Breit Matthew J, Duncan Nassia M, Dahle Jared H, Catenacci Victoria A, Creasy Seth A, Berman Elena S, Speakman John R, Melanson Edward L
Department of Medicine, Division of Endocrinology, Metabolism, and Diabetes, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.
Department of Biology, United States Air Force Academy, Colorado Springs, Colorado, USA.
Rapid Commun Mass Spectrom. 2024 Oct 15;38(19):e9886. doi: 10.1002/rcm.9886.
The precision of the doubly labeled water (DLW) method is determined by the precision and accuracy of the isotopic measurements. Quality control (QC) procedures to mitigate sample variability require additional measurements if sample duplicates differ more than a factor of instrument precision. We explored the effect of widening QC ranges on total daily energy expenditure (TDEE) determined using the two-point sampling method.
We screened DLW data from 121 individuals for instances where samples were analyzed more than twice using our existing QC criteria (±2.0 per mil [δ] for H and ±0.5 δ for O). We then applied wider QC ranges for accepting duplicate measures and recalculated TDEE.
Widening the H QC range to ±10.0 δ in samples collected on the first day (most enriched) and to ±5.0 δ in samples collected on the final day (less enriched) produced almost identical mean TDEE compared to the originally calculated TDEE (2684 ± 508 vs. 2687 ± 512 kcal/day, p = 0.40). There was a strong correlation with the originally calculated TDEE (r = 0.97, p < 0.001).
Expanding the H QC range to ±10.0 δ for samples collected on the first day and ±5.0 δ for samples collected on the final day provides similar mean TDEE results. These findings may help DLW labs optimize QC criteria and reduce analytical costs.
双标水（DLW）法的精密度取决于同位素测量的精密度和准确性。如果样本复制品之间的差异超过仪器精密度的一个因子，用于减轻样本变异性的质量控制（QC）程序需要额外的测量。我们探讨了扩大QC范围对使用两点采样法测定的每日总能量消耗（TDEE）的影响。
我们根据现有的QC标准（氢为±2.0‰[δ]，氧为±0.5δ）筛选了121名个体的DLW数据，以查找样本被分析两次以上的情况。然后，我们应用更宽的QC范围来接受重复测量，并重新计算TDEE。
将第一天采集的样本（最富集）的氢QC范围扩大到±10.0δ，将最后一天采集的样本（富集程度较低）的氢QC范围扩大到±5.0δ，与最初计算的TDEE相比，产生的平均TDEE几乎相同（2684±508 vs. 2687±512千卡/天，p = 0.40）。与最初计算的TDEE有很强的相关性（r = 0.97，p < 0.001）。
将第一天采集的样本的氢QC范围扩大到±10.0δ，将最后一天采集的样本的氢QC范围扩大到±5.0δ，可提供相似的平均TDEE结果。这些发现可能有助于DLW实验室优化QC标准并降低分析成本。
