Calcaneus bone mineral density is lower among men and women with lower physical performance

Fracture risk is influenced by both bone strength and by falls. Measures of physical function and performance are predictors of falls. However, the in terrelationships among bone mineral density (BMD), regular physical activit y, and measures of physical performance are not well known. We studied 447 community-dwelling Japanese people aged 40 years and over (96 men and 351 w omen) to examine the association of calcaneus BMD with measures of physical performance (grip strength, walking speed, chair stand, and functional rea ch) and regular physical activity. Calcaneus BMD decreased with age by appr oximately 25% in men and 42% in women. Measures of physical performance dec reased with age by approximately 30% in both genders, however, performance on the chair stand test declined by approximately 60%. There were only mini mal differences in performance measures and calcaneus BMD between people wi th and those without regular physical activity in both genders, and most di fferences were not significant. However, there were significant BMD increas es of 3-6% per standard deviation (SD) increase in all performance measures for women and a 7% increase in BMD per SD increase in grip strength for me n, after adjusting for age. These associations remained after additional ad justment for body mass index and regular physical activity. These findings suggest that bone density and physical function decline markedly in both me n and women with age, and that low BMD and poor function tend to occur toge ther, which would increase fracture risk more than either risk factor alone .