Re: new test results- help!
Northfortyfarm January 4, 2013
My story is similar to yours. I was on 125 mcg Synthroid (T4) for over 20 years, until problems with SVT, then started doing research on my own. Congratulations on getting all those tests done.
I think your fundamental problem is the same as mine and many others who are only taking T4. The problem is that FT3 will be low relative to FT4 if you only take T4. It is not a problem of your ability to convert T4. This was the research topic for the research paper for which I give the title below. They showed that the FT3 to FT4 ratio is lower in T4 treated patients than in euthyroid people (people with normal thyroid function).
So putting this into ``farmer language`` (no offence intended), if you only take T4, you have to drive up your FT4 to above normal if you want to get your FT3 up to normal. And if you want to get your FT3 higher yet, you have to drive up your FT4 even higher. This is when you start to get into problems, because FT4 gets converted to both FT3 and RT3. If you increase T4 you will increase RT3. RT3 is not neutral - it blocks T3 from working. It can make you feel hypo if RT3 is above normal. So this is why you do not want to go too high on your T4 intake.
A few comments on your labs. If you look at Table 1 of the research paper below, you will see that they give median values for "Euthyroid controls", in other words these are median values for normal people. I think you can use these numbers as a starting point for where to target for your labs.
On Table 1, the median values for females under 60 are:
FT4 13.4 pmol/L
FT3 4.44 pmol/L
Converted to the same units as your labs, the medians are:
FT4 1.04 ng/dL
FT3 2.88 ng/dL
You can see that your FT4 is way higher (+70%) and FT3 is only a bit higher than these levels, but you are not feeling good. Again that is typical of taking T4 only.
So you are now at the point where you learn why a lot of people take both T4 and T3 - because this way you can get your FT3 to optimal level without driving your FT4 to way above normal. And that's what I am doing. Hopefully you have found a doctor who knows how to do this.
Re the cholesterol, I am waiting until my thyroid is optimized. Most docs will tell you to take statins. I did for a long time. I quit because I now believe they can do as much harm as good.
Levothyroxine monotherapy cannot guarantee euthyroidism in all athyreotic patients.
Gullo D, Latina A, Frasca F, Le Moli R, Pellegriti G, Vigneri R.