Development of an early diagnosis of Alzheimer's disease based on olfactory impairment using a novel imaging evaluation method

2023 Fiscal Year Final Research Report

• Project/Area Number: 16K11219
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Otorhinolaryngology
• Research Institution: Kanazawa Medical University
• Principal Investigator: MIWA Takaki 金沢医科大学, 医学部, 教授 (20229909)
• Co-Investigator(Kenkyū-buntansha): 川崎 康弘 金沢医科大学, 医学部, 教授 (80242519) ; 志賀 英明 金沢医科大学, 医学部, 准教授 (80436823) ; 張田 雅之 金沢医科大学, 医学部, 助教 (40769105)
• Project Period (FY): 2016-04-01 – 2024-03-31
• Keywords: アルツハイマー病 / 軽度認知障害 / 嗅覚障害 / 嗅覚検査 / MRI / フレイル / サルコペニア

Outline of Final Research Achievements

It is known that olfactory dysfunction (OD) appears before the onset or early stage of dementia, such as mild cognitive impairment (MCI) and Alzheimer's disease (AD). Still, OD is also reduced in healthy elderly. In this study, we investigated whether it is possible to differentiate between healthy elderly people and patients with MCI and AD based on olfactory tests and diagnostic imaging. Compared to healthy elderly people, olfactory function decreased with the progression of MCI and AD. Brain MRI also showed a reduction in the volume of the olfactory bulb, frontal lobe, hippocampus, amygdala, and entorhinal cortex. In an olfactory identification test using 12 odors familiar to the Japanese, curry was the most effective in differentiating MCI and AD from normal subjects. These results suggest if OD is determined through screening during health check-ups and physical examinations, detailed examination with MRI is indicated which could lead to early diagnosis of dementia.

Free Research Field

耳鼻咽喉科学

Academic Significance and Societal Importance of the Research Achievements

今回の研究では、嗅覚低下がAD、MCIと関連するとともに、フレイル、サルコペニアとも関連を持つことが明らかとなった。AD、MCIの早期発見に嗅覚検査のカレーのにおいが有効であるとともに、フレイルにはカレー、メントール、墨汁、みかんの組み合わせが、サルコペニアには材木、ひのき、焦げたニンニクの組み合わせがそれらの存在を疑うに有効であった。嗅覚検査に用いたOpen Essenceは被検者自らが実施可能な簡便な検査であり、今後、健康診断や人間ドックなどで導入することにより、これらの疾患、病態の早期発見に繋がり、アンチエイジングに貢献できる可能性が示唆された。