Department of Anthropology, Case Western Reserve University, Cleveland, Ohio, USA.
Department of Anthropology, Washington University, St. Louis, Missouri, USA.
Am J Hum Biol. 2022 Apr;34(4):e23670. doi: 10.1002/ajhb.23670. Epub 2021 Aug 23.
Connecting traits to biological pathways and genes relies on stable observations. Researchers typically determine traits once, expecting careful study protocols to yield measurements free of noise. This report examines that expectation with test-retest repeatability analyses for traits used regularly in research on adaptation to high-altitude hypoxia, often in settings without climate control.
Two hundred ninety-one ethnic Tibetan women residing from 3500 to 4200 m in Upper Mustang District, Nepal, provided three observations of hemoglobin concentration, percent of oxygen saturation of hemoglobin, and pulse by noninvasive pulse oximetry under conditions designed to minimize environmental noise.
High-intraclass correlation coefficients and low within-subject coefficients of variation reflected consistent measurements. Percent of oxygen saturation had the highest intraclass correlation coefficient and the smallest within-subject coefficient of variability; measurement noise occurred mainly in the lower values. Hemoglobin concentration and pulse presented slightly higher within-subject coefficients of variation; measurement noise occurred across the range of values. The women had performed the same measurements 7 years earlier using the same devices and protocol. The sample means and SD observed across 7 years differed little. Hemoglobin concentration increased substantially after menopause.
Analyzing repeatability features of traits may improve our interpretation of statistical analyses and detection of variation from measurement or biology. The high levels of measurement repeatability and biological stability support the continued use of these robust traits for investigating human adaptation in this altitude range.
将特征与生物途径和基因联系起来依赖于稳定的观察。研究人员通常会进行一次特征测定，期望仔细的研究方案能产生无噪声的测量结果。本报告通过对高海拔低氧适应研究中常用特征的重测重复性分析来检验这一期望，这些特征通常在没有气候控制的环境中进行研究。
291 名居住在尼泊尔上木斯塘地区（海拔 3500 至 4200 米）的藏族女性，在旨在最大限度减少环境噪声的条件下，通过非侵入性脉搏血氧仪进行了 3 次血红蛋白浓度、血红蛋白血氧饱和度百分比和脉搏的测量。
高组内相关系数和低个体内变异系数反映了一致的测量结果。血氧饱和度百分比的组内相关系数最高，个体内变异系数最小；测量噪声主要发生在较低值。血红蛋白浓度和脉搏的个体内变异系数略高；测量噪声发生在整个值范围内。这些女性在 7 年前使用相同的设备和方案进行了相同的测量。7 年来观察到的样本平均值和标准差差异不大。绝经后血红蛋白浓度显著增加。
分析特征的可重复性特征可以提高我们对统计分析的解释能力，并有助于检测测量或生物学方面的变异。这些可靠特征具有较高的测量重复性和生物学稳定性，支持继续用于研究该海拔范围内人类的适应能力。
