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.

hopefullibrarian | @hopefullibrarian | Jul 4 12:57pm

In reply to @nme1985 "Can you clarify I don’t understand the numbers?" + (show)

Hi nmee1985,
I just wrote a new comment where I tried to explain it better. You can jump to it here: https://connect.mayoclinic.org/comment/1099229/

nme1985 | @nme1985 | Jul 4 1:09pm

In reply to @hopefullibrarian "I apologize if my previous explanations about CTx to P1NP (CTx:P1NP) were unclear. Let me attempt..." + (show)

Thank you!

njhornung | @normahorn | Jul 4 1:20pm

In reply to @hopefullibrarian "Hi normahorn, I attempted to write a clearer explanation of how the ratio can be useful..." + (show)

That is basically what I wrote but I did it in a simpler manner.

hopefullibrarian | @hopefullibrarian | Jul 4 4:09pm

@normahorn, Thank you for your much simpler explanation. I apologize for being so verbose.
It seems I may have misunderstood your point in your explanation. Could you clarify whether you meant a ratio of 10:3 indicates a worse condition (losing bone) compared to 10:1, or if it actually signifies improvement (gaining bone)? If it's the former, it appears our interpretations differ.

njhornung | @normahorn | Jul 4 4:51pm

In reply to @hopefullibrarian "@normahorn, Thank you for your much simpler explanation. I apologize for being so verbose. It seems..." + (show)

If, and that is a big IF, the "ideal value of CTX/P1NP is 10, then a value > 10 would mean more bone is being lost than produced while a value < 10 would mean more bone is being produced than lost. Those of us with values around 4 should have fantastic bones.

hopefullibrarian | @hopefullibrarian | Jul 4 5:54pm

In reply to @normahorn "If, and that is a big IF, the "ideal value of CTX/P1NP is 10, then a..." + (show)

I see what's causing this confusion. You're looking purely at the value of CTx divided by P1NP, rather than as a ratio. We're comparing apples to oranges. You are absolutely correct that when dividing CTx by P1NP "a value > 10 would mean more bone is being lost than produced while a value < 10 would mean more bone is being produced than lost." That's an interesting way to look at it, and it does work.
I was taking it a step further to represent it as a ratio which is different, and admittedly more complicated. With the ratio, the larger the number in relation to 10, the better the bone turnover.
Mystery solved!
Thank you for sharing this alternative way of looking at it.

mayblin | @mayblin | Jul 6 4:48pm

In reply to @melia7 "to @mayblin About frax score: I have 4,9 for spine and 1,3 for hip. The risedronate..." + (show)

I see @melia7. Your frax scores are relatively low. Hopefully risedronate will do the trick in stopping further bone loss. Best of luck and keep us posted!

babbsjoy | @babbsjoy | Jul 10 6:28pm

In reply to @mayblin "@babbsjoy me too, am interested in what your endo will be commenting regarding your bone markers..." + (show)

My osteo specialist is recommending Tymlos, subject to a 24 hour urine test and insurance cooperation. I’ve reviewed what my insurance company’s parameters are for approval, and I should qualify. We will see!

mayblin | @mayblin | Jul 10 9:03pm

In reply to @babbsjoy "My osteo specialist is recommending Tymlos, subject to a 24 hour urine test and insurance cooperation...." + (show)

Tymlos is a wonderful bone builder. Hope a smooth path and a great success ahead of you!

babbsjoy | @babbsjoy | Jul 11 7:05am

In reply to @mayblin "Tymlos is a wonderful bone builder. Hope a smooth path and a great success ahead of..." + (show)

Thank you! I am cautiously excited to have this opportunity . Grateful, but apprehensive . I’m not a big med person, and have been blessed to not to have had to take much in the past. I know this means more meds for the rest of my life—and what comes after Tymlos is more troubling. But one step at a time! I read somewhere in these posts that someone was asked, “If you had cancer would you refuse treatment because of possible side effects? “ I knew someone who did that very thing, trying to heal holistically. I was with him as he died. So this resounded with me, as I want to continue to be active and independent. (Not that meds are necessary for everyone with osteo, but given my stats it appears to be necessary for me)