Comparison of quantitative ultrasound measurements in calcaneus with DXA and SXA at other skeletal sites: A population-based study on 280 children aged 11-16 years

We performed ultrasound measurements (QUS) of the calcaneus in a population -based setting on 280 healthy children, aged 11-16 years, from a small urba n area in southern Sweden. The results are compared with dual-energy X-ray absorptiometry (DXA) measurements in the total body, the lumbar spine and t he hip, as well as single-energy X-ray absorptiometry (SXA) of the forearm. Normative data and correlations between the three different techniques wer e determined. We found significant correlations between QUS and age (r = 0. 34- 0.54), height (r = 0.13-0.56) and weight (r = 0.30-0.60), and between Q US and bone mineral density (BMD) measurements (r = 0.44-0.70). Boys increa sed all their bone mineral variables with age, whereas girls showed a decre asing trend from age 15 years. QUS had a significantly higher increase in s tandardized value with age than Ward's triangle BMD, but a significantly lo wer increase in standardized value with age than distal radius (cortical si te) BMD. At other BMD sites we did not find any significant differences com pared with QUS regarding changes with age. The measurements obtained by QUS , DXA and SXA, respectively, were divided into quartiles. Of all subjects i n the lowest quartile for QUS measurements, only 34-50% were also in the lo west quartiles for DXA and SXA measurements. In conclusion, QUS measurement s of the calcaneus in children show similar results as for adult regarding the correlation with DXA and SXA; they also have a significant correlation with anthropometric data. QUS did not identify the same individuals with lo w bone mass as the X-ray techniques.