According to new research, older adults who begin to lose sight and hearing may be at increased risk of developing dementia. The study’s findings were published in the online edition of Neurology, a medical journal of the American Academy of Neurology. The study pointed out that hearing or vision loss is often part of aging, but loss of function in both senses can put you at higher risk for dementia and cognitive decline years later.
However, the study did not find such a link between the loss of only one of these senses. “Depending on the degree of hearing or vision loss, loss of function in your senses can be disturbing and have an impact on your daily life,” said study author JinHyeong Jhoo, Ph.D. Med., From Kangwon National University School of Medicine in Chuncheon, Republic of Korea. Jhoo added: “But the results of our study suggest that the loss of both could be of particular concern.”
The study included 6,520 people between the ages of 58 and 101. Visual and hearing impairments were determined by a questionnaire on the use of glasses or hearing aids. People rated their hearing as “normal”, “reduced but capable of communication without a hearing aid”, “difficult communication with a hearing aid” or “no hearing”. People rated their vision as “normal,” “reduced, but they can watch a newspaper or TV without glasses,” “I can’t watch a newspaper or TV with glasses,” or “they don’t have vision at all”.
At the start of the study, 932 people had normal vision and hearing, 2,957 had vision or hearing impairment, and 2,631 said they had both. Dementia was more than twice as common in the group with both impairments at the beginning of the study. In that group, 201 of 2,631 people, or 8 percent, had dementia at the start of the study, compared with 2.4 percent with single sensory impairment and 2.3 percent without sensory impairment.
Researchers assessed people’s thinking and memory skills every two years for six years using a test that involves remembering and recognizing words. They then analyzed the relationship between hearing or vision impairment and dementia and impairment and dementia. During the six-year follow-up period, 245 people developed dementia. Of the 1,964 individuals with both impairments, 146 developed dementia, compared with 69 of 2,396 individuals with single impairment and 14 of 737 individuals without impairment. In addition, 16 of 142 people who could not determine if they had sensory impairment developed dementia.
After adjusting to factors such as gender, education, and income, the researchers found that a group with hearing and vision impairment was twice as likely to develop dementia than a group with normal sensory function. People with only one impairment were not more likely to develop dementia than those with normal sensory function. In addition, the decline in thinking test scores was steeper among people with hearing and vision impairments.
Jhoo said further research is needed to explain why people with two impairments have a higher risk of dementia than those with one. “Older people with just 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,” Jhoo said.
Jhoo added, “However, when someone has both impairments, it can increase the risk of isolation and depression, which previous research has shown can later affect the risk of dementia and thinking.”
The limitation of the study is that the participants filled in a questionnaire about their hearing and sight. The lack of objective measures for human hearing and vision could have affected the results of the study.
This story was published from the wire agency feed without changes in the text. Only the title has changed.