Low TSH and increased AD risk, with normal T3 and T4

[karelena]

https://www.hindawi.com/journals/isrn/2013/856017/

From the article:
There are a number of possible explanations for the finding of lowered TSH in AD. A decrease of the thyrotrophic-releasing hormone (TRH) can enhance the phosphorylation of tau-protein and other proteins that are potentially involved in the pathogenesis of AD [24]. TRH increases the acetylcholine synthesis and release in rats, indicating that reduction of TRH may cause acetylcholine decrease, an important factor in the development of AD.


I had not heard this before, and Bredeson's target for TSH is "< 2.0 microIU/ml," he does not state a level that is too low. I started taking synthroid years ago due to lower than "optimal" free T4 level. My TSH is now very low, 0.1. I did not know this was a problem because the T4 and T3 levels are in the targeted range. But apparently we need to have some TSH (and TRH) around.

I have my Bredeson trained doctor to thank for pointing this out to me. Our plan is to lower the synthroid dose until TSH rises, and then try to slowly wean off the synthroid as long as T3 and T4 are still in range.

[slacker]

This meta analysis of subclinical hyperthyroidism (SH) shows an association between low TSH and AD even with normal T3 and T4. Associations do not prove causal relationships, but they do peak our interest. Each study appears to have a different patient population and different normal ranges of TSH; some used total T3 and T4, others used free T3 and T4. A quick review of the meta analysis leads me to believe that if we are on thyroid hormone replacement, we should keep our TSH above .4 or .5 to be "safe". Balancing out too low and too high.

I am rechecking my levels next week!

Any other thoughts?