Nearly 1 in 5 women experienced a decrease in total hip BMD during treatment, substantially increasing their risk for fracture.
Treatment-related changes in bone mineral density (BMD) are associated with fracture risk and decreases in BMD during treatment are not uncommon. As such, women taking osteoporosis treatment should have their BMD monitored to determine if their treatment is working. The findings are published in Annals of Internal Medicine.
Osteoporosis, a common cause of fracture, is typically diagnosed based a finding of low bone mineral density (BMD) from dual-energy x-ray absorptiometry (DXA). Screening with DXA is recommended for women aged 65 years or older and in younger women at increased risk for fracture, but there is no consensus on the role of repeated BMD testing after initial evaluation. The practice of repeated BMD testing during pharmacotherapy also remains controversial. Group-level clinical trial data suggest that greater increases in BMD are associated with greater fracture risk reduction, but this may be more difficult to show in clinical practice.
Using data from a comprehensive Canadian registry of more than 6,600 women initiating osteoporosis treatment with two consecutive DXA scans, researchers sought to evaluate repeated BMD testing as an indicator of treatment-related fracture risk reduction. The authors assessed BMD between the first and second scan for each patient. They found that change in total hip BMD after initiation of treatment was an indicator of fracture risk reduction. Most important, the greater the increase in total hip BMD, the lower the fracture risk. In contrast, a decrease in total hip BMD during treatment was not uncommon and occurred in almost 1 in 5 women, which was associated with a substantially increased fracture risk. According to the authors, these data support the use of serial BMD monitoring in clinical practice to determine response to osteoporosis therapy.