Abstract
This study aimed to identify risk factors of nociplastic pain in patients with autoimmune arthritis. Patients suffering from chronic pain and autoimmune arthritis were invited to participate in a study via moderated support groups on social media. Each invitation included a brief description of nociplastic pain. The study cohort comprised 185 patients, primarily those with rheumatoid arthritis (64%) and spondyloarthropathies (27%). 82% of patients scored positively (≥ 40 points) on the Central Sensitization Inventory (CSI), while 57% showed a neuropathic component as indicated by the PainDetect Questionnaire (PDQ). Of the participants with a positive CSI score, 86% achieved at least a borderline grade on the PDQ. More frequent use of painkillers (> once a day) correlated with higher CSI scores (mean difference (MD) = 7.1, p = 0.039, and MD = 8, p = 0.005 compared to daily and less frequent use, respectively). In a multivariable linear regression model, factors such as depression (β = 8.7, p < 0.001), nocturnal pain (β = 4.5, p = 0.013), need for painkillers (β = 5.3, p = 0.032), disease duration > 2 years (β = 3.3, p = 0.036), Chronic Pain Grade Scale (β = 2.8, from I to IV grade, p < 0.001), and worse mood (β = -0.9, on a 0-10 scale, p = 0.031) were independently associated with higher CSI scores. Nocturnal pain and pain-related disability may serve as clinical risk factors of nociplastic pain. The PDQ may lose its reliability in detecting neuropathic pain in patients with a high nociplastic component.