Neuropathic pain in rheumatoid arthritis and its association with Afro-descendant ethnicity: a hierarchical analysis

Background: nociceptive pain from joint damage caused by autoimmune inflammatory disease is expected in rheumatoid arthritis. However, neuropathic pain also occurs and persists even with the disease under control. This study aimed to investigate factors associated with neuropathic pain in rheumatoid arthritis by considering sociodemographic and behavioral data as well as lifestyle and clinical aspects in a self-referenced afro-descendant ethnicity sample. Methods: In a cross-sectional study, the Douleur Neuropathique 4, Health Assessment Questionnaire, the Hospital Anxiety and Depression Scale and sociodemographic characteristics were used. Additionally, a Bivariate analysis was performed, followed by hierarchical multiple logistic regression, with results expressed as odds ratio and 95% confidence intervals. Results: the frequency of NP was at a proximal level consisting of clinical characteristics related to anxiety (p=0.03) and depression (p=0.04). When a hierarchical multiple logistic regression analysis was conducted, an independent association was identified between neuropathic pain and black race. At the third and fourth stages, when the clinical variables were adjusted by race, an association was found with moderate functionality (p=0.04) and anxiety (p=0.04). Conclusion: neuropathic pain in rheumatoid arthritis is related to the Afro-descendant ethnicity that affects functionality and anxiety levels.