Early identification of children predisposed to low peak bone mass and osteoporosis later in life

The amount of bone that is gained during adolescence is the main contributo r to peak bone mass, which, in turn, is a major determinant of osteoporosis and fracture risk in the elderly. We examined whether computed tomography measurements for the density and the volume of bone in the axial and the ap pendicular skeletons could be tracked through puberty in 40 healthy white c hildren (20 girls and 29 boys). Longitudinal measurements of the cross-sect ional area and cancellous hone density of the vertebral bodies and the cros s-sectional and cortical bone areas of the femurs at the beginning of puber ty accounted for 62-92% of the variations seen at sexual maturity; on avera ge, 3 yr later. When baseline values for these bone traits were divided int o quartiles, a linear relation across Tanner stages of sexual development w as observed for each quartile in both girls and boys. The regression lines differed among quartiles for each trait, paralleled each other, and did not overlap. Thus, we are now in a position to identify those children who are genetically prone to develop low values for peak bone mass and toward whom osteoporosis prevention trials should be geared.