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

Posted by mayblin @mayblin, Mar 27 11:05am

Currently i am on forteo therapy with a couple bone markers tests done. However, I didnt have ctx or p1np tested before the start of forteo as a baseline, regrettably.

It is known that the CTX value varies greatly among different individuals, with a very wide range. For post menopausal women, the range could be 34 - 1037 pg/ml; while for perimenopausal women 34-635 pg/ml. Different labs also have a slight different range values.

CTX, a bone resorption (breakdown) marker, is heavily influenced by a number of factors, such as food intake, circadian variation and exercise/life style, etc.

Bone remodeling is a dynamic and complex process. CTX itself may not fully reveal the whole picture. The bone building marker P1NP, is a lot less influenced by external factors. Taking both into consideration at the same time may shed more lights than looking at CTX or P1NP alone.

For those who had their CTX and P1NP tested before treatment with a bone drug, could you share the results if you don't mind? Thanks a lot!

Interested in more discussions like this? Go to the Osteoporosis & Bone Health Support Group.

@debsinwa

I started Forteo in October 2023. I did both P1NP and CTX tests before starting the drug and just did them again (6 months later) here are my results:
8/2023 4/2024
P1NP 45.9 ng/mL 220.3 ng/mL
CTX 444 ng/mL 1293 ng/mL

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@debsinwa thank you! for sharing your treatment progress. I think you are doing great at 6mo FORTEO! Your P1NP had a great response to anabolic effect of FORTEO, much more in proportion than CTX.

How often are you and your endo planning on btm testing?

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@mayblin

@debsinwa thank you! for sharing your treatment progress. I think you are doing great at 6mo FORTEO! Your P1NP had a great response to anabolic effect of FORTEO, much more in proportion than CTX.

How often are you and your endo planning on btm testing?

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Thank you @mayblin. I am kind of on my own here - my Endo did not want to do the tests! (she said she doesn't see the need) so I asked my GP to order them and she agreed. So I guess it's up to me to ask. I'm thinking about waiting until 12 mo then do every 3 months to monitor. My GP doesn't have any experience with them so can't help with results. I am researching how to interpret the results and think the P1NP is good but is the CTX too high? Can anyone answer that?

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I went to a new endo and they agreed to do the BTM tests. They really didn’t see the need and said insurance doesn’t usually cover but agreed to order them. I don’t know if insurance will cover it but I’m going to do them. If your tests are covered by insurance are there specific codes your doctor uses or any tips on how to get them covered?

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@bluebonnet242

I went to a new endo and they agreed to do the BTM tests. They really didn’t see the need and said insurance doesn’t usually cover but agreed to order them. I don’t know if insurance will cover it but I’m going to do them. If your tests are covered by insurance are there specific codes your doctor uses or any tips on how to get them covered?

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@bluebonnet242 ppl including doctors think differently regarding btms. If your btms respond to meds and trend nicely, I think it definitely worthwhile to do them, provided insurance/you willing to pay for them. You definitely want to know if the med is working for you in the early months, and/or when you get into a tricky situation to get off of the drug. You just never know what’s going to happen during a therapy. I think it’s a fool’s game not to, especially for those who gets Dexa checked biannually.

My insurance paid everything and I do not know the codes. In some situations, have you doc write ‘medically necessary’ will help.

Maybe @gently know?

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@debsinwa

Thank you @mayblin. I am kind of on my own here - my Endo did not want to do the tests! (she said she doesn't see the need) so I asked my GP to order them and she agreed. So I guess it's up to me to ask. I'm thinking about waiting until 12 mo then do every 3 months to monitor. My GP doesn't have any experience with them so can't help with results. I am researching how to interpret the results and think the P1NP is good but is the CTX too high? Can anyone answer that?

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Hi @debsinwa you are very wise and ask great questions. Hope you’d do a 12mo Dexa too. Feel free to pm me if you like.

Wish the very best

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@debsinwa

I started Forteo in October 2023. I did both P1NP and CTX tests before starting the drug and just did them again (6 months later) here are my results:
8/2023 4/2024
P1NP 45.9 ng/mL 220.3 ng/mL
CTX 444 ng/mL 1293 ng/mL

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I’m confused now. Did both your numbers come down, or did they both go up? Is goal range for CTX to be between 300-375 and P1NP to be between 30-50?
Thanks!

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@sallyj2

I’m confused now. Did both your numbers come down, or did they both go up? Is goal range for CTX to be between 300-375 and P1NP to be between 30-50?
Thanks!

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Both of my numbers went up.
Before Forteo (August '23) they were P1NP: 45.9 and CTX: 444
6 months after started Forteo (April '24) they were P1NP: 220 and CTX: 1293
I am asking here for advice about these results. as I'm not sure either. I should have put in also that I had a compression fracture in spine in March and another in Sept. so that may also have had an effect on the numbers?

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@debsinwa

Both of my numbers went up.
Before Forteo (August '23) they were P1NP: 45.9 and CTX: 444
6 months after started Forteo (April '24) they were P1NP: 220 and CTX: 1293
I am asking here for advice about these results. as I'm not sure either. I should have put in also that I had a compression fracture in spine in March and another in Sept. so that may also have had an effect on the numbers?

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From what I’ve read, a compression fracture can cause P1NP to rise. So, would Forteo. I do t think Forteo would raise CTX, not sure about fracture healing. From reading McCormick and listening to Lane Simpson, I think you want CTX to be 300-400. P1NP not on anabolic, 30-50, but it goes higher in anabolics as it should. My numbers aren’t terribly far from there and I still fractured. If you had lumbar fracture I highly recommend kyphoplasty. Helped with pain and quicker return to exercise.

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@sallyj2

From what I’ve read, a compression fracture can cause P1NP to rise. So, would Forteo. I do t think Forteo would raise CTX, not sure about fracture healing. From reading McCormick and listening to Lane Simpson, I think you want CTX to be 300-400. P1NP not on anabolic, 30-50, but it goes higher in anabolics as it should. My numbers aren’t terribly far from there and I still fractured. If you had lumbar fracture I highly recommend kyphoplasty. Helped with pain and quicker return to exercise.

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Thank you

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@debsinwa

Both of my numbers went up.
Before Forteo (August '23) they were P1NP: 45.9 and CTX: 444
6 months after started Forteo (April '24) they were P1NP: 220 and CTX: 1293
I am asking here for advice about these results. as I'm not sure either. I should have put in also that I had a compression fracture in spine in March and another in Sept. so that may also have had an effect on the numbers?

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@debsinwa this (fractures, sorry to hear that) changed things. I was puzzled by your high ctx at this stage of forteo. After a fracture, btms usually increase. And the degree and length of the increase depend on the size of the bone, the bmd of the fractured bone, the surface of the factured bone, the need for surgery and the degree of immobilization. So your btms results might have been influenced by the fractures. Most studies usually observe btms after a fracture for up to 1 year after fractures.

@sallyj2 ctx and p1np usually go in tandem during antiresorptive or anabolic therapy, due to coupling effect. In anabolic therapy, they are bit trickier to read.

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