高齢血液透析患者に対する口腔機能訓練の効果 : 安静時唾液分泌量の変化からみた検討

高齢血液透析患者の口腔乾燥には，日常的な水分摂取の制限と唾液腺自体の加齢性変化が関係していると考えられる．高齢血液透析患者の口腔乾燥改善には，まず十分な安静時唾液の分泌が必要と考え，それを促す手法の一つとして口腔機能訓練に着目した．本研究は，高齢血液透析患者に対して継続的な口腔機能訓練を行い，安静時唾液量の変化から訓練の効果を検証することを目的とした．
研究参加の同意が得られた軽度以上の口腔乾燥を有する高齢血液透析患者を，無作為に2群に分けた．歯科衛生士による口腔機能訓練（唾液腺マッサージ，舌運動訓練）を透析中（週3回）に12週間行った群を介入群，行わなかった群を対照群とした．研究開始前，2週後，4週後，8週後および12週後に，口腔内湿潤度と安静時唾液量を測定した．研究を完了した54名（介入群28名，対照群26名）について，群内および群間の比較には二元配置分散分析を，計測回ごとの多重比較にはBonfferoni法を用いて，統計解析を行った．
口腔機能訓練の実施による変化を検証した結果，口腔内湿潤度は，介入群の主効果および対照群との交互作用も有意であった（F（1,52）＝22.3，p＝0.03，F（4）＝3.5，p＝0.008）．群内の多重比較の結果，介入群は研究開始時と比較して，4週後以降で有意差が認められた（p＜0.05，p＜0.001，p＜0.05）が，対照群は有意差が認められなかった．安静時唾液は，介入群の主効果および対照群との交互作用も有意（F（1,52）＝18.6，p＜0.001，F（3）＝5.3，p＝0.002）であった．群内の多重比較の結果，介入群において，研究開始前と比較して4週後以降（p＜0.05，p＜0.001，p＜0.001）に有意な増加が認められた．一方，対照群において，2週後と12週後，4週後と12週後に有意な増加が認められた（p＜0.05，p＜0.05）．以上より，高齢血液透析患者に対する長期間（4週間以上）の唾液腺マッサージや舌運動訓練による口腔機能訓練は，安静時唾液分泌量を増加させる可能性が示唆された．

Introduction:　Daily fluid restriction and aging-related atrophy of saliva glands might cause dry mouth in older hemodialysis patients. We hypothesized that greater saliva secretion is needed to relieve dry mouth and that this could be achieved by providing oral functional training to patients. The aim of this study was to investigate changes in resting saliva secretion after performing oral functional training for older hemodialysis patients with mild dry mouth.
Materials and Methods:　Hemodialysis patients with mild dry mouth at Kawashima Hospital gave informed consent to participate in the study. They were then randomly divided into an intervention group (n＝31) and a control group (n＝30). The intervention group was provided oral functional training by a dental hygienist, including saliva gland massage for 30 s and tongue lateral movement for 12 weeks during dialysis treatment. The control group did not receive the training. Overall, 54 participants completed the experiment. Oral wetness was measured using a KISO-WeT Tester, and the amount of resting saliva secreted in 30 s was collected in a cotton roll and weighed. Measurements were implemented at baseline and at 2, 4, 8, and 12 weeks after starting the regimen.
Results and Discussion:　In the intervention group, oral wetness at 4, 8, and 12 weeks was significantly higher than that at baseline (p＜0.05, p＜0.001, p＜0.05, respectively). No statistically significant differences were found in the control group. In the intervention group, the amounts of saliva secreted at 4, 8, and 12 weeks were significantly greater than that at baseline (p＜0.05, p＜0.001, p＜0.001, respectively). In the control group, the amount of saliva secreted at 12 weeks was significantly more than that at 2 and 4 weeks (p＜0.05, p＜0.05, respectively).
Conclusion:　We concluded that performing oral functional training, which included salivary gland massage and tongue movement training for 4 or more weeks, could increase the amount of resting saliva secretion in older hemodialysis patients with mild dry mouth.