adopted as the standard source for desiccated thyroid. The variation within pigs is much less than in cattle, sheep, etc. Part of that is that pigs are often kept in protected environments - a pig sty right by a house. Rather than ranging across open ground.

How can a new paper point back more than a century? Looks like the variation has simply been ignored by the profession. It is true that much is ignored but this paper tries to claim novelty in their appreciation of the fundamentals which is a gross over-claim.

There are other factors like time of day that TSH is tested. Again, one of the most frequent subjects on this forum.

It is wrong to point at January and February for many reasons. Not least, they are assuming northern hemisphere. And January/February in Tokyo (main paper is from Japan) is massively cooler than, say, Miami. Indeed, Temperatures in Tokyo in May are more similar to Miami in January/February. And they are also assuming that January and February are different in important factors which is likely to be highly geographically dependent.

An annual variation from 4 to 26 (Tokyo) is likely to have a very different impact to 16 to 25 (Miami). Or -11 to 12 (Anchorage) which has no overlap at all with Miami. (Temperatures are the lower end of typical weather in all locations.)

Are they pointing at temperature? Day length? Or some other factor? With heating, cooling, artificial lighting, etc., we need to look at the environmental experiences of the individuals. Not just broad-brush 'pick two months of the year'.

That they are ascribing more than 90% of levothyroxine prescribing to TSH variation seems entirely nonsensical.

Sorry – run out of steam at responding to an article and a response about a paper we can’t access.

[Mothebear in reply to helvella]

Hopefully some competent academic/practitioner will review this article and trounce it using all the points you have so well made.

I’m sure your review and tattybogle’s will be heartening to the Thyroid community here and there!

[FAB-jellybean in reply to helvella]

helvella Primary paper is this one I think (have known to be wrong though so please correct me if I am) and is free to read but you need to sign in to download?

jamanetwork.com/journals/ja...

[Rapunzel in reply to helvella]

Word.

[tattybogle]

But .... this is based on twisted logic , it is over simplistic , and is clearly biased.

they argue that seasonal variation is leading to over diagnosis in the winter months ~ but the samples which make up the ref range are taken at all times of year not just in summer ~ summer readings do NOT make up the 95% population ref range .

If you follow that logic , then the same seasonal variation MUST be leading to an equal amount of UNDER diagnosis in the summer months ~ a point which they conveniently omit to mention.

the same issue also applies to the time of day affecting TSH readings (circadian rhythm) ... research already acknowledges that there are lower diagnosis/ treatment outcomes from TSH blood samples taken in the afternoon .. patients with symptoms may get 'normal /borderline ~ no treatment yet' in the afternoon , but if those same patients had been tested in the morning they may get 'over range/ treatment now'

An un-biased opinion on the effect of seasonal /circadian variation in TSH on rates of diagnosis/ treatment would conclude that the ref ranges need to be redone and separated into am / pm /winter /summer ranges ......and if they were , i strongly suspect that an increase in diagnosis rates from the previously under diagnosed group would cancel out any lower diagnosis from the supposedly over diagnosed group. The numbers treated overall would probably stay pretty similar.

That would be the way to address this issue properly~ not just randomly deciding to increase the top end of the range to 7 ~ based on what ? ~ how many healthy people (of whatever age) have a TSH anywhere near 7 ... virtually 'no one' in any research ve seen .

They suggest a repeat TSH should be done after 3 months to minimise overdiagnosing in winter .. a repeat test before considering treatment of sub clinical hypo is commonly accepted as good practice ~ starting levo for subclinical hypo without a repeat TSH after 2/3 months to confirm the diagnosis is always going to be highly suspect .......... and it is already part of the UK guidelines that a repeat TSH test should be done 3 months after the first in case of subclinical hypothyroidism BEFORE any treatment can be offered by NHS.

if US doctors are really prescribing thyroid hormone to loads of patients after just ONE marginally raised TSH result with fT4 in range , then that certainly does need to be addressed , but i presumed American Doctors /Endo's already have a guideline to cover this requirement , just as we do ?... if they aren't doing a repeat test to confirm before prescribing , they are ill informed idiots that probably shouldn't be prescribing anything to anyone.

[Trina64]

I am in the U.S. and all you need to do is follow the money. It is more profitable for patients to be on several drugs instead of taking one to eliviate symptoms. The pharmaceutical companies want people om antidepressants, heart, blood pressure, pain mess, etc. Who do you think gives LOTS of money to the medical research universities? Pharmaceutical companies!

I actually had a doctor tell me that her pharmaceutical rep loved her because she prescribed so many of the drugs the rep was responsible for showing her.

Doctors are married to test results and the drugs that correspond to that test instead of listening to their patients and getting to the root cause.

If I was in a bad car wreck, then the U.S. is where I want to be for treatment, but doctors fail when it comes to general healtn and i think they don't even know it. I am glad we have the drugs to help people if they really need them, but it has allowed medical professionals to become lazy.

[greygoose in reply to Trina64]

Very well said! Totally agree with you.

[Musicmonkey]

Pfft! Unbelievable

[DippyDame]

Beggars belief....