Although telomere attrition is associated with the process of normal ageing, shorter telomere length (TL) has been associated with acute and chronic stressors. A neurobiological factor hypothesised to be responsible for this accelerated attrition is the dysregulation of the cortisol stress response, which can induce DNA damage affecting DNA telomeric caps. Marked sex differences are reported in both the cortisol stress response and telomere dynamics, yet no explicit investigation of sex specificity on the relationship between cortisol and TL exists. This study used mathematical equation modelling to describe the relationship between diurnal cortisol levels and telomere length within the context of sex, in a healthy population. Cortisol awakening responses (CAR) were measured via ELISA methodology in fifty-one healthy participants (28 males, 23 females). qPCRs determined TL from genomic DNA extracted from saliva. To assess the effect of free cortisol on relative TL ratio, a semi-log regression plot of the two variables trended for sex were fitted using spline curves. Results demonstrated significant differences between males and females in the relationship defining CAR and TL association (p = 0.03). These results suggest the relationship is not linear and can be represented as a complex arcsin function, and that the patterns are opposite in males and females. Males demonstrate a positive correlation, with higher levels of CAR being associated with longer telomere sequences. Females demonstrated a negative correlation. Future studies must carefully take into consideration moderating factors such as sex, and sex hormones across the lifespan when investigating telomere length.

中文翻译：

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皮质醇觉醒反应对端粒长度的影响：男性和女性的趋势

尽管端粒磨损与正常衰老过程有关，但较短的端粒长度 (TL) 与急性和慢性压力源有关。假设造成这种加速损耗的一个神经生物学因素是皮质醇应激反应的失调，它可以诱导影响 DNA 端粒帽的 DNA 损伤。皮质醇应激反应和端粒动力学均报告了显着的性别差异，但尚无关于皮质醇与 TL 之间关系的性别特异性的明确调查。本研究使用数学方程模型来描述健康人群中在性背景下昼夜皮质醇水平与端粒长度之间的关系。通过 ELISA 方法在 51 名健康参与者（28 名男性，23 名女性）。qPCRs 从唾液中提取的基因组 DNA 确定 TL。为了评估游离皮质醇对相对 TL 比率的影响，使用样条曲线拟合了两个趋向于性别的变量的半对数回归图。结果表明，在定义 CAR 和 TL 关联的关系中，男性和女性之间存在显着差异（p  = 0.03)。这些结果表明这种关系不是线性的，可以表示为一个复杂的反正弦函数，并且男性和女性的模式是相反的。男性表现出正相关，较高水平的 CAR 与较长的端粒序列相关。女性表现出负相关。在研究端粒长度时，未来的研究必须仔细考虑调节因素，例如性和性激素。