Two studies presented at the Alzheimer’s Association International Conference (AAIC) 2019 (14–18 July 2019, Los Angeles, CA, USA) demonstrate a link between co-occurring impairments in multiple sensory domains and the risk of dementia.

Philip Hwang and colleagues studied the relationship between combined visual and hearing impairment and dementia risk in 2,052 individuals aged ≥75 years. The researchers found that visual or hearing impairments alone were associated with modest increases (10–11%) in the risk of developing all-cause dementia or Alzheimer disease (AD). However, in individuals with impairments in both sensory domains, the risks of all-cause dementia and AD were increased by 86% and 112%, respectively.

“These findings suggest that co-occurring hearing and vision problems in late life are strongly associated with increased risk of all-cause dementia and AD dementia,” commented Hwang. “Impairment of more than one sense seems to increase risk of dementia synergistically.”

In the second study, Willa Brenowitz, Kristine Yaffe and co-workers examined the relationship between multisensory impairment and dementia risk. The study enrolled 1,810 individuals aged 70–79 years who did not have dementia. The researchers combined measurements of impairments in vision, hearing, smell and touch to generate a multisensory function score — the lower the score, the greater the impairment. The risk of developing dementia over the next 10 years was increased sevenfold in participants in the bottom quartile of sensory function compared with those in the top quartile.

“Our findings suggest that testing for changes in multisensory function may help identify those at high risk for dementia,” said Brenowitz. “Sensory function in multiple domains can be measured during routine health-care visits using non-invasive or minimally invasive tests. In addition, some forms of hearing and vision loss can be treated or corrected, which provides potential opportunities for intervention.”