The evaluation of relationship between periodontitis and cerebral amyloid-beta accumulation

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K07659
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 52040:Radiological sciences-related
• Research Institution: Research Institute, Shiga Medical Center
• Principal Investigator: Okuyama Chio 滋賀県立総合病院(研究所), 画像研究部門, 専門研究員 (40347464)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 慢性歯周炎 / アミロイド / FPYBF-2 / PET / 歯周炎菌

Outline of Final Research Achievements

We evaluated the correlation between periodontitis and cerebral amyloid tracer uptake in 49　subjects with normal cognitive function, who were classified based on the dental condition into 4 groups: normal (n=9), gingivitis (n=14), moderate (n=12), and severe periodontitis (n=14). Dental examinations and amyloid PET using 18F-FPYBF-2 were performed. Among these groups, no significant differences were seen in the age, MMSE score, or PET results. Periodontitis bacteria: Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and Actinobacillus actinomycetemcomitans were measured from periodontal pocket specimens. PET showed no visually positive cases except for one case with focal accumulation in the right occipital lobe. Quantitative evaluation showed no significant difference between groups or the existence of each bacterium. In subjects with normal cognitive function, no significant relationship between periodontitis and amyloid deposition was observed.

Free Research Field

核医学

Academic Significance and Societal Importance of the Research Achievements

これまでのげっ歯類を用いた研究にて、歯周炎菌の存在が認知症の原因となる脳内アミロイドの蓄積と関連するとの報告が認められていたが、認知機能正常の75歳未満の被験者を対象に、歯肉の健康状態・歯周炎菌の有無と、アルツハイマー病の基本病理である脳内アミロイドの分布を調べたヒトを対象とする今回の検討において、歯周炎菌の存在や歯周炎の罹患が直接的にアミロイドの蓄積をもたらすという結果は見いだせなかった。