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

Posted by mayblin @mayblin, Mar 27, 2024

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.

@gently

loriesco the summaries of demineralized bones sounds very interesting. Can you tell me more. Do these summaries include, well, which bones. Could they have done this for your neck before the bone-crumbling surgery. It seems like this is a new technique with MRI involving different sequences. I'd be curious about what type of reading you get. Numbers?
Information about bone matrix before surgery is so crucial.
I was responding to the information that on the anabolics P1NP numbers lessen. Which they do after you've been on it for while, plateau at 6 to 12 months and then lessen.
I love the way you "paint the street," with your responses.
How often do you get the summaries.

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@gently I'll have to ask my doctor about this: "Information about bone matrix before surgery is so crucial" when he returns from Paternity leave. Also, my numbers with the P1NP and CTX did what they were supposed to do when they were tested. But I'm sorry I don't have the numbers handy. I suppose I should ask for a retest. As I believe I am coming up on a year next month or in June from the first test. With ALL the tests they DID do before my surgery - I know they were shocked when it happened. HOWEVERf - the upside was using my own bone in the blender to fill the cage with so I didn't have any infection risk from cadaver bones or synthetic. Everyone seemed happy with that. I know I am 6 pages in a USCD medical text book now on how to do a cervical spine surgery! (they said they did absolutely EVERYTHING all in one surgery! 😉

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@mayblin

Hi @jennirdh , I am very sorry to hear that you suffered vertebrae compression fractures related to prolia rebound. Hope you have a speedy and great recovery that lead to minimal aftereffects.

Your bone makers are very interesting and thank you very much for sharing them. Since you had 5 shots of prolia then followed with boniva for 11 months (please correct me if I got this wrong), your bone markers may still reflect some tailend effects of prolia cessation, in other words, they might reflect the combined effects of prolia cessation (end stage) and early stage of tymlos' therapy.

To me, the good news is CTX is stabilizing. I have a neutral view towards your latest two p1np readings as you don't have a baseline. Some people get p1np increase only in early months of tymlos treatment as shown in clinical studies. So your p1np 112 might be the "spike" but there is no baseline to compare with - let's hope this is it! I agree with you on the importance of a baseline. I don't have any either prior to my forteo treatment. Later when I needed it, it was too late. I could've easily used a double dose of estradiol after Forteo which clearly was proven not necessary by bone markers as well as dxa results.

Curious, was your CTX monitored during Boniva?

Wish you the best, and a great success with Tymlos!

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Thank you @mayblin for your insights! I, too, think perhaps the 112 P1NP is my spike and that gives me hope that Tymlos is working. The CTX was at 79 when in Oct 23 I was due for my Prolia and decided to stop, so it had been 6 months since my last one. It was only the second time it had ever been checked during my time on Prolia, and I have no actual starting baseline with that either!
Do you think at my next labs the CTX should show even lower? I am thinking that would be good. Will be repeating in 2-3 months. Hopefully by then I will have found a better healthcare professional to quarterback this disease with me. Thank you for caring, can you tell me a bit more about your being on estradiol?

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@loriesco

@gently I'll have to ask my doctor about this: "Information about bone matrix before surgery is so crucial" when he returns from Paternity leave. Also, my numbers with the P1NP and CTX did what they were supposed to do when they were tested. But I'm sorry I don't have the numbers handy. I suppose I should ask for a retest. As I believe I am coming up on a year next month or in June from the first test. With ALL the tests they DID do before my surgery - I know they were shocked when it happened. HOWEVERf - the upside was using my own bone in the blender to fill the cage with so I didn't have any infection risk from cadaver bones or synthetic. Everyone seemed happy with that. I know I am 6 pages in a USCD medical text book now on how to do a cervical spine surgery! (they said they did absolutely EVERYTHING all in one surgery! 😉

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loriesco, marvelous story.

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@jennirdh

Thank you @mayblin for your insights! I, too, think perhaps the 112 P1NP is my spike and that gives me hope that Tymlos is working. The CTX was at 79 when in Oct 23 I was due for my Prolia and decided to stop, so it had been 6 months since my last one. It was only the second time it had ever been checked during my time on Prolia, and I have no actual starting baseline with that either!
Do you think at my next labs the CTX should show even lower? I am thinking that would be good. Will be repeating in 2-3 months. Hopefully by then I will have found a better healthcare professional to quarterback this disease with me. Thank you for caring, can you tell me a bit more about your being on estradiol?

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I see. I was thinking if you had CTX monitored regularly during Boniva, they might've given you a clue as to if Boniva is adequate in keeping rebound in check.

Your plan of repeating bone marker labs sounds great! Either a decrease in CTX or increase in P1NP or both is a step toward the right direction. CTX is unpredictable at this stage in my view because of the combined effects of prolia cessation and Tymlos.

