Salivary Alpha-Amylase as a Biomarker of Stress in Behavioral Medicine

Abstract

In recent years, research in behavioral medicine has become increasingly focused on understanding how chronic and acute exposure to stress impacts health outcomes. During stress, the body's physiological stress systems are activated. These systems closely interact with the immune system and are, thus, importantly implicated in the onset and maintenance of disease states. While much of the research in behavioral medicine that has investigated the effects of stress on disease has focused on the role of the hypothalamic-pituitary-adrenal axis and its downstream biomarker, cortisol, it is evident that the autonomic nervous system (ANS) also plays a crucial role in both the biological stress process and the manifestation and maintenance of stress-related symptoms. In recent years salivary alpha-amylase (sAA) has emerged as a valid and reliable marker of ANS activity in stress research and is therefore an important biomarker to consider in behavioral medicine. In this commentary, we will highlight research relevant for behavioral medicine that has utilized sAA measurements, both basally, and in response to stress, to examine ANS function in clinical populations. We will additionally summarize findings from studies that have examined the effects of various targeted interventions on changes in sAA levels. Through this, our aim is to present evidence that sAA can serve as a feasible biomarker of ANS (dys)function in health and disease. To this end, we will also highlight important methodological considerations for readers to keep in mind when including sAA assessments in their own studies. The overarching goal of this brief commentary is to highlight how a multidimensional approach toward physiological stress measurement can allow researchers to develop a better understanding of physical health and disease states.

Stress Monitoring and Recent Advancements in Wearable Biosensors

“…Alpha-amylase is an enzyme that cleaves large alpha-linked polysaccharides into glucose and maltose to be used as immediate energy sources. While alpha-amylase is not technically a biomarker, literature in recent years has shown that high levels of salivary alpha-amylase may indicate chronic stress ( Nater and Rohleder, 2009 ; Vineetha et al, 2014 ; Steckl and Ray, 2018 ; Ali and Nater, 2020 ). The confirmation of salivary alpha-amylase as a reliable biomarker for stress will allow for greater variability in stress quantification approaches through saliva samples.…”

“…Cortisol is a glucocorticoid hormone, whose release is controlled by the central nervous system, more specifically the HPA axis. Cortisol is currently considered the gold standard for evaluating the activity of the HPA axis ( Ali and Nater, 2020 ). Glucocorticoids are responsible for reallocation of energy to overcome real or anticipated stressors perceived during stress response ( Herman et al, 2016 ).…”

Goal-Focused Emotion-Regulation Therapy (GET) for young adult survivors of testicular cancer: a pilot randomized controlled trial of a biobehavioral intervention protocol

“…Diurnal salivary stress biomarkers We will focus on two salivary stress biomarkers. These include salivary cortisol, as a downstream marker of HPA activity, and salivary α-amylase (sAA), as a proxy measure of SAM activation; they can be measured concomitantly [57] and together offer a comprehensive view of physiological stress, as differing diagnostic and treatment effects have been observed between these markers [58]. Both salivary cortisol and sAA follow a distinct diurnal rhythm: cortisol levels peak approximately 30 min after awakening and decrease throughout the day, whereas sAA has a pronounced decline after awakening followed by an increase across the day [57].…”

Music performance anxiety from the challenge and threat perspective: psychophysiological and performance outcomes

“…Lower anabolic balance is associated with more unfavorable psychological well-being and health outcomes [14,15]. SAA is an enzyme secreted from the salivary glands that has been increasingly used as a marker of the activity of the sympathoadrenal-medullary (SAM) axis, another important regulatory system involved in the response to psychosocial stressors [16][17][18]. Researchers have not investigated cardiovascular differences as a function of general MPA level other than for HR and HR variability (HRV) [8].…”