Is Anyone Else Tracking Your P1NP to CTX Ratio, While Taking Tymlos?

I think this is a great idea. Conceptually, when the ratio favors P1NP over CTX as an indicator of bone building, that’s pretty sound. In my view though, using a single number as a cutoff may need further scientific validation based on large population data. Also worth noting that different disease or metabolic states may influence bone markers and skew the results. It will be interesting to see what this thread compiles.
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I used Forteo, a similar PTH analog to Tymlos. For those who are interested, here are my btm numbers, no baseline unfortunately but the trend is telling:
Forteo 13mo: CTX not measured, P1Np 450
17mo: CTX 910, P1NP 200
22mo: CTX 800, P1NP 137
I use a simple CTX/P1NP ratio myself. The ratio clearly shifted over time. I had a good outcome and moved from osteoporosis to osteopenia.

@mayblin Great!! I am glad you were willing/able to share your scores, while using Forteo to help others. Your ratios are similar at 220 & 196. I think you will find the data trending over time with the Tymlos versus the Forteo in the video interesting.

Per the video, well-established large clinical trials and data were used to establish the 150 or greater benchmark. The theory and explanation provided in the video sure seems to be logical enough to casually monitor the trending at home, based on the bone markers that are ordered by your doctor (ot for some, paid for privately). The video also discusses Forteo, as well as Evenity.

My wife has been on Tymlos for several months. Her ratio has improved a lot.

Before Tymlos: P1NP 93, CTX 889, ratio 105 (not good)
After four months: P1NP 310, CTX 1700, ratio 182 (good!)

CTX can go up, but if P1NP goes up by a bigger percentage, that's good.

@njx58 Fantastic!! Thank you for sharing. Happy to see your wife's results are right in line with mine! I was a little worried, because I have had to reduce my dose, due to side effects, for three of the 6 weeks I've been on Tymlos. Best wishes!!

@cathyf31, i really appreciate your perspective and sharing that link! It’s a great video for visualizing how these markers move in tandem.

In looking at Dr. Doug’s framework, it seems the '150' benchmark is a clinical rule of thumb he’s developed himself, as the ACTIVE study he quoted (the Phase 3 trial for abaloparatide/Tymlos) actually handles the data a bit differently. I did a deep dive into that paper a while back when I was trying to figure out an 'optimal' ratio for myself, and I noticed the BTM results in the study were actually based on a smaller subset of the group - about 450 people, or 20% of the total ACTIVE trial - 189 for abaloparatide and 227 for teriparatide.

The study itself didn’t land on a single 'cut-off' number; the authors used a pretty complex calculation called an 'uncoupling index' to look at trends. It would be fantastic if Dr. Doug eventually publishes his own database findings on that 150 threshold; having peer-reviewed data on a simple ratio like that would be such a helpful addition to the field!

In my own experience, I’ve found that a single number can be a little tricky. I’ve known a number of people with ratios well above 150 who didn't see BMD gains as expected, so reality seems a bit 'messier' than the graphs might suggest.

I’m still a huge advocate for BTM testing, though - it’s been a game changer for my own treatment. This forum is such a good place to compare notes on what our markers are telling us. I usually take info from social media with a grain of salt... and my own personal deep dives with a whole jar of salt!

@mayblin Agree 100%. The mentioned benchmark can only be taken as a rule of thumb. I think the video did a fairly good job with stating that the ratio is not a scientific-based/contolled study, but simply him crunching data numbers based on other controlled studies. For the average patient, though, I think it's an easy calculation and way to monitor (rather than waiting 12 months for a DEXA comparison)....and to encouage discussions with health providers. Paying potentially insane amonuts of money (and in cases like mine where side effects are quite challenging), it would be a shame to be completely blindsided a year or two down the road that the treatment was not effective. The ratio may possibly give a blurry glimpse of what to expect. Regardless of what data is, or is not published in the future, we all know a one size-fits-all is not practical. It is doubtful that any treatment will ever be able to claim 100% guarantee re: expected gains. There are way too many variables in everybody's world to hope for that. Best wishes to you!

@cathyf31 I will add my numbers to this as it is interesting to compare.

P1NP 22 mcg/L
CTX 108 pg/mL EZ
Ratio = 203.7 🙂

History: T-scores in the -2.x range. 18 months of alendronate (aka Fosamax) followed by 6 months of HRT. Doing LIFTMOR type weight lifting and impact exercises for about 4-6 months. Low supplement of MK4 and MK7 until these tests.

My recollection is that in another video Dr. Doug Lucas mentions in passing that he is less confident of his rule-of-thumb ratio when BTM numbers are quite low, as mine are. But I did not keep a record of which video that was, so cannot provide a link. I am hoping that as the alendronate wears off that my bone turnover will go up. Thanks to @mayblin for comments on a private message while I was still doing some research.

Hi all, I'm also tracking my BTM's especially as I get closer to coming off Tymlos. I am 15 1/2 months into my treatment, and also want to note that at the 8th-month mark I dropped to a lesser dose of 60mcg's because the side effects were making my life miserable. I am small (5 ft, 115lbs). I still have some of the random limb pain but it is not debilitating. Also, I began HRT (0.05mg patch estradiol), 200 mg progesterone and vag estradiol) 4 months before beginning Tymlos, unfortunately I didn't think to get pre-HRT BTM's...that would have been interesting!
Pre-Tymlos: (on HRT for 4 mos)
P1NP=67
CTX=486
Ratio 137

At 8 months (and after going for ~week on reduced dose):
P1NP=358
CTX=1142
Ratio 314

At 12 months
P1NP=289
CTX=1026
Ratio 280

Had DEXA done at the 12 month mark and results showed I was no longer in osetoporosis but it had pulled me back into osteopenia. (DEXA checked for accuracy..done on same machine, etc...) The Tymlos was especially effective on my spine (as they say it does) where I made the most gains:
Spine: up 64%, from -3.3 to -1.2
RTH up 20% from -2.5 to -2.0
RFN up 14% from -2.8 to -2.4
LTH up 24% from -2.9 to -2.2
LFN up 26% from -3.1 to -2.3

My Endo wants me on ReClast no later than a month off Tymlos to lock in the gains. I am very worried about the ReClast side effects and am hunting around for alternative solutions to the inevitable rebound that is expected when coming off the Tymlos. I plan to start supplementing with K2 (Mk4 and MK7) but want to have an osteocalcin array done before to see what my baseline cOC/ucOC ratio is before doing that., and will get another set of BTM's done at the same time to see where I am. Not sure how effective the K2 will be while still on Tymlos but we'll see. I am also looking at bumping my Lactoferrin and collagen intake, trying to engineer a 'soft landing' if you will!! If I can get my CTX down enough I want to see if he will agree to a reduced dose of the ReClast, maybe at more frequent intervals. Given my reaction to the Tymlos I am terrified of what my reaction to a full 5 mg infusion of the ReClast might be and I just really don't want to do that. But I also really don't want to give up these gains! I'll keep you posted. Good luck everybody!

@michieg
You might want to double check the %gain, as those are based on BMD values, not Tscores.

That’s a great response to Tymlos + HRT! Are you planning to follow up with both Reclast & HRT after Tymlos? What dose of MK-4 or MK-7 are you thinking of adding?

@mayblin Sorry, I was just doing a basic %change in my T-score.... difference/baseline X 100 ? Didn't mean to imply anything else.
I DM'd you privately on the rest...