Cognitive decline ranges in severity from mild cognitive impairment (MCI) to Alzheimer’s disease and related dementias (ADRD). It is marked by memory loss and difficulty thinking and making decisions. Cognitive decline is a significant, common challenge to older adults’ well-being and their ability to live independently.
Today, cognitive impairment and ADRD are major global public health and social concerns as the population of older adults rises around the world. By 2050, more than 152 million people will be affected by these conditions. That’s why many countries, including the United States, see the prevention of ADRD as a key public health priority and are studying programs to help stem these diseases.
One way to prevent cognitive impairment and ADRD is to treat the problems that raise the risk for developing them. Two of these risk factors are hearing and vision loss. Currently, about 60 percent of people aged 70 years or older are affected by hearing loss, 40 percent are affected by vision loss, and 23 percent of older adults have both vision and hearing loss. Some studies have suggested that having both hearing and vision loss may be linked to poorer cognitive function or to a faster rate of cognitive decline.
However, more specific studies are needed to obtain more accurate information about these two sensory problems and their relationship to cognitive decline, suggests a research team that examined the associations between having loss of one sensory function — hearing or vision — and cognitive decline, as well as the associations between having both types of sensory loss and cognitive decline. They published their findings in the Journal of the American Geriatrics Society.
The Aging, Demographics, and Memory Study (ADAMS) is a study focused on dementia among older adults age 70 or older. In the ADAMS study, researchers have measured the cognitive function of participants aged 65 and older every two years since 1992. They used an interview process to test cognitive status. The cognitive status test contains sections that measure immediate and delayed word recall, serial subtraction, counting backward, orientation to time, object naming, and naming the president/vice president. The test is administered by telephone or face-to-face interviews.
The researchers also administered tests to measure the extent of hearing and vision loss for this particular study. Dual sensory loss was defined as having both hearing and vision loss.
Among the participants tested:
- 44 percent had hearing loss
- 39 percent had vision loss
- 19 percent had dual sensory loss
The average age of participants was 81 years old, and a little more than half of them were women.
The researchers reported that older adults with hearing loss had a much faster rate of cognitive decline as they aged than older adults with normal hearing. Having both vision and hearing loss worsened cognitive decline as people aged, and that decline was more severe than the decline for hearing loss on its own. Older adults with vision loss did not have a faster rate of cognitive decline than older adults with normal vision.
This summary is from “Longitudinal Association between Hearing Loss, Vision Loss, Dual Sensory Loss, and Cognitive Decline.” It appears online ahead of print in the Journal of the American Geriatrics Society. The study authors are: Shaoqing Ge, PhD, MPH; Eleanor S. McConnell, PhD, MSN, RN; Bei Wu, PhD; Wei Pan, PhD; XinQi Dong, MD, MPH; and Brenda L. Plassman, PhD.