Question on CTX numbers

dna41, you have an excellent doctor, following you closely. Few get the close care that you really need after Prolia to prevent rebound. Is the the baseline after Prolia. How long were you on Prolia. The climb after the infusion was really from the Prolia. The descent from 618 down to 424 is because of the Reclast.
You probably know this already but Prolia preserves all of the cells that breakdown bone in their last stage of development. When you stop Prolia they all mature at once and can cause multiple fractures in people who don't have doctors like yours. CTX measure the remnants of the bone breakdown. So we this number to determine osteoblast presence. At CTX of 424 those cells are quite high, but Reclast is working. I would want the infusion.
Cheers to your doctor, I think your bones have been saved from fracture.
If you had very high P1NP (the standing marker for osteoblasts-- the cells that build bone. 424 would be ok. My CTX is 427pg/ml but my P1NP is at 179 because I'm on Forteo and building bone as fast as it gets broken down.
Prolia drives down the osteoblasts and osteoclasts, so that you aren't remodeling bone on Prolia. I think you've had a near mill.

Gently,

Thanks for the intel on CTX numbers; the topic is very timely for me.

Last year, prior to Reclast and after Tymlos/Evenity, I had a CTX of 298. This year, my CTX shot up to 391. I’m still not sold on Prolia, but my doc is. He has also suggested Forteo or ramping up Tymlos to see what might work. So that we can make the best decision, we agreed that I would have a follow up CTX and P1NP along with vitamin D, creatinine and PTH labs in 90 days.

Here’s something I discovered: Large doses of biotin can perhaps skew lab results up or down based on testing methods used by the lab. I found this out after reading the label on the recently-added-to-my-supplements collagen bottle.

Does anyone know anything additional about this?

Thanks, all, for your guidance and information. Happy Sunday. Cheers!

Yes: when doing the CTX test, you must avoid biotin. From Quest:

"Some supplements have amounts many times the adequate intake, with megadoses in the 5,000 µg to 10,000 µg range. Biotin’s half-life is approximately 2 hours, so abstinence for 8 hours may be sufficient to minimize interference. However, it is highly recommended that patients taking massive biotin doses abstain for 72 hours before having blood specimens drawn for laboratory tests"

Also, CTX must be done in the morning.

Thank you again. Yes, baseline was after Prolia which I was on for 6-7 years. I don't have a P1NP number since my doctor doesn't order it. Were you on Reclast prior to Forteo?

@beanieone , Yes Keith McCormick in "Great Bones" advises to stop biotin and collagen two days prior to CTX which I have done twice for my CTX.

Thank you for the info, @debbie1956.

Although I reported the collagen/biotin in my list of current supplements, my doc either missed it or didn’t know it could cause a false read. Either way, my fingers are crossed that when I repeat the test in October, sans collagen/biotin, my scores will be back down to normal - whatever that is ;).

Have a great week! Cheers!

Has anyone else had there CTX Lab work denied by insurance? Mine was not covered and when I called and asked why, I was told the billing code is not covered. I asked if there was a billing code that would be covered after explaining why I was doing it and she said she could not tell me that.