Hearing loss and dementia share a common trait – a gradual onset that often leads people to overlook symptoms until they advance. However, recent research has illuminated a strong link between these conditions, even though hearing loss is a natural part of aging, while dementia is not.
The Framingham Heart Study.. highlighted a connection between hearing loss and cardiovascular disease. In a 2009 paper, Dr. David R. Friedland, a professor of otolaryngology at the Medical College of Wisconsin in Milwaukee, postulated that low-frequency hearing loss could serve as an early indicator of vascular problems. The sensitivity of the inner ear to blood flow allows for early detection of vascular changes, possibly preceding other bodily signs.
A study by Johns Hopkins and the National Institute on Aging underscores the likelihood of hearing loss contributing to dementia development. This study examined risk factors associated with dementia:
- High blood pressure
Dr. Frank Lin MD, PhD, an assistant professor in the Division of Otology at Johns Hopkins University School of Medicine, emphasized the strong link between hearing loss and dementia. However, the interplay between otologists and geriatricians has been limited, causing uncertainty about the relationship between the two conditions.
Dr. Lin's team reviewed data from the Baltimore Longitudinal Study on Aging(BLSA)), a long-term study initiated by the National Institute on Aging in 1958. The study tracked thousands of individuals with diverse medical conditions over several decades.
A subsequent study, published in the February 2013 Archives of Neurology, concentrated on 639 participants from the Baltimore Longitudinal Study on Aging. Over a span of four years (1990-1994), researchers evaluated their hearing and cognitive abilities. At the study's outset, a quarter of participants exhibited some degree of hearing loss, and none had dementia.
Over the ensuing 18 years, 58 out of the 639 participants developed dementia. The study found that those with hearing loss at the study's commencement were significantly more prone to developing dementia. Conversely, participants with normal hearing faced lower dementia risk. Severity of hearing loss—mild, moderate, or severe—was proportionally linked to an increased risk of dementia. Astonishingly, many people delay treating hearing loss for up to two decades.
George Gates, M.D., a hearing expert at the University of Washington in Seattle, corroborated this connection. He emphasized, "We listen with our ears but hear with our brains. It is simply not possible to separate audition and cognition."
Given challenges in hearing aid adherence, combined with the rise of online and discount store purchases, follow-up care is often inadequate. Millions of Americans have impaired hearing, and predictions suggest that by 2050, 1 in 30 will develop dementia. Effective hearing loss treatment may significantly impact dementia progression.
Caregiver Tip: Incorporate audiological exams into annual physicals and promote hearing aid use, potentially slowing dementia decline. Keep in mind that dementia patients may not accurately respond to mental status exams due to hearing limitations. Discuss this with healthcare providers.
For further information, please visit the John Hopkins Study.