Eldecalcitol reduces the risk of severe vertebral fractures and improves the health-related quality of life in patients with osteoporosis.

Eldecalcitol reduces the risk of vertebral fractures in comparison to alfacalcidol in osteoporotic patients under vitamin D repletion. The aim of this study was to evaluate the effects of eldecalcitol on the spinal location of incident vertebral fractures, the severity of the fractures, and the changes in health-related quality of life (HRQOL) compared with those of alfacalcidol. The post hoc analysis has been performed on the data from the three-year, double-blind, randomized, head-to-head clinical trial of eldecalcitol versus alfacalcidol conducted in Japan. A total of 1054 patients were enrolled and randomized to take 0.75 μg eldecalcitol or 1.0 μg alfacalcidol daily for 3 years. The incidence of vertebral fractures was re-evaluated based on the location on the spine (upper T4-T10; lower T11-L4). The severity of vertebral fractures was determined by the semi-quantitative method, and the change in HRQOL was analyzed by using the Medical Outcomes Study Short Form 36-item questionnaire. The incidence of vertebral fracture at the lower spine was less in the eldecalcitol group than in the alfacalcidol group (p = 0.029). The incidence of severe vertebral fracture (Grade 3) was 3.8 % in the eldecalcitol group and 6.7 % in the alfacalcidol group, demonstrated a significant difference between the 2 groups (p = 0.036). Both eldecalcitol and alfacalcidol improved HRQOL in osteoporotic patients. Although no significant differences in each HRQOL scores were observed between eldecalcitol and alfacalcidol during the observational period, overall improvement from baseline of HRQOL scores were clearly observed in the eldecalcitol group. In conclusion, the incidences of lower spinal vertebral fractures and severe vertebral fractures were reduced further by eldecalcitol compared to alfacalcidol in the 3-year clinical trial. Daily treatment with eldecalcitol is effective in improving HRQOL, possibly owing to the reduced risk of lower spinal vertebral fractures and/or severe vertebral fractures.