Postural sway, the tendency to sway even while standing still, is an independent risk factor for bone fractures in postmenopausal women, according to research published in Journal of Bone and Mineral Research
. This sway has been associated with falls, a risk factor for fractures, but the role of postural sway as an independent fracture risk factor has been unknown before now.
Researchers from the University of Eastern Finland and Kuopio University Hospital found that women with the highest postural sway had a fracture risk that was twice as high as women with the lowest postural sway.
"Our aim was to investigate the association between high postural sway and fractures. In addition, we wanted to study the combined effect of high postural sway and low bone mineral density on fracture risk," first author Sarang Qazi, early stage researcher in the Kuopio Musculoskeletal Research Unit of the University of Eastern Finland, said in a statement
Qazi and colleagues utilized the OSTPRE (Kuopio Osteoporosis Risk Factor and Prevention Study) cohort, which consists of 14,220 peri- and postmenopausal women living in Kuopio, Finland. From 1994 to 1997, postural sway was measured in 1568 of the women. The women in the study were followed up for 15 years, after which fracture data was collected.
In addition to women with the highest postural sway having 2 times higher risk for any fracture compared with women with the lowest postural sway, the researchers found that having low bone mineral density in addition to high postural sway resulted in a 4.9 times higher risk of fracture and an 11.8 times higher osteoporotic fracture risk compared with the women who had highest bone density and lowest postural sway.
A secondary outcome of the study was mortality, but the researchers determined that the association between postural sway and mortality was not significant.
“A combination of low bone density and high postural sway poses even higher fracture risk than either factor alone,” the authors concluded. “Postural sway does not predict mortality independently.”
Qazi SL, Sirola J, Kröger H, et al. High postural sway is an independent risk factor for osteoporotic fractures but not for mortality in elderly women. J Bone Miner Res
. 2019;34(5):817-824. doi: 10.1002/jbmr.3664.