Comparing blood tests - question.

[MCDW]

I was just looking back over past blood tests, and I'm struggling to work out whether my FT3 and FT4 have improved or not as the 2 tests have different ranges. Can someone with a more mathematical brain than me please help. (There was an increase in levo between the 2 tests.)

Earlier blood test

Free T4 17.6 (12.0 - 22.0) pmol/L

Free T3 4.0 (3.1 - 6.8) pmol/L

Latest blood test

Free T4 20.5 (9.00 - 22.70) pmol/L

Free T3 4.5 (3.50 - 6.50) pmol/L

[SeasideSusie Remembering]

MCDW

FT4:

Ist test 56% through range, 2nd test 83%

FT3:

1st test 24% through range, 2nd test 33%

Both have increased, FT4 by a lot more than FT3.

Did you do both tests under the same conditions ie early morning and leave off Levo for 24 hours?

What was TSH for both tests?

[MCDW in reply to SeasideSusie]

Thanks for that SeasideSusie.

Yes - both tests done early (ish) morning, fasting and no Levo for 24 hours.

TSH (1st test) 1.31 (0.27 -4.20) mU/L. (was on 75mcg Levo prior - dose then increased to 100 mcg)

TSH (2nd test) 0.09 (0.35 - 5.50) mU/L (on 100 mcg Levo)

That seems to make it very clear that I'm not converting well. I've just started adding 1/4 tablet T3 daily (to Levo 100 mcg), will increase to 1/2 tablet in a couple of weeks - and then get re-tested in about 6 weeks. I'm expecting to see an increase in FT3 - but what should I expect to see with TSH and FT4?

Thank you

[SeasideSusie Remembering in reply to MCDW]

MCDW

TSH may lower or become suppressed and FT4 may lower. Retest 6 weeks after you increase dose to 1/2 a tablet, I actually need 8 weeks after a dose change for results to stabilise and for me to feel the full effects.

[MCDW in reply to SeasideSusie]

Many thanks. Not looking forward to the conversation with my GP as she told me to reduce Levo dose (alternating 100/75) as she claims my low TSH could cause osteoporosis and heart problems. I have ignored her and continuing on 100. (And she knows nothing about me adding T3.)

[SeasideSusie Remembering in reply to MCDW]

MCDW

Snap! Mines the same, I don't mention that I take T3 and I take less Levo than they prescribe.

I'm trying to gather evidence that suppressed TSH isn't going to give me osteoporosis. Also I am being investigated for heart problems and may end up seeing a cardiologist, but there's very poor heart history so it's likely to be that rather than suppressed TSH but have to get some convincing evidence.

[MCDW in reply to SeasideSusie]

It has made me think that once I get my FT3 raised I should possibly consider reducing the Levo a touch. Will get private bloods done at 6 - 8 weeks and post for comment/advice.

Please post your evidence around suppressed TSH as and when you find it - I'm sure there are many of us who would welcome it. I find it hard to believe that low TSH would cause osteoporosis if the patient is fit and well and undertaking reasonable levels of weight bearing activities. (After all, as we age we all do lose some bone density anyway.) And wishing you all the best in relation to your heart investigations.