Dr. Amy Nett: This is really tricky. Chris and I have a patient that we both work with and she has the exact same thing but like her TSH is .00001 and her free T3 and free T4 are pretty normal. And she, this particular patient, had a history of an eating disorder and she had purposely taken elevated thyroid doses for a long time to try to lose weight, so we were actually thinking, well, maybe this was just like a long-term kind of suppression, and what I ended up doing is I tried weaning her off of her thyroid medication, her T4 and T3. She did not enjoy that so we kept her at sort of the the lowest dose that she felt was tolerable and her TSH was still something like .001. And then I ran a number of tests looking at thyroid functions. So sorry, looking at hypothalamic functions.
So we ran LH, FSH, growth hormone, I think we did like ACTH, it just seemed, like, are there abnormalities in any of these other hormones, I’m sorry, pituitary hormones, I apologize. So we ran that blood panel, that looked completely normal. I think, I don’t remember, if we actually did a pituitary MRI in her to make sure there wasn’t an adenoma that was, like a microadenoma causing some sort of disruption. And when everything looked completely normal, we kind of shrugged and said “I don’t know” because I’m not sure if TSH suppression, you know, .01 is is not that bad compared to the .0001 or whatever she was. I don’t know if that’s going to be associated potentially with risks of osteopenia, osteoporosis, maybe cardiovascular risk. I don’t know.
The problem is if the free T3 and free T4 are normal and she feels good, it’s really difficult to then like wean her off of the thyroid medicine. So I don’t have a good answer. I have concerns about whether or not that degree of TSH suppression is okay. I’m not sure. But you also have to look at the free T3 and free T4, and if those are in the normal and/or a low-normal range and she feels good, not hyperthyroid, maybe that is the appropriate dose for her to be on. So I think we have more to learn there. I’m definitely interested because I’ve seen this in a couple patients now. So I probably would offer her the idea of decreasing the Nature-Throid very slightly, following her up symptomatically along with the labs and just see what she thinks.