Background Biochemical bone turnover markers (BTM) provide dynamic information on skeletal status and can complement information regarding bone mineral density (BMD) assessed by DEXA . In the past, BTM were limited to use in research but their use in clinical practice is increasing. In our clinic, we measure the bone formation marker serum N-terminal of propeptide type 1 collagen (P1NP) and bone resorption marker serum c-terminal telopeptide (CTX). They can measure response to treatment with bisphosphonates showing suppression of bone turnover and also predict early response to anabolic agents which lead to increased bone turnover. They can allow earlier monitoring than DEXA where changes may not be seen for up to 2 years. Measurement of BTM may improve compliance with anti-osteoporotic medication although this has not been conclusively confirmed in clinical trials .
Objectives To assess whether measurement of BTM influences clinical decision making in a teaching hospital metabolic bone disease clinic.
Methods We obtained the BTM results for 2 consecutive months from the metabolic bone disease clinic and obtained all available prior and subsequent results. The patients’ case records were reviewed to assess whether these results had any effect on clinical decision making
Results Results were obtained for 57 patients. The majority had osteoporosis (n=55), other diagnoses were Paget’s disease and hypophosphataemic rickets.
Conclusions Measurement of BTM provides valuable information in a metabolic bone disease clinic. In patients receiving IV zoledronate they ensured that further IV zoledronate was delayed if BTM were over suppressed. In patients receiving teriperatide they confirmed a metabolic response to this expensive therapy at an early stage. They led to a change in treatment in a further patient, no indication to change treatment in another patient and may also play a role in decisions regarding “drug holidays” from bisphosphonates.
Delmas, P.D., Eastell, R., Garnero, P., Seibel, M.J., and Stepan, J., The use of biochemical markers of bone turnover in osteoporosis. Committee of Scientific Advisors of the International Osteoporosis Foundation. Osteoporos Int, 2000; 11 Suppl 6: p. S2-17.
Delmas, P.D., Vrijens, B., Eastell, R., Roux, C., Pols, H.A., Ringe, J.D., et al., Effect of monitoring bone turnover markers on persistence with risedronate treatment of postmenopausal osteoporosis. J Clin Endocrinol Metab, 2007; 92(4): p. 1296-304.
Disclosure of Interest None Declared