Hearing Impairment as a Risk Factor for Dementia in Older Adults

Study Overview
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Brief Summary
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This Doctor of Philosophy (PhD) project is part of a larger project on potentially modifiable risk factors for dementia in a life course perspective, with an overarching aim to improve prevention of dementia and thereby potentially relieve patient and caregiver distress and decrease societal load. The present PhD project will concentrate on confirming knowledge of HI as an independent risk factor for dementia and exploring potentially causative factors to explain this relationship.

Detailed Description
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Despite a huge increase in the knowledge about disease mechanisms in various types of dementia in recent years, no curative treatment exists at present. Results from research on disease-modifying agents have been disappointing. This has led to an increased interest in other ways to reduce the prevalence of dementia. A recent report estimated that up to one third of dementia cases could be delayed or prevented by interventions directed at the most common risk factors. In the Lancet commission on dementia prevention, treatment, and care, hearing impairment (HI) was identified as the potentially most important modifiable risk factor. Even though HI is considered an important modifiable risk factor, the evidence regarding the association between HI and dementia risk is still limited.

Official Title
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Modifiable Risk Factors and Dementia - A Study Examining the Association Between Hearing Impairment in Mid-life and Cognitive Impairment in the HUNT4 70+ Study

Conditions
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Dementia, Hearing Loss

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Living in designated area Exclusion Criteria: None

Ages Eligible for Study
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Minimum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| HUNT4 70+<br>All inhabitants of Nord-Trøndelag 70 years of age or older were invited to participate in HUNT4 70+. | |
| HUNT Trondheim 70+<br>All inhabitants of one district in Trondheim 70 years of age or older were invited to participate in HUNT4 70+. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of dementia diagnosis in the HUNT 70+ study | Two clinical and scientific experts will independently set at diagnosis of cognitive impairment or dementia based on all available information applying standard diagnostic criteria Diagnostic and Statistical Manual of Mental Disorders 5 (DSM-5). | 2017-2019 | 
| Rate of Minimal Cognitive Impairment (MCI) in the HUNT 70+ study | Two clinical and scientific experts will independently set at diagnosis of cognitive impairment or dementia based on all available information applying standard diagnostic criteria DSM-5. | 2017-2019 | 
| Rate of cognitive impairment defined as age- and education-adjusted thresholds on cognitive assessments scales | The participants have been assessed with the Montreal Cognitive Assessment scale and the ten-word recall test | 2017-2019 |