Differential influence of physical activity on lumbar spine and femoral neck bone mineral density in the elderly population

This study investigates the relationship between lifetime physical activity and bane mineral density (BMD) at Various sites in 129 healthy men and wom en aged 72.1 +/- 6.5 years. BMD was measured by dual energy x-ray absorptio metry, and physical activity was assessed by using the QUANTAP system (Quan tification de l'Activity Physique), a standardized and structured computer- assisted interview tool designed to assess lifetime physical activity. Line ar regression models controlling for age, gender, height, body mass, lean m ass, and smoking habits were performed. Higher levels of sporting activity during youth were associated with greater lumbar spine BMD (p < .001). Simi larly, femoral neck BMD was greatest in subjects who reported regularly tak ing part in sports over the previous 20 years (p < .05) and during their wh ole life-time (p < 0.05). Sporting activity at the time of bone mass develo pment increases subsequent lumbar spine BMD, and more recent sporting activ ity contributes to the preservation of femoral neck BMD. These results sugg est that physical activity has a differential influence on BMD at different sites and at different ages, possibly related to the processes of bone con struction and bone aging taking place at the time.