Suppressed tsh when on T3: Can anyone point me in... - Thyroid UK

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Suppressed tsh when on T3

Emyloulou profile image
14 Replies

Can anyone point me in the direction of literature that states your tsh will always be suppressed when taking Liothyronine and Levothyroxine together.

My Gp and endo have no problem with it but I’ve had a pre-op as I have to have a hysterectomy and the anaesthetist is completely freaked by it despite my ft3 and ft4 being in range and being told I take T3. He’s suggested I reduce my levo which I won’t be doing so I could do with going armed when I see him next week.

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Emyloulou
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14 Replies

Did he say why he is concerned?

Emyloulou profile image
Emyloulou in reply to Mary-intussuception

Just because it was outside the normal range at 0.003.

HIFL profile image
HIFL

Your anaesthetist is rightfully concerned, because the CORRECT dose of anesthesia is determined by your metabolism. If your metabolism is too high, as it is when hyperthyroid, you'll burn right through the anesthesia and could wake during surgery. Not a good scenario. You could demonstrate normal metabolism if your blood pressure, pulse and respiration rate are normal despite your low TSH. A resting pulse above 85 bpm is trending toward hyper, IMO.

Emyloulou profile image
Emyloulou in reply to HIFL

My bp yesterday was 120/70 and my pulse 82bpm but I’d just rushed all over the hospital to have an ecg which was also normal.

HIFL profile image
HIFL in reply to Emyloulou

If your readings are all normal, they'd have a hard time arguing that your metabolism is hyper.

MaisieGray profile image
MaisieGray in reply to HIFL

Perhaps if the anaesthetist educated himself, he wouldn't be freaked. I had three surgeries in two years and not one of them was under threat of postponement because of my low TSH due to T4/3 combo; which must be the case for the majority, if not every, T3/NDT user who requires surgery. I had a great chat to one anaesthetist who was really interested in learning about liothyronine and its benefits, and who didn't have a problem with my TSH; the other two anaesthetists expressed no concern or specific interest. Perhaps they were better educated thyroid-wise, or maybe more expert in their own field, so they took account of variables but felt able to factor them in and didn't need to freak. I wonder if those with a pituitary dysfunction, or who are post-cancer thyroidectomy and whose TSH is deliberately suppressed, will therefore be routinely refused any necessary surgery by this anaesthetist because of it? The key factor surely, is the reason for the low TSH, and its associated scenario. As Dr Kent Holtorf says: "It’s also important to know that treatment with T3 causes specific changes in lab tests that can cause concern in doctors who are not trained in this treatment protocol. Because this treatment provides the active thyroid hormone T3 that your body needs, the pituitary gland produces less TSH, and the thyroid produces less T4. At the same time, levels of T3 raise in the body. To the untrained eye, a patient can appear dangerously hyperthyroid. But to the physician who understands this protocol, these changes in lab levels are expected, and treatment is monitored based on a combination of the patient’s laboratory tests, symptoms, metabolism and reflex speed rather than just a lab number. Don’t let the numbers fool you."

Emyloulou profile image
Emyloulou in reply to MaisieGray

Thank you for reply. I’ve got to go and see him next week due to the suppressed tsh and the fact I have to have IV hydrocortisone for surgery and I’m hoping to go armed with a letter off my gp to say it is normal for me. Fingers crossed he/she will have done a bit of research before I get there!

I warned them when they took the bloods it would be under range and it won’t have helped that this was at 3pm either. I’ve even given them my endocrinologist contact details because I knew it would be an issue.

jimh111 profile image
jimh111

TSH will be suppressed by T3 or T4 if you take enough to suppress it. T3 is about 3x as potent at T4 in lowering TSH. It entirely depends upon the dose of either hormone.

A suppressed TSH suggests fT3 and fT4 combined might be too high. As both hormones contribute it's not a matter of them being within their reference intervals. Usually fT3 is around mid-interval and maintained there as fT4 fluctuates in its interval. Also if you leave too long between taking the tablets and having the blood taken you can get misleading results.

However, what really matters is your clinical condition, in particular from a surgery point of view aspects such as pulse and blood pressure. It may be that these are abnormal if you are not on medication, even if you have normal TFTs at the time. If you are showing signs of a high pulse I would reduce your L-T4 for a while prior to the surgery. If your pulse is good (70 - 80?) I'd stay on your current dose.

Emyloulou profile image
Emyloulou in reply to jimh111

My bp yesterday was 120/70 and my pulse 82bpm, temp 36.1 and my ecg which was also normal. Ft4 and ft3 are both around mid range and I feel good so really don’t want to reduce either of them. My endo is quite happy with all my results.

jimh111 profile image
jimh111 in reply to Emyloulou

Yes, that looks good. My earlier comments assume the pituitary is responding appropriately to fT3 and fT4, that it is not under-performing. Unfortunately your anaesthetist may have been got at by an endocrinologist.

Emyloulou profile image
Emyloulou in reply to jimh111

I also have secondary adrenal insufficiency so something isn’t right pituitary wise, that may also explain why I need a fairly high dose off medication to keep in those ranges.

jimh111 profile image
jimh111 in reply to Emyloulou

If the adrenal insufficiency has been confirmed by an endocrinologist you should make the anaesthetist aware as this is much more important that minor thyroid variations.

Emyloulou profile image
Emyloulou in reply to jimh111

They are already aware and I’ll be given IV hydrocortisone before and after the op. I’ll be double checking on the day though 😃

SlowDragon profile image
SlowDragonAdministrator

You need to measure your resting heart rate

A Fitbit is good for proving electronic records of this

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