Salivary α-Amylase Reactivity to Laboratory Social Stress With and Without Acute Sleep Restriction

A growing literature suggests that salivary α-amylase (sAA) may serve as a minimally invasive marker of psychophysiological stress-induced activity of the sympathetic-adrenal-medullary system (SAM). Previous inconsistencies in the experimental literature relating sAA response to short sleep duration may be as a result of poor reliability of self-reported sleep time, suggesting that further examination of sAA response following verified sleep loss is required. With regard to the potential usefulness of sAA as a biomarker of psychosocial stress in the laboratory, previous research has also relied primarily on traditional psychosocial stress protocols, including physically present evaluative observers. The present study aimed to examine sAA response following a period of verified acute sleep restriction compared to a rested condition, in addition to examining the sensitivity of sAA response to a laboratory stress protocol that exposed participants to negative social evaluation presented by video relay. One hundred and eight healthy young adults (age 17-22 years; M = 18.39 years, SD = 0.87) completed a laboratory social stress task and provided saliva samples pre- and post-stressor presentation, after a night of partial sleep restriction or a full night's rest. Marked increases in sAA activity to the video-relayed stressor were observed in both rested and sleep restricted groups. Further, sleep restricted participants exhibited significantly increased basal levels of sAA activity. The data corroborate previous limited data indicating a general upregulation of sAA activity following poor sleep and support previous findings concerning the efficacy of an experimental paradigm that presents laboratory social stress by means of video recording.