[Can biochemical markers for bone density be recommended as diagnostic and prognostic tools in osteoporosis?]

Biochemical markers of bone metabolism have potential clinical value in osteoporosis, rheumatic diseases, metabolic bone diseases, and skeletal metastasis. The markers are measured in serum or urine and reflect bone synthesis or bone resorption. Knowledge of the markers' analytical and biological variation, sensitivity, and specificity is necessary to make use of these measurements. This article gives a review of the new bone markers available today: osteocalcin, bone alkaline phosphatase, procollagen peptides, pyridinolines, and telopeptides. Bone markers are clearly useful in research and in epidemiological studies, but routine clinical use is still controversial. We discuss the consequences of making use of bone markers in the diagnostics of osteoporosis, as a prognostic factor of bone loss or fractures, or to monitor therapy. We conclude that we still lack sufficient knowledge to justify use in clinical practice.