Department of Developmental Psychology, Behavioural Science Institute, Radboud University Nijmegen, 6500 HE, Nijmegen, The Netherlands.
Early Hum Dev. 2010 Jan;86(1):13-6. doi: 10.1016/j.earlhumdev.2009.12.003. Epub 2010 Jan 6.
Many studies have incorporated cortisol measurements when studying infant development, but descriptions of normal development of basal cortisol levels in large study populations are scarce. The present study aimed to establish norm values for infant basal cortisol levels and to examine the development of intra-individual variability in the first year of life.
More than 2500 cortisol samples were collected in 300 infants at three different ages. At each age four 1100h samples were collected to determine average cortisol levels and intra-individual variability. The development of basal cortisol levels and intra-individual variability was analyzed with multilevel growth curve modeling.
Norm tables with 90 and 95% intervals are presented. Basal cortisol levels decreased gradually over the year. Intra-individual variability was relatively large and stable in the first half year but decreased towards the end of the year.
The results of this study will aid researchers in evaluating cortisol data collected in early infancy. It also underscores the importance of taking intra-individual cortisol variability into account in studies involving infants.
许多研究在研究婴儿发育时都纳入了皮质醇测量，但关于大人群基础皮质醇水平正常发育的描述却很少。本研究旨在建立婴儿基础皮质醇水平的正常数值，并研究个体内变异性在生命第一年的发展。
在 300 名婴儿的三个不同年龄阶段采集了超过 2500 个皮质醇样本。在每个年龄阶段，采集了四个 1100h 的样本，以确定平均皮质醇水平和个体内变异性。采用多层次增长曲线模型分析基础皮质醇水平和个体内变异性的发展。
呈现了 90%和 95%区间的正态表。基础皮质醇水平在一年内逐渐下降。个体内变异性在前半年相对较大且稳定，但在年底有所下降。
本研究的结果将有助于研究人员评估婴儿早期采集的皮质醇数据。它还强调了在涉及婴儿的研究中考虑个体内皮质醇变异性的重要性。
