Compensatory paraoxonase and arylesterase levels in hyperbaric oxygen treatment of sudden sensorineural hearing loss

Objective: Paraoxonase1 (PON1) and Arylesterase (ARE) levels are associated with reduced risk of atherosclerosis. The functional status of high density lipoprotein (HDL) is closely related to the PON1/ARE enzyme activity. Functional changes in treatment of sudden sensorineural hearing loss (SSNHL) may be achieved by post-translational modification of lipid metabolism induced by hyperbaric oxygen therapy (HBOT). Methods: Men patients with SSNHL who met the research criteria were included in the study. HBOT was performed on average 30 sessions. Laboratory measurements were made at the beginning and end of HBOT for the same patients. Serum levels of PON1/ARE and routine lipid laboratory parameters were measured to determine possible changes in SSNHL after HBOT. Results: In this study, a reducing effect on PON1 enzyme amount of long-term HBOT was detected. The serum PON1 amount of patients with SSNHL was 19.7 ± 2.7 ng / mL (mean ±} SD) before HBOT, and the serum PON1 decreased to 17.0 ± 2.1 ng / mL (mean ±} SD) after 30 sessions of HBOT. This decrease in PON1 levels was statistically significant (p =0.035). There was also a statistically significant decrease in the enzyme activity of ARE in the SSNHL patients (p=0.024). Conclusion: This preliminary study showed a significant decrease in serum PON1/ARE enzyme content in SSNLH patients with HBOT. In fact, it can be assumed that HBOT has no adverse effect on HDL functionality. However, the decrease in PON1 level by HBOT with 30 or more sessions may be important for the antioxidant function of HDL.It may possibly cause post-translational changes in antioxidant defense mechanisms due to increased oxidative stress with HBOT. In conclusion, larger clinical studies are needed to determine the possible effects of HBOT on HDL-related PON1/ARE functionality in SSNHL.