The researchers behind an early-stage, preprint study have claimed it points to a potential vascular pathway connecting hearing loss and cognitive decline.
They also claimed their findings supported hearing loss as a modifiable contributor to cognitive decline and dementia.
The population-based study from Germany, published as a preprint through The Lancet’s Social Science Research Network (SSRN collaboration)*analysed data from 4,420 adults aged 20 to 84 years participating in the Study of Health in Pomerania (SHIP-TREND).
The SSRN collaboration is an online repository where early-stage, non-peer-reviewed medical research is shared publicly before formal publication.
While the findings have not yet been peer reviewed, the authors said the scale and inclusion of brain imaging offered new insight into how auditory health may intersect with cognitive decline.
Of the participants,1,455 reported some degree of hearing loss, with 679 describing it as clinically significant. Tinnitus was reported by 874 people.
Cognitive performance was assessed using tests of verbal memory and executive function, while a subset of 2,144 participants underwent MRI scans to evaluate brain structure, including regional brain volumes and cortical thickness.
The analysis found that self-reported hearing loss was associated with poorer memory performance and structural brain differences, particularly in areas involved in auditory processing and regions linked to cognition and Alzheimer’s disease.
The researchers said that changes in white matter – specifically increased white matter hypointensity volume – partially explained the relationship between hearing loss and immediate memory recall, accounting for nearly 9% of the association.
Lead authors suggested this finding pointed to a potential vascular pathway connecting hearing loss and cognitive decline. White matter changes were often associated with cerebrovascular disease, raising the possibility that hearing impairment may either reflect or contribute to broader vascular processes affecting the brain, they said.
“This large cohort study not only confirmed independent associations of self-reported hearing loss with memory performance and structural brain measures but also suggested a pathophysiologic link between hearing loss and cerebrovascular disease,” they wrote.
“Our findings support hearing loss, but not tinnitus, as a modifiable contributor to cognitive decline and dementia.”
Tinnitus alone was not associated with cognitive performance or adverse brain measures, they said.
Although hearing loss and tinnitus frequently co-occurred, with people with hearing loss being more than seven times more likely to report tinnitus, the study found no evidence of a combined or additive effect on cognition or brain structure.
The authors cautioned that the cross-sectional design limited conclusions about causality. It remained unclear whether hearing loss directly contributed to brain changes and cognitive decline, or whether shared underlying processes drive both, they said.
As a preprint, the study has not undergone peer review and should not yet inform clinical decision-making, they said.
*Preprints with The Lancet is a collaboration between The Lancet Group of journals and SSRN to facilitate the open sharing of preprints for early engagement, community comment, and collaboration. SSRN said the preprints were not Lancet publications or necessarily under review with a Lancet journal. They were early-stage research papers that had not been peer-reviewed. SSRN said findings should not be used for clinical or public health decision-making or presented without highlighting these facts.
