Help with test results please: T3 only, why is TSH not higher if FT3 and FT4 below range?

[cazzaleo]

Hi all

I’ve been on T3 only for about 6 months now, started off on 5mcg/day, then 10mcg/day, went onto 15mcg/day about 6-8 weeks ago. At my last appt the ending said he wasn’t keen on going to a higher dose but I feel like I need it and my bloods from last week seem to indicate I do too - here are my bloods from Dec 17 to last week:

15/12/17

TSH 1.23 (0.35 - 4.5)

Free T3 3.4 (3.9 - 6.8)

Free T4 15.2 (11 - 26)

24/2/18

TSH 1.65 (0.35 - 4.5)

Free T3 3.1 (3.9 - 6.8)

Free T4 15 (11 - 26)

8/5/18 (10mcg T3 only/day)

TSH 2.33 (0.35 - 4.5)

Free T3 4.3 (3.9 - 6.8)

Free T4 12.4 (11 - 26)

2/8/18 (15mcg T3 only/day)

TSH 1.55 (0.35 - 4.5)

Free T3 3.7 (3.9 - 6.8)

Free T4 8.2 (11 - 26)

So my TSH, FT3 and FT4 have all dropped since my last increase, even though I feel a little bit better??

Should my TSH not be higher as my body should be trying to increase my below range FT3 and FT4? Does this mean there’s an issue with my feedback loop/pituitary?

Any advice very gratefully received! I should be seeing the endo again shortly and want to be well informed about what these results mean and to have an argument to back up my request to increase the T3!

Many thanks!

[SlowDragon Administrator]

TSH is pretty much always suppressed when on T3

If you are only taking T3 and nothing else you are on very low dose

Most patients would be on Levo and small addition of 15mcg T3

You probably need to increase dose

Why are you not taking Levothyroxine as well?

[cazzaleo in reply to SlowDragon]

Thanks SlowDragon. Endo said there wasn’t a problem with my FT4 or TSH when I first saw him and that I wasn’t strictly hypothyroid but he was prepared to give me a trial of T3 to see if it helped anyway. Do you think I should’ve been on Levo as well from the start then?

[shaws Administrator]

I agree with SlowDragon that your T3 dose is too low. I suppose Endo is fixated with the TSH which will be low on T3 only. 25mcg of T3 is equal approx - in its effect to 100mcg of levo so your dose isn't sufficient. The action of T3 is to saturate all of our T3 receptor cells - we have millions - and it is the only Active thyroid hormone needed in our millions of T3 receptor cells. This enables our metabolism to work normally when we are on a dose which permits this.

Also the blood tests were introduced along with levothyroxine, so if we add in T3 or take T3 alone then the blood tests cannot correlate and it should all be about 'how the person feels on their dose of hormones'. One of our advisers increased by patient's dose by 1/4 tablet every two weeks until the patient was symptom-free. The patient also took their temp/pulse several times a day when introducing increases and if either went high they reduced to previous dose and that seemed to be their optimum.

I take T3 only and have a yearly blood test now.

[cazzaleo in reply to shaws]

Thanks shaws. The endo told me I was on quite a high dose already! I knew that wasn’t the case from what I’ve seen on here, but maybe he was talking specifically about dosing in what he considers to be an unconventional case I.e. because he says I’m not really hypo?

Either way, it seems to me from the results (and what you guys in the know are telling me!) and how I feel that I need a higher dose. Fingers crossed I can convince him!

Otherwise I suppose I can buy some without prescription to top up!

[shaws Administrator in reply to cazzaleo]

Tell him also that some people have Thyroid Hormone Resistance in that they need larger doses than 'ordinary' people and greygoose knows more than most doctors/endos. This is some info:-

web.archive.org/web/2010103...

[cazzaleo in reply to shaws]

Thanks shaws!

[greygoose]

I would suggest that you suggest to your endo that the reason your TSH was never 'a problem' was that you have a pituitary problem - Central Hypo, when the Frees are low, but so is the TSH because the pituitary can't produce enough - for one reason or another. I doubt he knows enough about thyroid to have thought of it for himself, but he could go away and google it. And, your FT4 was low enough to warrant a little levo.

[cazzaleo in reply to greygoose]

Thanks greygoose!! He did test some other hormones back in Feb, would any of this be used to try to diagnose a pituitary problem?:

FSH 4 iu/L (1-11)

LH 2.5 iu/L (1-12)

Prolactin 451 mu/L (102-496)

[Angel_of_the_North in reply to cazzaleo]

He tested those to see if he could blame your problems on menopause. Your prolactin is near top of range and high prolactin is often indicative of a pituitary problem.

[cazzaleo in reply to Angel_of_the_North]

Thanks Angel of the North! Thinking about it he did mention about checking for menopause but I wondered if these might also give any other clues.

What testing is required to determine if there’s a pituitary problem?

I’ve had a couple of bashes to my head over the last 15 years and do wonder if I could have damaged it that way.

[Angel_of_the_North in reply to cazzaleo]

I'm not sure what tests they do these days. Many years ago I had a short synacthen test, an insulin stress test and a CT scan

[cazzaleo in reply to Angel_of_the_North]

Thanks. I had a short synacthen test back around Feb/March too, apparently didn’t show anything out of the ordinary. I’ll look into those other ones. Thanks for your help.

[greygoose in reply to cazzaleo]

pituitary.org.uk/informatio...

This will tell you about the tests necessary for the pituitary. And this :

endocrinologyadvisor.com/en...

will tell you about Central Hypo.

[cazzaleo in reply to greygoose]

Fantastic, thanks greygoose!

[greygoose in reply to cazzaleo]

You're welcome.