Treatment With Zoledronate Subsequent to Denosumab in Osteoporosis 2 (ZOLARMAB2)

The aims of ZOLARMAB2 are fourfold. First, the investigators want to investigate if multiple infusions of zoledronate can prevent the rebound activation of bone turnover and the subsequent bone loss in patients previously treated with denosumab and if there is difference between infusing zoledronate at fixed time-points after the last injection of denosumab or when bone turnover is increased. Second, the investigators want to investigate if bone loss will resume after controlling the rebound activation of bone turnover during the first year after denosumab discontinuation and if this can be prevented by yearly infusions of zoledronate. Third, the investigators want to investigate the underlying pathophysiological mechanisms by investigating biochemical markers, osteoclast and osteoblast activation signals in the bone and bone marrow, and the pool of preosteoclasts/mature osteoclasts before and after treatment with zoledronate. Fourth, the investigators want to investigate the effect of denosumab discontinuation on muscle mass and muscle strength and on insulin sensitivity.