Validation of the doubly labeled water method using off-axis integrated cavity output spectroscopy and isotope ratio mass spectrometry
Validation of the doubly labeled water method using off-axis integrated cavity output spectroscopy and isotope ratio mass spectrometry
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DOI：
10.1152/ajpendo.00241.2017
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发表时间：
2018-02-01
影响因子：
5.1
通讯作者：
Berman, Elena S. F.
中科院分区：
文献类型：
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作者：
Melanson, Edward L.;Swibas, Tracy;Berman, Elena S. F.
当使用双标记水（DLW）方法测量每日总能量消耗（TDEE）时，通常使用同位素比质谱法（IRMS）进行同位素测量。新技术，如离轴集成腔输出光谱（OA-ICOS）提供了标准沃茨和人类尿液样本的可比同位素测量，但与OA-ICOS确定的二氧化碳产量（CO2）的准确性尚未得到证明。我们比较了同时测量CO2使用全室间接量热法（IC）与DLW为基础的测量IRMS和OA-ICOS。17名受试者（10名女性; 22 - 63岁）在IC中连续研究7天。受试者每千克身体总水分消耗0.25 g H-2 O-18（98%APE）和0.14 g（H2O）-H-2（99.8%APE），并在第1天和第8天采集尿样，使用OA-ICOS和IRMS测量平均每日CO2。使用平台和截距法计算CO2。当使用平台法时，与IC相比，OA-ICOS或IRMS测量的CO2没有差异。当使用截距法时，使用OA-ICOS的CO2与IC没有差异，但使用IRMS测量的CO2显著低于IC。OA-ICOS和IRMS测量的CO2的准确度（相似于1-5%）、精密度（相似于8%）、组内相关系数（R = 0.87-90）和均方根误差（30-40升/天）相似。OA-ICOS和IRMS测量CO2的准确度和精度与IC相当。
When the doubly labeled water (DLW) method is used to measure total daily energy expenditure (TDEE), isotope measurements are typically performed using isotope ratio mass spectrometry (IRMS). New technologies, such as off-axis integrated cavity output spectroscopy (OA-ICOS) provide comparable isotopic measurements of standard waters and human urine samples, but the accuracy of carbon dioxide production (CO2) determined with OA-ICOS has not been demonstrated. We compared simultaneous measurement CO2 obtained using whole-room indirect calorimetry (IC) with DLW-based measurements from IRMS and OA-ICOS. Seventeen subjects (10 female; 22 to 63 yr) were studied for 7 consecutive days in the IC. Subjects consumed a dose of 0.25 g H-2 O-18 (98% APE) and 0.14 g (H2O)-H-2 (99.8% APE) per kilogram of total body water, and urine samples were obtained on days 1 and 8 to measure average daily CO2 using OA-ICOS and IRMS. CO2 was calculated using both the plateau and intercept methods. There were no differences in CO2 measured by OA-ICOS or IRMS compared with IC when the plateau method was used. When the intercept method was used, CO2 using OA-ICOS did not differ from IC, but CO2 measured using IRMS was significantly lower than IC. Accuracy (similar to 1-5%), precision (similar to 8%), intraclass correlation coefficients (R = 0.87-90), and root mean squared error (30-40 liters/day) of CO2 measured by OA-ICOS and IRMS were similar. Both OA-ICOS and IRMS produced measurements of CO2 with comparable accuracy and precision compared with IC.