Evaluation of bone mineralization in former preterm born children: Phalangeal quantitative ultrasound cannot replace dual-energy X-ray absorptiometry.
Bone Rep 2018;
8:38-45. [PMID:
29955621 PMCID:
PMC6019963 DOI:
10.1016/j.bonr.2018.01.004]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 01/09/2018] [Accepted: 01/17/2018] [Indexed: 01/09/2023] Open
Abstract
Background
Preterm infants are at risk of impaired bone health in later life. Dual-energy X-ray absorptiometry-scan (DXA) is the gold standard to determine bone mineralization. Phalangeal quantitative ultrasound (pQUS) is an alternative technique that is inexpensive, easy to use and radiation-free. The aim of this study was to investigate whether both techniques reveal equivalent results.
Materials and methods
Sixty former preterm infants (31 boys; 29 girls) received a DXA and pQUS at age 9 to 10 years. DXA measured bone mineral content (BMC) and bone mineral density (BMD) for total body and lumbar spine (L1-4), while pQUS measured the amplitude dependent speed of sound (AD-SoS) and bone transit time (BTT) at metacarpals II-IV providing continuous values and Z-scores based on age and sex. Four statistical methods evaluated the association between both techniques: Pearson's correlation coefficients, partial correlation coefficients adjusted for gestational age, height and BMI, Bland-Altman analysis and cross tabulation.
Results
Both techniques showed a statistically significant weak correlation for continuous values as well as Z-scores (0.291–0.462, p < 0.05). Boys had significant and relatively high correlations (0.468–0.585, p < 0.05). In comparison, the correlations for girls were not significant. Correlation coefficients further decreased while calculating the partial correlations. The Bland-Altman plots showed poor agreement. Sensitivity ranged from 33% to 92% and specificity from 16% to 68%. Positive and negative predictive values ranged from 4% to 38% and 82% to 97%, respectively.
Conclusions
We found statistically significant weak correlations and poor agreement between DXA and pQUS measurements. DXA is not equivalent to pQUS and therefore not replaceable by this technique in former preterm born children at the age of 9 to 10 years.
DXA is the golden standard to determine bone mineralization, while Quantitative ultrasound is a radiation-free alternative.
Four statistical tests were used to investigate the equivalence of both methods.
Comparison of results of 60 preterm born children at age 9 to 10 years found poor agreement between both methods.
There was a discrepancy in differentiating the same children with normal or reduced bone mineralization.
Quantitative ultrasound cannot replace the DXA scan for determination of bone mineralization in preterm born children.
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