Endocrine Abstracts

Osteoporosis is a chronic condition requiring long-term treatment; sequential treatment regimens with different agents represents an option aimed to increase bone mineral density (BMD) and then to maintain it. The loss of BMD occurring after withdrawal of teriparatide (TPT) can be prevented by bisphosphonates (BPs). Among BPs, data about the efficacy of zoledronic acid (ZOL) after TPT treatment are scanty. Here, we contribute to this topic providing data derived from the real-life setting of the third level centre Istituto Ortopedico Galeazzi in Milan. Twenty-two severe osteoporotic fractured patients [4 males, 18 postmenopausal females; aged 74.4 (65.8, 78.9) years, median, IQ range; BMI 26.1±4.5 kg/m², mean±SD] were treated with subcutaneous daily 20 microg TPT (according the Italian AIFA 79 note) for 24 months followed by two intravenous infusions of 5 mg ZOL, the first one at < 6 months from TPT withdrawal, the second one 12 months from the first infusion. Eight patients were smokers; 7 patients were treated with chronic steroid therapy ( >5 mg prednisone daily). Clinical and biochemical parameters were collected in all patients. BMD at lumbar and femur sites were measured by dual x-ray absorptiometry and recorded as T-scores. All patients experienced at least one vertebral fracture (3.0, 2.0-2.3). Mean lumbar T-score [-3.09±1.18] increased after TPT treatment (-2.45±1.33,P=0.002 by ANOVA) and the increase was consolidated by ZOL treatment (-2.17±1.35,P=0.0002 vs basal condition by ANOVA). Mean lumbar T-score increase was 21% of the basal T-score after TPT and further 11% after TPT+ZOL. Median neck T-score [-2.70 (-3.30, -2.08)] was not affected by TPT [-2.50 (-3.00, -1.88)] as well as by TPT+ZOL treatment [-2.50 (-3.20, -1.78);P=0.157 by ANOVA]. Median total hip T-score [-2.40 (-2.90, -1.56)] increased after TPT+ZOL treatment [-1.75 (-2.48, -1.28);P=0.049 by ANOVA]. Any patient experienced incident fractures during TPT treatment, while 1 patient reported a femur fracture and one patient a non-vertebral non-femur fracture during ZOL treatment. During the sequential TPT+ZOL treatment serum calcium and phosphate levels did not show significant changes, while plasma PTH levels decreased during TPT and increased during ZOL treatment. Serum total ALP and β-CTX levels increased during TPT and decreases during ZOL treatment. Serum 25hydroxyvitamin D were constantly >20 ng/ml in all patients. In conclusion, our data from real-life management of severe osteoporotic patients showed that the sequential treatment TPT+ZOL is effective in increasing and maintaining lumbar and hip BMDs.