Bone turnover markers to monitor oral bisphosphonate therapy

Bisphosphonates are widely used as first-line therapy to slow bone loss and decrease fracture risk in postmenopausal women with osteoporosis. Nonadherence to oral bisphos-phonates diminishes the benefit of reduced bone loss and fracture risk of these medications. Strategies to enhance osteoporosis monitoring and adherence to therapy are crucial to improve outcomes. Dual-energy x-ray absorptiometry (DXA) is the gold standard for monitoring bone mineral density but is slow to detect change after initiation of oral bisphosphonate therapy. Bone turnover markers (BTMs) are by-products released during bone remodeling and are measurable in blood and urine. We review how the rapid change in BTMs can be a useful short-term tool to monitor the effectiveness of oral bisphosphonate therapy, which may ultimately improve adherence to therapy and outcomes.