[Measurement of bone mineral density is unnecessary for monitoring of bisphosphonate treatment].

A monitoring period in osteoporosis treatment should be considered in accordance with the efficacy of medicine as well as the precision of monitoring tool, because a significant bone gain should be larger than the precision error of the measurement. Regarding bisphosphonate treatment in osteoporosis, 2-5 years'period is required to detect a significant change in bone mineral density (BMD) using dual-energy x-ray absorptiometry. Furthermore, the degree of increase in BMD by bisphosphonate treatment cannot account for the degree of reduction in the risk of fracture. It therefore makes no sense to determine how much BMD increases during the treatment.