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

We have to be our own advocates! I also find myself researching etc. my endro and my last endro only push meds. No mention of exercise, diet, resistance training. It is disheartening to say the least. I will do all I can to not take meds. 🙏

I am confused and new to this subject and maybe you can help me. My current ctx is 350…ten years ago was 880. Can someone tell me which shows less bone turnover? Thanks

Hi @nme1985 in post menopausal women, the CTX ‘normal’ range is very wide. Depending on the lab you are using or which method of testing that the lab is using, the range could also vary a little bit. Generally CTX falls 104-1008pg/ml +/-variation of lab/testing method. Stick with one lab is best.

In hormone therapy, estrogen is mainly used for its antiresorptive function, although it has many other wonderful effects on the bone. Hence the CTX could be monitored for therapy along with yearly Dexa scan. If you are taking testosterone, get P1NP level at the same time you test for CTX is a good idea. Your current CTX level is looking great!

nme 1985,
ctx measures a fragment of collagen that is removed by the bloodstream when the bones are being broken down. It is higher if you are healing a broken bone or if your bones are still growing Or if you have osteoporosis. 880 reflects greater bone breakdown than 350. Which is great if you've fractured or if your bones are growing.
Even so, if the P1NP is high you might still be replacing the bone equal or greater than the bone you are losing.
Bone turnover, though, is important (in addition to growing bone and healing bone) for remodeling bone. You need different bone alignment and strength for variant activities. So if you were to take up parachuting, your bones would breakdown and rebuild to proctect you from breakage in this activity.
Do you really have ten years of CTX. It would be interesting to look at in terms of age and bisphosphonate use, if you feel like entering them here.

Bone markers are ephemeral.
"Human bone is continuously remodeled through a process of bone formation and resorption. Approximately 90% of theorganic matrix of bone is type I collagen, a helical protein that is crosslinked at the N- and C-terminal ends of the molecule. During bone resorption, osteoclasts secrete a mixture of acid and neutral proteases that degrade the collagenfibrils into molecular fragments, including C-terminal telopeptide (CTx). As bone ages, the alpha form of aspartic acid present in CTx converts to the beta form. Beta-CTx is released into the bloodstream during bone resorption and servesas a specific marker for the degradation of mature type I collagen."

So we measure something very specific that is limited to a short point in time.
Markers can vary (time of day, calcium, biotin, collagen intake, circadium rhythm, exercise) but they precicely measure one aspect of bone morphology. Only one well two with P1NP. Many other things can go wrong along the way to a strong bone.
Are you tickling all of us with references to magical thinking and McCormick.
I've found that all of the practitioners interested in bone morphology are ordering bone markers. And we know that all practitioners are not worth consulting. But the use of bone markers is a science advancing with the development of accurate measurement. It may be that trying to compare CTX with P1Np should be done with different time of day on each and it may be that comparing the two is a fools quest. But doesn't it make ( a sort of common) sense?

Thank you so so much!

Your baseline line sure looked “fine”. The effect on exercising on btms are still not conclusive yet. There was a small study in which it showed jogging (aerobic exercise) might decrease CTX up to 4 hours and increase P1NP transiently. However this seems age and sex dependent while other studies were not reflecting this conclusion. If you stopped jogging for your subsequent testings, then comparison won’t be under same consistency.

The more intersting presentation is your two readings following baseline. There were no obvious or significant P1NP increases as expected. Had you experienced bad side effects or sickness that made you skipping doses? Anything unusual during first few months after commencing forteo?

Hi How do I get to have these tests done before I decide to go on medication? Does your Dr have to order them for you ? Thanks

You can have the lab test by two ways. One is to have your MD (PCP or endo/rheumy or maybe orthopedic doc) to order the lab so that your insurance could cover, although some insurance still may not cover for whatever reason. Without an MD order, you could go to Quest Diagnostics site and order the test yourself. The catch is you pay out of pocket. You could also go to an online site such as ultalabtests.com to order and bring the order sheet to Quest lab. Ultalabtests often offer sales so costs will be less.

mayblin, I was ok with the small P1NP increase, but maybe not the CTX jump. I did carefully take calcium and d3 before the injection. And have read that blood calcium levels reduce PTH in blood and that d3 might be a cause for blunted response to teriparatide. Thanks.