C-Telopeptide, A Surrogate Biomarker of Bone Remodeling--Specifically, Osteoclast Cell Activity
When it comes to monitoring response to therapy, whether positive or negative, waiting two years for the next insurance approved bone mineral density (DXA) test results wastes a lot of valuable time. Especially when we are worrying about osteoporotic-related fracture risk. We want patients back on the road to better bone health ASAP!
Instead of waiting for the next DXA test, it is much more efficient to use lab biomarkers every few months to assess effectiveness of therapy. For example, if a patient tests low for a nutrient such as vitamin D, it makes sense to retest several months later to see if the D level is rising with the addition of supplemental vitamin D. If a patient tests abnormally high for a biomarker of inflammation, such as high-sensitivity C-reactive protein (hsCRP), it is prudent to obtain a repeat test several months later to see if what they are doing therapeutically (such as diet changes and supplements such as curcumin, fish oil, and vitamin E) is having its intended effect.
The same holds true for assessing bone loss. The biomarker C-terminal telopeptide (CTX) can be used as a surrogate marker to measure bone turnover, and specifically, bone resorption by the osteoclasts. When osteoclastic activity becomes hyper-aggressive, this leads to excessive bone loss. Therapy is directed at reducing osteoclast resorptive activity which will preserve bone.
We want to know, as soon as possible, if what we are doing is working. Waiting two years for the next bone density (DXA) results to assess response to therapy is inefficient...and excruciatingly stressful for the patient.
By using CTX as a surrogate biomarker of osteoclastic activity, and thus bone loss, we can see if its level upon repeat testing after 6 months is reflective of decreased osteoclasitic activity. If this follow-up CTX test is at least 100 points lower after initiating diet and lifestyle changes and adding a supplemental nutrition program (including such things as OsteoNaturals' OsteoStim), then we know we are winning the war against osteoporosis. If we don't see a substantial reduction in CTX, then it might be prudent to select another form of therapy, or at least tweak what we are currently doing.