Figure 5.

Associations between plasma tumor necrosis factor (TNF)-α and pressure pain thresholds in men and women: In men (left panel), pressure pain thresholds of the low back (A, erector spinae muscle), leg (C, gastrocnemius muscle), and shoulder region (E, deltoid muscle; G, trapezius muscle) showed significant negative associations with plasma levels of TNF-α (assessed 2 hours after injection of 0.4 ng/kg body weight lipopolysaccharide, LPS). In women (right panel), no significant correlations were observed for any muscle group (B, erector spinae muscle; D, gastrocnemius muscle; F, deltoid muscle; H, trapezius muscle). Only women using hormonal contraceptives were included in this study.