NIH Grant to Support Study on Possible Fractures from Osteoporosis Drugs

UC San Francisco has received a four-year, $2.4 million National Institutes of Health (NIH) grant for an international study on the potential of femoral fractures from osteoporosis drugs. Researchers hope to clarify which patients are most likely to develop these fractures and help clinicians better target treatments.

Concern has grown among patients and clinicians that bisphosphonates, the most common treatment for osteoporosis, may be related to development of atypical femoral fractures (AFF). In fact, bisphosphonate use has declined more than 30 percent since 2006-2007 because of the uncertainty of risk versus benefits.

However, few large studies have been undertaken to determine bisphosphonate risk, especially with regard to treatment duration and resolution after discontinued use.

“This study will address the key concerns for patients and their health care providers about the safety and efficacy of bisphosphonates,” said principal investigator Douglas Bauer, MD, a professor of Epidemiology & Biostatistics, and clinician-investigator in the Division of General Internal Medicine. “It also will improve our ability to target patients at high risk of fracture while minimizing the risk of serious side effects.”

Bauer’s research team includes the UCSF Department of Radiology and Biomedical Imaging and Bo Abrahamsen, MD, PhD, at the University of Southern Denmark.

The forthcoming study will utilize population-based longitudinal data from Denmark, including centralized health records and nearly two decades of drug exposure information. Digitized radiographs will be reviewed and classified by experts at UCSF, with results merged with Danish health care data, Bauer said.

Bauer and his colleagues expect to describe the rates of radiographically confirmed AFF by age, gender and duration of bisphosphonate use. They also want to determine the independent effect of bisphosphonates by duration of use and cumulative dose on AFF, as well as the impact of other factors like severity of osteoporosis, other medical conditions and other medications. A third goal is to determine if AFF risk declines after discontinuation of bisphosphonates and patient and treatment characteristics that influence risk after discontinuation.