Chris Kresser: The only thing the body can do in that situation is to reduce the output of T4 because that’s the primary hormone that is produced in the thyroid gland. It doesn’t really have a way of reducing T3 other than reducing conversion of T4 to T3. So you’ll often see patients that have low T4, low free T4, total T4 when they’re taking thyroid hormones. So that’s what’s happening here. “Her free T3 is 2.8,” which is pretty optimal, so if the clinician is treating toward free T3, that’s probably that’s a good target range to shoot for. “Total T3 is normal, a little toward the low end.” That’s not really that relevant when you see that free T3 is normal. “Reverse T3 is low, indicating that inflammation is not a significant part of the picture. And then total T4 is again, low.” And that’s not surprising for the reason I just recommended.
So this is pretty much exactly what you’d expect in a patient that is taking thyroid hormone. And I mentioned this in the thyroid presentation. It used to be the kind of consensus was that if you see T3 or TSH and it’s close to zero and the patient is taking thyroid hormone, then that may put them at higher risk for osteoporosis and other problems associated with facetious hyperthyroidism. But as I mentioned in the presentation some more recent research suggests that the patient isn’t really at increased risk of those conditions. If they’re taking thyroid hormone and their TSH is near zero, if their free T3 is normal, they’re only at higher risk for those conditions if their free T3 is high.
And so we look at this picture. Her free T3 is totally normal and her TSH is near zero, but that would appear not to be as much of a concern as we thought it was. And her free T4 is low, which is not a concern either. It’s just a sign that the body sees that extra T3 and is down-regulating endogenous production of T4. So in this situation, what the thing to do might be nothing. It might be that this is what works for this patient if she’s well managed and her symptoms are less and she’s doing okay. But if she’s not doing well, then the thing that I would be looking at is the autoimmune component. Oftentimes if patients need a high dose, you know they need WP Thyroid and an additional dose of T3 in order to achieve these numbers, then the autoimmune component is not being sufficiently addressed. And so these are the patients that we really need to do a complete workup and focus on immune dysregulation in order to achieve better results and reduce the amount of thyroid hormone that they need to take.