Davies P S, Wells J C
Infant and Child Nutrition Group, Dunn Nutrition Unit, Cambridge, UK.
Eur J Clin Nutr. 1994 Jul;48(7):490-5.
Total body water can be calculated using stable isotopes by two alternative approaches known as the plateau method and the back extrapolation method. These methods treat the isotopic data in different ways and consequently do not necessarily produce identical values for total body water. Total body water was therefore calculated using both methods using two different tracers, 2H and 18O.
A cohort of infants was studied at three ages in the first year of life, and the two methods and two tracers compared at each age.
The plateau method was found to produce values for total body water greater than those obtained by the back extrapolation method at all three ages using both isotopes (P < 0.01 in all cases).
This difference is due to the different time points at which total body water is calculated. Back extrapolation values correspond more closely to values of total body water obtained by alternative techniques.
全身水含量可以通过稳定同位素，采用两种不同的方法来计算，即平台法和反向外推法。这些方法处理同位素数据的方式不同，因此全身水含量的计算结果不一定相同。因此，我们使用两种不同的示踪剂2H和18O，通过这两种方法来计算全身水含量。
对一组婴儿在出生后第一年的三个年龄段进行研究，并在每个年龄段比较两种方法和两种示踪剂。
发现在所有三个年龄段，使用两种同位素时，平台法计算出的全身水含量值均高于反向外推法得出的值（所有情况P<0.01）。
这种差异是由于计算全身水含量的时间点不同所致。反向外推值与通过其他技术获得的全身水含量值更为接近。
