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.