We found that vitamin D insufficiency is associated with increased BF and decreased height but not changes in peak bone mass.

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Purpose:To determine normative reference values for vertebral trabecular bone density (TBD) obtained by using quantitative computed tomography (CT) in healthy white children, teenagers, and young adults of both sexes. Materials and Methods:The data presented in this HIPAA-compliant study are a compilation of data from multiple investigations on the determinants of bone acquisition in healthy children conducted at this institution from 1992 to 2006. The institutional review board for clinical investigations approved the protocols for each of these studies, and written informed consent was provided by all parents and/or participants. Quantitative CT measurements of TBD (in milligrams per cubic centimeter) were obtained at the first, second, and third lumbar vertebrae in 1222 healthy white male and female subjects aged 5-21 years (mean age for male subjects, 15.1 years Ϯ 3.6 [standard deviation]; range, 5.6 -21.9 years; mean age for female subjects, 14.2 years Ϯ 3.9; range, 5.7-21.6 years; mean age for both sexes, 14.6 years Ϯ 3.8). Mean and standard deviations for TBD were determined for each age group in 1-year intervals, and Student t tests for unpaired data were performed to compare male subjects with female subjects. Results:TBD increased equally during growth in male and female subjects. Although the percentage increase in TBD was similar for both sexes (23.7% [57 of 241] for male subjects, 22.2% [54 of 243] for female subjects), the rise began and reached peak values at an earlier age in female subjects; increases in TBD occurred from 10 -15 years of age in female subjects, whereas in male subjects, these increases were not observed until age 12 years and were completed at 17 years. Conclusion:This study provides reference standards for quantitative CT bone measurements in children and young adults, which may aid in the diagnosis, prevention, and treatment of pediatric metabolic bone disorders. Note: This copy is for your personal, non-commercial use only. To order presentation-ready copies for distribution to your colleagues or clients, use the Radiology Reprints form at the end of this article.M easurements of bone density during childhood are commonly obtained to assess the deficiencies in bone accumulation associated with a multitude of pediatric disorders. Moreover, the amount of bone that is gained during growth is an important determinant of the risk for osteoporosis later in life (1,2), and available data suggest that the genetic susceptibility to osteoporosis is detectable in childhood (3). Peak bone mass, a major determinant of the future risk of fractures in the elderly, is largely achieved by the end of sexual development (4).Because of its availability, minimal radiation exposure, and relative ease of use, dual-energy x-ray absorptiometry (DXA) is the most commonly employed quantitative radiologic method to assess bone mass at any age (5). The interpretation of DXA bone studies is considerably more challenging in children than in adults. Although reference data and diagnostic algorithms are avai...

Because DXA is a projection technique, anterior–posterior (AP) measurements of the spine include the posterior elements and the vertebral body. This may be a disadvantage because the posterior elements likely contribute little to vertebral fracture resistance. This study used QCT to quantify the impact of the posterior elements in DXA AP spine measures. We examined 574 subjects (294 females and 280 males), age 6–25 yr, with DXA and QCT. QCT measures were calculated for the cancellous bone region and for the vertebral body including and excluding the posterior elements. DXA data were analyzed for the entire L3 vertebra and for a 10-mm slice corresponding to the QCT scan region. BMC and BMD were determined and compared using Pearson's correlation. The posterior elements accounted for 51.4 ± 4.2% of the total BMC, with a significant difference between males (49.9 ± 4.0%) and females (52.8 ± 3.9%, p < 0.001). This percentage increased with age in younger subjects of both sexes (p < 0.001) but was relatively consistent after age 17 for males and 16 for females (p > 0.10). DXA areal BMD and QCT volumetric BMD correlated strongly for the whole vertebra including the posterior elements (R = 0.83), with BMC measures showing a stronger relationship (R = 0.93). Relationships were weaker when excluding the posterior elements. We conclude that DXA BMC provides a measure of bone that is most consistent with QCT and that the contribution of the posterior elements is consistent in young subjects after sexual maturity.