Bone resorption and turnover in health and disease.

Excessive bone loss is a common cause of disability and presents a major public health problem in western societies. The most common cause is age-related bone loss and osteoporosis, but other common diseases associated with increased bone resorption include malignant disease, primary hyperparathyroidism, and Paget's disease. Despite the frequency of these disorders and the suffering they cause, their pathophysiology still remains obscure. However, recent advances in techniques in bone cell biology are now providing new insights into the pathogenesis and treatment of diseases associated with increased bone resorption. These advances have been paralleled by improvements in techniques for non-invasive assessment of bone status in patients with the common metabolic bone diseases.