The risk of hearing loss (HL) and sensorineural hearing loss (SSNHL) in young adults rose after COVID-19 infection from 2020 to 2022, according to a study by South Korean researchers, who urge cautious interpretation of the results due to a lack of objective audiologic data and other limitations.
The team analyzed data on 6.7 million adults aged 20 to 39 years without a history of HL from the Korea Disease Control and Prevention Agency–COVID-19 National Health Insurance Service from January 2020 to December 2022. The average participant age was 29.6 years, 49.0% were men, 72.0% had COVID-19, and 93.1% had completed the primary COVID-19 vaccination series at baseline.
HL was diagnosed when a participant heard sounds at or above 25 decibels (dB) only, based on the average pure-tone hearing threshold of 0.5, 1, 2, and 4 kilohertz. The diagnostic criteria for SSNHL were a rapid progression of COVID-19 within 72 hours with a HL of 30 dB or more at three consecutive frequencies.
The research was published yesterday in eClinicalMedicine.
"Recent case reports have documented sudden HL in young adults with no prior hearing issues after COVID-19 infection, suggesting that hearing problems among young individuals have emerged as a new public health issue following the COVID-19 pandemic," the study authors wrote. "HL in young individuals can significantly impact their quality of life, academic and occupational performance, and social functioning."
Hearing issues 3 times more common post-COVID
There were 38,269 HL cases and 5,908 SSNHL cases during the study period. The risk of HL was higher in the COVID-19 cohort than in the uninfected group (incidence, 11.9 vs 3.4 per 10,000 person-months [PMs]; subdistribution hazard ratio [SHR], 3.51; dyslipidemia-adjusted SHR [aSHR], 3.44), as was the risk of SSNHL (incidence, 1.8 vs 0.5 per 10,000 PMs; SHR, 3.58; aSHR, 3.52).
These findings suggest that healthcare providers should be aware of the increased risk of hearing impairments in young adult COVID-19 patients and consider appropriate screening and follow-up.
A sensitivity analysis showed that the rate of HL and SSNHL was higher in patients who had undergone a health screening exam than in the rest of the study population. Similar to the findings of the primary analysis, an analysis of the health-screening cohort linked COVID-19 to higher risks of HL (aSHR, 3.55) and SSNHL (aSHR, 3.43).
A stratified analysis showed that the highest risk of COVID-related HL was seen in young adults with diabetes (aSHR, 4.12), and the highest risk of SSNHL was also in those with diabetes (aSHR, 4.44), followed by those with abnormal cholesterol levels (aSHR, 4.25).
No significant interaction was found for COVID-19 vaccination in evaluating the association of COVID-19 and the risk of HL or SSNHL by vaccination status.
Need for hearing screenings
"These findings suggest that healthcare providers should be aware of the increased risk of hearing impairments in young adult COVID-19 patients and consider appropriate screening and follow-up," the researchers wrote. "Additionally, these results may inform public health policies regarding COVID-19 management and vaccination strategies, emphasizing the importance of protecting young adults from infection to prevent potential long-term auditory complications."
"Due to study limitations, including the lack of objective audiological data, issues with generalizability to other populations, and the retrospective design, careful interpretation is necessary," they added.
The team called for future studies using objective audiologic data and a longer follow-up period and those designed to delve into the biologic mechanisms behind SARS-CoV-2's effects on hearing and into potential treatments for hearing loss.
