Infante C, Hurtado J, Salazar G, Pollastri A, Aguirre E, Vío F
Facultad de Ciencias, Universidad de Chile, Santiago.
Eur J Clin Nutr. 1991 Mar;45(3):121-9.
A validation study of the dose-to-mother deuterium dilution method to measure breast-milk intake has been carried out on ten infants from a Nutrition Recovery Centre in Santiago, Chile. Formula milk labelled with exponentially decreasing doses of deuterium oxide represented milk from a 'pseudo mother' of these exclusively bottle-fed infants. Unlabelled formula represented milk from other sources. Deuterium levels in the infants' body water were measured on saliva samples by mass spectroscopy. The data were fitted in a two-compartment steady-state model of the mother-child system to estimate the flow of labelled water from the 'mother' to the infant and the 'mother' and infant's water elimination constants. A dose-to-child experiment was also carried out on each infant to determine the deuterium dilution space and total daily water intake. Total and labelled water flows from deuterium dilution were used to calculate total, labelled and unlabelled formula milk intakes which were compared to the same quantities measured by bottle weighing. Water elimination constants calculated from the dose-to-mother experiments underestimated by 17 per cent the initially set mother constant and overestimated by 21 per cent the infant constants calculated from the dose-to-child experiments. Rate constants, however, have little effect on the estimated water flows so that there was good agreement between values from deuterium dilution and from direct weighing. Mean (SD) total formula, labelled formula and unlabelled formula intakes were 865 (129) g/d, 417 (74) g/d and 448 (106) g/d, respectively, when measured by deuterium dilution, compared with 856 (116) g/d, 414 (71) g/d and 441 (68) g/d when measured by direct weighing. The mean per cent differences were 1.1 per cent, 0.7 per cent and 1.6 per cent and the mean absolute differences for individuals, 4.3 (1.9) per cent, 4.8 (3.1) per cent and 9.7 (6.6) per cent, respectively.
对智利圣地亚哥一家营养康复中心的10名婴儿进行了一项验证研究，以评估母亲氘稀释法测量母乳摄入量的效果。用氧化氘剂量呈指数递减的配方奶代表这些纯人工喂养婴儿的“假母亲”的乳汁。未标记的配方奶代表其他来源的乳汁。通过质谱法测量婴儿唾液样本中的氘水平。将数据拟合到母婴系统的两室稳态模型中，以估计标记水从“母亲”到婴儿的流量以及“母亲”和婴儿的水消除常数。还对每个婴儿进行了儿童剂量实验，以确定氘稀释空间和每日总水摄入量。利用氘稀释法得到的总水流和标记水流来计算总配方奶、标记配方奶和未标记配方奶的摄入量，并与通过奶瓶称重测量的相同量进行比较。从母亲剂量实验计算出的水消除常数比最初设定的母亲常数低17%，比从儿童剂量实验计算出的婴儿常数高21%。然而，速率常数对估计的水流影响很小，因此氘稀释法和直接称重法得到的值之间有很好的一致性。通过氘稀释法测量时，平均（标准差）总配方奶、标记配方奶和未标记配方奶摄入量分别为865（129）g/天、417（74）g/天和448（106）g/天，而通过直接称重法测量时分别为856（116）g/天、414（71）g/天和441（68）g/天。平均百分比差异分别为1.1%、0.7%和1.6%，个体的平均绝对差异分别为4.3（1.9）%、4.8（3.1）%和9.7（6.6）%。
