Article

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
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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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    • "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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    • "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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