Another Large Study of Hearing Aid Use Shows Deafness Increases Dementia Risk

You might compare the research noted here with another similar study published a year ago. In both cases, data on hearing aid use in large patient populations is used to demonstrate that hearing loss contributes to the onset and progression of dementia. This data doesn't favor any specific theory regarding the mechanism, such as atrophy of brain structures resulting from disuse versus some form of maladaptive compensatory activity in the brain. Greater understanding of the mechanisms involved will require further research.

Hearing loss has been suggested as a risk factor for dementia, but there is still a need for high-quality research to better understand the association between these two conditions and the underlying causal mechanisms and treatment benefits using larger cohorts and detailed data. This population-based cohort study was conducted in Southern Denmark between January 2003 and December 2017 and included all residents 50 years and older. We excluded all persons with dementia before baseline as well as those who did not live in the region 5 years before baseline, with incomplete address history, or who had missing covariate information.

The study population comprised 573,088 persons (298,006 women [52%]; mean [SD] age, 60.8 [11.3] years) with 23,023 cases of dementia and mean (SD) follow-up of 8.6 (4.3) years. Having a hearing loss was associated with an increased risk of dementia, with an adjusted hazard ratio (HR) of 1.07 compared with having no hearing loss. Severe hearing loss in the better and worse ear was associated with a higher dementia risk, with an HR of 1.20 and 1.13, respectively, compared with having no hearing loss in the corresponding ear. Compared with people without hearing loss, the risk of dementia was higher among people with hearing loss who were not using hearing aids than those who had hearing loss and were using hearing aids, with HRs of 1.20 and 1.06, respectively.

The results of this cohort study suggest that hearing loss was associated with increased dementia risk, especially among people not using hearing aids, suggesting that hearing aids might prevent or delay the onset and progression of dementia. The risk estimates were lower than in previous studies, highlighting the need for more high-quality longitudinal studies.

Link: https://doi.org/10.1001/jamaoto.2023.3509