Comorbid fibromyalgia amplifies disease activity in patients with rheumatic disorders
Fibromyalgia occurs commonly in patients with rheumatoid arthritis (RA), axial spondyloarthritis (AxSpA) and psoriatic arthritis (PsA), with disease activity seemingly greater in the presence of fibromyalgia, a study reports.
Researchers accessed multiple electronic databases for studies reporting the number of fibromyalgia diagnosis in patients with a pre-existing diagnosis of RA, AxSpA or PsA. They used proportional and pairwise meta-analysis methods to evaluate data.
Pooled data from 40 studies revealed that the prevalence rates of fibromyalgia were 21 percent in RA, 13 percent in axSpA and 18 percent in PsA. Comorbidity with fibromyalgia was associated with higher disease activity score (DAS) in patients with RA and ankylosing spondylarthrosis (RA: DAS28 mean difference, 1.24; 95 percent CI, 1.10–1.37; AS: BASDAI mean difference, 2.22; 1.86–2.58). This was also true for PsA patients.
Of note, the presence of fibromyalgia correlated with increased self-reported, rather than objective, components of DAS (eg, tender joint count and visual analogue scale (VAS) pain scores).
Researchers pointed out that the differences in fibromyalgia prevalence rates between diseases might reflect the varying proportions of gender found naturally for each condition. For example, RA is common in women, PsA affects men and women almost equally, and AS is found predominantly in men. Fibromyalgia, on the other hand, is strongly associated with female sex and as such corresponds to the relative prevalence estimates found in these inflammatory disorders.
Also, the present data underscore the limitations of using disease activity indices alone in assessing inflammatory activity in rheumatic patients with fibromyalgia, researchers added. Thus, it is important that clinicians interpret these scores in conjunction with knowledge of the presence of fibromyalgia for optimal management and appropriate drug treatment.