Synergistic Efficacy of Calcitriol Combined with Denosumab versus Calcitriol Alone in Postmenopausal Osteoporosis: A Retrospective Cohort Study.

OBJECTIVE

To evaluate the efficacy and safety of calcitriol combined with denosumab versus calcitriol alone in postmenopausal osteoporosis (PMO).

METHODS

In this retrospective cohort study, 306 postmenopausal women with PMO were divided into two groups: an intervention group (n = 144) receiving calcitriol, denosumab, and calcium/vitamin D3, and a control group (n = 162) receiving calcitriol and calcium/vitamin D3 only, over 12 months. Outcomes included bone mineral density (BMD), bone turnover markers, calcium-phosphate homeostasis, patient-reported outcomes (VAS, ODI, BI), and adverse events.

RESULTS

The intervention cohort demonstrated more pronounced enhancements in BMD measured at the lumbar spine, femoral neck, and total hip (all P < 0.05). Additionally, there was a more marked reduction in bone turnover markers, namely β-C-terminal telopeptide of type I collagen (β-CTX), Tartrate-resistant acid phosphatase 5b (TRACP-5b), Procollagen type I N-terminal propeptide (P1NP), and Bone Gla Protein (BGP) (P < 0.05). Superior regulation of calcium-phosphate homeostasis-reflected by Parathyroid Hormone (PTH) and 25-hydroxyvitamin D [25(OH)D] levels-was also observed in this group (P < 0.05). Patient-reported outcomes (VAS, ODI, BI) also improved more markedly (P < 0.05). The incidence of adverse events was low and comparable between groups, with no serious events reported.

CONCLUSION

Calcitriol combined with denosumab synergistically enhances BMD, suppresses bone turnover, improves functional outcomes, and maintains a favorable safety profile in PMO, representing a promising therapeutic strategy.