Ethnic Disparities in Total Joint Arthroplasty: Pain and Stress-Related Media

与膝骨关节炎（OA）相关的疼痛的特征在于（a） 个体;和（B）与组织损伤的放射学测量的适度关联。种族背景是 这是导致疼痛报告和疼痛相关行为变化的一个重要因素。最近的研究 表明与白色人相比，非裔美国人个体表现出较低疼痛耐受水平， 相对受损的疼痛调节机制（例如，血压对压力源的反应）。还存在 证据表明，内源性阿片样物质的释放有助于这些机制的功能。总体目标 因此，这项研究的目的是确定热刺激是否会引起阿片类神经传递的变化。 热刺激部分介导了膝关节OA患者热痛反应的种族差异。 36名膝关节OA男性（18名非洲裔美国人，18名白色）将接受PET贝恩成像， 阿片放射性配体[18F]氟乙基-二丙诺啡在两种条件下：（a）暴露于热 根据个人疼痛阈值量身定制的刺激，将产生类似的、中等程度的热疼痛 患者之间的强度;和（B）暴露于将产生以下感知的热刺激 感觉控制条件（sensory control condition）患者将产生视觉模拟量表（VAS）评分 疼痛强度和刺激后的不愉快。我们预计，与非洲裔美国人相比， 白色患者将（a）产生疼痛不愉快等级的显著更大增加;和（B）表现出 内侧疼痛系统结构中较低的阿片样物质神经传递（例如，杏仁核、前扣带皮层） 从感官控制到疼痛的热刺激，即使在控制了心理社会变量之后， 例如抑郁症状水平。我们还预计，刺激诱发的阿片类药物的变化， 内侧疼痛系统结构中的神经传递将部分介导 疼痛和不愉快评分的变化。我们预计，拟议的研究将产生新的研究。 这将导致（a）更好地理解其他生理或心理社会变量， 疼痛反应和内源性疼痛调节功能的种族差异;（B）新的或 改进当前用于疼痛管理的药理学或行为/心理社会干预;以及（c） 减少患者对这些干预措施的期望和偏好的种族差异。

Pain associated with knee osteoarthritis (OA) is characterized by (a) high levels of variability among individuals; and (b) modest associations with radiographic measures of tissue damage. Ethnic background is one important factor that contributes to variation in pain reports and pain-related behavior. Recent studies indicate that African-American, compared to white, individuals exhibit lower pain tolerance levels and relatively impaired pain regulatory mechanisms (e.g., blood pressure responses to stressors). There also is evidence that endogenous opioid release contributes to the function of these mechanisms. The overall aim of the proposed study, then, is detemine whether changes in opioid neurotransmission evoked by thermal heat stimulation partially mediate ethnic differences in thermal pain responses among patients with knee OA. Thirty-six men (18 African-American, 18 white) with knee OA will undergo PET bain imaging with the opiodergic radioligand [18F] fluoroethyl-diprenorphine under two conditions: (a) exposure to thermal heat stimulation, tailored to individual pain thresholds, that will produce similar, moderate, levels of thermal pain intensity across patients; and (b) exposure to thermal heat stimulation that will produce perceptions of warmth across patients (sensory control condition). Patients will produce visual analogue scale (VAS) ratings of pain intensity and unpleasantness following stimulation. We expect that African-American, compared to white patients, will (a) produce significantly greater increases in pain unpleasantness ratings; and (b) exhibit lower opioid neurotransmission in medial pain system structures (e.g., amygdala, anterior cingulate cortex) from sensory control to painful thermal heat stimulation, even after controlling for psychosocial variables such as depressive symptom levels. We also expect that stimulation-evoked change in opioid neurotransmission in medial pain system structures will partially mediate the ethnic group difference in change in pain unpleasantness ratings. We anticipate that the proposed research will generate new sttudies that will lead to (a) improved understanding of additional physiologic or psychosocial variables that contribute to ethnic differences in pain responses and endogenous pain regulatory function; (b) development of new or refinement of current pharmacologic or behavioral/psychosocial interventions for pain management; and (c) reductions in ethnic disparities in patients' expectations of and preferences for these interventions.