BACKGROUND: Fibromyalgia syndrome (FMS) is a rheumatic disease characterized by diffuse body pain and decreased muscle function. The aim of the present study was to compare the biological rhythms of patients with fibromyalgia syndrome with the biological rhythms of healthy controls.

MATERIAL AND METHODS: This was a cross-sectional, single blind, and single center case-control study. The patients with fibromyalgia were evaluated using a Fibromyalgia Impact Questionnaire (FIQ), Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN) Scale, Visual Analog Scale (VAS), Pittsburg Sleep Quality Index (PSQI) and Beck Depression Inventory (BDI).

RESULTS: The study included 77 female patients with FMS, and 32 healthy female individuals as the control group. We found that the patients in the FMS group achieved higher scores in VAS, BDI, PSQI, and the BRIAN scale than the patients in the control group (P<0.001). An evaluation of the relationship between FMS evaluation parameters and biological rhythm scores in patients with FMS revealed a significant positive correlation between total BRAIN and VAS, FIQ, BDI, and PSQI scores. When the relationship between FMS evaluation parameters and biological rhythm scores was evaluated in patients with FMS, a significant positive correlation was found between total BRAIN and VAS, FIQ, BDI, and PSQI scores (r=0.555, P<0.001; r=0.461, P<0.001; r=0.630, P<0.001; and r=0.551, P<0.001 respectively).

CONCLUSIONS: We consider that an evaluation of the biological rhythm of female patients with FMS, and appropriate treatment when required, would contribute significantly to the treatment and follow-up process of the patients.

Keywords: Fibromyalgia, Myalgia, Questionnaires, Case-Control Studies, Cross-Sectional Studies, Pain, Pain Measurement, Periodicity, Psychiatric Status Rating Scales, Single-Blind Method, Sleep, visual analog scale