Clinical utility of serum bone turnover markers in postmenopausal osteoporosis therapy monitoring: a systematic review.

Objectives Serum bone turnover markers (sBTM) are used in clinical practice for patients undergoing postmenopausal osteoporosis therapy. The aim of this study was to systematically analyze the literature on the ability of sBTM to monitor therapy, focusing on the following 5 objectives: (1) pretreatment values and treatment choice; (2) short-term changes and clinical response; (3) sBTM effect on persistence to therapy; (4) sBTM ability to predict fracture risk after withdrawal of therapy; and (5) the prediction of serious adverse effects. Methods A systematic search on Medline completed manually was performed until November 2010 and was limited to postmenopausal osteoporosis and marketed therapies. Results Following the PRISMA statement for systematic reviews, 48 studies were selected. Baseline sBTM levels were not able to predict fracture risk reduction with either treatment. There was more evidence for the prediction of fracture risk reduction with bone formation sBTM including PINP than with sCTX. Most of the studies found correlations between sBTM and bone mineral density (BMD) changes under antiresorptive therapies, although inconsistently. The only published study on the impact of sBTM on persistence to therapy showed negative results. There was no evidence that sBTM allow the prediction of adverse effects, especially osteonecrosis of the jaw. Conclusions sBTM reflect the skeletal effects of anti-osteoporotic treatments. Pretreatment values are not recommended for selecting therapy. Short-term changes are significantly correlated with BMD variation, but there is no published evidence that they predict benefit on fracture risk at the individual level.