創傷治癒と悪液質

もう1つ、創傷治癒と悪液質に関する論文を紹介します。

Michael FY Ng. Cachexia – an intrinsic factor in wound healing.
Int Wound J 2010; 7:107–113

私が知る限り、創傷治癒と低栄養に関する論文は私が以前執筆したものを含めて多数ありますが、創傷治癒と悪液質の関連を考察した論文はこれがはじめてだと思います。

単なるエネルギー摂取量不足である飢餓と悪液質は別の概念ですので、創傷治癒においても当然、別の概念として考えなければいけません。例えばTNF-αは悪液質で増加することが多いサイトカインですが、創傷治癒にも悪影響を認めます。褥瘡と栄養の関連に関心がある方には、かなり面白い論文だと思います。

抄録だけは面白さが十分伝わらないと思いましたので、論文のKeyPointも英語のままですが掲載しました。単なる低栄養の栄養改善ではなく、悪液質対策（EPA・エイコサペンタエン酸投与など）が悪液質患者の創傷治癒に有利に働く可能性があります。

褥瘡治療のためにEPAを投与するという時代も近いのかもしれません。

ABSTRACT
Systemic diseases are intrinsic factors that alter and may impair the wound healing process. Cachexia is a manifestation of systemic, often chronic, diseases and is characterised by systemic inflammation, appetite suppression and skeletal muscle wasting. Anorexia in cachectic states is commonly associated with malnutrition. Malnutrition may cause impaired healing. Therefore, it would follow that cachexia could influence wound healing because of reduced food intake. However, the lack of response to measures to reverse cachexia, such as supported nutrition, would suggest that a direct causal link between anorexia and weight loss in cachexia is too simple a model. To date, there is no published literature that examines the role of cachexia in human wound healing specifically. This article aims to demonstrate that cachexia is an intrinsic factor in wound healing. The role of the common mediators in wound healing and in cachexia are compared – specifically inflammation, including the nitric oxide synthase pathway, collagen deposition and reepithelialisation.

Key Points
• cachexia is a manifestation of systemic, often chronic, diseases such as neoplasms, rheumatoid arthritis, chronic heart failure and chronic obstructive pulmonary disease and is characterised by systemic inflammation, appetite suppression, and skeletal muscle wasting

• malnutrition may cause impaired healing. Therefore, it would follow that cachexia could influence wound healing because of reduced food intake

• the premise of this essay is that cachexia is an extrinsic factor that affects wound healing via anorexia and undernutrition, and cachexia is an intrinsic factor because its mediators are similar to those essential in wound healing

• this article will compare the role of the common mediators in wound healing and in cachexia – specifically inflammation, including the nitric oxide synthase (NOS) pathway, collagen deposition and reepithelialisation

• it would seem that high levels of circulating cytokines, such as IL-6 and TNFα, and activation of the NOS pathway cause impaired wound healing and cachexia

• experimental evidence suggests TNFα suppresses collagen production and keratinocyte mobility

• the effect on wound healing and cachexia in humans receiving anti-TNFα therapy is subject to debate because of the relationship between inflammation, infection and TNFα levels

• in rodents, and perhaps in humans, activin and myostatin contribute to weight loss and muscle wasting in cachexia

• activin, in particular, may cause overgranulation and altered epithelial migration

• a consensus of the definition of cachexia should be sought

• there is currently no successful method of countering cachexia and its effects onwound healing because of the complexity of the process and lack of research evidence

• by understanding how cachexia affects wound healing in humans, it may lead to effective therapy that will improve the quality of life of those affected by cachexia