Ritz P, Cole T J, Couet C, Coward W A
Dunn Nutrition Centre, Medical Research Council, Cambridge, United Kingdom.
Am J Physiol. 1996 Jan;270(1 Pt 1):E164-9. doi: 10.1152/ajpendo.1996.270.1.E164.
Accuracy and precision of the the doubly labeled water (DLW) measurements of energy expenditure are commonly estimated with models that do not account for 2H and 18O natural abundance variation. A new and simple treatment that completes the ratio-product model is derived in the present study. It uses both linear regression of multipoint data with time and information on within-subject 2H and 18O natural abundance variation. Use of this treatment is demonstrated in a group of seven subjects in whom 2H and 18O natural abundance variation was assessed by collecting predose samples for 6-8 days before dosing. In this set of 16 measurements, the precision (coefficient of variation) of individual DLW estimates of CO2 production was 4.90 +/- 2.14%, of which 3.23 +/- 1.20% arose from natural abundance variation.
双标记水（DLW）能量消耗测量的准确性和精密度通常使用未考虑2H和18O自然丰度变化的模型进行估计。本研究推导了一种完善比率乘积模型的新的简单处理方法。它既使用了多点数据随时间的线性回归，也使用了个体内2H和18O自然丰度变化的信息。在一组7名受试者中展示了这种处理方法的应用，这些受试者在给药前通过收集6 - 8天的给药前样本评估了2H和18O自然丰度变化。在这组16次测量中，个体DLW二氧化碳产生量估计值的精密度（变异系数）为4.90±2.14%，其中3.23±1.20%源于自然丰度变化。
