Scientists find genetic link between hearing loss and Alzheimer’s
LONDON: Researchers have found genetic links between hearing loss and Alzheimer’s disease, but their finding comes with a catch.
A DNA analysis of hundreds of thousands of people by the QIMR Berghofer Medical Research Institute has found no genetic evidence that hearing loss actually causes Alzheimer’s disease.
Geneticist Michelle Lupton said both traits shared genetic markers associated with inflammation and immune response in the brain.
“What we didn’t find was a causal relationship – the genetic changes that cause hearing loss don’t directly cause Alzheimer’s disease,” Associate Professor Lupton said.
For more than a decade, research has consistently found a strong association between the two conditions.
Such studies have shown that the risk of dementia increases for those with hearing loss, but it has not been clear whether the use of hearing aids would significantly delay the onset of cognitive decline.
“Obviously, we’re not saying that people shouldn’t treat the hearing loss,” Dr Lupton said.
“But from our work, we haven’t shown that hearing loss is a good candidate as a modifiable risk factor for Alzheimer’s.”
She said other studies had found genetic evidence for a stronger causal role between reduced education and Alzheimer’s disease.
Factors such as high blood pressure, high cholesterol, smoking and increased body mass index have also emerged as areas which could be targeted by public health campaigns to potentially reduce the risk of dementia.
PhD candidate Brittany Mitchell, the first author on the hearing loss and Alzheimer’s study, said the research had identified six genes associated with both conditions.
Their findings are published in the journal Alzheimer’s and Dementia: Diagnosis, Assessment and Disease Monitoring.
The research was partly funded by the National Health and Medical Research Council.
