Vagal effects of endocrine HPA axis challenges on resting autonomic activity assessed by heart rate variability measures in healthy humans

Agorastos Agorastos*, Alexandra Heinig, Oliver Stiedl, Torben Hager, Anne Sommer, Jana C. Mueller, Koen R. Schruers, Klaus Wiedemann, Cueneyt Demiralay

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Background: The hypothalamic-pituitary-adrenal axis (I-IPA axis) and the autonomic nervous system (ANS) are considered to play the most crucial role in the pathophysiology of stress responsiveness and are increasingly studied together. However, only few studies have simultaneously assessed HPA axis and ANS activity to investigate their direct interaction in pathophysiology, while no study so far has assessed the dynamic interplay between the two systems in healthy subjects through endocrine challenges.

Methods: The present study assessed the direct effects of overnight pharmacoendocrine HPA axis challenges with dexamethasone (suppression) and metyrapone (stimulation) on ANS activity at rest as determined by linear and nonlinear measures of heart rate variability (HRV) in 39 young healthy individuals.

Results: Findings indicated significant effects of metyrapone, but not dexamethasone on autonomic activity at rest based on HRV measures. HRV after metyrapone was overall significantly reduced in comparison to baseline or post-dexamethasone conditions, while the combined metyrapone-related reduction of HRV measures RMSSD, NN50(%) and HF(%) with concomitant increase of the unifractal scaling coefficient alpha(fast), value jointly indicated a specifically diminished vagal activity.

Conclusions: We provide first data that HPA axis stimulation (metyrapone) is associated with reduced vagal tone, while HPA axis suppression (dexamethasone) has no effect on autonomic modulation of heart function. Our results support a vital role of the parasympathetic nervous system in the interplay between ANS and HPA axis and, thus, in the modulation of stress-related cardiovascular responsiveness and the susceptibility to stress related disorders.

Original languageEnglish
Pages (from-to)196-203
Number of pages8
JournalPsychoneuroendocrinology
Volume102
DOIs
Publication statusPublished - Apr 2019

Keywords

  • Hypothalamus-pituitary-adrenal axis (HPA axis)
  • Autonomic nervous system
  • Heart rate variability
  • Stress
  • Metyrapone
  • Dexamethasone
  • Cortisol
  • Endocrine challenge
  • Vagus
  • CORTICOTROPIN-RELEASING-FACTOR
  • PHARMACOLOGICAL PANIC CHALLENGE
  • FALSE DISCOVERY RATE
  • STRIA TERMINALIS
  • BED NUCLEUS
  • DEXAMETHASONE-SUPPRESSION
  • FUNCTIONAL CONNECTIVITY
  • INHIBITORY CONTROL
  • INTERVAL DYNAMICS
  • FACTOR RECEPTOR-1

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