Abstract

Stress, via the activation of the stress response system, has been linked to the emergence of cardiovascular precursors. The majority of studies relating the autonomic nervous system and the hypothalamic pituitary adrenal (HPA) axis, the two main branches of the stress response system, to stress and cardiovascular precursors have focused on examining each branch of the stress response system in isolation. However, considering only these singular associations disregards the structural and functional inter-connection between the stress response systems. Examining the inter-relation between the stress systems among children and adolescents is particular opportune given the emergence of cardiovascular precursors early in the life course. The objective of the current research program was to examine the patterning of the cardio-autonomic nervous system and HPA axis, and whether the inter-relation between these stress systems was associated with cardiovascular precursors among children.
Three studies were conducted. Study 1 demonstrated the patterning of the stress response system, and found that the inter-relation between stress systems better accounted for the relation between stress and the stress response system than either system alone. Extending these results, Study 2 demonstrated that the inter-relation between stress systems was associated with cardiovascular precursors in a population-based sample of children. Exposure to stress moderated the association between inter-relation of stress systems and cardiovascular precursors, which was more robust among children with greater stressful life events. Study 3 replicated these results in a sample of children at-risk for obesity, and demonstrated that the inter-relation between stress systems was related to cardiovascular precursors among at-risk children with greater stress exposure.
Overall, this research program found that the inter-relation between the stress systems was related to cardiovascular precursors, and children’s environmental exposure to stressful events influenced these associations. Future studies should consider using an inter-relation approach, which may provide greater insight into the association between stress and cardiovascular health than considering the stress systems independently. The patterning of the stress response system has implications for future studies examining how stress “gets under the skin” to promote the development of disease.