Real-world comparative effectiveness of denosumab versus zoledronic acid on bone mineral density changes in postmenopausal osteoporosis: An IPTW cohort study.

BackgroundTo compare the real-world effectiveness and safety of denosumab versus zoledronic acid in postmenopausal osteoporosis (PMO) and characterize baseline fracture risk profiles.MethodsThis retrospective cohort study included 250 PMO patients treated with denosumab (n = 148) or zoledronic acid (n = 102). Inverse probability of treatment weighting (IPTW) was applied to balance baseline covariates. The primary endpoint was 12-month change in lumbar spine bone mineral density (BMD). Fracture risk status was descriptively analyzed.ResultsThe cohort was predominantly high-risk (98.4%). IPTW achieved adequate covariate balance. At 12 months, denosumab showed greater increases in lumbar spine BMD than zoledronic acid (6.09% vs. 4.82%; difference 1.27%, 95% CI: 0.474-2.067; P = 0.002), with consistent findings at the hip. Most adverse events were comparable between groups; however, acute phase reaction occurred significantly less frequently with denosumab, while no differences were observed in hypocalcemia or renal events.ConclusionDenosumab was associated with greater BMD gains than zoledronic acid over 12 months, with broadly comparable safety in a real-world PMO population. These findings are limited to short-term BMD outcomes.