Markers of bone turnover Overview and clinical significance

Parameters assessing bone turnover may provide additional information in the diagnosis of osteoporosis, adding to bone mineral density, clinical data and routine laboratory. Parameters of bone formation include procollagen type 1 N-terminal propeptide (P1NP), bone-specific alkaline phosphatase (bALP) and osteocalcin (OC). Parameters of bone resorption are pyridinoline (PYD) and desoxy pyridinoline (DPD), N-terminal collagen type I-telopeptide (NTX) and C-terminal collagen type I-telopeptide (CTX), beta-crosslaps (beta-CTX), tartrate-resistant acid phosphatase (TRAP5b) as well as cathepsin K. The clinical utility lies especially in the monitoring of bone turnover after initiation of osteoporosis therapy to evaluate treatment efficacy and in the monitoring of patient compliance, while the decision to commence treatment cannot be based solely on bone turnover markers alone. In haemato-oncology, high bone turnover markers, especially high parameters of bone resorption, are associated with a higher risk for skeletal-related events.