(442) Racial/ethnic differences in experimental pain sensitivity and associated factors – cardiovascular responsiveness and psychological status

Abstract

This study aimed to evaluate the contributions of psychological status and cardiovascular responsiveness to racial/ethnic differences in experimental pain sensitivity. Data collected from 3,159 TMD-free individuals - non-Hispanic white (NHW): 1,637, African-American (AA): 1,012, Asian: 299, and Hispanic: 211 - from the OPPERA prospective cohort study were used. Variables analyzed included: quantitative sensory testing measures for pressure, mechanical cutaneous, and heat pain, cardiovascular responsiveness measures (BP, HR, HR/MAP ratio, and heart rate variability), and psychological status (depression, anxiety, stress, coping, and catastrophizing). Structural equation modeling was used for mediation analyses. Putative mediators that showed significant racial/ethnic differences were entered into the final models simultaneously with age, gender, BMI, geographic study site, and education and income level as covariates. Pain catastrophizing was a significant mediator for the associations between race and heat pain tolerance, heat pain ratings (HPR), heat pain aftersensations (HPA), mechanical cutaneous pain ratings and aftersensations (MCPRAS), and mechanical cutaneous pain temporal summation (MCPTS) for both Asians and AAs compared to NHWs. HR/MAP index showed a significant negative mediating effect on the association between race (AAs vs. NHWs) and heat pain tolerance. Coping negatively mediated the association between race and heat pain tolerance, HPR, and MCPTS in both AAs and Asians, compared to NHWs. Negative emotion was a significant mediator for the associations between race (Asians vs. NHWs) and mechanical cutaneous pain thresholds, HPR, HPA, and MCPRAS. Underlying factors responsible for racial differences in pain sensitivity are complex, but both psychological and cardiovascular factors appear to be relevant mediators. Further clinical and experimental research is required to increase our understanding of the suggested mechanisms explaining racial/ethnic differences in pain sensitivity found in the current study and to extend our findings to clinical pain populations.