FT3/rT3

[olga67]

Hi everyone,

I have posted mine lab results 8 days ago without FT3 and RT3.

Today I have received FT3 and RT3 results from the lab. All tests done at once at 8.30 in the morning on the empty stomach, more than 24 hours after last dose of Levo. Could someone, please, have a look?

FT3 4,11 pml/l 3.08-6.78

RT3 255.5 pml/l 138-331

TSH 2,87 mu/l 0.27-4.20

FT4 14.03 pmol/l 11.60-21.90

TT3 1.71 nmol/l 1.23-3.08

I am on 50mcg Levo. How about T4/T3 or rt3 conversion?

[SeasideSusie Remembering]

All tests done at once at 8.30 in the morning on the empty stomach, more than 24 hours after last dose of Levo

How much more than 24 hours? 24 hours is the correct time gap, any longer and you get a false low FT4.

TSH 2,87 mu/l 0.27-4.20

FT4 14.03 pmol/l 11.60-21.90

FT3 4,11 pml/l 3.08-6.78

These are the results that count. You are currently undermedicated. When on Levo only, the aim of a treated hypo patient generally is for TSH to be 1 or lower with FT4 and FT3 in the upper part of their ranges if that is where you feel well. Your TSH is too high, your FT4 is only 24% through range, your FT3 is 28% through range, they are balanced. Normally we can only tell is T4 is converting well enough to T3 when TSH is down to around 1, but at the moment you don't have a problem there.

TT3 1.71 nmol/l 1.23-3.08

Total T3 doesn't tell us anything, it's the Free T3 that tells us what we need to know - the amount of T3 that is available to the cells.

RT3 255.5 pml/l 138-331

As for reverse T3, that is within range but even if it was high the test can't tell you what caused it to be high and there are many, many reasons for high reverse T3 that aren't connected to the thyroid at all so it really isn't a test that's worth spending money on.

[olga67 in reply to SeasideSusie]

Thank you, SeasideSusie for very useful info. The time gap was about 27-28 hours. I wake up very early, around 4a.m. (can’t stay in bed longer) and take mine Levo straight away. I have an appointment with Endo in the middle of June, gonna ask for Levo increase. Mine GP is useless. I have been also scheduled for thyroid US. How useful is that for Hashimoto patients?

[SeasideSusie Remembering in reply to olga67]

I have been also scheduled for thyroid US. How useful is that for Hashimoto patients?

I'm afraid I'm not that clued up about ultrsounds, I don't have Hashi's. I think it shows if you have nodules and probably gives other information as well, but I wouldn't like to guess, sorry.

[olga67 in reply to SeasideSusie]

Thanks anyway

[SlowDragon Administrator in reply to olga67]

Yes ultrasound should show extent of damage to thyroid

Can appear granular rather than smooth. Often with nodules

[olga67 in reply to SlowDragon]

Thank you

[shaws Administrator]

There's no need to worry about RT3 as that what happens when we take levothyroxine i.e. T4 and some is converted to RT3 before T3. Explanation below. You need an increase in dose as TSH is too high - the aim is 1 or below. Both Frees could be higher.

This is from Dr. Lowe:

"Dr. Lowe: Some readers will not be familiar with reverse-T3, and I know from experience that many others harbor misconceptions about the molecule. Because of this, I have summarized in the box below what we know about reverse-T3. I've answered your question below the summary.

Conversion of T4 to T3 and Reverse-T3: A Summary

The thyroid gland secretes mostly T4 and very little T3. Most of the T3 that drives cell metabolism is produced by action of the enzyme named 5'-deiodinase, which converts T4 to T3. (We pronounce the "5'-" as "five-prime.")

Without this conversion of T4 to T3, cells have too little T3 to maintain normal metabolism; metabolism then slows down. T3, therefore, is the metabolically active thyroid hormone. For the most part, T4 is metabolically inactive. T4 "drives" metabolism only after the deiodinase enzyme converts it to T3.

Another enzyme called 5-deiodinase continually converts some T4 to reverse-T3. Reverse-T3 does not stimulate metabolism. It is produced as a way to help clear some T4 from the body.

Under normal conditions, cells continually convert about 40% of T4 to T3. They convert about 60% of T4 to reverse-T3. Hour-by-hour, conversion of T4 continues with slight shifts in the percentage of T4 converted to T3 and reverse-T3. Under normal conditions, the body eliminates reverse-T3 rapidly. Other enzymes quickly convert reverse-T3 to T2 and T2 to T1, and the body eliminates these molecules within roughly 24-hours. (The process of deiodination in the body is a bit more complicated than I can explain in this short summary.) The point is that the process of deiodination is dynamic and constantly changing, depending on the body's needs."

[olga67 in reply to shaws]

Thank you, Shaws.

[SlowDragon Administrator]

Ask GP or endocrinologist to test vitamin D, folate, ferritin and B12

These are frequently too low when under medicated or with Hashimoto's

Are you on strictly gluten free diet? If not continue eating high levels gluten and get endocrinologist to do coeliac blood test

Hashimoto's affects the gut and leads to low stomach acid and then low vitamin levels

Low vitamin levels affect Thyroid hormone working

Poor gut function can lead leaky gut (literally holes in gut wall) this can cause food intolerances. Most common by far is gluten. Dairy is second most common.

According to Izabella Wentz the Thyroid Pharmacist approx 5% with Hashimoto's are coeliac, but over 80% find gluten free diet helps, sometimes significantly. Either due to direct gluten intolerance (no test available) or due to leaky gut and gluten causing molecular mimicry (see Amy Myers link)

Changing to a strictly gluten free diet may help reduce symptoms, help gut heal and slowly lower TPO antibodies

Ideally ask GP for coeliac blood test first or buy test online for under £20, just to rule it out first

Assuming test is negative you can immediately go on strictly gluten free diet




(If test is positive you will need to remain on high gluten diet until endoscopy, maximum 6 weeks wait officially)




Trying gluten free diet for 3-6 months. If no noticeable improvement then reintroduce gluten and see if symptoms get worse

chriskresser.com/the-gluten...

amymyersmd.com/2018/04/3-re...

thyroidpharmacist.com/artic...

scdlifestyle.com/2014/08/th...

drknews.com/changing-your-d...

restartmed.com/hashimotos-g...

[olga67]

Thanks, SlowDragon for the extensieve explanation