Loss of bone density and lean body mass after hip fracture

Few studies of bone loss have assessed the amount of loss directly after a hip fracture. The present prospective study was conducted to determine chan ges in bone mineral density (BMD) and muscle mass shortly after fracture an d through 1 year to assess short-term loss and related factors. The setting was two acute care teaching hospitals in Baltimore, Maryland, and subjects were 205 community-dwelling women with a new fracture of the proximal femu r between 1992 and 1995. Bone density of the nonfractured hip and whole-bod y and body composition were measured by dual-energy X-ray absorptiometry at 3 and 10 days and 2, 6 and 12 months after admission. Mean BMD of the femo ral neck was 0.546 +/- 0.007 g/cm(2) at baseline. Average loss of femoral n eck BMD from baseline was 2.1% at 2 months, 2.5% at 6 months and 4.6% at 12 months. The average loss of BMD in the intertrochanteric region was 2.1% a t 12 months. Total lean body mass decreased by 6% while fat mass increased by 3.6% by 1 year after the fracture. These findings indicate that signific ant loss in BMD and lean body mass occur shortly after hip fracture while b ody fat increases. Continued loss was evident throughout the 1 year of foll ow-up. This loss of both bone density and muscle mass may lead to new fract ures.