The purpose of this study was to examine the effects of anthropometric measures, including body height, body weight, body mass index (BMI), fat mass (FM), and lean body mass (LBM), on quantitative ultrasound (QUS) parameters of calcaneus in 358 Japanese university women. Ultrasonic bone densitometer (Achilles, Lunar corp.) was utilized to measure broadband ultrasound attenuation (BUA), speed of sound (SOS), and stiffness index (SI) of the right calcaneus. The average of SI in this study showed a slight lower value (84, 3±12.1, mean±SD) compared with that in age-matched university women as previously reported. The contradictive finding may suggest the need for a large-scale further investigation on SI in young women. Correlation analysis revealed that both BUA and SI are significantly correlated with all anthropometric measures. However SOS had only weak correlation with LBM. In consideration of the high colinearities of body weight and BMI with FM and LBM, the multiple liner regression analysis was conducted with BUA, SOS, and SI as dependent variables. Body height, FM, and LBM were then entered to a forward stepwise regression model. The analysis proved that the significant predictor of BUA, SOS, and SI is LBM. It also suggested BUA to be stronger correlated with LBM than the other QUS parameters, SOS and SI. In conclusion, our re sults support the view that QUS parameters appear to be influenced by anthropometric measures, especially by LBM in Japanese university women. It is conceivable that an increase in skeletal mus cle mass chiefly induced by physical exercise contributes to the improvement of bone mass as measured by QUS in young women.
