Osteoporosis in Primary Hyperparathyroidism

Investigators will prospectively include 40 postmenopausal women with secondary osteoporosis due to primary hyperparathyroidism who have refused surgery. Participants will be randomized in two groups and treated either with zoledronic acid 5 mg iv once a year or with denosumab 60 mg sc every 6 months. Investigators will compare the effect of both drugs on bone turnover markers and basic laboratory parameters after 3, 12 and 24 months of treatment, and on the bone mineral density after 12 and 24 months of treatment. All participants will take cholecalciferol 800 - 1000 IU daily.