Bone turnover markers

Osteoporosis is the most prevalent metabolic bone disease and its impact is expected to rise throughout the world with the aging of the population (Harvey et al., 2010). It is defined as a disease characterized by low bone mass and microarchitectural deterioration of bone tissue, leading to enhanced bone fragility and consequent increase in fracture risk (Peck, 1993). Low bone mass, measured as bone mineral density (BMD), is asymptomatic and its important outcome is fracture, which is associated with significant morbidity and mortality. This is especially true for hip fracture (Kanis and Johnell, 2005). Therefore, the clinical management focus in osteoporosis is to prevent or reduce the risk of fracture and ensure adequate response to therapy. The identification of the patients to be treated relies on bone mineral density (BMD) measurement, most commonly using dual-energy X-ray absorptiometry (DXA) (Kanis et al., 2008), and fracture risk assessment based on BMD and other risk factors (age, gender, prior fractures, parental hip fracture history, body mass index, ethnicity, smoking, alcohol use, glucocorticoid use, rheumatoid arthritis, and secondary osteoporosis) using risk calculators such as FRAX® (Kanis et al., 2011).