Presence of Fibromyalgia Syndrome and Its Relationship with Clinical Parameters in Patients with Axial Spondyloarthritis

Background: Fibromyalgia syndrome (FMS) is a disorder with a population prevalence of 1% to 5%. There are insufficient data in the literature on the incidence of FMS in patients with axial spondyloarthritis (SpA), with only a limited number of studies conducted. Objectives: The aim of this study was to determine the presence of FMS in patients diagnosed with axial SpA and to investigate the effect of this coexistence on clinical and laboratory assessments in patients with ankylosing spondylitis. Study Design: This research involved a retrospective analysis of prospectively collected data. Setting: The research took place in an outpatient rheumatology clinic. Methods: This study included 125 patients diagnosed with axial SpA according to the Assessment of Spondyloarthritis International Society criteria. The presence of FMS was investigated according to the 2010 American College of Rheumatology criteria. Pain during activity, resting, and at night was examined using the Visual Analog Scale. Ankylosing Spondylitis Disease Activity Scores were used for assessment of disease activity, Ankylosing Spondylitis Quality of Life Scale was used for quality of life, Bath Ankylosing Spondylitis Functional Index was used for functionality, and Pittsburgh Sleep Quality Index was used for sleep quality. Results: Incidence of FMS was 29.6% in the study population, which consisted of patients who were all diagnosed with axial SpA. Comparison of patient groups with and without FMS revealed no statistically significant differences in age, weight, body mass index, marital status, family history, and smoking history (P> .05), with a higher rate of female patients in the group with FMS at 55% (P < .05). Ankylosing Spondylitis Disease Activity Score-C-Reaktif Protein, Ankylosing Spondylitis Disease Activity Score-Erythyrocyte Sedimentation Rate, Ankylosing Spondylitis Quality of Life Scale, Bath Ankylosing Spondylitis Functional Index, Pittsburgh Sleep Quality Index, and Visual Analog Scale pain scores were significantly higher in the group with FMS (P < .05). Limitation: The study involved a limited number of patients. Conclusions: FMS is observed in one-third of patients with axial SpA. The presence of FMS negatively affects quality of life, functional status, sleep quality, disease activity, and pain level of patients with ankylosing spondylitis. The possibility for coexistence of FMS should be kept in mind when determining the treatment protocols for patients with axial spondyloarthritis, and adjunctive treatment should be given if necessary.