P1NP and CTX

[Verauk]

Hello Everyone

Does anyone here are familiar with these two blood tests :P1NP and CTX?

Thanks

[beckyiswell]

P1NP measures bone formation and CTX measures bone resorption. It is important to have these blood tests done before starting medication to have a baseline for comparison after being put on osteoporotic medications.

[Verauk in reply to beckyiswell]

That's what I tought( have these done BEFORE medication, but my Doctor did not ask it. Shall I do now( start AA 8 months ago)?

[Fruitandnutcase in reply to Verauk]

You have to wonder how many - if any - patients have those tests done before starting medication.

It is the same with my arthritis. I take hydroxychloroquine- you ought to have a baseline eye test with CT scans done before you start hydroxy and then every year afterwards. I know because my husband is a retired optometrist but so many people I’ve come across have never heard of that or had it done because they haven’t been told about it.

[beckyiswell in reply to Fruitandnutcase]

I've taken hydroxy chloroquine for at least 7 years or more, and I just had the specific eye test done last year for it. Did not have CT done.

[beckyiswell in reply to Verauk]

It wouldn't hurt.

[Verauk in reply to beckyiswell]

Yes. I will talk with my doc. Thanks

[beckyiswell in reply to Verauk]

You're welcome.

[Jemima48]

I wasn't given them before I started on medication and trying to get my doctor to let me have P1NP tests has been like getting blood out of a stone. I'm particularly keen to have them as metalwork in my spine makes it impossible for DXAs to be read except at my hips (and I'm on teriparatide, which mainly operates on the spine, so don't know how he expects to find out how much, if any, improvement there's been).I gather very few hospitals in the UK are able to process these results, which probably helps explain his reluctance - he claims he's needed to do a lot of chasing up.

Would be interesting to hear other people's experiences.

[Verauk in reply to Jemima48]

Exactly. I'm afraid to talk with my doc ,about it and he finds that I'm not trusting him.

[Jemima48 in reply to Verauk]

I wonder if this is a general pattern. It's difficult not to sound as if you don't trust them, but, after all, practitioners don't all agree!I think mine believes that, since teriparatide almost always works, it's enough to take it on trust, but my P1NP results (I've only managed to get two, nearly a year apart) seem to show such a tiny improvement I wonder if it's worth taking something that could be damaging in the long-term. (I know the black box warning has been removed, but even so ...)

[questionably]

I'm in the US and we are having the same discussions with doctors who don't want to write for labs for P1NP and CTX. The endocrinologist I see has been ordering them for 23 years. Some docs don't want to make the effort to understand how they work. But it isn't difficult. Here we can order our own labs, but then we have to pay for them.

They are expecially imporant before starting medication so you can tell if the medication is working for you. I hear of people taking teriparatide for two years without improvement.

You want to see a rise in P1NP after two months on the anabolics--Tymlos and Forteo. And a drop in both, especially CTX on bisphosphonates.

Only specialty labs process these tests; the bloodwork is shipped frozen to the few labs which process them.

[Cilla65]

Hi, my personal understanding after my visit with a private specialist in Italy is as follows:

P1NP shows the new born formation

CTX shows the bone loss.

Also the BAP shows new bone formation so it does osteocalcinand Ostase. These last 3 are less focused than P1NP by doctors for some reasons. However my specialist prefer them (maybe more available???). I am not taking medication (tscore -4 at my spine) and was not offered any, my exams show low CTX and medium bone formation from BAP, Osteocalcin, and also Ostase. These results seem to suggest that my problem is not really loss of bone not compensated by bone creation but rather a problem with collagen. I started to have hydrolized collagen at the maximum dose 15 gr before seeing the specialist with also great results for my vitreous condition which caused to me two retina rapture in 2021 and 2022. There is only one collagen certified by the national pharmaceutical agency in Italy which is the one I am taking. Because collagen builds the net on our bones where minerals deposit this could be well my issue together with low vitamin D.

On the drugs front I understand that with high bone turn over measured with the above exams together with your scans, anabolic agent can be taken only for 2 years and (super costly so only given if there are fragility fractures) after that they are ineffective or damaging, then you can either pass to Prolia or similar which helps to maintain or improve your bone density by suppressing the bone loss and not depressing too much bone formation (including the bone you have acquired with the anabolic agent) this proved to be effective for about 10 years, then you pass to bisphosphonates which suppress the bone loss and mitigate the rebound fractures after Prolia, the bone you preserve however is degraded old bone, Surely better than nothing. So when you start the drugs it is difficult to come out and you need to do the tests to be sure that it is the right path to you, we are all different and low bone density depends on many different factors. In my situation as I do not qualify for anabolic (I can only go privately on bio identical hormones therapy) there is no sense to suppress my bone loss as I already have a low value which may also suppress my medium bone formation score. I will redo the tests in June and will see. Have a great day! 🤗

[Verauk in reply to Cilla65]

Very interesting informations. Thanks

[CinnamonRose in reply to Cilla65]

That is very helpful and a clear explanation of the difference. There does seem to be quite a wide difference in treatment between hospitals.