Goodin Burel R, McGuire Lynanne, Allshouse Mark, Stapleton Laura, Haythornthwaite Jennifer A, Burns Noel, Mayes Lacy A, Edwards Robert R
Department of Psychology, University of Maryland, Baltimore County, Baltimore, Maryland 21250, USA.
J Pain. 2009 Feb;10(2):180-90. doi: 10.1016/j.jpain.2008.08.012. Epub 2008 Nov 17.
Pain catastrophizing is among the most robust predictors of pain outcomes, and a disruption in endogenous pain-inhibitory systems is 1 potential mechanism that may account for increased pain among individuals who report higher pain catastrophizing. Pain catastrophizing may negatively influence diffuse noxious inhibitory controls (DNIC), a measure of endogenous pain inhibition, through complex anatomical circuitry linking cortical responses to pain with processes that modulate pain. The current study examined whether DNIC mediated the relationship between catastrophizing and pain among 35 healthy young adults and examined the moderating effects of sex to determine whether the magnitude or direction of associations differed among men and women. DNIC was assessed using pressure pain thresholds on the forearm before and during a cold pressor task. Using bias-corrected bootstrapped confidence intervals, results showed that diminished DNIC was a significant partial mediator of the relation between greater pain-related catastrophizing and more severe pain ratings. Participant sex moderated these associations; higher catastrophizing predicted lower DNIC for men and women, however, the effect of catastrophizing on pain ratings was partially mediated by DNIC for women only. These findings further support the primary role of pain catastrophizing in modulation of pain outcomes.
These findings support the hypothesis that the heightened pain reported by individuals higher in pain catastrophizing may be related to a disruption in the endogenous modulation of pain, operationalized by assessing DNIC. Whether interventions that reduce pain catastrophizing affect pain outcomes via effects on DNIC is in need of investigation.
疼痛灾难化是疼痛结果最有力的预测因素之一,内源性疼痛抑制系统的紊乱是一种潜在机制,可能解释了在报告更高疼痛灾难化水平的个体中疼痛加剧的现象。疼痛灾难化可能通过将皮质对疼痛的反应与调节疼痛的过程联系起来的复杂解剖回路,对弥漫性伤害性抑制控制(DNIC)产生负面影响,DNIC是一种内源性疼痛抑制的指标。本研究调查了DNIC是否介导了35名健康年轻成年人中灾难化与疼痛之间的关系,并研究了性别的调节作用,以确定男性和女性之间关联的大小或方向是否不同。在冷加压任务之前和期间,通过测量前臂的压力疼痛阈值来评估DNIC。使用偏差校正的自助置信区间,结果表明,DNIC降低是与疼痛相关的更大灾难化和更严重疼痛评分之间关系的显著部分中介因素。参与者的性别调节了这些关联;更高的灾难化水平预测男性和女性的DNIC较低,然而,灾难化对疼痛评分的影响仅在女性中部分由DNIC介导。这些发现进一步支持了疼痛灾难化在疼痛结果调节中的主要作用。
这些发现支持了这样一种假设,即疼痛灾难化程度较高的个体报告的疼痛加剧可能与通过评估DNIC所体现的内源性疼痛调节紊乱有关。减少疼痛灾难化的干预措施是否通过对DNIC的影响来影响疼痛结果,这需要进行研究。