Stress in healthy young women : psychophysiological stress response and sleep in the context of adverse childhood experiences and daily stress

The aim of the present dissertation is to contribute to the knowledge about different aspects of stress and their impact on healthy young women. The relationship between daily stress, presleep arousal, and sleep was investigated and additionally, the association between adverse childhood experiences (ACEs) and psychophysiological stress response was analysed.
Daily stress and prelseep arousal are well-known factors in the development of sleep disturbances and insomnia. The article daily stress, presleep arousal, and sleep in healthy young women: a daily life computerized sleep diary and actigraphy study aimed to further elucidate the mediating role of presleep arousal in the relationship between daily stress and sleep. Subjective sleep quality and actigraphic sleep efficiency were investigated both within- and between-participants. Multilevel modelling was applied on electronically assessed data comprising 14 consecutive nights in 145 healthy young women. The relationship between daily stress and worsened subjective sleep quality was mediated by somatic arousal on the between-participant level, and by cognitive arousal on the within-participants level. Unexpectedly, healthy young women showed higher actigraphic sleep efficiency following days with above average stress and somatic arousal. It was concluded, that healthy young women might even be able to compensate for days with above average levels of stress and arousal, which suggests further exploration of the mechanism causing this potentially adaptive regulation.
ACEs have been associated with alterations of psychobiological stress systems and various negative health outcomes. Studies on healthy participants are still scarce, however, attenuated endocrine and cardiovascular stress reactivity in relation to childhood adversity has been observed. Therefore, the article blunted endocrine and cardiovascular reactivity in young healthy women reporting a history of childhood adversity aimed to replicate the attenuated endocrine and cardiovascular stress reactivity in association with ACEs in 104 healthy young women. Furthermore, the association between stress reactivity and duration, as well as age of occurrence of ACEs was investigated. Participants underwent psychosocial stress testing and free saliva cortisol and heart rate were assessed. Results confirmed that a higher number of ACEs was associated with a blunted endocrine and cardiovascular stress response to the psychosocial stress task, and that especially longer duration and occurrence before menarche of ACEs were significantly associated with attenuated cortisol response. It was concluded that ACEs, particularly if they occurred repeatedly or chronically, show an association with blunted stress reactivity in healthy young women.
The article adverse childhood experiences are associated with blunted sympathetic stress responsivity in healthy young women aimed at clarifying the role of the sympathetic and parasympathetic branches of the autonomic nervous system in the relationship between ACEs and blunted heart rate response. Systolic blood pressure (SBP) and respiratory sinus arrhythmia (RSA) were assessed during baseline and psychosocial stress testing in 129 healthy young women as measures of sympathetic and parasympathetic cardiovascular activity, respectively. Higher number of ACEs was correlated with blunted SBP stress reactivity but not with RSA reactivity after controlling for respiratory rate. Also, earlier age of occurrence of ACEs was associated with blunted SBP reactivity on a trend level. In conclusion, childhood adversity was associated with down-regulation of sympathetic stress responsivity but no alteration of parasympathetic functioning in adulthood. Future research will need to clarify whether this indicates a risk for negative health outcomes or might even be a sign of adaptive stress resistance.