To analyze in a randomized controlled study whether acute psychological stress
alters local proinflammatory signals in a human model of chronic inflammation
, i.e., gingivitis. Chronic inflammation
represents a crucial factor in a variety of diseases and factors that contribute to the onset and progression of disease. Psychological stress
is assumed to represent such a factor. However, experimental human research in this area is rare.
A total of 25 students (n
= 11 females, 14 males) suffering from gingivitis were subjected to a stress
(public-speaking task) and to a control condition in randomized order. Local concentrations of interleukin (IL)-8 were quantified as an indicator of proinflammatory activity at sites of inflammation
. IL-8 is a strong proinflammatory mediator and involved in a variety of disease processes. Samples were taken at sites of inflammation
versus control condition and 0, 45, and 90 minutes afterward.
A significant main effect (p = .03) of acute stress
on local IL-8 was found. Stress
induced an increase of IL-8-concentrations; univariate effect sizes varied between d
= 0.23 and d
This is the first human experimental in vivo study demonstrating that psychological stress
alters the local concentrations of IL-8 under conditions of chronic inflammation
. It provides direct evidence acute stress
is involved in the regulation of local proinflammatory responses in chronic inflammation
. Future studies should now explore the effects of more enduring stress
conditions and the factors mediating stress
effects on inflammatory signals.
IL = interleukin; GCF = gingival crevicular fluid; CRH = corticotrophin-releasing hormone; SP = substance P.