Hearing loss linked to development of dementia

WASHINGTON - A new study has revealed that older adults with hearing loss may be more likely to develop dementia, and their risk increases as hearing loss becomes more severe.

Frank R. Lin, of Johns Hopkins Medical Institutions, Baltimore, and colleagues studied 639 individuals age 36 to 90 without dementia. Participants initially underwent cognitive and hearing testing between 1990 and 1994 and were followed for the development of dementia and
Alzheimer’s disease through May 31, 2008.

Of the participants, 125 had mild hearing loss (25 to 40 decibels), 53 had moderate hearing loss (41 to 70 decibels) and six had severe hearing loss (more than 70 decibels).
uring a median (midpoint) follow-up of 11.9 years, 58 individuals were diagnosed with dementia, including 37 who had Alzheimer’s disease.

The risk of dementia was increased among those with hearing loss of greater than 25 decibels, with further increases in risk observed among those with moderate or severe hearing loss as compared with mild hearing loss.

For participants age 60 and older, more than one-third (36.4 percent) of the risk of dementia was associated with hearing loss.

The risk of developing Alzheimer’s disease specifically also increased with hearing loss, such that for every 10 decibels of hearing loss, the extra risk increased by 20 percent. There was no association between self-reported use of hearing aids and a reduction in dementia or Alzheimer’s disease risk.

The study appears in the February issue of Archives of Neurology, one of the JAMA/Archives journals. (ANI)