July 8 (UPI) -- Older adults with both hearing and visual impairment have a nearly 90 percent higher risk for developing dementia, according to a study published Wednesday by the journal Alzheimer's and Dementia: Diagnosis, Assessment and Disease Monitoring.
Nearly 30 percent of older adults who suffer from dual sensory impairment were diagnosed with dementia, compared to just over 14 percent of those with no hearing or vision loss, the researchers said.
"Evaluation of vision and hearing in older adults may predict who will develop dementia and Alzheimer's," co-author Phillip H. Hwang, an epidemiologist at the University of Washington School of Public Health, said in a press release.
For the study, Hwang and colleagues enrolled more than 2,000 older adults -- aged 65 and older -- and followed them for eight years. Nearly 23 percent of the study participants had either hearing or visual impairment and just over 5 percent had both, the researchers said.
Over the eight-year study period, dual sensory impairment was associated with an 86 percent higher risk for dementia compared with having no sensory impairments, they said.
The researchers said that 28.8 percent of those with dual sensory impairment were diagnosed with dementia during the study period, compared to 16.9 percent of those with one sensory impairment and 14.3 percent of those with no sensory impairment.
Participants with dual sensory impairment also were twice as likely to develop Alzheimer's disease -- the most common form of dementia -- than those without sensory impairments, the researchers said.
Roughly 6 million American adults have some form of dementia, according to the Alzheimer's Association, while recent estimates suggest that as many as one in five of those 70 and older have dual sensory impairment.
Our findings have "important implications on identifying potential participants in prevention trials for Alzheimer's disease, as well as whether treatments for vision and hearing loss can modify risk for dementia," Hwang said.