Gustafsson Per A, Gustafsson Per E, Anckarsäter Henrik, Lichtenstein Paul, Ljung Therese, Nelson Nina, Larsson Henrik
Department of Clinical and Experimental Medicine, Child and Adolescent Psychiatry, Linköping University, Sweden.
Twin Res Hum Genet. 2011 Dec;14(6):553-61. doi: 10.1375/twin.14.6.553.
The normal development of cortisol regulation during childhood is thought to be influenced by a complex interplay between environmental and genetic factors.
The aim of this study was to estimate genetic and environmental influences on basal cortisol levels in a sample of 151 twin pairs aged 9-16 years. Salivary cortisol was collected on two consecutive days when the children attended school--immediately after awakening, 30 min post-awakening and at bedtime.
Heritability was highest (60%) for cortisol levels about 30 min after awakening. For samples taken immediately at awakening heritability was less pronounced (28%) and in the evening low (8%).
The limited genetic influence on evening levels, moderate on cortisol at awakening and high on awakening response, might imply two genetic regulation patterns, one specifically for awakening response and one for the circadian rhythm proper. These findings could explain divergent results in previous studies and highlight the importance of taking the circadian rhythm into account in studies of cortisol levels in children.
儿童期皮质醇调节的正常发育被认为受环境和遗传因素之间复杂相互作用的影响。
本研究的目的是评估151对9至16岁双胞胎样本中遗传和环境对基础皮质醇水平的影响。当孩子们上学时，在连续两天收集唾液皮质醇——醒来后立即、醒来后30分钟以及就寝时间。
醒来后约30分钟时皮质醇水平的遗传度最高（60%）。醒来后立即采集的样本遗传度不太明显（28%），而晚上的遗传度较低（8%）。
对晚上水平的遗传影响有限，对醒来时皮质醇的影响中等，对醒来反应的影响较大，这可能意味着两种遗传调节模式，一种专门用于醒来反应，另一种用于正常的昼夜节律。这些发现可以解释先前研究中的不同结果，并突出在儿童皮质醇水平研究中考虑昼夜节律的重要性。
