低栄養と咬合支持の崩壊

低栄養と咬合支持の崩壊の放置（歯がないのに義歯を入れていない）の関連を在宅虚弱高齢者を対象に調査した論文を紹介します。日本歯科大学の菊谷先生の論文です。

Kikutani T, Yoshida M, Enoki H, Yamashita Y, Akifusa S, Shimazaki Y, Hirano H, Tamura F. Relationship between nutrition status and dental occlusion in community-dwelling frail elderly people. Geriatr Gerontol Int. 2012 Apr 11. doi: 10.1111/j.1447-0594.2012.00855.x. [Epub ahead of print]

リサーチクエスチョンは以下の通りです。

P：在宅虚弱高齢者（介護保険のサービスを利用している）で
E：栄養状態が悪いと
C：栄養状態がよい場合と比較して
O：咬合支持が悪い

栄養状態はMNA-SFで評価しています。咬合支持はA：天然歯列で機能良好、B：部分義歯もしくは総義歯を使用しているが機能良好、C：義歯を使用していなく機能不良の3段階に分類しています。

結果ですが、716人の在宅虚弱高齢者のうち、栄養状態良好251人、低栄養のおそれあり370人、低栄養95人でした。栄養状態良好群とその他の2群に分類して多変量解析を行うと、栄養状態と性別、ADL（Barthel Index）、咬合支持に有意な関係を認めました。

以上より在宅虚弱高齢者では、咬合支持の崩壊は低栄養のリスク因子であると結論付けています。

横断研究ですので、咬合支持の崩壊と低栄養の因果関係はわかりませんが、関連が示唆されます。MNA-SF以外の栄養評価項目（体重、BMIのデータ）があると、よりわかりやすいのではと感じました。統計手法には若干疑問がありますが、まずは自分が研究を頑張らないと…と思います。

Abstract
Aim:  This study aimed to determine the risk of malnutrition in some communities where the frail elderly receive public long-term care insurance. We also clarified the dental problems in those at risk of malnutrition.

Methods:  A total of 716 frail elderly who lived in eight cities in Japan (240 males and 476 females with a mean age of 83.2 ± 8.6 years) were divided into three groups according to Mini Nutritional Assessment short form results: well nourished, at risk of malnutrition and malnourished. They were also divided into three groups in terms of remaining teeth occlusion and denture occlusion: group A, natural dentition with adequate function; group B, partially or fully edentulous, but maintaining functional occlusion with dentures in either or both jaws; and group C, functionally inadequate occlusion with no dentures. The relationship between nutrition status and dental occlusion was evaluated using logistic regression analysis with sex, age, activities of daily living and cognitive function as covariates.

Results:  The number of participants in each of the groups was as follows: 251 well nourished, 370 at risk of malnutrition and 95 malnourished. When they were divided into just two groups, (i) well nourished and (ii) at risk of malnutrition plus malnourished, in order to study malnutrition risk factors, there were significant relationships between their nutritious status and sex, Barthel index, and occlusion.

Conclusion:  This large-scale cross-sectional survey showed that loss of natural teeth occlusion was a risk factor for malnutrition among community-dwelling frail elderly.