Alteration of Thiol-Disulphide Homeostasis in Fibromyalgia Syndrome

Background: Fibromyalgia syndrome (FMS) is an extra-articular rheumatological disease, characterized by widespread pain and somatic symptoms. The etiology has not yet been clarified. Oxidative stress may play an important role in FMS etiology. Thiol group is a very strong antioxidant. We aimed to investigate whether thiol/disulfide homeostasis in FMS is altered or not. Material and methods: A total of 80 female FMS patients and 64 healthy female control individuals were included in this study. Thiol and disulfide values were measured by Erel’s novel methods. Results: Native thiol (330.6 ± 46.1 vs. 356.8 ± 55.5 μmol/L, p = 0.005) and native thiol/total thiol (89.4 ± 3.2 vs. 93.3 ± 4.0, p < 0.001) levels of FMS patients were significantly lower when compared to the values of control group. However, disulfide (19.4 ± 6.3 vs. 12.2 ± 6.3 μmol/L, p < 0.001) levels of FMS patients were significantly higher than healthy individuals. A negative correlation was found between the native thiol/total thiol and fibromyalgia impact questionnaire (FIQ) score among the FMS patients. A positive correlation was found between disulfide values and FIQ score among the patients. Conclusions: In FMS patients, there was a significant correlation between the decrease in the thiol levels and an increase in the disulfide levels with the FIQ scores. We determined that thiol-disulfide rate was deteriorated in FMS patients and it increases in favor of disulfide amounts.