Brunton J A, Bayley H S, Atkinson S A
Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada.
Am J Clin Nutr. 1993 Dec;58(6):839-45. doi: 10.1093/ajcn/58.6.839.
Precision and validity of dual-energy x-ray absorptiometry (DXA) for analysis of whole-body composition in infants were assessed by 1) scanning piglets in triplicate to calculate CVs, and 2) comparing DXA estimates with chemical analysis of whole carcass. The mean CVs for all DXA measures in small piglets and large piglets were < 2.5%, except for fat mass, which were 6.3% and 3.5%, respectively. In large piglets DXA provided reasonable estimates of chemical analysis for bone mineral content (BMC), lean body mass, and fat mass, but only for lean body mass in small piglets. DXA overestimated fat by twofold and underestimated BMC by a third in small piglets. Scans of prematurely born infants (n = 17) at term and at 3, 6, and 12 mo corrected age demonstrated that changes in BMC, lean body mass, and fat mass can be quantitated by DXA. However, further refinement of DXA technology is necessary before reliable measures of BMC and fat mass in small infants are attainable.
通过以下方式评估双能X线吸收法（DXA）分析婴儿全身成分的精密度和有效性：1）对仔猪进行三次扫描以计算变异系数（CV），以及2）将DXA估计值与整个胴体的化学分析结果进行比较。小猪和大猪所有DXA测量值的平均CV均<2.5%，脂肪量除外，其CV分别为6.3%和3.5%。在大猪中，DXA对骨矿物质含量（BMC）、去脂体重和脂肪量的化学分析提供了合理估计，但在小猪中仅对去脂体重提供了合理估计。在小猪中，DXA高估脂肪两倍，低估BMC三分之一。对17名早产儿在足月时以及矫正年龄3个月、6个月和12个月时的扫描表明，BMC、去脂体重和脂肪量的变化可用DXA进行定量。然而，在获得小婴儿BMC和脂肪量的可靠测量值之前，DXA技术需要进一步改进。
