Bone turnover markers (CTX and P1NP): do you have a baseline?

FYI, I ended Tymlos in January and have been on alendronate for four months. I just had my P1NP tested; it dropped 50 percent. My understanding is that this is normal and expected, since alendronate slows down the bone remodeling process. Think about how much P1NP jumped when you were taking an anabolic. Well, it goes back down after you're done.

My CTX also fell, but not as much; I think as long as CTX stays at a reasonably low level, you're good. The ratio of the two, that many people track, is apparently not useful when you're on an anti-resorptive. I'm mostly interested in what the next DEXA says at year-end.

@njx58 i agree with you on the 'ratio' - if a perfect one exists, it definitely loses its utility once you’re on an anti-resorptive and CTX is very suppressed.

If you’re open to sharing, I’d be curious to see your numbers. What were your CTX readings at baseline (before any meds), right before starting Fosamax, and then after 4mo on Fosamax? I've wondered if CTX hits a 'floor' more quickly when starting at a lowish point.

I would like to get CTC and PNP blood markers as a baseline. Are the markers influenced by having started several months of high dose prednisone.?
Thank you

@sassysaveur, that's a good question. Yes, high and prolonged doses of prednisone can affect both bone turnover markers - reducing formation marker P1NP specifically, with effects on resorption marker CTX harder to predict from what I've read. It's good idea to have the prescribing physician monitor bone health throughout treatment.

@mayblin i’m trying to figure out which doctor should monitor what it seems like the rheumatologist who runs the GCA fast track clinic is following me for my GCA and prescribing prednisone tape along with my primary
The Bone density, I was thinking of letting my endocrinologist who has been following me for years be the prescriber and monitor of the bone growth piece. What do you think about dividing up some of the pieces of the puzzle this way?

@sassysaveur, i think any of the doctors can order a DXA scan for monitoring, but for Glucocorticoid-Induced Osteoporosis (GIOP), the "who" matters. Since your rheumatologist prescribed prednisone and will manage the taper, they seem to be in the best position to coordinate this, and i believe there are guidelines for bone protection. However, if your endocrinologist has a specific sub-specialty in metabolic bone disease, they may be better suited to manage the actual pharmacotherapy. In any case, make sure at least one of them is actively tracking your bone status so nothing falls through the cracks. Whichever doctor you choose, you can always use the other for a second opinion, as drug therapy for osteoporosis can get complicated quickly.

@kristie2 - are you using BHRT as a sole follow-up to Evenity?

I have recently finished the Evenity course and will check BTMs next week (self-pay as dr trusts only DXA). Unfortunately, the only baseline I have is prior to Evenity, but at least it's something even though I was not counseled in regards to proper preparation. So my labs next week will sort of set a new baseline for me. I assume there will be some Evenity properties still in my system to impact the results, but then I'll get the BTMs done every 3-months until I see a pattern emerge.

@singingbones I took 2 infusions of Prolia and then Reclast. Next Reclast due in September.

@singingbones kinda funny; my doc is only trusting my CTX score (no P1NP, but I am on year 1 of Reclast a bisphosphonate maybe that's the difference in doc's trust?), and he won't do a yearly dexa! He told me he'd give me a referral for DEXA but it would be self-pay; even though Medicare does cover yearly if undergoing treatment. Seeing him in a few weeks, we will see what happens!

@jozer - that is curious - I suspect that because Evenity initially builds bone and then acts more as an anti-resorptive later, my doc doesn't see the point??? I did read something online that tracked BTMs before, during and after the Evenity course - truly they are all over the map. But that's why I'm going to attempt to monitor my own for a bit since I've finished Evenity and increased HRT. My DXA was done one month after my last Evenity injection, so again, the dr was satisfied with this.

Also, my plan is to get a REMS scan every other yr when I'm not getting a DXA. I had one in 2025 that confirmed my 2024 DXA results.

I hate that I have to a-la-carte my bone journey. But, I'm learning a lot from the lovely ladies on this forum as well as the Inspire.com forum.