ABSTRACT
Evidence suggests that sports activity can induce site-specific changes in bone mineral content (BMC) in athletes. Therefore, the first purpose of this study was to create a standard value for BMC (SV<sub>BMC</sub>) that is independent of body size and physical exercise effect. The second purpose was to examine usefulness for the SV<sub>BMC</sub>. In creating the SV<sub>BMC</sub>, we recruited non-customer subjects who engaged in regular exercise but did not have site-specific changes to their bony structure. We studied 285 females (34.0±6.5 years) that were currently active, free from hormone treatment, and were not taking medication for any condition. Furthermore, all female subjects reported having a normal menstrual cycle. Bone area (BA), BMC and areal bone mineral density (aBMD) were measured by dual-energy X-ray absorption. Measurements of almost the complete skeleton, with the exception of the head, were taken (herein referred to as sub-total). This included scans of the entire spinal column, all 12 ribs, pelvis, full legs and arms. An allometry formula that relates BMC and BA was applied to determine the SV<sub>BMC</sub>. To exclude the effect of body size, calculations were determined using the perpendicular distance from the data of each individual to that determined by allometry regression. Finally, the mean and standard deviation of the distance were converted into T-scores. In examination of reliability for the SV<sub>BMC</sub>, we calculated the SV<sub>BMC</sub> for three customer females who engaged in regular exercise. We found a significantly positive relationship between SV<sub>BMC</sub> and weight/BMI. This correlation was weaker than the relationship between SV<sub>BMC</sub> and BMC, as expected, or the relationship between SV<sub>BMC</sub> and aBMD, with the exception of SV<sub>BMC</sub> in the pelvis. In conclusion, this study suggests that SV<sub>BMC</sub> is less affected by body size than by BMC or aBMD and the SV<sub>BMC</sub> was provided highly useful in case study.