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.

babbsjoy | @babbsjoy | Jul 1 11:09am

In reply to @rola "Very impressed with the medical care you are receiving! Sounds like you are in very good..." + (show)

@rola, Thank you, I am relieved to have access to a practice that appears to be thorough and up to date on this often overlooked issue!

melia7 | @melia7 | Jul 1 12:41pm

In reply to @babbsjoy "Just received my bone marker test result. They are fasting for 12 hours and blood drawn..." + (show)

Could you please mention in what units are CNX and P1NP? It would be interesting to know also how your doctor commented your results?

babbsjoy | @babbsjoy | Jul 2 10:01am

In reply to @melia7 "Could you please mention in what units are CNX and P1NP? It would be interesting to..." + (show)

I have not seen the doc yet to discuss, it is scheduled though!

melia7 | @melia7 | Jul 2 1:47pm

reply to @mayblin
About values of bone markers. I have just made the tests (and I have yet to start a treatment (risedronate).
CTX was 0,57 microgram per liter and nearby they mentioned 0,18-1,06 microgram for postmenopausal women.
P1NP was 76,2 microgram per liter, and it was noted that normal value should be from 20,25 to 76,3 microgram.
I am not sure how micrograms are translated to picograms, which are used in the USA. Sure, it is interesting to compare values before and after treatment. What were yours?

njhornung | @normahorn | Jul 2 2:03pm

In reply to @melia7 "reply to @mayblin About values of bone markers. I have just made the tests (and I..." + (show)

Multiply your result by 1000 for the CTX value.

hopefullibrarian | @hopefullibrarian | Jul 2 3:20pm

In reply to @babbsjoy "Just received my bone marker test result. They are fasting for 12 hours and blood drawn..." + (show)

babbsjoy, You're not on any osteo meds? Have you ever taken any? I ask, because your BTMs are actually pretty darn good. Dr. McCormick, author of Great Bones, says the ideal P1NP range is 20-60, and CTx should be 350 (375 at a stretch) or less. The ratio of P1NP to CTx, per Dr. Mc should ideally be somewhere around 1 to 10 to *maintain* bone if you're not on meds. Yours is about 1.75 to 10. That ratio, implies that you should be growing bone. Bear in mind--your scores are a snapshot, and could vary by quite a bit day-to-day, but I would kill for scores like that when I eventually try to go med free.

babbsjoy | @babbsjoy | Jul 2 5:07pm

@hopefullibrarian, Thank you! I am early in this journey. I have met with my osteo specialist once, and she ordered myriad tests and referred me to physical therapy. I have just completed all the labs, tests, and physical therapy (really helping my upper back) and will meet with her next week. She said once she reviewed all the tests and labs, we would talk meds. She said my spinal dexa at -3.6 meant I would definitely be recommended meds. (And she kind of wanted to start talking meds at that time, asking me if I had any preferences. I was doing my ostrich impression at the time—head in hole and not researching yet, hoping it would all just go away. )

We will see! I have a feeling that since I’ve had no fractures and not ever any meds, she may not recommend the anabolic I desire (and insurance may not cooperate either). I have my long list of questions ready!

mayblin | @mayblin | Jul 2 7:14pm

In reply to @babbsjoy "@hopefullibrarian, Thank you! I am early in this journey. I have met with my osteo specialist..." + (show)

@babbsjoy me too, am interested in what your endo will be commenting regarding your bone markers as well as treatment plan. Please keep us updated. Thanks a lot!

mayblin | @mayblin | Jul 2 7:40pm

In reply to @melia7 "reply to @mayblin About values of bone markers. I have just made the tests (and I..." + (show)

@melia7 your CTX is in mcg/L, that is, micrograms per liter. To convert to pg/ml (picograms/ml, the units used here in the US), you multiply 1,000,000 then divide it by 1000:
(0.57 x 1,000,000)/1,000 = 570 pg/ml, just like @normahorn said to multiply your lab value by 1000; as 1 mcg = 1,000,000 pg and 1 Liter = 1,000ml.

Your P1NP has the same unit as used here in US mcg/L.

What's your frax score if you don't mind sharing? Will risedronate be your first bone med? What's the plan of length using risedronate?

I don't have a baseline bone markers unforturnately, although I had P1NP tested at 13 month of FORTEO which showed a tremendous boost (400). Later the bone markers were monitored periodically and they are trending nicely.