Thiol/disulphide homeostasis as a novel indicator of oxidative stress in sudden sensorineural hearing loss

Objectives: To investigate a novel oxidative stress marker, thiol/disulphide literature homeostasis, in patients with idiopathic sudden sensorineural hearing loss, and to compare the results with healthy controls for the first time. Methods: Thirty-two patients with idiopathic sudden sensorineural hearing loss and 30 healthy individuals were included in the study. Serum native thiol, total thiol and disulphide levels were measured, and disulphide/native thiol and disulphide/total thiol ratios were determined in all subjects. Results: Serum native thiol and total thiol levels were significantly lower in patients with sudden sensorineural hearing loss compared with controls (p < 0.05). Of the 32 patients, 25 had lower native thiol levels than controls (333.2 +/- 73.9 vs 381.8 +/- 35.6 mu mol/l, p = 0.002) and 24 had lower total thiol levels (375.1 +/- 74.3 vs 426.1 +/- 39.3 mu mol/l, p = 0.002). Conclusion: The changes in oxidative markers evident in a significant number of patients may be associated with oxidative stress, which may, in turn, have caused sudden sensorineural hearing loss in those patients.