Biochemical markers of bone turnover and osteoporosis management

Summary Osteoporosis is defined as a systemic disease characterised by low bone mass and microarchitectural deterioration of bone tissue, both of which are related to abnormalities of bone turnover. Bone mass can be assessed by measuring bone mineral density (BMD) using dual x-ray absorptiometry (DXA), and there is a large body of evidence that low BMD is an important determinant of fracture risk. However, BMD measurement is not the only determinant of fracture risk. Among other determi nants, increased bone resorption evaluated by specific biochemical markers has been shown to be associated with increased risk of hip, spine and non-vertebral fractures independently of BMD. The combination of bone mass measurement and assessment of bone turnover by biochemical markers is thus helpful in the assessment of osteoporotic fracture risk. Repeated measurements of biochemical markers during treatment appear to improve the management of osteoporotic patients. The decrease in bone turnover markers during antiresorptive treatment is re lated to the subsequent increase in BMD. Further, several studies have shown that short-term reductions in bone turnover were associated with a reduction in vertebral and/or non-ver tebral fracture risk in women treated with antiresorptive agents.