Glutathione Peroxide and Glutathione to Disulfide Glutathione Ratio in Presbycusis: a Case-control Study

BACKGROUND: Presbycusis is a gradual hearing loss caused by the ageing process. This is a chronic condition that affects the elderly population, and sensorineural progressive bilateral symmetry occurs with predominantly high-frequency hearing loss. The ability to discriminate speech decreases; hence, most of the affected patients have conversation problems, especially in noisy environments.This situation is a serious problem among elderly individuals. Social isolation, depression, and paranoia can be related to presbycusis. OBJECTIVE: The aim of this study was to investigate GPx and the GSH:GSSG ratio as risk factors for presbycusis. METHODS: A case-control study was conducted to determine the role of GPx activity with the GSH:GSSG ratio as a presbycusis risk factor in 60 subjects aged 55 to 75 years old during the period of August 2012 - April 2014. All of the subjects passed an ENT examination, pure tone audiometry, and tympanometry. The activity of GPx was measured with the Paglia and Valentine method, and the GSH:GSSG ratio was measured by the calorimetric method. RESULTS: The activity of GPx and the GSH:GSSG ratio were significantly different between the groups (p<0.05), and the odds ratio for high GPx with a low GSH:GSSG ratio was 135 (CI 95%: 5.17–20,028.88). CONCLUSION: High GPx activity with a low GSH:GSSG ratio is a risk factor for presbycusis.