高齢女性における認知機能と咀嚼の関係

Relationship between cognitive function and mastication in elderly females.

抄録

日本では認知症高齢者が急増している。いくつかの動物実験で、高齢者の咀嚼機能低下と認知機能障害との関係が指摘されている。しかし、これを検討した疫学研究は少ない。本研究では、疫学的アプローチを用いて、65歳以上の認知症患者44名と非認知症患者44名を対象に、この関係を調査した。年齢と、歩行、食事、排泄、入浴、着替えなどの基本的な日常生活動作は、両群で一致させた。認知機能障害は改訂長谷川式認知症評価尺度を用いて測定した。咀嚼機能は、存在歯数、最大咬合力、咬合接触面積、咀嚼スコアで評価した。認知機能正常者の存在歯数は、認知機能障害者よりも有意に多かった（P＜0.05）。さらに、認知正常者の最大咬合力、咬合接触面積、咀嚼スコアは、認知障害者のそれよりも有意に高かった（P＜0.01）。これらの結果から、高齢者の咀嚼機能は認知状態と関連していることが示唆された。

In Japan, the elderly population suffering from dementia is rapidly increasing. Several animal studies have indicated a relationship between reduced masticatory function in the elderly subject and cognitive impairment. However, epidemiological studies examining this have been scarce. Using an epidemiological approach, the present study investigated this relationship in 44 females with and 44 without dementia, all aged over 65 years. Age and basic activities of daily living, such as walking, eating, excreting, bathing and dressing, were matched in the two groups. Cognitive impairment of the subjects was measured using the revised Hasegawa Dementia Rating Scale. Masticatory function was assessed in terms of the number of teeth present, maximum bite force, occlusal contact area, and mastication score. The number of teeth present in cognitively normal subjects was significantly higher than in cognitively impaired subjects (P < 0.05). In addition, maximum bite force, occlusal contact area, and mastication scores of cognitively normal subjects were significantly higher than those of cognitively impaired subjects (P < 0.01). These results suggest that masticatory function in the elderly person is associated with cognitive status.