Thiol/Disulfide Homeostasis as a Novel Indicator of Oxidative Stress in Obstructive Sleep Apnea Patients

Abstract

Objectives: The aim of the present study was to assess thiol/disulfide (SS) homeostasis as a novel indicator of oxidative stress in patients with obstructive sleep apnea (OSA) and to investigate the effect of continuous positive airway pressure (CPAP) therapy on oxidative parameters. Study Design: Prospective clinical study. Methods: A total of 104 subjects, 44 in an OSA group and 60 in two control groups (control simple snoring group, control OSA group) were included. The levels of parameters were measured using the Erel and Neselioglu method in patients with moderate or severe OSA before and after CPAP therapy. Results: The serum native thiol (SH) and total SH levels as well as the % SH/total SH ratio were significantly lower (P < 0.05) in OSA patients compared to controls, and the SS level and % SS/SH and % SS/total SH ratios were significantly higher (P < 0.05). After CPAP therapy, the native SH level and % SH/total SH ratio were significantly higher (P < 0.05) than before CPAP therapy, and the SS level and % SS/SH and % SS/total SH ratios were significantly lower (P < 0.05). Significant negative correlations were evident between the apnea/hypopnea index (AHI) and the native SH level and % SH/total SH ratio (P < 0.05) before CPAP therapy; and significant positive correlations were seen between the AHI and the % SS/SH and % SS/total SH ratios but not with the SS level. Conclusion: We found that oxidative stress was increased and CPAP therapy had a positive effect in patients with moderate or severe OSA.