[Osteoporosis: whom, when and how to treat?].

Osteoporosis is a chronic disease of mass appearance and should be defined as a disease of decreased bone strength rather than a disease of decreased bone mass. Osteoporosis related fractures are of particular interest due to their high burden on the individual and society and also their importance as a target of pharmacological intervention. Bone mineral measurement (BMD), which is an established tool to diagnose osteoporosis (W.H.O., 1994) is not sufficient as a tool for treatment decisions. Currently, assessment of quality of bone is costly, technically demanding and/or invasive. In clinical practice, the W.H.O. recommendation (2007) enables a more advantageous assessment of individual absolute risk of fracture based on BMD and clinical risk factors independent of BMD (sex, age, prevalent fracture, parent fractured hip, use of glucocorticoids, rheumatoid arthritis, secondary osteoporosis, smoking, and excessive alcohol intake). Modern regimens of anticatabolic (antiresorption) therapies not only maintain bone microarchitecture but enable a sufficient bone renewal in majority of patients. However, even with anticatabolic treatments, aging is associated with decrease in new bone formation and mechanical competence of bone. Performance of bone osteoblasts and osteocytes, bone volume and quality and architecture of bone is improved in patients treated with bone anabolic agents. Teriparatide treatment considerably reduces risk of vertebral and nonvertebral fracture, back pain and different aspects of quality of life. However, use of the bone anabolic drugs is limited to 18-24 months. To prevent subsequent increase in risk of fracture, sequential treatments with anabolic and anti-catabolic drugs offer benefits needed for the long-term compliance. In conclusion, selection of drugs with the highest antifracture efficacy should be guided by the underlying mechanisms of osteoporosis, and by expectations of the treatment (safety and efficacy). Anti-catabolic drugs are most appropriate in patients with high bone turnover. Anabolic treatment is indicated in patients with low bone formation in the elderly, in glucocorticoid induced osteoporosis, and where preservation of bone mass and bone architecture by anti-catabolic drugs is not sufficient to efficiently reduce high absolute risk of fracture.