Could Hearing Aids Help Stave Off Dementia in Older Adults?
RPH Research Foundation funding is being used to help fund ground-breaking research at the Ear Science Institute of Australia. The “HearCog” trial is a two-year randomised control trial of hearing loss and dementia and is now well underway.
Tackling a global health priority, the study is investigating whether hearing aids can delay or arrest cognitive decline. Many studies globally have shown the links between hearing loss and cognitive decline and a landmark report in The Lancet Commission for Dementia(1) showed that hearing loss was a priority for tackling dementia. However, to date, no definitive studies have shown that treating hearing loss will change the trajectory of cognition.
Dr Dona Jayakody, RPH Research Foundation Career Advancement Fellow, is an Audiologist and Research Lead for the Cognition and Hearing Loss Project at Ear Science, who developed the trial concept in 2015 when she began researching the link between cognition and hearing loss.
Dr Jayakody said, “My research found that hearing loss is associated with cognitive impairment/dementia so I was interested in finding out whether this could be delayed or arrested by treating hearing loss. Current data suggests hearing loss accounts for 8% of the modifiable risk factors of all cases of dementia.”
HearCog is a randomised, controlled 24-month clinical trial investigating whether the correction of hearing loss using hearing aids could decrease the 12-month rate of cognitive decline among older adults at risk of dementia. 180 older adults with hearing loss and mild cognitive impairment were recruited to undertake the study.
Although the research results are yet to be finalised, several important issues have emerged during the recruitment phase, and as the study commenced. Participants reported the significant impact that their hearing loss has on loneliness, social isolation, communication challenges and quality of life. Several reported suicidal ideations at the thought of developing dementia.
RPH Research Foundation’s inaugural Innovation and Impact Grant recipient A/Prof Andrew Ford is co-lead of the study and added, “Many things have emerged from this study that we didn’t expect, such as participants wanting to improve their hearing health but having no one to go home to hear with or learn from.”
Study participants completed comprehensive assessments of their hearing, cognitive skills, mental and physical health, and lifestyle. They were all expertly fitted with hearing aids, with some participants waiting a year to receive theirs, as part of the randomised intervention design of the study.
Furthermore, study participants completed Magnetic Resonance Imaging (MRI) and Fluoro-Deoxy-Glucose (FDG)-Positron Emission Tomography (PET) imaging. The results of this imaging will allow researchers to gain more insight into the structural and functional changes of the brain as a result of using hearing aids.
The trial also explores the cost-effectiveness of the intervention as well as the impact of hearing aids on anxiety, depression, physical health, and quality of life.
Hearing loss is the second highest cause of disability in the world, affecting 1.5 billion people with 90% of cases being due to age-related hearing loss(2). Currently, more than 50 million people are living with dementia, an alarmingly growing figure, which is said to triple by 2050(3). Projections suggest that the total number of people living with dementia could be reduced by 13% if the onset of symptoms could be delayed by two years or more(4). A result such as this would not only benefit a huge number of individuals, but significantly reduce the ever-growing financial burden of dementia on our health system.
RPH Research Foundation’s Innovation and Impact Grant 2020 provided funding to help with this critical project. Hearing loss is a concern across Western Australia and there currently is there is no cure or effective treatment currently in sight for dementia. It is hoped the final findings of this project will have significant implications on clinical practice and health policy development worldwide.
References
1. The Lancet study - https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(23)01406-X/fulltext
2. World Health Organisation. Deafness and hearing loss. 2019. Retrieved 17th September, 2019, from https://www.who.int/en/news-room/fact-sheets/detail/deafness-and-hearing-loss.
3. Alzheimer’s Association. 2015 Alzheimer's disease facts and figures. Alzheimer’s Dement. 2015;11(3):332-84. https://doi.org/10.1016/j.jalz.2015.02.003.
4. Vickland V, Chilko N, Draper B, Low LF, O’Connor D, Brodaty H. Individualised guidelines for the management of aggression in dementia - part 1: key concepts. Int Psychogeriatr. 2012;24(7):1112–24. https://doi.org/10.1017/s1041610212000014.
