Hearing Loss May Herald Cognitive Decline

In that dementia and its characteristic cognitive dysfunctions are projected to double every 20 years due to the aging of the worldwide population, identifying the factors in understanding the pathways of this decline are reemerging as a public health focus.  Frank R. Lin, from The Johns Hopkins Center on Aging and Health (Maryland, USA), and colleagues studied 1,984 older adults, average age about 77 years, enrolled in the Health ABC Study, a prospective observational study begun in 1997-1998.  A total of 1,162 individuals with baseline hearing loss had annual rates of decline in test scores that measured global and executive function that were 41% and 32% greater, respectively, than those among individuals with normal hearing. Compared to those individuals with normal hearing, individuals with hearing loss at baseline had a 24% increased risk for incident cognitive impairment, according to the study results. "Our results demonstrate that hearing loss is independently associated with accelerated cognitive decline and incident cognitive impairment in community-dwelling older adults," the authors comment. "The magnitude of these associations is clinically significant, with individuals having hearing loss demonstrating a 30 percent to 40 percent accelerated rate of cognitive decline and a 24 percent increased risk for incident cognitive impairment during a six-year period compared with individuals having normal hearing."