title: An increase in salivary interleukin-6 level following acute psychosocial stress and its biological correlates in healthy young adults.
abstract: Although interleukin-6 (IL-6) has been investigated frequently in stress research, knowledge regarding the biological processes of IL-6 in association with psychosocial stress remains incomplete. This study focused on salivary IL-6 and reports its temporal variation and biological correlates following acute psychosocial stress. Fifty healthy young adults (39 male and 11 female students) were subjected to the psychosocial stress test 'Trier Social Stress Test' (TSST), wherein the participants were asked to deliver a speech and perform a mental arithmetic task in front of 2 audiences. Collection of saliva samples, measurement of heart rate, and assessment of negative moods by visual analogue scales were conducted before, during, and after TSST. Salivary IL-6 levels increased by approximately 50% in response to the TSST and remained elevated for 20 min after the stress tasks were completed. Cluster analyses revealed that individuals with sustained elevation of IL-6 levels following the TSST exhibited a lower cortisol response compared to individuals with lower IL-6 levels. In the correlation analyses, a greater IL-6 response was associated with a higher heart rate during the mental arithmetic task (r=.351, p<.05) and with a lower cortisol response (r=-.302, p<.05). This study demonstrates that salivary IL-6 levels are elevated for a relatively long period following acute psychosocial stress, and suggests that sympathetic activity and cortisol secretion are involved in elevation of salivary IL-6 levels.
authors.affiliation: Health Administration and Psychosocial Factor Research Group, National Institute of Occupational Safety and Health, Japan, Kanagawa, Japan. Electronic address: izawa0810@gmail.com.
authors.forename: Shuhei
authors.initials: S
authors.lastname: Izawa
authors.forename: Nagisa
authors.initials: N
authors.lastname: Sugaya
authors.forename: Kenta
authors.initials: K
authors.lastname: Kimura
authors.forename: Namiko
authors.initials: N
authors.lastname: Ogawa
authors.forename: Kosuke C
authors.initials: KC
authors.lastname: Yamada
authors.forename: Kentaro
authors.initials: K
authors.lastname: Shirotsuki
authors.forename: Ikuyo
authors.initials: I
authors.lastname: Mikami
authors.forename: Kanako
authors.initials: K
authors.lastname: Hirata
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Nagano
authors.forename: Shinobu
authors.initials: S
authors.lastname: Nomura
mesh_terms: D000704:Analysis of Variance; D004562:Electrocardiography; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006339:Heart Rate; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism*; D008297:Male; D012463:Saliva / Q000378:metabolism*; D013223:Statistics as Topic; D013315:Stress, Psychological / Q000378:metabolism*; D013997:Time Factors; D064232:Visual Analog Scale; D055815:Young Adult
chemical_list: D015850:Interleukin-6; D006854:Hydrocortisone
keywords: Cortisol; Heart rate; Interleukin-6; Psychosocial stress; Saliva