TSH variability

[diogenes]

This new paper (open) describes how variable is TSH in individuals and discusses the implication on using this for diagnosis.

REVIEW ARTICLE

Front. Endocrinol., 24 February 2021

doi.org/10.3389/fendo.2021....

Within-Person Variation in Serum Thyrotropin Concentrations: Main Sources, Potential Underlying Biological Mechanisms, and Clinical Implications

Evie van der Spoel , Ferdinand Roelfsema and Diana van Heemst

[diogenes Remembering]

Suppressed TSH isn't involved here, I think because it is still a controversial area.

[TaraJR]

As Hidden queried, this is an interesting paper on a quick first read. But where do we stand with suppressed TSH?Very many of us have suppressed TSH when we take T3, and at every appointment we have a battle with our doctors to keep the right dose for us as 'TSH is the gold standard', despite our T4 and T3 not being over range.

Some are best when taking T4 and their TSH is suppressed.

We need a pack of research papers helping us on this!

[Hoxo in reply to TaraJR]

This article again by Tania Smith thyroid patients Canada explains how antibodies can suppress TSH. Quite complex but still very useful. thyroidpatients.ca/2019/07/...

[diogenes Remembering in reply to TaraJR]

The really interesting thing to look at is the spikiness of TSH values over the day, moment-by-moment. This spikiness destroys the use of TSH as a diagnostic by itself. It is quite possible to take a blood sample at a TSH peak and get a totally different indication from one taken a minute or so before or after. This is the message it gives to me - that a socalled subclinical hypothyroid diagnosis might be made when this was just a fleeting episode. TSH is under a cloud just from this observation. Never mind the other additional problems the paper throws up.

[helvella Administrator in reply to diogenes]

Is all the measured TSH the same?

There is some questioning as to whether the TSH isoforms change as we age so that the higher TSH observed in older people is a function of producing more inactive TSH rather than a higher "real" TSH level.

ncbi.nlm.nih.gov/pmc/articl...

Or has that line of investigation not been useful?

And do we still have assays susceptible to macro-TSH?

[diogenes Remembering in reply to helvella]

I think the potential problems haven't really been resolved, so a lot of these possible problems remain just that. Heterophilic antibodies are still a continuing headache as significant interferences.