The risk of incident Alzheimer's disease also increases with severity of baseline hearing loss
TUESDAY, Feb. 15 (HealthDay News) -- Hearing loss is independently associated with incident all-cause dementia and Alzheimer's disease, according to a study published in the February issue of the Archives of Neurology.
Frank R. Lin, M.D., Ph.D., from the Johns Hopkins School of Medicine in Baltimore, and colleagues prospectively followed 639 participants aged 36 to 90 from the Baltimore Longitudinal Study of Aging who were dementia free between 1990 and 1994. Of the participants, 455 had normal hearing (less than 25 dB), 125 had mild hearing loss (25 to 40 dB), 53 had moderate hearing loss (41 to 70 dB), and six had severe hearing loss (more than 70 dB) in the better-hearing ear. Time to incident dementia was analyzed according to the severity of hearing loss and adjusted for variables.
The investigators identified 58 cases of incident dementia, of which 37 patients were diagnosed with Alzheimer's disease during an average of 11.9 years follow-up. The severity of baseline hearing loss showed an increase in the risk for all-cause dementia (1.27 per 10 dB loss). The risk of incident all-cause dementia increased with the severity of hearing loss (hazard ratios, 1.89, 3.0, and 4.94 for mild, moderate, and severe hearing loss, respectively) compared to normal hearing. The risk of incident Alzheimer's disease increased with baseline hearing loss severity (1.20 per 10 dB loss).
"If confirmed in other independent cohorts, the findings of our study could have substantial implications for individuals and public health," the authors write.
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