Would you stay predisposed to certain results?

[misslissa]

Just out of interest say your rt3 was the wrong end of the range can you correct it? Is it a lifestyle thing you have to keep monitoring or is it altered by lifelong meds? 

[radd]

misslissa,

Our genetic susceptibility together with life style choices and medications would all influence the amount of RT3 we have.

As we start investigating the workings of the endocrine system it quickly becomes apparent how immensely complicated it is.

What is known is that elevated RT3 levels can interfere with good thyroid hormone synthesis but these factors that predispose us must effect our ability to reduce RT3 levels too.

[shaws Administrator]

This is another train of thought about RT3:

To answer your question: In a 1994 article, I did write of my testing of fibromyalgia patients for laboratory evidence of elevated reverse-T3. [Lowe, J.C., Eichelberger, J., Manso, G., and Peterson, K.: Improvement in euthyroid fibromyalgia patients treated with T3. J. Myofascial Ther.,1(2):16-29, 1994.] During one year, I tested 50 fibromyalgia patients to see if they had laboratory values that would suggest that they had impaired conversion of T4 to T3 with elevated reverse-T3. I've also tested other patients since 1994. However, I have not found laboratory evidence of impaired T4 to T3 conversion in a single patient.

Also, if impaired conversion was the source of the problem in my fibromyalgia patients, they would respond to a normal physiologic dosage of T3. However, most euthyroid fibromyalgia patients require far more than normal physiologic dosages to overcome their thyroid hormone resistance. 

Finally I decided that if some patients' fibromyalgia symptoms do indeed result from impaired conversion of T4 to T3, it is a rare phenomenon. I could no longer justify charging patients for the laboratory tests that would identify impaired conversion. As a result, I don't even bother ordering the tests any longer. This is the reason that you haven't read about impaired conversion of T4 to T3 and elevated reverse-T3 at this Web site or in more of our published articles. 

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

[jimh111 in reply to shaws]

If only there were a few more physicians of the calibre of John Lowe and Gordon Skinner.  It is so rare to see good science in this area of medicine.

[shaws Administrator in reply to jimh111]

Is there any younger men/women coming forward with their sort of 'basic' knowledge. It would seem the answer is no and the BTA and RCoP stick to the rigidity of levo 'in range' and prescribe according to the TSH. It doesn't make sense to me, unmedically knowledgeable, when they are 'supposed' to be the experts.

There would be no need for forums like this except for support when first diagnosed not for analysing blood tests where the guidelines/dosing falls down.

[misslissa in reply to shaws]

Very interesting. Probably a silly question but did your fibromyalgia sample actually have hypothyroidism too?? I'm assuming they did. If this is the case are you basically saying it's rare for people to have an issue converting t4 to t3? 

[shaws Administrator in reply to misslissa]

I don't think it's rare and this is a link which might be helpful in understanding.

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

Dr L was Director of the Fibromyalgia Research Foundation. He died due to an accident.

[misslissa in reply to shaws]

I was hoping you'd say yes it's rare as every forum I'm on seems to raise it as a huge issue and tbh it can make me feel like I'm destined for ill health. It's very negative. Until I get a full thyroid panel done I won't really know what's going on. 

I'll have a read now. I used to have CFS and many of my fellow group members had fibro so it's an interesting link for me. 

[shaws Administrator in reply to misslissa]

This is another interesting one from the same Dr Lowe:

web.archive.org/web/2010081...

[jimh111]

There are rare conditions associated with elevated rT3, but in general rT3 will be high if your thyroid hormone levels are high, in particular fT4.  i.e. if you are taking large doses (125 - 150 mcg ?) of levothyroxine.

Although elevated rT3 can block the action of T4 nobody knows how to quantify the effect.  Given this information my own view is that it is a waste of money doing rT3 assays, they don't tell you anything new and you can't calculate the effects the rT3 might be having.

My simple approach is to make sure your fT4 does not go above the upper limit of the reference interval.  If you still have clear signs and symptoms of hypothyroidism switch to T3 containing medication but ensure you do not develop signs of too much hormone such as a slight hand tremor or increased heart rate.

[misslissa in reply to jimh111]

I think that makes sense, do you mean people on high doses of thyroxine are the ones that might struggle to convert?

[faith63 in reply to misslissa]

even at low doses of t4, my rt3 was on the high side. ..i simply did not convert well and could not utilize t4.  

[misslissa]

I wasn't just thinking about rt3 but t3, adrenals too. Fortunately I've just had my adrenals checked privately and they've come back really good. So am I likely to stay that way or would I need to recheck routinely? 

Maybe that's what I'm thinking, I know GP's will keep a check in my TSH and t4 but not rt3, t3, adrenals, ferritin, b12 etc. So say my b12 is low, but I get treatment, would that fix it or is again a lifelong thing to keep checking? My ferritin was 33 last year and after 3 months of 3 X a day treatment it's now 74, is it likely to deplete again unless I keep supplementing and retest regularly? I mentioned my Vit d the other day and it's good but I was advised to supplement to keep it up. So will this be the case with all these other things?! 

I guess I'm trying to get a feel of what I need to be routinely checking and/or supplementing. 

[jimh111]

If your fT4 goes high (or fT3 possibly, the research isn't conclusive) your rate of 'type 1 deiodinase' (D1) will increase.  D1 converts T4 to equal quantities of T3 and rT3.  Another deiodinase called D2 converts T4 to T3 and this seems to be upregulated by TSH (i.e. when fT3 or fT4 are low).  So these two deiodinases play a regulatory role, especially within certain cells such as in the heart and brain.  So if you take high doses of levothyroxine (L-T4) your D1 will go up and so will your rT3.  (It is thought this D1 mechanism is partially to mitigate thyrotoxicosis and partly to facililtate iodine conservation at the smaller T3, rT3 molecules are more easily reabsorbed into the gut (which they enter via the bile from the liver).

In the case of John Lowe's patients who require supra-physiological doses of hormone (probably due to some form of peripheral hormone resistance or endocrine disruption) if they were given L-T4 the above deiodinase mechanisms would counteract the benefit of the L-T4 as more rT3 would be produced.  By giving his patients L-T3 (liothyronine) Lowe was able to bypass the normal diodinase mechanisms and thus deliver high levels of fT3 to his patients.

I'm not into lots of vitamin tests.  Ferritin is important and you may find it gets better as your thyroid problem is sorted.  If B12 is low then you will probably have to continue to supplement.  Vit D is really important, as well as bone effects it helps protect against cancer.  The best form of vit D is prudent exposure to sun.  I will get as much gentle sunshine as I can during the sunnier months and supplement with vitamin D3 during the winter.  The best forms of vitamins are a healthy diet and prudent exposure to the sun.

[humanbean]

Back in 2013 I had high levels of reverse T3 (way over the range). I got it back into the upper half of the reference range by taking T3 only in quite high doses for a couple of months.

Since reducing my reverse T3 I've never felt I needed high doses of T3 again.