A ultrassonometria óssea e o risco de fraturas em idosas

Reference data for ultrasound bone characteristics in Hungarian children aged 7-19 years

Backround: Osteoporosis is a common disease and physical activity (PA) has a favourable influence on bone status.

AIM

To establish normative data for calcaneal quantitative ultrasound (QUS) bone characteristics in children and to analyse the relationships between PA, anthropometric and bone parameters.

SUBJECTS AND METHODS

Hungarian children aged 7-19 (n = 2674; 1325 girls, 1349 boys) provided PA, anthropometric and bone data. QUS parameters were registered with Sonost3000 densitometer (speed of sound: SOS, m/s; broadband ultrasound attenuation: BUA, dB/MHz; bone quantity index (BQI = αSOS + βBUA). Reference centiles of QUS parameters were constructed by LMS method. Multivariate linear regression models were used to analyse the relationships.

RESULTS

QUS bone parameters increased with age. There were no gender differences, except in 11- and 19-year-old children, where boys showed higher values. SOS (1497.15 ± 15.72 vs 1494.05 ± 14.81 m/s) and BQI (65.31 ± 16.71 vs 62.26 ± 15.78) were higher in athletic children. The regression model revealed significant relations between SOS and age, relative muscle mass and PA; BUA correlated with gender, morphological age, BMI, relative muscle mass and PA.

CONCLUSIONS

Changes in the bone parameters among 7-19-year-old Hungarian children depended on age, anthropometric dimensions and the level of PA. The normative data could be used for monitoring QUS bone parameters in children, leading to more effective interventions for healthy bones.

Correlation between ultrasound velocity and densitometry in fresh and demineralized cortical bone

OBJECTIVE:

To compare ultrasound propagation velocity with densitometry in the diaphyseal compact cortical bone of whole sheep metatarsals.

METHODS:

The transverse ultrasound velocity and bone mineral density of 5-cm-long diaphyseal bone segments were first measured. The bone segments were then divided into four groups of 15 segments each and demineralized in an aqueous 0.5 N hydrochloric acid solution for 6, 12, 24 or 36 hours. All measurements were repeated after demineralization for each time duration and the values measured before and after demineralization were compared.

RESULTS:

Ultrasound velocity and bone mineral density decreased with demineralization time, and most differences in the pre- and post-demineralization values within each group and between groups were significant: A moderate correlation coefficient (r=0.75956) together with a moderate agreement was determined between both post-demineralization parameters, detected by the Bland-Altman method.

CONCLUSION:

We conclude that both ultrasound velocity and bone mineral density decrease as a result of demineralization, thus indicating that bone mineral content is of great importance for maintaining the acoustic parameters of cortical bone, as observed for cancellous bone. Ultrasound velocity can be used to evaluate both compact cortical bone quality and bone mineral density.