The Effects of a Continuous Positive Airway Pressure (CPAP) Therapy on Oxidative Stress in Patients with Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a sleep disorder that is prevalent and can have major health consequences. The primary objective of this study was to determine whether oxidative stress is induced in OSA patients. It was further aimed to assess effectiveness of a continuous positive airway pressure (CPAP) therapy on decreasing total oxidant status (TOS) and total antioxidant status (TAS) in OSA patients. This study included 70 patients with sleep disorders. Considering the apnea-hypopnea index (AHI) score confirmed by polysomnography, the subjects were divided into two groups as OSA patients (n = 35) and control group including patients with simple snoring problem (n = 35). OSA patients received a CPAP therapy for one month. Blood samples were collected from both groups of patients to measure TAS and TOS levels before and after the CPAP therapy. TAS and TOS levels were significantly higher (p < 0.001), whereas minimum oxygen saturation (minSpO2) and mean oxygen saturation (meanSpO2) were significantly lower in the OSA patients in comparison to those in the control group (P < 0.001). Positive correlations were observed between AHI and TAS levels as well as between AHI and TOS levels. Moreover, positive correlations were found between TAS and average stress index (OSI), TOS and OSI, as well as between minSpO2 and meanSpO2. In contrast, negative correlations were observed between AHI and minSpO2 and meanSpO2, and between TAS and OSI, minSpO2 and meanSpO2. One month of CPAP therapy in OSA patients caused a decrease in TAS and TOS levels, and an increase in OSI, minSpO2 and meanSpO2 values (p < 0.001). According to the current study, OSA patients have elevated oxidative stress. One month of CPAP therapy seems to have a positive impact on the antioxidant status remarkably, and led to improvement in oxidative stress.