DI02 gene. T3 only or T4 and T3?

[Sally56]

Hi, I have been trialing T3 only for 4 months now after discovering I was Homogenous for DI02 and hetereogenous for DI01 genes. I am also having B12 injections. I was wondering if anyone else, especially with the DI02 gene polymorphism, take T4 as well or is it better to take T3 only? Thanks. I am still struggling and would appreciate any advice.

[Lalatoot]

It is very much an individual thing. Some manage well on t3 only. Others need the combo. On a combo many need ft4 and Ft3 well over half way through their ranges but some are well with ft4 low in range as long as Ft3 is high. It is trial and error.

[Sally56 in reply to Lalatoot]

Thank you Lalatoot, I have been trial and erroring for a few years now. T3 only is my last resort. FT4 didn't help, but T3 is so hard. I tried NDT and combo T4/T3 as well. But thank you.

[shaws Administrator]

Your dose of T3 may not be high enough to relieve your symptoms.

This is an extract from TUK:

"To explain this paper briefly, the DIO2 gene activates tri-iodothyronine (T3) and the researchers found that a tiny fault in this gene could mean that although the body gets enough T3, the brain doesn’t.

The researchers found that patients on levothyroxine (T4) alone felt worse if the faulty DIO2 gene was inherited through one parent and worse still if they inherited the faulty gene from both parents.

The patients on this study were given T4 only for a set period and then combination treatment of both T4 and T3. The patients who had normal genes did not feel any different on combination treatment. However, those who had one faulty gene felt better on the combination treatment and those with both faulty genes felt better still.

This means that there is a possibility that patients who are on levothyroxine alone and still have symptoms may improve with the addition of T3.

Because this faulty gene causes a deficiency of T3 within the cells, the usual thyroid hormone function tests will not show up a problem. This means that your TSH, FT4 and FT3 blood tests will look normal.

The study concluded,

“Our results require replication but suggest that commonly inherited variation in the DIO2 gene is associated both with impaired baseline psychological well-being on T4 and enhanced response to combination T4/T3 therapy, but did not affect serum thyroid hormone levels.”

Because this faulty gene causes a deficiency of T3 within the cells, the usual thyroid hormone function tests will not show up a problem. This means that your TSH, FT4 and FT3 blood tests will look normal.

thyroiduk.org.uk/tuk/testin...

[Sally56 in reply to shaws]

Thanks Shaws, That is very informative. My brain is definitely better on T3. it's my weakness and pain that hasn't altered.

[shaws Administrator in reply to Sally56]

Maybe you need NDT? Of course, it isn't prescribed in the UK any longer. Unfortunately.

[Sally56 in reply to shaws]

HI Shaws, I did trial NDT, but that didn't work for me either. However, when I get my B12 sorted out maybe I could try that again? Thanks.

[SlowDragon Administrator]

How much T3 are you taking?

Single dose or split dose?

Are your vitamin levels optimal

Do you have hashimoto’s?

I am heterozygous DiO2, hashimoto’s, gluten intolerant and vitamin deficient if not continuously supplementing. I have found I only need small dose of T3 alongside levothyroxine.

125mcg levothyroxine plus 20mcg T3 (as split dose 10mcg at 7am, 5mcg at 3pm and 5mcg at 11pm) - equal 8 hours gap between doses

Not had Dio1 tested

[Sally56]

Hi Slow Dragon,

I am taking 50mcgs T3 only now. 6.30am ish 25mcgs, 12.30 15mcgs and 6.30pm 10mcgs. I have done this over a 3month period whilst cutting out T4 altogether.

I have had a total thyroidectomy.

My vitamins are optimal on paper, but I am having B12 injections every second day because of neurological damage and this may be skewing things as well. I supplement B12, Folic, Vit c, selenium, zinc, iron, Vit D, magnesium. I have had low iron and Vit D in the past.

So you still take T4 as well. I have tried this but have not been able to get my T3 up as high as one dose of 5mcgs, I think because of B12. (not sure)Thanks.

[shaws Administrator]

Maybe the following link will be helpful.

thyroiduk.org/tuk/testing/D...

This is another link by a scientist/doctor whose speciality was metabolism and an expert in the use of T3. He would prescribe NDT (never levo) or T3 for patients who had thyroid hormone resistance. It is a step-by-step routine.

nebula.wsimg.com/b822d36efe...

Dr Lowe (the second link) was also an Adviser to TUK before his accidental death.

He would never prescribe levothyroxine: only NDT or T3 for patients who had Thyroid Hormone Resistance.

[Sally56 in reply to shaws]

Thanks Shaws, I have been keeping a diary for the B12 symptoms but I guess they intermingle with the thyroid ones. Was the Doctor a proponent of T3 only therapy? Today I am going to increase my dose to 55mcgs. I will feel yuk for a while I know. I just feel edgy and anxious on it. If I don't get some relief, I shall try NDT again I think.

I'm just confused about what my options are with being homogenous to the Di02 gene?