Hearing loss ups Parkinson’s risk but hearing aids may reduce risk, study finds

Hearing loss may raise the risk for Parkinson’s disease but getting hearing aids could help lower this risk, a new study finds.

The report was published Monday in JAMA Neurology.

Researchers analyzed the electronic health records of more than 3.5 million US veterans, who had an audiogram, and followed up on the participants (the average follow up time was 7.6 years). They noted which people had hearing loss and Parkinson’s disease at the start of the study, and how many were diagnosed with the disease over the course of the follow-up period.

At the time of their hearing test, 20.8% had normal hearing. Of those with hearing loss, 30% had mild loss, 28.9% had moderate loss, 15.8% had moderate to severe hearing loss, and 4.3% had severe to profound hearing loss. Most of the participants (96%) were male, and their average age at the start of the study was 67.

Ten years after that initial test, the team found that hearing loss increased the risk of developing Parkinson’s disease. They found 6.1 additional cases of Parkinson’s among those with mild hearing loss; 15.8 additional cases among those with moderate loss; 16.2 among people with moderate to severe loss, and 12.1 additional cases among veterans with severe to profound hearing loss.

They also found that veterans with mild hearing loss had a greater cumulative incidence of Parkinson’s compared with those who had normal hearing at five 10, 15 and 20 years after the first audiogram.

In general, the greater the hearing loss, the higher the risk of developing Parkinson’s later in life, the authors wrote.

However, when people were given hearing aids promptly, the cases of Parkinson’s went down by 21.6 cases per 10,000 people.

While no previous study has confirmed this finding in people with Parkinson’s disease, another study found similar results in people with dementia, the authors noted.

Though the research didn’t study the mechanisms behind how hearing loss could increase a person’s risk for Parkinson’s, the authors theorized that hearing loss may play a role in neurodegeneration.