Individuals with chronic pain due to knee osteoarthritis (OA) are insufficiently physically active, and alterations of facilitatory and inhibitory nociceptive signaling are common in this population. Our objective was to examine the association of these alterations in nociceptive signaling with objective accelerometer-based measures of physical activity in a large observational cohort. We used data from the Multicenter Osteoarthritis Study. Measures of peripheral and central pain sensitivity included pressure pain threshold at the knee and mechanical temporal summation at the wrist, respectively. The presence of descending pain inhibition was assessed by conditioned pain modulation (CPM). Physical activity was quantitatively assessed over 7 days using a lower back-worn activity monitor. Summary metrics included steps/day, activity intensity, and sedentary time. Linear regression analyses were used to evaluate the association of pain sensitivity and the presence of descending pain inhibition with physical activity measures. Data from 1873 participants was analyzed (55.9% female, age = 62.8 ± 10.0 years). People having greater peripheral and central sensitivity showed lower step counts. CPM was not significantly related to any of the physical activity measures, and none of the exposures were significantly related to sedentary time. In this cohort, greater peripheral and central sensitivity were associated with reduced levels of objectively-assessed daily step counts. Further research may investigate ways to modify or treat heightened pain sensitivity as a means to increase physical activity in older adults with knee OA.

中文翻译：

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疼痛敏感性和条件性疼痛调节与体力活动的关联：多中心骨关节炎研究 (MOST) 的发现


因膝骨关节炎 (OA) 导致慢性疼痛的个体体力活动不足，并且促进性和抑制性伤害感受信号的改变在该人群中很常见。我们的目标是在大型观察队列中检查伤害性信号传导的这些变化与基于加速度计的客观身体活动测量之间的关联。我们使用多中心骨关节炎研究的数据。外周和中枢疼痛敏感性的测量分别包括膝部的压痛阈值和腕部的机械时间总和。通过条件性疼痛调节（CPM）评估下行疼痛抑制的存在。使用腰部佩戴的活动监测器对 7 天内的身体活动进行定量评估。摘要指标包括每天的步数、活动强度和久坐时间。线性回归分析用于评估疼痛敏感性和下降性疼痛抑制与体力活动测量之间的关联。对 1873 名参与者的数据进行了分析（55.9% 为女性，年龄 = 62.8 ± 10.0 岁）。外周和中枢敏感性较高的人步数较少。 CPM 与任何体力活动指标均不显着相关，并且所有暴露均与久坐时间不显着相关。在该队列中，较高的外周和中枢敏感性与客观评估的每日步数水平降低相关。进一步的研究可能会探讨改变或治疗疼痛敏感性升高的方法，以此作为增加患有膝骨关节炎的老年人的身体活动的一种手段。