Dual Sensory Impairment Increases Risk of Dementia Among Elderly

A combination of vision and hearing loss can put people at greater risk of developing dementia and cognitive decline, according to a new study published by the American Academy of Neurology.

Researchers aimed to “investigate the effects of single sensory impairment and dual sensory impairment on dementia” wrote study author Gihwan Byeon, MD, Kangwon National University School of Medicine, Chuncheon, Republic of Korea, and co-investigators, on the importance of the Korean nationwide, prospective, community-based elderly cohort study.

They analyzed 6,520 elderly individuals between the ages of 58 and 101 using a self-report questionnaire to define visual and auditory sensory impairment.

Nine hundred and thirty-two participants recorded having normal vision and hearing, 2,957 participants reported visual or hearing impairment, and 2,631 participants reported both visual and hearing impairments.

Baseline rates of dementia in patients with dual sensory impairment were more than double the cases seen in other groups, with 201 participants (8%) reported to have dementia. Only 2.4% of participants with one sensory impairment and 2.3% with none reported having dementia at beginning of study. Outcomes were evaluated every 2 years for a period of 6 years.

Six-years following the first report, 245 total participants had developed dementia, including 146 participants of 1,964 with dual sensory impairment, 69 participants of 2,396 with one impairment, and 14 participants of 737 with no impairments.

Dual sensory impairment was significantly associated with increased dementia prevalence. Those with dual sensory impairment were twice as likely to develop dementia (odds ratio 2.17, 95% CI) than those with normal sensory function. Single sensory impairment was not associated with increased dementia prevalence.

“Our results suggest that coexisting visual and hearing impairments facilitate dementia prevalence, dementia incidence, and cognitive decline, but visual or hearing impairment alone do not,” explained Dr Byeon et al.

Further research is needed to see why people with visual and hearing impairments have a greater risk of dementia, researchers concluded.—Erin McGuinness

Reference: Byeon G, Oh GH, Jhoo JH, et al. Dual Sensory Impairment and Cognitive Impairment in the Korean Longitudinal Elderly Cohort [published online ahead of print, 2021 Apr 7]. Neurology. 2021;10.1212/WNL.0000000000011845. doi:10.1212/WNL.0000000000011845