The Duration of Denosumab Treatment and the Efficacy of Zoledronate to Preserve Bone Mineral Density After Its Discontinuation

Context: Zoledronate is used to prevent bone loss following denosumab discontinuation but its efficacy differs among studies.Objective: To test if the duration of denosumab treatment affects the efficacy of subsequent zoledronate infusion.Methods: This multicenter, prospective cohort study, conducted at 2 Greek and 1 Dutch bone centers, included 47 postmenopausal women (n=47) who received a single zoledronate infusion 6 months after the last denosumab injection and then were followed for 1 year. Twenty-seven women received 6 denosumab injections (> 6 Group). The main outcome measure was changes in lumbar spine (LS) bone mineral density (BMD).Results: At 12 months LS-BMD values were maintained in the 6 Group (1.0 +/- 0.11 to 0.93 +/- 0.12 g/cm(2), P6 Group (-7.0%). In the whole cohort, the duration of denosumab treatment was negatively correlated with the percentage change of LS-BMD (r(s) = -0.669, P