A new study conducted by scientists as Johns Hopkins School of Medicine and the National Institute on Aging has found a correlation between hearing loss and development of Alzheimer’s Disease.
“This work suggests that there is a strong predictive association between hearing loss as an adult and the likelihood of developing cognitive decline with aging,” said study lead author Dr. Luigi Ferrucci, who is chief of the U.S. National Institute on Aging’s Longitudinal Studies Section, as well as director of the Baltimore Longitudinal Study of Aging.
The study, called “Hearing Loss and Incident Dementia,” is published in the February, 2011 issue of the Archives of Neurology journal.
The research was conducted over a four-year period, on 639 men and women between the ages of 36 and 90, none of whom had dementia at the start of the study in 1990. The participants were tracking for an additional average of 12 years for signs of dementia/ Alzheimer’s.
By cross-referencing data on those who developed mild, moderate or severe hearing loss with data on those diagnosed with dementia or Alzheimer’s, the researchers found that mild hearing loss was linked to a slight increase in dementia risk, but the risk increased noticeably among those with moderate and severe hearing loss.
For participants 60 and older, more than 36 percent of dementia risk was linked to hearing loss, the authors reported.
The worse the hearing loss, the worse the risk for Alzheimer’s as well. For every additional loss of 10 decibels of hearing capacity, Alzheimer’s risk appeared to go up by 20 percent, the researchers said.
Based on the study results, the authors called for further research, including investigation into whether correction of hearing loss, for example, by means of hearing aids and surgery, could potentially reduce dementia risk.
However, Dr. Ferrucci cautioned that it is premature to draw any conclusions. “But as a scientist I cannot yet say that curing hearing loss will prevent dementia,” he said. “We have now opened a window on this association. But there is still a lot of work to be done before we can be sure there is actually a causal relationship.”
Some scientists postulate that advancing age is the strongest predictor of both hearing loss and development of dementia. Others suggest that hearing loss may indicate damage to nerve cells, which could also cause or be caused by developing dementia. Still others suggest that the association may arise from the fact that hearing loss is very socially isolating, which also is associated with accelerated cognitive decline due to lack of cognitive stimulation.
Read more in the HealthDay article published by MedlinePlus » Study Suggests Hearing Loss-Dementia Link: MedlinePlus.
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