高齢者集団における歯周保健と認知機能障害との相関に関するメタ分析

Meta Analysis of the Correlation between Periodontal Health and Cognitive Impairment in the Older Population.

抄録

目的:

高齢者における口腔ケアの観点から認知機能障害を予防するためのエビデンスを提供するために、高齢者集団における歯周保健と認知機能障害との相関関係を検討すること。

OBJECTIVE: To explore the correlation between periodontal health and cognitive impairment in the older population to provide the evidence for preventing cognitive impairment from the perspective of oral health care in older adults.

方法:

PubMed、Embase、Cochrane Library、Web of Science、China National Knowledge Infrastructure、Wanfang Data、China Science and Technology Journal Database、China Biomedical Literature Databaseで包括的な検索を行い、高齢者における歯周健康と認知機能障害との関連に関する横断的および縦断的コホート研究を含めた。検索は2023年4月に完了した。対象研究の質評価とデータ整理を行った後、Review Manager 5.4を用いてメタ解析を行った。

METHODS: A comprehensive search was conducted in PubMed, Embase, the Cochrane Library, the Web of Science, the China National Knowledge Infrastructure, Wanfang Data, the China Science and Technology Journal Database, and the China Biomedical Literature Database, to include both cross-sectional and longitudinal cohort studies on the association between periodontal health and cognitive impairment in older adults. The search was completed in April 2023. Following quality assessment and data organization of the included studies, meta-analysis was performed using Review Manager 5.4.

結果:

4つの側面（歯周炎、歯牙喪失、咬合支持、咀嚼能力）から歯周健康を包括的に評価し、認知障害（軽度認知障害、アルツハイマー病、全死因性認知症を含む）をアウトカム変数とした、合計4,246,608人の患者を含む22の研究が対象となった。メタアナリシスによると、歯周健康度の低い高齢者における認知機能障害のリスクは、交絡因子を調整した後、歯周炎を有する高齢者の方が有意に高かった（OR=1.45、95％CI：1.20-1.76、P＜0.001）、歯の喪失（OR＝1.80、95％CI：1.50-2.15、P＜0.001）、咬合支持力の低下（OR＝1.87、95％CI：1.29-2.70、P＝0.001）、咀嚼能力の低下（OR＝1.39、95％CI：1.11-1.75、P＝0.005）であった。認知機能障害のリスクは、低歯列の高齢者では高歯列の高齢者よりも高かった。サブグループ解析の結果、残存歯数の少ない高齢者は、残存歯数の多い高齢者に比べて認知障害発症リスクが高いことが明らかになった。64、95％CI：1.13-2.39、P＝0.01）、（0-8歯と比較して9-28歯）（OR＝1.13、95％CI：1.06-1.20、P＜0.001）、（0-18歯と比較して19-28歯）（OR＝2.52、95％CI：1.32-4.80、P＝0.005）、（0-27歯と比較して28歯）（OR＝2.07、95％CI：1.54-2.77、P＜0.001）であった。さらに、高齢者における歯の喪失は、軽度認知障害（OR=1.66、95％CI：1.43-1.91、P<0.001）および全死因性認知症（OR=1.35、95％CI：1.11-1.65、P=0.003）のリスクを有意に増加させたが、歯の喪失とアルツハイマー病のリスクとの相関は有意ではなかった（OR=3.89、95％CI：0.68-22.31、P=0.13）。

RESULTS: Twenty-two studies involving a total of 4,246,608 patients were included to comprehensively assess periodontal health from four dimensions (periodontitis, tooth loss, occlusal support, and masticatory ability), with the outcome variable of cognitive impairment (including mild cognitive impairment, Alzheimer's disease and all-cause dementia). Meta-analysis showed that, compared to those of periodontally healthy older adults, the risk of cognitive impairment in older adults with poor periodontal health, after adjusting for confounders, was significantly greater for those with periodontitis (OR=1.45, 95% CI: 1.20-1.76, P<0.001), tooth loss (OR=1.80, 95% CI: 1.50-2.15, P<0.001), compromised occlusal support (OR=1.87, 95% CI: 1.29-2.70, P=0.001), and reduced masticatory ability (OR=1.39, 95% CI: 1.11-1.75, P=0.005). The risk of cognitive impairment was higher in older adults with low-dentition than in those with high-dentition. Subgroup analysis revealed older individuals with fewer remaining teeth were at a higher risk of developing cognitive impairment compared to those with more remaining teeth, as shown by the comparison of number of teeth lost (7-17 teeth compared to 0-6 teeth) (OR=1.64, 95% CI: 1.13-2.39, P=0.01), (9-28 teeth compared to 0-8 teeth) (OR=1.13, 95% CI: 1.06-1.20, P<0.001), (19-28 teeth compared to 0-18 teeth) (OR=2.52, 95% CI: 1.32-4.80, P=0.005), and (28 teeth compared to 0-27 teeth) (OR=2.07, 95% CI: 1.54-2.77, P<0.001). In addition, tooth loss in older adults led to a significantly increased risk of mild cognitive impairment (OR=1.66, 95% CI: 1.43-1.91, P<0.001) and all-cause dementia (OR=1.35, 95% CI: 1.11-1.65, P=0.003), although the correlation between tooth loss and the risk of Alzheimer's disease was not significant (OR=3.89, 95% CI: 0.68-22.31, P=0.13).

結論:

4つの側面（歯周炎、歯の喪失、咬合支持、咀嚼能力）で評価した歯周健康の不良は、高齢者における認知障害の有意な危険因子である。高齢者では歯の欠損が多いほど認知障害発症のリスクが高く、無歯顎者は特に認知障害に罹患しやすい。アルツハイマー病のリスクがある程度高まることは観察されたが、歯の喪失とアルツハイマー病の発症リスクとの間に有意な関連は認められなかった。歯周健康管理を強化し、高齢者に質の高い口腔ケアサービスを提供することは、認知機能障害の予防に役立つ可能性がある。

CONCLUSION: Poor periodontal health, assessed across four dimensions (periodontitis, tooth loss, occlusal support, and masticatory ability), represents a significant risk factor for cognitive impairment in older adults. The more missing teeth in older adults, the higher risk of developing cognitive impairment, with edentulous individuals particularly susceptible to cognitive impairment. While a certain degree of increased risk of Alzheimer's disease was observed, no significant association was found between tooth loss and the risk of developing Alzheimer's disease. Enhancing periodontal health management and delivering high-quality oral health care services to older adults can help prevent cognitive impairment.