Age-related response to 12-month romosozumab in treatment-naïve Japanese women aged 55-100 years with primary osteoporosis.

Abstract

This study aimed to investigate the age-related bone mineral density (BMD) response to romosozumab. A prospective cohort study was conducted on 221 treatment-naïve women aged 55-100 years with primary osteoporosis who initiated a 12-month romosozumab therapy. Percent changes in lumbar spine (LS), total hip (TH), and femoral neck (FN) BMD and bone turnover markers were assessed at 6 and 12 months. Associations between age and treatment efficacy were analyzed using multivariate regression, adjusting for potential confounders. Sensitivity analyses were conducted according to the baseline 25-hydroxyvitamin D (25OHD) status (<20 vs. ≥20 ng/mL). Restricted cubic spline curves were applied to assess the potential non-linear associations between age and the BMD response, adjusting for the same covariates. Multivariate regression showed that younger age is independently associated with higher percent changes in LS BMD at 6 (regression coefficient [β], -0.31; 95 % confidence interval [CI], -0.45 to -0.18) and 12 months (β, -0.19; 95 % CI, -0.36 to -0.02). Sensitivity analyses confirmed the association between age and percent gains in the LS BMD at 6 months but not at 12 months. No evidence of non-linearity was found at 6 (p for non-linearity = 0.874) and 12 months (p for non-linearity = 0.686). No significant associations were observed for TH or FN BMD or the bone turnover markers. An inverse linear relationship was observed between age and percent change of the LS BMD at 6 months; however, the relationship was not robust at 12 months.