Biomarkers in stress measurement: A systematic review

Introduction and objectives: There is a broad consensus in the scientific community regarding the possibility of evaluating stress through biological markers associated with the main regulatory systems of this process - the Sympathetic Medullary Adreno (SAM), the Hypothalamic Hypophysial Adrenal (HHA) and the immune systems. However, questions remain regarding the use of biomarkers: a) Which are the most commonly used stress biomarkers? b) Which techniques are recommended for their determination? c) From which biological samples is it advisable to quantify them? The aim of this article is to carry out a systematic review of the specialised literature in order to analyse these questions. Materials and methods: a systematic review was carried out in different databases (Pubmed, PMC and MEDLINE), considering articles from the last ten years. We identified 710 studies that underwent the selection process, 33 of which were finally included in the review. Results and conclusions: To date, numerous reviews have been published with the aim of establishing a link between biomarkers and different problems associated with stress. Although the results are promising, the field faces important challenges such as, for example, finding consensus on the definition of best practices for the use of biomarkers. From the present review we can conclude that the biomarkers predominantly used to determine the activation of the SAM axis are heart rate and blood pressure; as for the HHA axis, cortisol has been the biological marker most commonly measured in blood, saliva or hair. Finally, regarding representative markers of immune system activation due to stress, IL-6 and PCR were the most frequently analysed. (C) 2019 Sociedad Espanola para el Estudio de la Ansiedad y el Estres - SEAS. Published by Elsevier Espana, S.L.U. All rights reserved.