Molecular Biomarkers & Diagnosis

Biochemical Bone Markers as Predictors of Excessive Bone Turnover Suppression during Osteoporosis Treatment with Bisphosphonates

Abstract

Branka Kovacev-Zavisic, Tijana Icin, Jovanka Novakovic-Paro, Milica Medic-Stojanoska, Milena Mitrovic, Dragana Tomic – Naglic, Ivana Bajkin, Nikola Curic, Milan Dolga and Nemanja Kovacev

Background: It should be decided before the introduction of osteoporosis therapy whether to start the therapy with the inhibitor of resorption or with the stimulator for bone formation. The decision should also be made during the therapy with antiresorptives regarding the appropriate time to stop the therapy and start the therapy with stimulators for bone formation. Assuming that normal or reduced levels of bone metabolism is limiting factor for initiation of antiresorptive therapy, and thereafter the appropriate parameter for the decision to stop antiresorptive therapy and start with stimulators of bone metabolism, we believe that the determination of bone markers should be compulsory and an integral part of the diagnostic procedure. The aim of this study was to determine whether antiresorptive therapy leads to satisfactory or excessive suppression of bone metabolic activity depending on the initial values of bone markers. Methods: We performed a prospective longitudinal study of 178 postmenopausal women with osteoporosis. We were following the values of osteocalcin, beta-crosslaps before the introduction of bisphosphonates therapy and after three months during therapy. Results: The results speak in favor of decreased bone resorption during antiresorptive therapy and that the value of bone markers during antiresorptive therapy may be predicted depending on the initial values. If we add osteocalcin and βCTx values before the therapy to the equation: -0.041*OC-0.003*βCTx+2.983, patients having result >0, will have excessive suppression of bone resorption during the therapy. If we add values to the equation: -0.054*OC-0.001*βCTx+2.075, patients having result >0, will have excessive suppression of entire bone remodeling during the therapy. Conclusion: We suggest that osteoporosis patients who are predicted to have excessive suppression of entire bone remodeling during bisphosphonate therapy, should be mainly treated with stimulators for bone formation or possibly with medications with dual mode of action.