Superoxide Dismutase and Glutathione in Otitis Media with Effusion: Relation with Hearing Loss

Objective: To investigate the role of antioxidant defense in otitis media with effusion (OME) and the relation of hearing loss with antioxidant defenses by measuring the concentration of Superoxide Dismutase (SOD) and glutathione (GSH) of both middle ear effusions (MEE) and erythrocytes. Materials and Methods: Twenty-six children with serous otitis media, ages ranging between 4-14 years were prospectively included into the study. A diagnosis of OME was made on the basis of the patient’s history and examination, otoscopy, tympanogram and pure tone audiometry. The MEEs were collected via a sterile, disposable aspirator (Juhn Tym-Tap®, Xomed Inc., Jacksonville, FL 32216, USA) after myringotomy under general anesthesia. After an overnight fast in the morning (08-09 am), blood samples were drawn from patients into tubes with ethylenediamine tetraacetic acid (EDTA) for the measurement of GSH and SOD. Reported values of concentration of Superoxide Dismutase (SOD) and glutathione (GSH) of both MEE and erythrocytes in patients with OME were used as outcome measures. Results: Air-bone gap at 1,000 Hz was positively correlated with MEE SOD activity and GSH content (r=0.584 p<0.01). Airbone gap were found to be negatively correlated with erythrocyte SOD activity and erythrocyte GSH content (r=-0.298 p<0.05). MEE and erythrocyte SOD activities were not, but MEE and erythrocyte GSH concentrations were correlated; r=0.394 (p<0.01) when the two ears were considered together. Age, which was found to be positively correlated with air bone gap values at right ear and left ear was negatively correlated with SOD activity measured in MEEs of left ear (r=-0.628 p<0.01). Conclusions: The positive correlation of both SOD activity and GSH concentration of MEE with hearing loss might represent the potentiation of local defense mechanism against oxidative tissue damage; the positive correlation between effusion and blood GSH values in turn, suggests that systemic GSH supplementation might be beneficial in potentiation of local GSH status.