Low-normal thyroid and health implications - new article in Nutrients Journal (peer reviewed)

I've just come across the following article which appeared in the Nutrients Journal (Netherlands) on 16 Feb:


Here is the abstract:

'The concept is emerging that low-normal thyroid function, i.e., either higher

thyroid-stimulating hormone or lower free thyroxine levels within the euthyroid reference

range, could contribute to the development of atherosclerotic cardiovascular disease. It is

possible that adverse effects of low-normal thyroid function on cardiovascular outcome may

be particularly relevant for specific populations, such as younger people and subjects with

high cardiovascular risk. Low-normal thyroid function probably relates to modest increases

in plasma total cholesterol, low density lipoprotein cholesterol, triglycerides and insulin

resistance, but effects on high density lipoprotein (HDL) cholesterol and non-alcoholic fatty

liver disease are inconsistent. Low-normal thyroid function may enhance plasma cholesteryl

ester transfer, and contribute to an impaired ability of HDL to inhibit oxidative modification

of LDL, reflecting pro-atherogenic alterations in lipoprotein metabolism and HDL function,

respectively. Low-normal thyroid function also confers lower levels of bilirubin, a strong

natural anti-oxidant. Remarkably, all these effects of low-normal thyroid functional status

appear to be more outspoken in the context of chronic hyperglycemia and/or insulin

resistance. Collectively, these data support the concept that low-normal thyroid function may

adversely affect several processes which conceivably contribute to the pathogenesis of

atherosclerotic cardiovascular disease, beyond effects on conventional lipoprotein measures.'

The wording is somewhat circumpect ('could contribute'; 'may be ... relevant'; 'Probably relates to', etc., but there are some interesting concepts here.

Is there anyone with the knowledge/expertise who could decipher it for us mere mortals? And also state if it is a document we could present to GPs/endos? In other words, is there enough scientific evidence, given the hesitant stance of the abstract?

NB the 'About us' page of the Journal's website opens with the following sentence: 'Nutrients (ISSN 2072-6643) is an international, peer-reviewed open access advanced forum for studies related to Human Nutrition' , so it has 'proper' status, as it were.

11 Replies

  • If we, who are medically untrained, can suss out that it is wrong not to include Free T3 in our blood tests, why is it taking so long for those who are supposed to be medically trained cannot fathom this out. Why is it so difficult? It's common sense and you don't need a degree surely. The doctors are quick to prescribe statins for a higher cholesterol and don't take notice of low thyroid hormones at all.

    Holistic doctors have been saying for ages that low thyroid function causes all these additional problems yet the mainstream ignore and our symptoms are treated as 'stand alone' and the need for an increase and/or the addition of T3 as levo doesn't always convert sufficiently.

    I hope some knowledgeable persons will comment.

    Thanks for the link.

  • Hi Shaws, many thanks for your response. I have to say I'm disappointed that there weren't any other replies as I thought this might generate a lot of interest, esp from those, like me, who have low-normal thyroids and are therefore not getting anywhere with the GP or endo. Perhaps I should re-post? I was hoping those with greater medical knowledge would give their twopenneth.

    Also, I was thinking of contacting one of the authors to ask for clarification about their definition of low-normal. As far as I can see, this isn't overtly defined.

  • Sometimes a particular post doesn't get too many responses and some don't have any, probably because none is required. Sometimes they're a bit over the head of some who suffer with 'brain fog' and it can be difficult to remember or absorb info.

    Also, before the change-over to posts only which now consists mainly of questions, there were two places to put info, i.e. Posts or Questions. Now that they're lumped together posts/questions are now mixed together and things get pushed off the front page very quickly and unless you search for a particular 'item' they might never see the light of day again.

  • Hi Ann, thanks for your link.

    I've posted several links to papers and books which comment on cardiovascular illness etc that are a result of low or low-ish thyroid.

    Here's another post of mine..


  • Many thanks - I'll have a look at your postings. Re: the conference subject, tests show I don't have any pituitary problems. It's a bit of a mystery as both FT4 and FT3 are low-normal but TSH is well within range (well, not according to the forum)! WIll be posting latest results shortly for people's consideration.

  • Apparently, low or low-ish TSH, FT4 and FT3 is secondary hypothyroidism.

  • In my case TSH is 2.53 (0.35-6.00) as of results collected yesterday (3.36 in May 2014), but the latest FT4 (July 2014) is 13.6 (9-22) so just above the lowest quartile, and FT3 is 3.14 (2.63-5.7), therefore within the lowest quartile. Of course, Ft4 and FT3 may have altered since they were last taken.

  • Hi Ann, my lab results are all, I think, lower than yours.

  • There is a basic logic in this paper, which hardly requires research, but given that so many studies confirm the bl**ding obvious.....

    Raised TSH is known to cause blood cholesterol to rise, This is likely due to the fact that cholesterol is a precursor to T4 and T3, which cannot be made without it, so a ready supply is a good idea in this situation. So raised cholesterol is an indicator of hypothyroidism, regardless of whether TSH is 'normal' ( that term just makes me furious nowadays!!). It is NOT an isolated symptom to be zapped by statins.

    Now if indeed raised serum cholesterol causes heart disease then so-called low-normal T4, or for that matter high-normal TSH will lead to heart disease. SO WHY CALL IT NORMAL, YOU DIMWITS? (shouting at the medical establishment here, not you readers of HU!)

    And why not do a trial getting patient levels optimal, or go for, at least, high normal T4 ?

    I just get bso very frustrated!

  • Ruthi, which "paper" are you referring to? And what's bso? :(

  • Londinium I have no idea where the original information came from, but I have read it in several different places - enough for it to lodge in this foggy brain.

    Here's one article referring to studies.


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