Monitoring BMD Provides a Useful Index of Efficacy for Osteoporosis Therapy

The role of bone mineral density (BMD) measurement to monitor efficacy of osteoporosis treatment is controversial. In a registry-based Canadian cohort study, 6629 women (mean baseline age, 64) were identified who had baseline BMD tests, began osteoporosis treatment (bisphosphonates in 85%), and had repeat BMD testing a mean 4.5 years later. By BMD criteria, most participants (57%) had osteoporosis while 18% had BMD T scores between −2.0 and −2.5 at baseline.

At the total hip, 30% of women had significant increases in BMD (>0.03 g/cm²), 51% remained stable, and 19% had significant decreases. Risk for major osteoporotic fracture over 5 years was 7.2% in women with stable BMD, 5.9% in those with gains in BMD, and 10.1% among those who experienc…