Zinc improves Denosumab and eldecalcitol efficacy for bone mineral density in patients with hypozincemia.

Introduction: We aimed to investigate the effects of zinc deficiency and zinc medication in osteoporosis patients undergoing denosumab (DMAb).

Materials and methods: This retrospective study was conducted at a single hospital. The participants were female osteoporosis patients visiting between April 2019 and April 2020. All patients were treated with DMAb and eldecalcitol and recommended zinc-rich food. Based on zinc medication and serum zinc levels at the 12th month of dietary guidance, patients were categorized into the following four groups: hypozincemia with zinc medication, latent zinc deficiency with zinc medication, without zinc medication, and control without zinc medication. Longitudinal serum zinc concentrations, bone mineral density (BMD), and occurrence of fractures were measured. We investigated the factors influencing no response to DMAb and eldecalcitol treatment.

Results: Among the 145 patients followed up for 24 months, dietary guidance did not change the serum zinc concentration; however, zinc medication significantly increased these levels. The hypozincemia group did not show a significant BMD increase in the lumbar spine and femoral neck after DMAb and eldecalcitol treatment during dietary guidance; however, zinc medication increased these to the same levels as the other groups. In multivariate analyses, hypozincemia and thyroid disease were identified as the factors affecting no response. While 28.2% of patients with latent zinc deficiency without zinc medication suffered fractures, no fractures occurred in hypozincemia patients with zinc medication.

Conclusion: Hypozincemia may reduce the efficacy of DMAb and eldecalcitol in increasing BMD and fracture prevention.