Broadband ultrasonic attenuation of children and young adults in Japan.

The purpose of this study was to establish broadband ultrasonic attenuation (BUA: dB/MHz) as bone mineral density (BMD) norms for healthy young Japanese and to evaluate the standard values for an ultrasonic bone analyzer (Cuba Clinical, McCue Ultrasonics Ltd., Winchester, England), which facilitates BMD measurement without exposure to radiation. The subjects were 472 healthy young individuals with no endocrine or skeletal disorders, 197 males (mean age 16 y 5 m) and 275 females (mean age 15 y 7 m) aged from 5 to 29 years. BUA was measured at the left calcaneus. The subjects were divided into five age-stratified different age groups of five years intervals. The mean BUA values (dB/MHz) obtained were 40.6, 60.9, 78.0, 90.4 and 86.0 for males, and 41.9, 61.0, 73.4, 68.4 and 70.8 for females in the 5-9, 10-14, 15-19, 20-24 and 25-29 age groups, respectively. A significant positive correlation was observed between BUA and age in both males and females except in the male 25-29 age group and the female 20-24 and 25-29 age groups. A significantly different BUA between males and females was found in the 20-24 and 25-29 age groups (p < 0.001). The BUA values obtained in this study may serve as BMD norms for children and young adults. It might be thought that measuring BUA from childhood through early adulthood made it possible to determine peak values and peak periods of BMD, providing useful information for assessment of growth and development.