POS1119 A SINGLE DOSE OF ZOLEDRONATE INDUCES MODIFICATIONS OF SERUM VEGF IN OSTEOPOROTIC POSTMENOPAUSAL WOMEN

Abstract

Background: Zoledronate (Zol) is an aminobisphosphonate commonly used to treat osteoporosis and other benign and malignant skeletal diseases. Exposure to bisphosphonates has been previously associated with the risk of osteonecrosis of the jaw (BRONJ), a rare but serious side effect. In cancer patients, the Vascular Endothelial Growth Factor (VEGF) has been advocated to take part to BRONJ pathogenesis via interfering with angiogenesis. No information is currently available on the VEGF concentrations after Zol administration for osteoporosis. Objectives: To explore change of VEGF concentrations after Zol administration in postmenopausal women with osteoporosis. Methods: A total of twenty‐eight postmenopausal women with osteopenia or osteoporosis and at least one prevalent vertebral fracture were recruited and randomized in two groups. Eighteen women received a single i.v. dose of Zol 5 mg, while the other ten served as controls. Serum samples were collected at baseline, after 3 and 30 days, for repeated measurements of VEGF, and measurement of bone turn over markers and 25‐hydroxyvitamin D (25(OH)D). Results: VEGF levels increased significantly after 3 days in women receiving Zol; then levels decreased after 30 days compared with VEGF concentrations at both day‐3 and baseline (‐18% at day‐30 vs. baseline, p=0.01). 25(OH)D level, a surrogate of vitamin D status, was associated with VEGF change at the end of the study (r=0.29, p=0.028), and this association was maintained also after correcting for age, BMI, time since menopause, femoral neck BMD, osteocalcin, C‐terminal telopeptide of collagen type 1 and baseline levels of VEGF (β=1.7, SE=0.71, p=0.03). Conclusion: Zol administration induced a reduction of circulating VEGF in postmenopausal women treated for osteoporosis, and vitamin D status has been showed to modulate this change. Further studies in this setting of women are needed to define whether VEGF modifications may predict the risk of BRONJ.