Free T3 vs Reverse T3...sigh

[soupybp]

Reminder that I am in the US. Asked GP for an order for a good thyroid workup on hubby because of all of his health issues (and requested same for me since I have not had one and am suspicious based on symptoms). I provided the full list of tests and nutrient tests. He was cool with all of it except the Free T3!

He replied:

"I didn't order the Free T3. It is not a super useful test especially since we already have the reverse T3 ordered."

I just want to see if I am missing something here. Thoughts? Anyone have a good link I can send him that explains?

[greygoose]

No, it's him that's missing something - a decent thyroid education. An FT3 test is far more useful than an rT3 test - cheaper, too. But, he obviously doesn't understand T3.

[soupybp in reply to greygoose]

Thanks. I appreciate the affirmation.

I think that since hubby hasn't had anything beyond TSH/fT4 tested in the past (and those not recently), that he has liver fibrosis, AND we have met our medical out of pocket maximum for the year, I think that it is prudent to get the rT3 done at the same time as everything else so that it is a really good full picture.

I am hopeful that gp is willing to be educated - I am disappointed and frustrated with his response.

[greygoose in reply to soupybp]

You can get it tested if it's on offer, but it really won't give you any useful information. It's one of those tests that tell you if there's a problem but doesn't tell you what it is. Contrary to what some doctors think, it doesn't tell you if you're converting well because there are so many things that can cause a high rT3. And, as far as we know, the rT3 itself doesn't cause problems, because it's inert. And, it only stays in the blood for a couple of hours, and is then converted to T2.

The best way to tell how well you're converting is to compare the FT4 with the FT3. But, even then, you won't know why you're not converting well. It could be due to low nutrients, high cortisol, low calorie intake, etc. etc. etc. But, I'd be interested to know what the endo makes of the rT3 results.

[guysgrams]

It's unfortunate but the doctors here in the US don't seem to think there is any relevance. I had the same conversation or heated discussion I should say with my PCP regarding a FT3 test. Got absolutely no where with her. She ended up referring me to an Endo who was some what helpful but am changing again.

[soupybp]

So after I "calmed down" a bit, I replied to the gp that I was really surprised by his response - I was hoping that maybe he just got the two items mixed up in a moment of distraction. I told him that there is differing opinion regarding the usefulness of rT3, so I wouldn't be surprised if he questioned that test. But that fT3 is one of the key thyroid tests because it is actually testing what the body can use in the cells and is highly underutilized by the medical community at large.

His reply was a lab order for fT3 with no other commentary...for whatever that is worth.