Conversation between Chris Kelly and Sam (Ben Greenfield podcast) about interpreting cortisol test results. Discussion covers reference ranges, Mark Newman’s visual "speedometer" indicator, the difference between total cortisol production vs. 24-hour free cortisol, scenarios where free cortisol is high despite low adrenal output (often due to poor clearance by the liver related to hypothyroidism), and example numeric outputs cited (total ~8,400 vs. metabolized ~3,000).
Questions this video answers
~8,400 (spoken example)
~3,000 (spoken example, described as "3,000 odd")
Chapters
And so if you define your reference range around people who are not feeling good, you end up with a really weird reference range that's typically very wide. So Mark Newman has done a fantastic job of defining these reference ranges and he's created this visual indicator that looks a bit like a speedometer. And you can see there's two yellow stars either side of the speedometer and then the little red arrow indicates your level. And you can see for the total.
The total cortisol production and the 24 hour free cortisol are both extremely high. So not only are you making a lot of cortisol, it's also hanging around like you're not clearing it that well. So, you know, the overall picture is of a lot of cortisol.
Now, in some cases, for example, from what I understand, you could not be making a lot of cortisol, but it wouldn't actually be getting cleared very quickly. And so you could show as having high cortisol even if you weren't producing that much cortisol, is that correct?
That's right, yeah. So we see that quite a lot. So someone who's not making a lot of cortisol, so the total output from the adrenal glands is quite low, but then you still see high free cortisol. And that's usually because the. Either the liver is not clearing it very well, and that's because of hypothyroidism. And so that's a really, really common kind of pattern that we see amongst the athletes that we test.
And if that were the case, if someone went out and they got a blood test, they would test for. They would test and the test would show, what would it be? High cortisol. Even though their cortisol is actually low.
Yeah. Normally it's still within the normal range, but the total cortisol output, so you see where you're at 8,400, they would be much closer to the bottom of the range for the metabolized cortisol. So they'd be down at like 3,000 odd.
And they would be under the impression that their adrenal glands were working just fine, when in fact their adrenal glands were not producing much cortisol or as much cortisol as would be ideal, because cortisol is basically being, or not being cleared very quickly. So they're showing on their tests results as normal or slightly high cortisol, when in fact cortisol production is not that great.
