Rigo J, Nyamugabo K, Picaud J C, Gerard P, Pieltain C, De Curtis M
Neonatal Unit, University of Liège, Hôpital de la Citadelle, Belgium.
J Pediatr Gastroenterol Nutr. 1998 Aug;27(2):184-90. doi: 10.1097/00005176-199808000-00011.
As previously reported, dual-energy x-ray absorptiometry provides reliable and accurate values for bone mineralization in piglets and infants, but overestimates fat content in small infants. The purpose of the current study was to determine an appropriate equation of correction for fat mass measurement and to establish reference values of body composition of preterm and term neonates.
Fat mass and chemical whole-body fat content were evaluated by dual-energy x-ray absorptiometry in eight piglets with a body weight between 1408 and 5151 g. The results were combined with previous data obtained in 13 piglets, and two correction equations were determined according to fat mass content. Close to birth, 106 healthy appropriate-for-gestational-age preterm and term infants were scanned by dual-energy x-ray absorptiometry to determine bone mineral content, bone area, and fat mass. Fat mass content determined by dual-energy x-ray absorptiometry was corrected using the equations obtained in piglets after which lean body mass was recalculated.
Multivariate analysis showed that dual-energy x-ray absorptiometry body weight was the best predictor of bone mineral content (r2 = 0.94), bone area (r2 = 0.95), lean body mass (r2 = 0.98), and fat mass (r2 = 0.84). Gender was an additional significant independent variable for fat mass and lean body mass. Body weight related curves of percentiles for bone mineral content, bone area, fat mass, and lean body mass, were constructed. In vivo dual-energy x-ray absorptiometry values of fat mass and calcium content estimated from bone mineral content were in accordance with previously reported whole-body carcass reference values in preterm and term neonates.
Normative data of dual-energy x-ray absorptiometry body composition for healthy preterm and term infants are provided and can therefore be used in research and in clinical practice.
如先前报道，双能X线吸收法可为仔猪和婴儿的骨矿化提供可靠且准确的值，但会高估小婴儿的脂肪含量。本研究的目的是确定脂肪量测量的合适校正方程，并建立早产和足月新生儿身体成分的参考值。
采用双能X线吸收法对8头体重在1408至5151克之间的仔猪进行脂肪量和化学全身体脂含量评估。将结果与先前在13头仔猪中获得的数据相结合，并根据脂肪量含量确定了两个校正方程。临近出生时，对106名健康的适于胎龄的早产和足月婴儿进行双能X线吸收法扫描，以确定骨矿物质含量、骨面积和脂肪量。使用在仔猪中获得的方程对双能X线吸收法测定的脂肪量含量进行校正，然后重新计算瘦体重。
多变量分析表明，双能X线吸收法测得的体重是骨矿物质含量（r2 = 0.94）、骨面积（r2 = 0.95）、瘦体重（r2 = 0.98）和脂肪量（r2 = 0.84）的最佳预测指标。性别是脂肪量和瘦体重的另一个重要独立变量。构建了骨矿物质含量、骨面积、脂肪量和瘦体重百分位数与体重相关的曲线。根据骨矿物质含量估算的脂肪量和钙含量的体内双能X线吸收法值与先前报道的早产和足月新生儿全身胴体参考值一致。
提供了健康早产和足月婴儿双能X线吸收法身体成分的标准数据，因此可用于研究和临床实践。
