1. < Osteoporosis & Bone Health

P1NP and CTX results

Posted by drsuefowler @drsuefowler, May 4 1:11pm

I have had 3 sets of bone marker tests at Quest. The most recent one was May 29th. I asked to have the results sent to two doctors, not to have the same test repeated twice and not to be charged twice. Wouldn't you know, two tests were done twice, the comprehensive metabolic panel and P1NP. None of the results on the two tests are the same, even though it was the same blood draw. Calcium was 9.3 for one doctor and 9.7 for the other. P1NP was 179 for one doctor and 203 for the other. I'm wondering how reliable blood tests are!

Following are my bone marker results:

Date P1NP CTX Ratio
12/23 78 519 One month 20mcg Tymlos 15.02
5/24 190 1401 3 months 40mcg Tymlos 13.56
8/24 310 1414 6 months 40mcg Tymlos 21.92
12/24 190 1238 3 weeks 20mcg Forteo 15.34
4/25 179 or 203 912 5 months 20mcg Forteo 19.63 or
22.25

I know that my CTX is too high, but it is getting lower. Does anyone know if the markers indicate that Forteo is helping my bones? My recent REMS test showed that my small spine BMD improvement on Tymlos disappeared on Forteo. I also had marginally worse fragility and fracture risk on spine and hips than previously on Tymlos. In the last month, I have developed unpleasant side effects from Forteo. I am considering going back on half dose Tymlos.

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mayblin | @mayblin | May 8 1:28pm
In reply to @cs53 "I went from -3.5 to -2.9 in 8 mos" + (show)
@cs53

I went from -3.5 to -2.9 in 8 mos

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I appreciate this information very much @cs53! I had almost the same before- and after- T scores for my lumbar spine as yours with Forteo treatment, but it took me 22 months of daily injection to achieve it. I've been approved for a 3rd year Forteo but didn't proceed after discussing with my endo. When the time comes to use Forteo again, likely I will dose every other day. Your impressive results proved this dosing regimen could work!

The length of time for meds to remain effective after initial dosing is unclear. I will keep searching for anecdotal evidence. Thanks again for sharing your experience.

REPLY
mayblin | @mayblin | May 8 3:07pm
In reply to @drsuefowler "@mayblin, those are very good results. I'm glad to hear that I am not the only..." + (show)
@drsuefowler

@mayblin, those are very good results. I'm glad to hear that I am not the only one who has a high CTX on Forteo. I'm hoping to get the good results that you achieved. The coefficient variation percentages are interesting.

My concern about Forteo is the REMS Echolight test results. On 5/27/24, my spine showed -3.1. I was excited when on 12/12/24, it showed -2.8 after 9 months of Tymlos and 3 weeks of Forteo. Recently, on 4/29/25 it was back up to -3.0 after 5 months of Forteo. I don't know if this is significant, but it is upsetting.

My right femur BMD improved from -3.4 on 5/27/24, to -3.3 on 12/12/24, to -3.0 on 4/29/25. At the same time, my fragility score worsened from 46.1 to 48.8 to 52.8/100. Likewise, my five year risk score worsened from 30-50 to over 50/1000. I thought these medications were supposed to help trabecular bone more than cortical bone, but this is the opposite. I wonder if my exercise has helped my right femur BMD and my osteoclasts have been busy?

Thanks for input as always @mayblin.

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I didn't know P1NP tests are pretty consistent so thank you for raising this issue.

A very high bone turnover state when on Tymlos was not something described in clinical studies. Obviously you and a couple other members here are experiencing it. Wish this was studied and information are readily available for users.

Just a thought about your REMS results: I'd think the measurements have inherent variations just like Dexa scans. I'm not familiar with REMS but my Dexa reports provide LSC - least significant change at footnote. For example, in one of my reports LSC is 0.027g/cm(squared) for bmd in femur neck. Changes less than this number is deemed non-significant. That made my femur neck 3.6% bmd increase (0.680 to 0.705) or T score from -2.1 to -1.9 insignificant. In the same scan/report, LSC for spine is 0.022g/cm(squared) so my lumbar bmd 3.6% improvement (0.705 to 0.730) or T score -3.1 to -2.9 is significant. Go figure... Your r femur neck from -3.4 to -3.0 seems a big jump. Interestingly, with Dexa -> FRAX score you'd have a better FRAX score if your femur neck bmd improved. But with REMS your fragility score didn't improve, perhaps a different way of calculation/assessment?

REPLY
1 reply
drsuefowler | @drsuefowler | May 9 9:42am
In reply to @mayblin "I didn't know P1NP tests are pretty consistent so thank you for raising this issue. A..." + (show)
@mayblin

I didn't know P1NP tests are pretty consistent so thank you for raising this issue.

A very high bone turnover state when on Tymlos was not something described in clinical studies. Obviously you and a couple other members here are experiencing it. Wish this was studied and information are readily available for users.

Just a thought about your REMS results: I'd think the measurements have inherent variations just like Dexa scans. I'm not familiar with REMS but my Dexa reports provide LSC - least significant change at footnote. For example, in one of my reports LSC is 0.027g/cm(squared) for bmd in femur neck. Changes less than this number is deemed non-significant. That made my femur neck 3.6% bmd increase (0.680 to 0.705) or T score from -2.1 to -1.9 insignificant. In the same scan/report, LSC for spine is 0.022g/cm(squared) so my lumbar bmd 3.6% improvement (0.705 to 0.730) or T score -3.1 to -2.9 is significant. Go figure... Your r femur neck from -3.4 to -3.0 seems a big jump. Interestingly, with Dexa -> FRAX score you'd have a better FRAX score if your femur neck bmd improved. But with REMS your fragility score didn't improve, perhaps a different way of calculation/assessment?

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@mayblin, Thanks so much for directing my attention away from t-scores to BMD (g/cm squared). There were several figures for REM CV online, but I chose one and multiplied it by 2.77 as recommended. Your positive response about my right femur progress was so helpful. Following are my results:

Right Femur neck 10.9% BMD increase. LSC may be 5.34%
Total Right Hip 13% BMD increase. No LSC but probably similar.
Right Trochanter 12.9% BMD increase. No LSC but probably similar.
Spine 3.5% BMD decrease. LSC may be 3.96%

I am now happy about my right hip results! My spine decrease is not quite significant according to these figures.

The way I understand it, the REMS fragility score measures trabecular bone. That is my weakness and apparently is related to the risk of fracture. BMD measures cortical bone.

REPLY
1 reply
drsuefowler | @drsuefowler | May 9 11:20am
In reply to @drsuefowler "@mayblin, Thanks so much for directing my attention away from t-scores to BMD (g/cm squared). There..." + (show)
@drsuefowler

@mayblin, Thanks so much for directing my attention away from t-scores to BMD (g/cm squared). There were several figures for REM CV online, but I chose one and multiplied it by 2.77 as recommended. Your positive response about my right femur progress was so helpful. Following are my results:

Right Femur neck 10.9% BMD increase. LSC may be 5.34%
Total Right Hip 13% BMD increase. No LSC but probably similar.
Right Trochanter 12.9% BMD increase. No LSC but probably similar.
Spine 3.5% BMD decrease. LSC may be 3.96%

I am now happy about my right hip results! My spine decrease is not quite significant according to these figures.

The way I understand it, the REMS fragility score measures trabecular bone. That is my weakness and apparently is related to the risk of fracture. BMD measures cortical bone.

Jump to this post

Sorry, I think BMD measures the mineral density in both cortical and trabecular bone.

REPLY
patwerthman | @patwerthman | May 10 8:27am

I have no clue what all these abbreviations and scores are. Other than the T scores.

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