Bone Microstructure Changes due to Once-/Twice-Weekly Teriparatide Administration: A Report of Five Cases Using High-Resolution Peripheral Quantitative Computed Tomography.

This study was conducted with the aim of presenting cases in which high-resolution peripheral quantitative computed tomography (HR-pQCT) was used to investigate changes in bone microstructure due to once-weekly/twice-weekly administration of teriparatide (TPTD). Of osteoporosis patients who participated in a non-inferiority trial (TWICE study: once-weekly vs twice-weekly TPTD) with lumbar bone mineral density (BMD) as the primary endpoint, five cases scanned by HR-pQCT before TPTD administration were analyzed. Two cases were given once-weekly TPTD, three were given twice-weekly TPD, and HR-pQCT was repeated after 48 weeks. A sufficient anabolic effect of once-weekly/twice-weekly TPTD on the trabecular and cortical bone at the tibia was obtained. In addition, the average change in cortical porosity (Ct.Po) was only 0.3% in the tibia and 0.2% in the radius. These findings indicate that once-weekly and twice-weekly TPTD can be expected to improve bone microstructure, and the increase in Ct.Po may be suppressed.