Peripheral Quantitative Computed Tomography (pQCT), Broad Band Ultrasound Attenuation (BUA) and Speed of Sound (SOS) in a population of normal females aged from 8 to 20 years

Purpose. To evaluate, in a population of young healthy females aged from 8 to 20 years the bone mass peak (or density), the normal ranges versus age and menarche-age using two methods: pQCT (peripheral Quantitative Computed Tomography) and ultrasound absorptiometry. Material and methods. From 1998 to 2000 selective measurement of Bone Mineral Density (BMD) of trabecular bone at the ultradistal radius using pQCT, BUA (Broad Band Attenuation) and SOS (Speed of Sound) was carried out on 426 healthy females (aged from 8 to 20 years) in north Italy. BMD was measured using a single photon miniaturized tomographic scanner in the ultradistal radius, SOS and BUA were measured at the same time, using a water bath device obtaining parametric bidimensional images of BUA and SOS. The population studied refers to normal females free of bone metabolism alteration, in pre and post-pubertal status. Results. A normal range of BMD, BUA and SOS versus age and menarche age were established. A linear correlation was found between BUA and BMD measured with pQCT. SOS does not show any correlation with BMD. The pre-puberty and the post-puberty groups show statistically significative differences between SOS, BUA and BMD. We found the peak bone density (measured with pQCT) in the trabecular bone at the ultradistal radius at 15 years of age (mean menarche age of 10 years).The same position of me peak was found for BUA, for SOS the situation is not well defined. The analytical fitting of the data highlights a polynomial correlation of BMD vs. age, SOS vs. age, BUA vs. age. Conclusions. It appears that sexual growth influences the position of peak bone density. The results obtained show a statistically significant correlation between BUA and BMD and age, the menarche-age and the period of exposure of bone tissue to oestrogen. After all, pQCT and ultrasound are useful techniques to evaluate bone density and structure also in a growing population. The results of this study show that it is possible to use bidimensional quantitative ultrasound devices in clinical practice also in young populations taking in account age and sexual development.