Background: Stress system consists of the hypothalamicpituitary-adrenal (HPA) axis and the locus caeruleus/norepinephrine-autonomic nervous system (ANS). Traditionally, HPA axis activity is evaluated by measuring its end-product cortisol, while the activity of ANS is assessed using heart rate variability (HRV) indices. Alterations in cortisol levels and HRV measures during laboratory-based stress tasks were extensively studied in previous research. However, scarce data exist on the associations of HRV measures with the levels of other adrenal steroid hormones under baseline conditions. Thus, we aimed to evaluate the activity of the HPA axis by measuring salivary cortisol, cortisone, dehydroepiandrosterone (DHEA) levels, and their ratios and to examine its association with HRV measures in a sample of healthy young and middle-aged adults.
Methods: For each participant (n=40), three data collection sessions taking place at the same time of the day were scheduled within five working days. Participants completed a self-reported questionnaire on sociodemographic and lifestyle characteristics, filled out t h e Perceived Stress Scale and State-Trait Anxiety Inventory. Also, saliva samples were collected, and physiological measures, including resting HR and HRV, were recorded during three data collection sessions.
Results: Statistically significant associations between diminished parasympathetic vagal tone evaluated by time domain HRV measures and higher salivary cortisol, lower DHEA levels, as well as decreased DHEA to cortisol ratio, were found. Also, physiological stress indicators (i.e., HRV) showed greater intraindividual stability compared with biochemical biomarkers (i.e., salivary steroid hormones) within five days.
Conclusions: Our findings suggest that both cortisol and DHEA mediate the link between two stress-sensitive homeostatic systems.
Uvod: Sistem stresa se sastoji od hipotalamusno-hipofiznoadrenalne (HPA) ose i plavog jedra/norepinefrina - autonomnog nervnog sistema (ANS). Tradicionalno, aktivnost HPA ose se procenjuje merenjem kortizola u krajnjem produktu, dok se aktivnost ANS procenjuje pomoću indeksa promenljivosti otkucaja srca (HRV). Promene nivoa kortizola i HRV merene tokom stresnih zadataka u laboratorijskim uslovima su detaljno proučavane u prethodnim istraživanjima. Međutim, postoje nedovoljni podaci o povezanosti merenja HRV-a sa nivoima ostalih nadbubrežnih steroidnih hormona u osnovnom stanju. Stoga smo želeli da procenimo aktivnost HPA ose merenjem nivoa kortizola iz pljuvačke, kortizona i dehidroepiandrosterona (DHEA) i da ispitamo njihovu povezanost sa HRV merenjima na uzorku zdravih mladih ljudi i ljudi srednjih godina.
Metode: Za svakog učesnika (n=40) su zakazane tri sesije prikupljanja podataka u isto doba dana tokom pet dana. Učesnici su samostalno popunili upitnik o sociodemografskim i životnim karakteristikama, ispunili su Percipiranu skalu stresa i Upitnik o anksioznosti kao stanja i osobine ličnosti. Takođe, prikupljeni su uzorci pljuvačke i urađena su fiziološka merenja, uključujući HR i HRV u mirovanju tokom tri sesije prikupljanja podataka.
Rezultati: Otkrivene su statistički značajne veze između smanjenog parasimpatičkog vagalnog tona procenjenog vremenskim domenom HRV i višeg nivoa kortizola u pljuvački, nižeg nivoa DHEA, kao i smanjenog racija DHEA i kortizola. Takođe, pokazatelji fiziološkog stresa (tj. HRV) pokazali su veću intraindividualnu stabilnost u poređenju sa biohemijskim biomarkerima (tj. steroidnim hormonima pljuvačke) u periodu od pet dana.
Zaključak: Naša otkrića sugerišu da kortizol i DHEA posreduju u vezi između dva homeostatska sistema osetljiva na stres.
Keywords: autonomic nervous system; heart rate variability; hypothalamic-pituitary-adrenal axis; steroid hormones; stress biomarkers.
2021 Eglė Mazgelytė, Gintaras Chomentauskas, Edita Dereškevičiūtė, Virginija Rekienė, Audronė Jakaitienė, Tomas Petrėnas, Jurgita Songailienė, Algirdas Utkus, Kučinskienė Zita Aušrelė, Dovilė Karčiauskaitė, published by CEON/CEES.