The Oxidant–Antioxidant Equilibrium in the Blood of People with Sudden Sensorineural Hearing Loss After the First Hyperbaric Oxygen Therapy Session – A Preliminary Study

The activity of selected antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) in erythrocytes, and the concentration of thiobarbituric acid reactive substances (TBARS) in blood plasma and erythrocytes, were determined in people subjected to hyperbaric oxygen (HBO) therapy due to sudden sensorineural hearing loss (SSNHL). Venous blood samples were taken immediately before entering the hyperbaric chamber and 5 min after leaving it. In the study group, two age subgroups were distinguished: group I consisting of subjects under 35 and group II consisting of subjects over 50. The obtained values were analysed statistically using Student’s t-test. Differences were considered as statistically significant at p < 0.05. A statistically significant decrease in the CAT activity was shown 5 min after leaving the hyperbaric chamber in pooled subjects (p < 0.01) and group I (p < 0.05). Furthermore, a statistically significant decrease in the erythrocyte TBARS concentration was observed in group II (p < 0.05). It was demonstrated that a single exposure to hyperbaric oxygen affects the oxidant-antioxidant equilibrium as evidenced by, e.g., a statistically significant decrease in the activity of catalase in erythrocytes. It is possible that the antioxidant response to HBO depends on the age of subjects.