Is fibromyalgia secondary to rheumatic diseases?

Abstract

Fibromyalgia (FM) affects 2 to 4 % of the population. In rheumatic diseases (RD), the frequency of FM is higher than in the general population, but the question remains whether it is a secondary disease, a complication of RD or an independent comorbid disorder.Objective: to determine whether FM in patients with rheumatoid arthritis (RA) is a secondary or an independent comorbid disorder.Material and methods. The study involved 127 patients who were divided into three groups. Group 1 comprised patients with RA without FM (n=47), group 2 comprised patients with RA + FM (n=55), and group 3 comprised patients with FM without RD (n=25). FM was diagnosed based on the 2016 ACR diagnostic criteria. Pain intensity was assessed using a visual analogue scale (VAS, 10 cm) at rest. We also assessed the frequency of the neuropathic pain using the Pain DETECT and DN4 questionnaires for neuropathic pain, the presence and severity of central sensitization symptoms using CSI, fatigue using FSS, anxiety and depression using HADS, sleep disturbances using the PSQI and cognitive impairment using the DSST. Quality of life (QOL) was assessed using the EQ-5D and the revised FM impact questionnaire – FIQR, in the group of patients without FM, its modified version – SIQR – was used.Results and discussion. Signs of FM preceded the inflammatory changes in the joints and complicated the diagnosis of RA, which was reflected in an increase in the time until RA diagnosis in the RA + FM group to an average of 20 months compared to 10 months in the RA without FM group. No relationship was found between the presence of FM and the degree of RA activity according to DAS28. No specific clinical picture of FM was found in the RA + FM group compared to the FM group without RD.Conclusion. The results obtained suggest that FM in patients with RA is an independent comorbid condition and the cause of various comorbid disorders, which contributes to an even greater impairment of QOL. The diagnosis of FM in patients with RD will optimize treatment: patients suffering from RD and FM require complex therapy.

Keywords

• fibromyalgia
• rheumatoid arthritis
• central sensitization
• comorbidity