WEDNESDAY, April 7, 2021 (HealthDay News) – The combination of hearing and vision loss is associated with an increased risk of mental decline and dementia, but only one of these impairments is not associated with a higher risk, New South Finds Korean Study.
It is not clear why reducing both senses, but not just one, would increase the risk of dementia, but the leader of the study had a theory related to the importance of socializing in keeping the brain sharp.
“Older people with only visual or hearing impairment can usually still maintain social contact, so they may not feel as isolated or depressed as people who have both impairments,” said Dr. Jin Hyeong Jhoo of Kangwon National University School of Medicine in Chuncheon.
“However, when someone has both impairments, it can increase the risk of isolation and depression, which previous research showed could later affect the risk of dementia and thinking,” Jhoo explained.
A new study published online on April 7 in Neurology, included 6,520 people, ages 58 to 101, whose visual and hearing impairments were assessed by asking questions about the use of glasses or hearing aids.
At the start of the study, 932 people had normal vision and hearing, nearly 3,000 had vision or hearing impairment, and just over 2,600 had both.
In addition, the researchers also found that at the beginning of the study, dementia was more than twice as common among people with both impairments (8%) than among those with single impairment (2.4%) or no impairment (2.3%).
Participants’ memory and thinking skills were also assessed every two years for six years. During that time, 245 people developed dementia. Of the nearly 2,000 people with both disabilities, 146 developed dementia, compared with 69 of about 2,400 people with one disability and 14 of 737 people without the disability.
After adjusting to factors such as gender, education, and income, the researchers concluded that people with hearing and vision impairments were twice as likely to develop dementia than those with one or no impairments.
The researchers also found that people with hearing and vision impairments had a higher drop in thinking test scores.
“Depending on the degree of hearing or vision loss, the loss of function in your senses can be disturbing and have an impact on your daily life,” Jhoo said in a magazine statement. “But the results of our study suggest that the loss of both may be of particular concern.”
One expert from the United States said the study, however, left many questions unanswered. Darius Kohan directs otology and neurotology at Lenox Hill Hospital and Manhattan Eye, Ear and Throat Hospital, both in New York City. Reviewing the findings, he said the study was weakened by the fact that it relied on people’s “self-reports” of vision or hearing loss (not a clinical examination).
Also, it is not clear how many findings could be translated to the non-Korean population. “One limitation they do not address is the social / cultural differences in South Korea compared to other countries / cultures in the interaction of family and society with their older population,” Kohan said.
Finally, he said that in the United States and around the world, hearing loss is associated with increased chances of a decline in cognitive abilities.
“There are numerous studies around the world that document that hearing loss in the elderly promotes isolation, reduces communication and withdrawal from interaction with others, which leads to a disproportionate cognitive decline,” Kohan said.
The American Academy of Family Physicians talks more about dementia.
SOURCES: Darius Kohan, dr. Med., Director of Otology / Neurotology, Lenox Hill Hospital and Manhattan Eye, Ear and Throat Hospital, New York; Neurology, news release, April 7, 2021