Randomized controlled trial of daily teriparatide, weekly high-dose teriparatide, or bisphosphonate in patients with postmenopausal osteoporosis: The TERABIT study.

PURPOSE: The effects of daily teriparatide (20 µg) (D-PTH), weekly high-dose teriparatide (56.5 µg) (W-PTH), or bisphosphonates (BPs) on areal bone mineral density (aBMD), bone turnover markers (BTMs), volumetric BMD (vBMD), microarchitecture, and estimated strength were investigated in postmenopausal osteoporosis patients. METHODS: The study participants were 131 women with a history of fragility fractures. They were randomized to receive D-PTH, W-PTH, or BPs (alendronate or risedronate) for 18 months. Dual-energy X-ray absorptiometry (DXA), BTMs, and high-resolution peripheral quantitative CT (HR-pQCT) parameters were evaluated at baseline and after 6 and 18 months of treatment. The primary endpoint was the change (%) in cortical thickness (Ct.Th) after 18 months' treatment compared with baseline. RESULTS: DXA showed that D-PTH, W-PTH, and BPs increased lumbar spine aBMD (+12.0%, +8.5%, and +6.8%) and total hip aBMD (+3.0%, +2.1%, and +3.0%), but D-PTH and W-PTH decreased 1/3 radius aBMD (-4.1%, -3.0%, -1.4%) after 18 months. On HR-pQCT, D-PTH increased trabecular vBMD (Tb.vBMD) at the distal radius and tibia after 18 months (+6.4%, +3.7%) compared with the BPs group, decreased cortical volumetric tissue mineral density (Ct.vTMD) (-1.8%, -0.9%) compared with the other groups, increased Ct.Th (+1.3%, +3.9%), and increased failure load (FL) (+4.7%, +4.4%). W-PTH increased Tb.vBMD (+5.3%, +1.9%), maintained Ct.vTMD (-0.7%, +0.2%) compared with D-PTH, increased Ct.Th (+0.6%, +3.6%), and increased FL (+4.9%, +4.5%). The BPs increased Tb.vBMD only in the radius (+2.0%, +0.2%), maintained Ct.vTMD (-0.6%, +0.3%), increased Ct.Th (+0.5%, +3.4%), and increased FL (+3.9%, +2.8%). CONCLUSIONS: D-PTH and W-PTH comparably increased Ct.Th, the primary endpoint. D-PTH had a strong effect on trabecular bone. Although D-PTH decreased Ct.vTMD, it increased Ct.Th and total bone strength. W-PTH had a moderate effect on trabecular bone, maintained Ct.vTMD, and increased Ct.Th and total bone strength to the same extent as D-PTH.

Adjuvant endocrine therapy effects on bone mineral density and microstructure in women with breast cancer.

INTRODUCTION: Although aromatase inhibitors (AIs) are typical drugs for cancer treatment-induced bone loss, their effects on the bone microstructure remain unclear. In this study, we evaluated changes in the bone mineral density (BMD) and bone microstructure associated with AI treatment using high-resolution peripheral quantitative computed tomography (HR-pQCT) in patients with early breast cancer. MATERIALS AND METHODS: This prospective, single-arm, observational study included non-osteoporotic, postmenopausal women with hormone receptor-positive breast cancer. Patients underwent dual-energy X-ray absorptiometry (DXA), HR-pQCT, and tartrate-resistant acid phosphatase-5b (TRACP-5b) or procollagen type-I N-terminal propeptide measurements at baseline and 6 and 12 months after AI therapy. The primary endpoint was changes in the total volumetric BMD (Tt.vBMD), trabecular vBMD (Tb.vBMD), and cortical vBMD (Ct.vBMD) longitudinally at the distal radius and tibia. RESULTS: Twenty women were included (median age 57.5 years; range 55-72 years). At 12 months, HR-pQCT indicated a significant decrease in the Tt.vBMD (median distal radius - 5.3%, p < 0.01; distal tibia - 3.2%, p < 0.01), Tb.vBMD (- 3.2%, p < 0.01; - 1.0%, p < 0.05, respectively), and Ct.vBMD (- 3.2%, p < 0.01; - 2.7%, p < 0.01, respectively). Estimated bone strength was also significantly decreased. The DXA BMD value in the total hip (p < 0.01) and femoral neck (p = 0.03), but not in the lumbar spine, was significantly decreased. The TRACP-5b levels was significantly negatively associated with changes in the Tt.vBMD in both the distal radius and tibia (r =  - 0.53, r =  - 0.47, respectively) CONCLUSION: Postmenopausal women who received AIs for early breast cancer experienced significant trabecular and cortical bone deterioration and a decrease in estimated bone strength within only 1 year.