がん化学療法に伴う味覚閾値の変化に関する研究

Study in the Change in Taste Threshold Associated with Cancer Chemotherapy

要　旨

　本研究の目的は，がん化学療法の経過に伴う患者の甘味，塩味，酸味，苦味閾値の変化とその要因を明らかにすることである．対象者は，これから化学療法を受ける入院中の血液・造血器腫瘍患者45名．味覚検査用試薬を用い滴下法により治療前・治療中・治療後の計3回，縦断的に味覚閾値を測定し，口腔内の状態を観察法により把握した．患者属性，使用薬剤などは診療録により収集を行った．味覚閾値を従属変数，口腔内の状態や使用薬剤など11要因を独立変数として重回帰分析を行い，以下の結果を得た．

　1．甘味・塩味・酸味・苦味のうち，がん化学療法の影響を受けていたのは塩味であった．塩味閾値の平均は治療前2.6，治療中2.4，治療後3.0であり，治療後は治療前，治療中に比べ有意に上昇し，鈍感になっていた．

　2．重回帰分析の結果，治療後の塩味鈍化をもたらす要因は年齢と抗がん抗生物質であった．加齢，抗がん抗生物質使用者では明らかに塩味に対する鈍化が認められた．

　以上より，味覚変化からくる食物嫌悪を予防するためには，化学療法後の食事は，塩味の鈍化に対応し，塩味を集中させる．一時的に少し多めに塩分を加える介入が必要である．特に，高齢者や抗がん抗生物質使用者では，治療後，塩味が鈍感になりやすく，綿密な観察とアセスメント，食事介入が不可欠であることが示唆された．

Abstract

　The purpose of this study is to identify the factors affecting taste threshold for sweetness, saltiness, sourness and bitterness associated with cancer chemotherapy. Forty-five subjects hospitalized for chemotherapy were studied using drops of reagents for taste studies. The taste evaluation was performed three times, before, during and after chemotherapy. Patient background, intraoral conditions and chemotherapy drugs were recorded through observation and medical records. Multiple regression analysis was performed using taste threshold as a dependent variable and eleven factors including intraoral state and chemotherapy drugs as independent variables.

　1. Taste threshold for saltines was greatly affected by cancer chemotherapy. The average thresholds of taste for saltiness were 2.6, 2.4 and 3.0 before, during and after treatment respectively. The patients become significantly less sensitive to saltiness after treatment than before or during treatment.

　2. Multiple regression analysis showed correlation between decrease in taste sensitiveness and age and antibiotics used. The older the patients, the higher the threshold. And patients using antitumor antibiotics were significantly less sensitive to saltiness than those without antibiotics.

　The above results showed that the meals served to the patients after chemotherapy should be temporarily more salty than usual in order to prevent decrease in the amount of food eaten. Since elderly patients and patients on antitumor antibiotics are less sensitive to saltiness, the early intervention is indispensable through careful observation and assessment.