Help with citations on low TSH with normal T4/T3 on levo/cytomel

[Orangestripeykitten]

Hello. I was hoping someone could help point me to any citations about how T3 suppresses TSH and that this isn't necessarily a problem for asymptomatic people on medication with free T4/T3 in range? I'm getting too many irrelevant search results in NCBI and I only have till Thursday to come up with the right info to educate my Dr with. I am located in the United States but have always found better information here.

TL;DR

Hemithyroidectomy in 2003. Started levo with "borderline high TSH" in 2008.

Current dose: 137mcg levo, 10mcg liothyronine (T3)

Current labs:

TSH (3rd gen ) <0.007 (range 0.358-3.740 uIU/mL)

T4 1.4 (0.7-1.6 ng/dL)

T3 93 (55-172 ng/dL)

Avg resting HR: 63

For the first time in ten years, I feel good. While it took a vegan diet and training for an Ironman, I'm finally keeping my hair and starting to lose some weight without starving (nothing to write home about really, just about 1lb/month but consistent). Please don't lecture me about diet. I have tried them all and this is what has worked for me. I still get more tired than I feel like I should but being 42 year old mother of two with a job, maybe that's just my normal now. When at my worst symptom-wise a few years ago, I was 40lbs overweight, lost my eyebrows, had severe eczema and chronic constipation and was exhausted and freezing all the time - all while my TSH never rose above 2 (I'm sure T4/T3 were low if my doc a the time had bothered to check).

I eventually found a provider who would have been fine with these labs but he changed to a cardiology practice a year ago and I have already changed providers twice since then because nobody listens and I'm running out of options where I live. This new one at least didn't automatically stop my T3 before testing but with these new labs, she wants me to stop all of my meds for a month, which I'm pretty sure will kill me. Why even check T4/T3 if you're just going to ignore the result??? I thought it would at least be worth a try to send some literature to this one in the hopes that she will come around and leave my prescription where it is.

Has anyone had any luck with educating their physician before? I have already been through all of the practices (there are only 2) in my city on the Wentz list. Thank you!

[diogenes Remembering]

There is a very nice resume of TSH suppression by T3 in the site below. It is produced by a patient in Canada who is herself on T3. There are references attached with more information. It's downloadable as:

A Dialogue with Utiger: T3-based thyroid therapy over-suppresses TSH

BY THYROIDPATIENTSCA on SEPTEMBER 10, 2019

Thyroidpatientsca has plenty of very good commentaries.

[Orangestripeykitten in reply to diogenes]

Thanks so much for this. What a fun little rabbit hole that blog is and some great writing and critical thinking. I just finished talking with my doc and I get the impression that the nurse who called me and my doc weren’t exactly on the same page. She just needed to hear that I wasn’t symptomatic and was fine with leaving everything as it is and reassessing in a few months. Woohoo! So once again much ado about nothing. Boy have I been through the emotional ringer over this the past few days though. I guess decades of medical trauma will do that to a person. Boy am I glad I didn’t just give up and go doctor shopping again like I was tempted to.

[Astridnova]

Although it could well be your thyroid, consider also looking into your vitamin b12 levels, which will deplete without supplement on a vegan diet, and cause fatigue and general decline. See for instance, candobetter.net/node/4463

[Orangestripeykitten in reply to Astridnova]

I don't have any symptoms. I just want to stay on my meds. I just had my B12 checked and it's fine. I take a supplement because in one way or another all humans need to since we don't eat much dirt anymore and that's where most of the microbes that typically make B12 come from. Commercial meat animals are also artificially supplemented with B12 since they don't actually make their own either so there's no harm in cutting out the middle-man there.