The main purpose of my estradiol use is for its antiresorptive effect - as a followup after Forteo. Thanks for asking. There are 3 dosages for estradiol patches named:
Ultra low dose: 0.014mg/day
Low dose: 0.025mg/day
'Regular or standard' dose: 0.05mg/day

The dose of 0.0375mg/day is also available, so are higher doses greater than 0.05mg/day.

Many endos use standard dose for bone effects. However low dose was studied also and appeared to be effective but might be dependent on age and other factors. I elected low dose to start with monitoring bone markers, considering that my frax score is fairly low. Turns out this dose worked very well for me: CTX went down to 163 and dxa had further improvements after 6mo estradiol. Without a baseline bone markers prior to treatments, monitoring btm periodically to see the trend is useful in my case.

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This has certainly been an interesting thread to read. Thank you, to all, for leaving info. I’m 65, surgical menopause at age 40. Been on HRT or BHRT for all but 2 years, during the big scare of HRT.
I started Evenity 8 months ago….thank goodness it’s almost over. I’m anxious to get a new DeXA scan to see if it’s been worth the years process.
CTX and P1NP were done before starting Evenity, after the 4th shot and after the 8th shot.
CTX 333/173/139
P1NP 37/26/19.
These were done at about 7:30AM, all fasting, all w/o supplements 4 days before and all with no exercise within 48 hrs. I had thought my P1NP would go up or at least not go down. Curious to see what my last labs will show. At this rate I’ll be out of range

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@leslie559

This has certainly been an interesting thread to read. Thank you, to all, for leaving info. I’m 65, surgical menopause at age 40. Been on HRT or BHRT for all but 2 years, during the big scare of HRT.
I started Evenity 8 months ago….thank goodness it’s almost over. I’m anxious to get a new DeXA scan to see if it’s been worth the years process.
CTX and P1NP were done before starting Evenity, after the 4th shot and after the 8th shot.
CTX 333/173/139
P1NP 37/26/19.
These were done at about 7:30AM, all fasting, all w/o supplements 4 days before and all with no exercise within 48 hrs. I had thought my P1NP would go up or at least not go down. Curious to see what my last labs will show. At this rate I’ll be out of range

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Thanks for sharing @leslie559!

Have you been on HRT/BHRT for the past 8 months concurrently with Evenity treatment? If so, do you mind sharing your estradiol dose and dosage form? Thanks.

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@mayblin

Thanks for sharing @leslie559!

Have you been on HRT/BHRT for the past 8 months concurrently with Evenity treatment? If so, do you mind sharing your estradiol dose and dosage form? Thanks.

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I have been. I’ve just recently been reading on some being discontinued during their Evenity year.
I’m on Estradiol, 1 mg tablet, taken daily before bed

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@leslie559

I have been. I’ve just recently been reading on some being discontinued during their Evenity year.
I’m on Estradiol, 1 mg tablet, taken daily before bed

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I see. Below is a chart for the percentage changes of P1NP and CTX during 12 month romosozumab (Evenity) treatment, data from its phase 3 study. It looks like the best time to see bone formation marker P1NP surge is during first two months, you might have missed it due to timing, although a concurrent HRT might affect bone markers response.

Curious, has your prescribing physician for HRT discussed various dosage forms for estradiol? Many obgyn prefers transdermal form nowadays due to the benefits of lower risk of blood clots (by bypassing liver’s first passing metabolism) and a more stable hormone level, among others. You might want to ask. From what I read, 1mg oral tablet is approximately equivalent to 0.05mg/day transdermal patches of estradiol.

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@mayblin

I see. Below is a chart for the percentage changes of P1NP and CTX during 12 month romosozumab (Evenity) treatment, data from its phase 3 study. It looks like the best time to see bone formation marker P1NP surge is during first two months, you might have missed it due to timing, although a concurrent HRT might affect bone markers response.

Curious, has your prescribing physician for HRT discussed various dosage forms for estradiol? Many obgyn prefers transdermal form nowadays due to the benefits of lower risk of blood clots (by bypassing liver’s first passing metabolism) and a more stable hormone level, among others. You might want to ask. From what I read, 1mg oral tablet is approximately equivalent to 0.05mg/day transdermal patches of estradiol.

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Forgot to attach the graph, here it is:

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@mayblin

Forgot to attach the graph, here it is:

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I had read about the fact that most, if not all of your gains on Evenity come within the first 4-6 months, which poses the questions of why 12 then. But, with that, my 4 month marker for P1NP went down from my baseline. This graph shows the drop of P1NP returning to baseline at about month 6. My fear is in being a non-responder. But I guess….we’ll find out in September. Just 4 more months of shots and waiting.

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