Background Pain represents the cardinal complaint in patients with rheumatoid arthritis (RA). It may reflect inflammation, structural damage, or aberrant processing and regulatory mechanisms.
Objectives We evaluated whether changes in pain reflect inflammatory burden variation or non-inflammatory factors in Latinos with established RA in the United States (US).
Methods We evaluated 271 patients from a single academic center with complete data in parameters of interest on 2 visits, 12 months apart. Demographics, serologies, swollen and tender joint assessments, sedimentation rate, fatigue-VAS (visual analogue scale), pain-VAS, depression assessment (Patient Health Questionnaire-PHQ9), functional disability (Health Assessment Questionnaire, HAQ-DI), presence of erosions and irreversible articular damage (IAD, including subluxation, fusion, arthrodesis, or prosthesis) were recorded. Principal components factor analysis with varimax rotation determined latent variables of symptom change. Multinomial logistic regression modeling with forward stepwise entry determined parameters associated with clinically meaningful change in pain compared to no change
Results Two factors met acceptance criteria (Eigenvalues ≥1) with values of 2.57 and 1.31 respectively (Table 1). Following rotation, factor 1 loadings comprised change in fatigue, pain, depression scores, and functional disability, representing non-inflammatory factors. Conversely, factor 2 encompassed changes in tender and swollen joints and ESR, representing inflammation. Clinically relevant improvement in pain significantly correlated with respective improvements in fatigue, depression, functional disability and tender joints (Table 2); worsening pain was negatively associated with change in disability or fatigue.
Conclusions In Latinos with established RA, change in pain reporting reflects alterations in non-inflammatory parameters such as fatigue, depression and functional disability rather than inflammation. Active screening and consideration of those factors may inform therapeutic interventions, balance patient and physician expectations, and optimize patient satisfaction and clinical outcomes.
Disclosure of Interest None declared