THU0509 The role of thiol-disulfide homeostasis in the etiopathogenesis of fibromyalgia
Authors: E. Sahingoz, B. Nacir, M. Alisik, E. Ogus, O. Erel, H. Genc
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> Fibromyalgia syndrome (FMS) is a chronic disease with unknown etiology, characterised by widespread pain, fatigue, sleep disturbance, cognitive dysfunction and anxiety. Oxidative stress has also been implicated in etiopathogenesis in recent years. <h3>Objectives</h3> In this study we aimed to investigate the role of thiol-disulfide balance in the etiopathogenesis of fibromyalgia, as an indicator of oxidative stress. <h3>Methods</h3> 98 female patients with fibromyalgia, 61 of whom were newly diagnosed and 37 were presently ongoing treatment and 82 healhty female controls were included in the study. Fibromyalgia impact questionnaire, pain visual analogue scale, Pittsburgh sleep quality index, fatigue severity scale, short form-36, tender point count, Beck depression inventory and Beck anxiety inventory were evaluated in both groups. To determine the oxidative balance, the thiol/disulfide balance was investigated by the new automatic measurement method developed by Erel and Neselioglu. <h3>Results</h3> Serum native thiol levels were 394,43±52,43 µmol/L and 418,12±49,95 µmol/L (p=0,002), total thiol levels were 429,55<sup>83,5</sup> µmol/L and 440,95<sup>58,7</sup> µmol/L (p=0,052) and serum disulphide levels were 17,5 (9,8) µmol/L and 14,8 (10,3) µmol/L in the FMS and control groups, respectively (p=0,002). In the FMS group, disulphide/native thiol percent ratios (p&lt;0,001) and disulphide/total thiol percent ratios (p&lt;0,001) were statistically significantly higher while native/total thiol percent ratios (p&lt;0,001) were statistically significantly lower than those of the control group. Serum native thiol levels (p=0.008) were was 384,2 (76,7) μmol/L, 387,6 (65,05) μmol/L and 416,55<sup>63,4</sup> µmol/L; disulfide levels were measured as 17.2 (7.5) μmol/L, 18.3 (14.55) μmol/L and 14.8 (10.3) μmol/L newly diagnosed patients, treated patients and control groups, respectively. Serum native thiol values at the thiol-disulfide balance did not improve disulfide in spite of being slightly approaching the control group in the treated patients. When the ratio of disulfide-native thiol was examined, it was seen that both newly diagnosed and treated patients remained in a balanced disulfide state. There were statistically significantly correlations between tender points (respectively p<i>=0,02</i>, r=-0,241; p<i>=0,039</i>, r=-0,213; p<i>=0,039</i>, r=-0,213; p<i>=0,039</i>, r=0,213), SF-36 pain subscale (respectively p<i>=0,032</i>, r=0,216, p<i>=0,041</i>, r=0,206, p<i>=0,042</i>, r=0,206, p<i>=0,041</i>, r=-0,207) and Beck anxiety inventory scores (respectively p<i>=0,009</i>, r=-0,216, p<i>=0,027</i>, r=-0,225, p<i>=0,026</i>, r=-0,225, p<i>=0,026</i>, r=0,225) with disuphide levels, disulphide/native thiol, disulphide total thiol and native thiol/total thiol ratio. <h3>Conclusions</h3> The disulfide shift of the thiol-disulfide balance and the correlation between the clinical parameters and the thiol-disulfide balance components suggesting the presence of oxidative stress in FMS patients suggests that the role of thiol-disulfide balance in the etiopathogenesis of FMS. <h3>Disclosure of Interest</h3> None declared