Cortical bone loss at the tibia in postmenopausal women with osteoporosis is associated with incident non-vertebral fractures: Results of a randomized controlled ancillary study of HORIZON

• Published in: Maturitas 2014-03, Vol.77 (3), p.287-293
• Main Authors: Popp, A.W, Buffat, H, Cavelti, A, Windolf, M, Perrelet, R, Senn, C, Lippuner, K
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Biological and medical sciences; Bone Density - drug effects; Bone Density Conservation Agents - pharmacology; Bone Density Conservation Agents - therapeutic use; Diphosphonates - pharmacology; Diphosphonates - therapeutic use; Diseases of the osteoarticular system; Female; Fracture risk; Fractures, Bone - etiology; Fractures, Bone - prevention & control; Gynecology. Andrology. Obstetrics; Humans; Imidazoles - pharmacology; Imidazoles - therapeutic use; Incidence; Internal Medicine; Medical sciences; Obstetrics and Gynecology; Osteoporosis, Postmenopausal - complications; Osteoporosis, Postmenopausal - drug therapy; Osteoporosis, Postmenopausal - metabolism; Osteoporosis. Osteomalacia. Paget disease; Post-dose symptoms; Postmenopausal osteoporosis; Puberal and climacteric disorders (male and female); Tibia - metabolism; Tibial BMD; Zoledronate
• ISSN: 0378-5122; 1873-4111
• DOI: 10.1016/j.maturitas.2013.12.013

Abstract Background In postmenopausal women, yearly intravenous zoledronate (ZOL) compared to placebo (PLB) significantly increased bone mineral density (BMD) at lumbar spine (LS), femoral neck (FN), and total hip (TH) and decreased fracture risk. The effects of ZOL on BMD at the tibial epiphysis (T-EPI) and diaphysis (T-DIA) are unknown. Methods A randomized controlled ancillary study of the HORIZON trial was conducted at the Department of Osteoporosis of the University Hospital of Berne, Switzerland. Women with ≥1 follow-up DXA measurement who had received ≥1 dose of either ZOL ( n = 55) or PLB ( n = 55) were included. BMD was measured at LS, FN, TH, T-EPI, and T-DIA at baseline, 6, 12, 24, and 36 months. Morphometric vertebral fractures were assessed. Incident clinical fractures were recorded as adverse events. Results Baseline characteristics were comparable with those in HORIZON and between groups. After 36 months, BMD was significantly higher in women treated with ZOL vs. PLB at LS, FN, TH, and T-EPI (+7.6%, +3.7%, +5.6%, and +5.5%, respectively, p < 0.01 for all) but not T-DIA (+1.1%). The number of patients with ≥1 incident non-vertebral or morphometric fracture did not differ between groups (9 ZOL/11 PLB). Mean changes in BMD did not differ between groups with and without incident fracture, except that women with an incident non-vertebral fracture had significantly higher bone loss at predominantly cortical T-DIA ( p = 0.005). Conclusion ZOL was significantly superior to PLB at T-EPI but not at T-DIA. Women with an incident non-vertebral fracture experienced bone loss at T-DIA.