ORF34-05 - Menopausal Hormone Therapy Is Associated with a 69% Lower Risk of Low Bone Mineral Density in Postmenopausal Women: A Retrospective Cohort Study

Objective: To determine whether menopausal hormone therapy (MHT) use is independently associated with bone mineral density (BMD) in postmenopausal women, in the context of contemporary clinical practice. For many years, eligible postmenopausal women have avoided menopausal hormone therapy largely due to the presence of regulatory black-box warnings, which have recently been removed or reframed, prompting renewed evaluation of its clinical benefits.

Methods: We performed a retrospective cohort study including 387 postmenopausal women who underwent dual-energy X-ray absorptiometry (DXA) between 2021 and 2025. All DXA measurements were acquired using a single densitometry system (Hologic Horizon A) and performed by the same certified bone densitometry technician and certified clinical densitometrist, minimizing inter-operator variability. Participants were classified as MHT users (n = 129; 33.3%) or non-users (n = 258; 66.7%). Bone status was defined according to WHO criteria. Low BMD was defined as osteopenia or osteoporosis. Group differences were assessed using Student’s t-test and χ² test. Multivariable logistic regression was used to identify independent predictors of low BMD, adjusting for age, years since menopause, body mass index, vitamin D levels, smoking status, and metabolic comorbidities.

Results: Low BMD was identified in 186 women (48.1%). Compared with non-users, MHT users demonstrated significantly higher BMD at clinically relevant skeletal sites, including the lumbar spine (T-score −0.62 ± 0.85 vs −1.02 ± 0.81; p < 0.001) and total hip (−0.32 ± 0.82 vs −0.81 ± 0.78; p < 0.001). Groups were comparable in age, vitamin D levels, and years since menopause (all p > 0.3). In the adjusted regression model, MHT use was independently associated with 69% lower odds of low BMD (OR 0.31; 95% CI 0.19–0.50). Increasing years since menopause (OR 1.09 per year; 95% CI 1.02–1.16) and smoking (OR 2.25; 95% CI 1.01–5.02) were associated with higher risk, whereas higher vitamin D levels were protective (OR 0.96; 95% CI 0.93–0.99).

Conclusions: In this real-world cohort, menopausal hormone therapy was strongly and independently associated with higher bone mineral density and a substantially lower risk of low BMD. These findings suggest that, beyond symptom control, MHT may represent an underutilized strategy for bone preservation in appropriately selected postmenopausal women, particularly within the early postmenopausal window.