Besides bone mineral density (BMD), other bone characteristics can be used to determine fracture risk, according to a new study published in The Lancet Diabetes & Endocrinology.
The results show low BMD is not the only cause of bone fragility, and the majority of older adults who sustain a fragility fracture do not meet the diagnostic criteria for osteoporosis.
“Older women are at particularly high risk of fracture. In fact, the number of women who will experience a fragility fracture in any given year exceeds the number who will experience a first-time stroke, breast cancer, or myocardial infarction combined,” said co-lead author Mary L. Bouxsein, PhD, Director of the Center for Advanced Orthopedic Studies at Beth Israel Deaconess Medical Center, Boston, Massachusetts. “Improved methods to identify those in whom fractures are common but whom standard clinical testing does not identify as high risk would allow us to target treatment to this important group and ultimately reduce fracture burden.”
T scores unreliable
BMD assessed by dual-energy x-ray absorptiometry is the clinical standard for determining fracture risk. The majority of older adults who sustain a fracture, however, have T scores greater than −2.5. Therefore, they do not meet the clinical criteria for osteoporosis, the researchers noted. Importantly, bone fragility is due to low BMD and deterioration in bone structure.
Bouxsein and colleagues assessed whether indices of high-resolution peripheral quantitative computed tomography (CT) were associated with fracture risk independently of femoral neck BMD and the Fracture Risk Assessment Tool (FRAX) score. They assessed 7254 participants, mean baseline age 69 years, in 8 cohorts from the US, France, Switzerland, Canada, and Sweden.
Over a mean follow-up of 4.63 years, 8% of participants met the diagnostic criteria for osteoporosis, yet 11% of participants had incident fractures. Some 633 (86%) participants had femoral neck T scores greater than −2.5.
Samelson EJ, Broe KE, Xu H, et al. Cortical and trabecular bone microarchitecture as an independent predictor of incident fracture risk in older women and men in the Bone Microarchitecture International Consortium (BoMIC): a prospective study. Lancet Diabetes Endocrinol. 2019;7:34-43.