LAUSR

Rheumatoid Arthritis (RA) is a disabling chronic inflammatory disease that shows an unpredictable and severe clinical course [1]. Global assessment, functional status and disease activity of patients with RA can be influenced also by non-inflammatory factors as concomitant presence of fibromyalgia (FM) [1,2]. FM occur up to 20% in RA patients, who present chronic widespread pain, fatigue and cognitive symptoms that impacts achieving a complete disease remission, having more comorbidities, bearing a higher medical cost and finally exhibiting a worse quality of life [1,3,4]. Range of manifestations of FM varies according ethnical and cultural differences between patients [1]. Here is presented the impact of fibromyalgia in Mexican patients with RA.To determinate the frequency and factors associated to fibromyalgia in Mexican RA patients.624 patients with RA that fulfilled ACR/EULAR 2010 criteria (≥18 years) from a Mexican population recruited from 2012 to 2020 were examined. Patients with or without presence of FM diagnosed by ACR 2010/2011 criteria were included. Demographic factors, clinical features, disease activity measured using DAS28 (Disease Activity Score 28-joint counts), functional status evaluated by HAQ (Health Assessment Questionnaire), comorbidities and pharmacologic treatments were explored for RA patients with and without FM. Charlson’s comorbidity index (CCI) was used to analyze comorbidities. Chi-square, Student´s-t, U Mann-Whitney tests were performed by univariate analysis and logistic regression was executed by multivariate analysis adjusted for age and gender. Statistical tests were conducted at 5% level of significance.Of 624 patients with RA 88.8% were women. The mean age [standard deviation (SD)] was 55.0 (12.3) years. The mean of time at onset of RA (SD) was 11.2 (9.1) years. A total of 311(49.8%) patients had FM; of them 91.6% were women and the mean age (SD) was 54.5 (12.2) years. In the univariate analysis RA patients with FM were more likely to be older and smokers, have seropositive RA, higher body mass index and longer time at onset of RA, show worse functional status by HAQ and more radiographic progression, present more extra-articular and Sicca manifestations, exhibit increased demand of hip and knee arthroplasty, also reveal a higher frequency of comorbidities including depression, osteoporosis and type 2 diabetes mellitus, besides to use a greater number of disease-modifying anti-rheumatic drugs (DMARDs), more biologic agents and higher doses of corticosteroids. Also, CCI was higher in RA patients with FM. Nevertheless, no differences were found for RA disease activity in both groups. In multivariate analysis, higher score of CCI (OR 1.21, 95% CI 1.01–1.44, p=0.037) remained significant in RA patients with FM.This study suggests that RA patients from Mexico have high prevalence of the FM. Those with FM have a worse functional status, a higher frequency and score of comorbidities that impact in a reduction of their quality of life. On the other hand, no differences were found for RA disease activity in both groups. However, these observations must be confirmed in larger and prospective studies.[1]Zhao SS et al. Best Pract Res Clin Rheumatol. 2019;33(3):101423;[2]Duffield SJ et al. Rheumatology (Oxford). 2018;57(8):1453;[3]Kim H et al. Arthritis Care Res (Hoboken) 2017;69(12):1871;[4]Salaffi Fet al. Rheumatol Int. 2017;37(12):2035.None declared