Presbycusis is hearing loss due to the degeneration process in patients over the age of 65 years. This disorder is characterized by decreasing hearing sensitivity in both ears.
Presbycusis risk factors include genetics, aging processes, degenerative diseases, and the environment. Genetic factors inherited for hearing loss is 35-55 percent, and genes known to be associated with oxidative stress due to ROS and atherosclerosis are GSTT1 and GSTM1. Degenerative diseases believed to increase the risk of presbycusis are cardiovascular disease, diabetes mellitus, and chronic kidney disease.
These factors can increase the formation of reactive oxygen species (ROS), which can cause oxidative stress in the cochlea. Oxidative stress causes mutations in mitochondrial DNA and damages cell membranes and nucleic acids.
The damage triggers apoptosis. Components of striatal cells, outer hair cells, and neurons in spiral ganglia can cause cochlear dysfunction, which leads to hearing loss. Audiogram examination in patients with cochlear dysfunction shows an increase in the hearing threshold and is symmetrical.
The increasing number of presbycusis cases along with age indicates the need for prevention efforts to reduce the prevalence of presbycusis in the future. Preventive measures such as limiting calorie intake, magnesium supplementation, and antioxidant administration are believed to reduce the incidence of presbycusis. Provision of antioxidants in several studies showed the most significant results in the prevention of presbycusis.
Prevention efforts by avoiding risk factors for presbycusis are necessary to reduce the number of presbycusis cases in the future. However, the pathogenesis of presbycusis is still unclear.
Reactive oxygen species (ROS) are thought to have an essential role in the pathogenesis of presbycusis. However, knowledge about the role of ROS in the pathogenesis of presbycusis still unknown.
Dr. Nyilo Purnami, dr., Sp.THTKL (K), FICS, and the team conducted research to find out more about the role of ROS in the pathogenesis of presbycusis. So an analytic observational study was conducted with a cross-sectional approach conducted in the Outpatient Unit of Neurotology Division, Geriatric Clinic, Clinical Pathology Installation, and Tissue Bank Installation of Dr. Soetomo General Hospital, Surabaya.
This study involved 50 subjects with presbycusis. The results obtained from the majority of patients aged 70-74 years were 22 patients, and the majority of the sexes were female, 30 patients out of a total of 50 patients. The most common complaint found in 36 patients was hearing loss, followed by 17 patients complaining of difficulty understanding, and sounds heard in 10 patients.
Researchers are also looking for risk factors in patients. It was found that the majority of patients had no family history of similar complaints. Degenerative disease is owned by 36 patients with the highest disease in the form of hypertension and diabetes mellitus.
After measuring ROS plasma levels and a series of related examinations, a correlation striatal between plasma ROS levels and hearing threshold in presbycusis patients with a significant positive-moderate relationship pattern was found. It indicates that the higher the level of ROS in plasma, the higher the hearing threshold.
This study confirms the assumed correlation between plasma ROS levels and the hearing threshold in presbycusis patients. However, the limited studies were caused by intermediate variables that can affect plasma ROS levels such as inflammatory processes, history of antioxidant use, and controlled comorbidities.
Measurement of ROS levels in plasma is still carried out because the measurement of ROS levels in the cochlea is not possible. Spectrophotometry technique is also a drawback of the study because it has sensitivity and specificity compared to luminometry.
Nyilo and team’s study regarding the relationship between plasma ROS levels and the hearing threshold values in presbycusis patients with a significant positive-moderate relationship pattern showed some results. According to her, the higher the level of ROS in plasma, the higher the threshold value in the future. These findings will strengthen the role of ROS in the pathogenesis of hearing loss due to cochlear dysfunction in patients with presbycusis.
In line with the results of previous studies, Nyilo and her team believes her findings can support efforts to prevent presbycusis by avoiding risk factors that can trigger ROS production. Furthermore, advocacy efforts to increase the provision of antioxidants also need to be done to reduce the incidence of presbycusis, for better hearing in old age. (*)
Author: Zahra Safithry Irawan
Details of this research available at http://orli.or.id/index.php/orli/article/view/291
The Correlation Between Plasma Reactive Oxygen Species and Hearing Threshold Levels in Presbycusis Patients
