Modality and sex differences in pain sensitivity during human endotoxemia

摘要: Systemic inflammation can induce pain hypersensitivity in animal and human experimental models, has been proposed to be central clinical conditions. Women are overrepresented many chronic conditions, but studies on sex differences regulation during systemic still scarce. In two randomized double blind placebo controlled experiments, we used low doses of lipopolysaccharide (LPS) as an model inflammation. The first study employed 0.8ng/kg LPS a within-subject design 8 individuals (1 woman), the second 0.6ng/kg between-subject 52 participants (29 women). We investigated effect (a) pressure, heat, cold thresholds, (b) suprathreshold noxious heat sensitivity, (c) conditioned modulation (CPM), between men women. induced significantly lower pressure thresholds compared (mean change with dose being -64±30kPa P=.04; -58±55kPa, P .70). Suprathreshold was not affected by (P's⩾.15). However, made women rated stimuli more painful (P=.01), showed tendency rate (P=.06) placebo. Furthermore, impaired modulation, measure endogenous inhibition, this also restricted (P<.01, for P=.27). Pain sensitivity correlated positively plasma IL-6 IL-8 levels. results show that strongly affects deep pain, rather than cutaneous suggest women's perception is sensitive immune activation men's.