King Daniel A, Cordova Francis, Scharf Steven M
Division of Pulmonary and Critical Care, University of Maryland, MD 21201, USA.
Proc Am Thorac Soc. 2008 May 1;5(4):519-23. doi: 10.1513/pats.200707-092ET.
It is clear that being underweight is a poor prognostic sign in chronic obstructive pulmonary disease (COPD). It is also clear that undernutrition is at least in part associated with the severity of airflow obstruction. While both weight and body mass index are useful screening tools in the initial nutritional evaluation, fat-free mass (FFM) may be a better marker of undernutrition in patients with COPD. The causes of cachexia in patients with COPD are multifactorial and include decreased oral intake, the effect of increased work of breathing due to abnormal respiratory mechanics, and the effect of chronic systemic inflammation. Active nutritional supplementation in undernourished patients with COPD can lead to weight gain and improvements in respiratory muscle function and exercise performance. However, long-term effects of nutritional supplementation are not clear. In addition, the optimal type of nutritional supplementation needs to be explored further. The role of novel forms of treatment, such as androgens or appetite stimulants designed to increase FFM, also needs to be further studied. Thus, in the absence of definitive data, it cannot be said that long-term weight gain, either using enhanced caloric intake, with or without anabolic steroids or appetite stimulants, offers survival or other benefits to patients with COPD. However, there are indications from single-center trials that this is an avenue well worth exploring.
很明显，体重过轻在慢性阻塞性肺疾病（COPD）中是一个不良的预后指标。同样明显的是，营养不良至少部分与气流阻塞的严重程度相关。虽然体重和体重指数在初始营养评估中都是有用的筛查工具，但去脂体重（FFM）可能是COPD患者营养不良的更好指标。COPD患者恶病质的原因是多因素的，包括口服摄入量减少、异常呼吸力学导致的呼吸功增加的影响以及慢性全身炎症的影响。对营养不良的COPD患者进行积极的营养补充可导致体重增加，并改善呼吸肌功能和运动表现。然而，营养补充的长期效果尚不清楚。此外，营养补充的最佳类型需要进一步探索。新型治疗形式的作用，如旨在增加FFM的雄激素或食欲刺激剂，也需要进一步研究。因此，在缺乏确凿数据的情况下，不能说使用增加热量摄入（无论是否使用合成代谢类固醇或食欲刺激剂）实现的长期体重增加会为COPD患者带来生存或其他益处。然而，单中心试验表明这是一个非常值得探索的途径。
