Salivary α‐amylase stress reactivity across different age groups

Department of Psychology, Technische Universität Dresden, Dresden, Germany.
Psychophysiology (Impact Factor: 3.18). 05/2010; 47(3):587-95. DOI: 10.1111/j.1469-8986.2009.00957.x
Source: PubMed

ABSTRACT tract Salivary alpha-amylase (sAA) increases rapidly in response to psychosocial stress in young adults, but no direct comparisons between different age groups across the life span have been made. Secretion of sAA and cortisol was assessed in children, young adults, and older adults after exposure to the Trier Social Stress Test. Additionally, cardiovascular activity was measured in both adult groups. Older adults showed attenuated sAA, heart rate (HR), and heart rate variability (HRV) responses. Furthermore, we found higher sAA but lower cortisol at baseline as well as lower sAA and cortisol responses in children. Age x sex interactions were observed only for cortisol with higher responses in older male participants. No associations between the parameters were found. These results implicate sAA as an alternative or additional sympathetic stress marker throughout the life span, with marked and rapid stress responsiveness in three relevant age groups.

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Available from: Clemens Kirschbaum, Aug 30, 2015
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    • "Moreover, we tested whether sAA levels significantly changed over time in each trial by calculating general linear models with repeated salivary measures in each trial separately to obtain information regarding significance of main effects of time. As we decided against weight adjustment of infusion concentrations and in light of previously reported associations of cardiovascular risk factors and indicators for SNS activity (Strahler et al., 2010) we controlled for the cardiovascular risk factors BMI, age, and MAP in all repeated sAA analyses as an a-priori defined set of covariates. "
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    ABSTRACT: BACKGROUND: Mental stress reliably induces increases in salivary alpha amylase (sAA), a suggested surrogate marker for sympathetic nervous system (SNS) reactivity. While stress-induced sAA increases correlate with norepinephrine (NE) secretion, a potential mediating role of noradrenergic mechanisms remains unclear. In this study, we investigated for the first time in humans whether a NE-stress-reactivity mimicking NE-infusion with and without alpha-adrenergic blockade by phentolamine would induce changes in sAA. METHODS: In a single-blind placebo-controlled within-subjects design, 21 healthy men (29-66 years) took part in three different experimental trials varying in terms of substance infusion with a 1-min first infusion followed by a 15-min second infusion: saline-infusion (trial-1), NE-infusion (5 μg/min) without alpha-adrenergic blockade (trial-2), and with phentolamine-induced non-selective blockade of alpha1- and alpha2-adrenergic receptors (trial-3). Saliva samples were collected immediately before, during, and several times after substance infusion in addition to blood pressure and heart rate readings. RESULTS: Experimental trials significantly differed in sAA reactivity to substance-infusion (p=.001) with higher sAA reactivity following NE-infusion with (trial-3; p=.001) and without alpha-adrenergic-blockade (trial-2; p=.004) as compared to placebo-infusion (trial-1); sAA infusion reactivity did not differ between trial-2 and trial-3 (p=.29). Effective phentolamine application was verified by blood pressure and heart rate infusion reactivity. Salivary cortisol was not affected by NE, either with or without alpha-adrenergic-blockade. CONCLUSIONS: We found that NE-infusion stimulates sAA secretion, regardless of co-administered non-selective alpha-adrenergic blockade by phentolamine, suggesting that the mechanism underlying stress-induced sAA increases may involve NE.
    Psychoneuroendocrinology 08/2014; 49C(1):290-298. DOI:10.1016/j.psyneuen.2014.07.023 · 5.59 Impact Factor
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    • "In our study we did not find sex differences in the cortisol response to the stress induction. This finding is not in agreement with previous research that showed that men reacted to the TSST with a larger cortisol increase than women (Kudielka et al., 2004; Strahler et al., 2010; Almela et al., 2011b). Additionally, we consider that the overall cortisol response to the TSST was moderate because the mean peak of cortisol was 6.5 nmol/l, whereas in the later studies cortisol concentrations have reached 10 nmol/l or more. "
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    • "Salivary α-amylase After thawing, saliva samples were centrifuged at 3000 rpm for 3 min. Salivary α-amylase was measured by a quantitative enzyme kinetic method as described elsewhere (Strahler et al., 2010). Intraand inter-assay precisions expressed as percent coefficient of variation were below 10%. "
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    ABSTRACT: Identification of genetic factors that influence stress reactivity is important in order to link environmental demands, particularly adversity to disease outcome. There is ample literature on genetic contribution to the endocrine stress response, while evidence for genetic contribution to individual differences in autonomic nervous system function is sparse and produced conflicting results. Here, we investigated the influence of two polymorphisms in the Catechol-o-methyltransferase (COMT) and serotonin transporter (5-HTT; SCL6A4) gene. We examined the autonomic stress response to the Trier Social Stress Test for Children in 115 children. Salivary α-amylase (sAA) was obtained prior to the stressor and repeatedly during recovery as a marker of autonomic reactivity. Furthermore, heart rate (HR) and heart rate variability (HRV) were monitored continuously. We found differences in ANS stress response associated with each polymorphism (all p<.05). Children with the L variant of 5-HTTLPR showed a higher increase and sharper recovery of sAA in response to stress than those with S variants. For HR, we found differences associated with COMT, i.e. children carrying at least one met allele showed lower mean HR increase and slower HR recovery in response to the stressor compared to those with two val alleles (p<.001) as well as a significant decrease in heart rate variability (p<.05). Our findings indicate that these two polymorphisms do indeed influence the ANS response to stress. This study provides further evidence for the crucial role of genetic factors in the modulation of differences in the acute stress response during childhood.
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