Biochemical Markers of Bone Turnover and Response of Bone Mineral Density to Intervention in Early Postmenopausal Women: An Experience in a Clinical Laboratory (Endocrinology and Metabolism‪)‬

To reduce accelerated bone loss in early postmenopause (1-5) and to minimize the risk of fracture, a variety of antiresorptive treatments (e.g., calcium, calcitonin, estrogens, and bisphosphonates) have been used. A positive response to therapy can be assessed by the measurement of bone mineral density (BMD),[1] but a statistically significant change usually requires 1 or more years because of the imprecision of the BMD measurement (6,7). This limitation may be avoided by use of biochemical markers of bone turnover in the serum or urine, which can show the effects of intervention sooner. In addition, bone turnover markers provide a more representative indicator of overall skeletal bone loss than the results obtained by measuring rates of change in BMD at a single skeletal site. The ability to determine a positive response to therapy in advance of BMD facilitates the clinical decision to alter a patient's regimen or dosage of medication to achieve the desired antiresorptive effect. Assays for several biochemical markers of bone turnover are commercially available, but their relative sensitivities are unclear. In this study, we investigated, in a clinical laboratory setting, biochemical markers of bone turnover for monitoring of several types of intervention for early postmenopausal bone loss and evaluated whether the responsiveness of biochemical markers is related to the response in BMD. Materials and Methods