Effect van anti-osteoporosemedicatie op het ontstaan van wervelfracturen

- In the early nineties of the last century, increase in bone mineral density (BMD) was usually the primary endpoint in studies observing the effect of anti-osteoporotic medication. Recently, several large studies have been published with the number of new vertebral deformities as the primary endpoint. This should be preferred, since fractures are generally associated with clinical signs and symptoms, while changes in BMD are not. In all these studies of the effects of alendronate, risedronate, raloxiphen and calcitonin in postmenopausal women with osteoporosis there was a striking discrepancy between a small increase in BMD of the lumbar spine, varying from +2 tot +8, and a much larger reduction in the number of patients with new vertebral fractures: -36 to -49. This difference could be related to an effect on bone quality, an independent effect on bone resorption, or to technical limitations of BMD measurements that underestimate true effects of antiresorptive therapy. The number of patients needing to be treated to prevent one fracture depended on background risk and on the effectiveness of the therapy.