Race and sex differences in cutaneous pain perception

Objective: The purpose of this study was to determine race and sex differences in cutaneous pain perception. Methods: Pain perception was measured using a suprathreshold evaluation of pain intensity and pain unpleasantness to a series of thermal stimuli in 27 whites (14 men and 13 women) and 24 African Americans (12 men and 12 women). Blood pressure, depressive symptoms, anxiety state levels, and negative mood were assessed before pain testing to examine whether they might account for any sex or race differences in pain perception that emerged. Results: African Americans rated the stimuli as more unpleasant and showed a tendency to rate it as more intense than whites. Women showed a tendency to rate the stimuli as more unpleasant and more intense than men. In addition, systolic blood pressure was inversely related to pain intensity. After statistically adjusting for systolic blood pressure, sex differences in pain unpleasantness were reduced and sex differences in pain intensity were abolished; race differences were unaltered. Conclusions: These differences in pain perception may be associated with different pain mechanisms: in the case of sex, differences in opioid activity and baroreceptor-regulated pain systems; in the case of race, unmeasured psychological characteristics are suggested by the larger differences in ratings of pain unpleasantness than pain intensity.