Pain, the primary complaint in rheumatoid arthritis (RA), is multifaceted, and may be driven by inflammatory disease activity and central sensitisation. We aimed to ascertain what proportion of RA pain severity is explained by markers of inflammation and quantitative sensory testing (QST) indices of central sensitisation. This was a cross-sectional analysis of data from individuals with clinically active RA. Pain severity was assessed using numerical rating scales and inflammation via 28-joint Disease Activity Score (DAS28) and Ultrasound (Greyscale, Power Doppler). Pain sensitivity was assessed by ‘static’ (tibialis anterior or brachioradialis pressure pain detection threshold-PPT-TA/PPT-BR) and ‘dynamic’ (temporal summation-TS, conditioned pain modulation-CPM) QST. Bivariate associations used Spearman’s correlation coefficients, and multivariable linear regression models determined relative contributions to pain severity. In bivariate analyses of N = 96 (age 65 ± 10y, 77% females) people with RA, pain severity was significantly associated with inflammation indices (r = 0.20 to 0.55), and CPM (r=-0.26). In multivariable models that included TS, CPM, age, sex, and body mass index, inflammation indices remained significantly associated with pain severity. Multivariable models explained 22 to 27% of pain variance. Heterogeneity was apparent for associations with pain between subscores for pain now, strongest or average over the past 4-weeks. In individuals with clinically active RA, markers of inflammatory disease activity best explain RA pain with only marginal contributions from QST indices of central sensitisation. Although inflammation plays a key role in the experience of RA pain, the greater proportion of pain severity remains unexplained by DAS28 and ultrasound indices of inflammation.

中文翻译：

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中枢敏化的炎症标志物和定量感觉测试 （QST） 指数对类风湿关节炎疼痛的影响


疼痛是类风湿性关节炎 （RA） 的主要主诉，是多方面的，可能由炎症性疾病活动和中枢敏化驱动。我们旨在确定炎症标志物和中枢敏化的定量感觉测试 （QST） 指数可以解释 RA 疼痛严重程度的比例。这是对临床活动性 RA 患者数据的横断面分析。使用数字评定量表评估疼痛严重程度，并通过 28 关节疾病活动评分 （DAS28） 和超声 （灰度、功率多普勒） 评估炎症。通过“静态”（胫骨前肌或肱桡肌压力痛检测阈值-PPT-TA/PPT-BR）和“动态”（时间求和-TS，条件性疼痛调节-CPM）QST 评估疼痛敏感性。双变量关联使用 Spearman 相关系数，多变量线性回归模型确定对疼痛严重程度的相对贡献。在对 N = 96 （年龄 65 ± 10 岁，77% 女性） RA 患者的双变量分析中，疼痛严重程度与炎症指数 （r = 0.20 至 0.55） 和 CPM （r=-0.26） 显著相关。在包括 TS 、 CPM 、 年龄、性别和体重指数的多变量模型中，炎症指数仍然与疼痛严重程度显著相关。多变量模型解释了 22% 至 27% 的疼痛差异。现在、最强或过去 4 周平均疼痛的子评分与疼痛的关联存在明显的异质性。在临床活动性 RA 个体中，炎症性疾病活动标志物最能解释 RA 疼痛，而中枢敏化的 QST 指数仅占边际贡献。 尽管炎症在 RA 疼痛的体验中起着关键作用，但 DAS28 和炎症的超声指数仍无法解释疼痛严重程度的更大比例。