Suppressed TSH

[Clairewalker751]

Hi all been a while since I posted just looking for reassurance regarding having a suppressed TSH as medichecks Dr is saying I'm over medicated I know I'm not as these were my results.

TSH 0.232 (0.27-4.2)

FT4 17.7 (12-22)

FT3 4.45 (3.1-6.8)

I take 150 of levo and 3mcg of T3 the GP doesn't know intake T3

I have a resting heart rate of 60 and if anything I'm feeling very slightly hypo at the moment.

Thanks in advance x

[jimh111]

Your TSH is subnormal, too low for your fT3, fT4 levels. There can many reasons for this one of which is a period of thyrotoxicity which can down-regulate the hypothalamic pituitary thyroid axis. This might be so in your case as you were previously taking lots of T3 and T4. Your axis might recover, it might not. In any event you are not currently over-medicated rather your pituitary is not sufficiently responding to your hormone levels.

[Kipsy]

Claire- You are definitely not overmedicated as your T3 is well within range. Two endo’s that I have consulted agree with this view. My TSH is very suppressed, much lower than yours, and both endo’s are happy to keep me on my current dose of 100mcg T4 and 15mcg T3. However, my GP was concerned as her knowledge of thyroid issues is more scanty. Below is a copy of what I wrote for my GP to read when she was worried about my very suppressed TSH. She called me in to discuss the threat of osteoporosis but thankfully she is lovely and was happy to be guided by my research. I agreed to a Dexa scan, which was normal. I then gave one of the endos the same document as I happened to have an appointment booked anyway, although I doubt he needed it. It reads as follows:

Suppressed TSH and Osteoporosis

1. It is well known that endogenous hyperthyroidism gives rise to an increased risk of bone thinning. This is partly due to the direct action of TSH on osteocytes, cells concerned with bone density.

2. This increased risk of bone thinning does not apply to a hypothyroid patient who is taking T4 or a T4/T3 combination, even if their TSH is suppressed, as long as FT3 levels are within range. Effects on bone density are not just related to TSH. In hyperthyroidism, TSH is suppressed and FT3 high. In this case, bone density will be affected both by TSH suppression and the extra metabolic activity activated by high FT3. For a hypothyroid patient on replacement therapy with a suppressed TSH, FT3 is ‘normal’ so the joint effects do not apply. There is no good evidence that a suppressed TSH when being treated for hypothyroidism results in an increase in the risk of bone thinning as long as FT3 levels are within range.

3. TSH will be suppressed when a patient takes T3. A low or suppressed TSH on replacement therapy is not the same as a low TSH in primary hyperthyroidism. A suppressed TSH does not mean hyperthyroidism if a patient has been previously diagnosed as hypothyroid. TSH is not a thyroid hormone but is from the pituitary gland. If a patient is ingesting exogenous T3 directly, the thyroid gland has no/less need to manufacture T4 as a storage pro hormone for subsequent conversion to T3, therefore the pituitary gland doesn’t generate as much TSH in order to stimulate the thyroid gland.

4. I have no symptoms of overtreatment such as palpitations, tremor, sweating etc and my FT4 and FT3 levels are both well within normal ranges. In addition, my resting heart rate is normal.

5. Furthermore, there is a body of responsible medical opinion that agrees with maintaining a dose that suppresses TSH as this reduces the number of Hashimoto’s flares and therefore delays the complete destruction of the thyroid gland. At diagnosis, my Thyroid Peroxidase antibodies were … (range <60) and have fallen to … (range <34) since my TSH has been suppressed. This represents a …% reduction in antibodies.

6. As an aside, The Rotterdam Study into atrial fibrillation finds no association between TSH and AF and a meta-analysis of patients with TSH suppressed below 0.1 found one extra hip fracture per 1,000 patient-years.

[Clairewalker751 in reply to Kipsy]

Thank you so much kipsy! My GP is unaware of anything they did a blood test a few months ago won't be called for another blood test until next year, glad to hear your doing well! and I will keep what you wrote in case my GP gets involved x

[Kipsy in reply to Clairewalker751]

Glad you’re not being called in! Take care, Claire. X

[Mickeydooley in reply to Kipsy]

Very interesting and useful information for me just now. I was searching for this sort of information and came across your reply. I am awaiting my latest results following an endo review where he talked about adjusting my dose of T4 and t3 if my TSH levels were low/suppressed because it was associated with osteoporosis. Thanks.

[Kipsy in reply to Mickeydooley]

Glad it’s of help. My endo later wrote to my GP categorically stating that a suppressed TSH was nothing to worry about as long as T4 and T3 were in range.

[Everdean in reply to Kipsy]

I have just found your reply which relates to my problem with my GP. I would like to print a copy of the reference work you quoted here to give to my Dr but please would you tell me where you got it from. I think the Dr would accept it more if I could say where it was from. Thank you Kipsy.

[Kipsy in reply to Everdean]

Hi- I’m not medically trained and no expert but I wrote it myself. I was diagnosed about 3 years ago and have learnt a great deal from this brilliant forum since, having known nothing previously. Sorry but it’s not an official document. Good luck.

[Kipsy in reply to Everdean]

The Rotterdam study was something I found somewhere- it might have been in the ThyroidUK website. Sorry- I can’t recall but have a look there or perhaps Google??