Association between diabetes mellitus and regional brain atrophy in a general older Japanese population: the Hisayama Study

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K16524
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 52010:General internal medicine-related
• Research Institution: Kyushu University
• Principal Investigator: Hirabayashi Naoki 九州大学, 伊都診療所, 講師 (20784474)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 糖尿病 / 糖負荷後2時間血糖値 / 脳部位別灰白質容積 / voxel based morphometry / 地域高齢住民

Outline of Final Research Achievements

We investigated the associations of diabetes and related parameters with regional gray matter volumes and gray matter atrophy patterns using voxel-based morphometry (VBM) among 1,189 community-dwelling Japanese aged 65 years or over. Participants with diabetes had significantly lower gray matter volumes in the frontal lobe, temporal lobe, insula, deep gray matter structures, and cerebellum than participants without diabetes after adjusting for potential confounders. In the VBM analysis, the increased 2-h postload glucose levels correlated with atrophy of the bilateral superior, middle, inferior gyri, bilateral temporal poles, bilateral insulae, left parietal operculum, right opercular part of the inferior frontal gyrus, and right thalamus. In contrast, there were no significantly decreased gray matter areas that were correlated with higher fasting plasma glucose levels.

Free Research Field

Neuroepidemiology、心身医学

Academic Significance and Societal Importance of the Research Achievements

糖尿病と脳構造変化の関係を検討した疫学研究の成績が散見されるが、全脳容積、海馬容積についての報告が多く、地域住民を対象とした糖尿病と脳の部位別の容積との関連を詳細に検討した研究は少ない。久山町の頭部MRI検査を含む疫学調査の成績を用いて、糖尿病は前頭葉、側頭葉、島、深部灰白質、小脳の灰白質萎縮の危険因子であることが示唆され、とくに食後高血糖の指標である糖負荷後2時間血糖値が灰白質萎縮と強く関連することが明らかとなった。本研究結果は認知症の病態解明やその予防対策の一助になると考えられる。