肝臓リハビリテーション

Hepatic Rehabilitation

はじめに

　2010年，身体障害者福祉法で7番目の内部障害として肝臓機能障害が新たに制定された．わが国の慢性肝炎や肝硬変の患者の多くは肝炎ウイルスによるものであり，中でもC型肝炎ウイルスによるものが最も多く，次いでB型肝炎ウイルスによるものが多い．非アルコール性脂肪性肝疾患（nonalcoholic fatty liver disease：NAFLD）は，単純脂肪肝から脂肪肝炎（nonalcoholic steatohepatitis：NASH），肝硬変を含む一連の代謝性肝障害である．メタボリックシンドロームの表現型の1つであり，多くの先進国で肥満人口の増加に伴い，慢性肝臓病として主要な地位を占めるようになってきている．本稿では，「肝臓リハビリテーション」として，この肝臓機能障害へのリハビリテーション（以下，リハ）について概説する．

Abstract : Severe liver disease has been recently recognized as a physical disability in Japan. The six minute walk distance (6MWD) was identified as an independent predictor of survival in patients with liver cirrhosis, suggesting that physical function may serve as an additional prognostic marker in liver disease. The definition of “hepatic rehabilitation” has not yet been established, but rehabilitation for liver disease can improve deconditioning and QOL. Non-alcoholic fatty liver disease (NAFLD) is a series of diseases ranging from asymptomatic steatosis with or without elevated transaminases to non-alcoholic steatohepatitis (NASH) and cirrhosis. NAFLD is a phenotype of metabolic syndrome and closely associated with obesity and insulin resistance. Paralleling the increasing prevalence of obesity in adults and children, NAFLD is probably the most common cause of chronic liver disease in developed countries. The first line of treatment for NAFLD comprises lifestyle changes including caloric restriction, improved diet composition and exercise. Although weight reduction has been suggested as an effective treatment for overweight patients with NAFLD, there is little evidence to support weight reduction alone as an effective therapy. Exercise reduces levels of liver enzymes and steatosis regardless of weight reduction and the independent effect of exercise on liver steatosis supports its use as a practical intervention in NAFLD. Furthermore, beneficial effects of high intensity exercise for NAFLD have been reported. Rehabilitation doctors should evaluate each patient's problems and provide an appropriate exercise protocol. Comprehensive rehabilitation is beneficial for liver disease, and the importance of such rehabilitation will probably increase in the future.