Ethnicity and Differences in Pain Perception

Article abstract: Although ethnic differences in pain perception are well documented, the underlying mechanism for these outcomes has not been established. µ-opioid receptor (MOR) function might contribute to this disparity, given that MORs play a key role in pain sensitivity and modulation. However, no study has characterized ethnic differences in MOR physiology. The present study sought to address this knowledge gap by examining differences in µ-selective agonist binding potential (BPND; [11C]-Carfentanil) between 27 non-Hispanic Black (NHB) and 27 demographically-similar, non-Hispanic White (NHW) participants. Participants completed questionnaires and two 90-minute high-resolution research tomograph PET imaging sessions. During PET imaging, a capsaicin or control cream was applied to individuals’ arms and pain ratings were collected. Bonferroni-corrected PET volumes of interest analyses revealed significantly greater [11C]-Carfentanil BPND among NHB participants in bilateral ventral striata [(left): F1,52=16.38, p<.001; (right): F1,52=21.76, p<.001], bilateral dorsolateral prefrontal cortices [(left) F1,52=17.3, p<.001; (right): F1,52=14.17, p<.001], bilateral subgenual anterior cingulate cortex [(left): F1,52=10.4, p=.002; (right): F1,52=12.91, p=.001], and right insula (F1,52=11.0, p=.002). However, there were no significant main effects of Condition or Ethnicity x Condition interaction effects across models, likely attributable to individual variability in the direction of change within groups. BPND values were significantly correlated with pain ratings collected during the capsaicin condition (r range = .34-.46, p range =.01-.001). Results suggest that NHB individuals might have generally greater unoccupied MOR density than NHW peers. Findings have implications for physiological differences underlying ethnicity-related pain disparities. If replicated, these results further emphasize the need for tailored treatments in historically underserved populations.

Non-Hispanic black adults exhibit greater μ-selective agonist binding potential (BP_ND; [¹¹C]carfentanil) in several different brain regions compared with non-Hispanic white adults, suggesting μ-opioid receptor (MOR) function may play a role in ethnic differences in pain perception. This is according to a study in PAIN.

Previous studies have established ethnic differences in pain perception; however, the underlying mechanism for these outcomes has not been well established. In this study, investigators used μ-opioid imaging outcomes gathered from high-resolution research tomograph PET scanning to examine differences in BPND; [¹¹C]carfentanil among healthy adults identifying as non-Hispanic black and non-Hispanic white (n=54). Participants were matched for age, sex, education, and income. During a PET imaging session, researchers applied either a capsaicin or control cream to each participant’s arms and measured pain ratings. Perceived racial discrimination and pain sensitivity were assessed and compared between groups.

Compared with non-Hispanic white individuals, people who identified as non-Hispanic black reported a higher rate of perceived racial discrimination (P <.001). The researchers found...

 

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