PROFITH "PROmoting FITness and Health Through Physical Activity" Research Group, Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Ctra de Alfacar s/n, C.P. 18071, Spain.
PROFITH "PROmoting FITness and Health Through Physical Activity" Research Group, Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Ctra de Alfacar s/n, C.P. 18071, Spain.
Clin Nutr. 2018 Oct;37(5):1618-1624. doi: 10.1016/j.clnu.2017.07.026. Epub 2017 Aug 5.
BACKGROUND & AIMS: A high inter-day reliability is a key factor to analyze the magnitude of change in resting metabolic rate (RMR) after an intervention, and the impact of using different methods for data analysis is not known. The aims of this study were: i) to analyze the impact of methods for data analysis on RMR and respiratory exchange ratio (RER) estimation; ii) to analyze the impact of methods for data analysis on inter-day RMR and RER reliability; iii) to compare inter-day RMR and RER reliability across methods for data analysis in participants who achieved steady state (SS) vs. participants who did not achieve SS.
Seventeen young healthy adults completed two 30-min indirect calorimetry (IC) measures on two consecutive mornings, using two metabolic carts each day. Two methods for data analysis were used: i) Selection of a predefined time interval (TI) every 5 min (1-5 min, 6-10 min, 11-15 min, 16-20 min, 21-25 min, 26-30 min); and TI representing the whole measurement period (0-30 min, 5-30 min, 5-25 min); and ii) Methods based on the selection of the most stable period (SSt methods) (3 min SSt, 4 min SSt, 5 min SSt, 10 min SSt). Additionally, participants were classified as those achieving SS (CV < 10% for VO, VCO and VE, and CV < 5% for RER) and those who did not.
RMR and RER measurements were lower when following SSt methods than when following TI methods (all P < 0.01). Although no significant differences were found between different lengths of SSt, 5 min SSt presented the lowest RMR. There were no differences on the inter-day reliability across methods for data analysis (TI and SSt) (all P > 0.2), and there was no systematic bias when comparing RMR and RER day 1 and day 2 measurements (all P > 0.1). Inter-day reliability was similar in individuals who achieved the SS and individuals who did not achieve it. The results were consistent independently of the metabolic cart used.
The 5 min SSt approach should be the method of choice for analyzing IC measures with metabolic carts. However, achieving SS should not be an inclusion criterion in an IC study with young healthy adults.
日间高度可靠性是分析干预后静息代谢率（RMR）变化幅度的关键因素，目前尚不清楚数据分析方法的影响。本研究的目的是：i）分析数据分析方法对 RMR 和呼吸交换率（RER）估计的影响；ii）分析数据分析方法对日间 RMR 和 RER 可靠性的影响；iii）比较在达到稳定状态（SS）的参与者和未达到 SS 的参与者中，不同数据分析方法的日间 RMR 和 RER 可靠性。
17 名年轻健康成年人在连续两天的早上，分别使用两种代谢车，各进行两次 30 分钟的间接测热法（IC）测量。采用两种数据分析方法：i）每隔 5 分钟选择一个预设时间间隔（TI）（1-5 分钟、6-10 分钟、11-15 分钟、16-20 分钟、21-25 分钟、26-30 分钟）；以及代表整个测量期的 TI（0-30 分钟、5-30 分钟、5-25 分钟）；ii）基于选择最稳定期的方法（SSt 方法）（3 分钟 SSt、4 分钟 SSt、5 分钟 SSt、10 分钟 SSt）。此外，根据 VO、VCO 和 VE 的 CV<10%和 RER 的 CV<5%，将参与者分为达到 SS 的组和未达到 SS 的组。
与 TI 方法相比，采用 SSt 方法时 RMR 和 RER 的测量值较低（均 P<0.01）。尽管不同长度的 SSt 之间没有显著差异，但 5 分钟 SSt 的 RMR 最低。不同数据分析方法（TI 和 SSt）之间的日间可靠性没有差异（均 P>0.2），比较第 1 天和第 2 天的 RMR 和 RER 测量值时没有系统偏差（均 P>0.1）。在达到 SS 的个体和未达到 SS 的个体中，日间可靠性相似。结果独立于使用的代谢车保持一致。
对于使用代谢车分析 IC 测量，5 分钟 SSt 方法应该是首选方法。然而，在年轻健康成年人的 IC 研究中，达到 SS 不应作为纳入标准。
