Personalizing denosumab therapy in postmenopausal Indian women with osteoporosis: predictive role of bone turnover markers and body mass index in determining dosing interval.

This prospective study evaluated whether bone turnover markers (BTMs) and body mass index (BMI) can guide individualized denosumab dosing in postmenopausal Indian women with osteoporosis. Lower baseline β-CTX and BMI were independently associated with safe deferral of denosumab beyond 6 months, without increased fracture risk. These findings support a personalized, phenotype-based approach to denosumab therapy in low-turnover populations. PURPOSE: To evaluate whether baseline bone turnover markers (BTMs) and body mass index (BMI) can predict the safety and feasibility of extending the dosing interval of denosumab beyond six months in postmenopausal Indian women with osteoporosis.

methodsIn this prospective observational study, 56 postmenopausal women with DXA-confirmed osteoporosis were initiated on denosumab (60 mg subcutaneously).None of the participants had received prior anti-resorptive therapies. Several participants were on vitamin D supplementation, consistent with their high baseline serum 25-hydroxyvitamin D levels. Serum ß-CTX levels were measured at 6 months, guiding the timing of subsequent injections. Participants were classified into two groups: standard (dose at 6 months) and delayed (dose deferred beyond 6 months if ß-CTX <300 pg/mL). Baseline BTMs, BMI, and fracture outcomes were analysed. Multivariate logistic regression was used to identify predictors of delayed dosing.

resultsTwenty-eight women received delayed injections (median interval: 9.5 months). Compared to the standard group, the delayed group had significantly lower baseline ß-CTX levels (497 vs. 794 pg/mL; p < 0.001) and lower BMI (23.29 ± 2.77 vs. 25.59 ± 3.03 kg/m²; p = 0.005). Multivariate analysis showed both lower baseline ß-CTX (OR: 0.99; 95% CI: 0.98-1.00; p = 0.027) and lower BMI (OR: 0.60; 95% CI: 0.40-0.89; p = 0.012) independently predicted delayed denosumab administration. No new vertebral fractures were observed in either group during follow-up.

conclusionsLower baseline bone turnover and lower BMI may help identify postmenopausal Indian women in whom denosumab dosing can be safely deferred beyond six months. These findings are preliminary and do not establish long-term safety or efficacy; further studies with extended follow-up are needed before adopting extended dosing intervals in clinical practice.