the Deafness old age It’s more of a nuisance than a serious health problem. Well, it’s time to dismiss this idea because, among other things, it appears to be the single most important avoidable risk factor for developing Alzheimer’s disease.
As is known, the consequencesThis disease It is devastating. There is a gradual loss of memory and the ability to think, which eventually affects behavior and personality. Life expectancy is reduced and autonomy disappears. The individual, family, social and economic collapse is very serious.
As the population ages and life expectancy increases, the impact of Alzheimer’s disease is increasing. Some are diagnosed every year. Ten million cases worldwideThe number of people affected is estimated at The number will rise from 1,000,000 in 2025 to 1,700,000 in 2050 in Spain alone.That is why every advance in understanding its causes is a step towards improving the quality of life of people who suffer from it and also towards a cure.
Waste accumulation
In Alzheimer’s disease, basic mechanisms fail to stabilize and recycle certain proteins in brain cells, which are like building blocks for their survival. When these mechanisms fail, remnants of the defective clumps accumulate in the brain, which are true “protein debris.”Since the German scientist noticed them. Alois Alzheimer At the beginning of the twentieth century, they allowed the disease to be recognized.
These residues—clumps of hyperphosphorylated tau protein inside cells and plaques of beta-amyloid protein—damage neural circuits and block signal transmission. This results in memory loss, inability to solve problems, depression, behavioral changes, and personality disintegration.
Total risk
It is not known why these basic cellular mechanisms fail. It appears to be due to a combination of several environmental factors, acting on genetic predisposition conditions, but the results are not yet conclusive. In The Lancet, A panel of experts periodically analyses the risk factors for dementia.According to the latest estimates, genetic factors account for 55% of the risk. The other 45% consists of fourteen environmental factors that operate throughout life. Of these, adult-onset deafness is prominent.
This is how deafness develops
Deafness due to age begins after the age of 50. It affects Up to 40% of people over 65 and 80% of people over 80.
First, they stop hearing high-pitched sounds, an early stage in which hearing loss usually goes unnoticed. As the disease progresses, people stop hearing more serious sounds, which include many word sounds. That’s when the problem begins to be discovered.
At this stage, the use of hearing aids slows down the process, as the receptor cells in the inner ear are mainly damaged. These are microscopic antennae that receive sound, amplify it and convert it into electrical signals that are transmitted to the brain. Hearing aids amplify sound where damaged cells cannot. But the brain’s auditory circuits are also affected. So amplification with hearing aids doesn’t help much: the auditory signals, even if amplified, are not transmitted properly through the damaged cables. This creates serious communication problems that lead to withdrawal, isolation, anxiety and even depression..
You need to be aware
Although the idea that the impact of deafness is relatively low persists, several reports in The Lancet suggest that eliminating deafness would reduce new cases of dementia by 7% to 9%—high values that were unknown before these works were published.
Health professionals and the general public need to become aware of this issue. In the field of dementia prevention and care, deafness due to old age is still underestimated in the face of other risks. A recent publication shows that l“Amplification with hearing aids alleviates cognitive impairment in at-risk older adults.”.
Actions to prevent age-related hearing loss should be prioritized. For example, it cannot be neglected. The relationship between adult deafness and noise exposure in early lifeDecisive educational interventions are needed.
vicious circle
However, in addition, it is necessary to investigate the biological mechanisms involved in the association between hearing loss and Alzheimer’s disease. In this context, our research team explored whether The disease itself accelerates the onset of deafness, which can lead to a vicious cycle..
To find out, we use animal models that reproduce the features of deafness during aging and, at the same time, neurodegenerative diseases. In this way, we verify that when we experimentally induce manifestations of Alzheimer’s disease, hearing problems appear earlier. This suggests the existence of a vicious circle.
Why might this happen? In the inner ear, there are cells that act like an electric battery: they supply the receptor cells, the “antennae,” with the energy needed to generate auditory signals and send them to the brain.
The area of the inner ear where the “battery cells” are located contains a large number of small blood vessels. During aging, cells of the body’s rapid defense system against aggression appear: inflammation. According to our observations, inflammatory cells will be more numerous and active in mice with features of Alzheimer’s disease.
As we age, these defense mechanisms spiral out of control and end up damaging other cells, with the added bonus that Alzheimer’s can increase inflammation and worsen the “batteries” of the inner ear. This can accelerate deafness, which in turn exacerbates the neurodegenerative disease. Studying the relationship between hearing loss and Alzheimer’s could open up new avenues for improved prevention and treatment.
José M. Juiz, as principal investigator, and his team receive competitive public funds to develop their research activity, coming from the State Plan for Research and Development through the Research Agency of the Spanish Ministry of Science and Universities and the Regional Research and Development Agency. +Plan of the Government of Castilla-La Mancha through its Regional Research Agency. He does not receive a salary, consultancy, own shares or receive funding from any company or institution that could benefit from this article, and he has declared that he has no relevant relationships beyond the academic position stated. This article was originally published in Conversation.
“Infuriatingly humble social media buff. Twitter advocate. Writer. Internet nerd.”
