在宅高齢嚥下障害は低栄養・下気道感染の危険因子

在宅高齢者で嚥下障害は低栄養と下気道感染の危険因子であるという論文を紹介します。

Serra-Prat M, Palomera M, Gomez C, Sar-Shalom D, Saiz A, Montoya JG, Navajas M, Palomera E, Clavé P. Oropharyngeal dysphagia as a risk factor for malnutrition and lower respiratory tract infection in independently living older persons: a population-based prospective study. Age Ageing. 2012 May;41(3):376-81.

リサーチクエスチョンは、

P：70歳以上の在宅高齢者で（254人、平均78歳）
E：嚥下障害のある方は（V-VSTで評価）
C：嚥下障害のない方と比較して
O：低栄養（MNAで評価）と下気道感染（臨床記録）が多い
D：コホート研究

です。

volume-viscosity swallow test (V-VST)は下記のブログを参照してください。日本でこれをそのまま行うことはないと思います。

V-VSTによる嚥下スクリーニング
http://rehabnutrition.blogspot.jp/2011/05/v-vst.html

結果ですが、抄録しか読めていないので嚥下障害のある方が何人かは不明です。嚥下障害のある方では嚥下障害のない方と比較して、1年後に低栄養もしくは低栄養のおそれありの方が有意に多く、下気道感染も有意に多い（40％対21.8％）でした。

これより在宅高齢者で嚥下障害は低栄養と下気道感染の危険因子であるという結論です。在宅高齢者では定期的に嚥下障害の有無をスクリーニング、治療すべきとしています。

在宅高齢者で嚥下障害と栄養障害の有病割合を調査の上、嚥下障害と健康障害（下気道感染）の関連を明らかにした点で、意味があると考えます。今後は日本で同様な研究を行い、在宅でどのような嚥下・栄養などの介入を行えば、健康障害を少なくできるかが課題です。

Abstract
OBJECTIVE: to assess the role of oropharyngeal dysphagia (OD) as a risk factor for malnutrition and/or lower respiratory tract infection (LRTI) in the independently-living population of 70 years and over.

DESIGN: a population-based cohort study. Subjects and setting: persons 70 years and over in the community (non-institutionalised) were randomly selected from primary care databases.

MEASUREMENTS: the volume-viscosity swallow test (V-VST) was administered by trained physicians at baseline to identify subjects with clinical signs of OD and impaired safety or efficacy of swallow. At the one year follow-up visit, hand grip, functional capacity (Barthel score), nutritional status (mini nutritional assessment, MNA) and LRTI (clinical notes) were assessed.

RESULTS: two hundred and fifty-four subjects were recruited (46.5% female; mean age, 78 years) and 90% of them (227) were re-evaluated one year later. Annual incidence of 'malnutrition or at risk of malnutrition' (MNA <23.5) was 18.6% in those with basal signs of OD and 12.3% in those without basal signs of OD (P = 0.296). However, prevalent cases of 'malnutrition or at risk of malnutrition' at follow up were associated with basal OD (OR = 2.72; P = 0.010), as well as with basal signs of impaired efficacy of swallow (OR = 2.73; P = 0.015). Otherwise, LRTI's annual incidence was higher in subjects with basal signs of impaired safety of swallow in comparison with subjects without such signs (40.0 versus 21.8%; P = 0.030; OR = 2.39).

CONCLUSIONS: OD is a risk factor for malnutrition and LRTI in independently living older subjects. These results suggest that older persons should be routinely screened and treated for OD to avoid nutritional and respiratory complications.