latest TSH and T4 since switch to NDT

[sue_b]

Whoops, my new GP wanted to test my thyroid and of course i said yes. Had to tell him I was taking ndt after he told me my results: 

TSH: 0.027   range 0.350 - 4.94

FT4: 10.5     range 9-19

I actually feel quite energetic in my mind and perhaps physically too, maybe slight pressure of speech. Actually I feel better than I have in a long while but then some other pressures have lifted and maybe I am processing the ndt more effecively as a result. Another factor that may be influencing things is I recently developed DVT and Pulmonary embolisms so am on Xarelto which may be impacting how my body is functioning.  Have no signs of being hyper, pulse is in the 60's . I have been taking 4 NDT, thinking I should drop to 3. 

Any views on those results?

thank you

[sue_b]

Should add that i was on 125mcg levothyroxine with tsh of 2.23 before switching to NDT, with cholesterol at 5.9. 

Cholesterol is now 4.4. 

Being a fan of a certain Dr who writes about cholesterol resarch, I am now wondering whether this lowered cholesterol actually contributed to my DVT. I know I am being speculative but  .... think I might skip the NDT today and reduce dose. 

[Jazzw]

The trouble is, those results tell you precisely nothing about whether you're on the right dose or not. FT4 is often lower than expected when you take NDT. And TSH is often suppressed on NDT. So, so far, nothing to support a decision to reduce your dose. You need an FT3 result - but by far the best gauge of whether you're on the right dose is how you feel! So 4 grains might well be right for you. Dropping a grain is perhaps a bit drastic.

And cholesterol is raised in undertreated hypothyroidism, so if it's come down, I think that's a good sign in this case. I too enjoy a good read of Dr Malcolm so I get where you're coming from, but I think deciding low cholesterol causes PEs might be a jump too far.  Did you know that PEs can be a sign of low B12? How's your B12 looking?

[sue_b in reply to Jazzw]

Thanks jazzw

interesting comments. I have got a urine test to do for t4 and t3 privately which will tell me about the t3, will have to wait a couple  of weeks though, about to go away. 

I had a little look on line about my level of tsh and most of the hits were from people who were thyroid cancer patients being maintained on low tsh to help with recovery?   

Regarding the cholesterol, yes, I know, I am stretching a bit, wondered what others thought so thanks for your input  

Sue

[Jazzw in reply to sue_b]

You'll find lots of people right here on this forum taking NDT with suppressed TSH who haven't previously been diagnosed with thyroid cancer. Our GPs tend to not understand that it's fine if FT3 isn't over range (and sometimes, even if it is, courtesy of T3 resistance - but most GPs have never heard of that).

In short, TSH becomes meaningless once you start taking any thyroid hormone replacement, particularly one containing T3. 

[Clutter in reply to sue_b]

Sue-B,

TSH 0.02 doesn't mean you are overmedicated as long as FT3 remains within range.  I recommend you have a serum FT3 test before reducing dose.  thyroiduk.org.uk/tuk/testin...

I've not seen anyone able to interpret urine thyroid results on this forum.  The links below don't find that T4 + T3 urine results determine hypothyroidism.

ncbi.nlm.nih.gov/pubmed/182...

link.springer.com/article/1...

[Hidden in reply to Jazzw]

Jazzw, do you know why FT4 levels are often lower on NDT? I have noticed the same thing myself, but I have no idea why, as NDT is 80% T4 anyway...

[Jazzw in reply to Hidden]

Short answer, I don't really understand why.

Slightly longer answer, found by some judicious googling...

"Many on desiccated thyroid have lab results that show a low in range Total and Free T4 when their Free T3 gets into the optimal range (upper half). This is because desiccated thyroid (pig thyroid) is approximately 80% T4, and 20% T3, while a normal human’s thyroid output is closer to 94% T4 and 6% T3."

(Found at Tiredthyroid.com)

So thinking about it, a human body would "see" that 20% pig thyroid T3 as 6%... This is making my slightly foggy head hurt today, but I think there's a part of my brain that thinks there's something about that that makes sense - that the FT4 level be correspondingly lower. Or I could be writing rubbish.

Let's see, one part FT3 to four parts FT4

compared to

One part FT3 to fifteen and a half parts FT4... 

Nope, can't make the synaptic leap today! 

Maybe post it as a new question? I'd love to know the answer!

[sue_b]

Thanks Clutter

I'll do a bit more research about the urine testing  

[Glynisrose]

If it feels good do it!  Never mind numbers.

[debjs]

My TSH has been supressed on NDT for past 3 years & endo tolerates it as long as my t3 is in range. He takes little interest in my t4 levels which tend to be mid range or lower so as others have said it's not a good guide. 

[sue_b in reply to debjs]

Hi  Debjs

would you mind sending a pm with your endo's details?

thank you

[sue_b]

I have been on holiday , hence the tardy thank you, everyone