Characteristics of regional bone mineral density and soft tissue composition in patients with atraumatic vertebral fractures.

To clarify the characteristics of total body and regional bone mineral density (BMD) and soft tissue composition in patients with atraumatic vertebral fractures (AVF), we measured total body and regional BMD, lean mass, and fat mass using dual-energy X-ray absorptiometry. Sixty-four women, aged 55-75 years, were divided into two groups: women with AVF (fracture group, n = 30) and women without AVF (nonfracture group, n = 34). Mean BMD of the second to fourth lumbar vertebrae (L2-4BMD), regional BMD, and soft tissue mass were measured. Regional BMD was measured in the head, arms, legs, ribs, thoracic vertebrae, lumbar vertebrae, and pelvis. Lean mass and fat mass of head, arms, legs, and trunk were measured. L2-4BMD, total body BMD, and BMD of the lumbar spine, thoracic spine, and pelvis of the fracture group were significantly lower than those of the nonfracture group (P < 0.001). Total lean and fat mass of the fracture group tended to be lower than that of the nonfracture group. The results suggest that BMD of weight-bearing bones, except for that of the bones of the legs of the fracture group, is significantly lower than that of the nonfracture group, and that total body lean and fat mass may be a predictor for AVF.